Sample records for rotted cassava roots

  1. Root rots

    Treesearch

    Kathryn Robbins; Philip M. Wargo

    1989-01-01

    Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and...

  2. Corky root rot

    USDA-ARS?s Scientific Manuscript database

    Corky root rot (corchosis) was first reported in Argentina in 1985, but the disease was presumably present long before that. The disease occurs in most alfalfa-growing areas of Argentina but is more common in older stands. In space-planted alfalfa trials scored for root problems, corky root rot was ...

  3. Cassava root membrane proteome reveals activities during storage root maturation.

    PubMed

    Naconsie, Maliwan; Lertpanyasampatha, Manassawe; Viboonjun, Unchera; Netrphan, Supatcharee; Kuwano, Masayoshi; Ogasawara, Naotake; Narangajavana, Jarunya

    2016-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crops of Thailand. Its storage roots are used as food, feed, starch production, and be the important source for biofuel and biodegradable plastic production. Despite the importance of cassava storage roots, little is known about the mechanisms involved in their formation. This present study has focused on comparison of the expression profiles of cassava root proteome at various developmental stages using two-dimensional gel electrophoresis and LC-MS/MS. Based on an anatomical study using Toluidine Blue, the secondary growth was confirmed to be essential during the development of cassava storage root. To investigate biochemical processes occurring during storage root maturation, soluble and membrane proteins were isolated from storage roots harvested from 3-, 6-, 9-, and 12-month-old cassava plants. The proteins with differential expression pattern were analysed and identified to be associated with 8 functional groups: protein folding and degradation, energy, metabolism, secondary metabolism, stress response, transport facilitation, cytoskeleton, and unclassified function. The expression profiling of membrane proteins revealed the proteins involved in protein folding and degradation, energy, and cell structure were highly expressed during early stages of development. Integration of these data along with the information available in genome and transcriptome databases is critical to expand knowledge obtained solely from the field of proteomics. Possible role of identified proteins were discussed in relation with the activities during storage root maturation in cassava.

  4. Response of the Andean diversity panel to root rot in a root rot nursery in Puerto Rico

    USDA-ARS?s Scientific Manuscript database

    The Andean Diversity Panel (ADP) was evaluated under low-fertility and root rot conditions in two trials conducted in 2013 and 2015 in Isabela, Puerto Rico. About 246 ADP lines were evaluated in the root rot nursery with root rot and stem diseases caused predominantly by Fusarium solani, which cause...

  5. Root rot in sugar beet piles at harvest

    USDA-ARS?s Scientific Manuscript database

    Sugar beet root rots are not only a concern because of reduced yields, but can also be associated with losses in storage. Our primary sugar beet root rot disease problem in the Amalgamated production area is Rhizoctonia root rot. However, this rot frequently only penetrates a short distance past t...

  6. Armillaria root rot

    USDA-ARS?s Scientific Manuscript database

    First described on grapevines in California in the 1880s, Armillaria root rot occurs in all major grape-growing regions of the state. The causal fungus, Armillaria mellea, infects woody grapevine roots and the base of the trunk (the root collar), resulting in a slow decline and eventual death of the...

  7. Control of black walnut root rot diseases in nurseries.

    Treesearch

    Kenneth J. Jr. Kessler

    1982-01-01

    Current nursery methods used to control black walnut root rot diseases are considered in terms of integrated pest management. Suggestions for future root rot control research studies and procedures to minimize root rot problems are provided.

  8. Annosus Root Rot in Eastern Conifers

    Treesearch

    Kathryn Robbins

    1984-01-01

    The fungus Heterobasidion annosum (Fr.) Bref. (= Fomes annosus (Fr.) Karst.) causes a root and butt rot of conifers in many temperate parts of the world. The decay, called annosus root rot, often kills infected conifers; infected trees that survive grow more slowly and are susceptible to windthrow and bark beetle attack.

  9. Cultivar selection for sugarbeet root rot resistance.

    USDA-ARS?s Scientific Manuscript database

    Fungal and bacterial root rots in sugar beet caused by Rhizoctonia solani (Rs) and Leuconostoc mesenteroides subsp. dextranicum (Lm) can lead to root yield losses greater than 50%. To reduce the impact of these root rots on sucrose loss in the field, storage, and factories, studies were conducted t...

  10. Cultivar selection for bacterial root rot in sugar beet

    USDA-ARS?s Scientific Manuscript database

    Bacterial root rot of sugar beet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States, which has frequently been found in association with Rhizoctonia root rot. To reduce the impact of bacterial root rot on sucrose loss in the field, st...

  11. Disease notes - Bacterial root rot

    USDA-ARS?s Scientific Manuscript database

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  12. Cyanogen Metabolism in Cassava Roots: Impact on Protein Synthesis and Root Development.

    PubMed

    Zidenga, Tawanda; Siritunga, Dimuth; Sayre, Richard T

    2017-01-01

    Cassava ( Manihot esculenta Crantz), a staple crop for millions of sub-Saharan Africans, contains high levels of cyanogenic glycosides which protect it against herbivory. However, cyanogens have also been proposed to play a role in nitrogen transport from leaves to roots. Consistent with this hypothesis, analyses of the distribution and activities of enzymes involved in cyanide metabolism provides evidence for cyanide assimilation, derived from linamarin, into amino acids in cassava roots. Both β-cyanoalanine synthase (CAS) and nitrilase (NIT), two enzymes involved in cyanide assimilation to produce asparagine, were observed to have higher activities in roots compared to leaves, consistent with their proposed role in reduced nitrogen assimilation. In addition, rhodanese activity was not detected in cassava roots, indicating that this competing means for cyanide metabolism was not a factor in cyanide detoxification. In contrast, leaves had sufficient rhodanese activity to compete with cyanide assimilation into amino acids. Using transgenic low cyanogen plants, it was shown that reducing root cyanogen levels is associated with elevated root nitrate reductase activity, presumably to compensate for the loss of reduced nitrogen from cyanogens. Finally, we overexpressed Arabidopsis CAS and NIT4 genes in cassava roots to study the feasibility of enhancing root cyanide assimilation into protein. Optimal overexpression of CAS and NIT4 resulted in up to a 50% increase in root total amino acids and a 9% increase in root protein accumulation. However, plant growth and morphology was altered in plants overexpressing these enzymes, demonstrating a complex interaction between cyanide metabolism and hormonal regulation of plant growth.

  13. Cyanogen Metabolism in Cassava Roots: Impact on Protein Synthesis and Root Development

    PubMed Central

    Zidenga, Tawanda; Siritunga, Dimuth; Sayre, Richard T.

    2017-01-01

    Cassava (Manihot esculenta Crantz), a staple crop for millions of sub-Saharan Africans, contains high levels of cyanogenic glycosides which protect it against herbivory. However, cyanogens have also been proposed to play a role in nitrogen transport from leaves to roots. Consistent with this hypothesis, analyses of the distribution and activities of enzymes involved in cyanide metabolism provides evidence for cyanide assimilation, derived from linamarin, into amino acids in cassava roots. Both β-cyanoalanine synthase (CAS) and nitrilase (NIT), two enzymes involved in cyanide assimilation to produce asparagine, were observed to have higher activities in roots compared to leaves, consistent with their proposed role in reduced nitrogen assimilation. In addition, rhodanese activity was not detected in cassava roots, indicating that this competing means for cyanide metabolism was not a factor in cyanide detoxification. In contrast, leaves had sufficient rhodanese activity to compete with cyanide assimilation into amino acids. Using transgenic low cyanogen plants, it was shown that reducing root cyanogen levels is associated with elevated root nitrate reductase activity, presumably to compensate for the loss of reduced nitrogen from cyanogens. Finally, we overexpressed Arabidopsis CAS and NIT4 genes in cassava roots to study the feasibility of enhancing root cyanide assimilation into protein. Optimal overexpression of CAS and NIT4 resulted in up to a 50% increase in root total amino acids and a 9% increase in root protein accumulation. However, plant growth and morphology was altered in plants overexpressing these enzymes, demonstrating a complex interaction between cyanide metabolism and hormonal regulation of plant growth. PMID:28286506

  14. Sugarbeet Cultivar Evaluation for Bacterial Root Rot

    USDA-ARS?s Scientific Manuscript database

    Bacterial root rot of sugarbeet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assa...

  15. Constituents and secondary metabolite natural products in fresh and deteriorated cassava roots.

    PubMed

    Bayoumi, Soad A L; Rowan, Michael G; Beeching, John R; Blagbrough, Ian S

    2010-04-01

    A phytochemical analysis of cassava (Manihot esculenta Crantz) fresh roots and roots suffering from post-harvest physiological deterioration (PPD) has been carried out. The first isolation and identification of galactosyl diacylglycerides from fresh cassava roots is reported, as well as beta-carotene, linamarin, and beta-sitosterol glucopyranoside. The hydroxycoumarin scopoletin and its glucoside scopolin were identified from cassava roots during PPD, as well as trace quantities of esculetin and its glucoside esculin. There is no isoscopoletin in cassava roots during PPD. Copyright 2009 Elsevier Ltd. All rights reserved.

  16. Cultivar Selection for Sugar Beet Root Rot Resistance

    USDA-ARS?s Scientific Manuscript database

    Fungal and bacterial root rots in sugar beet caused by Rhizoctonia solani (Rs) and Leuconostoc mesenteroides subsp. dextranicum (Lm) can lead to root yield losses greater than 50%. To reduce the impact of these root rots on sucrose loss in the field, storage, and factories, studies were conducted t...

  17. Storage root of cassava: Morphological types, anatomy, formation, growth, development and harvest time

    USDA-ARS?s Scientific Manuscript database

    Cassava (Manihot esculenta, Crantz) is considered a starchy root crop that provides staple food for millions of people in tropical and subtropical regions of the world. Research efforts are directed towards genetic breeding and cultivation of cassava to improve cassava storage root starch production...

  18. Modification of cell wall polysaccharides during retting of cassava roots.

    PubMed

    Ngolong Ngea, Guillaume Legrand; Guillon, Fabienne; Essia Ngang, Jean Justin; Bonnin, Estelle; Bouchet, Brigitte; Saulnier, Luc

    2016-12-15

    Retting is an important step in traditional cassava processing that involves tissue softening of the roots to transform the cassava into flour and various food products. The tissue softening that occurs during retting was attributed to the degradation of cell wall pectins through the action of pectin-methylesterase and pectate-lyase that possibly originated from a microbial source or the cassava plant itself. Changes in cell wall composition were investigated during retting using chemical analysis, specific glycanase degradation and immuno-labelling of cell wall polysaccharides. Pectic 1,4-β-d-galactan was the main cell wall polysaccharide affected during the retting of cassava roots. This result suggested that better control of pectic galactan degradation and a better understanding of the degradation mechanism by endogenous endo-galactanase and/or exogenous microbial enzymes might contribute to improve the texture properties of cassava products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Metabolomic, enzymatic, and histochemical analyzes of cassava roots during postharvest physiological deterioration.

    PubMed

    Uarrota, Virgílio Gavicho; Maraschin, Marcelo

    2015-11-05

    Under postharvest physiological deterioration cassava root tubers alter the expression of biosynthetic pathways of certain primary and secondary metabolites, as well as the activity of some scavenging enzymes. Therefore, in this study we hypothesized that cassava cultivars differ as to their physiological responses to deterioration and their biochemical profiles can be an indicative of the tolerance or susceptibility to deterioration. The results corroborate the working hypothesis, revealing that high Levels of phenolic acids, scopoletin, carotenoids, proteins, and augmented activities of guaiacol peroxidase and hydrogen peroxide in non-stored cassava roots can be used as potential biomarkers of cassava deterioration. Cassava physiological deterioration depends on cultivar and many compounds are up and downregulated during storage time. Secondary metabolites, enzymes, scopoletin, scavenging reactive oxygen species, and acidic polysaccharides are activated as responses to the physiological stress induced in root tubers.

  20. Management of Rhizoctonia root and crown rot of subarbeet

    USDA-ARS?s Scientific Manuscript database

    Rhizoctonia root and crown rot is caused by the fungus Rhizoctonia solani and is one of the most severe soil-borne diseases of sugarbeet in Minnesota and North Dakota. Rhizoctonia root and crown rot may reduce yield significantly, and diseased beets may cause problems in storage piles. Fields with...

  1. A diagnostic guide for Fusarium Root Rot of pea

    USDA-ARS?s Scientific Manuscript database

    Fusarium root rot, caused by Fusarium solani f. sp. pisi, is a major root rot pathogen in pea production areas worldwide. Here we provide a diagnostic guide that describes: the taxonomy of the pathogen, signs and symptoms of the pathogen, host range, geographic distribution, methods used to isolate ...

  2. Melatonin attenuates postharvest physiological deterioration of cassava storage roots.

    PubMed

    Ma, Qiuxiang; Zhang, Ting; Zhang, Peng; Wang, Zhen-Yu

    2016-05-01

    Melatonin reportedly increases abiotic and biotic stress tolerance in plants, but information on its in vivo effects during postharvest physiological deterioration (PPD) in cassava is limited. In this study, we investigated the effect of melatonin in regulating cassava PPD. Treatment with 500 mg/L melatonin significantly delayed cassava PPD and reduced the accumulation of hydrogen peroxide (H2O2) while increasing the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), but not ascorbate peroxidase (APX). Transcript analysis further showed that expression of copper/zinc SOD (MeCu/ZnSOD), MeCAT1, glutathione peroxidase (MeGPX), peroxidase 3 (MePX3), and glutathione S-transferases (MeGST) was higher in cassava roots sliced treated with 500 mg/L melatonin than in those not exposed to exogenous melatonin. These data demonstrate that melatonin delays cassava PPD by directly or indirectly maintaining homoeostasis of cellular reactive oxygen species (ROS). We also found that accumulation of endogenous melatonin and the transcript levels of melatonin biosynthesis genes changed dynamically during the PPD process. This finding suggested that endogenous melatonin acts as a signal modulator for maintaining cassava PPD progression and that manipulation of melatonin biosynthesis genes through genetic engineering might prevent cassava root deterioration. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Characters related to higher starch accumulation in cassava storage roots

    PubMed Central

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-01-01

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed. PMID:26892156

  4. Characters related to higher starch accumulation in cassava storage roots.

    PubMed

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-02-19

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed.

  5. Cloning and characterization of a tuberous root-specific promoter from cassava (Manihot esculenta Crantz).

    PubMed

    Koehorst-van Putten, Herma J J; Wolters, Anne-Marie A; Pereira-Bertram, Isolde M; van den Berg, Hans H J; van der Krol, Alexander R; Visser, Richard G F

    2012-12-01

    In order to obtain a tuberous root-specific promoter to be used in the transformation of cassava, a 1,728 bp sequence containing the cassava granule-bound starch synthase (GBSSI) promoter was isolated. The sequence proved to contain light- and sugar-responsive cis elements. Part of this sequence (1,167 bp) was cloned into binary vectors to drive expression of the firefly luciferase gene. Cassava cultivar Adira 4 was transformed with this construct or a control construct in which the luciferase gene was cloned behind the 35S promoter. Luciferase activity was measured in leaves, stems, roots and tuberous roots. As expected, the 35S promoter induced luciferase activity in all organs at similar levels, whereas the GBSSI promoter showed very low expression in leaves, stems and roots, but very high expression in tuberous roots. These results show that the cassava GBSSI promoter is an excellent candidate to achieve tuberous root-specific expression in cassava.

  6. Etiology and Epidemiological Conditions Promoting Fusarium Root Rot in Sweetpotato.

    PubMed

    Scruggs, A C; Quesada-Ocampo, L M

    2016-08-01

    Sweetpotato production in the United States is limited by several postharvest diseases, and one of the most common is Fusarium root rot. Although Fusarium solani is believed to be the primary causal agent of disease, numerous other Fusarium spp. have been reported to infect sweetpotato. However, the diversity of Fusarium spp. infecting sweetpotato in North Carolina is unknown. In addition, the lack of labeled and effective fungicides for control of Fusarium root rot in sweetpotato creates the need for integrated strategies to control disease. Nonetheless, epidemiological factors that promote Fusarium root rot in sweetpotato remain unexplored. A survey of Fusarium spp. infecting sweetpotato in North Carolina identified six species contributing to disease, with F. solani as the primary causal agent. The effects of storage temperature (13, 18, 23, 29, and 35°C), relative humidity (80, 90, and 100%), and initial inoculum level (3-, 5-, and 7-mm-diameter mycelia plug) were examined for progression of Fusarium root rot caused by F. solani and F. proliferatum on 'Covington' sweetpotato. Fusarium root rot was significantly reduced (P < 0.05) at lower temperatures (13°C), low relative humidity levels (80%), and low initial inoculum levels for both pathogens. Sporulation of F. proliferatum was also reduced under the same conditions. Qualitative mycotoxin analysis of roots infected with one of five Fusarium spp. revealed the production of fumonisin B1 by F. proliferatum when infecting sweetpotato. This study is a step toward characterizing the etiology and epidemiology of Fusarium root rot in sweetpotato, which allows for improved disease management recommendations to limit postharvest losses to this disease.

  7. Cassava root diet induces low pyruvate levels.

    PubMed

    Golay, Van K

    2010-01-01

    The high cyanogenic-glucoside carbohydrate of the cassava root (Manihot esculenta) has special properties that make it an ideal therapeutic food for lowering nicotinamide adenine dinucleotide reduced form (NADH) and inducing Sirtuin (Sirt) gene overexpression when eaten in an exclusive mono-food diet regime. The author, using himself as the sole test subject, repeatedly induced low pyruvate levels (reflective of NADH levels) after being on the diet for 1-2 weeks at a time. The possible influences of exclusive cassava dieting on redox control and Sirtuin activation will be discussed.

  8. Influence of Rhizoctonia-Bacterial root rot complex on storability of sugar beet

    USDA-ARS?s Scientific Manuscript database

    The root rot complex, caused by Rhizoctonia solani and Leuconostoc mesenteroides, can lead to yield loss in the field but may also lead to problems with sucrose loss in storage. Thus, studies were conducted to investigate if placing sugar beet roots suffering from root rot together with healthy roo...

  9. Beauveria bassiana and Metarhizium anisopliae endophytically colonize cassava roots following soil drench inoculation

    PubMed Central

    Greenfield, Melinda; Gómez-Jiménez, María I.; Ortiz, Viviana; Vega, Fernando E.; Kramer, Matthew; Parsa, Soroush

    2016-01-01

    We investigated the fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae to determine if endophytic colonization could be achieved in cassava. An inoculation method based on drenching the soil around cassava stem cuttings using conidial suspensions resulted in endophytic colonization of cassava roots by both entomopathogens, though neither was found in the leaves or stems of the treated cassava plants. Both fungal entomopathogens were detected more often in the proximal end of the root than in the distal end. Colonization levels of B. bassiana were higher when plants were sampled at 7–9 days post-inoculation (84%) compared to 47–49 days post-inoculation (40%). In contrast, the colonization levels of M. anisopliae remained constant from 7–9 days post-inoculation (80%) to 47–49 days post-inoculation (80%), which suggests M. anisopliae is better able to persist in the soil, or as an endophyte in cassava roots over time. Differences in colonization success and plant growth were found among the fungal entomopathogen treatments. PMID:27103778

  10. Laminated root rot in western North America.

    Treesearch

    Walter G. Thies; Rona N. Sturrock

    1995-01-01

    Laminated root rot, caused by Phellinus weirii (Murr.) Gilb., is a serious root disease affecting Douglas-fir and other commercially important species of conifers in northwestern North America. This report gives an overview of the dis-ease as it occurs in the Pacific Northwest in Canada and the United States. Information on recognizing crown...

  11. Comparison of Pratylenchus penetrans Infection and Maladera castanea Feeding on Strawberry Root Rot

    PubMed Central

    LaMondia, J. A.; Cowles, R. S.

    2005-01-01

    The interaction of lesion nematodes, black root rot disease caused by Rhizoctonia fragariae, and root damage caused by feeding of the scarab larva, Maladera castanea, was determined in greenhouse studies. Averaged over all experiments after 12 weeks, root weight was reduced 13% by R. fragariae and 20% by M. castanea. The percentage of the root system affected by root rot was increased by inoculation with either R. fragariae (35% more disease) or P. penetrans (50% more disease) but was unaffected by M. castanea. Rhizoctonia fragariae was isolated from 9.2% of the root segments from plants not inoculated with R. fragariae. The percentage of R. fragariae-infected root segments was increased 3.6-fold by inoculation with R. fragariae on rye seeds. The presence of P. penetrans also increased R. fragariae root infection. The type of injury to root systems was important in determining whether roots were invaded by R. fragariae and increased the severity of black root rot. Pratylenchus penetrans increased R. fragariae infection and the severity of black root rot. Traumatic cutting action by Asiatic garden beetle did not increase root infection or root disease by R. fragariae. Both insects and diseases need to be managed to extend the productive life of perennial strawberry plantings. PMID:19262852

  12. Interaction of Pratylenchus penetrans and Rhizoctonia fragariae in Strawberry Black Root Rot

    PubMed Central

    LaMondia, J. A.

    2003-01-01

    A split-root technique was used to examine the interaction between Pratylenchus penetrans and the cortical root-rotting pathogen Rhizoctonia fragariae in strawberry black root rot. Plants inoculated with both pathogens on the same half of a split-root crown had greater levels of root rot than plants inoculated separately or with either pathogen alone. Isolation of R. fragariae from field-grown roots differed with root type and time of sampling. Fungal infection of structural roots was low until fruiting, whereas perennial root colonization was high. Isolation of R. fragariae from feeder roots was variable, but was greater from feeder roots on perennial than from structural roots. Isolation of the fungus was greater from structural roots with nematode lesions than from non-symptomatic roots. Rhizoctonia fragariae was a common resident on the sloughed cortex of healthy perennial roots. From this source, the fungus may infect additional roots. The direct effects of lesion nematode feeding and movement are cortical cell damage and death. Indirect effects include discoloration of the endodermis and early polyderm formation. Perhaps weakened or dying cells caused directly or indirectly by P. penetrans are more susceptible to R. fragariae, leading to increased disease. PMID:19265969

  13. Evaluation of Sentinel-2A satellite imagery for mapping cotton root rot

    USDA-ARS?s Scientific Manuscript database

    Cotton (Gossypium hirsutum L.) is an economically important crop that is highly susceptible to cotton root rot. Remote sensing technology provides a useful and effective means for detecting and mapping cotton root rot infestations in cotton fields. This research assessed the potential of 10-m Sentin...

  14. Effects of Meloidogyne incognita on Growth and Storage-Root Formation of Cassava (Manihot esculenta)

    PubMed Central

    Makumbi-Kidza, N. N.; Speijer, P. R.; Sikora, R. A.

    2000-01-01

    Two-node cuttings of cassava cultivar SS4 were inoculated with 1,000 infective juveniles of Meloidogyne incognita at 1, 14, 40, 70, 88, and 127 days after planting (DAP). Plant growth and root damage were assessed at 150 DAP. Meloidogyne incognita significantly reduced the number of storageroots formed in plants inoculated at 14, 40, 70, and 88 DAP and the total weight of storage-roots in plants inoculated at 1, 14, 40, 70, and 88 DAP, compared to uninoculated plants. Individual storage-root weight and plant height were not affected by M. incognita. Storage-root formation in cassava is initiated when plants are 1 to 2 months old. The results of this experiment indicate that, at this time, young cassava plants are most prone to root-knot nematode damage in terms of storage-root formation. The production loss caused by M. incognita to young SS4 plants was due to a reduction of storage-root number rather than a reduction in individual storage-root weight. PMID:19270997

  15. Pre-Breeding for root rot resistance using root morphology traits

    USDA-ARS?s Scientific Manuscript database

    Root rot caused by the fungal pathogen Rhizoctonia solani can be a major yield-limiting disease in minimal tillage or direct-seeded cereal production systems. Reduced tillage greatly influences the plant residue retained on the soil surfaces. This retained residue (green bridge) provides increased d...

  16. Nonchemical, cultural management strategies to suppress phytophthora root rot in northern highbush blueberry

    USDA-ARS?s Scientific Manuscript database

    Phytophthora cinnamomi causes root rot of highbush blueberry and decreases plant growth, yield, and profitability for growers. Fungicides can suppress root rot, but cannot be used in certified organic production systems and fungicide resistance may develop. Alternative, non-chemical, cultural manag...

  17. Experimental Sugar Beet Cultivars Evaluated for Resistance Bacterial Root Rot in Idaho, 2008

    USDA-ARS?s Scientific Manuscript database

    Bacterial root rot of sugar beet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, a study was conducted to identify resistan...

  18. Overexpression of hydroxynitrile lyase in cassava roots elevates protein and free amino acids while reducing residual cyanogen levels.

    PubMed

    Narayanan, Narayanan N; Ihemere, Uzoma; Ellery, Claire; Sayre, Richard T

    2011-01-01

    Cassava is the major source of calories for more than 250 million Sub-Saharan Africans, however, it has the lowest protein-to-energy ratio of any major staple food crop in the world. A cassava-based diet provides less than 30% of the minimum daily requirement for protein. Moreover, both leaves and roots contain potentially toxic levels of cyanogenic glucosides. The major cyanogen in cassava is linamarin which is stored in the vacuole. Upon tissue disruption linamarin is deglycosylated by the apolplastic enzyme, linamarase, producing acetone cyanohydrin. Acetone cyanohydrin can spontaneously decompose at pHs >5.0 or temperatures >35°C, or is enzymatically broken down by hydroxynitrile lyase (HNL) to produce acetone and free cyanide which is then volatilized. Unlike leaves, cassava roots have little HNL activity. The lack of HNL activity in roots is associated with the accumulation of potentially toxic levels of acetone cyanohydrin in poorly processed roots. We hypothesized that the over-expression of HNL in cassava roots under the control of a root-specific, patatin promoter would not only accelerate cyanogenesis during food processing, resulting in a safer food product, but lead to increased root protein levels since HNL is sequestered in the cell wall. Transgenic lines expressing a patatin-driven HNL gene construct exhibited a 2-20 fold increase in relative HNL mRNA levels in roots when compared with wild type resulting in a threefold increase in total root protein in 7 month old plants. After food processing, HNL overexpressing lines had substantially reduced acetone cyanohydrin and cyanide levels in roots relative to wild-type roots. Furthermore, steady state linamarin levels in intact tissues were reduced by 80% in transgenic cassava roots. These results suggest that enhanced linamarin metabolism contributed to the elevated root protein levels.

  19. Expression profiling of cassava storage roots reveals an active process of glycolysis/gluconeogenesis.

    PubMed

    Yang, Jun; An, Dong; Zhang, Peng

    2011-03-01

    Mechanisms related to the development of cassava storage roots and starch accumulation remain largely unknown. To evaluate genome-wide expression patterns during tuberization, a 60 mer oligonucleotide microarray representing 20 840 cassava genes was designed to identify differentially expressed transcripts in fibrous roots, developing storage roots and mature storage roots. Using a random variance model and the traditional twofold change method for statistical analysis, 912 and 3 386 upregulated and downregulated genes related to the three developmental phases were identified. Among 25 significantly changed pathways identified, glycolysis/gluconeogenesis was the most evident one. Rate-limiting enzymes were identified from each individual pathway, for example, enolase, L-lactate dehydrogenase and aldehyde dehydrogenase for glycolysis/gluconeogenesis, and ADP-glucose pyrophosphorylase, starch branching enzyme and glucan phosphorylase for sucrose and starch metabolism. This study revealed that dynamic changes in at least 16% of the total transcripts, including transcription factors, oxidoreductases/transferases/hydrolases, hormone-related genes, and effectors of homeostasis. The reliability of these differentially expressed genes was verified by quantitative real-time reverse transcription-polymerase chain reaction. These studies should facilitate our understanding of the storage root formation and cassava improvement. © 2011 Institute of Botany, Chinese Academy of Sciences.

  20. Ground penetrating radar: a case study for estimating root bulking rate in cassava (Manihot esculenta Crantz).

    PubMed

    Delgado, Alfredo; Hays, Dirk B; Bruton, Richard K; Ceballos, Hernán; Novo, Alexandre; Boi, Enrico; Selvaraj, Michael Gomez

    2017-01-01

    Understanding root traits is a necessary research front for selection of favorable genotypes or cultivation practices. Root and tuber crops having most of their economic potential stored below ground are favorable candidates for such studies. The ability to image and quantify subsurface root structure would allow breeders to classify root traits for rapid selection and allow agronomist the ability to derive effective cultivation practices. In spite of the huge role of Cassava ( Manihot esculenta Crantz), for food security and industrial uses, little progress has been made in understanding the onset and rate of the root-bulking process and the factors that influence it. The objective of this research was to determine the capability of ground penetrating radar (GPR) to predict root-bulking rates through the detection of total root biomass during its growth cycle. Our research provides the first application of GPR for detecting below ground biomass in cassava. Through an empirical study, linear regressions were derived to model cassava bulking rates. The linear equations derived suggest that GPR is a suitable measure of root biomass ( r  = .79). The regression analysis developed accounts for 63% of the variability in cassava biomass below ground. When modeling is performed at the variety level, it is evident that the variety models for SM 1219-9 and TMS 60444 outperform the HMC-1 variety model (r 2  = .77, .63 and .51 respectively). Using current modeling methods, it is possible to predict below ground biomass and estimate root bulking rates for selection of early root bulking in cassava. Results of this approach suggested that the general model was over predicting at early growth stages but became more precise in later root development.

  1. Pathogenicity and genetic diversity of Fusarium oxysporum causing soybean root rot in northeast China

    USDA-ARS?s Scientific Manuscript database

    Soybean is an important edible legume cultivated around the world. However, soybean production is seriously impacted by the widespread occurrence of root rot disease. In this study, genetic diversity and pathogenicity of Fusarium oxysporum associated with root rot of soybean in Heilongjiang province...

  2. Provitamin A accumulation in cassava (Manihot esculenta) roots driven by a single nucleotide polymorphism in a phytoene synthase gene.

    PubMed

    Welsch, Ralf; Arango, Jacobo; Bär, Cornelia; Salazar, Bertha; Al-Babili, Salim; Beltrán, Jesús; Chavarriaga, Paul; Ceballos, Hernan; Tohme, Joe; Beyer, Peter

    2010-10-01

    Cassava (Manihot esculenta) is an important staple crop, especially in the arid tropics. Because roots of commercial cassava cultivars contain a limited amount of provitamin A carotenoids, both conventional breeding and genetic modification are being applied to increase their production and accumulation to fight vitamin A deficiency disorders. We show here that an allelic polymorphism in one of the two expressed phytoene synthase (PSY) genes is capable of enhancing the flux of carbon through carotenogenesis, thus leading to the accumulation of colored provitamin A carotenoids in storage roots. A single nucleotide polymorphism present only in yellow-rooted cultivars cosegregates with colored roots in a breeding pedigree. The resulting amino acid exchange in a highly conserved region of PSY provides increased catalytic activity in vitro and is able to increase carotenoid production in recombinant yeast and Escherichia coli cells. Consequently, cassava plants overexpressing a PSY transgene produce yellow-fleshed, high-carotenoid roots. This newly characterized PSY allele provides means to improve cassava provitamin A content in cassava roots through both breeding and genetic modification.

  3. Laminated Root Rot of Western Conifers

    Treesearch

    E.E. Nelson; N.E. Martin; R.E. Williams

    1981-01-01

    Laminated root rot is caused by the native fungus Phellinus weirii (Murr.) Gilb. It occurs throughout the Northwestern United States and in southern British Columbia, Canada. The disease has also been reported in Japan and Manchuria. In the United States, the pathogen is most destructive in pure Douglas-fir stands west of the crest of the Cascade Range in Washington...

  4. Extending cassava root shelf life via reduction of reactive oxygen species production.

    PubMed

    Zidenga, Tawanda; Leyva-Guerrero, Elisa; Moon, Hangsik; Siritunga, Dimuth; Sayre, Richard

    2012-08-01

    One of the major constraints facing the large-scale production of cassava (Manihot esculenta) roots is the rapid postharvest physiological deterioration (PPD) that occurs within 72 h following harvest. One of the earliest recognized biochemical events during the initiation of PPD is a rapid burst of reactive oxygen species (ROS) accumulation. We have investigated the source of this oxidative burst to identify possible strategies to limit its extent and to extend cassava root shelf life. We provide evidence for a causal link between cyanogenesis and the onset of the oxidative burst that triggers PPD. By measuring ROS accumulation in transgenic low-cyanogen plants with and without cyanide complementation, we show that PPD is cyanide dependent, presumably resulting from a cyanide-dependent inhibition of respiration. To reduce cyanide-dependent ROS production in cassava root mitochondria, we generated transgenic plants expressing a codon-optimized Arabidopsis (Arabidopsis thaliana) mitochondrial alternative oxidase gene (AOX1A). Unlike cytochrome c oxidase, AOX is cyanide insensitive. Transgenic plants overexpressing AOX exhibited over a 10-fold reduction in ROS accumulation compared with wild-type plants. The reduction in ROS accumulation was associated with a delayed onset of PPD by 14 to 21 d after harvest of greenhouse-grown plants. The delay in PPD in transgenic plants was also observed under field conditions, but with a root biomass yield loss in the highest AOX-expressing lines. These data reveal a mechanism for PPD in cassava based on cyanide-induced oxidative stress as well as PPD control strategies involving inhibition of ROS production or its sequestration.

  5. Rhizoctonia crown and root rot disease nursery

    USDA-ARS?s Scientific Manuscript database

    The BSDF cooperative CRR Eastern Evaluation Nursery Rhizoctonia crown and root rot Evaluation Nursery in 2016 was a randomized complete-block design with five replications in 15 feet long, one-row plots (20 in row spacing), at the Saginaw Valley Research and Education Center near Frankenmuth, MI. F...

  6. Isolation and partial characterization of a root-specific promoter for stacking multiple traits into cassava (Manihot esculenta CRANTZ).

    PubMed

    Gbadegesin, M A; Beeching, J R

    2011-06-07

    Cassava can be cultivated on impoverished soils with minimum inputs, and its storage roots are a staple food for millions in Africa. However, these roots are low in bioavailable nutrients and in protein content, contain cyanogenic glycosides, and suffer from a very short post-harvest shelf-life, and the plant is susceptible to viral and bacterial diseases prevalent in Africa. The demand for improvement of cassava with respect to these traits comes from both farmers and national agricultural institutions. Genetic improvement of cassava cultivars by molecular biology techniques requires the availability of appropriate genes, a system to introduce these genes into cassava, and the use of suitable gene promoters. Cassava root-specific promoter for auxin-repressed protein was isolated using the gene walking approach, starting with a cDNA sequence. In silico analysis of promoter sequences revealed putative cis-acting regulatory elements, including root-specific elements, which may be required for gene expression in vascular tissues. Research on the activities of this promoter is continuing, with the development of plant expression cassettes for transformation into major African elite lines and farmers' preferred cassava cultivars to enable testing of tissue-specific expression patterns in the field.

  7. Commercial Sugar Beet Cultivars Evaluated for Resistance to Bacterial Root Rot in Idaho, 2008

    USDA-ARS?s Scientific Manuscript database

    Bacterial root rot of sugar beet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, a study was conducted to identify resistan...

  8. Retention during processing and bioaccessibility of β-carotene in high β-carotene transgenic cassava root.

    PubMed

    Failla, Mark L; Chitchumroonchokchai, Chureeporn; Siritunga, Dimuth; De Moura, Fabiana F; Fregene, Martin; Manary, Mark J; Sayre, Richard T

    2012-04-18

    Cassava is a root crop that serves as a primary caloric source for many African communities despite its low content of β-carotene (βC). Carotenoid content of roots from wild type (WT) and three transgenic lines with high βC were compared after cooking and preparation of nonfermented and fermented flours according to traditional African methods. The various methods of processing all decreased βC content per gram dry weight regardless of genotype. The greatest loss of βC occurred during preparation of gari (dry fermentation followed by roasting) from WT and transgenic lines. The quantities of βC in cooked transgenic cassava root that partitioned into mixed micelles during in vitro digestion and transported into Caco-2 cells were significantly greater than those for identically processed WT root. These results suggest that transgenic high βC cassava will provide individuals with greater quantities of bioaccessible βC.

  9. Proteomic analysis of injured storage roots in cassava (Manihot esculenta Crantz) under postharvest physiological deterioration

    PubMed Central

    Qin, Yuling; Djabou, Astride Stéphanie Mouafi; An, Feifei; Li, Kaimian; Li, Zhaogui; Yang, Long; Wang, Xiaojing

    2017-01-01

    Postharvest physiological deterioration (PPD) is a global challenge in the improvement of cassava value chain. However, how to reduce cassava spoilage and reveal the mechanism of injured cassava storage roots in response to PPD were poorly understood. In the present study, we investigated the activities of antioxidant enzymes of cassava injured storage roots in PPD-susceptible (SC9) and PPD-tolerant (QZ1) genotypes at the time-points from 0h to 120h, and further analyzed their proteomic changes using two-dimensional electrophoresis (2-DE) in combination with MALDI-TOF-MS/MS. Ninety-nine differentially expressed proteins were identified from SC9 and QZ1 genotypes in the pairwise comparison of 24h/0h, 48h/0h, 72h/0h and 96h/0h. Of those proteins were associated with 13 biological functions, in which carbohydrate and energy metabolism related proteins were the biggest amount differential proteins in both genotypes, followed by chaperones, DNA and RNA metabolism, and defense system. We speculated that SOD in combination with CAT activities would be the first line of defense against PPD to support PPD-tolerant cassava varieties. The four hub proteins including CPN60B, LOS2, HSC70-1 and CPN20B, produced from the network of protein-protein interaction, will be the candidate key proteins linked with PPD. This study provides a new clue to improve cassava PPD-tolerant varieties and would be helpful to much better understand the molecular mechanism of PPD of cassava injured storage roots. PMID:28339481

  10. Proteomic analysis of injured storage roots in cassava (Manihot esculenta Crantz) under postharvest physiological deterioration.

    PubMed

    Qin, Yuling; Djabou, Astride Stéphanie Mouafi; An, Feifei; Li, Kaimian; Li, Zhaogui; Yang, Long; Wang, Xiaojing; Chen, Songbi

    2017-01-01

    Postharvest physiological deterioration (PPD) is a global challenge in the improvement of cassava value chain. However, how to reduce cassava spoilage and reveal the mechanism of injured cassava storage roots in response to PPD were poorly understood. In the present study, we investigated the activities of antioxidant enzymes of cassava injured storage roots in PPD-susceptible (SC9) and PPD-tolerant (QZ1) genotypes at the time-points from 0h to 120h, and further analyzed their proteomic changes using two-dimensional electrophoresis (2-DE) in combination with MALDI-TOF-MS/MS. Ninety-nine differentially expressed proteins were identified from SC9 and QZ1 genotypes in the pairwise comparison of 24h/0h, 48h/0h, 72h/0h and 96h/0h. Of those proteins were associated with 13 biological functions, in which carbohydrate and energy metabolism related proteins were the biggest amount differential proteins in both genotypes, followed by chaperones, DNA and RNA metabolism, and defense system. We speculated that SOD in combination with CAT activities would be the first line of defense against PPD to support PPD-tolerant cassava varieties. The four hub proteins including CPN60B, LOS2, HSC70-1 and CPN20B, produced from the network of protein-protein interaction, will be the candidate key proteins linked with PPD. This study provides a new clue to improve cassava PPD-tolerant varieties and would be helpful to much better understand the molecular mechanism of PPD of cassava injured storage roots.

  11. Mapping Fusarium solani and Aphanomyces euteiches root rot resistance and root architecture quantitative trait loci in common bean (Phaseolus vulgaris)

    USDA-ARS?s Scientific Manuscript database

    Root rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RIL mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean in th...

  12. Postharvet losses associated with Rhizoctonia crown and root rot of sugarbeet

    USDA-ARS?s Scientific Manuscript database

    As the prevalence of Rhizoctonia crown and root rot (RCRR) increases, more diseased sugarbeet (Beta vulgaris L.) roots are destined for storage piles. To investigate the effect of RCRR on storage properties, roots with similar symptoms were grouped and extractable sucrose, invert sugar, and respirat...

  13. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    PubMed

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-21

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement.

  14. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization

    PubMed Central

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  15. Provitamin A Accumulation in Cassava (Manihot esculenta) Roots Driven by a Single Nucleotide Polymorphism in a Phytoene Synthase Gene[W

    PubMed Central

    Welsch, Ralf; Arango, Jacobo; Bär, Cornelia; Salazar, Bertha; Al-Babili, Salim; Beltrán, Jesús; Chavarriaga, Paul; Ceballos, Hernan; Tohme, Joe; Beyer, Peter

    2010-01-01

    Cassava (Manihot esculenta) is an important staple crop, especially in the arid tropics. Because roots of commercial cassava cultivars contain a limited amount of provitamin A carotenoids, both conventional breeding and genetic modification are being applied to increase their production and accumulation to fight vitamin A deficiency disorders. We show here that an allelic polymorphism in one of the two expressed phytoene synthase (PSY) genes is capable of enhancing the flux of carbon through carotenogenesis, thus leading to the accumulation of colored provitamin A carotenoids in storage roots. A single nucleotide polymorphism present only in yellow-rooted cultivars cosegregates with colored roots in a breeding pedigree. The resulting amino acid exchange in a highly conserved region of PSY provides increased catalytic activity in vitro and is able to increase carotenoid production in recombinant yeast and Escherichia coli cells. Consequently, cassava plants overexpressing a PSY transgene produce yellow-fleshed, high-carotenoid roots. This newly characterized PSY allele provides means to improve cassava provitamin A content in cassava roots through both breeding and genetic modification. PMID:20889914

  16. Genome-wide analysis reveals phytohormone action during cassava storage root initiation.

    PubMed

    Sojikul, Punchapat; Saithong, Treenut; Kalapanulak, Saowalak; Pisuttinusart, Nuttapat; Limsirichaikul, Siripan; Tanaka, Maho; Utsumi, Yoshinori; Sakurai, Tetsuya; Seki, Motoaki; Narangajavana, Jarunya

    2015-08-01

    Development of storage roots is a process associated with a phase change from cell division and elongation to radial growth and accumulation of massive amounts of reserve substances such as starch. Knowledge of the regulation of cassava storage root formation has accumulated over time; however, gene regulation during the initiation and early stage of storage root development is still poorly understood. In this study, transcription profiling of fibrous, intermediate and storage roots at eight weeks old were investigated using a 60-mer-oligo microarray. Transcription and gene expression were found to be the key regulating processes during the transition stage from fibrous to intermediate roots, while homeostasis and signal transduction influenced regulation from intermediate roots to storage roots. Clustering analysis of significant genes and transcription factors (TF) indicated that a number of phytohormone-related TF were differentially expressed; therefore, phytohormone-related genes were assembled into a network of correlative nodes. We propose a model showing the relationship between KNOX1 and phytohormones during storage root initiation. Exogeneous treatment of phytohormones N (6) -benzylaminopurine and 1-Naphthaleneacetic acid were used to induce the storage root initiation stage and to investigate expression patterns of the genes involved in storage root initiation. The results support the hypothesis that phytohormones are acting in concert to regulate the onset of cassava storage root development. Moreover, MeAGL20 is a factor that might play an important role at the onset of storage root initiation when the root tip becomes swollen.

  17. Linamarase Expression in Cassava Cultivars with Roots of Low- and High-Cyanide Content1

    PubMed Central

    Santana, María Angélica; Vásquez, Valeria; Matehus, Juan; Aldao, Rafael Rangel

    2002-01-01

    This paper reports the expression and localization of linamarase in roots of two cassava (Manihot esculenta Crantz) cultivars of low and high cyanide. Two different patterns of linamarase activity were observed. In the low-cyanide type, young leaves displayed very high enzyme activity during the early plant growing stage (3 months), whereas in root peel, the activity increased progressively to reach a peak in 11-month-old plants. Conversely, in the high-cyanide cultivar (HCV), root peel linamarase activity decreased during the growth cycle, whereas in expanded leaves linamarase activity peaked in 11-month-old plants. The accumulation of linamarin showed a similar pattern in both cultivars, although a higher concentration was always found in the HCV. Linamarase was found mainly in laticifer cells of petioles and roots of both cultivars with no significant differences between them. At the subcellular level, there were sharp differences because linamarase was found mainly in the cell walls of the HCV, whereas in the low-cyanide cultivar, the enzyme was present in vacuoles and cell wall of laticifer cells. Reverse transcriptase-PCR on cassava tissues showed no expression of linamarase in cassava roots, thus, the transport of linamarase from shoots to roots through laticifers is proposed. PMID:12177481

  18. [Research on bacteria microecology in root rot rhizosphere soil of Coptis chinensis produced in Shizhu city].

    PubMed

    Song, Xu-Hong; Wang, Yu; Li, Long-Yun; Tan, Jun

    2017-04-01

    Illumina Hiseq 2500 high-throughput sequencing platform was used to study the bacteria richness and diversity, the soil enzyme activities, nutrients in unplanted soil, root-rot and healthy rhizophere soil of Coptis chinensis for deeply discussing the mechanism of the root-rot of C. chinensis. The high-throughput sequencing result showed that the artificial cultivation effected the bacteria community richness and diversity. The bacteria community richness in healthy and diseased rhizosphere soil showed significant lower than that of in unplanted soil (P<0.05) and declined bacteria diversity. The bacteria community richness in root-rot rhizosphere soil increased significantly than that of health and unplanted soil and the diversity was lower significant than that of unplanted soil (P<0.05). The results of soil nutrients and enzyme activities detected that the pH value, available phosphorus and urease activity decreased and the sucrase activity increased significantly (P<0.05). The content of organic carbon and alkaline hydrolysis nitrogen the catalase and urease activity in root rot soil samples was significantly lower than that of healthy soil samples (P<0.05). However, the contents of available phosphorus and available potassium were significantly in root-rot sample higher than that of healthy soil samples (P<0.05). Comprehensive analysis showed that the artificial cultivation declined the bacteria community richness and diversity. The bacteria community richness decreased significantly and the decreased diversity may be the cause of the root-rot. Meanwhile, the decrease of carbon and the catalase activity may be another cause of the root-rot in C. chinensis produced in Shizhu city, Chongqing province. Copyright© by the Chinese Pharmaceutical Association.

  19. Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance, hydrocyanide intake and haematological parameters of broiler chicks.

    PubMed

    Akapo, Abiola Olajetemi; Oso, Abimbola Oladele; Bamgbose, Adeyemi Mustapha; Sanwo, Kehinde A; Jegede, Adebayo Vincent; Sobayo, Richard Abayomi; Idowu, Olusegun Mark; Fan, Juexin; Li, Lili; Olorunsola, Rotimi A

    2014-10-01

    The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2 × 2 + 1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P < 0.01) final liveweight and weight gain, least (P < 0.05) hydrocyanide (HCN) intake and best (P < 0.05) feed-to-gain ratio. Chicks fed with control and diet containing 100 g/kg peeled cassava root meal (PCRM) had the least (P < 0.05) feed cost per weight gain. Chicks fed with diet containing 100 g/kg cassava root meal had higher (P < 0.05) final liveweight and weight gain and reduced (P < 0.05) HCN intake than chicks fed with diet containing 200 g/kg cassava root meal. Dietary inclusion of peeled cassava root meal (PCRM) for broiler chicks resulted in increased final liveweight (P < 0.05), weight gain (P < 0.01) and feed intake (P < 0.01) when compared with birds fed with diet containing unpeeled cassava root meal (UCRM). The least (P < 0.01) final liveweight and weight gain and worst (P < 0.05) feed-to-gain ratio were obtained with chicks fed with diet containing 200 g/kg UCRM. Increased dietary inclusion levels of cassava root resulted in significant increase (P < 0.05) in white blood cell (WBC) count, heterophil count and serum thiocyanate concentration. In comparison with chicks fed with diet containing UCRM, dietary inclusion of PCRM resulted in increased (P < 0.05) red blood cell (RBC) count and haemoglobin (Hb) concentration and reduced (P < 0.05) white blood cell (WBC) count and serum

  20. The retail market for fresh cassava root tubers in the European Union (EU): the case of Copenhagen, Denmark--a chemical food safety issue?

    PubMed

    Kolind-Hansen, Lotte; Brimer, Leon

    2010-01-30

    A number of retail shops in Copenhagen sell fresh cassava roots. Cassava roots contain the toxic cyanogenic glucoside linamarin. A survey was made of the shop characteristics, origin of the roots, buyers, shop owner's knowledge of toxicity levels, and actual toxicity levels. Shops selling fresh cassava were shown mostly to be owned by persons originating in the Middle East or Afghanistan, buyers were found to predominantly be of African origin, and sellers' knowledge concerning the potential toxicity was found to be very restricted. Seventy-six per cent of the roots purchased had a total cyanogenic potentials (CNp) above the 50 mg HCN equivalents kg(-1) dry weight (d.w.) proposed as acceptable by an EU working group. Two of 25 roots purchased had CNp higher than 340 mg HCN eq. kg(-1) d.w. The EU has previously made risk assessments concerning cassava and cyanogenic compounds. In the light of the conclusions drawn, the EU needs to make decisions about how to deal with the regulation and control of fresh cassava roots imported to the European food market. Also cassava root products and cassava leaves should be considered. (c) 2009 Society of Chemical Industry.

  1. Pre-breeding for root rot resistance using root morphology and shoot length.

    USDA-ARS?s Scientific Manuscript database

    Our goal is to identify new wheat varieties that display field resistance/tolerance to root rot diseases, such as those caused by Rhizoctonia and Pythium. We are tapping into the genetic diversity of ‘synthetic’ hexaploid wheats (genome composition AABBDD), which were generated at CIMMYT by artifici...

  2. Effects of boiling and frying on the bioaccessibility of beta-carotene in yellow-fleshed cassava roots (Manihot esculenta Crantz cv. BRS Jari).

    PubMed

    Gomes, Suellen; Torres, Alexandre Guedes; Godoy, Ronoel; Pacheco, Sidney; Carvalho, José; Nutti, Marília

    2013-03-01

    The effects of boiling and frying on the bioaccessibility of all-trans-beta-carotene in biofortified BRS Jari cassava roots have not been investigated, although these are conventional methods of cassava preparation. The aims of the present study were to investigate beta-carotene micellarization efficiency of yellow-fleshed BRS Jari cassava roots after boiling and frying, as an indicator of the bioaccessibility of this carotenoid, and to apply fluorescence microscopy to investigate beta-carotene in the emulsified fraction. Uncooked, boiled, and fried cassava roots were digested in vitro for the evaluation, by reversed-phase high-performance liquid chromatography (HPLC), of the efficiency of micellarization of all-trans-beta-carotene in BRS Jari cassava roots. Fluorescence microscopy of the micellar fraction was used to confirm the presence of beta-carotene in the emulsified fraction and to observe the structure of the microemulsion from the boiled and fried cassava samples. Fried cassava roots showed the highest (p < .05) micellarization efficiency for total carotenoids and all-trans-beta-carotene (14.1 +/- 2.25% and 14.37 +/- 2.44%, respectively), compared with boiled and raw samples. Fluorescence microscopy showed that after in vitro digestion there were no carotenoid crystals in the micellar fraction, but rather that this fraction presented a biphasic system compatible with emulsified carotenoids, which was consistent with the expected high bioavailability of beta-carotene in this fraction. Increased emulsification and bioaccessibility of beta-carotene from fried biofortified BRS Jari cassava roots compensates for chemical losses during preparation, indicating that this preparation is suitable for home use of BRS Jari cassava roots and might represent a relatively good food source of bioavailable provitamin A.

  3. Efficacy of management tools for control of Pythium root rot of Douglas fir seedlings, 2010

    USDA-ARS?s Scientific Manuscript database

    This study investigated the efficacy of management tools for control of Pythium root rot of Douglas fir seedlings. This effort was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rot of ornamental plants ca...

  4. Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root

    USDA-ARS?s Scientific Manuscript database

    Several groups have reported on massive accumulation of total carotenoids in cassava storage root (CSR). Naturally occurring color variation associated with carotenoid accumulation was observed in cassava (Manihot esculenta Crantz) storage root of landraces from Amazon. Here carotenoid profiles from...

  5. Iron Biofortification and Homeostasis in Transgenic Cassava Roots Expressing the Algal Iron Assimilatory Gene, FEA1

    PubMed Central

    Ihemere, Uzoma E.; Narayanan, Narayanan N.; Sayre, Richard T.

    2012-01-01

    We have engineered the tropical root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory gene, FEA1, in its storage roots with the objective of enhancing the root nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36 ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500 g meal. Significantly, the expression of the FEA1 gene in storage roots did not alter iron levels in leaves. Transgenic plants also had normal levels of zinc in leaves and roots consistent with the specific uptake of ferrous iron mediated by the FEA1 protein. Relative to wild-type plants, fibrous roots of FEA1 expressing plants had reduced Fe (III) chelate reductase activity consistent with the more efficient uptake of iron in the transgenic plants. We also show that multiple cassava genes involved in iron homeostasis have altered tissue-specific patterns of expression in leaves, stems, and roots of transgenic plants consistent with increased iron sink strength in transgenic roots. These results are discussed in terms of strategies for the iron biofortification of plants. PMID:22993514

  6. Fungicides reduce Rhododendron root rot and mortality caused by Phytophthora cinnamomi, but not by P. plurivora

    USDA-ARS?s Scientific Manuscript database

    Rhododendron root rot, caused by several Phytophthora species, can cause devastating losses in nursery-grown plants. Most research on chemical control of root rot has focused on Phytophthora cinnamomi. However, it is unknown whether treatments recommended for P. cinnamomi are also effective for othe...

  7. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

    PubMed

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

  8. First report of root rot of cowpea caused by Fusarium equiseti in Georgia in the United States

    USDA-ARS?s Scientific Manuscript database

    Root rot was observed on cowpea in Tift County, Georgia, in May of 2015. The disease occurred on approximately 10% of cowpea plants in 2 fields (2 ha). Symptoms appeared as sunken reddish brown lesions on roots and stems under the soil line, secondary roots became dark brown and rotted, and infected...

  9. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

    PubMed Central

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  10. Non-invasive monitoring of below ground cassava storage root bulking by ground penetrating radar technology

    NASA Astrophysics Data System (ADS)

    Ruiz Vera, U. M.; Larson, T. H.; Mwakanyamale, K. E.; Grennan, A. K.; Souza, A. P.; Ort, D. R.; Balikian, R. J.

    2017-12-01

    Agriculture needs a new technological revolution to be able to meet the food demands, to overcome weather and natural hazards events, and to monitor better crop productivity. Advanced technologies used in other fields have recently been applied in agriculture. Thus, imagine instrumentation has been applied to phenotype above-ground biomass and predict yield. However, the capability to monitor belowground biomass is still limited. There are some existing technologies available, for example the ground penetrating radar (GPR) which has been used widely in the area of geology and civil engineering to detect different kind of formations under the ground without the disruption of the soil. GPR technology has been used also to monitor tree roots but as yet not crop roots. Some limitation are that the GPR cannot discern roots smaller than 2 cm in diameter, but it make it feasible for application in tuber crops like Cassava since harvest diameter is greater than 4 cm. The objective of this research is to test the availability to use GPR technology to monitor the growth of cassava roots by testing this technique in the greenhouse and in the field. So far, results from the greenhouse suggest that GPR can detect mature roots of cassava and this data could be used to predict biomass.

  11. Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root.

    PubMed

    Carvalho, Luiz Jcb; Agustini, Marco Av; Anderson, James V; Vieira, Eduardo A; de Souza, Claudia Rb; Chen, Songbi; Schaal, Barbara A; Silva, Joseane P

    2016-06-10

    Cassava (Manihot esculenta Crantz) storage root provides a staple food source for millions of people worldwide. Increasing the carotenoid content in storage root of cassava could provide improved nutritional and health benefits. Because carotenoid accumulation has been associated with storage root color, this study characterized carotenoid profiles, and abundance of key transcripts associated with carotenoid biosynthesis, from 23 landraces of cassava storage root ranging in color from white-to-yellow-to-pink. This study provides important information to plant breeding programs aimed at improving cassava storage root nutritional quality. Among the 23 landraces, five carotenoid types were detected in storage root with white color, while carotenoid types ranged from 1 to 21 in storage root with pink and yellow color. The majority of storage root in these landraces ranged in color from pale-to-intense yellow. In this color group, total β-carotene, containing all-E-, 9-Z-, and 13-Z-β-carotene isomers, was the major carotenoid type detected, varying from 26.13 to 76.72 %. Although no α-carotene was observed, variable amounts of a α-ring derived xanthophyll, lutein, was detected; with greater accumulation of α-ring xanthophylls than of β-ring xanthophyll. Lycopene was detected in a landrace (Cas51) with pink color storage root, but it was not detected in storage root with yellow color. Based on microarray and qRT-PCR analyses, abundance of transcripts coding for enzymes involved in carotenoid biosynthesis were consistent with carotenoid composition determined by contrasting HPLC-Diode Array profiles from storage root of landraces IAC12, Cas64, and Cas51. Abundance of transcripts encoding for proteins regulating plastid division were also consistent with the observed differences in total β-carotene accumulation. Among the 23 cassava landraces with varying storage root color and diverse carotenoid types and profiles, landrace Cas51 (pink color storage root) had low

  12. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt

    PubMed Central

    Hassan, Naglaa; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt. PMID:24808737

  13. Cyanogenesis in Cassava1

    PubMed Central

    White, Wanda L.B.; Arias-Garzon, Diana I.; McMahon, Jennifer M.; Sayre, Richard T.

    1998-01-01

    In the cyanogenic crop cassava (Manihot esculenta, Crantz), the final step in cyanide production is the conversion of acetone cyanohydrin, the deglycosylation product of linamarin, to cyanide plus acetone. This process occurs spontaneously at pH greater than 5.0 or enzymatically and is catalyzed by hydroxynitrile lyase (HNL). Recently, it has been demonstrated that acetone cyanohydrin is present in poorly processed cassava root food products. Since it has generally been assumed that HNL is present in all cassava tissues, we reinvestigated the enzymatic properties and tissue-specific distribution of HNL in cassava. We report the development of a rapid two-step purification protocol for cassava HNL, which yields an enzyme that is catalytically more efficient than previously reported (Hughes, J., Carvalho, F., and Hughes, M. [1994] Arch Biochem Biophys 311: 496–502). Analyses of the distribution of HNL activity and protein indicate that the accumulation of acetone cyanohydrin in roots is due to the absence of HNL, not to inhibition of the enzyme. Furthermore, the absence of HNL in roots and stems is associated with very low steady-state HNL transcript levels. It is proposed that the lack of HNL in cassava roots accounts for the high acetone cyanohydrin levels in poorly processed cassava food products. PMID:9536038

  14. First report of lily root rot caused by Thantephorus cucumeris AG 2-1 in the United States

    USDA-ARS?s Scientific Manuscript database

    A disease survey was undertaken in April, 2016 to profile the soilborne fungal pathogens causing root rot and lesions on lily (Lilium longiflorum) cv. Nellie White in Brookings, Oregon, Curry County. Diseased root samples were either blackened or rotted. Several fungal isolates were cultured from in...

  15. The cassava (Manihot esculenta Crantz) root proteome: protein identification and differential expression.

    PubMed

    Sheffield, Jeanne; Taylor, Nigel; Fauquet, Claude; Chen, Sixue

    2006-03-01

    Using high-resolution 2-DE, we resolved proteins extracted from fibrous and tuberous root tissues of 3-month-old cassava plants. Gel image analysis revealed an average of 1467 electrophoretically resolved spots on the fibrous gels and 1595 spots on the tuberous gels in pH 3-10 range. Protein spots from both sets of gels were digested with trypsin. The digests were subjected to nanoelectrospray quadrupole TOF tandem mass analysis. Currently, we have obtained 299 protein identifications for 292 gel spots corresponding to 237 proteins. The proteins span various functional categories from energy, primary and secondary metabolism, disease and defense, destination and storage, transport, signal transduction, protein synthesis, cell structure, and transcription to cell growth and division. Gel image analysis has shown unique, as well as up- and down-regulated proteins, present in the tuberous and the fibrous tissues. Quantitative and qualitative analysis of the cassava root proteome is an important step towards further characterization of differentially expressed proteins and the elucidation of the mechanisms underlying the development and biological functions of the two types of roots.

  16. RNAi inhibition of feruloyl CoA 6'-hydroxylase reduces scopoletin biosynthesis and post-harvest physiological deterioration in cassava (Manihot esculenta Crantz) storage roots.

    PubMed

    Liu, Shi; Zainuddin, Ima M; Vanderschuren, Herve; Doughty, James; Beeching, John R

    2017-05-01

    Cassava (Manihot esculenta Crantz) is a major world crop, whose storage roots provide food for over 800 million throughout the humid tropics. Despite many advantages as a crop, the development of cassava is seriously constrained by the rapid post-harvest physiological deterioration (PPD) of its roots that occurs within 24-72 h of harvest, rendering the roots unpalatable and unmarketable. PPD limits cassava's marketing possibilities in countries that are undergoing increased development and urbanisation due to growing distances between farms and consumers. The inevitable wounding of the roots caused by harvesting triggers an oxidative burst that spreads throughout the cassava root, together with the accumulation of secondary metabolites including phenolic compounds, of which the coumarin scopoletin (7-hydroxy-6-methoxy-2H-1-benzopyran-2-one) is the most abundant. Scopoletin oxidation yields a blue-black colour, which suggests its involvement in the discoloration observed during PPD. Feruloyl CoA 6'-hydroxylase is a controlling enzyme in the biosynthesis of scopoletin. The cassava genome contains a seven membered family of feruloyl CoA 6'-hydroxylase genes, four of which are expressed in the storage root and, of these, three were capable of functionally complementing Arabidopsis T-DNA insertion mutants in this gene. A RNA interference construct, designed to a highly conserved region of these genes, was used to transform cassava, where it significantly reduced feruloyl CoA 6'-hydroxylase gene expression, scopoletin accumulation and PPD symptom development. Collectively, our results provide evidence that scopoletin plays a major functional role in the development of PPD symptoms, rather than merely paralleling symptom development in the cassava storage root.

  17. Toward better understanding of postharvest deterioration: biochemical changes in stored cassava (Manihot esculenta Crantz) roots.

    PubMed

    Uarrota, Virgílio Gavicho; Nunes, Eduardo da Costa; Peruch, Luiz Augusto Martins; Neubert, Enilto de Oliveira; Coelho, Bianca; Moresco, Rodolfo; Domínguez, Moralba Garcia; Sánchez, Teresa; Meléndez, Jorge Luis Luna; Dufour, Dominique; Ceballos, Hernan; Becerra Lopez-Lavalle, Luis Augusto; Hershey, Clair; Rocha, Miguel; Maraschin, Marcelo

    2016-05-01

    Food losses can occur during production, postharvest, and processing stages in the supply chain. With the onset of worldwide food shortages, interest in reducing postharvest losses in cassava has been increasing. In this research, the main goal was to evaluate biochemical changes and identify the metabolites involved in the deterioration of cassava roots. We found that high levels of ascorbic acid (AsA), polyphenol oxidase (PPO), dry matter, and proteins are correlated with overall lower rates of deterioration. On the other hand, soluble sugars such as glucose and fructose, as well as organic acids, mainly, succinic acid, seem to be upregulated during storage and may play a role in the deterioration of cassava roots. Cultivar Branco (BRA) was most resilient to postharvest physiological deterioration (PPD), while Oriental (ORI) was the most susceptible. Our findings suggest that PPO, AsA, and proteins may play a distinct role in PPD delay.

  18. Effects of different rates of drying cassava root on its toxicity to broiler chicks.

    PubMed

    Panigrahi, S; Rickard, J; O'Brien, G M; Gay, C

    1992-12-01

    1. The effects of drying cassava root at different rates on its composition and toxicity to broiler chicks were examined. Unpeeled roots from a high-cyanide cultivar of cassava were chipped and dried at 25 degrees C to a moisture content of below 100 g/kg over 24 h for fast-dried meal (FD) or 72 h for slow-dried meal (SD). The meals were incorporated at 250 and 500 g/kg into semi-synthetic diets which were fed to day-old broiler chicks as mash or pellets in separate experiments. 2. The two drying rates produced meals with similar concentrations of polyphenols, but different concentrations of cyanogens, the latter being 38 and 482 mg total cyanide/kg for SD and FD, respectively. The linamarin, acetonecyanohydrin or total cyanide content measurements of pelleted diets were highly correlated. 3. Growth rates of chicks fed on SD-based diets were significantly higher than those of chicks fed on FD-based diets. Compared with a control diet, weight gain of chicks fed on the 500 g FD/kg diet (containing 258 mg total cyanide/kg) was 77% lower, although performance also appeared to be reduced at 142 mg total cyanide/kg. 4. The ratio of water:food intake of chicks was higher in FD than in SD groups, and this was reflected in the high water content of excreta. There was increased bile excretion, the chloretic effect increasing with the cyanogen content of diet. Pancreas weights were lower in FD than in SD groups in experiment 1 (mash diets), but not in experiment 2 (pelleted diets), while there was a significant interaction between drying method and cassava inclusion rate on liver weight in experiment 2, but not in experiment 1. There were no effects on the mortality rate. 5. Pelleting of diets generated high temperatures, but did not significantly alter the cyanogen concentration or the growth of the chicks. 6. Thus, slower rates of drying cassava roots produce meals with lower cyanogen concentration that are, consequently, less toxic to broiler chicks. Cassava root meal of

  19. Monitoring cotton root rot by synthetic Sentinel-2 NDVI time series using improved spatial and temporal data fusion

    USDA-ARS?s Scientific Manuscript database

    Airborne imagery has been successfully used for mapping cotton root rot within cotton fields toward the end of the growing season. To better understand the progression of cotton root rot within the season, time series monitoring is required. In this study, an improved spatial and temporal data fusio...

  20. Extending Cassava Root Shelf Life via Reduction of Reactive Oxygen Species Production1[C][W][OA

    PubMed Central

    Zidenga, Tawanda; Leyva-Guerrero, Elisa; Moon, Hangsik; Siritunga, Dimuth; Sayre, Richard

    2012-01-01

    One of the major constraints facing the large-scale production of cassava (Manihot esculenta) roots is the rapid postharvest physiological deterioration (PPD) that occurs within 72 h following harvest. One of the earliest recognized biochemical events during the initiation of PPD is a rapid burst of reactive oxygen species (ROS) accumulation. We have investigated the source of this oxidative burst to identify possible strategies to limit its extent and to extend cassava root shelf life. We provide evidence for a causal link between cyanogenesis and the onset of the oxidative burst that triggers PPD. By measuring ROS accumulation in transgenic low-cyanogen plants with and without cyanide complementation, we show that PPD is cyanide dependent, presumably resulting from a cyanide-dependent inhibition of respiration. To reduce cyanide-dependent ROS production in cassava root mitochondria, we generated transgenic plants expressing a codon-optimized Arabidopsis (Arabidopsis thaliana) mitochondrial alternative oxidase gene (AOX1A). Unlike cytochrome c oxidase, AOX is cyanide insensitive. Transgenic plants overexpressing AOX exhibited over a 10-fold reduction in ROS accumulation compared with wild-type plants. The reduction in ROS accumulation was associated with a delayed onset of PPD by 14 to 21 d after harvest of greenhouse-grown plants. The delay in PPD in transgenic plants was also observed under field conditions, but with a root biomass yield loss in the highest AOX-expressing lines. These data reveal a mechanism for PPD in cassava based on cyanide-induced oxidative stress as well as PPD control strategies involving inhibition of ROS production or its sequestration. PMID:22711743

  1. iTRAQ-based analysis of changes in the cassava root proteome reveals pathways associated with post-harvest physiological deterioration.

    PubMed

    Owiti, Judith; Grossmann, Jonas; Gehrig, Peter; Dessimoz, Christophe; Laloi, Christophe; Hansen, Maria Benn; Gruissem, Wilhelm; Vanderschuren, Hervé

    2011-07-01

    The short storage life of harvested cassava roots is an important constraint that limits the full potential of cassava as a commercial food crop in developing countries. We investigated the molecular changes during physiological deterioration of cassava root after harvesting using isobaric tags for relative and absolute quantification (iTRAQ) of proteins in soluble and non-soluble fractions prepared during a 96 h post-harvest time course. Combining bioinformatic approaches to reduce information redundancy for unsequenced or partially sequenced plant species, we established a comprehensive proteome map of the cassava root and identified quantitatively regulated proteins. Up-regulation of several key proteins confirmed that physiological deterioration of cassava root after harvesting is an active process, with 67 and 170 proteins, respectively, being up-regulated early and later after harvesting. This included regulated proteins that had not previously been associated with physiological deterioration after harvesting, such as linamarase, glutamic acid-rich protein, hydroxycinnamoyl transferase, glycine-rich RNA binding protein, β-1,3-glucanase, pectin methylesterase, maturase K, dehydroascorbate reductase, allene oxide cyclase, and proteins involved in signal pathways. To confirm the regulation of these proteins, activity assays were performed for selected enzymes. Together, our results show that physiological deterioration after harvesting is a highly regulated complex process involving proteins that are potential candidates for biotechnology approaches to reduce such deterioration. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  2. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits

    PubMed Central

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p < 0.01), with waxy clones having a 0.8% lower content than their wild type counterparts. There was no effect of starch type on fresh root yield (FRY), adjusted FRY and harvest index. It is not clear if lower DMC is a pleiotropic effect of the waxy starch mutation or else the result of linked genes introgressed along with the mutation. It is expected that commercial waxy cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops. PMID:27242813

  3. Iron and protein biofortification of cassava: lessons learned.

    PubMed

    Leyva-Guerrero, Elisa; Narayanan, Narayanan N; Ihemere, Uzoma; Sayre, Richard T

    2012-04-01

    Over two hundred and fifty million Africans rely on the starchy root crop cassava (Manihot esculenta) as their primary source of calories. Cassava roots, however, have the lowest protein:energy ratio of all the world's major staple crops. Furthermore, a typical cassava-based diet provides less than 10-20% of the required amounts of iron, zinc, vitamin A and vitamin E. The BioCassava Plus program employed modern biotechnologies to improve the health of Africans through development and delivery of novel cassava germplasm with increased nutrient levels. Here we describe the development of molecular strategies and their outcomes to meet minimum daily allowances for protein and iron in cassava based diets. We demonstrate that cyanogens play a central role in cassava nitrogen metabolism and that strategies employed to increase root protein levels result in reduced cyanogen levels in roots. We also demonstrate that enhancing root iron uptake has an impact on the expression of genes that regulate iron homeostasis in multiple tissues. These observations demonstrate the complex metabolic interactions involved in enhancing targeted nutrient levels in plants and identify potential new strategies for further enhancing nutrient levels in cassava. Published by Elsevier Ltd.

  4. Spread of Fomes annosus root rot in thinned shortleaf pine plantations

    Treesearch

    Frederick H. Berry

    1968-01-01

    Plots were established in thinned shortleaf pine plantations in Missouri to determine the rate of spread of Fomes annosus root rot over a 5-year period. On these plots mortality from F. annosus was about 5 trees per acre per year.

  5. Root rots of common and tepary beans in Puerto Rico

    USDA-ARS?s Scientific Manuscript database

    Root rots are a disease complex affecting common bean and can be severe in bean growing areas in the tropics and subtropics. The presence of several pathogens makes it difficult to breed for resistance because of the synergistic effect of the pathogens in the host and the interaction of soil factors...

  6. A novel penicillium sp. causes rot in stored sugar beet roots in Idaho

    USDA-ARS?s Scientific Manuscript database

    Penicillium vulpinum along with a number of other fungi can lead to the rot of stored sugar beet roots. However, Penicillium isolates associated with necrotic lesions on roots from a recent sugar beet storage study were determined to be different from P. vulpinum and other recognized Penicillium sp...

  7. Comparative Proteome Analysis of the Tuberous Roots of Six Cassava (Manihot esculenta) Varieties Reveals Proteins Related to Phenotypic Traits.

    PubMed

    Schmitz, Gabriela Justamante Händel; de Magalhães Andrade, Jonathan; Valle, Teresa Losada; Labate, Carlos Alberto; do Nascimento, João Roberto Oliveira

    2016-04-27

    Cassava (Manihot esculenta Crantz) is a staple food and an important source of starch, and the attributes of its tuberous root largely depend on the variety. The proteome of cassava has been investigated; however, to date, no study has focused on varieties that reveal the molecular basis of phenotypical characteristics. Therefore, we aimed to compare the proteome of the tuberous roots of six cassava varieties that differed in carbohydrates, carotenoids, and resistance to diseases, among other attributes. Two-dimensional gels showed 146 differential spots between the varieties, and the functional roles of some differential proteins were correlated to phenotypic characteristics of the varieties, such as the amount of carbohydrates or carotenoids and the resistance to biotic or abiotic stresses. The results obtained here highlight elements that might help to direct the improvement of new cultivars of cassava, which is an economically and socially relevant crop worldwide.

  8. Influence of sugarbeet tillage systems on rhizoctonia-bacterial root rot complex

    USDA-ARS?s Scientific Manuscript database

    The Rhizoctonia-bacterial root rot complex on sugarbeet caused by Rhizoctonia solani and Leuconostoc mesenteroides can cause significant yield losses. To investigate the impact of different tillage systems on this complex, field studies were conducted from 2009 to 2011. Split blocks with conventio...

  9. Aphanomyces root rot of alfalfa: widespread distribution of race 2

    USDA-ARS?s Scientific Manuscript database

    The early spring of 2012 with prolonged wet soil conditions in many parts of the country resulted in reports of poor performance of alfalfa due to Aphanomyces root rot (ARR). Varieties with resistance to ARR are available, although fewer varieties have resistance to both race 1 and race 2 of the pat...

  10. [A rare cause of optic neuropathy: Cassava].

    PubMed

    Zeboulon, P; Vignal-Clermont, C; Baudouin, C; Labbé, A

    2016-06-01

    Cassava root is a staple food for almost 500 million people worldwide. Excessive consumption of it is a rare cause of optic neuropathy. Ten patients diagnosed with cassava root related optic neuropathy were included in this retrospective study. Diagnostic criteria were a bilateral optic neuropathy preceded by significant cassava root consumption. Differential diagnoses were excluded through a neuro-ophthalmic examination, blood tests and a brain MRI. All patients had visual field examination and OCT retinal nerve fiber layer (RNFL) analysis as well as an evaluation of their cassava consumption. All patients had a bilateral optic nerve head atrophy or pallor predominantly located into the temporal sector. Visual field defects consisted of a central or cecocentral scotoma for all patients. RNFL showed lower values only in the temporal sector. Mean duration of cassava consumption prior to the appearance of visual symptoms was 22.7±11.2 years with a mean of 2.57±0.53 cassava-based meals per week. Cassava related optic neuropathy is possibly due to its high cyanide content and enabled by a specific amino-acid deficiency. Cassava root chronic consumption is a rare, underappreciated cause of optic neuropathy and its exact mechanism is still uncertain. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Quantitative trait loci controlling cyanogenic glucoside and dry matter content in cassava (Manihot esculenta Crantz) roots.

    PubMed

    Balyejusa Kizito, Elizabeth; Rönnberg-Wästljung, Ann-Christin; Egwang, Thomas; Gullberg, Urban; Fregene, Martin; Westerbergh, Anna

    2007-09-01

    Cassava (Manihot esculenta Crantz) is a starchy root crop grown in the tropics mainly by small-scale farmers even though agro-industrial processing is rapidly increasing. For this processing market improved varieties with high dry matter root content (DMC) is required. Potentially toxic cyanogenic glucosides are synthesized in the leaves and translocated to the roots. Selection for varieties with low cyanogenic glucoside potential (CNP) and high DMC is among the principal objectives in cassava breeding programs. However, these traits are highly influenced by the environmental conditions and the genetic control of these traits is not well understood. An S(1) population derived from a cross between two bred cassava varieties (MCOL 1684 and Rayong 1) that differ in CNP and DMC was used to study the heritability and genetic basis of these traits. A broad-sense heritability of 0.43 and 0.42 was found for CNP and DMC, respectively. The moderate heritabilities for DMC and CNP indicate that the phenotypic variation of these traits is explained by a genetic component. We found two quantitative trait loci (QTL) on two different linkage groups controlling CNP and six QTL on four different linkage groups controlling DMC. One QTL for CNP and one QTL for DMC mapped near each other, suggesting pleiotrophy and/or linkage of QTL. The two QTL for CNP showed additive effects while the six QTL for DMC showed additive effect, dominance or overdominance. This study is a first step towards developing molecular marker tools for efficient breeding of CNP and DMC in cassava.

  12. Comparing methods for inducing root rot of Rhododendron with Phytophthora cinnamomi and P. plurivora

    USDA-ARS?s Scientific Manuscript database

    Root rot, caused by Phytophthora cinnamomi and P. plurivora in containerized Rhododendron, can cause significant losses in the nursery industry. Studies commonly use a 48 h flooding event to stimulate root infection. While flooding rarely occurs in container nurseries, plants may sit in a shallow pu...

  13. Alpha-Glucan, Water Dikinase 1 Affects Starch Metabolism and Storage Root Growth in Cassava (Manihot esculenta Crantz).

    PubMed

    Zhou, Wenzhi; He, Shutao; Naconsie, Maliwan; Ma, Qiuxiang; Zeeman, Samuel C; Gruissem, Wilhelm; Zhang, Peng

    2017-08-29

    Regulation of storage root development by source strength remains largely unknown. The cassava storage root delay (srd) T-DNA mutant postpones storage root development but manifests normal foliage growth as wild-type plants. The SRD gene was identified as an orthologue of α-glucan, water dikinase 1 (GWD1), whose expression is regulated under conditions of light/dark cycles in leaves and is associated with storage root development. The GWD1-RNAi cassava plants showed both retarded plant and storage root growth, as a result of starch excess phenotypes with reduced photosynthetic capacity and decreased levels of soluble saccharides in their leaves. These leaves contained starch granules having greatly increased amylose content and type C semi-crystalline structures with increased short chains that suggested storage starch. In storage roots of GWD1-RNAi lines, maltose content was dramatically decreased and starches with much lower phosphorylation levels showed a drastically reduced β-amylolytic rate. These results suggested that GWD1 regulates transient starch morphogenesis and storage root growth by decreasing photo-assimilation partitioning from the source to the sink and by starch mobilization in root crops.

  14. Root rot symptoms in sugar beet lines caused by Fusarium oxysporum f. sp. betae

    USDA-ARS?s Scientific Manuscript database

    The soil-borne fungus Fusarium oxysporum may cause both Fusarium yellows and Fusarium root rot diseases with severe yield losses in cultivated sugar beet worldwide. These two diseases cause similar foliar symptoms but different root response and have been proposed to be due to two distinct F. oxyspo...

  15. Development of a DNA Microarray-Based Assay for the Detection of Sugar Beet Root Rot Pathogens.

    PubMed

    Liebe, Sebastian; Christ, Daniela S; Ehricht, Ralf; Varrelmann, Mark

    2016-01-01

    Sugar beet root rot diseases that occur during the cropping season or in storage are accompanied by high yield losses and a severe reduction of processing quality. The vast diversity of microorganism species involved in rot development requires molecular tools allowing simultaneous identification of many different targets. Therefore, a new microarray technology (ArrayTube) was applied in this study to improve diagnosis of sugar beet root rot diseases. Based on three marker genes (internal transcribed spacer, translation elongation factor 1 alpha, and 16S ribosomal DNA), 42 well-performing probes enabled the identification of prevalent field pathogens (e.g., Aphanomyces cochlioides), storage pathogens (e.g., Botrytis cinerea), and ubiquitous spoilage fungi (e.g., Penicillium expansum). All probes were proven for specificity with pure cultures from 73 microorganism species as well as for in planta detection of their target species using inoculated sugar beet tissue. Microarray-based identification of root rot pathogens in diseased field beets was successfully confirmed by classical detection methods. The high discriminatory potential was proven by Fusarium species differentiation based on a single nucleotide polymorphism. The results demonstrate that the ArrayTube constitute an innovative tool allowing a rapid and reliable detection of plant pathogens particularly when multiple microorganism species are present.

  16. Laminated root rot damage in a young Douglas-fir stand.

    Treesearch

    E.E. Nelson

    1980-01-01

    Damage occurring from the disease laminated root rot {Phellinus weirii (Murr.) Gilbertson) on two 10-acre plots in a young (40-year-old) stand of Douglas-fir was studied for 25 years. After 25 years, nearly 5 percent of the basal area was killed by the disease. Stand damage caused by vegetative spread of the fungus was significantly related to...

  17. [Research progress in root rot diseases of Chinese herbal medicine and control strategy by antagonistic microorganisms].

    PubMed

    Gao, Fen; Ren, Xiao-xia; Wang, Meng-liang; Qin, Xue-mei

    2015-11-01

    In recent years, root rot diseases of Chinese herbal medicine have been posing grave threat to the development of the traditional Chinese medicine industry. This article presents a review on the occurring situation of the root rot disease, including the occurrence of the disease, the diversity of the pathogens, the regional difference in dominant pathogens,and the complexity of symptoms and a survey of the progress in bio-control of the disease using antagonistic microorganisms. The paper also discusses the existing problems and future prospects in the research.

  18. Influence of sugarbeet tillage Systems on the rhizoctonia-bacterial root rot complex

    USDA-ARS?s Scientific Manuscript database

    The Rhizoctonia-bacterial root rot complex in sugarbeet caused by Rhizoctonia solani and Leuconostoc mesenteroides can cause significant yield losses. To investigate the impact of different tillage systems on this complex, field studies were conducted from 2009 to 2011. Split blocks with conventio...

  19. Seedling mortality and development of root rot in white pine seedlings in two bare-root nurseries

    Treesearch

    J. Juzwik; D. J. Rugg

    1996-01-01

    Seedling mortality and development of root rot in white pine (Pinus strobus) were followed across locations and over time within three operational nursery fields with loamy sand soils at a provincial nursery in southwestern Ontario, Canada, and a state nursery in southern Wisconsin, USA. One Ontario field was fumigated with dazomet; the other was not...

  20. Genetic parameters and prediction of genotypic values for root quality traits in cassava using REML/BLUP.

    PubMed

    Oliveira, E J; Santana, F A; Oliveira, L A; Santos, V S

    2014-08-28

    The aim of this study was to estimate the genetic parameters and predict the genotypic values of root quality traits in cassava (Manihot esculenta Crantz) using restricted maximum likelihood (REML) and best linear unbiased prediction (BLUP). A total of 471 cassava accessions were evaluated over two years of cultivation. The evaluated traits included amylose content (AML), root dry matter (DMC), cyanogenic compounds (CyC), and starch yield (StYi). Estimates of the individual broad-sense heritability of AML were low (hg(2) = 0.07 ± 0.02), medium for StYi and DMC, and high for CyC. The heritability of AML was substantially improved based on mean of accessions (hm(2) = 0.28), indicating that some strategies such as increasing the number of repetitions can be used to increase the selective efficiency. In general, the observed genotypic values were very close to the predicted average of the improved population, most likely due to the high accuracy (>0.90), especially for DMC, CyC, and StYi. Gains via selection of the 30 best genotypes for each trait were 4.8 and 3.2% for an increase and decrease for AML, respectively, an increase of 10.75 and 74.62% for DMC for StYi, respectively, and a decrease of 89.60% for CyC in relation to the overall mean of the genotypic values. Genotypic correlations between the quality traits of the cassava roots collected were generally favorable, although they were low in magnitude. The REML/BLUP method was adequate for estimating genetic parameters and predicting the genotypic values, making it useful for cassava breeding.

  1. Site-specific management of cotton root rot using airborne and satellite imagery

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a serious cotton disease that can now be effectively controlled with Topguard Terra Fungicide. The objectives of this research were to demonstrate how site-specific fungicide application could be implemented based on historical remote sensing imagery and variable rate technology. ...

  2. Evaluating unsupervised and supervised image classification methods for mapping cotton root rot

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot, caused by the soilborne fungus Phymatotrichopsis omnivora, is one of the most destructive plant diseases occurring throughout the southwestern United States. This disease has plagued the cotton industry for over a century, but effective practices for its control are still lacking. R...

  3. Fermentation and crystallization of succinic acid from Actinobacillus succinogenes ATCC55618 using fresh cassava root as the main substrate.

    PubMed

    Thuy, Nguyen Thi Huong; Kongkaew, Artit; Flood, Adrian; Boontawan, Apichat

    2017-06-01

    The fermentation of succinic acid from fresh cassava root using Actinobacillus succinogenes ATCC55618, and the recovery of the product using crystallization were investigated. Fresh cassava root is an ideal succinic acid feedstock due to its low price and high starch content. Saccharification was carried out using commercially available enzymes and diammonium phosphate was used as an inexpensive nitrogen source. Different fermentation modes were compared in terms of product yield and productivity. Results for fed-batch fermentations showed that a succinic acid titer of 151.44g/L, with yield and productivity of 1.51g SA /g glucose and 3.22g/L/h could be obtained. Seeded batch cooling crystallization was investigated after pre-treatment using nanofiltration. A succinic acid crystal purity of 99.35% with a relative crystallinity of 96.77% was obtained from high seeding experiments. These results indicated that fresh cassava roots could be an economically alternative feedstock for a high quality succinic acid production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Putative storage root specific promoters from cassava and yam: cloning and evaluation in transgenic carrots as a model system.

    PubMed

    Arango, Jacobo; Salazar, Bertha; Welsch, Ralf; Sarmiento, Felipe; Beyer, Peter; Al-Babili, Salim

    2010-06-01

    A prerequisite for biotechnological improvements of storage roots is the availability of tissue-specific promoters enabling high expression of transgenes. In this work, we cloned two genomic fragments, pMe1 and pDJ3S, controlling the expression of a gene with unknown function from cassava (Manihot esculenta) and of the storage protein dioscorin 3 small subunit gene from yam (Dioscorea japonica), respectively. Using beta-glucuronidase as a reporter, the activities of pMe1 and pDJ3S were evaluated in independent transgenic carrot lines and compared to the constitutive CaMV35S and the previously described cassava p15 promoters. Activities of pMe1 and pDJ3S in storage roots were assessed using quantitative GUS assays that showed pDJ3S as the most active one. To determine organ specificities, uidA transcript levels in leaves, stems and roots were measured by real-time RT-PCR analyses showing highest storage root specificity for pDJ3S. Root cross sections revealed that pMe1 was highly active in secondary xylem. In contrast, pDJ3S was active in all root tissues except for the central xylem. The expression patterns caused by the cassava p15 promoter in carrot storage roots were consistent with its previously described activities for the original storage organ. Our data demonstrate that the pDJ3S and, to a lesser extent, the pMe1 regulatory sequences represent feasible candidates to drive high and preferential expression of genes in carrot storage roots.

  5. Changes of Cyanide Content and Linamarase Activity in Wounded Cassava Roots 1

    PubMed Central

    Kojima, Mineo; Iwatsuki, Norio; Data, Emma S.; Villegas, Cynthia Dolores V.; Uritani, Ikuzo

    1983-01-01

    When cassava (Manihot esculenta Crantz) root was cut into blocks and incubated under laboratory conditions, the blocks showed more widespread and more even symptoms of physiological deterioration than those under natural conditions. Thus, the tissue block system has potential for biochemical studies of natural deterioration of cassava root. The changes in cyanide content and linamarase (linamarin β-d-glucoside glucohydrolase; EC 3.2.1.21) activity in various tissues during physiological deterioration were investigated. Total cyanide content increased in all parts of block tissue after 3-day incubation. The degree of increase in cyanide was most pronounced in white parenchymal tissue, 2 to 3 millimeters thick, next to the cortex (A-part tissue), where no physiological symptoms appeared. On the other hand, linamarase activity was decreased in all parts of block tissue after a 3-day incubation. A time course analysis of A-part tissue indicated a clear reciprocal relationship between changes in total cyanide and linamarase activity; total cyanide increased, while linamarase activity decreased. Free cyanide constituted a very small portion of the total cyanide and did not change markedly. Images Fig. 2 PMID:16662957

  6. Fate in humans of dietary intake of cyanogenic glycosides from roots of sweet cassava consumed in Cuba.

    PubMed

    Hernández, T; Lundquist, P; Oliveira, L; Pérez Cristiá, R; Rodriguez, E; Rosling, H

    1995-01-01

    We studied if consumption of boiled fresh roots from sweet cassava varieties grown in Cuba resulted in exposure to cyanogenic glycosides and their final breakdown product, cyanide. When adult, nonsmoking subjects consumed 1-4 kg cassava over 2 days, their urinary levels of the main cyanide metabolite, thiocyanate, only increased from a mean +/- SEM of 12 +/- 2 to 22 +/- 2 mumol/l, indicating a negligible cyanide exposure. Their mean urinary linamarin, the main cyanogenic glucoside in cassava, increased from 2 +/- 1 to 68 +/- 16 mumol/l. In a second experiment 5 subjects consumed one meal of 0.5 kg boiled cassava that contained 105 mumol linamarin and 8 mumol hydrogen cyanide (HCN). Quantitative urine collections prior to and after intake showed that 28% of linamarin was excreted during the following 24 hours, whereas a modest increase of urinary thiocyanate (SCN) only corresponded to the small amount of free HCN ingested. These results indicate that the dominant cyanogen in boiled cassava is glycosides that pass through the human body without causing cyanide exposure. It remains to be studied whether humans occasionally possess intestinal or tissue beta-glucosidases that can hydrolyse cyanogenic glycosides from cassava.

  7. Enhanced reactive oxygen species scavenging by overproduction of superoxide dismutase and catalase delays postharvest physiological deterioration of cassava storage roots.

    PubMed

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

    2013-03-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava.

  8. Engineering cyanogen synthesis and turnover in cassava (Manihot esculenta).

    PubMed

    Siritunga, Dimuth; Sayre, Richard

    2004-11-01

    Cassava is the major root crop for a quarter billion subsistence farmers in sub-Saharan Africa. It is valued for its ability to grow in adverse environments and the food security it provides. Cassava contains potentially toxic levels of cyanogenic glycosides (linamarin) which protect the plant from herbivory and theft. The cyanogens, including linamarin and its deglycosylated product, acetone cyanohydrin, can be efficiently removed from the root by various processing procedures. Short-cuts in processing, which may occur during famines, can result in only partial removal of cyanogens. Residual cyanogens in cassava foods may cause neurological disorders or paralysis, particularly in nutritionally compromised individuals. To address this problem and to further understand the function of cyanogenic glycosides in cassava, we have generated transgenic cassava in which cyanogenic glycoside synthesis has been selectively inhibited in leaves and roots by antisense expression of CYP79D1/D2 gene fragments. The CYP79D1/D2 genes encode two highly similar cytochrome P450s that catalyze the first-dedicated step in cyanogenic glycoside synthesis. Transgenic plants in which the expression of these genes was selectively inhibited in leaves had substantially reduced (60- 94% reduction) linamarin leaf levels. Surprisingly, these plants also had a greater than a 99% reduction in root linamarin content. In contrast, transgenic plants in which the CYP79D1/D2 transcripts were reduced to non-detectable levels in roots had normal root linamarin levels. These results demonstrate that linamarin synthesized in leaves is transported to the roots and accounts for nearly all of the root linamarin content. Importantly, transgenic plants having reduced leaf and root linamarin content were unable to grow in the absence of reduced nitrogen (NH3) . Cassava roots have previously been demonstrated to have an active cyanide assimilation pathway leading to the synthesis of amino acids. We propose that

  9. Site-specific management of cotton root rot using historical remote sensing imagery

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot can now be effectively controlled with Topguard Terra Fungicide, but site-specific application of the fungicide can greatly reduce treatment cost as only portions of the field are infested with the disease. The overall goal of this three-year project was to demonstrate how to use his...

  10. Biosynthesis of scopoletin and scopolin in cassava roots during post-harvest physiological deterioration: the E-Z-isomerisation stage.

    PubMed

    Bayoumi, Soad A L; Rowan, Michael G; Blagbrough, Ian S; Beeching, John R

    2008-12-01

    Two to three days after harvesting, cassava (Manihot esculenta Crantz) roots suffer from post-harvest physiological deterioration (PPD) when secondary metabolites are accumulated. Amongst these are hydroxycoumarins (e.g. scopoletin and its glucoside scopolin) which play roles in plant defence and have pharmacological activities. Some steps in the biosynthesis of these molecules are still unknown in cassava and in other plants. We exploit the accumulation of these coumarins during PPD to investigate the E-Z-isomerisation step in their biosynthesis. Feeding cubed cassava roots with E-cinnamic-3,2',3',4',5',6'-d(5) acid gave scopoletin-d(2). However, feeding with E-cinnamic-3,2',3',4',5',6'-d(6) and E-cinnamic-2,3,2',3',4',5',6'-d(7) acids, both gave scopoletin-d(3), the latter not affording the expected scopoletin-d(4). We therefore synthesised and fed with E-cinnamic-2-d(1) when unlabelled scopoletin was biosynthesised. Solely the hydrogen (or deuterium) at C2 of cinnamic acid is exchanged in the biosynthesis of hydroxycoumarins. If the mechanism of E-Z-cinnamic acid isomerisation were photochemical, we would not expect to see the loss of deuterium which we observed. Therefore, a possible mechanism is an enzyme catalysed 1,4-Michael addition, followed by sigma-bond rotation and hydrogen (or deuterium) elimination to yield the Z-isomer. Feeding the roots under light and dark conditions with E-cinnamic-2,3,2',3',4',5',6'-d(7) acid gave scopoletin-d(3) with no significant difference in the yields. We conclude that the E-Z-isomerisation stage in the biosynthesis of scopoletin and scopolin, in cassava roots during PPD, is not photochemical, but could be catalysed by an isomerase which is independent of light.

  11. Influence of tillage systems on Rhizoctonia-bacterial root rot complex in sugar beet

    USDA-ARS?s Scientific Manuscript database

    The Rhizoctonia-bacterial root rot complex on sugarbeet caused by Rhizoctonia solani and Leuconostoc mesenteroides can cause significant yield losses. To investigate the impact of different tillage systems on this complex, field studies were conducted from 2009 to 2011. Split blocks with conventio...

  12. Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber.

    PubMed

    Khabbaz, Salah Eddin; Abbasi, Pervaiz A

    2014-01-01

    Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S-23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%-184% and percentage of healthy seedlings by 100%-290%, and decreased damping-off and root rot severity by 27%-50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 10(8) CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing

  13. Evaluating spectral measures derived from airborne multispectral imagery for detecting cotton root rot

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot, caused by the soilborne fungus Phymatotrichopsis omnivore, is one of the most destructive plant diseases occurring throughout the southwestern United States. This disease has plagued the cotton industry for more than 100 years, but effective practices for its control are still lacki...

  14. Provitamin A biofortification of cassava enhances shelf life but reduces dry matter content of storage roots due to altered carbon partitioning into starch.

    PubMed

    Beyene, Getu; Solomon, Felix R; Chauhan, Raj D; Gaitán-Solis, Eliana; Narayanan, Narayanan; Gehan, Jackson; Siritunga, Dimuth; Stevens, Robyn L; Jifon, John; Van Eck, Joyce; Linsler, Edward; Gehan, Malia; Ilyas, Muhammad; Fregene, Martin; Sayre, Richard T; Anderson, Paul; Taylor, Nigel J; Cahoon, Edgar B

    2017-11-28

    Storage roots of cassava (Manihot esculenta Crantz), a major subsistence crop of sub-Saharan Africa, are calorie rich but deficient in essential micronutrients, including provitamin A β-carotene. In this study, β-carotene concentrations in cassava storage roots were enhanced by co-expression of transgenes for deoxy-d-xylulose-5-phosphate synthase (DXS) and bacterial phytoene synthase (crtB), mediated by the patatin-type 1 promoter. Storage roots harvested from field-grown plants accumulated carotenoids to ≤50 μg/g DW, 15- to 20-fold increases relative to roots from nontransgenic plants. Approximately 85%-90% of these carotenoids accumulated as all-trans-β-carotene, the most nutritionally efficacious carotenoid. β-Carotene-accumulating storage roots displayed delayed onset of postharvest physiological deterioration, a major constraint limiting utilization of cassava products. Large metabolite changes were detected in β-carotene-enhanced storage roots. Most significantly, an inverse correlation was observed between β-carotene and dry matter content, with reductions of 50%-60% of dry matter content in the highest carotenoid-accumulating storage roots of different cultivars. Further analysis confirmed a concomitant reduction in starch content and increased levels of total fatty acids, triacylglycerols, soluble sugars and abscisic acid. Potato engineered to co-express DXS and crtB displayed a similar correlation between β-carotene accumulation, reduced dry matter and starch content and elevated oil and soluble sugars in tubers. Transcriptome analyses revealed a reduced expression of genes involved in starch biosynthesis including ADP-glucose pyrophosphorylase genes in transgenic, carotene-accumulating cassava roots relative to nontransgenic roots. These findings highlight unintended metabolic consequences of provitamin A biofortification of starch-rich organs and point to strategies for redirecting metabolic flux to restore starch production. © 2017 The

  15. The BioCassava Plus program: Biofortification of cassava for sub-Saharan Africa

    USDA-ARS?s Scientific Manuscript database

    More than 250 million Africans rely on the starchy root crop cassava (Manihot esculenta) as their staple source of calories. A typical cassava-based diet, however, provides less than 30% of the minimum daily requirement for protein and only 10-20% of that for iron, zinc, and vitamin A. The BioCassav...

  16. Effect of cassava peel and cassava bagasse natural fillers on mechanical properties of thermoplastic cassava starch: Comparative study

    NASA Astrophysics Data System (ADS)

    Edhirej, Ahmed; Sapuan, S. M.; Jawaid, Mohammad; Zahari, Nur Ismarrubie; Sanyang, M. L.

    2017-12-01

    Increased awareness of environmental and sustainability issues has generated increased interest in the use of natural fiber reinforced composites. This work focused on the use of cassava roots peel and bagasse as natural fillers of thermoplastic cassava starch (TPS) materials based on cassava starch. The effect of cassava bagasse (CB) and cassava peel (CP) content on the tensile properties of cassava starch (CS) biocomposites films was studied. The biocomposites films were prepared by casting technique using cassava starch (CS) as matrix and fructose as plasticizer. The CB and CP were added to improve the properties of the films. The addition of both fibers increased the tensile strength and modulus while decreased the elongation at break of the biocomposites films. Films containing CB showed higher tensile strength and modulus as compared to the films containing the same amount of CP. The addition of 6 % bagasse increased the modulus and maximum tensile stress to 581.68 and 10.78 MPa, respectively. Thus, CB is considered to be the most efficient reinforcing agent due to its high compatibility with the cassava starch. The use of CB and CP as reinforcement agents for CS thermoplastic cassava added value to these waste by-products and increase the suitability of CS composite films as environmentally friendly food packaging material.

  17. Leaf proteomic analysis in cassava (Manihot esculenta, Crantz) during plant development, from planting of stem cutting to storage root formation.

    PubMed

    Mitprasat, Mashamon; Roytrakul, Sittiruk; Jiemsup, Surasak; Boonseng, Opas; Yokthongwattana, Kittisak

    2011-06-01

    Tuberization in cassava (Manihot esculenta Crantz) occurs simultaneously with plant development, suggesting competition of photoassimilate partitioning between the shoot and the root organs. In potato, which is the most widely studied tuber crop, there is ample evidence suggesting that metabolism and regulatory processes in leaf may have an impact on tuber formation. To search for leaf proteins putatively involved in regulating tuber generation and/or development in cassava, comparative proteomic approaches have been applied to monitor differentially expressed leaf proteins during root transition from fibrous to tuberous. Stringent cross comparison and statistical analysis between two groups with different plant ages using Student's t test with 95% significance level revealed a number of protein spots whose abundance were significantly altered (P < 0.05) during week 4 to week 8 of growth. Of these, 39 spots were successfully identified by ion trap LC-MS/MS. The proteins span various functional categories from antioxidant and defense, carbohydrate metabolism, cyanogenesis, energy metabolism, miscellaneous and unknown proteins. Results suggested possible metabolic switches in the leaf that may trigger/regulate storage root initiation and growth. This study provides a basis for further functional characterization of differentially expressed leaf proteins, which can help understand how biochemical processes in cassava leaves may be involved in storage root development.

  18. Metabolomics combined with chemometric tools (PCA, HCA, PLS-DA and SVM) for screening cassava (Manihot esculenta Crantz) roots during postharvest physiological deterioration.

    PubMed

    Uarrota, Virgílio Gavicho; Moresco, Rodolfo; Coelho, Bianca; Nunes, Eduardo da Costa; Peruch, Luiz Augusto Martins; Neubert, Enilto de Oliveira; Rocha, Miguel; Maraschin, Marcelo

    2014-10-15

    Cassava roots are an important source of dietary and industrial carbohydrates and suffer markedly from postharvest physiological deterioration (PPD). This paper deals with metabolomics combined with chemometric tools for screening the chemical and enzymatic composition in several genotypes of cassava roots during PPD. Metabolome analyses showed increases in carotenoids, flavonoids, anthocyanins, phenolics, reactive scavenging species, and enzymes (superoxide dismutase family, hydrogen peroxide, and catalase) until 3-5days postharvest. PPD correlated negatively with phenolics and carotenoids and positively with anthocyanins and flavonoids. Chemometric tools such as principal component analysis, partial least squares discriminant analysis, and support vector machines discriminated well cassava samples and enabled a good prediction of samples. Hierarchical clustering analyses grouped samples according to their levels of PPD and chemical compositions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    PubMed

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  20. Creating prescription maps from historical imagery for site-specific management of cotton root rot

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot, caused by the soilborne fungus Phymatotrichopsis omnivore, is a severe plant disease that has affected cotton production for over a century. Recent research found that a commercial fungicide, Topguard (flutriafol), was able to control this disease. As a result, Topguard Terra Fungic...

  1. Using airborne imagery to monitor cotton root rot infection before and after fungicide treatment

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a severe soilborne disease that has affected cotton production for over a century. Recent research has shown that a commercial fungicide, flutriafol, has potential for the control of this disease. To effectively and economically control this disease, it is necessary to identify in...

  2. First report of Phytophthora root rot, caused by Phytophthora cryptogea, on spinach in California

    USDA-ARS?s Scientific Manuscript database

    In 2006 and 2007, commercially grown spinach (Spinacia oleracea) in California’s coastal Salinas Valley (Monterey County) was affected by an unreported root rot disease. Disease was limited to patches along the edges of fields. Affected plants were stunted with chlorotic older leaves. As disease pro...

  3. Sugar-mediated semidian oscillation of gene expression in the cassava storage root regulates starch synthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jansson, Christer; Baguma, Yona; Sun, Chuanxin

    Starch branching enzyme (SBE) activity in the cassava storage root exhibited a diurnal fluctuation, dictated by a transcriptional oscillation of the corresponding SBE genes. The peak of SBE activity coincided with the onset of sucrose accumulation in the storage, and we conclude that the oscillatory mechanism keeps the starch synthetic apparatus in the storage root sink in tune with the flux of sucrose from the photosynthetic source. When storage roots were uncoupled from the source, SBE expression could be effectively induced by exogenous sucrose. Turanose, a sucrose isomer that cannot be metabolized by plants, mimicked the effect of sucrose, demonstratingmore » that downstream metabolism of sucrose was not necessary for signal transmission. Also glucose and glucose-1-P induced SBE expression. Interestingly, induction by sucrose, turanose and glucose but not glucose-1-P sustained an overt semidian (12-h) oscillation in SBE expression and was sensitive to the hexokinase (HXK) inhibitor glucosamine. These results suggest a pivotal regulatory role for HXK during starch synthesis. Abscisic acid (ABA) was another potent inducer of SBE expression. Induction by ABA was similar to that of glucose-1-P in that it bypassed the semidian oscillator. Both the sugar and ABA signaling cascades were disrupted by okadaic acid, a protein phosphatase inhibitor. Based on these findings, we propose a model for sugar signaling in regulation of starch synthesis in the cassava storage root.« less

  4. Starch determination, amylose content and susceptibility to in vitro amylolysis in flours from the roots of 25 cassava varieties.

    PubMed

    Mejía-Agüero, Luisa Elena; Galeno, Florangel; Hernández-Hernández, Oswaldo; Matehus, Juan; Tovar, Juscelino

    2012-02-01

    Cassava cultivars are classified following different criteria, such as cyanogenic glucoside content or starch content. Here, flours from the roots of 25 cassava varieties cultivated simultaneously in a single plantation, were characterized in terms of starch content (SC), amylose content (AC), α-amylolysis index (AI) and gel formation ability. Resistant starch content (RS) was measured in 10 of the samples. Cassava flours exhibited high SC, low AC and low AI values, with differences among varieties. Cluster analysis based on these parameters divided the cultivars in four groups differing mainly in SC and AC. AI and AC were inversely correlated (r = -0.59, P < 0.05) in 18 of the cultivars, suggesting AC as an important factor governing the susceptibility to enzymatic hydrolysis of starch in raw cassava. Differences in susceptibility to amylolysis, assessed by RS, were also recorded in the sample subset analyzed. Most flours yielded pastes or gels upon heating and cooling. Gels differed in their subjective grade of firmness, but none exhibited syneresis, confirming the low retrogradation proclivity of cassava starch. Some differences were found among cassava samples, which may be ascribed to inter-cultivar variation. This information may have application in further agronomic studies or for developing industrial uses for this crop. Copyright © 2011 Society of Chemical Industry.

  5. AFLP-based transcript profiling for cassava genome-wide expression analysis in the onset of storage root formation.

    PubMed

    Sojikul, Punchapat; Kongsawadworakul, Panida; Viboonjun, Unchera; Thaiprasit, Jittrawan; Intawong, Burapat; Narangajavana, Jarunya; Svasti, Mom Rajawong Jisnuson

    2010-10-01

    Cassava (Manihot esculenta Crantz) is a root crop that accumulates large quantities of starch, and it is an important source of carbohydrate. Study on gene expressions during storage root development provides important information on storage root formation and starch accumulation as well as unlock new traits for improving of starch yield. cDNA-Amplified Fragment Length Polymorphism (AFLP) was used to compare gene expression profiles in fibrous and storage roots of cassava cultivar Kasetsart 50. Total of 155 differentially expressed transcript-derived fragments with undetectable or low expression in leaves were characterized and classified into 11 groups regarding to their functions. The four major groups were no similarity (20%), hypothetical or unknown proteins (17%), cellular metabolism and biosynthesis (17%) and cellular communication and signaling (14%). Interestingly, sulfite reductase (MeKD82), calcium-dependent protein kinase (CDPK) (MeKD83), ent-kaurene synthase (KS) (MeKD106) and hexose transporter (HT) (MeKD154) showed root-specific expression patterns. This finding is consistent with previously reported genes involved in the initiation of potato tuber. Semi-quantitative reverse transcription polymerase chain reaction of early-developed root samples confirmed that those four genes exhibited significant expression with similar pattern in the storage root initiation and early developmental stages. We proposed that KS and HT may involve in transient induction of CDPK expression, which may play an important role in the signaling pathway of storage root initiation. Sulfite reductase, on the other hand, may involve in storage root development by facilitating sulfur-containing protein biosynthesis or detoxifying the cyanogenic glucoside content through aspartate biosynthesis. Copyright © Physiologia Plantarum 2010.

  6. Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

    PubMed

    Macedo, Renan; Sales, Lilian Patrícia; Yoshida, Fernanda; Silva-Abud, Lidianne Lemes; Lobo, Murillo

    2017-01-01

    Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans.

  7. Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence

    PubMed Central

    Macedo, Renan; Sales, Lilian Patrícia; Yoshida, Fernanda; Silva-Abud, Lidianne Lemes

    2017-01-01

    Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen’s optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen’s density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans. PMID:29107985

  8. Creating prescription maps from satellite imagery for site-specific management of cotton root rot

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a century-old cotton disease that can now be controlled with Topguard Terra Fungicide. However, as this disease tends to occur in the same general areas within fields year after year, site-specific treatment can be more effective and economical. The objective of this study was to ...

  9. Seventeen years of research on genetics of resistance to Aphanomyces root rot of pea

    USDA-ARS?s Scientific Manuscript database

    Aphanomyces root rot, caused by the oomycete Aphanomyces euteiches, is a major soil borne disease of pea in many countries. Genetic resistance is considered to be a main way to control the disease. Since 2000, INRA has engaged a long-term research program to study genetic resistance to A. euteiches ...

  10. Prediction of carotenoids, cyanide and dry matter contents in fresh cassava root using NIRS and Hunter color techniques.

    PubMed

    Sánchez, T; Ceballos, H; Dufour, D; Ortiz, D; Morante, N; Calle, F; Zum Felde, T; Domínguez, M; Davrieux, F

    2014-05-15

    Efforts are currently underway to improve carotenoids content in cassava roots through conventional breeding as a strategy to reduce vitamin A deficiency. However, only few samples can be quantified each day for total carotenoids (TCC) and β-carotene (TBC) contents, limiting the gains from breeding. A database with >3000 samples was used to evaluate the potential of NIRS and chromameter devices to predict root quality traits. Maximum TTC and TBC were up to 25.5 and 16.6 μg/g (fresh weight basis), respectively. NIRS predictions were highly satisfactory for dry matter content (DMC, R(2): 0.96), TCC (R(2): 0.92) and TBC (R(2): 0.93). NIRS could also distinguish roots with high or low cyanogenic potential (R(2): 0.86). Hunter color parameters could also be used for predictions, but with lower accuracy than NIRS. NIRS or chromameter improve selection protocols, allowing faster gains from breeding. Results also demonstrate that TBC and DMC can be improved simultaneously (required for the adoption of biofortified cassava). Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Overexpression of Arabidopsis VIT1 increases accumulation of iron in cassava roots and stems.

    PubMed

    Narayanan, Narayanan; Beyene, Getu; Chauhan, Raj Deepika; Gaitán-Solis, Eliana; Grusak, Michael A; Taylor, Nigel; Anderson, Paul

    2015-11-01

    Iron is extremely abundant in the soil, but its uptake in plants is limited due to low solubility in neutral or alkaline soils. Plants can rely on rhizosphere acidification to increase iron solubility. AtVIT1 was previously found to be involved in mediating vacuolar sequestration of iron, which indicates a potential application for iron biofortification in crop plants. Here, we have overexpressed AtVIT1 in the starchy root crop cassava using a patatin promoter. Under greenhouse conditions, iron levels in mature cassava storage roots showed 3-4 times higher values when compared with wild-type plants. Significantly, the expression of AtVIT1 showed a positive correlation with the increase in iron concentration of storage roots. Conversely, young leaves of AtVIT1 transgenic plants exhibit characteristics of iron deficiency such as interveinal chlorosis of leaves (yellowing) and lower iron concentration when compared with the wild type plants. Interestingly, the AtVIT1 transgenic plants showed 4 and 16 times higher values of iron concentration in the young stem and stem base tissues, respectively. AtVIT1 transgenic plants also showed 2-4 times higher values of iron content when compared with wild-type plants, with altered partitioning of iron between source and sink tissues. These results demonstrate vacuolar iron sequestration as a viable transgenic strategy to biofortify crops and to help eliminate micronutrient malnutrition in at-risk human populations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Combining fuzzy set theory and nonlinear stretching enhancement for unsupervised classification of cotton root rot

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a destructive disease affecting cotton production. Accurate identification of infected areas within fields is useful for cost-effective control of the disease. The uncertainties caused by various infection stages and newly infected plants make it difficult to achieve accurate clas...

  13. Irrigation affects severity of root rot caused by Phythophthora plurivora and P. cinnamomi on rhododendron

    USDA-ARS?s Scientific Manuscript database

    Plant pathogens in the genus Phytophthora cause root rot that decrease product quality and result in plant death and economic losses to the nursery industry. Recently, we found Phytophthora plurivora prevalent on rhododendron in nurseries in the Pacific Northwest, USA, but there is little informatio...

  14. Enhanced Reactive Oxygen Species Scavenging by Overproduction of Superoxide Dismutase and Catalase Delays Postharvest Physiological Deterioration of Cassava Storage Roots1[C][W][OA

    PubMed Central

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R.; Zhang, Peng

    2013-01-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava. PMID:23344905

  15. Cyanide production by Pseudomonas fluorescens helps suppress black root rot of tobacco under gnotobiotic conditions

    PubMed Central

    Voisard, Christophe; Keel, Christoph; Haas, Dieter; Dèfago, Geneviève

    1989-01-01

    Pseudomonas fluorescens CHA0 suppresses black root rot of tobacco, a disease caused by the fungus Thielaviopsis basicola. Strain CHA0 excretes several metabolites with antifungal properties. The importance of one such metabolite, hydrogen cyanide, was tested in a gnotobiotic system containing an artificial, iron-rich soil. A cyanidenegative (hcn) mutant, CHA5, constructed by a gene replacement technique, protected the tobacco plant less effectively than did the wild-type CHA0. Complementation of strain CHA5 by the cloned wild-type hcn+ genes restored the strain's ability to suppress disease. An artificial transposon carrying the hcn+ genes of strain CHA0 (Tnhcn) was constructed and inserted into the genome of another P.fluorescens strain, P3, which naturally does not produce cyanide and gives poor plant protection. The P3::Tnhcn derivative synthesized cyanide and exhibited an improved ability to suppress disease. All bacterial strains colonized the roots similarly and did not influence significantly the survival of T.basicola in soil. We conclude that bacterial cyanide is an important but not the only factor involved in suppression of black root rot. Images PMID:16453871

  16. Cassava For Space Diet

    NASA Astrophysics Data System (ADS)

    Katayama, Naomi; Yamashita, Masamichi; Njemanze, Philip; Nweke, Felix; Mitsuhashi, Jun; Hachiya, Natumi; Miyashita, Sachiko; Hotta, Atuko

    Space agriculture is an advanced life support enginnering concept based on biological and ecological system ot drive the materials recycle loop and create pleasant life environment on distant planetary bodies. Choice of space diet is one of primary decision required ot be made at designing space agriculture. We propose cassava, Manihot esculenta and, for one major composition of space food materials, and evaluate its value and feasibility of farming and processing it for space diet. Criteria to select space crop species could be stated as follows. 1) Fill th enutritional requirements. There is no perfect food material to meet this requirements without making a combination with others. A set of food materials which are adopted inthe space recipe shall fit to the nutritional requirement. 2) Space food is not just for maintaining physiological activities of human, but an element of human culture. We shall consider joy of dining in space life. In this context, space foos or recipe should be accepted by future astronauts. Food culture is diverse in the world, and has close relatioship to each cultural background. Cassava root tuber is a material to supply mainly energy in the form of carbohydrate, same as cereals and other tuber crops. Cassava leaf is rich in protein high as 5.1 percents about ten times higher content than its tuber. In the food culture in Africa, cassava is a major component. Cassava root tuber in most of its strain contains cyanide, it should be removed during preparation for cooking. However certain strain are less in this cyanogenic compound, and genetically modified cassava can also aboid this problem safely.

  17. Kinetics of mass transfer during deep fat frying of yellow fleshed cassava root slices

    NASA Astrophysics Data System (ADS)

    Oyedeji, A. B.; Sobukola, O. P.; Henshaw, F. O.; Adegunwa, M. O.; Sanni, L. O.; Tomlins, K. I.

    2016-05-01

    Kinetics of mass transfer [moisture content, oil uptake, total carotenoid (TC) and shrinkage] during frying of yellow fleshed cassava roots (TMS 01/1371) was investigated. Slices were divided into (i) fresh and (ii) pre-dried to 75 % moisture content before atmospheric frying and (iii) vacuum fried. Percentage TC and activation energies of vacuum, fresh and pre-dried fried samples were 76, 63 and 61 %; and 82, 469.7, 213.7 kJ/mol, respectively.

  18. Efficacy of management tools for control of Pythium root rot of Douglas-fir seedlings, 2013

    USDA-ARS?s Scientific Manuscript database

    This study was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rots of ornamental plants caused by Pythium species. Pythium species used in this study were P. vipa (isolate 09), P. dissotocum (isolate 41-08...

  19. Occurrence of the root-rot pathogen, Fusarium commune, in midwestern and western United States

    Treesearch

    J. E. Stewart; R. K. Dumroese; N. B. Klopfenstein; M. -S. Kim

    2012-01-01

    Fusarium commune can cause damping-off and root rot of conifer seedlings in forest nurseries. The pathogen is only reported in Oregon, Idaho, and Washington within United States. Fusarium isolates were collected from midwestern and western United States to determine occurrence of this pathogen. DNA sequences of mitochondrial small subunit gene were used to identify F....

  20. Integration of soil application and seed treatment formulations of Trichoderma species for management of wet root rot of mungbean caused by Rhizoctonia solani.

    PubMed

    Dubey, Sunil C; Bhavani, Ranganaicker; Singh, Birendra

    2011-09-01

    The efficacy of seed dressing and soil application formulations from the isolates of Trichoderma viride (IARI P1; MTCC 5369), T. virens (IARI P3; MTCC 5370) and T. harzianum (IARI P4; MTCC 5371) were evaluated individually and in combination in pot and field experiments during the rainy seasons of 2005, 2006 and 2007 for the management of wet root rot (Rhizoctonia solani) and improvement in the yield of mungbean. A seed dressing formulation, Pusa 5SD, and soil application formulations, Pusa Biogranule 6 (PBG 6) and Pusa Biopellet 16G (PBP 16G), based on Trichoderma virens, were found to be superior to other formulations in reducing disease incidence and increasing seed germination and shoot and root lengths in mungbean. In field experiments, a combination of soil application with PBP 16G (T. virens) and seed treatment with Pusa 5SD (T. virens) + carboxin was superior to any of these formulations individually in increasing seed germination, shoot and root lengths and grain yield and reducing wet root rot incidence in mungbean. Seed treatment was more effective than soil application for all the evaluated parameters. The combined application of Pusa 5SD and carboxin was also superior to individual treatment. The efficacy of the evaluated formulations against wet root rot of mungbean proved that the integration of soil application of PBP 16G and seed treatment with Pusa 5SD + carboxin is highly effective for the management of wet root rot, increasing plant growth and grain yield of mungbean. Copyright © 2011 Society of Chemical Industry.

  1. Bark analysis as a guide to cassava nutrition in Sierra Leone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Godfrey-Sam-Aggrey, W.; Garber, M.J.

    1979-01-01

    Cassava main stem barks from two experiments in which similar fertilizers were applied directly in a 2/sup 5/ confounded factorial design were analyzed and the bark nutrients used as a guide to cassava nutrition. The application of multiple regression analysis to the respective root yields and bark nutrient concentrations enable nutrient levels and optimum adjusted root yields to be derived. Differences in bark nutrient concentrations reflected soil fertility levels. Bark analysis and the application of multiple regression analysis to root yields and bark nutrients appear to be useful tools for predicting fertilizer recommendations for cassava production.

  2. Temperature, Moisture, and Fungicide Effects in Managing Rhizoctonia Root and Crown Rot of Sugar Beet

    USDA-ARS?s Scientific Manuscript database

    Rhizoctonia solani AG-2-2 is the causal agent of Rhizoctonia root and crown rot in sugar beet. To assess the capacity at which other anastomosis groups (AGs) are able to infect sugar beet, 15 AGs and subgroups were tested for pathogenicity on resistant (FC708 CMS) and susceptible (Monohikari) seedl...

  3. Cassava (Manihot esculenta Krantz) genome harbors KNOX genes differentially expressed during storage root development.

    PubMed

    Guo, D; Li, H L; Tang, X; Peng, S Q

    2014-12-18

    In plants, homeodomain proteins play a critical role in regulating various aspects of plant growth and development. KNOX proteins are members of the homeodomain protein family. The KNOX transcription factors have been reported from Arabidopsis, rice, and other higher plants. The recent publication of the draft genome sequence of cassava (Manihot esculenta Krantz) has allowed a genome-wide search for M. esculenta KNOX (MeKNOX) transcription factors and the comparison of these positively identified proteins with their homologs in model plants. In the present study, we identified 12 MeKNOX genes in the cassava genome and grouped them into two distinct subfamilies based on their domain composition and phylogenetic analysis. Furthermore, semi-quantitative reverse transcription polymerase chain reaction analysis was performed to elucidate the expression profiles of these genes in different tissues and during various stages of root development. The analysis of MeKNOX expression profiles of indicated that 12 MeKNOX genes display differential expressions either in their transcript abundance or expression patterns.

  4. In vitro cultured primary roots derived from stem segments of cassava (Manihot esculenta) can behave like storage organs.

    PubMed

    Medina, Ricardo D; Faloci, Mirta M; Gonzalez, Ana M; Mroginski, Luis A

    2007-03-01

    Cassava (Manihot esculenta) has three adventitious root types: primary and secondary fibrous roots, and storage roots. Different adventitious root types can also regenerate from in vitro cultured segments. The aim of this study was to investigate aspects of in vitro production of storage roots. Morphological and anatomical analyses were performed to identify and differentiate each root type. Twenty-nine clones were assayed to determine the effect of genotype on the capacity to form storage roots in vitro. The effects of cytokinins and auxins on the formation of storage roots in vitro were also examined. Primary roots formed in vitro and in vivo had similar tissue kinds; however, storage roots formed in vitro exhibited physiological specialization for storing starch. The only consistent diagnostic feature between secondary fibrous and storage roots was their functional differentiation. Anatomical analysis of the storage roots formed in vitro showed that radial expansion as a consequence of massive proliferation and enlargement of parenchymatous cells occurred in the middle cortex, but not from cambial activity as in roots formed in vivo. Cortical expansion could be related to dilatation growth favoured by hormone treatments. Starch deposition of storage roots formed in vitro was confined to cortical tissue and occurred earlier than in storage roots formed in vivo. Auxin and cytokinin supplementation were absolutely required for in vitro storage root regeneration; these roots were not able to develop secondary growth, but formed a tissue competent for starch storing. MS medium with 5 % sucrose plus 0.54 microM 1-naphthaleneacetic acid and 0.44 microM 6-benzylaminopurine was one of the most effective in stimulating the storage root formation. Genotypes differed significantly in their capacity to produce storage roots in vitro. Storage root formation was considerably affected by the segment's primary position and strongly influenced by hormone treatments. The storage

  5. In vitro Cultured Primary Roots Derived from Stem Segments of Cassava (Manihot esculenta) Can Behave Like Storage Organs

    PubMed Central

    Medina, Ricardo D.; Faloci, Mirta M.; Gonzalez, Ana M.; Mroginski, Luis A.

    2007-01-01

    Background and Aims Cassava (Manihot esculenta) has three adventitious root types: primary and secondary fibrous roots, and storage roots. Different adventitious root types can also regenerate from in vitro cultured segments. The aim of this study was to investigate aspects of in vitro production of storage roots. Methods Morphological and anatomical analyses were performed to identify and differentiate each root type. Twenty-nine clones were assayed to determine the effect of genotype on the capacity to form storage roots in vitro. The effects of cytokinins and auxins on the formation of storage roots in vitro were also examined. Key Results Primary roots formed in vitro and in vivo had similar tissue kinds; however, storage roots formed in vitro exhibited physiological specialization for storing starch. The only consistent diagnostic feature between secondary fibrous and storage roots was their functional differentiation. Anatomical analysis of the storage roots formed in vitro showed that radial expansion as a consequence of massive proliferation and enlargement of parenchymatous cells occurred in the middle cortex, but not from cambial activity as in roots formed in vivo. Cortical expansion could be related to dilatation growth favoured by hormone treatments. Starch deposition of storage roots formed in vitro was confined to cortical tissue and occurred earlier than in storage roots formed in vivo. Auxin and cytokinin supplementation were absolutely required for in vitro storage root regeneration; these roots were not able to develop secondary growth, but formed a tissue competent for starch storing. MS medium with 5 % sucrose plus 0·54 μm 1-naphthaleneacetic acid and 0·44 μm 6-benzylaminopurine was one of the most effective in stimulating the storage root formation. Genotypes differed significantly in their capacity to produce storage roots in vitro. Storage root formation was considerably affected by the segment's primary position and strongly

  6. Breeding cassava for higher yield

    USDA-ARS?s Scientific Manuscript database

    Cassava is a root crop grown for food and for starch production. Breeding progress is slowed by asexual production and high levels of heterozygosity. Germplasm resources are rich and accessible to breeders through genebanks worldwide. Breeding objectives include high root yield, yield stability, dis...

  7. Change detection of cotton root rot infection over a 10-year interval using airborne multispectral imagery

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a very serious and destructive disease of cotton grown in the southwestern and south central United States. Accurate information regarding the spatial and temporal infections of the disease within fields is important for effective management and control of the disease. The objecti...

  8. Low dietary cyanogen exposure from frequent consumption of potentially toxic cassava in Malawi.

    PubMed

    Chiwona-Karltun, L; Tylleskär, T; Mkumbira, J; Gebre-Medhin, M; Rosling, H

    2000-01-01

    In a cassava-growing area in Malawi, where roots are processed by soaking and water is available throughout the year, we interviewed 176 women farmers regarding their preferences for cassava cultivars and frequency of cassava consumption. Dietary cyanogen exposure was estimated from urinary levels of linamarin, the cyanogenic glycoside in cassava, and urinary thiocyanate, the main cyanide metabolite. Protection against unplanned harvest by family members, theft and animal spoilage were stated to be very important reasons for growing bitter cassava cultivars by 91%, 90% and 74% of the women, respectively. The mean (+/- SD) number of cultivars grown by each woman was 4.6 (+/- 2.4). The correlation between mean taste and mean danger scores for the 25 most grown cultivars was strong (r > 0.98). The scoring indicated that cultivars belonged to two distinct groups, eight to a group referred to as 'cool' and 17 to a group termed 'bitter'. The dumpling-like porridge (kondowole) made from cassava flour from bitter roots was eaten twice daily by 51% and at least weekly by 81%. The mean (+/- SEM) urinary linamarin was 14 (+/- 1) mumol/L and thiocyanate was 50 (+/- 4) mumol/L, less than a tenth of levels reported from populations eating insufficiently processed bitter cassava roots, and in the same range as in a non-smoking Swedish reference population. We conclude that cyanogenesis is a preferred characteristic of cassava by the studied farmers because it enhances food security. The availability of water and their knowledge about toxicity and processing enables these women farmers to provide a safe staple food from bitter cassava roots.

  9. Root Interactions in a Maize/Soybean Intercropping System Control Soybean Soil-Borne Disease, Red Crown Rot

    PubMed Central

    Gao, Xiang; Wu, Man; Xu, Ruineng; Wang, Xiurong; Pan, Ruqian; Kim, Hye-Ji; Liao, Hong

    2014-01-01

    Background Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. Principal Findings In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum). The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. Conclusions To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices. PMID:24810161

  10. Isolation screening and characterisation of local beneficial rhizobacteria based upon their ability to suppress the growth of Fusarium oxysporum f. sp. radicis-lycopersici and tomato foot and root rot

    USDA-ARS?s Scientific Manuscript database

    Tomato crown and root rot or tomato foot and root rot (TFRR) is caused by the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici (Forl). The disease occurs in both greenhouse and outdoor tomato cultivations and cannot be treated efficiently with the existing fungicides. We conducte...

  11. Site-specific management of cotton root rot using airborne and satellite imagery and variable rate technology

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a serious cotton disease that can now be effectively controlled with Topguard Terra Fungicide. However, its recurrence in the same areas year after year makes fungicide application only to infested areas more effective and economical than uniform application. Base on 17 years of r...

  12. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    PubMed

    Fang, Xiangling; Finnegan, Patrick M; Barbetti, Martin J

    2013-01-01

    Strawberry (Fragaria×ananassa) is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR). Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG). Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B) or in Australia (e.g., AG-G). The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  13. DNA-based characterization of wood-, butt- and root-rot fungi from the western Pacific Islands

    Treesearch

    Sara M. Ashiglar; Phil G. Cannon; Robert L. Schlub; Mee-Sook Kim; Yuko Ota; Norio Sahashi; Ned B. Klopfenstein

    2015-01-01

    Although the islands of the western Pacific comprise a hotspot of species, including fungi, a large number of these species have not been catalogued or documented in the scientific literature on an island to island basis. Butt- and root-rot fungi were collected from infected wood and fruiting bodies of diverse tropical trees from forest, agricultural, and...

  14. Production of ethanol from raw cassava starch by a nonconventional fermentation method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ueda, S.; Zenin, C.T.; Monteiro, D.A.

    Raw cassava root starch was transformed into ethanol in a one-step process of fermentation, in which are combined the conventional processes of liquefaction, saccharification, and fermentation to alcohol. Aspergillus awamori NRRL 3112 and Aspergillus niger were cultivated on wheat bran and used as Koji enzymes. Commercial A. niger amyloglucosidase was also used in this experiment. A raw cassava root homogenate-enzymes-yeast mixture fermented optimally at pH 3.5 and 30/degree/C, for five days and produced ethanol. Alcohol yields from raw cassava roots were between 82.3 and 99.6%. Fungal Koji enzymes effectively decreased the viscosity of cassava root fermentation mashes during incubation. Commercialmore » A. niger amyloglucosidase decreased the viscosity slightly. Reduction of viscosity of fermentation mashes was 40, 84, and 93% by commercial amyloglucosidase, A. awamori, and A. niger enzymes, respectively. The reduction of viscosity of fermentation mashes is probably due to the hydrolysis of pentosans by Koji enzymes. 12 refs.« less

  15. Identification and expression analyses of new potential regulators of xylem development and cambium activity in cassava (Manihot esculenta).

    PubMed

    Siebers, Tyche; Catarino, Bruno; Agusti, Javier

    2017-03-01

    We have identified new potential regulators of xylem cell-type determination and cellular proliferation in cassava and studied their expression in roots. Results are highly relevant for cassava biotechnology. Cassava's root system is composed of two types of root that coexist in every individual: the fibrous and the storage roots. Whether a root becomes fibrous or storage depends on the xylem cell types that it develops: fibrous roots develop xylem fibres and vessels while storage roots develop parenchyma xylem, the starch-storing tissue. A crucial question in cassava root development is how the specific xylem cell types differentiate and proliferate in the fibrous and storage roots. Using phylogenetic, protein sequence and synteny analyses we identified (1) MeVND6, MeVND7.1, MeVND7.2, MeNST3.1 and MeNST3.2 as the potential cassava orthologues of the Arabidopsis regulators of xylem cell type determination AtVND6, AtVND7 and AtNST3; and (2) MeWOX4.1 and MeWOX4.2 as the potential cassava orthologues of the Arabidopsis cambium regulator AtWOX4. Fibrous and storage roots were anatomically characterised and tested for the expression of the identified genes. Results revealed that (1) MeVND7.1 and MeVND7.2 are expressed in the fibrous but not in the storage roots; (2) MeVND6 shows low expression in both root types; (3) MeNST3.1 is not expressed in the fibrous or storage roots, while MeNST3.2 is highly expressed in both root-types and (4) MeWOX4.1 and, to a higher level, MeWOX4.2 are expressed in both the fibrous and storage roots. Results open new avenues for research in cassava root development and for food security-oriented biotechnology programmes.

  16. Characterizing and mapping resistance in synthetic-derived wheat to Rhizoctonia root rot in a green bridge environment

    USDA-ARS?s Scientific Manuscript database

    Root rot caused by Rhizoctonia species is an economically important soilborne disease of spring planted wheat in growing regions of the Pacific Northwest (PNW). The main method of controlling the disease currently is through tillage, which deters farmers from adopting the benefits of minimal tillage...

  17. Wilt, crown, and root rot of common rose mallow (Hibiscus moscheutos) caused by a novel Fusarium sp

    USDA-ARS?s Scientific Manuscript database

    A new crown and root rot disease of landscape plantings of the malvaceous ornamental common rose mallow (Hibiscus moscheutos) was first detected in Washington State in 2012. The main objectives of this study were to complete Koch's postulates, document the disease sypmtoms photographically, and iden...

  18. Unraveling complex viral infections in cassava (Manihot esculenta Crantz) from Colombia.

    PubMed

    Carvajal-Yepes, Monica; Olaya, Cristian; Lozano, Ivan; Cuervo, Maritza; Castaño, Mauricio; Cuellar, Wilmer J

    2014-06-24

    In the Americas, different disease symptoms have been reported in cassava including leaf mosaics, vein clearings, mottles, ring spots, leaf distortions and undeveloped and deformed storage roots. Some viruses have been identified and associated with these symptoms while others have been reported in symptomless plants or latent infections. We observed that reoviruses associated with severe root symptoms (RS) of Cassava Frogskin Disease (CFSD) are not associated with leaf symptoms (LS) observed in the cassava indicator plant 'Secundina'. Neither were these LS associated with the previously characterized Cassava common mosaic virus, Cassava virus X, Cassava vein mosaic virus or phytoplasma, suggesting the presence of additional pathogens. In order to explain LS observed in cassava we used a combination of biological, serological and molecular tests. Here, we report three newly described viruses belonging to the families Secoviridae, Alphaflexiviridae and Luteoviridae found in cassava plants showing severe RS associated with CFSD. All tested plants were infected by a mix of viruses that induced distinct LS in 'Secundina'. Out of the three newly described viruses, a member of family Secoviridae could experimentally induce LS in single infection. Our results confirm the common occurrence of complex viral infections in cassava field-collected since the 1980s. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Genome-Wide Analyses of Calcium Sensors Reveal Their Involvement in Drought Stress Response and Storage Roots Deterioration after Harvest in Cassava.

    PubMed

    Hu, Wei; Yan, Yan; Tie, Weiwei; Ding, Zehong; Wu, Chunlai; Ding, Xupo; Wang, Wenquan; Xia, Zhiqiang; Guo, Jianchun; Peng, Ming

    2018-04-19

    Calcium (Ca 2+ ) plays a crucial role in plant development and responses to environmental stimuli. Currently, calmodulins (CaMs), calmodulin-like proteins (CMLs), and calcineurin B-like proteins (CBLs), such as Ca 2+ sensors, are not well understood in cassava ( Manihot esculenta Crantz), an important tropical crop. In the present study, 8 CaMs, 48 CMLs, and 9 CBLs were genome-wide identified in cassava, which were divided into two, four, and four groups, respectively, based on evolutionary relationship, protein motif, and gene structure analyses. Transcriptomic analysis revealed the expression diversity of cassava CaMs-CMLs-CBLs in distinct tissues and in response to drought stress in different genotypes. Generally, cassava CaMs-CMLs-CBLs showed different expression profiles between cultivated varieties (Arg7 and SC124) and wild ancestor (W14) after drought treatment. In addition, numerous CaMs-CMLs-CBLs were significantly upregulated at 6 h, 12 h, and 48 h after harvest, suggesting their possible role during storage roots (SR) deterioration. Further interaction network and co-expression analyses suggested that a CBL-mediated interaction network was widely involved in SR deterioration. Taken together, this study provides new insights into CaMs-CMLs-CBLs-mediated drought adaption and SR deterioration at the transcription level in cassava, and identifies some candidates for the genetic improvement of cassava.

  20. Development and application of transgenic technologies in cassava.

    PubMed

    Taylor, Nigel; Chavarriaga, Paul; Raemakers, Krit; Siritunga, Dimuth; Zhang, Peng

    2004-11-01

    The capacity to integrate transgenes into the tropical root crop cassava (Manihot esculenta Crantz) is now established and being utilized to generate plants expressing traits of agronomic interest. The tissue culture and gene transfer systems currently employed to produce these transgenic cassava have improved significantly over the past 5 years and are assessed and compared in this review. Programs are underway to develop cassava with enhanced resistance to viral diseases and insects pests, improved nutritional content, modified and increased starch metabolism and reduced cyanogenic content of processed roots. Each of these is described individually for the underlying biology the molecular strategies being employed and progress achieved towards the desired product. Important advances have occurred, with transgenic plants from several laboratories being prepared for field trails.

  1. QTL analysis of Fusarium root rot resistance in an Andean x Middle American common bean RIL population

    USDA-ARS?s Scientific Manuscript database

    Aims Fusarium root rot (FRR) is a soil-borne disease that constrains common bean (Phaseolus vulgaris L.) production. FRR causal pathogens include clade 2 members of the Fusarium solani species complex. Here we characterize common bean reaction to four Fusarium species and identify genomic regions as...

  2. Cassava brown streak disease in Rwanda, the associated viruses and disease phenotypes.

    PubMed

    Munganyinka, E; Ateka, E M; Kihurani, A W; Kanyange, M C; Tairo, F; Sseruwagi, P; Ndunguru, J

    2018-02-01

    Cassava brown streak disease (CBSD) was first observed on cassava ( Manihot esculenta ) in Rwanda in 2009. In 2014 eight major cassava-growing districts in the country were surveyed to determine the distribution and variability of symptom phenotypes associated with CBSD, and the genetic diversity of cassava brown streak viruses. Distribution of the CBSD symptom phenotypes and their combinations varied greatly between districts, cultivars and their associated viruses. The symptoms on leaf alone recorded the highest (32.2%) incidence, followed by roots (25.7%), leaf + stem (20.3%), leaf + root (10.4%), leaf + stem + root (5.2%), stem + root (3.7%), and stem (2.5%) symptoms. Analysis by RT-PCR showed that single infections of Ugandan cassava brown streak virus (UCBSV) were most common (74.2% of total infections) and associated with all the seven phenotypes studied. Single infections of Cassava brown streak virus (CBSV) were predominant (15.3% of total infections) in CBSD-affected plants showing symptoms on stems alone. Mixed infections (CBSV + UCBSV) comprised 10.5% of total infections and predominated in the combinations of leaf + stem + root phenotypes. Phylogenetic analysis and the estimates of evolutionary divergence, using partial sequences (210 nt) of the coat protein gene, revealed that in Rwanda there is one type of CBSV and an indication of diverse UCBSV. This study is the first to report the occurrence and distribution of both CBSV and UCBSV based on molecular techniques in Rwanda.

  3. Isolation and characterization of the promoter sequence of a cassava gene coding for Pt2L4, a glutamic acid-rich protein differentially expressed in storage roots.

    PubMed

    de Souza, C R; Aragão, F J; Moreira, E C O; Costa, C N M; Nascimento, S B; Carvalho, L J

    2009-03-24

    Cassava is one of the most important tropical food crops for more than 600 million people worldwide. Transgenic technologies can be useful for increasing its nutritional value and its resistance to viral diseases and insect pests. However, tissue-specific promoters that guarantee correct expression of transgenes would be necessary. We used inverse polymerase chain reaction to isolate a promoter sequence of the Mec1 gene coding for Pt2L4, a glutamic acid-rich protein differentially expressed in cassava storage roots. In silico analysis revealed putative cis-acting regulatory elements within this promoter sequence, including root-specific elements that may be required for its expression in vascular tissues. Transient expression experiments showed that the Mec1 promoter is functional, since this sequence was able to drive GUS expression in bean embryonic axes. Results from our computational analysis can serve as a guide for functional experiments to identify regions with tissue-specific Mec1 promoter activity. The DNA sequence that we identified is a new promoter that could be a candidate for genetic engineering of cassava roots.

  4. Integrated options for the management of black root rot of strawberry caused by Rhizoctonia solani Kuhn.

    PubMed

    Asad-Uz-Zaman, Md; Bhuiyan, Mohammad Rejwan; Khan, Mohammad Ashik Iqbal; Alam Bhuiyan, Md Khurshed; Latif, Mohammad Abdul

    2015-02-01

    An investigation was made to manage strawberry black root rot caused by Rhizoctonia solani (R. solani) through the integration of Trichoderma harzianum (T. harzianum) isolate STA7, mustard oil cake and Provax 200. A series of preliminary experiments were conducted to select a virulent isolate of R. solani, an effective isolate of T. harzianum, a suitable organic amendment, and a suitable fungicide before setting the experiment for integration. The pathogenicity of the selected four isolates of R. solani was evaluated against strawberry and isolate SR1 was selected as the test pathogen due to its highest virulent (95.47% mortality) characteristics. Among the 20 isolates of T. harzianum, isolate STA7 showed maximum inhibition (71.97%) against the test pathogen (R. solani). Among the fungicides, Provax-200 was found to be more effective at lowest concentration (100 ppm) and highly compatible with Trichoderma isolates STA7. In the case of organic amendments, maximum inhibition (59.66%) of R. solani was obtained through mustard oil cake at the highest concentration (3%), which was significantly superior to other amendments. Minimum percentages of diseased roots were obtained with pathogen (R. solani)+Trichoderma+mustard oil cake+Provax-200 treatment, while the highest was observed with healthy seedlings with a pathogen-inoculated soil. In the case of leaf and fruit rot diseases, significantly lowest infected leaves as well as fruit rot were observed with a pathogen+Trichoderma+mustard oil cake+Provax-200 treatment in comparison with the control. A similar trend of high effectiveness was observed by the integration of Trichoderma, fungicide and organic amendments in controlling root rot and fruit diseases of strawberry. Single application of Trichoderma isolate STA7, Provax 200 or mustard oil cake did not show satisfactory performance in terms of disease-free plants, but when they were applied in combination, the number of healthy plants increased significantly. The

  5. Composition, structure, physicochemical properties, and modifications of cassava starch.

    PubMed

    Zhu, Fan

    2015-05-20

    Cassava is highly tolerant to harsh climatic conditions and has great productivity on marginal lands. The supply of cassava starch, the major component of the root, is thus sustainable and cheap. This review summarizes the current knowledge of the composition, physical and chemical structures, physicochemical properties, nutritional quality, and modifications of cassava starch. Research opportunities to better understand this starch are provided. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Spatial Distribution of Root and Crown Rot Fungi Associated With Winter Wheat in the North China Plain and Its Relationship With Climate Variables

    PubMed Central

    Xu, Fei; Yang, Gongqiang; Wang, Junmei; Song, Yuli; Liu, Lulu; Zhao, Kai; Li, Yahong; Han, Zihang

    2018-01-01

    The distribution frequency of pathogenic fungi associated with root and crown rot of winter wheat (Triticum aestivum) from 104 fields in the North China Plain was determined during the period from 2013 to 2016. The four most important species identified were Bipolaris sorokiniana (24.0% from roots; 33.7% from stems), Fusarium pseudograminearum (14.9% from roots; 27.8% from stems), Rhizoctonia cerealis (1.7% from roots; 4.4% from stems), and Gaeumannomyces graminis var. tritici (9.8% from roots; 4.4% from stems). We observed that the recovered species varied with the agronomic zone. Fusarium pseudograminearum was predominant in regions 1 and 3, whereas F. graminearum, F. acuminatum, and R. cerealis were predominant in regions 2 and 4. The incidence of F. pseudograminearum and R. cerealis was significantly different between regions 1 and 4, while no significant association was found in the distribution of the other species and the agronomic zones. A negative correlation between the frequency of occurrence of F. pseudograminearum and mean annual precipitation during 2013–2016 (r = −0.71; P < 0.01) in the North China Plain and a positive correlation between the mean annual precipitation during 2013–2016 and the frequency of occurrence of F. asiaticum (r = 0.74; P < 0.01) were observed. Several Fusarium species were also found with low frequencies of ~2.1%−3.4 % (F. graminearum, F. acuminatum, and F. sinensis) and ~0.1%−1.3% (F. equiseti, F. oxysporum, F. proliferatum, F. culmorum, F. avenaceum, and F. asiaticum). In more than 93% of the fields, from the root and crown tissues of wheat, two or more root and crown rot species were isolated. The coexistence of Fusarium spp. and B. sorokiniana in one field (65.4%) or in individual plants (11.6%) was more common than for the other species combinations. Moreover, this is the first report on the association between F. sinensis and root and crown rot of wheat. Our results would be useful in the framing guidelines for

  7. Transcriptional Response of Virus-Infected Cassava and Identification of Putative Sources of Resistance for Cassava Brown Streak Disease

    PubMed Central

    Maruthi, M. N.; Bouvaine, Sophie; Tufan, Hale A.; Mohammed, Ibrahim U.; Hillocks, Rory J.

    2014-01-01

    Cassava (Manihot esculenta) is a major food staple in sub-Saharan Africa, which is severely affected by cassava brown streak disease (CBSD). The aim of this study was to identify resistance for CBSD as well as to understand the mechanism of putative resistance for providing effective control for the disease. Three cassava varieties; Kaleso, Kiroba and Albert were inoculated with cassava brown streak viruses by grafting and also using the natural insect vector the whitefly, Bemisia tabaci. Kaleso expressed mild or no disease symptoms and supported low concentrations of viruses, which is a characteristic of resistant plants. In comparison, Kiroba expressed severe leaf but milder root symptoms, while Albert was susceptible with severe symptoms both on leaves and roots. Real-time PCR was used to estimate virus concentrations in cassava varieties. Virus quantities were higher in Kiroba and Albert compared to Kaleso. The Illumina RNA-sequencing was used to further understand the genetic basis of resistance. More than 700 genes were uniquely overexpressed in Kaleso in response to virus infection compared to Albert. Surprisingly, none of them were similar to known resistant gene orthologs. Some of the overexpressed genes, however, belonged to the hormone signalling pathways and secondary metabolites, both of which are linked to plant resistance. These genes should be further characterised before confirming their role in resistance to CBSD. PMID:24846209

  8. Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L.) and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress.

    PubMed

    Egamberdieva, Dilfuza; Wirth, Stephan J; Shurigin, Vyacheslav V; Hashem, Abeer; Abd Allah, Elsayed F

    2017-01-01

    Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non-rhizobial endophytic bacteria from the root nodules of chickpea ( Cicer arietinum L.), and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1 , Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H 2 O 2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani . This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress.

  9. Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L.) and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress

    PubMed Central

    Egamberdieva, Dilfuza; Wirth, Stephan J.; Shurigin, Vyacheslav V.; Hashem, Abeer; Abd_Allah, Elsayed F.

    2017-01-01

    Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non–rhizobial endophytic bacteria from the root nodules of chickpea (Cicer arietinum L.), and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1, Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H2O2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani. This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress. PMID:29033922

  10. Conjunctively screening of biocontrol agents (BCAs) against fusarium root rot and fusarium head blight caused by Fusarium graminearum.

    PubMed

    Wang, Lu-Yao; Xie, Yue-Shen; Cui, Yuan-Yu; Xu, Jianjun; He, Wei; Chen, Huai-Gu; Guo, Jian-Hua

    2015-08-01

    Fusarium root-rot and fusarium head blight are plant diseases caused by Fusarium sp. in different growth periods of wheat, bring heavy losses to crop production in China. This research is aiming to screen biocontrol agents conjunctively for controlling these two diseases at the same time, as well as evaluate our previous BCAs (Biological Control Agents) screening strategies in more complex situation, considering biocontrol is well concerned as an environmental-friendly plant disease controlling method. Totally 966 bacterial isolates were screened from different parts of wheat tissues, of which potential biocontrol values were detected according to their abilities in antagonism inhibition and secreting extracellular hydrolytic enzyme. Biocontrol tests against fusarium root rot and fusarium head blight were carried out on 37 bacterial isolates with potential biocontrol capacity after pre-selection through ARDRA- and BOX-PCR analysis on strains with high assessment points. We acquired 10 BCAs with obvious biocontrol efficacy (more than 40%) in greenhouse and field tests. Pseudomonas fluorescens LY1-8 performed well in both two tests (biocontrol efficacy: 44.62% and 58.31%), respectively. Overall, correlation coefficient is 0.720 between assessment values of 37 tested BCA strains and their biocontrol efficacy in trails against fusarium root rot; correlation coefficient is 0.806 between their assessment values and biocontrol efficacy in trails against fusarium head blight. We acquired 10 well-performed potential BCAs, especially P. fluorescens LY1-8 displayed good biocontrol capacity against two different diseases on wheat. Biocontrol efficacies results in both greenhouse and field tests showed high positive correlation with assessment values (0.720 and 0.806), suggesting that the BCAs screening and assessing strategy previously developed in our lab is also adaptable for conjunctively screening BCAs for controlling both root and shoot diseases on wheat caused by same

  11. Development of cassava periclinal chimera may boost production.

    PubMed

    Bomfim, N; Nassar, N M A

    2014-02-10

    Plant periclinal chimeras are genotypic mosaics arranged concentrically. Trials to produce them to combine different species have been done, but pratical results have not been achieved. We report for the second time the development of a very productive interspecific periclinal chimera in cassava. It has very large edible roots up to 14 kg per plant at one year old compared to 2-3 kg in common varieties. The epidermal tissue formed was from Manihot esculenta cultivar UnB 032, and the subepidermal and internal tissue from the wild species, Manihot fortalezensis. We determined the origin of tissues by meiotic and mitotic chromosome counts, plant anatomy and morphology. Epidermal features displayed useful traits to deduce tissue origin: cell shape and size, trichome density and stomatal length. Chimera roots had a wholly tuberous and edible constitution with smaller starch granule size and similar distribution compared to cassava. Root size enlargement might have been due to an epigenetic effect. These results suggest a new line of improved crop based on the development of interspecific chimeras composed of different combinations of wild and cultivated species. It promises boosting cassava production through exceptional root enlargement.

  12. Geospatial association of endemicity of ataxic polyneuropathy and highly cyanogenic cassava cultivars.

    PubMed

    Oluwole, Olusegun Steven Ayodele; Oludiran, Adeyinka

    2013-09-14

    Exposure to cyanide from cassava foods is present in communities where ataxic polyneuropathy is endemic. Ataxic polyneuropathy is endemic in coastal parts of southwest and southeast Nigeria, and coastal Newala, south India, but it has been reported in epidemic or endemic forms from Africa, Asia, or Caribbean. This study was done to determine if cyanogenicity of cassava cultivars is higher in lowland than highland areas, and if areas of endemicity of ataxic polyneuropathy colocalize with areas of highest cyanogenicity of cassava. Roots of cassava cultivars were collected from 150 farmers in 32 of 37 administrative areas in Nigeria. Global positioning system was used to determine the location of the roots. Roots were assayed for concentrations of cyanogens. Thin Plate Spline regression was used to produce the contour map of cyanogenicity of the study area. Contour maps of altitude of the endemic areas were produced. Relationship of cyanogenicity of cassava cultivars and altitude, and of locations of areas of high cyanogenicity and areas of endemicity were determined. Geometrical mean (95% CI) cyanogen concentration was 182 (142-233) mg HCN eq/kg dry wt for cassava cultivars in areas ≤ 25 m above sea level, but 54 (43-66) mg HCN eq/kg dry wt for areas > 375 m. Non-spatial linear regression of altitude on logarithm transformed concentrations of cyanogens showed highly significant association, (p < 0.0001). Contour map of concentrations of cyanogens in cassava cultivars in Nigeria showed four areas with average concentrations of cassava cyanogens > 250 mg HCN eq/kg dry wt, and one area of moderately high cyanogen concentration > 150 mg HCN eq/kg dry wt. The endemic areas colocalized with areas of highest cassava cyanogenicity in lowland areas close to the Atlantic Ocean. This study shows strong geospatial association of areas of endemicity of ataxic polyneuropathy and areas of highest cyanogenicity of cassava cultivars. Finding of higher

  13. Cassava as a food.

    PubMed

    Okezie, B O; Kosikowski, F V

    1982-01-01

    This review has attempted to examine information pertaining to the role of cassava (Manihot esculenta) as a major food source for a large part of the world population, particularly the countries of South America, Africa, and Asia, where it is primarily a major source of energy for 300 to 500 million people. Its cultivation, usually on small farms with little technology, is estimated to cover on an annual basis about 11 million hectares providing about 105 million tons, more than half of which is consumed by humans. The importance of cassava as an energy source can be seen by its growing demand in the European economic community countries where it forms up to 60% of the balanced diets for swine. Cassava is one of the crops that converts the greatest amount of solar energy into soluble carbohydrates per unit of area, thus 1 kg of moisture-free cassava meal may yield up to about 3750 kcal which would mean that a yearly production of 15 tons of cassava meal per hectare would yield some 56 million kcal. The major limitations of cassava as food appear to be its poor protein content and quality and the rapid post harvest deterioration of its roots which usually prevents their storage in the fresh state for more than a few days. However, in addition to its use for culinary purposes, cassava finds application in industrial products such as an adhesive for laundry purposes, for manufacturing paper, alcohol, butanol, dextrin, adhesive tape, textile sizing, and glue.

  14. Cassava; African perspective on space agriculture

    NASA Astrophysics Data System (ADS)

    Katayama, Naomi; Njemanze, Philip; Nweke, Felix; Space Agriculture Task Force, J.; Katayama, Naomi; Yamashita, Masamichi

    Looking on African perspective in space agriculture may contribute to increase diversity, and enforce robustness for advanced life support capability. Cassava, Manihot esculentaand, is one of major crop in Africa, and could be a candidate of space food materials. Since resource is limited for space agriculture in many aspects, crop yield should be high in efficiency, and robust as well. The efficiency is measured by farming space and time. Harvest yield of cassava is about 41 MJ/ m2 (70 ton/ha) after 11 months of farming. Among rice, wheat, potato, and sweet potato, cassava is ranked to the first place (40 m2 ) in terms of farming area required to supply energy of 5 MJ/day, which is recommended for one person. Production of cassava could be made under poor condition, such as acidic soil, shortage of fertilizer, draught. Laterite, similar to Martian regolith. Propagation made by stem cutting is an advantage of cassava in space agriculture avoiding entomophilous or anemophilous process to pollinate. Feature of crop storage capability is additional factor that determines the efficiency in the whole process of agriculture. Cassava root tuber can be left in soil until its consumption. Cassava might be an African contribution to space agriculture.

  15. Biological control of Rhizoctonia root rot on bean by phenazine- and cyclic lipopeptide-producing Pseudomonas CMR12a

    USDA-ARS?s Scientific Manuscript database

    Pseudomonas CMR12a was previously selected as an efficient biocontrol strain producing phenazines and cyclic lipopeptides (CLPs). In this study, biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot of bean and the involvement of phenazines and CLPs in this ability were tested. Two ...

  16. A novel, multiplexed, probe-based quantitative PCR assay for the soybean root- and stem-rot pathogen, Phytophthora sojae, utilizes its transposable element

    USDA-ARS?s Scientific Manuscript database

    Phytophthora root rot of soybean (Glycine max Merr.) is caused by the oomycete Phytophthora sojae (Kaufm. and Gerd.). P. sojae has a narrow host range, consisting primarily of soybean, and it is a serious pathogen worldwide. It exists in root and stem tissues as mycelium, wherein it can form oospo...

  17. Domestication Syndrome Is Investigated by Proteomic Analysis between Cultivated Cassava (Manihot esculenta Crantz) and Its Wild Relatives.

    PubMed

    An, Feifei; Chen, Ting; Stéphanie, Djabou Mouafi Astride; Li, Kaimian; Li, Qing X; Carvalho, Luiz J C B; Tomlins, Keith; Li, Jun; Gu, Bi; Chen, Songbi

    2016-01-01

    Cassava (Manihot esculenta Crantz) wild relatives remain a largely untapped potential for genetic improvement. However, the domestication syndrome phenomena from wild species to cultivated cassava remain poorly understood. The analysis of leaf anatomy and photosynthetic activity showed significantly different between cassava cultivars SC205, SC8 and wild relative M. esculenta ssp. Flabellifolia (W14). The dry matter, starch and amylose contents in the storage roots of cassava cultivars were significantly more than that in wild species. In order to further reveal the differences in photosynthesis and starch accumulation of cultivars and wild species, the globally differential proteins between cassava SC205, SC8 and W14 were analyzed using 2-DE in combination with MALDI-TOF tandem mass spectrometry. A total of 175 and 304 proteins in leaves and storage roots were identified, respectively. Of these, 122 and 127 common proteins in leaves and storage roots were detected in SC205, SC8 and W14, respectively. There were 11, 2 and 2 unique proteins in leaves, as well as 58, 9 and 12 unique proteins in storage roots for W14, SC205 and SC8, respectively, indicating proteomic changes in leaves and storage roots between cultivated cassava and its wild relatives. These proteins and their differential regulation across plants of contrasting leaf morphology, leaf anatomy pattern and photosynthetic related parameters and starch content could contribute to the footprinting of cassava domestication syndrome. We conclude that these global protein data would be of great value to detect the key gene groups related to cassava selection in the domestication syndrome phenomena.

  18. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus

    PubMed Central

    Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-01-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen. PMID:26539045

  19. Genome Sequence of Phytomonas françai, a Cassava (Manihot esculenta) Latex Parasite.

    PubMed

    Butler, Claire E; Jaskowska, Eleanor; Kelly, Steven

    2017-01-12

    Here, we report the genome sequence of the cassava (Manihot esculenta) latex parasite Phytomonas françai P. françai infection is linked with the yield-loss disease "chochamento de raizes" (empty roots) in the Unha variety of cassava, a disease characterized by poor root development and chlorosis of the leaves. Copyright © 2017 Butler et al.

  20. Genome Sequence of Phytomonas françai, a Cassava (Manihot esculenta) Latex Parasite

    PubMed Central

    Butler, Claire E.; Jaskowska, Eleanor

    2017-01-01

    ABSTRACT Here, we report the genome sequence of the cassava (Manihot esculenta) latex parasite Phytomonas françai. P. françai infection is linked with the yield-loss disease “chochamento de raizes” (empty roots) in the Unha variety of cassava, a disease characterized by poor root development and chlorosis of the leaves. PMID:28082482

  1. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava.

    PubMed

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-02-25

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment.

  2. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava

    PubMed Central

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-01-01

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment. PMID:26927071

  3. Cassava chip (Manihot esculenta Crantz) as an energy source for ruminant feeding.

    PubMed

    Wanapat, Metha; Kang, Sungchhang

    2015-12-01

    Cassava ( Manihot esculenta Crantz) is widely grown in sub-tropical and tropical areas, producing roots as an energy source while the top biomass including leaves and immature stems can be sun-dried and used as cassava hay. Cassava roots can be processed as dried chip or pellet. It is rich in soluble carbohydrate (75 to 85%) but low in crude protein (2 to 3%). Its energy value is comparable to corn meal but has a relatively higher rate of rumen degradation. Higher levels of non-protein nitrogen especially urea (1 to 4%) can be successfully incorporated in concentrates containing cassava chip as an energy source. Cassava chip can also be processed with urea and other ingredients (tallow, sulfur, raw banana meal, cassava hay, and soybean meal) to make products such as cassarea, cassa-ban, and cassaya. Various studies have been conducted in ruminants using cassava chip to replace corn meal in the concentrate mixtures and have revealed satisfactory results in rumen fermentation efficiency and the subsequent production of meat and milk. In addition, it was advantageous when used in combination with rice bran in the concentrate supplement. Practical home-made-concentrate using cassava chip can be easily prepared for use on farms. A recent development has involved enriching protein in cassava chips, yielding yeast fermented cassava chip protein (YEFECAP) of up to 47.5% crude protein, which can be used to replace soybean meal. It is therefore, recommended to use cassava chip as an alternative source of energy to corn meal when the price is economical and it is locally available.

  4. Effect of cultural practices and fungicide treatments on the severity of Phytophthora root rot of blueberries grown in Mississippi

    USDA-ARS?s Scientific Manuscript database

    Phytophthora root rot is an important disease of blueberries, especially those grown in areas with poor drainage. Reliable cultural and chemical management strategies are needed for control of this disease. Two studies were conducted to evaluate the effects of cultural practices and fungicide treat...

  5. Site-specific management of cotton root rot using airborne and high resolution satellite imagery and variable rate technology

    USDA-ARS?s Scientific Manuscript database

    Cotton root rot is a century-old cotton disease that can now be effectively controlled with Topguard Terra Fungicide. As this disease tends to occur in the same general areas within fields in recurring years, site-specific application of the fungicide only to the infested areas can be more effective...

  6. Geospatial association of endemicity of ataxic polyneuropathy and highly cyanogenic cassava cultivars

    PubMed Central

    2013-01-01

    Background Exposure to cyanide from cassava foods is present in communities where ataxic polyneuropathy is endemic. Ataxic polyneuropathy is endemic in coastal parts of southwest and southeast Nigeria, and coastal Newala, south India, but it has been reported in epidemic or endemic forms from Africa, Asia, or Caribbean. This study was done to determine if cyanogenicity of cassava cultivars is higher in lowland than highland areas, and if areas of endemicity of ataxic polyneuropathy colocalize with areas of highest cyanogenicity of cassava. Methods Roots of cassava cultivars were collected from 150 farmers in 32 of 37 administrative areas in Nigeria. Global positioning system was used to determine the location of the roots. Roots were assayed for concentrations of cyanogens. Thin Plate Spline regression was used to produce the contour map of cyanogenicity of the study area. Contour maps of altitude of the endemic areas were produced. Relationship of cyanogenicity of cassava cultivars and altitude, and of locations of areas of high cyanogenicity and areas of endemicity were determined. Results Geometrical mean (95% CI) cyanogen concentration was 182 (142–233) mg HCN eq/kg dry wt for cassava cultivars in areas ≤ 25 m above sea level, but 54 (43–66) mg HCN eq/kg dry wt for areas > 375 m. Non-spatial linear regression of altitude on logarithm transformed concentrations of cyanogens showed highly significant association, (p < 0.0001). Contour map of concentrations of cyanogens in cassava cultivars in Nigeria showed four areas with average concentrations of cassava cyanogens > 250 mg HCN eq/kg dry wt, and one area of moderately high cyanogen concentration > 150 mg HCN eq/kg dry wt. The endemic areas colocalized with areas of highest cassava cyanogenicity in lowland areas close to the Atlantic Ocean. Conclusion This study shows strong geospatial association of areas of endemicity of ataxic polyneuropathy and areas of highest cyanogenicity of

  7. Domestication syndrome in cassava (Manihot esculenta Crantz): Assessing morphological traits and differentially expressed genes associated with genetic diversity of storage root

    USDA-ARS?s Scientific Manuscript database

    Cassava is a starchy root crop that provides a staple food source for millions of people in tropical and subtropical regions of Asia, Latin America, and Africa. Brazil is considered the major center of diversification for species of the genus Manihot. It is also a center of domestication for the cul...

  8. Improvement of organoleptic quality of retted cassava products by alkali pretreatment of roots and addition of sodium nitrate during retting.

    PubMed

    Ogbo, Frank C

    2003-12-15

    Alkali pretreatment of cassava roots before retting and addition of sodium nitrate during retting were used to manipulate the metabolism of microorganisms involved in cassava (Manihot esculenta Crantz) retting, as a method for removing the characteristic offensive odour of retted cassava products. Odour was assessed by organoleptic methods. The characteristics of fermentation of cassava by the traditional method (control) were as follows; aerobic mesophilic count (APC) on nutrient agar (NA) at 30 degrees C/48 h, attained a maximum of 2.3 x 10(7)/ml retting juice while counts on de Man Rogosa and Sharpe agar (MRS) at 30 degrees C/48 h were 1.6 x 10(8)/ml. Maximum titrable acidity was 0.062% lactic acid by weight of retting juice. Cassava was retted in 3 days and the product exhibited characteristic offensive odour. Addition of NaNO3 into retting water effectively removed odour at a concentration of 0.3 g/l. Maximum APC on NA/30 degrees C/48 h was 6.8 x 10(6)/ml. Counts on MRS/30 degrees C/48 h exceeded 2.4 x 10(9)/ml. Retting was complete in 3 days with a final titrable acidity of 0.068% of retting juice. Removal of odour likely resulted from selection of homo-fermentative lactic acid bacteria, thus producing mostly odourless lactic acid. Alkali pretreatment of roots before retting was efficacious in removing odour at a concentration of 10 g/l for 30 min. This fermentation was characterized by APC on NA/30 degrees C/48 h of 5.4 x 10(6)/ml; MRS/30 degrees C/48 h reached a maximum of only 10 x 10(4)/ml and correspondingly low titrable acidity of 0.003%. Low counts of lactic acid bacteria correlate well with the absence of odour in this sample. Both treatments did not adversely affect the detoxification process, yielding "foo-foo" with HCN levels lower than 10 mg/kg. Residual nitrates and nitrites of 30 mg/kg in the sodium nitrate-treated sample were also within the safe limits of 156 mg/kg allowed in many countries. Organoleptically improved samples were acceptable to

  9. Gene Co-Expression Analysis Inferring the Crosstalk of Ethylene and Gibberellin in Modulating the Transcriptional Acclimation of Cassava Root Growth in Different Seasons

    PubMed Central

    Saithong, Treenut; Saerue, Samorn; Kalapanulak, Saowalak; Sojikul, Punchapat; Narangajavana, Jarunya; Bhumiratana, Sakarindr

    2015-01-01

    Cassava is a crop of hope for the 21st century. Great advantages of cassava over other crops are not only the capacity of carbohydrates, but it is also an easily grown crop with fast development. As a plant which is highly tolerant to a poor environment, cassava has been believed to own an effective acclimation process, an intelligent mechanism behind its survival and sustainability in a wide range of climates. Herein, we aimed to investigate the transcriptional regulation underlying the adaptive development of a cassava root to different seasonal cultivation climates. Gene co-expression analysis suggests that AP2-EREBP transcription factor (ERF1) orthologue (D142) played a pivotal role in regulating the cellular response to exposing to wet and dry seasons. The ERF shows crosstalk with gibberellin, via ent-Kaurene synthase (D106), in the transcriptional regulatory network that was proposed to modulate the downstream regulatory system through a distinct signaling mechanism. While sulfur assimilation is likely to be a signaling regulation for dry crop growth response, calmodulin-binding protein is responsible for regulation in the wet crop. With our initiative study, we hope that our findings will pave the way towards sustainability of cassava production under various kinds of stress considering the future global climate change. PMID:26366737

  10. Gene Co-Expression Analysis Inferring the Crosstalk of Ethylene and Gibberellin in Modulating the Transcriptional Acclimation of Cassava Root Growth in Different Seasons.

    PubMed

    Saithong, Treenut; Saerue, Samorn; Kalapanulak, Saowalak; Sojikul, Punchapat; Narangajavana, Jarunya; Bhumiratana, Sakarindr

    2015-01-01

    Cassava is a crop of hope for the 21st century. Great advantages of cassava over other crops are not only the capacity of carbohydrates, but it is also an easily grown crop with fast development. As a plant which is highly tolerant to a poor environment, cassava has been believed to own an effective acclimation process, an intelligent mechanism behind its survival and sustainability in a wide range of climates. Herein, we aimed to investigate the transcriptional regulation underlying the adaptive development of a cassava root to different seasonal cultivation climates. Gene co-expression analysis suggests that AP2-EREBP transcription factor (ERF1) orthologue (D142) played a pivotal role in regulating the cellular response to exposing to wet and dry seasons. The ERF shows crosstalk with gibberellin, via ent-Kaurene synthase (D106), in the transcriptional regulatory network that was proposed to modulate the downstream regulatory system through a distinct signaling mechanism. While sulfur assimilation is likely to be a signaling regulation for dry crop growth response, calmodulin-binding protein is responsible for regulation in the wet crop. With our initiative study, we hope that our findings will pave the way towards sustainability of cassava production under various kinds of stress considering the future global climate change.

  11. Domestication Syndrome Is Investigated by Proteomic Analysis between Cultivated Cassava (Manihot esculenta Crantz) and Its Wild Relatives

    PubMed Central

    An, Feifei; Chen, Ting; Stéphanie, Djabou Mouafi Astride; Li, Kaimian; Li, Qing X.; Carvalho, Luiz J. C. B.; Tomlins, Keith; Li, Jun; Gu, Bi; Chen, Songbi

    2016-01-01

    Cassava (Manihot esculenta Crantz) wild relatives remain a largely untapped potential for genetic improvement. However, the domestication syndrome phenomena from wild species to cultivated cassava remain poorly understood. The analysis of leaf anatomy and photosynthetic activity showed significantly different between cassava cultivars SC205, SC8 and wild relative M. esculenta ssp. Flabellifolia (W14). The dry matter, starch and amylose contents in the storage roots of cassava cultivars were significantly more than that in wild species. In order to further reveal the differences in photosynthesis and starch accumulation of cultivars and wild species, the globally differential proteins between cassava SC205, SC8 and W14 were analyzed using 2-DE in combination with MALDI-TOF tandem mass spectrometry. A total of 175 and 304 proteins in leaves and storage roots were identified, respectively. Of these, 122 and 127 common proteins in leaves and storage roots were detected in SC205, SC8 and W14, respectively. There were 11, 2 and 2 unique proteins in leaves, as well as 58, 9 and 12 unique proteins in storage roots for W14, SC205 and SC8, respectively, indicating proteomic changes in leaves and storage roots between cultivated cassava and its wild relatives. These proteins and their differential regulation across plants of contrasting leaf morphology, leaf anatomy pattern and photosynthetic related parameters and starch content could contribute to the footprinting of cassava domestication syndrome. We conclude that these global protein data would be of great value to detect the key gene groups related to cassava selection in the domestication syndrome phenomena. PMID:27023871

  12. Attempts to control Fusarium root rot of bean by seed dressing.

    PubMed

    Gilardi, G; Baudino, M; Gullino, M L; Garibaldi, A

    2008-01-01

    In summer 2006, a root rot caused by Fusarium oxysporum was observed in commercial farms on common bean (Phaseolus vulgaris) on the cv Billò and Borlotto. A study was undertaken in order to evaluate the efficacy of different biological control agents applied as seed dressing. In the presence of a medium-high disease incidence, among the biocontrol agents tested, Trichoderma harzianum T 22, Bacillus subtilis QST 713, followed by Pseudomonas chlororaphis, provided generally the best control. Their efficacy was also consistent in the different trials. Also the mixture of T. harzianum + T. viride provide a good disease control. Streptomyces griseoviridis and the 3 strains of Fusarim oxysporum, although less effective, provided a partial control of the disease. The fungicide mancozeb provided only a partial disease control.

  13. Cassava biology and physiology.

    PubMed

    El-Sharkawy, Mabrouk A

    2004-11-01

    Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation,which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil,thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4

  14. Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz).

    PubMed

    Adeyemo, O Sarah; Chavarriaga, Paul; Tohme, Joe; Fregene, Martin; Davis, Seth J; Setter, Tim L

    2017-01-01

    Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding.

  15. Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz)

    PubMed Central

    Adeyemo, O. Sarah; Chavarriaga, Paul; Tohme, Joe; Fregene, Martin; Davis, Seth J.

    2017-01-01

    Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding. PMID:28753668

  16. Population genomic analyses of the brown root-rot pathogen, Phellinus noxius, examine potential invasive spread among Pacific islands

    Treesearch

    Jane E. Stewart; Mee-Sook Kim; Louise Shuey; Norio Sahashi; Yuko Ota; Robert L. Schlub; Phil G. Cannon; Ned B. Klopfenstein

    2016-01-01

    Phellinus noxius (Corner) G. H. Cunn is a vastly destructive, fast-growing fungal pathogen that affects a wide range of woody hosts in pan-tropical areas, including Asia, Australia, Africa, and Oceania (Ann et al. 2002; Figure 1) . This pathogen causes brown root-rot disease on cacao, coffee, and rubber, as well as diverse fruit, nut, ornamental, and other...

  17. Occurrence of the root-rot pathogen, Fusarium commune, in forest nurseries of the midwestern and western United States

    Treesearch

    Mee-Sook Kim; Jane E. Stewart; R. Kasten Dumroese; Ned B. Klopfenstein

    2012-01-01

    Fusarium commune can cause damping-off and root rot of conifer seedlings in forest nurseries, and this pathogen has been previously reported from Oregon, Idaho, and Washington, USA. We collected Fusarium isolates from additional nurseries in the midwestern and western USA to more fully determine occurrence of this pathogen. We used DNA sequences of the mitochondrial...

  18. In field damage of high and low cyanogenic cassava due to a generalist insect herbivore Cyrtomenus bergi (Hemiptera: Cydnidae).

    PubMed

    Riis, Lisbeth; Bellotti, Anthony Charles; Castaño, Oscar

    2003-12-01

    The hypothesis that cyanogenic potential in cassava roots deters polyphagous insects in the field is relevant to current efforts to reduce or eliminate the cyanogenic potential in cassava. To test this hypothesis, experiments were conducted in the field under natural selection pressure of the polyphagous root feeder Cyrtomenus bergi Froeschner (Hemiptera: Cydnidae). A number of cassava varieties (33) as well as 13 cassava siblings and their parental clone, each representing a determined level of cyanogenic potential (CNP), were scored for damage caused by C. bergi and related to CNP and nonglycosidic cyanogens, measured as hydrogen cyanide. Additionally, 161 low-CNP varieties (< 50 ppm hydrogen cyanide, fresh weight) from the cassava germplasm core collection at Centro Internacional de Agricultura Tropical (CIAT) were screened for resistance/tolerance to C. bergi. Low root damage scores were registered at all levels of CNP. Nevertheless, CNP and yield (or root size) partly explained the damage in cassava siblings (r2 = 0.82) and different cassava varieties (r2 = 0.42), but only when mean values of damage scores were used. This relation was only significant in one of two crop cycles. A logistic model describes the underlying negative relation between CNP and damage. An exponential model describes the underlying negative relation between root size and damage. Damage, caused by C. bergi feeding, released nonglycosidic cyanogens, and an exponential model fits the underlying positive relation. Fifteen low-CNP clones were selected for potential resistance/tolerance against C. bergi.

  19. Application of chloropicrin to Douglas-fir stumps to control laminated root rot does not affect infection or growth of regeneration 16 growing seasons after treatment.

    Treesearch

    Walter G. Thies; Douglas J. Westlind

    2006-01-01

    Phellinus weirii (Murr.) Gilb. causes laminated root rot (LRR), a major disease affecting growth and survival of Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) and other commercially important conifer species throughout the Pacific Northwest. This disease is known to spread to a replacement stand by root contact between...

  20. An ordered EST catalogue and gene expression profiles of cassava (Manihot esculenta) at key growth stages.

    PubMed

    Li, You-Zhi; Pan, Ying-Hua; Sun, Chang-Bin; Dong, Hai-Tao; Luo, Xing-Lu; Wang, Zhi-Qiang; Tang, Ji-Liang; Chen, Baoshan

    2010-12-01

    A cDNA library was constructed from the root tissues of cassava variety Huanan 124 at the root bulking stage. A total of 9,600 cDNA clones from the library were sequenced with single-pass from the 5'-terminus to establish a catalogue of expressed sequence tags (ESTs). Assembly of the resulting EST sequences resulted in 2,878 putative unigenes. Blastn analysis showed that 62.6% of the unigenes matched with known cassava ESTs and the rest had no 'hits' against the cassava database in the integrative PlantGDB database. Blastx analysis showed that 1,715 (59.59%) of the unigenes matched with one or more GenBank protein entries and 1,163 (40.41%) had no 'hits'. A cDNA microarray with 2,878 unigenes was developed and used to analyze gene expression profiling of Huanan 124 at key growth stages including seedling, formation of root system, root bulking, and starch maturity. Array data analysis revealed that (1) the higher ratio of up-regulated ribosome-related genes was accompanied by a high ratio of up-regulated ubiquitin, proteasome-related and protease genes in cassava roots; (2) starch formation and degradation simultaneously occur at the early stages of root development but starch degradation is declined partially due to decrease in UDP-glucose dehydrogenase activity with root maturity; (3) starch may also be synthesized in situ in roots; (4) starch synthesis, translocation, and accumulation are also associated probably with signaling pathways that parallel Wnt, LAM, TCS and ErbB signaling pathways in animals; (5) constitutive expression of stress-responsive genes may be due to the adaptation of cassava to harsh environments during long-term evolution.

  1. Starch biosynthesis in cassava: a genome-based pathway reconstruction and its exploitation in data integration

    PubMed Central

    2013-01-01

    Background Cassava is a well-known starchy root crop utilized for food, feed and biofuel production. However, the comprehension underlying the process of starch production in cassava is not yet available. Results In this work, we exploited the recently released genome information and utilized the post-genomic approaches to reconstruct the metabolic pathway of starch biosynthesis in cassava using multiple plant templates. The quality of pathway reconstruction was assured by the employed parsimonious reconstruction framework and the collective validation steps. Our reconstructed pathway is presented in the form of an informative map, which describes all important information of the pathway, and an interactive map, which facilitates the integration of omics data into the metabolic pathway. Additionally, to demonstrate the advantage of the reconstructed pathways beyond just the schematic presentation, the pathway could be used for incorporating the gene expression data obtained from various developmental stages of cassava roots. Our results exhibited the distinct activities of the starch biosynthesis pathway in different stages of root development at the transcriptional level whereby the activity of the pathway is higher toward the development of mature storage roots. Conclusions To expand its applications, the interactive map of the reconstructed starch biosynthesis pathway is available for download at the SBI group’s website (http://sbi.pdti.kmutt.ac.th/?page_id=33). This work is considered a big step in the quantitative modeling pipeline aiming to investigate the dynamic regulation of starch biosynthesis in cassava roots. PMID:23938102

  2. Starch biosynthesis in cassava: a genome-based pathway reconstruction and its exploitation in data integration.

    PubMed

    Saithong, Treenut; Rongsirikul, Oratai; Kalapanulak, Saowalak; Chiewchankaset, Porntip; Siriwat, Wanatsanan; Netrphan, Supatcharee; Suksangpanomrung, Malinee; Meechai, Asawin; Cheevadhanarak, Supapon

    2013-08-10

    Cassava is a well-known starchy root crop utilized for food, feed and biofuel production. However, the comprehension underlying the process of starch production in cassava is not yet available. In this work, we exploited the recently released genome information and utilized the post-genomic approaches to reconstruct the metabolic pathway of starch biosynthesis in cassava using multiple plant templates. The quality of pathway reconstruction was assured by the employed parsimonious reconstruction framework and the collective validation steps. Our reconstructed pathway is presented in the form of an informative map, which describes all important information of the pathway, and an interactive map, which facilitates the integration of omics data into the metabolic pathway. Additionally, to demonstrate the advantage of the reconstructed pathways beyond just the schematic presentation, the pathway could be used for incorporating the gene expression data obtained from various developmental stages of cassava roots. Our results exhibited the distinct activities of the starch biosynthesis pathway in different stages of root development at the transcriptional level whereby the activity of the pathway is higher toward the development of mature storage roots. To expand its applications, the interactive map of the reconstructed starch biosynthesis pathway is available for download at the SBI group's website (http://sbi.pdti.kmutt.ac.th/?page_id=33). This work is considered a big step in the quantitative modeling pipeline aiming to investigate the dynamic regulation of starch biosynthesis in cassava roots.

  3. Long-term effects of stump removal to control root rot on forest soil bulk density, soil carbon and nitrogen content.

    Treesearch

    D. Zabowski; D. Chambrear; N. Rotramel; W.G. Thies

    2008-01-01

    Phellinus weirii (Mum.) Gilb is a native pathogen in the forests of the Northwestern United States causing laminated root rot and mortality in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and other susceptible conifer species. This facultative saprophyte is a natural part of the ecosystem, present in most Douglas-fir...

  4. Analysis of heterogeneity of Copia-like retrotransposons in the genome of cassava (Manihot esculenta Crantz).

    PubMed

    Gbadegesin, Micheal A; Beeching, John R

    2011-12-20

    Retrotransposons are ubiquitous in eukaryotic genomes and now proving to be useful genetic tools for genetic diversity and phylogenetic analyses, especially in plants. In order to assess the diversity of Ty1/Copia-like retrotransposons of cassava, we used PCR primers anchored on the conserved domains of reverse transcriptases (RTs) to amplify cassava Ty1/Copia-like RT. The PCR product was cloned and sequenced. Sequences analysis of the clones revealed the presence of 69 families of Ty1/Copia-like retrotransposon in the genome of cassava. Comparative analyses of the predicted amino acid sequences of these clones with those of other plants showed that retroelements of this class are very heterogeneous in cassava. Cassava is widely grown for its edible roots in the tropical and subtropical regions of the world. Cassava roots, though poor in protein, are rich in starch (makes up about 80% of the dry matter), vitamin C, carotenes, calcium and potassium. It has a great commercial importance as a source of starch and starch based products. Realizing the importance of cassava, it stands out as a crop to benefit from biotechnology development. Heterogeneity of Mecops (Manihot esculenta copia-like Retrotransposons) showed that they may be useful for genetic diversity and phylogenetic analyses of cassava germplasm.

  5. Genetic architecture and evolution of the mating type locus in fusaria that cause soybean sudden death syndrome and bean root rot

    USDA-ARS?s Scientific Manuscript database

    Fusarium tucumaniae is the only known sexually reproducing species among the seven closely related fusaria that cause soybean sudden death syndrome (SDS) or bean root rot (BRR). Laboratory mating of F. tucumaniae required two mating-compatible strains, indicating that it is heterothallic. To assess ...

  6. Beauveria bassiana and Metarhizium anisopliae endophytically colonize cassava roots following soil drench inoculation

    USDA-ARS?s Scientific Manuscript database

    The fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae were investigated to determine if endophytic colonization could be achieved in cassava. An inoculation method based on drenching the soil around cassava stems using conidial suspensions resulted in endophytic colonization of ca...

  7. Genetic diversity of root anatomy in wild and cultivated Manihot species.

    PubMed

    Bomfim, N N; Graciano-Ribeiro, D; Nassar, N M A

    2011-04-05

    An anatomical study of roots was conducted on two wild Manihot species, namely M. glaziovii and M. fortalezensis, and two cassava varieties, M. esculenta Crantz variety UnB 201 and M. esculenta variety UnB 122, to identify taxonomic differences in primary growth. Anatomical characters of cassava roots have been rarely investigated. Their study may help cassava breeders to identify varieties with economically important characters, such as tolerance to drought. We investigated tap and lateral adventitious roots of two specimens of each clone or species. Free-hand cross-sections of roots were drawn; these had been clarified with 20% sodium hypochlorite solution, stained with 1% safranin-alcian blue ethanolic solution, dehydrated in ethanol series and butyl acetate and mounted in synthetic resin. Anatomical differences among Manihot species and varieties were found in the epidermal and exodermal cell shape and wall thickness, content of cortical parenchyma, and number of xylem poles. Wall thickness of the epidermis and exodermis of tap root were similar in all species, while in the lateral root there were differences in cell shape and wall thickness. Epidermal cells with thick walls were found in the tap root of all species and in lateral roots of cassava varieties. This character is apparently associated with tolerance to drought and disease. The variation in the number of xylem poles of cassava varieties was larger (4-8) than in wild species (4-6), and appears to support the hybrid origin of cassava.

  8. The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration.

    PubMed

    Uarrota, Virgílio Gavicho; Moresco, Rodolfo; Schmidt, Eder Carlos; Bouzon, Zenilda Laurita; Nunes, Eduardo da Costa; Neubert, Enilto de Oliveira; Peruch, Luiz Augusto Martins; Rocha, Miguel; Maraschin, Marcelo

    2016-04-15

    This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with Periodic Acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Anatomic changes due to interspecific grafting in cassava (Manihot esculenta).

    PubMed

    Bomfim, N; Ribeiro, D G; Nassar, N M A

    2011-05-31

    Cassava rootstocks of varieties UnB 201 and UnB 122 grafted with scions of Manihot fortalezensis were prepared for anatomic study. The roots were cut, stained with safranin and alcian blue, and examined microscopically, comparing them with sections taken from ungrafted roots. There was a significant decrease in number of pericyclic fibers, vascular vessels and tyloses in rootstocks. They exhibited significant larger vessels. These changes in anatomic structure are a consequence of genetic effects caused by transference of genetic material from scion to rootstock. The same ungrafted species was compared. This is the first report on anatomic changes due to grafting in cassava.

  10. Cassava: a basic energy source in the tropics.

    PubMed

    Cock, J H

    1982-11-19

    Cassava (Manihot esculenta) is the fourth most important source of food energy in the tropics. More than two-thirds of the total production of this crop is used as food for humans, with lesser amounts being used for animal feed and industrial purposes. The ingestion of high levels of cassava has been associated with chronic cyanide toxicity in parts of Africa, but this appears to be related to inadequate processing of the root and poor overall nutrition. Although cassava is not a complete food it is important as a cheap source of calories. The crop has a high yield potential under good conditions, and compared to other crops it excels under suboptimal conditions, thus offering the possibility of using marginal land to increase total agricultural production. Breeding programs that bring together germ plasm from different regions coupled with improved agronomic practices can markedly increase yields. The future demand for fresh cassava may depend on improved storage methods. The markets for cassava as a substitute for cereal flours in bakery products and as an energy source in animal feed rations are likely to expand. The use of cassava as a source of ethanol for fuel depends on finding an efficient source of energy for distillation or an improved method of separating ethanol from water.

  11. Effect of Cassava on motor co-ordination and neurotransmitter level in the albino rat.

    PubMed

    Mathangi, D C; Mohan, V; Namasivayam, A

    1999-01-01

    The root of Cassava, a tropical plant, is consumed in the tropics and has been attributed as the cause for various tropical neuropathies. This study aims to discover the neurotoxic effects of chronic cassava consumption of Indian origin and the effect of malnutrition. The assessment is based on the motor co-ordination and brain neurotransmitters in rats. Cassava consumption reduced the motor co-ordination, but the changes in neurotransmitter levels due to cassava consumption (except for 5HT in corpus striatum) was identical with malnutrition-induced changes, indicating that the toxicity of chronic cassava consumption (of Indian origin) is mainly due to the associated protein calorie malnutrition (PCM).

  12. Variations in the chemical composition of cassava ( Manihot esculenta Crantz) leaves and roots as affected by genotypic and environmental variation.

    PubMed

    Burns, Anna Elizabeth; Gleadow, Roslyn Margaret; Zacarias, Anabela M; Cuambe, Constantino Estevão; Miller, Rebecca Elizabeth; Cavagnaro, Timothy Richard

    2012-05-16

    The purpose of this study was to assess the quality of cassava cultivars, in terms of cyanogenic potential and composition of macro- and micronutrients, sampled from different locations in rural Mozambique. Total cyanide concentrations in fresh cassava tissues were measured using portable cyanide testing kits, and elemental nutrients were later analyzed from dried plant tissue. Variation in cyanogenic potential and nutrient composition occurred both among cultivars and across locations. The majority of cultivars contained >100 ppm total cyanide, fresh weight, and are therefore considered to be dangerously poisonous unless adequately processed before consumption. Leaf cyanogenic and nutrient content varied with plant water status, estimated using carbon isotope discrimination (δ(13)C). The colonization of roots of all cultivars by arbuscular mycorrhizal fungi was also quantified and found to be high, indicating that mycorrhizas could play a key role in plant nutrient acquisition in these low-input farming systems.

  13. Expression pattern conferred by a glutamic acid-rich protein gene promoter in field-grown transgenic cassava (Manihot esculenta Crantz).

    PubMed

    Beltrán, J; Prías, M; Al-Babili, S; Ladino, Y; López, D; Beyer, P; Chavarriaga, P; Tohme, J

    2010-05-01

    A major constraint for incorporating new traits into cassava using biotechnology is the limited list of known/tested promoters that encourage the expression of transgenes in the cassava's starchy roots. Based on a previous report on the glutamic-acid-rich protein Pt2L4, indicating a preferential expression in roots, we cloned the corresponding gene including promoter sequence. A promoter fragment (CP2; 731 bp) was evaluated for its potential to regulate the expression of the reporter gene GUSPlus in transgenic cassava plants grown in the field. Intense GUS staining was observed in storage roots and vascular stem tissues; less intense staining in leaves; and none in the pith. Consistent with determined mRNA levels of the GUSPlus gene, fluorometric analyses revealed equal activities in root pulp and stems, but 3.5 times less in leaves. In a second approach, the activity of a longer promoter fragment (CP1) including an intrinsic intron was evaluated in carrot plants. CP1 exhibited a pronounced tissue preference, conferring high expression in the secondary phloem and vascular cambium of roots, but six times lower expression levels in leaf vascular tissues. Thus, CP1 and CP2 may be useful tools to improve nutritional and agronomical traits of cassava by genetic engineering. To date, this is the first study presenting field data on the specificity and potential of promoters for transgenic cassava.

  14. Vitamin B1 diversity and characterization of biosynthesis genes in cassava.

    PubMed

    Mangel, Nathalie; Fudge, Jared B; Fitzpatrick, Teresa B; Gruissem, Wilhelm; Vanderschuren, Hervé

    2017-06-15

    Vitamin B1, which consists of the vitamers thiamin and its phosphorylated derivatives, is an essential micronutrient for all living organisms because it is required as a metabolic cofactor in several enzymatic reactions. Genetic diversity of vitamin B1 biosynthesis and accumulation has not been investigated in major crop species other than rice and potato. We analyzed cassava germplasm for accumulation of B1 vitamers. Vitamin B1 content in leaves and roots of 41 cassava accessions showed significant variation between accessions. HPLC analyses of B1 vitamers revealed distinct profiles in cassava leaves and storage roots, with nearly equal relative levels of thiamin pyrophosphate and thiamin monophosphate in leaves, but mostly thiamin pyrophosphate in storage roots. Unusually, the cassava genome has two genes encoding the 4-amino-2-methyl-5-hydroxymethylpyrimidine phosphate synthase, THIC (MeTHIC1 and MeTHIC2), both of which carry a riboswitch in the 3'-UTR, as well as the adenylated thiazole synthase, THI1 (MeTHI1a and MeTHI1b). The THIC and THI1 genes are expressed at very low levels in storage roots compared with the accumulation of vitamin B1, indicating only limited biosynthesis de novo therein. In leaves, vitamin B1 content is negatively correlated with THIC and THI1 expression levels, suggesting post-transcriptional regulation of THIC by the riboswitch present in the 3'-UTR of the THIC mRNA and regulation of THI1 by promoter activity or alternative post-transcriptional mechanisms. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  15. Gene-based Microsatellites for Cassava (Manihot esculenta Crantz): Prevalence, Polymorphisms, and Cross-taxa Utility

    USDA-ARS?s Scientific Manuscript database

    Cassava (Manihot esculenta Crantz), a starchy root crop grown in tropical and subtropical climates, is the sixth most important crop in the world after wheat, rice, maize, potato and barley. The repertoire of simple sequence repeat (SSR) markers for cassava is limited and warrants a need for a large...

  16. Cassava: a basic energy source in the tropics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cock, J.H.

    1982-11-19

    Cassava (Manihot esculenta) is the fourth most important source of food energy in the tropics. More than two-thirds of the total production of this crop is used as food for humans, with lesser amounts being used for animal feed and industrial purposes. The ingestion of high levels of cassava has been associated with chronic cyanide toxicity in parts of Africa, but this appears to be related to inadequate processing of the root and poor overall nutrition. Although cassava is not a complete food it is important as a cheap source of calories. The crop has a high yield potential undermore » good conditions, and compared to other crops it excels under suboptimal conditions, thus offering the possibility of using marginal land to increase total agricultural production. Breeding programs that bring together germ plasm from different regions coupled with improved agronomic practices can markedly increase yields. The future demand for fresh cassava may depend on improved storage methods. The markets for cassava as a substitute for cereal flours in bakery products and as an energy source in animal feed rations are likely to expand. The use of cassava as a source of ethanol for fuel depends on finding an efficient source of energy for distillation or an improved method of separating ethanol from water. 7 figures, 8 tables.« less

  17. Cassava tissue culture and long-term preservation

    USDA-ARS?s Scientific Manuscript database

    Cassava (Manihot esculenta Crantz) is cultivated mainly for its starchy roots as an important staple food for the tropics. M. esculenta is the only cultivated species in the genus Manihot, which contains 98 species, mostly native to Brazil. In recent years several research groups have reported metho...

  18. Screening of bioagents against root rot of mung bean caused by Rhizoctonia solani.

    PubMed

    Singh, Surender; Chand, Hari

    2006-01-01

    A laboratory and green house experiment was carried out on the comparative antagonistic performance of four different bioagents (Aspergillus sp. Gliocladium virens, Trichoderma harzianum and T. viride) isolated from soil against Rhizoctonia solani. Under laboratory conditions, T. harzianum exhibited maximum (75.55%) mycelial growth inhibition of R. solani. This was followed by T. viride, which showed 65.93% mycelial growth inhibition of the pathogen. Gliocladium virens was also found to be effective antagonists, which exhibited 57.77% mycelial growth inhibition. While Aspergillus sp exhibited minimum growth inhibition (45.74%) in comparison to other bioagents. Under green house conditions, T. harzianum gave maximum protection of the disease (72.72%) followed by T. viride, which exhibited 54.54% disease control. However, G. virens and Aspergillus sp were found least effective in controlling root rot of mungbean.

  19. Rapid analyses of dry matter content and carotenoids in fresh cassava roots using a portable visible and near infrared spectrometer (Vis/NIRS).

    PubMed

    Ikeogu, Ugochukwu N; Davrieux, Fabrice; Dufour, Dominique; Ceballos, Hernan; Egesi, Chiedozie N; Jannink, Jean-Luc

    2017-01-01

    Portable Vis/NIRS are flexible tools for fast and unbiased analyses of constituents with minimal sample preparation. This study developed calibration models for dry matter content (DMC) and carotenoids in fresh cassava roots using a portable Vis/NIRS system. We examined the effects of eight data pre-treatment combinations on calibration models and assessed calibrations on processed and intact root samples. We compared Vis/NIRS derived-DMC to other phenotyping methods. The results of the study showed that the combination of standard normal variate and de-trend (SNVD) with first derivative calculated on two data points and no smoothing (SNVD+1111) was adequate for a robust model. Calibration performance was higher with processed than the intact root samples for all the traits although intact root models for some traits especially total carotenoid content (TCC) (R2c = 96%, R2cv = 90%, RPD = 3.6 and SECV = 0.63) were sufficient for screening purposes. Using three key quality traits as templates, we developed models with processed fresh root samples. Robust calibrations were established for DMC (R2c = 99%, R2cv = 95%, RPD = 4.5 and SECV = 0.9), TCC (R2c = 99%, R2cv = 91%, RPD = 3.5 and SECV = 2.1) and all Trans β-carotene (ATBC) (R2c = 98%, R2cv = 91%, RPD = 3.5 and SECV = 1.6). Coefficient of determination on independent validation set (R2p) for these traits were also satisfactory for ATBC (91%), TCC (88%) and DMC (80%). Compared to other methods, Vis/NIRS-derived DMC from both intact and processed roots had very high correlation (>0.95) with the ideal oven-drying than from specific gravity method (0.49). There was equally a high correlation (0.94) between the intact and processed Vis/NIRS DMC. Therefore, the portable Vis/NIRS could be employed for the rapid analyses of DMC and quantification of carotenoids in cassava for nutritional and breeding purposes.

  20. Suppressive Potential of Paenibacillus Strains Isolated from the Tomato Phyllosphere against Fusarium Crown and Root Rot of Tomato

    PubMed Central

    Sato, Ikuo; Yoshida, Shigenobu; Iwamoto, Yutaka; Aino, Masataka; Hyakumachi, Mitsuro; Shimizu, Masafumi; Takahashi, Hideki; Ando, Sugihiro; Tsushima, Seiya

    2014-01-01

    The suppressive potentials of Bacillus and Paenibacillus strains isolated from the tomato phyllosphere were investigated to obtain new biocontrol candidates against Fusarium crown and root rot of tomato. The suppressive activities of 20 bacterial strains belonging to these genera were examined using seedlings and potted tomato plants, and two Paenibacillus strains (12HD2 and 42NP7) were selected as biocontrol candidates against the disease. These two strains suppressed the disease in the field experiment. Scanning electron microscopy revealed that the treated bacterial cells colonized the root surface, and when the roots of the seedlings were treated with strain 42NP7 cells, the cell population was maintained on the roots for at least for 4 weeks. Although the bacterial strains had no direct antifungal activity against the causal pathogen in vitro, an increase was observed in the antifungal activities of acetone extracts from tomato roots treated with the cells of both bacterial strains. Furthermore, RT-PCR analysis verified that the expression of defense-related genes was induced in both the roots and leaves of seedlings treated with the bacterial cells. Thus, the root-colonized cells of the two Paenibacillus strains were considered to induce resistance in tomato plants, which resulted in the suppression of the disease. PMID:24920171

  1. Phenotypic approaches to drought in cassava: review

    PubMed Central

    Okogbenin, Emmanuel; Setter, Tim L.; Ferguson, Morag; Mutegi, Rose; Ceballos, Hernan; Olasanmi, Bunmi; Fregene, Martin

    2012-01-01

    Cassava is an important crop in Africa, Asia, Latin America, and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitative trait and its multigenic nature makes it very challenging to effectively manipulate and combine genes in breeding for rapid genetic gain and selection process. Cassava has a long growth cycle of 12–18 months which invariably contributes to a long breeding scheme for the crop. Modern breeding using advances in genomics and improved genotyping, is facilitating the dissection and genetic analysis of complex traits including drought tolerance, thus helping to better elucidate and understand the genetic basis of such traits. A beneficial goal of new innovative breeding strategies is to shorten the breeding cycle using minimized, efficient or fast phenotyping protocols. While high throughput genotyping have been achieved, this is rarely the case for phenotyping for drought adaptation. Some of the storage root phenotyping in cassava are often done very late in the evaluation cycle making selection process very slow. This paper highlights some modified traits suitable for early-growth phase phenotyping that may be used to reduce drought phenotyping cycle in cassava. Such modified traits can significantly complement the high throughput genotyping procedures to fast track breeding of improved drought tolerant varieties. The need for metabolite profiling, improved phenomics to take advantage of next generation sequencing technologies and high throughput phenotyping are basic steps for future direction to improve genetic gain and maximize speed for drought tolerance breeding. PMID

  2. UV-visible scanning spectrophotometry and chemometric analysis as tools for carotenoids analysis in cassava genotypes (Manihot esculenta Crantz).

    PubMed

    Moresco, Rodolfo; Uarrota, Virgílio Gavicho; Pereira, Aline; Tomazzoli, Maíra Maciel; Nunes, Eduardo da C; Peruch, Luiz Augusto Martins; Gazzola, Jussara; Costa, Christopher; Rocha, Miguel; Maraschin, Marcelo

    2015-10-21

    In this study, the metabolomics characterization focusing on the carotenoid composition of ten cassava (Manihot esculenta) genotypes cultivated in southern Brazil by UV-visible scanning spectrophotometry and reverse phase-high performance liquid chromatography was performed. Cassava roots rich in β-carotene are an important staple food for populations with risk of vitamin A deficiency. Cassava genotypes with high pro-vitamin A activity have been identified as a strategy to reduce the prevalence of deficiency of this vitamin. The data set was used for the construction of a descriptive model by chemometric analysis. The genotypes of yellow-fleshed roots were clustered by the higher concentrations of cis-β-carotene and lutein. Inversely, cream-fleshed roots genotypes were grouped precisely due to their lower concentrations of these pigments, as samples rich in lycopene (red-fleshed) differed among the studied genotypes. The analytical approach (UV-Vis, HPLC, and chemometrics) used showed to be efficient for understanding the chemodiversity of cassava genotypes, allowing to classify them according to important features for human health and nutrition.

  3. UV-visible scanning spectrophotometry and chemometric analysis as tools for carotenoids analysis in cassava genotypes (Manihot esculenta Crantz).

    PubMed

    Moresco, Rodolfo; Uarrota, Virgílio G; Pereira, Aline; Tomazzoli, Maíra; Nunes, Eduardo da C; Martins Peruch, Luiz Augusto; Gazzola, Jussara; Costa, Christopher; Rocha, Miguel; Maraschin, Marcelo

    2015-12-01

    In this study, the metabolomics characterization focusing on the carotenoid composition of ten cassava (Manihot esculenta) genotypes cultivated in southern Brazil by UV-visible scanning spectrophotometry and reverse phase-high performance liquid chromatography was performed. Cassava roots rich in β-carotene are an important staple food for populations with risk of vitamin A deficiency. Cassava genotypes with high pro-vitamin A activity have been identified as a strategy to reduce the prevalence of deficiency of this vitamin. The data set was used for the construction of a descriptive model by chemometric analysis. The genotypes of yellow-fleshed roots were clustered by the higher concentrations of cis- β-carotene and lutein. Inversely, cream-fleshed roots genotypes were grouped precisely due to their lower concentrations of these pigments, as samples rich in lycopene (redfleshed) differed among the studied genotypes. The analytical approach (UV-Vis, HPLC, and chemometrics) used showed to be efficient for understanding the chemodiversity of cassava genotypes, allowing to classify them according to important features for human health and nutrition.

  4. Field testing and exploitation of genetically modified cassava with low-amylose or amylose-free starch in Indonesia.

    PubMed

    Koehorst-van Putten, H J J; Sudarmonowati, E; Herman, M; Pereira-Bertram, I J; Wolters, A M A; Meima, H; de Vetten, N; Raemakers, C J J M; Visser, R G F

    2012-02-01

    The development and testing in the field of genetically modified -so called- orphan crops like cassava in tropical countries is still in its infancy, despite the fact that cassava is not only used for food and feed but is also an important industrial crop. As traditional breeding of cassava is difficult (allodiploid, vegetatively propagated, outbreeding species) it is an ideal crop for improvement through genetic modification. We here report on the results of production and field testing of genetically modified low-amylose transformants of commercial cassava variety Adira4 in Indonesia. Twenty four transformants were produced and selected in the Netherlands based on phenotypic and molecular analyses. Nodal cuttings of these plants were sent to Indonesia where they were grown under biosafety conditions. After two screenhouse tests 15 transformants remained for a field trial. The tuberous root yield of 10 transformants was not significantly different from the control. Starch from transformants in which amylose was very low or absent showed all physical and rheological properties as expected from amylose-free cassava starch. The improved functionality of the starch was shown for an adipate acetate starch which was made into a tomato sauce. This is the first account of a field trial with transgenic cassava which shows that by using genetic modification it is possible to obtain low-amylose cassava plants with commercial potential with good root yield and starch quality.

  5. Aggressiveness of Fusarium species and impact of root infection on growth and yield of soybeans.

    PubMed

    Arias, María M Díaz; Leandro, Leonor F; Munkvold, Gary P

    2013-08-01

    Fusarium spp. are commonly isolated from soybean roots but the pathogenic activity of most species is poorly documented. Aggressiveness and yield impact of nine species of Fusarium were determined on soybean in greenhouse (50 isolates) and field microplot (19 isolates) experiments. Root rot severity and shoot and root dry weights were compared at growth stages V3 or R1. Root systems were scanned and digital image analysis was conducted; yield was measured in microplots. Disease severity and root morphology impacts varied among and within species. Fusarium graminearum was highly aggressive (root rot severity >90%), followed by F. proliferatum and F. virguliforme. Significant variation in damping-off (20 to 75%) and root rot severity (<20 to >60%) was observed among F. oxysporum isolates. In artificially-infested microplots, root rot severity was low (<25%) and mean yield was not significantly reduced. However, there were significant linear relationships between yield and root symptoms for some isolates. Root morphological characteristics were more consistent indicators of yield loss than root rot severity. This study provides the first characterization of aggressiveness and yield impact of Fusarium root rot species on soybean at different plant stages and introduces root image analysis to assess the impact of root pathogens on soybean.

  6. Jasmonic acid and salicylic acid inhibit growth of three sugarbeet storage rot pathogens

    USDA-ARS?s Scientific Manuscript database

    Storage rots contribute to postharvest losses by consuming sucrose and increasing carbohydrate impurities that increase sugar loss to molasses during processing. They also increase root respiration rate, which causes additional sucrose loss and contributes to pile warming. Currently, storage rots ...

  7. Cassava C-repeat binding factor 1 gene responds to low temperature and enhances cold tolerance when overexpressed in Arabidopsis and cassava.

    PubMed

    An, Dong; Ma, Qiuxiang; Wang, Hongxia; Yang, Jun; Zhou, Wenzhi; Zhang, Peng

    2017-05-01

    Cassava MeCBF1 is a typical CBF transcription factor mediating cold responses but its low expression in apical buds along with a retarded response cause inefficient upregulation of downstream cold-related genes, rendering cassava chilling-sensitive. Low temperature is a major abiotic stress factor affecting survival, productivity and geographic distribution of important crops worldwide. The C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB) are important regulators of abiotic stress response in plants. In this study, MeCBF1, a CBF-like gene, was identified in the tropical root crop cassava (Manihot esculenta Crantz). The MeCBF1 encodes a protein that shares strong homology with DREB1As/CBFs from Arabidopsis as well as other species. The MeCBF1 was localized to the nucleus and is mainly expressed in stem and mature leaves, but not in apical buds or stem cambium. MeCBF1 expression was not only highly responsive to cold, but also significantly induced by salt, PEG and ABA treatment. Several stress-associated cis-elements were found in its promoter region, e.g., ABRE-related, MYC recognition sites, and MYB responsive element. Compared with AtCBF1, the MeCBF1 expression induced by cold in cassava was retarded and upregulated only after 4 h, which was also confirmed by its promoter activity. Overexpression of MeCBF1 in transgenic Arabidopsis and cassava plants conferred enhanced crytolerance. The CBF regulon was smaller and not entirely co-regulated with MeCBF1 expression in overexpressed cassava. The retarded MeCBF1 expression in response to cold and attenuated CBF-regulon might lead cassava to chilling sensitivity.

  8. Efficient transmission of cassava brown streak disease viral pathogens by chip bud grafting.

    PubMed

    Wagaba, Henry; Beyene, Getu; Trembley, Cynthia; Alicai, Titus; Fauquet, Claude M; Taylor, Nigel J

    2013-12-06

    Techniques to study plant viral diseases under controlled growth conditions are required to fully understand their biology and investigate host resistance. Cassava brown streak disease (CBSD) presents a major threat to cassava production in East Africa. No infectious clones of the causal viruses, Cassava brown streak virus (CBSV) or Ugandan cassava brown streak virus (UCBSV) are available, and mechanical transmission to cassava is not effective. An improved method for transmission of the viruses, both singly and as co-infections has been developed using bud grafts. Axillary buds from CBSD symptomatic plants infected with virulent isolates of CBSV and UCBSV were excised and grafted onto 6-8 week old greenhouse-grown, disease-free cassava plants of cultivars Ebwanateraka, TME204 and 60444. Plants were assessed visually for development of CBSD symptoms and by RT-PCR for presence of the viruses in leaf and storage root tissues. Across replicated experiments, 70-100% of plants inoculated with CBSV developed CBSD leaf and stem symptoms 2-6 weeks after bud grafting. Infected plants showed typical, severe necrotic lesions in storage roots at harvest 12-14 weeks after graft inoculation. Sequential grafting of buds from plants infected with UCBSV followed 10-14 days later by buds carrying CBSV, onto the same test plant, resulted in 100% of the rootstocks becoming co-infected with both pathogens. This dual transmission rate was greater than that achieved by simultaneous grafting with UCBSV and CBSV (67%), or when grafting first with CBSV followed by UCBSV (17%). The bud grafting method described presents an improved tool for screening cassava germplasm for resistance to CBSD causal viruses, and for studying pathogenicity of this important disease. Bud grafting provides new opportunities compared to previously reported top and side grafting systems. Test plants can be inoculated as young, uniform plants of a size easily handled in a small greenhouse or large growth chamber and

  9. Food safety: importance of composition for assessing genetically modified cassava (Manihot esculenta Crantz).

    PubMed

    van Rijssen, Fredrika W Jansen; Morris, E Jane; Eloff, Jacobus N

    2013-09-04

    The importance of food composition in safety assessments of genetically modified (GM) food is described for cassava ( Manihot esculenta Crantz) that naturally contains significantly high levels of cyanogenic glycoside (CG) toxicants in roots and leaves. The assessment of the safety of GM cassava would logically require comparison with a non-GM crop with a proven "history of safe use". This study investigates this statement for cassava. A non-GM comparator that qualifies would be a processed product with CG level below the approved maximum level in food and that also satisfies a "worst case" of total dietary consumption. Although acute and chronic toxicity benchmark CG values for humans have been determined, intake data are scarce. Therefore, the non-GM cassava comparator is defined on the "best available knowledge". We consider nutritional values for cassava and conclude that CG residues in food should be a priority topic for research.

  10. The Discrepant and Similar Responses of Genome-Wide Transcriptional Profiles between Drought and Cold Stresses in Cassava.

    PubMed

    Zeng, Changying; Ding, Zehong; Zhou, Fang; Zhou, Yufei; Yang, Ruiju; Yang, Zi; Wang, Wenquan; Peng, Ming

    2017-12-12

    Background : Cassava, an important tropical crop, has remarkable drought tolerance, but is very sensitive to cold. The growth, development, and root productivity of cassava are all adversely affected under cold and drought. Methods : To profile the transcriptional response to cold and drought stresses, cassava seedlings were respectively subjected to 0, 6, 24, and 48 h of cold stress and 0, 4, 6, and 10 days of drought stress. Their folded leaves, fully extended leaves, and roots were respectively investigated using RNA-seq. Results : Many genes specifically and commonly responsive to cold and drought were revealed: genes related to basic cellular metabolism, tetrapyrrole synthesis, and brassinosteroid metabolism exclusively responded to cold; genes related to abiotic stress and ethylene metabolism exclusively responded to drought; and genes related to cell wall, photosynthesis, and carbohydrate metabolism, DNA synthesis/chromatic structure, abscisic acid and salicylic acid metabolism, and calcium signaling commonly responded to both cold and drought. Discussion : Combined with cold- and/or drought-responsive transcription factors, the regulatory networks responding to cold and drought in cassava were constructed. All these findings will improve our understanding of the specific and common responses to cold and drought in cassava, and shed light on genetic improvement of cold and drought tolerance in cassava.

  11. Phylogenetic and population analyses of the invasive brown root-rot pathogen (Phellinus noxius) highlight the existence of at least two distinct populations

    Treesearch

    J. E. Stewart; N. Sahashi; T. Hattori; M. Akiba; Y. Ota; L. Shuey; R. L. Schlub; N. Atibalentia; F. Brooks; A. M. C. Tang; R. Y. C. Lam; M. W. K. Leung; L. M. Chu; H. S. Kwan; A. Mohd Farid; S. S. Lee; C. -L. Chung; H. -H. Lee; Y.- C. Huang; R. -F. Liou; J. -N. Tsai; P. G. Cannon; J. W. Hanna; N. B. Klopfenstein; M. -S. Kim

    2017-01-01

    Phellinus noxius (Corner) G. H. Cunn is a vastly destructive, fast-growing pathogen that affects a wide range of woody hosts in pan-tropical areas, including Asia, Australia, Africa, and Oceania (Ann et al. 2002). This invasive pathogen causes brown root-rot disease on cacao, coffee, and rubber, as well as diverse fruit, nut, ornamental, and other native/exotic trees,...

  12. Transgenic Biofortification of the Starchy Staple Cassava (Manihot esculenta) Generates a Novel Sink for Protein

    PubMed Central

    Abhary, Mohammad; Siritunga, Dimuth; Stevens, Gene; Taylor, Nigel J.; Fauquet, Claude M.

    2011-01-01

    Although calorie dense, the starchy, tuberous roots of cassava provide the lowest sources of dietary protein within the major staple food crops (Manihot esculenta Crantz). (Montagnac JA, Davis CR, Tanumihardjo SA. (2009) Compr Rev Food Sci Food Saf 8:181–194). Cassava was genetically modified to express zeolin, a nutritionally balanced storage protein under control of the patatin promoter. Transgenic plants accumulated zeolin within de novo protein bodies localized within the root storage tissues, resulting in total protein levels of 12.5% dry weight within this tissue, a fourfold increase compared to non-transgenic controls. No significant differences were seen for morphological or agronomic characteristics of transgenic and wild type plants in the greenhouse and field trials, but relative to controls, levels of cyanogenic compounds were reduced by up to 55% in both leaf and root tissues of transgenic plants. Data described here represent a proof of concept towards the potential transformation of cassava from a starchy staple, devoid of storage protein, to one capable of supplying inexpensive, plant-based proteins for food, feed and industrial applications. PMID:21283593

  13. Transgenic biofortification of the starchy staple cassava (Manihot esculenta) generates a novel sink for protein.

    PubMed

    Abhary, Mohammad; Siritunga, Dimuth; Stevens, Gene; Taylor, Nigel J; Fauquet, Claude M

    2011-01-25

    Although calorie dense, the starchy, tuberous roots of cassava provide the lowest sources of dietary protein within the major staple food crops (Manihot esculenta Crantz). (Montagnac JA, Davis CR, Tanumihardjo SA. (2009) Compr Rev Food Sci Food Saf 8:181-194). Cassava was genetically modified to express zeolin, a nutritionally balanced storage protein under control of the patatin promoter. Transgenic plants accumulated zeolin within de novo protein bodies localized within the root storage tissues, resulting in total protein levels of 12.5% dry weight within this tissue, a fourfold increase compared to non-transgenic controls. No significant differences were seen for morphological or agronomic characteristics of transgenic and wild type plants in the greenhouse and field trials, but relative to controls, levels of cyanogenic compounds were reduced by up to 55% in both leaf and root tissues of transgenic plants. Data described here represent a proof of concept towards the potential transformation of cassava from a starchy staple, devoid of storage protein, to one capable of supplying inexpensive, plant-based proteins for food, feed and industrial applications.

  14. Impact of genotype and cooking style on the content, retention, and bioacessibility of β-carotene in biofortified cassava (Manihot esculenta Crantz) conventionally bred in Brazil.

    PubMed

    Berni, Paulo; Chitchumroonchokchai, Chureeporn; Canniatti-Brazaca, Solange G; De Moura, Fabiana F; Failla, Mark L

    2014-07-16

    Biofortification is a strategy for decreasing micronutrient deficiencies in vulnerable populations by increasing nutrient density in staple food crops. Roots from five varieties of cassava biofortified with β-carotene (βC), three parental accessions, and one variety of commonly consumed white cassava from Brazil were investigated. Roots from biofortified varieties contained up to 23-fold higher βC than white cassava, and the additional complement of βC was primarily the all-trans isomer. At least 68% of βC per gram fresh weight was retained after boiling or boiling and briefly frying. Micellarization of βC during simulated digestion of fried root exceeded that of boiled root. Apical uptake of all-trans-βC from mixed micelles by Caco-2 cells was affected by an interaction between variety and cooking style. These results suggest that Brazilian cassava biofortified with βC has the potential to reduce vitamin A deficiency without requiring major changes in local and ethnic styles of home cooking.

  15. Development and application of qPCR and RPA genus and species-specific detection of Phytophthora sojae and Phytophthora sansomeana root rot pathogens of soybean

    USDA-ARS?s Scientific Manuscript database

    Phytophthora root rot of soybean, caused by Phytophthora sojae is one of the most important diseases in the Midwest US, causing losses of up to 44 million bushels per year. Disease may also be caused by P. sansomeana, however the prevalence and damage caused by this species is not well known, partl...

  16. Potassium fertilizer applied immediately after planting had no impact on Douglas-fir seedling mortality caused by laminated root rot on a forested site in Washington State.

    Treesearch

    Walter G. Thies; Rick G. Kelsey; Douglas J. Westlind; Jeff Madsen

    2006-01-01

    Phellinus weirii causes laminated root rot (LRR), a major disease affecting growth and survival of Pseudotsuga menziesii (Douglas-fir) and other commercially important conifer species throughout the Pacific Northwest. Increasing tree vigor and resistance to pathogens through application of K fertilizer is a suggested disease...

  17. Allele exchange at the EPSPS locus confers glyphosate tolerance in cassava.

    PubMed

    Hummel, Aaron W; Chauhan, Raj Deepika; Cermak, Tomas; Mutka, Andrew M; Vijayaraghavan, Anupama; Boyher, Adam; Starker, Colby G; Bart, Rebecca; Voytas, Daniel F; Taylor, Nigel J

    2017-12-09

    Effective weed control can protect yields of cassava (Manihot esculenta) storage roots. Farmers could benefit from using herbicide with a tolerant cultivar. We applied traditional transgenesis and gene editing to generate robust glyphosate tolerance in cassava. By comparing promoters regulating expression of transformed 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) genes with various paired amino acid substitutions, we found that strong constitutive expression is required to achieve glyphosate tolerance during in vitro selection and in whole cassava plants. Using strategies that exploit homologous recombination (HR) and nonhomologous end-joining (NHEJ) DNA repair pathways, we precisely introduced the best-performing allele into the cassava genome, simultaneously creating a promoter swap and dual amino acid substitutions at the endogenous EPSPS locus. Primary EPSPS-edited plants were phenotypically normal, tolerant to high doses of glyphosate, with some free of detectable T-DNA integrations. Our methods demonstrate an editing strategy for creating glyphosate tolerance in crop plants and demonstrate the potential of gene editing for further improvement of cassava. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  18. Diallel analysis of provitamin A carotenoid and dry matter content in cassava (Manihot esculenta Crantz)

    PubMed Central

    Esuma, Williams; Kawuki, Robert S.; Herselman, Liezel; Labuschagne, Maryke Tine

    2016-01-01

    Global efforts are underway to biofortify cassava (Manihot esculenta Crantz) with provitamin A carotenoids to help combat dietary vitamin A deficiency afflicting the health of more than 500 million resource-poor people in Sub-Saharan Africa. To further the biofortification initiative in Uganda, a 6×6 diallel analysis was conducted to estimate combining ability of six provitamin A clones and gene actions controlling total carotenoid content (TCC), dry matter content (DMC) in cassava roots and other relevant traits. Fifteen F1 families generated from the diallel crosses were evaluated in two environments using a randomized complete block design. General combining ability (GCA) effects were significant for TCC and DMC, suggesting the relative importance of additive gene effects in controlling these traits in cassava. On the other hand, non-additive effects were predominant for root and shoot weight. MH02-073HS, with the highest level of TCC, was the best general combiner for TCC while NASE 3, a popular white-fleshed variety grown by farmers in Uganda, was the best general combiner for DMC. Such progenitors with superior GCA effects could form the genetic source for future programs targeting cassava breeding for TCC and DMC. A negative correlation was observed between TCC and DMC, which will require breeding strategies to combine both traits for increased adoption of provitamin A cassava varieties. PMID:27795688

  19. Whitefly Bemisia tabaci (Homoptera: Aleyrodidae) infestation on cassava genotypes grown at different ecozones in Nigeria.

    PubMed

    Ariyo, O A; Dixon, A G O; Atiri, G I

    2005-04-01

    Large-scale screening of cassava, Manihot esculenta Crantz, genotypes for resistance to infestation by whitefly Bemisia tabaci Gennadius, the vector of cassava mosaic geminiviruses, is limited. A range of new cassava elite clones were therefore assessed for the whitefly infestation in the 1999/2000 and 2000/2001 cropping seasons in experimental fields of International Institute of Tropical Agriculture, Ibadan, Nigeria. On each scoring day, between 0600 and 0800 hours when the whiteflies were relatively immobile, adult whitefly populations on the five topmost expanded leaves of cassava cultivars were counted. All through the 6-mo scoring period, there was a highly significant difference in whitefly infestation among the new cassava elite clones. Vector population buildup was observed in Ibadan (forest-savanna transition zone) and Onne (humid forest), 2 mo after planting (MAP). Mean infestation across cassava genotypes was significantly highest (16.6 whiteflies per plant) in Ibadan and lowest in Zaria (0.2). Generally, whitefly infestation was very low in all locations at 5 and 6 MAP. During this period, cassava genotypes 96/1439 and 91/02324 significantly supported higher infestations than other genotypes. Plants of 96/1089A and TMS 30572 supported the lowest whitefly infestation across cassava genotypes in all locations. The preferential whitefly visitation, the differences between locations in relation to whitefly population, cassava mosaic disease, and the fresh root yield of cassava genotypes are discussed.

  20. The role of defoliation and root rot pathogen infection in driving the mode of drought-related physiological decline in Scots pine (Pinus sylvestris L.).

    PubMed

    Aguadé, D; Poyatos, R; Gómez, M; Oliva, J; Martínez-Vilalta, J

    2015-03-01

    Drought-related tree die-off episodes have been observed in all vegetated continents. Despite much research effort, however, the multiple interactions between carbon starvation, hydraulic failure and biotic agents in driving tree mortality under field conditions are still not well understood. We analysed the seasonal variability of non-structural carbohydrates (NSCs) in four organs (leaves, branches, trunk and roots), the vulnerability to embolism in roots and branches, native embolism (percentage loss of hydraulic conductivity (PLC)) in branches and the presence of root rot pathogens in defoliated and non-defoliated individuals in a declining Scots pine (Pinus sylvestris L.) population in the NE Iberian Peninsula in 2012, which included a particularly dry and warm summer. No differences were observed between defoliated and non-defoliated pines in hydraulic parameters, except for a higher vulnerability to embolism at pressures below -2 MPa in roots of defoliated pines. No differences were found between defoliation classes in branch PLC. Total NSC (TNSC, soluble sugars plus starch) values decreased during drought, particularly in leaves. Defoliation reduced TNSC levels across tree organs, especially just before (June) and during (August) drought. Root rot infection by the fungal pathogen Onnia P. Karst spp. was detected but it did not appear to be associated to tree defoliation. However, Onnia infection was associated with reduced leaf-specific hydraulic conductivity and sapwood depth, and thus contributed to hydraulic impairment, especially in defoliated pines. Infection was also associated with virtually depleted root starch reserves during and after drought in defoliated pines. Moreover, defoliated and infected trees tended to show lower basal area increment. Overall, our results show the intertwined nature of physiological mechanisms leading to drought-induced mortality and the inherent difficulty of isolating their contribution under field conditions. © The

  1. Occupational exposure to hydrogen cyanide during large-scale cassava processing, in Alagoas State, Brazil.

    PubMed

    Zacarias, Cyro Hauaji; Esteban, Claudia; Rodrigues, Gilson Lucio; Nascimento, Elizabeth de Souza

    2017-07-27

    The cassava roots used for flour production contain high amounts of cyanogenic glycosides and are, therefore, potential hydrogen cyanide (HCN) releasers. This fact is the cause of an increasing health concern in the sector of cassava processing. Brazilian workers engaged in the flour production may be chronically exposed to HCN in levels above the safety limits. This hypothesis is based on the drastic reduction in cyanide content of cassava roots during a traditional Brazilian method of processing and in the physical properties of the compound, which makes it very susceptible to volatilization and air contamination. As an attempt to explore this issue, HCN exposure in Brazilian "flour houses" was evaluated in this study through environmental and biological monitoring. Four flour houses placed in Alagoas State, Brazil, were investigated. The results indicated that the cassava processors are chronically exposed to HCN at average levels between 0.464 and 3.328mg/m3 (TWA), in the work environment. This range is below the TLV-C of 5mg/m3 but not below the Action Level of 2.5mg/m3. These data may be interpreted as a possible risk to susceptible individuals. Additionally, the biological monitoring indicated a high cyanide exposure in the population study, considering urinary thiocyanate (SCN-) levels.

  2. Electrical and absorption properties of fresh cassava tubers and cassava starch

    NASA Astrophysics Data System (ADS)

    Harnsoongnoen, S.; Siritaratiwat, A.

    2015-09-01

    The objective of this study was to analyze the electrical and absorption properties of fresh cassava tubers and cassava starch at various frequencies using electric impedance spectroscopy and near-infrared spectroscopy, as well as determine the classification of the electrical parameters of both materials using the principle component analysis (PCA) method. All samples were measured at room temperature. The electrical and absorption parameters consisted of dielectric constant, dissipation factor, parallel capacitance, resistance, reactance, impedance and absorbance. It was found that the electrical and absorption properties of fresh cassava tubers and cassava starch were a function of frequency, and there were significant differences between the materials. The dielectric constant, parallel capacitance, resistance and impedance of fresh cassava tubers and cassava starch had similar dramatic decreases with increasing frequency. However, the reactance of both materials increased with an increasing frequency. The electrical parameters of both materials could be classified into two groups. Moreover, the dissipation factor and phase of impedance were the parameters that could be used in the separation of both materials. According to the absorbance patterns of the fresh cassava tubers and cassava starch, there were significant differences.

  3. Fusarium culmorum: causal agent of foot and root rot and head blight on wheat.

    PubMed

    Scherm, Barbara; Balmas, Virgilio; Spanu, Francesca; Pani, Giovanna; Delogu, Giovanna; Pasquali, Matias; Migheli, Quirico

    2013-05-01

    Fusarium culmorum is a ubiquitous soil-borne fungus able to cause foot and root rot and Fusarium head blight on different small-grain cereals, in particular wheat and barley. It causes significant yield and quality losses and results in contamination of the grain with mycotoxins. This review summarizes recent research activities related to F. culmorum, including studies into its population diversity, mycotoxin biosynthesis, mechanisms of pathogenesis and resistance, the development of diagnostic tools and preliminary genome sequence surveys. We also propose potential research areas that may expand our basic understanding of the wheat-F. culmorum interaction and assist in the management of the disease caused by this pathogen. Fusarium culmorum (W.G. Smith) Sacc. Kingdom Fungi; Phylum Ascomycota; Subphylum Pezizomycotina; Class Sordariomycetes; Subclass Hypocreomycetidae; Order Hypocreales; Family Nectriaceae; Genus Fusarium. Foot and root rot (also known as Fusarium crown rot): seedling blight with death of the plant before or after emergence; brown discoloration on roots and coleoptiles of the infected seedlings; brown discoloration on subcrown internodes and on the first two/three internodes of the main stem; tiller abortion; formation of whiteheads with shrivelled white grains; Fusarium head blight: prematurely bleached spikelets or blighting of the entire head, which remains empty or contains shrunken dark kernels. IDENTIFICATION AND DETECTION: Morphological identification is based on the shape of the macroconidia formed on sporodochia on carnation leaf agar. The conidiophores are branched monophialides, short and wide. The macroconidia are relatively short and stout with an apical cell blunt or slightly papillate; the basal cell is foot-shaped or just notched. Macroconidia are thick-walled and curved, usually 3-5 septate, and mostly measuring 30-50 × 5.0-7.5 μm. Microconidia are absent. Oval to globose chlamydospores are formed, intercalary in the

  4. Sensorial evolution of cassava flour (Manihot esculenta crantz) added to protein concentrate cassava leaves

    PubMed Central

    Lima, Elaine C S; Feijo, Márcia B S; Freitas, Maria C J; dos Santos, Edna R; Sabaa-Srur, Armando U O; Moura, Luciana S M

    2013-01-01

    Cassava is regarded as the nutritional base of populations in developing countries, and flour, product made of cassava, is the most consumed in the world. The cassava leaves are very rich in vegetable proteins, but a big amount is lost in processing the crop. The objective of this study was to do a sensory evaluation of cassava flour to which a protein concentrate obtained from cassava leaves (CPML) was added. The CPML was obtained from cassava leaves by isoelectric precipitation and added to cassava paste for preparation of flour in three parts 2.5, 5, and 10%. The acceptance test was done by 93 consumers of flour, using hedonic scale of 7 points to evaluate characteristics like color, scent, flavor, bitterness, texture, and overall score. By the method of quantitative descriptive analysis (QDA), eight trained tasters evaluated the following characteristics: whitish color, greenish color, cassava flavor, bitter flavor, characteristic flavor, lumpiness, raw texture, leaf scent, and cassava scent. The acceptability test indicated that flour cassava with 2.5 was preferred. Whitish color, greenish color, cassava flavor, bitter flavor, salty flavor, characteristic flavor, lumpiness texture, raw texture, and the smell of the leaves and cassava flour were the main descriptors defined for flour cassava with CPML has better characteristics. PMID:24804041

  5. Mechanism of cassava tuber cell wall weakening by dilute sodium hydroxide steeping.

    PubMed

    Odoch, Martin; Buys, Elna M; Taylor, John R N

    2017-08-01

    Steeping of cassava root pieces in 0.75% NaOH in combination with wet milling was investigated to determine whether and how dilute NaOH modifies cassava cell walls. Gas chromatography data of cell wall constituent sugar composition and Fourier transform infrared (FTIR) data showed that NaOH steeping reduced the level of pectin in cassava cell walls. FTIR and wide-angle X-ray scattering spectroscopy also indicated that NaOH steeping combined with fine milling slightly reduced cellulose crystallinity. Scanning electron microscopy showed that NaOH steeping produced micropores in the cell walls and light microscopy revealed that NaOH steeping increased disaggregation of parenchyma cells. Steeping of ground cassava in NaOH resulted in a 12% decrease in large residue particles and approx. 4% greater starch yield with wet milling. Therefore dilute NaOH steeping can improve the effectiveness of wet milling in disintegrating cell walls through solubilisation of pectin, thereby reduced cell wall strength. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Biorefinery integration of microalgae production into cassava processing industry: Potential and perspectives.

    PubMed

    de Carvalho, Júlio Cesar; Borghetti, Ivo Alberto; Cartas, Liliana Carrilo; Woiciechowski, Adenise Lorenci; Soccol, Vanete Thomaz; Soccol, Carlos Ricardo

    2018-01-01

    Cassava, the 5th most important staple crop, generates at least 600L of wastewater per ton of processed root. This residue, cassava processing wastewater (CPW) has a high chemical oxygen demand, that can reach 56 g/L, and has also high concentrations of several mineral nutrients. The cultivation of microalgae such as Chlorella, Spirulina and wild strains was evaluated in the last years in raw, minimally processed and partially digested CPW. Concentrations of 2-4 g/L of these microalgae, comparable to those obtained in synthetic media, could be reached. The BOD of the residue was reduced by up to 92%. This process can be integrated into cassava processing industries, if challenges such as the toxicity of the concentrated residue, bacterial contamination, and the isolation of robust strains are addressed. Because CPW carries about 11% of the crop energy, integrating biogas production and microalgal cultivation into the cassava processing chain is promising. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Computational identification of microRNAs and their targets in cassava (Manihot esculenta Crantz.).

    PubMed

    Patanun, Onsaya; Lertpanyasampatha, Manassawe; Sojikul, Punchapat; Viboonjun, Unchera; Narangajavana, Jarunya

    2013-03-01

    MicroRNAs (miRNAs) are a newly discovered class of noncoding endogenous small RNAs involved in plant growth and development as well as response to environmental stresses. miRNAs have been extensively studied in various plant species, however, only few information are available in cassava, which serves as one of the staple food crops, a biofuel crop, animal feed and industrial raw materials. In this study, the 169 potential cassava miRNAs belonging to 34 miRNA families were identified by computational approach. Interestingly, mes-miR319b was represented as the first putative mirtron demonstrated in cassava. A total of 15 miRNA clusters involving 7 miRNA families, and 12 pairs of sense and antisense strand cassava miRNAs belonging to six different miRNA families were discovered. Prediction of potential miRNA target genes revealed their functions involved in various important plant biological processes. The cis-regulatory elements relevant to drought stress and plant hormone response were identified in the promoter regions of those miRNA genes. The results provided a foundation for further investigation of the functional role of known transcription factors in the regulation of cassava miRNAs. The better understandings of the complexity of miRNA-mediated genes network in cassava would unravel cassava complex biology in storage root development and in coping with environmental stresses, thus providing more insights for future exploitation in cassava improvement.

  8. Ethylene Responsive Factor MeERF72 Negatively Regulates Sucrose synthase 1 Gene in Cassava.

    PubMed

    Liu, Chen; Chen, Xin; Ma, Ping'an; Zhang, Shengkui; Zeng, Changying; Jiang, Xingyu; Wang, Wenquan

    2018-04-25

    Cassava, an important food and industrial crop globally, is characterized by its powerful starch accumulation in its storage root. However, the underlying molecular mechanism for this feature remains unclear. Sucrose synthase initializes the conversion of sucrose to starch, and, to a certain extent, its enzyme activity can represent sink strength. To understand the modulation of MeSus gene family, the relatively high expressed member in storage root, MeSus1 , its promoter was used as bait to screen cassava storage root full-length cDNA library through a yeast one-hybrid system. An ethylene responsive factor cDNA, designated as MeERF72 according to its homolog in Arabidopsis , was screened out. The transcript level of MeERF72 was induced by ethylene, drought, and salt treatments and repressed by abscisic acid, Auxin, gibberellin, salicylic acid, and low and high temperatures. The MeERF72 protein has a conserved APETALA2 domain in its N-terminus and an activated domain of 30 amino acids in its C-terminus, can bind to MeSus1 promoter in vitro and in vivo, and represses the promoter activity of MeSus1 . MeERF72 is a transcription factor that can negatively regulate the expression level of MeSus1 in cassava.

  9. Effect of Environment and Sugar Beet Genotype on Root Rot Development and Pathogen Profile During Storage.

    PubMed

    Liebe, Sebastian; Varrelmann, Mark

    2016-01-01

    Storage rots represent an economically important factor impairing the storability of sugar beet by increasing sucrose losses and invert sugar content. Understanding the development of disease management strategies, knowledge about major storage pathogens, and factors influencing their occurrence is crucial. In comprehensive storage trials conducted under controlled conditions, the effects of environment and genotype on rot development and associated quality changes were investigated. Prevalent species involved in rot development were identified by a newly developed microarray. The strongest effect on rot development was assigned to environment factors followed by genotypic effects. Despite large variation in rot severity (sample range 0 to 84%), the spectrum of microorganisms colonizing sugar beet remained fairly constant across all treatments with dominant species belonging to the fungal genera Botrytis, Fusarium, and Penicillium. The intensity of microbial tissue necrotization was strongly correlated with sucrose losses (R² = 0.79 to 0.91) and invert sugar accumulation (R² = 0.91 to 0.95). A storage rot resistance bioassay was developed that could successfully reproduce the genotype ranking observed in storage trials. Quantification of fungal biomass indicates that genetic resistance is based on a quantitative mechanism. Further work is required to understand the large environmental influence on rot development in sugar beet.

  10. Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber.

    PubMed

    Bradley, Geoffrey G; Punja, Zamir K

    2010-11-01

    Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola, plus 2 biocontrol strains of Pseudomonas fluorescens, were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 10(6) ± 0.73 × 10(6) CFU·(g root tissue)-1 and survival was >107 CFU·(g compost)-1 after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

  11. A Comparative Study of Some Properties of Cassava and Tree Cassava Starch Films

    NASA Astrophysics Data System (ADS)

    Belibi, P. C.; Daou, T. J.; Ndjaka, J. M. B.; Nsom, B.; Michelin, L.; Durand, B.

    Cassava and tree cassava starch films plasticized with glycerol were produced by casting method. Different glycerol contents (30, 35, 40 and 45 wt. % on starch dry basis) were used and the resulting films were fully characterized. Their water barrier and mechanical properties were compared. While increasing glycerol concentration, moisture content, water solubility, water vapour permeability, tensile strength, percent elongation at break and Young's modulus decreased for both cassava and tree cassava films. Tree cassava films presented better values of water vapour permeability, water solubility and percent elongation at break compared to those of cassava films, regardless of the glycerol content.

  12. Genome-Wide Identification and Expression Analysis of the KUP Family under Abiotic Stress in Cassava (Manihot esculenta Crantz).

    PubMed

    Ou, Wenjun; Mao, Xiang; Huang, Chao; Tie, Weiwei; Yan, Yan; Ding, Zehong; Wu, Chunlai; Xia, Zhiqiang; Wang, Wenquan; Zhou, Shiyi; Li, Kaimian; Hu, Wei

    2018-01-01

    KT/HAK/KUP (KUP) family is responsible for potassium ion (K + ) transport, which plays a vital role in the response of plants to abiotic stress by maintaining osmotic balance. However, our understanding of the functions of the KUP family in the drought-resistant crop cassava ( Manihot esculenta Crantz) is limited. In the present study, 21 cassava KUP genes ( MeKUPs ) were identified and classified into four clusters based on phylogenetic relationships, conserved motifs, and gene structure analyses. Transcriptome analysis revealed the expression diversity of cassava KUPs in various tissues of three genotypes. Comparative transcriptome analysis showed that the activation of MeKUP genes by drought was more in roots than that in leaves of Arg7 and W14 genotypes, whereas less in roots than that in leaves of SC124 variety. These findings indicate that different cassava genotypes utilize various drought resistance mechanism mediated by KUP genes. Specific KUP genes showed broad upregulation after exposure to salt, osmotic, cold, H 2 O 2 , and abscisic acid (ABA) treatments. Taken together, this study provides insights into the KUP -mediated drought response of cassava at transcription levels and identifies candidate genes that may be utilized in improving crop tolerance to abiotic stress.

  13. Contribution of selected fungi to the reduction of cyanogen levels during solid substrate fermentation of cassava.

    PubMed

    Essers, A J; Jurgens, C M; Nout, M J

    1995-07-01

    The effect of six individual strains of the dominant microflora in solid substrate fermenting cassava on cyanogen levels was examined. Six out of eight batches of disinfected cassava root pieces were incubated for 72 h after inoculation with either of the fungi Geotrichum candidum, Mucor racemosus, Neurospora sitophila, Rhizopus oryzae and Rhizopus stolonifer, or a Bacillus sp., isolated from on-farm fermented cassava flours from Uganda. One non-inoculated batch was incubated as a reference. Levels of initial and final moisture and cyanogens were assayed. The experiment was done in quadruplicate. Incubation of disinfected root pieces reduced cyanogenic glucoside levels significantly to 62.7% (SD 2.8) of the initial value. Microbial growth resulted in significant additional reduction of the cyanogenic glucoside levels to 29.8% (SD 18.9) of the levels which were obtained after non-inoculated incubation. Among the tested strains, N. sitophila reduced cyanogenic glucoside levels most effectively, followed by R. stolonifer and R. oryzae. Of all fermented samples, both Rhizopus spp. showed highest proportion of residual cyanogens in the cyanohydrin form. Flours showed similar patterns of cyanogens as the batches they were prepared from. Cyanogenic glucoside level reduction was significantly correlated (r = 0.86) with the extent of root softening. It is concluded that both incubation and microbial activity are instrumental in reducing the potential toxicity of cassava during the solid substrate fermentation and that effectiveness varies considerably between the species of microorganisms applied.

  14. The teratogenic effects of dietary Cassava on the pregnant albino rat: a preliminary report.

    PubMed

    Singh, J D

    1981-12-01

    Cassava is a tuberous root of a shrublike plant cultivated in tropical rain forests as a staple food in South Eastern Nigeria. Reports are on record showing correlation between cassava intake and occurrence of various types of neuropathies (Money, '59; Monekosso and Wilson, '66; Osuntokun et al., '68,'69). About 0.1-2 mg of cyanide/100 gm is released from Cassava by action of hydrolase (Paula and Rangel, '46). It has been suspected by several local clinicians as a cause of congenital anomalies if consumed in excess during pregnancy. However, it remains a controversial problem and precise scientific data is lacking. This study was conducted on albino rats by giving them milled cassava powder as 50% and 80% of their diet during the first 5 days of pregnancy. Fetuses collected on day 20 from the group receiving cassava as 80% of the diet showed a low incidence of limb defects, open eye, microcephaly, and growth retardation in the rat. Interpretation of this data for the human should be made with caution.

  15. Identification, validation and high-throughput genotyping of transcribed gene SNPs in cassava.

    PubMed

    Ferguson, Morag E; Hearne, Sarah J; Close, Timothy J; Wanamaker, Steve; Moskal, William A; Town, Christopher D; de Young, Joe; Marri, Pradeep Reddy; Rabbi, Ismail Yusuf; de Villiers, Etienne P

    2012-03-01

    The availability of genomic resources can facilitate progress in plant breeding through the application of advanced molecular technologies for crop improvement. This is particularly important in the case of less researched crops such as cassava, a staple and food security crop for more than 800 million people. Here, expressed sequence tags (ESTs) were generated from five drought stressed and well-watered cassava varieties. Two cDNA libraries were developed: one from root tissue (CASR), the other from leaf, stem and stem meristem tissue (CASL). Sequencing generated 706 contigs and 3,430 singletons. These sequences were combined with those from two other EST sequencing initiatives and filtered based on the sequence quality. Quality sequences were aligned using CAP3 and embedded in a Windows browser called HarvEST:Cassava which is made available. HarvEST:Cassava consists of a Unigene set of 22,903 quality sequences. A total of 2,954 putative SNPs were identified. Of these 1,536 SNPs from 1,170 contigs and 53 cassava genotypes were selected for SNP validation using Illumina's GoldenGate assay. As a result 1,190 SNPs were validated technically and biologically. The location of validated SNPs on scaffolds of the cassava genome sequence (v.4.1) is provided. A diversity assessment of 53 cassava varieties reveals some sub-structure based on the geographical origin, greater diversity in the Americas as opposed to Africa, and similar levels of diversity in West Africa and southern, eastern and central Africa. The resources presented allow for improved genetic dissection of economically important traits and the application of modern genomics-based approaches to cassava breeding and conservation.

  16. Genome-Wide Association Mapping of Correlated Traits in Cassava: Dry Matter and Total Carotenoid Content.

    PubMed

    Rabbi, Ismail Y; Udoh, Lovina I; Wolfe, Marnin; Parkes, Elizabeth Y; Gedil, Melaku A; Dixon, Alfred; Ramu, Punna; Jannink, Jean-Luc; Kulakow, Peter

    2017-11-01

    Cassava is a starchy root crop cultivated in the tropics for fresh consumption and commercial processing. Primary selection objectives in cassava breeding include dry matter content and micronutrient density, particularly provitamin A carotenoids. These traits are negatively correlated in the African germplasm. This study aimed at identifying genetic markers associated with these traits and uncovering whether linkage and/or pleiotropy were responsible for observed negative correlation. A genome-wide association mapping using 672 clones genotyped at 72,279 single nucleotide polymorphism (SNP) loci was performed. Root yellowness was used indirectly to assess variation in carotenoid content. Two major loci for root yellowness were identified on chromosome 1 at positions 24.1 and 30.5 Mbp. A single locus for dry matter content that colocated with the 24.1 Mbp peak for carotenoids was identified. Haplotypes at these loci explained 70 and 37% of the phenotypic variability for root yellowness and dry matter content, respectively. Evidence of megabase-scale linkage disequilibrium (LD) around the major loci of the two traits and detection of the major dry matter locus in independent analysis for the white- and yellow-root subpopulations suggests that physical linkage rather that pleiotropy is more likely to be the cause of the negative correlation between the target traits. Moreover, candidate genes for carotenoid () and starch biosynthesis ( and ) occurred in the vicinity of the identified locus at 24.1 Mbp. These findings elucidate the genetic architecture of carotenoids and dry matter in cassava and provide an opportunity to accelerate breeding of these traits. Copyright © 2017 Crop Science Society of America.

  17. Isolation and Characterization of Ftsz Genes in Cassava.

    PubMed

    Geng, Meng-Ting; Min, Yi; Yao, Yuan; Chen, Xia; Fan, Jie; Yuan, Shuai; Wang, Lei; Sun, Chong; Zhang, Fan; Shang, Lu; Wang, Yun-Lin; Li, Rui-Mei; Fu, Shao-Ping; Duan, Rui-Jun; Liu, Jiao; Hu, Xin-Wen; Guo, Jian-Chun

    2017-12-15

    The filamenting temperature-sensitive Z proteins (FtsZs) play an important role in plastid division. In this study, three FtsZ genes were isolated from the cassava genome, and named MeFtsZ1, MeFtsZ2-1, and MeFtsZ2-2, respectively. Based on phylogeny, the MeFtsZs were classified into two groups (FtsZ1 and FtsZ2). MeFtsZ1 with a putative signal peptide at N-terminal, has six exons, and is classed to FtsZ1 clade. MeFtsZ2-1 and MeFtsZ2-2 without a putative signal peptide, have seven exons, and are classed to FtsZ2 clade. Subcellular localization found that all the three MeFtsZs could locate in chloroplasts and form a ring in chloroplastids. Structure analysis found that all MeFtsZ proteins contain a conserved guanosine triphosphatase (GTPase) domain in favor of generate contractile force for cassava plastid division. The expression profiles of MeFtsZ genes by quantitative reverse transcription-PCR (qRT-PCR) analysis in photosynthetic and non-photosynthetic tissues found that all of the MeFtsZ genes had higher expression levels in photosynthetic tissues, especially in younger leaves, and lower expression levels in the non-photosynthetic tissues. During cassava storage root development, the expressions of MeFtsZ2-1 and MeFtsZ2-2 were comparatively higher than MeFtsZ1. The transformed Arabidopsis of MeFtsZ2-1 and MeFtsZ2-2 contained abnormally shape, fewer number, and larger volume chloroplasts. Phytohormones were involved in regulating the expressions of MeFtsZ genes. Therefore, we deduced that all of the MeFtsZs play an important role in chloroplast division, and that MeFtsZ 2 (2-1, 2-2) might be involved in amyloplast division and regulated by phytohormones during cassava storage root development.

  18. Genome-Wide Association Studies of 11 Agronomic Traits in Cassava (Manihot esculenta Crantz)

    PubMed Central

    Zhang, Shengkui; Chen, Xin; Lu, Cheng; Ye, Jianqiu; Zou, Meiling; Lu, Kundian; Feng, Subin; Pei, Jinli; Liu, Chen; Zhou, Xincheng; Ma, Ping’an; Li, Zhaogui; Liu, Cuijuan; Liao, Qi; Xia, Zhiqiang; Wang, Wenquan

    2018-01-01

    Cassava (Manihot esculenta Crantz) is a major tuberous crop produced worldwide. In this study, we sequenced 158 diverse cassava varieties and identified 349,827 single-nucleotide polymorphisms (SNPs) and indels. In each chromosome, the number of SNPs and the physical length of the respective chromosome were in agreement. Population structure analysis indicated that this panel can be divided into three subgroups. Genetic diversity analysis indicated that the average nucleotide diversity of the panel was 1.21 × 10-4 for all sampled landraces. This average nucleotide diversity was 1.97 × 10-4, 1.01 × 10-4, and 1.89 × 10-4 for subgroups 1, 2, and 3, respectively. Genome-wide linkage disequilibrium (LD) analysis demonstrated that the average LD was about ∼8 kb. We evaluated 158 cassava varieties under 11 different environments. Finally, we identified 36 loci that were related to 11 agronomic traits by genome-wide association analyses. Four loci were associated with two traits, and 62 candidate genes were identified in the peak SNP sites. We found that 40 of these genes showed different expression profiles in different tissues. Of the candidate genes related to storage roots, Manes.13G023300, Manes.16G000800, Manes.02G154700, Manes.02G192500, and Manes.09G099100 had higher expression levels in storage roots than in leaf and stem; on the other hand, of the candidate genes related to leaves, Manes.05G164500, Manes.05G164600, Manes.04G057300, Manes.01G202000, and Manes.03G186500 had higher expression levels in leaves than in storage roots and stem. This study provides basis for research on genetics and the genetic improvement of cassava. PMID:29725343

  19. Genome-Wide Association Studies of 11 Agronomic Traits in Cassava (Manihot esculenta Crantz).

    PubMed

    Zhang, Shengkui; Chen, Xin; Lu, Cheng; Ye, Jianqiu; Zou, Meiling; Lu, Kundian; Feng, Subin; Pei, Jinli; Liu, Chen; Zhou, Xincheng; Ma, Ping'an; Li, Zhaogui; Liu, Cuijuan; Liao, Qi; Xia, Zhiqiang; Wang, Wenquan

    2018-01-01

    Cassava ( Manihot esculenta Crantz) is a major tuberous crop produced worldwide. In this study, we sequenced 158 diverse cassava varieties and identified 349,827 single-nucleotide polymorphisms (SNPs) and indels. In each chromosome, the number of SNPs and the physical length of the respective chromosome were in agreement. Population structure analysis indicated that this panel can be divided into three subgroups. Genetic diversity analysis indicated that the average nucleotide diversity of the panel was 1.21 × 10 -4 for all sampled landraces. This average nucleotide diversity was 1.97 × 10 -4 , 1.01 × 10 -4 , and 1.89 × 10 -4 for subgroups 1, 2, and 3, respectively. Genome-wide linkage disequilibrium (LD) analysis demonstrated that the average LD was about ∼8 kb. We evaluated 158 cassava varieties under 11 different environments. Finally, we identified 36 loci that were related to 11 agronomic traits by genome-wide association analyses. Four loci were associated with two traits, and 62 candidate genes were identified in the peak SNP sites. We found that 40 of these genes showed different expression profiles in different tissues. Of the candidate genes related to storage roots, Manes.13G023300, Manes.16G000800, Manes.02G154700, Manes.02G192500, and Manes.09G099100 had higher expression levels in storage roots than in leaf and stem; on the other hand, of the candidate genes related to leaves, Manes.05G164500, Manes.05G164600, Manes.04G057300, Manes.01G202000, and Manes.03G186500 had higher expression levels in leaves than in storage roots and stem. This study provides basis for research on genetics and the genetic improvement of cassava.

  20. Laminated root rot in a western Washington plantation: 8-year mortality and growth of Douglas-fir as related to infected stumps, tree density, and fertilization.

    Treesearch

    Richard E. Miller; Timothy B. Harrington; Walter G. Thies; Jeff. Madsen

    2006-01-01

    A 4-year-old Douglas-fir plantation in the western Washington Cascades was monitored for 8 years after fertilization with potassium (K), nitrogen (N), and K+N to determine fertilizer effects on rates of mortality from laminated root rot (LRR) and other causes relative to a nonfertilized control. Each element was applied at a rate of 300 lb/acre on and around 0.2-acre...

  1. Survey of farmers' knowledge of cassava mosaic disease and their preferences for cassava cultivars in three agro-ecological zones in Benin.

    PubMed

    Houngue, Jerome Anani; Pita, Justin S; Cacaï, Gilles Habib Todjro; Zandjanakou-Tachin, Martine; Abidjo, Emmanuel A E; Ahanhanzo, Corneille

    2018-04-25

    Cassava is an important crop in Africa that is widely cultivated for its starchy tuberous root, which constitutes a major source of dietary carbohydrates. Cassava mosaic disease (CMD) is the most devastating disease affecting cassava in Africa and causes enormous losses in yield. In Benin, specifically, cultivars resistant to CMD are not commonly planted, and even when CMD is observed in fields, farmers do not implement control measures, presumably because they lack proper knowledge and training. Our study aimed to evaluate farmers' knowledge of CMD to determine whether there is consistency between farmers' criteria for selecting cassava cultivars and the currently CMD-recommended cassava varieties. We conducted structured interviews with 369 farmers in 20% of townships in each of three agro-ecological zones in Benin between November 2015 and February 2016. Farmers were selected randomly in each household, and their fields were assessed for CMD incidence and severity. All farmers surveyed, representing a broad demographic pool with regard to education level, age group, and years of experience in cassava production, successfully recognized CMD symptoms in photos, but most (98.60%) said they did not know the causes and vectors of the disease. Most farmers (93.51%) reported that they obtain planting material from neighboring fields or their own fields. In total, 52 unique cultivars were identified, of which 3 (5.76%) were preferred based on their yield and precocity and 3 (5.76%) were preferred based on taste or ability for transformation. The assessment of disease incidence and severity showed that the areas most affected by CMD were Comè Township (37.77% of fields affected) and agro-ecological zone VIII (26.33%). Farmers already know how to recognize the symptoms of CMD and could implement control measures against it if they are trained by researchers. Across all surveyed areas, we identified six preferred cultivars based on the four most commonly stated preference

  2. Prediction of cassava protein interactome based on interolog method.

    PubMed

    Thanasomboon, Ratana; Kalapanulak, Saowalak; Netrphan, Supatcharee; Saithong, Treenut

    2017-12-08

    Cassava is a starchy root crop whose role in food security becomes more significant nowadays. Together with the industrial uses for versatile purposes, demand for cassava starch is continuously growing. However, in-depth study to uncover the mystery of cellular regulation, especially the interaction between proteins, is lacking. To reduce the knowledge gap in protein-protein interaction (PPI), genome-scale PPI network of cassava was constructed using interolog-based method (MePPI-In, available at http://bml.sbi.kmutt.ac.th/ppi ). The network was constructed from the information of seven template plants. The MePPI-In included 90,173 interactions from 7,209 proteins. At least, 39 percent of the total predictions were found with supports from gene/protein expression data, while further co-expression analysis yielded 16 highly promising PPIs. In addition, domain-domain interaction information was employed to increase reliability of the network and guide the search for more groups of promising PPIs. Moreover, the topology and functional content of MePPI-In was similar to the networks of Arabidopsis and rice. The potential contribution of MePPI-In for various applications, such as protein-complex formation and prediction of protein function, was discussed and exemplified. The insights provided by our MePPI-In would hopefully enable us to pursue precise trait improvement in cassava.

  3. Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

    USDA-ARS?s Scientific Manuscript database

    Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

  4. Emergence of a Latent Indian Cassava Mosaic Virus from Cassava Which Recovered from Infection by a Non-Persistent Sri Lankan Cassava Mosaic Virus

    PubMed Central

    Karthikeyan, Chockalingam; Patil, Basavaprabhu L.; Borah, Basanta K.; Resmi, Thulasi R.; Turco, Silvia; Pooggin, Mikhail M.; Hohn, Thomas; Veluthambi, Karuppannan

    2016-01-01

    The major threat for cassava cultivation on the Indian subcontinent is cassava mosaic disease (CMD) caused by cassava mosaic geminiviruses which are bipartite begomoviruses with DNA A and DNA B components. Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) cause CMD in India. Two isolates of SLCMV infected the cassava cultivar Sengutchi in the fields near Malappuram and Thiruvananthapuram cities of Kerala State, India. The Malappuram isolate was persistent when maintained in the Madurai Kamaraj University (MKU, Madurai, Tamil Nadu, India) greenhouse, whereas the Thiruvananthapuram isolate did not persist. The recovered cassava plants with the non-persistent SLCMV, which were maintained vegetative in quarantine in the University of Basel (Basel, Switzerland) greenhouse, displayed re-emergence of CMD after a six-month period. Interestingly, these plants did not carry SLCMV but carried ICMV. It is interpreted that the field-collected, SLCMV-infected cassava plants were co-infected with low levels of ICMV. The loss of SLCMV in recovered cassava plants, under greenhouse conditions, then facilitated the re-emergence of ICMV. The partial dimer clones of the persistent and non-persistent isolates of SLCMV and the re-emerged isolate of ICMV were infective in Nicotiana benthamiana upon agroinoculation. Studies on pseudo-recombination between SLCMV and ICMV in N. benthamiana provided evidence for trans-replication of ICMV DNA B by SLCMV DNA A. PMID:27690084

  5. Mutagenicity and cytotoxicity of liquid waste, press water and pond water, produced in the cassava flour industry, and of antitoxic sodium thiosulfate.

    PubMed

    Viana, Lilian Ávila; Düsman, Elisângela; Vicentini, Veronica Elisa Pimenta

    2014-02-01

    Cassava (Manihot esculenta Crantz), a plant used as food and an ingredient in industry, contains cyanogenic glycosides. The cassava root contains wastewater, popularly known as manipueira, which is a toxic substance. Its ingestion by animals causes poisoning although they react positively to treatment with sodium thiosulfate. The present research evaluates the cytotoxicity and the mutagenicity of liquid waste produced in the process of industrialization of the bitter cassava, olho-junto variety. The liquid wastes are characterized as press water, which is obtained when the cassava roots are pressed; pond water, which is press water stored in impounded ponds; and a solution of sodium thiosulfate, pure and with other waste. The system tests comprised root meristematic cells of Allium cepa L. and bone marrow cells of Rattus norvegicus. Treatment with saline solution was cytotoxic for Allium cepa L. and significantly reduced cell division rate. Although no treatment was cytotoxic in any of the tests with rats, the thiosulfate solution was clastogenic for the chromosomal aberrations test. Since it is harmful to the genetic material submitted within the conditions of current research, sodium thiosulfate should only be used in emergency conditions in which the benefits exceed the risks. © 2013 Society of Chemical Industry.

  6. Biofortification of essential nutritional compounds and trace elements in rice and cassava.

    PubMed

    Sautter, C; Poletti, S; Zhang, P; Gruissem, W

    2006-05-01

    Plant biotechnology can make important contributions to food security and nutritional improvement. For example, the development of 'Golden Rice' by Professor Ingo Potrykus was a milestone in the application of gene technology to deliver both increased nutritional qualities and health improvement to wide sections of the human population. Mineral nutrient and protein deficiency as well as food security remain the most important challenges for developing countries. Current projects are addressing these issues in two major staple crops, cassava (Manihot esculenta Crantz) and rice. The tropical root crop cassava is a major source of food for approximately 600 million of the population worldwide. In sub-Saharan Africa >200 million of the population rely on cassava as their major source of dietary energy. The nutritional quality of the cassava root is not sufficient to meet all dietary needs. Rice is the staple food for half the world population, providing approximately 20% of the per capita energy and 13% of the protein for human consumption worldwide. In many developing countries the dietary contributions of rice are substantially greater (29.3% dietary energy and 29.1% dietary protein). The current six most popular 'mega' rice varieties (in terms of popularity and acreage), including Chinese hybrid rice, have an incomplete amino acid profile and contain limited amounts of essential micronutrients. Rice lines with improved Fe contents have been developed using genes that have functions in Fe absorption, translocation and accumulation in the plant, as well as improved Fe bioavailability in the human intestine. Current developments in biotechnology-assisted plant improvement are reviewed and the potential of the technology in addressing human nutrition and health are discussed.

  7. High-resolution identification and abundance profiling of cassava (Manihot esculenta Crantz) microRNAs.

    PubMed

    Khatabi, Behnam; Arikit, Siwaret; Xia, Rui; Winter, Stephan; Oumar, Doungous; Mongomake, Kone; Meyers, Blake C; Fondong, Vincent N

    2016-01-28

    Small RNAs (sRNAs) are endogenous sRNAs that play regulatory roles in plant growth, development, and biotic and abiotic stress responses. In plants, one subset of sRNAs, microRNAs (miRNAs) exhibit tissue-differential expression and regulate gene expression mainly through direct cleavage of mRNA or indirectly via production of secondary phased siRNAs (phasiRNAs) that silence cognate target transcripts in trans. Here, we have identified cassava (Manihot esculenta Crantz) miRNAs using high resolution sequencing of sRNA libraries from leaf, stem, callus, male and female flower tissues. To analyze the data, we built a cassava genome database and, via sequence analysis and secondary structure prediction, 38 miRNAs not previously reported in cassava were identified. These new cassava miRNAs included two miRNAs not previously been reported in any plant species. The miRNAs exhibited tissue-differential accumulation as confirmed by quantitative RT-PCR and Northern blot analysis, largely reflecting levels observed in sequencing data. Some of the miRNAs identified were predicted to trigger production of secondary phased siRNAs (phasiRNAs) from 80 PHAS loci. Cassava is a woody perennial shrub, grown principally for its starch-rich storage roots, which are rich in calories. In this study, new miRNAs were identified and their expression was validated using qRT-PCR of RNA from five different tissues. The data obtained expand the list of annotated miRNAs and provide additional new resources for cassava improvement research.

  8. The effect of cassava and corn flour utilization on the physicochemical characteristics of cassava leaves snack

    NASA Astrophysics Data System (ADS)

    Ambarsari, I.; Endrasari, R.; Oktaningrum, G. N.

    2018-01-01

    Cassava leaves are nutritious vegetable, but often regarded as an inferior commodity. One of the efforts increasing in the benefit of cassava leaves is through processing it into snack. In order to support the food diversification program and to reduce the dependence on imported commodities, the development of cassava leaves snack could be accompanied by optimizing the use of local materials to minimize the use of wheat flour. The aim of this assessment was to learn the effects of cassava and corn flour substitution on the physicochemical characteristics of cassava-leaves snack. The substitution of local flour (cassava and corn) on the snack production was carried on three levels at 15, 30, and 45%. A control treatment was using 100% wheat flour. The results showed that cassava and corn flour were potential to substitute wheat flour for making cassava-leaves snack. The substitution of cassava and corn flour as much as 45% was able to produce crispy products with a brighter color. The substitution of corn flour was resulting in snacks with the lower content of lipid than the other substitution snacks.

  9. Synthesis of periclinal chimera in cassava.

    PubMed

    Nassar, N M A; Bomfim, N

    2013-02-27

    We provide the first report on the synthesis of a very productive interspecific periclinal chimera of cassava, with large and edible roots. The epidermal tissue of the chimera was formed by the cultivated species Manihot esculenta (E), and the subepidermis and internal tissue were formed by the wild species, Manihot fortalezensis (F). We used cytogenetics and morphological analyses to determine the origins of all tissues. These results may offer potential for the development of new lines for crop improvement based on the use of chimera composed of different combinations of wild species and cultivars.

  10. Biological Control of Phytophthora palmivora Causing Root Rot of Pomelo Using Chaetomium spp.

    PubMed Central

    Wattanachai, Pongnak; Kasem, Soytong; Poaim, Supatta

    2015-01-01

    Phytophthora diseases have become a major impediment in the citrus production in Thailand. In this study, an isolate of Phytophthora denominated as PHY02 was proven to be causal pathogen of root rot of Pomelo (Citrus maxima) in Thailand. The isolate PHY02 was morphologically characterized and identified as Phytophthora palmivora based on molecular analysis of an internal transcribed spacer rDNA sequence. This work also presents in vitro evaluations of the capacities of Chaetomium spp. to control the P. palmivora PHY02. As antagonists, Chaetomium globosum CG05, Chaetomium cupreum CC3003, Chaetomium lucknowense CL01 inhibited 50~61% mycelial growth, degraded mycelia and reduced 92~99% sporangial production of P. palmivora PHY02 in bi-culture test after 30 days. Fungal metabolites from Chaetomium spp. were tested against PHY02. Results showed that, methanol extract of C. globosum CG05 expressed strongest inhibitory effects on mycelial growth and sporangium formation of P. palmivora PHY02 with effective dose ED50 values of 26.5 µg/mL and 2.3 µg/mL, respectively. It is interesting that C. lucknowense is reported for the first time as an effective antagonist against a species of Phytophthora. PMID:25892917

  11. Influence of factors on the drying of cassava in a solar simulator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Njie, D.N.; Rumsey, T.R.

    1997-03-01

    In tropical countries, sun drying is still the most popular method used for processing root and tuber crops like cassava and yam. Relatively very little has been done on studying the kinetics of sun drying a bed of chips of cassava and similar crops, but this information is invaluable in finding options for reducing drying time and costs, and increasing tonnage produced. This project studied some factors that have an effect on the sun drying rate of cassava chips. The factors were ambient temperature, relative humidity, radiation intensity, air velocity, and loading density. A solar simulation chamber was constructed somore » that drying could be achieved under controllable conditions similar to those obtained in sun drying. Experiments carried out in the simulator revealed that temperature had the most significant effect on drying rate, followed by air velocity, and radiation intensity. Regression equations were developed relating the drying rate with the factors studied.« less

  12. Biofortified yellow cassava and vitamin A status of Kenyan children: a randomized controlled trial.

    PubMed

    Talsma, Elise F; Brouwer, Inge D; Verhoef, Hans; Mbera, Gloria N K; Mwangi, Alice M; Demir, Ayşe Y; Maziya-Dixon, Busie; Boy, Erick; Zimmermann, Michael B; Melse-Boonstra, Alida

    2016-01-01

    Whereas conventional white cassava roots are devoid of provitamin A, biofortified yellow varieties are naturally rich in β-carotene, the primary provitamin A carotenoid. We assessed the effect of consuming yellow cassava on serum retinol concentration in Kenyan schoolchildren with marginal vitamin A status. We randomly allocated 342 children aged 5-13 y to receive daily, 6 d/wk, for 18.5 wk 1) white cassava and placebo supplement (control group), 2) provitamin A-rich cassava (mean content: 1460 μg β-carotene/d) and placebo supplement (yellow cassava group), and 3) white cassava and β-carotene supplement (1053 μg/d; β-carotene supplement group). The primary outcome was serum retinol concentration; prespecified secondary outcomes were hemoglobin concentration and serum concentrations of β-carotene, retinol-binding protein, and prealbumin. Groups were compared by using ANCOVA, adjusting for inflammation, baseline serum concentrations of retinol and β-carotene, and stratified design. The baseline prevalence of serum retinol concentration <0.7 μmol/L and inflammation was 27% and 24%, respectively. For children in the control, yellow cassava, and β-carotene supplement groups, the mean daily intake of cassava was 378, 371, and 378 g, respectively, and the total daily supply of provitamin A and vitamin A from diet and supplements was equivalent to 22, 220, and 175 μg retinol, respectively. Both yellow cassava and β-carotene supplementation increased serum retinol concentration by 0.04 μmol/L (95% CI: 0.00, 0.07 μmol/L); correspondingly, serum β-carotene concentration increased by 524% (448%, 608%) and 166% (134%, 202%). We found no effect on hemoglobin concentration or serum concentrations of retinol-binding protein and prealbumin. In our study population, consumption of yellow cassava led to modest gains in serum retinol concentration and a large increase in β-carotene concentration. It can be an efficacious, new approach to improve vitamin A status. This

  13. Survival or productivity? Global synthesis of root and tuber production during drought

    NASA Astrophysics Data System (ADS)

    Daryanto, S.; Wang, L.; Jacinthe, P. A.

    2016-12-01

    According to FAO, there are six major root and tuber crops: potato, cassava, sweet potato, yam, taro, and yautia. Some root and tuber crops (e.g., sweet potato and cassava) are considered to be `drought-resistant', although quantitative evidence that support the premise was still lacking. Greater uncertainties exist on how drought effects co-vary with: 1) soil texture, 2) agro-ecological region, and 3) drought timing. To address these uncertainties, we collected literature data between 1980 and 2015 that reported monoculture root and tuber yield responses to drought under field conditions, and analyzed this large data set using meta-analysis techniques. Our results showed that the amount of water reduction was positively related with yield reduction, but the extent of the impact varied with root or tuber species and the phenological phase during which drought occurred. In contrast to common assumptions regarding drought resistance of certain root and tuber crops, we found that yield reduction was similar between potato and species thought to be `drought-resistant' such as cassava and sweet potato. Here we suggest that drought-resistance in cassava and sweet potato could be more related to survival rather than yield. All roots or tubers crops, however, experienced greater yield reduction when drought occurred during the tuberization period compared to during their vegetative phase. The effect of soil texture as well as region (and related climatic factors) on yield reduction and crop sensitivity were less obvious. Our study provides useful information that could inform agricultural planning, and influence the direction of research for improving the productivity and the resilience of these under-utilized crops in the drought-prone regions of the world.

  14. Performance and meat quality characteristics of broilers fed fermented mixture of grated cassava roots and palm kernel cake as replacement for maize.

    PubMed

    Chukwukaelo, A K; Aladi, N O; Okeudo, N J; Obikaonu, H O; Ogbuewu, I P; Okoli, I C

    2018-03-01

    Performance and meat quality characteristics of broilers fed fermented mixture of grated cassava roots and palm kernel cake (FCP-mix) as a replacement for maize were studied. One hundred and eighty (180), 7-day-old broiler chickens were divided into six groups of 30 birds, and each group replicated thrice. Six experimental diets were formulated for both starter and finisher stages with diets 1 and 6 as controls. Diet 1 contained maize whereas diet 6 contained a 1:1 mixture of cassava root meal (CRM) and palm kernel cake (PKC). In diets 2, 3, 4, and 5, the FCP-mix replaced maize at the rate of 25, 50, 75, and 100%, respectively. Each group was assigned to one experimental diet in a completely randomized design. The proximate compositions of the diets were evaluated. Live weight, feed intake, feed conversion ratio (FCR), carcass weight, and sensory attributes of the meats were obtained from each replicate and data obtained was analyzed statistically. The results showed that live weight, average daily weight gain (ADWG), average daily feed intake (ADFI), and FCR of birds on treatment diets were better than those on the control diets (Diets 1 and 6). The feed cost per kilogram weight gained decreased with inclusion levels of FCP-mix. Birds on diet 1 recorded significantly (p < 0.05) higher dressing percentage than those on the other five treatments. The sensory attributes of the chicken meats were not significantly (p > 0.05) affected by the inclusion of FCP-mix in the diets. FCP-mix is a suitable substitute for maize in broiler diet at a replacement level of up to 100% for best live weight, carcass weight yield, and meat quality.

  15. Physiological and molecular characterization of drought responses and identification of candidate tolerance genes in cassava

    PubMed Central

    Turyagyenda, Laban F.; Kizito, Elizabeth B.; Ferguson, Morag; Baguma, Yona; Agaba, Morris; Harvey, Jagger J. W.; Osiru, David S. O.

    2013-01-01

    Cassava is an important root crop to resource-poor farmers in marginal areas, where its production faces drought stress constraints. Given the difficulties associated with cassava breeding, a molecular understanding of drought tolerance in cassava will help in the identification of markers for use in marker-assisted selection and genes for transgenic improvement of drought tolerance. This study was carried out to identify candidate drought-tolerance genes and expression-based markers of drought stress in cassava. One drought-tolerant (improved variety) and one drought-susceptible (farmer-preferred) cassava landrace were grown in the glasshouse under well-watered and water-stressed conditions. Their morphological, physiological and molecular responses to drought were characterized. Morphological and physiological measurements indicate that the tolerance of the improved variety is based on drought avoidance, through reduction of water loss via partial stomatal closure. Ten genes that have previously been biologically validated as conferring or being associated with drought tolerance in other plant species were confirmed as being drought responsive in cassava. Four genes (MeALDH, MeZFP, MeMSD and MeRD28) were identified as candidate cassava drought-tolerance genes, as they were exclusively up-regulated in the drought-tolerant genotype to comparable levels known to confer drought tolerance in other species. Based on these genes, we hypothesize that the basis of the tolerance at the cellular level is probably through mitigation of the oxidative burst and osmotic adjustment. This study provides an initial characterization of the molecular response of cassava to drought stress resembling field conditions. The drought-responsive genes can now be used as expression-based markers of drought stress tolerance in cassava, and the candidate tolerance genes tested in the context of breeding (as possible quantitative trait loci) and engineering drought tolerance in transgenics

  16. Retention of total carotenoid and β-carotene in yellow sweet cassava (Manihot esculenta Crantz) after domestic cooking

    PubMed Central

    Carvalho, Lucia M. J.; Oliveira, Alcides R. G.; Godoy, Ronoel L. O.; Pacheco, Sidney; Nutti, Marília R.; de Carvalho, José L. V.; Pereira, Elenilda J.; Fukuda, Wânia G.

    2012-01-01

    Background Over the last decade, considerable efforts have been made to identify cassava cultivars to improve the vitamin A nutritional status of undernourished populations, especially in northeast Brazil, where cassava is one of the principal and essentially only nutritional source. Objectives The aim of this study was to evaluate the total carotenoid, β-carotene, and its all-E-, 9-, and 13-Z-β-carotene isomers content in seven yellow sweet cassava roots and their retention after three boiling cooking methods. Design The total carotenoid, β-carotene, and its all-E-, 9-, and 13-Z-β-carotene isomers in yellow sweet cassava samples were determined by ultraviolet/visible spectrometry and high-performance liquid chromatography, respectively, before and after applying the cooking methods. All analyses were performed in triplicate. Results The total carotenoid in raw roots varied from 2.64 to 14.15 µg/g and total β-carotene from 1.99 to 10.32 µg/g. The β-carotene predominated in all the roots. The Híbrido 2003 14 08 cultivar presented the highest β-carotene content after cooking methods 1 and 3. The 1153 – Klainasik cultivar presented the highest 9-Z-β-carotene content after cooking by method 3. The highest total carotenoid retention was observed in cultivar 1456 – Vermelhinha and that of β-carotene for the Híbrido 2003 14 11 cultivar, both after cooking method 1. Evaluating the real retention percentage (RR%) in sweet yellow cassava after home cooking methods showed differences that can be attributed to the total initial carotenoid contents. However, no cooking method uniformly provided a higher total carotenoid or β-carotene retention in all the cultivars. Conclusion Differences were found in the cooking methods among the samples regarding total carotenoid or β-carotene retention, suggesting that the different behaviors of the cultivars need to be further analyzed. However, high percentages of total carotenoid or β-carotene retention were observed

  17. Evaluation of the biocontrol efficacy of a Serratia marcescens strain indigenous to tea rhizosphere for the management of root rot disease in tea

    PubMed Central

    Mangar, Preeti; Saha, Aniruddha

    2018-01-01

    The aim of the present study is to evaluate plant growth promoting and biocontrol efficacy of a Serratia marcescens strain ETR17 isolated from tea rhizosphere for the effective management of root rot disease in tea. Isolated bacterial culture ETR17 showed significant level of in vitro antagonism against nine different foliar and root pathogens of tea. The phenotypic and molecular characterization of ETR17 revealed the identity of the bacterium as Serratia marcescens. The bacterium was found to produce several hydrolytic enzymes like chitinase, protease, lipase, cellulase and plant growth promoting metabolites like IAA and siderophore. Scanning electron microscopic studies on the interaction zone between pathogen and antagonistic bacterial isolate revealed severe deformities in the fungal mycelia. Spectral analyses (LC-ESI-MS, UV-VIS spectrophotometry and HPLC) and TLC indicated the presence of the antibiotics pyrrolnitrin and prodigiosin in the extracellular bacterial culture extracts. Biofilm formation by ETR17 on polystyrene surface was also observed. In vivo application of talc-based formulations prepared with the isolate ETR17 in tea plantlets under green house conditions revealed effective reduction of root-rot disease as well as plant growth promotion to a considerable extent. Viability studies with the ETR17 talc formulation showed the survivability of the isolate up to six months at room temperature. The sustenance of ETR17 (concentration of 8-9x108 cfu g-1) in the soil after the application of talc formulation was recorded by ELISA. Safety studies revealed that ETR17 did not produce hemolysin as observed in pathogenic Serratia strains. The biocontrol strain reported in this study can be used for field application in order to minimize the use of chemical fungicides for disease control in tea gardens. PMID:29466418

  18. Evaluation of the biocontrol efficacy of a Serratia marcescens strain indigenous to tea rhizosphere for the management of root rot disease in tea.

    PubMed

    Dhar Purkayastha, Gargee; Mangar, Preeti; Saha, Aniruddha; Saha, Dipanwita

    2018-01-01

    The aim of the present study is to evaluate plant growth promoting and biocontrol efficacy of a Serratia marcescens strain ETR17 isolated from tea rhizosphere for the effective management of root rot disease in tea. Isolated bacterial culture ETR17 showed significant level of in vitro antagonism against nine different foliar and root pathogens of tea. The phenotypic and molecular characterization of ETR17 revealed the identity of the bacterium as Serratia marcescens. The bacterium was found to produce several hydrolytic enzymes like chitinase, protease, lipase, cellulase and plant growth promoting metabolites like IAA and siderophore. Scanning electron microscopic studies on the interaction zone between pathogen and antagonistic bacterial isolate revealed severe deformities in the fungal mycelia. Spectral analyses (LC-ESI-MS, UV-VIS spectrophotometry and HPLC) and TLC indicated the presence of the antibiotics pyrrolnitrin and prodigiosin in the extracellular bacterial culture extracts. Biofilm formation by ETR17 on polystyrene surface was also observed. In vivo application of talc-based formulations prepared with the isolate ETR17 in tea plantlets under green house conditions revealed effective reduction of root-rot disease as well as plant growth promotion to a considerable extent. Viability studies with the ETR17 talc formulation showed the survivability of the isolate up to six months at room temperature. The sustenance of ETR17 (concentration of 8-9x108 cfu g-1) in the soil after the application of talc formulation was recorded by ELISA. Safety studies revealed that ETR17 did not produce hemolysin as observed in pathogenic Serratia strains. The biocontrol strain reported in this study can be used for field application in order to minimize the use of chemical fungicides for disease control in tea gardens.

  19. Effect of seed pelleting with biocontrol agents on growth and colonisation of roots of mungbean by root-infecting fungi.

    PubMed

    Ramzan, Nadia; Noreen, Nayara; Perveen, Zahida; Shahzad, Saleem

    2016-08-01

    Mungbean (Vigna radiata (L.) Wilczek) is a leguminous pulse crop that is a major source of proteins, vitamins and minerals. Root-infecting fungi produce severe plant diseases like root rot, charcoal rot, damping-off and stem rot. The soil-borne pathogens can be controlled by chemicals, but these chemicals have several negative effects. Use of microbial antagonist such as fungi and bacteria is a safe, effective and eco-friendly method for the control of many soil-borne pathogens. Biological control agents promote plant growth and develop disease resistance. Application of bacteria and fungi as seed dressing suppressed the root-infecting fungi on leguminous crops. Seeds of mungbean were pelleted with different biocontrol agents to determine their effect on plant growth and colonisation of roots by root-infecting fungi, viz. Fusarium solani, Macrophomina phaseolina, Pythium aphanidermatum, Rhizoctonia solani and Sclerotium rolfsii. Treatment of mungbean seeds with fungal antagonists showed more shoot and root length as compared to bacterial antagonists, whereas seed treated with bacterial antagonists showed maximum shoot and root weight. Trichoderma harzianum and Bacillus subtilis were the best among all the biocontrol agents since they provided the highest plant growth and greater reduction in root colonisation by all root-infecting fungi. Bacillus cereus, Trichoderma virens, Pseudomonas fluorescens and Micrococcus varians were also effective against root-infecting fungi but to a lesser extent. T. harzianum, T. virens, B. subtilis and P. fluorescens were found to be best among all biocontrol agents. The root-infecting fungi can be controlled by pelleting seeds with biocontrol agents as it is safe and effective method. Additionally, plant growth was promoted more by this method. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Expression patterns of members of the ethylene signaling-related gene families in response to dehydration stresses in cassava.

    PubMed

    Ren, Meng Yun; Feng, Ren Jun; Shi, Hou Rui; Lu, Li Fang; Yun, Tian Yan; Peng, Ming; Guan, Xiao; Zhang, Heng; Wang, Jing Yi; Zhang, Xi Yan; Li, Cheng Liang; Chen, Yan Jun; He, Peng; Zhang, Yin Dong; Xie, Jiang Hui

    2017-01-01

    Drought is the one of the most important environment stresses that restricts crop yield worldwide. Cassava (Manihot esculenta Crantz) is an important food and energy crop that has many desirable traits such as drought, heat and low nutrients tolerance. However, the mechanisms underlying drought tolerance in cassava are unclear. Ethylene signaling pathway, from the upstream receptors to the downstream transcription factors, plays important roles in environmental stress responses during plant growth and development. In this study, we used bioinformatics approaches to identify and characterize candidate Manihot esculenta ethylene receptor genes and transcription factor genes. Using computational methods, we localized these genes on cassava chromosomes, constructed phylogenetic trees and identified stress-responsive cis-elements within their 5' upstream regions. Additionally, we measured the trehalose and proline contents in cassava fresh leaves after drought, osmotic, and salt stress treatments, and then it was found that the regulation patterns of contents of proline and trehalose in response to various dehydration stresses were differential, or even the opposite, which shows that plant may take different coping strategies to deal with different stresses, when stresses come. Furthermore, expression profiles of these genes in different organs and tissues under non-stress and abiotic stress were investigated through quantitative real-time PCR (qRT-PCR) analyses in cassava. Expression profiles exhibited clear differences among different tissues under non-stress and various dehydration stress conditions. We found that the leaf and tuberous root tissues had the greatest and least responses, respectively, to drought stress through the ethylene signaling pathway in cassava. Moreover, tuber and root tissues had the greatest and least reponses to osmotic and salt stresses through ethylene signaling in cassava, respectively. These results show that these plant tissues had

  1. Expression patterns of members of the ethylene signaling–related gene families in response to dehydration stresses in cassava

    PubMed Central

    Shi, Hou Rui; Lu, Li Fang; Yun, Tian Yan; Peng, Ming; Guan, Xiao; Zhang, Heng; Wang, Jing Yi; Zhang, Xi Yan; Li, Cheng Liang; Chen, Yan Jun; He, Peng; Zhang, Yin Dong; Xie, Jiang Hui

    2017-01-01

    Drought is the one of the most important environment stresses that restricts crop yield worldwide. Cassava (Manihot esculenta Crantz) is an important food and energy crop that has many desirable traits such as drought, heat and low nutrients tolerance. However, the mechanisms underlying drought tolerance in cassava are unclear. Ethylene signaling pathway, from the upstream receptors to the downstream transcription factors, plays important roles in environmental stress responses during plant growth and development. In this study, we used bioinformatics approaches to identify and characterize candidate Manihot esculenta ethylene receptor genes and transcription factor genes. Using computational methods, we localized these genes on cassava chromosomes, constructed phylogenetic trees and identified stress-responsive cis-elements within their 5’ upstream regions. Additionally, we measured the trehalose and proline contents in cassava fresh leaves after drought, osmotic, and salt stress treatments, and then it was found that the regulation patterns of contents of proline and trehalose in response to various dehydration stresses were differential, or even the opposite, which shows that plant may take different coping strategies to deal with different stresses, when stresses come. Furthermore, expression profiles of these genes in different organs and tissues under non-stress and abiotic stress were investigated through quantitative real-time PCR (qRT-PCR) analyses in cassava. Expression profiles exhibited clear differences among different tissues under non-stress and various dehydration stress conditions. We found that the leaf and tuberous root tissues had the greatest and least responses, respectively, to drought stress through the ethylene signaling pathway in cassava. Moreover, tuber and root tissues had the greatest and least reponses to osmotic and salt stresses through ethylene signaling in cassava, respectively. These results show that these plant tissues had

  2. Selecting Native Arbuscular Mycorrhizal Fungi to Promote Cassava Growth and Increase Yield under Field Conditions

    PubMed Central

    Séry, D. Jean-Marc; Kouadjo, Z. G. Claude; Voko, B. R. Rodrigue; Zézé, Adolphe

    2016-01-01

    The use of arbuscular mycorrhizal fungal (AMF) inoculation in sustainable agriculture is now widespread worldwide. Although the use of inoculants consisting of native AMF is highly recommended as an alternative to commercial ones, there is no strategy to allow the selection of efficient fungal species from natural communities. The objective of this study was (i) to select efficient native AMF species (ii) evaluate their impact on nematode and water stresses, and (iii) evaluate their impact on cassava yield, an important food security crop in tropical and subtropical regions. Firstly, native AMF communities associated with cassava rhizospheres in fields were collected from different areas and 7 AMF species were selected, based upon their ubiquity and abundance. Using these criteria, two morphotypes (LBVM01 and LBVM02) out of the seven AMF species selected were persistently dominant when cassava was used as a trap plant. LBVM01 and LBVM02 were identified as Acaulospora colombiana (most abundant) and Ambispora appendicula, respectively, after phylogenetic analyses of LSU-ITS-SSU PCR amplified products. Secondly, the potential of these two native AMF species to promote growth and enhance tolerance to root-knot nematode and water stresses of cassava (Yavo variety) was evaluated using single and dual inoculation in greenhouse conditions. Of the two AMF species, it was shown that A. colombiana significantly improved the growth of the cassava and enhanced tolerance to water stress. However, both A. colombiana and A. appendicula conferred bioprotective effects to cassava plants against the nematode Meloidogyne spp., ranging from resistance (suppression or reduction of the nematode reproduction) or tolerance (low or no suppression in cassava growth). Thirdly, the potential of these selected native AMF to improve cassava growth and yield was evaluated under field conditions, compared to a commercial inoculant. In these conditions, the A. colombiana single inoculation and the

  3. Impact of motility and chemotaxis features of the rhizobacterium Pseudomonas chlororaphis PCL1606 on its biocontrol of avocado white root rot.

    PubMed

    Polonio, Álvaro; Vida, Carmen; de Vicente, Antonio; Cazorla, Francisco M

    2017-06-01

    The biocontrol rhizobacterium Pseudomonas chlororaphis PCL1606 has the ability to protect avocado plants against white root rot produced by the phytopathogenic fungus Rosellinia necatrix. Moreover, PCL1606 displayed direct interactions with avocado roots and the pathogenic fungus. Thus, nonmotile (flgK mutant) and non-chemotactic (cheA mutant) derivatives of PCL1606 were constructed to emphasize the importance of motility and chemotaxis in the biological behaviour of PCL1606 during the biocontrol interaction. Plate chemotaxis assay showed that PCL1606 was attracted to the single compounds tested, such as glucose, glutamate, succinate, aspartate and malate, but no chemotaxis was observed to avocado or R. necatrix exudates. Using the more sensitive capillary assay, it was reported that smaller concentrations (1 mM) of single compounds elicited high chemotactic responses, and strong attraction was confirmed to avocado and R. necatrix exudates. Finally, biocontrol experiments revealed that the cheA and fglK derivative mutants reduced root protection against R. necatrix, suggesting an important role for these biological traits in biocontrol by P. chlororaphis PCL1606. [Int Microbiol 20(2):94-104 (2017)]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  4. [Fuel ethanol production from cassava feedstock].

    PubMed

    Huang, Ribo; Chen, Dong; Wang, Qingyan; Shen, Naikun; Wei, Yutuo; Du, Liqin

    2010-07-01

    The regions suitable for growing cassava include five provinces in Southern China, with Guangxi alone accounting for over 65% of the total cassava production in the country. In this article, the state-of-the-art development of fuel ethanol production from cassava in China is illustrated by the construction of the cassava fuel ethanol plant with its annual production capacity of 200 000 metric tons. And in the meantime, problems and challenges encountered in the development of China's cassava fuel ethanol are highlighted and the strategies to address them are proposed.

  5. 605 Salad crops: Root, bulb, and tuber Crops

    USDA-ARS?s Scientific Manuscript database

    Root and tuber crops (potato, cassava, sweet potato, and yams) comprise 4 of the 10 major food staples of the world and serve as a major source of energy for the poor of developing nations. Minimal strain placed on agro ecosystems by root and tuber crops highlight their welcomed contribution to the ...

  6. Genome-Wide Identification, Expression, and Functional Analysis of the Sugar Transporter Gene Family in Cassava (Manihot esculenta).

    PubMed

    Liu, Qin; Dang, Huijie; Chen, Zhijian; Wu, Junzheng; Chen, Yinhua; Chen, Songbi; Luo, Lijuan

    2018-03-26

    The sugar transporter ( STP ) gene family encodes monosaccharide transporters that contain 12 transmembrane domains and belong to the major facilitator superfamily. STP genes play critical roles in monosaccharide distribution and participate in diverse plant metabolic processes. To investigate the potential roles of STPs in cassava ( Manihot esculenta ) tuber root growth, genome-wide identification and expression and functional analyses of the STP gene family were performed in this study. A total of 20 MeSTP genes ( MeSTP1 - 20 ) containing the Sugar_tr conserved motifs were identified from the cassava genome, which could be further classified into four distinct groups in the phylogenetic tree. The expression profiles of the MeSTP genes explored using RNA-seq data showed that most of the MeSTP genes exhibited tissue-specific expression, and 15 out of 20 MeSTP genes were mainly expressed in the early storage root of cassava. qRT-PCR analysis further confirmed that most of the MeSTPs displayed higher expression in roots after 30 and 40 days of growth, suggesting that these genes may be involved in the early growth of tuber roots. Although all the MeSTP proteins exhibited plasma membrane localization, variations in monosaccharide transport activity were found through a complementation analysis in a yeast ( Saccharomyces cerevisiae ) mutant, defective in monosaccharide uptake. Among them, MeSTP2, MeSTP15, and MeSTP19 were able to efficiently complement the uptake of five monosaccharides in the yeast mutant, while MeSTP3 and MeSTP16 only grew on medium containing galactose, suggesting that these two MeSTP proteins are transporters specific for galactose. This study provides significant insights into the potential functions of MeSTPs in early tuber root growth, which possibly involves the regulation of monosaccharide distribution.

  7. Effect of chemical and mechanical weed control on cassava yield, soil quality and erosion under cassava cropping system

    NASA Astrophysics Data System (ADS)

    Islami, Titiek; Wisnubroto, Erwin; Utomo, Wani

    2016-04-01

    Three years field experiments were conducted to study the effect of chemical and mechanical weed control on soil quality and erosion under cassava cropping system. The experiment were conducted at University Brawijaya field experimental station, Jatikerto, Malang, Indonesia. The experiments were carried out from 2011 - 2014. The treatments consist of three cropping system (cassava mono culture; cassava + maize intercropping and cassava + peanut intercropping), and two weed control method (chemical and mechanical methods). The experimental result showed that the yield of cassava first year and second year did not influenced by weed control method and cropping system. However, the third year yield of cassava was influence by weed control method and cropping system. The cassava yield planted in cassava + maize intercropping system with chemical weed control methods was only 24 t/ha, which lower compared to other treatments, even with that of the same cropping system used mechanical weed control. The highest cassava yield in third year was obtained by cassava + peanuts cropping system with mechanical weed control method. After three years experiment, the soil of cassava monoculture system with chemical weed control method possessed the lowest soil organic matter, and soil aggregate stability. During three years of cropping soil erosion in chemical weed control method, especially on cassava monoculture, was higher compared to mechanical weed control method. The soil loss from chemical control method were 40 t/ha, 44 t/ha and 54 t/ha for the first, second and third year crop. The soil loss from mechanical weed control method for the same years was: 36 t/ha, 36 t/ha and 38 t/ha. Key words: herbicide, intercropping, soil organic matter, aggregate stability.

  8. Variation in cassava germplasm for tolerance to post-harvest physiological deterioration.

    PubMed

    Venturini, M T; Santos, L R; Vildoso, C I A; Santos, V S; Oliveira, E J

    2016-05-06

    Tolerant varieties can effectively control post-harvest physiological deterioration (PPD) of cassava, although knowledge on the genetic variability and inheritance of this trait is needed. The objective of this study was to estimate genetic parameters and identify sources of tolerance to PPD and their stability in cassava accessions. Roots from 418 cassava accessions, grown in four independent experiments, were evaluated for PPD tolerance 0, 2, 5, and 10 days post-harvest. Data were transformed into area under the PPD-progress curve (AUP-PPD) to quantify tolerance. Genetic parameters, stability (Si), adaptability (Ai), and the joint analysis of stability and adaptability (Zi) were obtained via residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) methods. Variance in the genotype (G) x environment (E) interaction and genotypic variance were important for PPD tolerance. Individual broad-sense heritability (hg(2)= 0.38 ± 0.04) and average heritability in accessions (hmg(2)= 0.52) showed high genetic control of PPD tolerance. Genotypic correlation of AUP-PPD in different experiments was of medium magnitude (ȓgA = 0.42), indicating significant G x E interaction. The predicted genotypic values o f G x E free of interaction (û + ĝi) showed high variation. Of the 30 accessions with high Zi, 19 were common to û + ĝi, Si, and Ai parameters. The genetic gain with selection of these 19 cassava accessions was -55.94, -466.86, -397.72, and -444.03% for û + ĝi, Si, Ai, and Zi, respectively, compared with the overall mean for each parameter. These results demonstrate the variability and potential of cassava germplasm to introduce PPD tolerance in commercial varieties.

  9. A socio-scientific analysis of the environmental and health benefits as well as potential risks of cassava production and consumption.

    PubMed

    Mombo, S; Dumat, C; Shahid, M; Schreck, E

    2017-02-01

    Due to its high adaptability, cassava (Manihot esculenta Crantz) is one of the world's most cultivated and consumed plants after maize and rice. However, there are relatively few scientific studies on this important crop. The objective of this review was therefore to summarize and discuss the available information on cassava cropping in order to promote sustainable practices in terms of production and consumption. Cassava cultivation has been expanding recently at the global scale and is widely consumed in most regions of South America, Africa, and Asia. However, it is also characterized by the presence in its roots of potentially toxic hydrocyanic acid. Furthermore, cassava can also absorb pollutants as it is currently cultivated near roads or factories and generally without consideration for potential sources of soil, water, or atmospheric pollution. Careful washing, peeling, and adequate preparation before eating are therefore crucial steps for reducing human exposure to both environmental pollutants and natural hydrocyanic acid. At present, there is not enough precise data available on this staple food crop. To improve our knowledge on the nutritive benefits versus health risks associated with cassava consumption, further research is necessary to compare cassava cultivars and precisely study the influence of preparation methods.

  10. Reducing cassava toxicity by heap-fermentation in Uganda.

    PubMed

    Essers, A J; Ebong, C; van der Grift, R M; Nout, M J; Otim-Nape, W; Rosling, H

    1995-05-01

    Processing of cassava roots by the Alur tribe in Uganda includes a stage of solid substrate fermentation in heaps. Changes in cyanogen levels during the process, microflora involved, and protein levels, amino acid patterns and mycotoxin contamination of the final products were studied. Processing was monitored at six rural households and repeated at laboratory site, comparing it to sun-drying. Flour samples from rural households were analysed for residual cyanogens, mutagenicity, cytotoxicity and aflatoxins. Mean (+/- SD) total cyanogen levels in flours collected at rural households were 20.3 (+/- 16.8) mg CN equivalents kg-1 dry weight in 1990 (n = 23) and 65.7 (+/- 56.7) in 1992 (n = 21). Mean (+/- SD) levels of cyanohydrins plus HCN were 9.1 (+/- 8.7) in the 1992 flours. Total cyanogen levels in the village monitored batches were reduced considerably by heap-fermentation from 436.3 (+/- 140.7) to 20.4 (+/- 14.0) mg CN equivalents kg-1 dry weight cassava. Residual cyanogen levels were positively correlated with particle size of the resulting crumbs. Heap-fermentation was significantly more effective in reducing cyanogen levels than sun-drying alone, but did not always result in innocuous levels of of cyanogens. Dominant mycelial growth was from the fungi Neurospora sitophila, Geotrichum candidum and Rhizopus oryzae. No mutagenicity, cytotoxicity nor aflatoxins could be detected in the flours. Protein quantity and quality were not significantly reduced. Cassava gel viscosity pattern was modified to the consumers' preference by this method. As the removal of cyanogens was more efficient and we found no new obvious health risk, heap-fermentation can be regarded as an improvement compared to sun-drying alone in areas where cassava varieties with higher cyanogen levels prevail, but we recommend optimisation of the process for ensuring still safer products.

  11. Integrated management of foot rot of lentil using biocontrol agents under field condition.

    PubMed

    Hannan, M A; Hasan, M M; Hossain, I; Rahman, S M E; Ismail, Alhazmi Mohammed; Oh, Deog-Hwan

    2012-07-01

    The efficacy of cowdung, Bangladesh Institute of Nuclear Agriculture (BINA)-biofertilizer, and Bangladesh Agricultural University (BAU)-biofungicide, alone or in combination, was evaluated for controlling foot rot disease of lentil. The results exhibited that BINA-biofertilizer and BAUbiofungicide (peat soil-based Rhizobium leguminosarum and black gram bran-based Trichoderma harzianum) are compatible and have combined effects in controlling the pathogenic fungi Fusarium oxysporum and Sclerotium rolfsii, which cause the root rot of lentil. Cowdung mixing with soil (at 5 t/ha) during final land preparation and seed coating with BINA-biofertilizer and BAU-biofungicide (at 2.5% of seed weight) before sowing recorded 81.50% field emergence of lentil, which showed up to 19.85% higher field emergence over the control. Post-emergence deaths of plants due to foot rot disease were significantly reduced after combined seed treatment with BINA-biofertilizer and BAU-biofungicide. Among the treatments used, only BAU-biofungicide as the seed treating agent resulted in higher plant stand (84.82%). Use of BINA-biofertilizer and BAU-biofungicide as seed treating biocontrol agents and application of cowdung in the soil as an organic source of nutrient resulted in higher shoot and root lengths, and dry shoot and root weights of lentil. BINA-biofertilizer significantly increased the number of nodules per plant and nodules weight of lentil. Seeds treating with BAUbiofungicide and BINA-biofertilizer and soil amendment with cowdung increased the biomass production of lentil up to 75.56% over the control.

  12. Genome-wide characterization and expression analysis enables identification of abiotic stress-responsive MYB transcription factors in cassava (Manihot esculenta).

    PubMed

    Ruan, Meng-Bin; Guo, Xin; Wang, Bin; Yang, Yi-Ling; Li, Wen-Qi; Yu, Xiao-Ling; Zhang, Peng; Peng, Ming

    2017-06-15

    The myeloblastosis (MYB) transcription factor superfamily is the largest transcription factor family in plants, playing different roles during stress response. However, abiotic stress-responsive MYB transcription factors have not been systematically studied in cassava (Manihot esculenta), an important tropical tuber root crop. In this study, we used a genome-wide transcriptome analysis to predict 299 putative MeMYB genes in the cassava genome. Under drought and cold stresses, many MeMYB genes exhibited different expression patterns in cassava leaves, indicating that these genes might play a role in abiotic stress responses. We found that several stress-responsive MeMYB genes responded to abscisic acid (ABA) in cassava leaves. We characterize four MeMYBs, namely MeMYB1, MeMYB2, MeMYB4, and MeMYB9, as R2R3-MYB transcription factors. Furthermore, RNAi-driven repression of MeMYB2 resulted in drought and cold tolerance in transgenic cassava. Gene expression assays in wild-type and MeMYB2-RNAi cassava plants revealed that MeMYB2 may affect other MeMYBs as well as MeWRKYs under drought and cold stress, suggesting crosstalk between MYB and WRKY family genes under stress conditions in cassava. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Cassava processing, consumption, and cyanide toxicity.

    PubMed

    Adewusi, S R; Akindahunsi, A A

    1994-09-01

    The frequency of cassava consumption was investigated among three groups of people representing students from traditional and nontraditional cassava-consuming environments and cassava processors. Of these, 64% of the students at Obafemi Awolowo University, Ile-Ife, 38% of those at the Federal University of Technology, Akure, and 44% of the cassava processors consumed cassava products at least once a day, while 4, 35, and 28% of the groups, respectively, were moderate consumers (4-6 times a week). The serum thiocyanate level of the processors was significantly higher (0.57 mg/dl) than those of the students (0.38 mg/dl), but there was no significant difference in the urinary thiocyanate level of the three groups. Analysis of cassava and its intermediate and final products for free cyanide, acetone cyanohydrin, and intact glucosides during the production of such cassava products as gari, fufu, and lafun revealed that while the finished products might be safe for human consumption, the workers were probably exposed at different stages of processing to nondietary sources of cyanide.

  14. Health effects of cassava consumption in south Ethiopia.

    PubMed

    Abuye, C; Kelbessa, U; Wolde-Gebriel, S

    1998-03-01

    Health problems associated with cassava consumption was studied in three villages (Kodowono, Lotte and Woidewashe) of Gamo-Gofa, South Ethiopia. Total goitre rate (% TGR) increased with increasing rate of cassava consumption while, urinary iodine excretion (UIE) was found to be in the normal value range for the three villages. In both males and females incidence of goitre after the introduction of cassava to Kodowono village was significantly higher than before introduction of cassava (p < 0.001). This may indicate that the high rate of goitre is attributed to the frequency of cassava consumption. Of 450 individuals interviewed for health problems associated with cassava meal consumption, 50% reported that they were suffering from epigastric burning pain and dizziness while 38.7% reported abdominal distention and vomiting. Vomiting was relatively higher in the age group 20 years and below than it was in those above 20 years of age. These problems may be attributed to cassava consumption because, cassava contains cyanide which results in intoxication when poorly processed cassava meal is taken. Goitre prevalence and health problems attributed to cassava consumption therefore, necessitate an intervention programme to control iodine deficiency disorders (IDD), develop appropriate processing techniques to eliminate cassava toxicity and educate villagers on how to prepare safer meals from cassava.

  15. Impact of style of processing on retention and bioaccessibility of beta-carotene in cassava (Manihot esculanta, Crantz).

    PubMed

    Thakkar, Sagar K; Huo, Tianyao; Maziya-Dixon, Bussie; Failla, Mark L

    2009-02-25

    We previously demonstrated that the quantity of beta-carotene (BC) partitioning in mixed micelles during simulated small intestinal digestion, i.e., the bioaccessibility, of boiled cassava is highly correlated with the BC content of different cultivars. However, cassava is also traditionally prepared by fermentation and roasting. These different methods of preparation have the potential to affect both the retention and bioaccessibility of BC. Here, we first compared retention of BC in boiled cassava, gari (fermentation followed by roasting), and fufu (fermentation followed by sieving and cooking into a paste) prepared from roots of three cultivars. BC content in unprocessed cultivars ranged from 6-8 microg/g wet weight, with cis isomers accounting for approximately one-third of total BC. Apparent retention of BC was approximately 90% for boiled cassava and fufu. In contrast, roasting fermented cassava at 195 degrees C for 20 min to prepare gari decreased BC content by 90%. Retention was increased to 63% when temperature was decreased to 165 degrees C and roasting was limited to 10 min. Processing was also associated with a decline in all-trans-BC and concomitant increase in 13-cis-BC. The efficiency of micellarization of all-trans and cis isomers of BC during simulated digestion was 25-30% for boiled cassava and gari and independent of cultivar. However, micellarization of BC isomers during digestion of fufu was only 12-15% (P < 0.05). These differences in retention and bioaccessibility of BC from cassava products prepared according to traditional processing methods suggest that gari and fufu may provide less retinol activity equivalents than isocaloric intake of boiled cassava.

  16. Genome-wide analysis of aquaporin gene family and their responses to water-deficit stress conditions in cassava.

    PubMed

    Putpeerawit, Pattaranit; Sojikul, Punchapat; Thitamadee, Siripong; Narangajavana, Jarunya

    2017-12-01

    Cassava (Manihot esculenta Crantz) is an important economic crop in tropical countries. Although cassava is considered a drought-tolerant crop that can grow in arid areas, the impact of drought can significantly reduce the growth and yield of cassava storage roots. The discovery of aquaporin molecules (AQPs) in plants has resulted in a paradigm shift in the understanding of plant-water relationships, whereas the relationship between aquaporin and drought resistance in cassava still remains elusive. To investigate the potential role of aquaporin in cassava under water-deficit conditions, 45 putative MeAQPs were identified in the cassava genome. Six members of MeAQPs, containing high numbers of water stress-responsive motifs in their promoter regions, were selected for a gene expression study. Two cassava cultivars, which showed different degrees of responses to water-deficit stress, were used to test in in vitro and potted plant systems. The differential expression of all candidate MeAQPs were found in only leaves from the potted plant system were consistent with the relative water content and with the stomatal closure profile of the two cultivars. MePIP2-1 and MePIP2-10 were up-regulated and this change in their expression might regulate a special signal for water efflux out of guard cells, thus inducing stomatal closure under water-deficit conditions. In addition, the expression profiles of genes in the ABA-dependent pathway revealed an essential correlation with stomatal closure. The potential functions of MeAQPs and candidate ABA-dependent pathway genes in response to water deficit in the more tolerant cassava cultivar were discussed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Resistance mechanisms to toxin-mediated charcoal rot infection in maturity group III soybean: role of seed phenol lignin soflavones sugars and seed minerals in charcoal rot resistance

    USDA-ARS?s Scientific Manuscript database

    Charcoal rot is a disease caused by the fungus Macrophomina phaseolina (Tassi) Goid, and thought to infect the plants through roots by a toxin-mediated mechanism, resulting in yield loss and poor seed quality, especially under drought conditions. The mechanism by which this infection occurs is not y...

  18. Comparison of leaf proteomes of cassava (Manihot esculenta Crantz) cultivar NZ199 diploid and autotetraploid genotypes.

    PubMed

    An, Feifei; Fan, Jie; Li, Jun; Li, Qing X; Li, Kaimian; Zhu, Wenli; Wen, Feng; Carvalho, Luiz J C B; Chen, Songbi

    2014-01-01

    Cassava polyploid breeding has drastically improved our knowledge on increasing root yield and its significant tolerance to stresses. In polyploid cassava plants, increases in DNA content highly affect cell volumes and anatomical structures. However, the mechanism of this effect is poorly understood. The purpose of the present study was to compare and validate the changes between cassava cultivar NZ199 diploid and autotetraploid at proteomic levels. The results showed that leaf proteome of cassava cultivar NZ199 diploid was clearly differentiated from its autotetraploid genotype using 2-DE combined MS technique. Sixty-five differential protein spots were seen in 2-DE image of autotetraploid genotype in comparison with that of diploid. Fifty-two proteins were identified by MALDI-TOF-MS/MS, of which 47 were up-regulated and 5 were down-regulated in autotetraploid genotype compared with diploid genotype. The classified functions of 32 up-regulated proteins were associated with photosynthesis, defense system, hydrocyanic acid (HCN) metabolism, protein biosynthesis, chaperones, amino acid metabolism and signal transduction. The remarkable variation in photosynthetic activity, HCN content and resistance to salt stress between diploid and autotetraploid genotypes is closely linked with expression levels of proteomic profiles. The analysis of protein interaction networks indicated there are direct interactions between the 15 up-regulation proteins involved in the pathways described above. This work provides an insight into understanding the protein regulation mechanism of cassava polyploid genotype, and gives a clue to improve cassava polyploidy breeding in increasing photosynthesis and resistance efficiencies.

  19. [Antagonism of Trichoderma spp. to fungi caused root rot of Sophora tonkinensis].

    PubMed

    Qin, Liu-yan; Jiang, Ni; Tang, Mei-qiong; Miao, Jian-hua; Li, Lin-xuan

    2011-04-01

    To study the antagonism of Trichoderma spp. to fungi S9(Fusarium solani)which caused root rot of Sophora tonkinensis and discuss the further develop prospects of microbial biological control in soil-borne diseases on Chinese herbal medicines. Antagonism of H2 (Trichoderma harsianum), M6 (Trichoderma viride) and K1 (Trichoderma koningii) to Fusarium solani were researched by growth rate and confront culture. And their mechanisms were discussed. H2 and M6 had obvious competitive advantage, the growth rate of which were 1.43-2.72 times and 1.43-1.95 times as S9 respectively. The space competitive advantage of K1 was relatively weak; the growth rate was slower than S9. The antagonism of three species of Trichoderma spp. to S9 was in varying degrees. The antagonism to S9 of M6 and H2 was better,the inhibition rate were 100% and 82.35% respectively, even cultivated S9 for three days in advance. And their inhibition indexes were both reached class I. The inhibition index and inhibition rate of K1 was respectively 46.36% and class IV. The Trichoderma spp. could cause S9 mycelium to appear some phenomenon just like fracture, constriction reduced, digestion, etc. which were observed under the microscope. Trichoderma harsianum and Trichoderma viride showed the further develop prospects in the fight against soil-borne disease on Chinese herbal medicines.

  20. Cassava diet--a cause for mucopolysaccharidosis?

    PubMed

    Sreeja, V G; Leelamma, S

    2002-01-01

    Studies were carried out to determine the changes in glycosaminnoglycan (GAG) metabolism in rats fed cassava with varying cyanoglucoside levels and two levels of protein. Results indicated that there was an enhancement in the level of total and individual GAG with a corresponding reduction in the activity of enzymes involved in the degradation of glycosaminoglycan. These changes were significant for rats given a cassava diet (raw and boiled cassava) and low protein. The changes in total and individual GAG and the decrease in the activity of degrading enzymes was more for high cyanide (raw cassava) groups compared with other groups showing that consumption of untreated cassava is an additive factor for the promotion of mucopolysaccharidosis.

  1. Marker-Based Estimates Reveal Significant Non-additive Effects in Clonally Propagated Cassava (Manihot esculenta): Implications for the Prediction of Total Genetic Value and the Selection of Varieties.

    PubMed

    Wolfe, Marnin D; Kulakow, Peter; Rabbi, Ismail Y; Jannink, Jean-Luc

    2016-08-31

    In clonally propagated crops, non-additive genetic effects can be effectively exploited by the identification of superior genetic individuals as varieties. Cassava (Manihot esculenta Crantz) is a clonally propagated staple food crop that feeds hundreds of millions. We quantified the amount and nature of non-additive genetic variation for three key traits in a breeding population of cassava from sub-Saharan Africa using additive and non-additive genome-wide marker-based relationship matrices. We then assessed the accuracy of genomic prediction for total (additive plus non-additive) genetic value. We confirmed previous findings based on diallel populations, that non-additive genetic variation is significant for key cassava traits. Specifically, we found that dominance is particularly important for root yield and epistasis contributes strongly to variation in CMD resistance. Further, we showed that total genetic value predicted observed phenotypes more accurately than additive only models for root yield but not for dry matter content, which is mostly additive or for CMD resistance, which has high narrow-sense heritability. We address the implication of these results for cassava breeding and put our work in the context of previous results in cassava, and other plant and animal species. Copyright © 2016 Author et al.

  2. Cassava virus diseases: biology, epidemiology, and management.

    PubMed

    Legg, James P; Lava Kumar, P; Makeshkumar, T; Tripathi, Leena; Ferguson, Morag; Kanju, Edward; Ntawuruhunga, Pheneas; Cuellar, Wilmer

    2015-01-01

    Cassava (Manihot esculenta Crantz.) is the most important vegetatively propagated food staple in Africa and a prominent industrial crop in Latin America and Asia. Its vegetative propagation through stem cuttings has many advantages, but deleteriously it means that pathogens are passed from one generation to the next and can easily accumulate, threatening cassava production. Cassava-growing continents are characterized by specific suites of viruses that affect cassava and pose particular threats. Of major concern, causing large and increasing economic impact in Africa and Asia are the cassava mosaic geminiviruses that cause cassava mosaic disease in Africa and Asia and cassava brown streak viruses causing cassava brown streak disease in Africa. Latin America, the center of origin and domestication of the crop, hosts a diverse set of virus species, of which the most economically important give rise to cassava frog skin disease syndrome. Here, we review current knowledge on the biology, epidemiology, and control of the most economically important groups of viruses in relation to both farming and cultural practices. Components of virus control strategies examined include: diagnostics and surveillance, prevention and control of infection using phytosanitation, and control of disease through the breeding and promotion of varieties that inhibit virus replication and/or movement. We highlight areas that need further research attention and conclude by examining the likely future global outlook for virus disease management in cassava. © 2015 Elsevier Inc. All rights reserved.

  3. Spatial Heterogeneity of SOM Concentrations Associated with White-rot Versus Brown-rot Wood Decay.

    PubMed

    Bai, Zhen; Ma, Qiang; Dai, Yucheng; Yuan, Haisheng; Ye, Ji; Yu, Wantai

    2017-10-23

    White- and brown-rot fungal decay via distinct pathways imparts characteristic molecular imprints on decomposing wood. However, the effect that a specific wood-rotting type of fungus has on proximal soil organic matter (SOM) accumulation remains unexplored. We investigated the potential influence of white- and brown-rot fungi-decayed Abies nephrolepis logs on forest SOM stocks (i.e., soil total carbon (C) and nitrogen (N)) and the concentrations of amino sugars (microbial necromass) at different depths and horizontal distances from decaying woody debris. The brown-rot fungal wood decay resulted in higher concentrations of soil C and N and a greater increase in microbial necromass (i.e., 1.3- to 1.7-fold greater) than the white-rot fungal wood decay. The white-rot sets were accompanied by significant differences in the proportions of the bacterial residue index (muramic acid%) with soil depth; however, the brown-rot-associated soils showed complementary shifts, primarily in fungal necromass, across horizontal distances. Soil C and N concentrations were significantly correlated with fungal rather than bacterial necromass in the brown-rot systems. Our findings confirmed that the brown-rot fungi-dominated degradation of lignocellulosic residues resulted in a greater SOM buildup than the white-rot fungi-dominated degradation.

  4. Soil-to-cassava transfer of naturally occurring radionuclides from communities along Ghana's oil and gas rich Tano Basin.

    PubMed

    Doyi, Israel Nutifafa Yawo; Essumang, David Kofi; Agyapong, Asare Kwaku; Asumadu-Sarkodie, Samuel

    2018-02-01

    Soil-to-plant transfer factor (TF) is widely used to assess the impact of soil radioactivity on agricultural crops. The root crop cassava (Manihot esculenta) provides 30%-50% of the calories consumed in Sub-Saharan Africa and is widely used in South America. γ-ray analysis was used to measure activity concentrations of 238 U, 232 Th, and 40 K in cassava root and soil. The TF values for 238 U, 232 Th, and 40 K were in the range 0.06-0.12, 0.01-0.10 and 0.04-0.28 respectively. The median transfer factors were 0.10 ( 238 U), 0.04 ( 232 Th) and 0.08 ( 40 K). For 238 U and 232 Th, the highest TF values were 0.12 and 0.10 respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Spatial distribution of mercury and arsenic levels in water, soil and cassava plants in a community with long history of gold mining in Tanzania.

    PubMed

    Nyanza, Elias C; Dewey, Deborah; Thomas, Deborah S K; Davey, Mark; Ngallaba, Sospatro E

    2014-12-01

    This study examined the spatial distribution of total mercury (THg) and total arsenic (TAs) in water, soil and cassava (Manihot esculenta) (leaves and roots) samples taken from areas in Rwamagasa village in northwestern Tanzania where daily living activities occur in close proximity to extensive artisanal and small scale gold mining. Results indicated that 33.3 % of the water sources had THg levels above the WHO guideline of 1.0 µg/L for safe drinking water, and 12.5 % had TAs levels above 10 µg/L. Cassava leaves were found to have higher THg (ranging from 8.3 to 167 µg/kg) and TAs (ranging from 60 to 1,120 µg/kg) levels than cassava roots, which ranged between 1.2-8.3 µg/kg for THg and 25-310 µg/kg for TAs. Concentrations of THg and TAs in soil samples ranged between 5.8-1,759 and 183-20,298 µg/kg, respectively. Both THg and TAs were found to be distributed throughout Rwamagasa village.

  6. Allocative Efficiency Analysys Production Function Of Cassava Farming (Manihot, Sp.) In Tenayan Raya Sub-District Of Pekanbaru City

    NASA Astrophysics Data System (ADS)

    Nizar, Rini; Nurwati, Niken; Amalia

    2017-12-01

    Cassava (Manihot sp) has long been known and cultivated by Indonesian farmers. The economic and social potential of cassava aside from foodstuffs can also be used as raw materials for industrial use and animal feed. In Riau Province, Cassva has the potential to be developed considering Cassva is a plant that can easily grow on low altitude to high altitude lands. Cassava does not need a complex maintenance. Conventionally, this plant can be planted and left alone by itself. Cassava roots can be developed to be a processed products that society needs as main foodstuffs ingredients. This research is done in three months and the purpose is to know the influence of input use (pesticide, seeds, fertilizers and labor) on cassava farming to cassava farming by the model of cobb-douglas. Other than that is also the effect on economical efficiency. The method used in this research is a quantitative research by using Cobb-Douglas Function Model. This research was done in the Tenayan Raya sub-district with 55 farmer samples. This research shows Cobb-Douglas Production Function can be used as the predictor for Cassava production function in Tenayan Raya Sub-district of Pekanbaru City. Altogether the production factor used by farmers influence production. Partially only usage of organic fertilizer that does not affect production, while other production factor such as, seeds, pesticides, an-organic fertilizer (urea) and labor affect production by quite a bit. Usage of production factor seeds, urea and pesticides is not yet efficient while usage of organic fertilizer is not efficient and usage of labor on cassava agriculture by respondent farmers is relatively efficient

  7. Genetic inheritance of pulp colour and selected traits of cassava (Manihot esculenta Crantz) at early generation selection.

    PubMed

    Nduwumuremyi, Athanase; Melis, Rob; Shanahan, Paul; Theodore, Asiimwe

    2018-06-01

    The early generation selection of cassava quantitative and qualitative traits saves breeding resources as it can shorten breeding schemes. Inheritance analysis provides important breeding information for developing new improved varieties. This study aimed at developing an F1 segregating cassava population and determining mode of gene action of pulp colour and selected traits at early generation selection (F1 seedling and clones). The 15 families exhibited significant (P < 0.05) phenotypic variation between offspring. The general combining ability (GCA) was significant for all traits except cassava brown streak disease on leaves, whereas specific combining ability (SCA) was significant for all evaluated traits. The Garukansubire and Gitamisi genotypes were the best general combiners for improving fresh storage root yield, while G1 and G2 were the best general combiners for improved carotenoid (yellow/orange pulp colour) and delayed physiological postharvest deterioration. The pulp colour had the highest GCA/SCA ratio and percent sum of squares due to GCA. The 15 F1 families exhibited essential genetic diversity for cassava improvement. The expression of most cassava traits was controlled by both additive and non-additive gene action. The study elucidated the role of dominance effects over the additive effects for the evaluated traits. However, the pulp colour was predominantly controlled by additive gene action. This implies the possibility of improving cassava through conventional breeding using recurrent selection for most traits. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Genome-Wide Analysis of the GRF Family Reveals Their Involvement in Abiotic Stress Response in Cassava.

    PubMed

    Shang, Sang; Wu, Chunlai; Huang, Chao; Tie, Weiwei; Yan, Yan; Ding, Zehong; Xia, Zhiqiang; Wang, Wenquan; Peng, Ming; Tian, Libo; Hu, Wei

    2018-02-20

    GENERAL REGULATORY FACTOR (GRF) proteins play vital roles in the regulation of plant growth, development, and response to abiotic stress. However, little information is known for this gene family in cassava ( Manihot esculenta ). In this study, 15 MeGRFs were identified from the cassava genome and were clustered into the ε and the non-ε groups according to phylogenetic, conserved motif, and gene structure analyses. Transcriptomic analyses showed eleven Me GRFs with constitutively high expression in stems, leaves, and storage roots of two cassava genotypes. Expression analyses revealed that the majority of GRFs showed transcriptional changes under cold, osmotic, salt, abscisic acid (ABA), and H₂O₂ treatments. Six Me GRFs were found to be commonly upregulated by abiotic stress, ABA, and H₂O₂ treatments, which may be the converging points of multiple signaling pathways. Interaction network analysis identified 18 possible interactors of MeGRFs. Taken together, this study elucidates the transcriptional control of Me GRFs in tissue development and the responses of abiotic stress and related signaling in cassava. Some constitutively expressed, tissue-specific, and abiotic stress-responsive candidate MeGRF genes were identified for the further genetic improvement of crops.

  9. Field Level RNAi-Mediated Resistance to Cassava Brown Streak Disease across Multiple Cropping Cycles and Diverse East African Agro-Ecological Locations

    PubMed Central

    Wagaba, Henry; Beyene, Getu; Aleu, Jude; Odipio, John; Okao-Okuja, Geoffrey; Chauhan, Raj Deepika; Munga, Theresia; Obiero, Hannington; Halsey, Mark E.; Ilyas, Muhammad; Raymond, Peter; Bua, Anton; Taylor, Nigel J.; Miano, Douglas; Alicai, Titus

    2017-01-01

    Cassava brown streak disease (CBSD) presents a serious threat to cassava production in East and Central Africa. Currently, no cultivars with high levels of resistance to CBSD are available to farmers. Transgenic RNAi technology was employed to combat CBSD by fusing coat protein (CP) sequences from Ugandan cassava brown streak virus (UCBSV) and Cassava brown streak virus (CBSV) to create an inverted repeat construct (p5001) driven by the constitutive Cassava vein mosaic virus promoter. Twenty-five plant lines of cultivar TME 204 expressing varying levels of small interfering RNAs (siRNAs) were established in confined field trials (CFTs) in Uganda and Kenya. Within an initial CFT at Namulonge, Uganda, non-transgenic TME 204 plants developed foliar and storage root CBSD incidences at 96–100% by 12 months after planting. In contrast, 16 of the 25 p5001 transgenic lines showed no foliar symptoms and had less than 8% of their storage roots symptomatic for CBSD. A direct positive correlation was seen between levels of resistance to CBSD and expression of transgenic CP-derived siRNAs. A subsequent CFT was established at Namulonge using stem cuttings from the initial trial. All transgenic lines established remained asymptomatic for CBSD, while 98% of the non-transgenic TME 204 stake-derived plants developed storage roots symptomatic for CBSD. Similarly, very high levels of resistance to CBSD were demonstrated by TME 204 p5001 RNAi lines grown within a CFT over a full cropping cycle at Mtwapa, coastal Kenya. Sequence analysis of CBSD causal viruses present at the trial sites showed that the transgenic lines were exposed to both CBSV and UCBSV, and that the sequenced isolates shared >90% CP identity with transgenic CP sequences expressed by the p5001 inverted repeat expression cassette. These results demonstrate very high levels of field resistance to CBSD conferred by the p5001 RNAi construct at diverse agro-ecological locations, and across the vegetative cropping cycle

  10. Consumer’s market analysis of products based on cassava

    NASA Astrophysics Data System (ADS)

    Unteawati, Bina; Fitriani; Fatih, Cholid

    2018-03-01

    Cassava product has the important role for enhancing household's income in rural. Cassava as raw material food is plentiful as local food in Lampung. Cassava product is one of strategic value addition activities. Value additional activities are a key to create income source enrichment in rural. The household was product cassava as a snack or additional food. Their product cassava was operated in small-scale, traditional, and discontinuous production. They have been lacked in technology, capital, and market access. Measurement the sustainability of their business is important. The market has driven the business globally. This research aims to (1) describe the cassava demand to locally product cassava in rural and (2) analysis the consumer's perception of cassava product. Research take placed in Lampung Province, involved Bandar Lampung and Metro City, Pringsewu, Pesawaran, Central Lampung, and East Lampung district. It is held in February until April 2017. Data were analyzed by descriptive statistic and multidimensional scaling. Based on the analysis conclude that (1) the demand of product cassava from rural was massive in volume and regularity with the enormous transaction. This fact is very important to role business cycles. Consumers demand continuously will lead the production of cassava product sustain. Producers of product cassava will consume fresh cassava for the farmer. Consumption of fresh cassava for home industry regularly in rural will develop balancing in fresh cassava price in the farming gate (2) The consumer's perception on cassava product in the different market showed that they prefer much to consume cassava chips as cassava product products than other. Next are crackers, opak, and tiwul rice. Urban consumers prefer product products as snacks (chips, crumbs, and opak), with consumption frequency of 2-5 times per week and volume of 1-3 kg purchases. Consumers in rural were more frequent with daily consumption frequency. Multidimensional scaling

  11. Comparison of Leaf Proteomes of Cassava (Manihot esculenta Crantz) Cultivar NZ199 Diploid and Autotetraploid Genotypes

    PubMed Central

    An, Feifei; Fan, Jie; Li, Jun; Li, Qing X.; Li, Kaimian; Zhu, Wenli; Wen, Feng; Carvalho, Luiz J. C. B.; Chen, Songbi

    2014-01-01

    Cassava polyploid breeding has drastically improved our knowledge on increasing root yield and its significant tolerance to stresses. In polyploid cassava plants, increases in DNA content highly affect cell volumes and anatomical structures. However, the mechanism of this effect is poorly understood. The purpose of the present study was to compare and validate the changes between cassava cultivar NZ199 diploid and autotetraploid at proteomic levels. The results showed that leaf proteome of cassava cultivar NZ199 diploid was clearly differentiated from its autotetraploid genotype using 2-DE combined MS technique. Sixty-five differential protein spots were seen in 2-DE image of autotetraploid genotype in comparison with that of diploid. Fifty-two proteins were identified by MALDI-TOF-MS/MS, of which 47 were up-regulated and 5 were down-regulated in autotetraploid genotype compared with diploid genotype. The classified functions of 32 up-regulated proteins were associated with photosynthesis, defense system, hydrocyanic acid (HCN) metabolism, protein biosynthesis, chaperones, amino acid metabolism and signal transduction. The remarkable variation in photosynthetic activity, HCN content and resistance to salt stress between diploid and autotetraploid genotypes is closely linked with expression levels of proteomic profiles. The analysis of protein interaction networks indicated there are direct interactions between the 15 up-regulation proteins involved in the pathways described above. This work provides an insight into understanding the protein regulation mechanism of cassava polyploid genotype, and gives a clue to improve cassava polyploidy breeding in increasing photosynthesis and resistance efficiencies. PMID:24727655

  12. Biological suppression of potato ring rot by fluorescent pseudomonads.

    PubMed Central

    de la Cruz, A R; Poplawsky, A R; Wiese, M V

    1992-01-01

    Three strains of fluorescent pseudomonads (IS-1, IS-2, and IS-3) isolated from potato underground stems with roots showed in vitro antibiosis against 30 strains of the ring rot bacterium Clavibacter michiganensis subsp. sepedonicus. On the basis of morphological and biochemical tests and fatty acid analysis, IS-1 and IS-2 were identified as Pseudomonas aureofaciens and IS-3 was identified as P. fluorescens biovar III. IS-1 was the most inhibitory to C. michiganensis subsp. sepedonicus strains in vitro, followed by IS-3 and IS-2. Suppression of ring rot by these antagonists was demonstrated in greenhouse trials with stem-cultured potato (cv. Russet Burbank) seedlings. Although each antagonist significantly reduced C. michiganensis subsp. sepedonicus populations, only IS-1 reduced infection by C. michiganensis subsp. sepedonicus. In a second experiment, treatment with IS-1 (10(9) CFU/ml) significantly reduced ring rot infection by 23.4 to 26.7% after 5 to 8 weeks. The average C. michiganensis subsp. sepedonicus population was also significantly reduced by 50 to 52%. Application of different combinations of antagonist strains was not more effective than single-strain treatment. Images PMID:1622275

  13. Differential Responses of Vanilla Accessions to Root Rot and Colonization by Fusarium oxysporum f. sp. radicis-vanillae

    PubMed Central

    Koyyappurath, Sayuj; Conéjéro, Geneviève; Dijoux, Jean Bernard; Lapeyre-Montès, Fabienne; Jade, Katia; Chiroleu, Frédéric; Gatineau, Frédéric; Verdeil, Jean Luc; Besse, Pascale; Grisoni, Michel

    2015-01-01

    Root and stem rot (RSR) disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv) is the most damaging disease of vanilla (Vanilla planifolia and V. × tahitensis, Orchidaceae). Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have (i) identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, (ii) thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and (iii) evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions. Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in vitro assay. The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21 accessions

  14. Differential Responses of Vanilla Accessions to Root Rot and Colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    PubMed

    Koyyappurath, Sayuj; Conéjéro, Geneviève; Dijoux, Jean Bernard; Lapeyre-Montès, Fabienne; Jade, Katia; Chiroleu, Frédéric; Gatineau, Frédéric; Verdeil, Jean Luc; Besse, Pascale; Grisoni, Michel

    2015-01-01

    Root and stem rot (RSR) disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv) is the most damaging disease of vanilla (Vanilla planifolia and V. × tahitensis, Orchidaceae). Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have (i) identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, (ii) thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and (iii) evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions. Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in vitro assay. The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21 accessions

  15. Biology, diagnosis and management of Heterobasidion Root Disease of southern pines

    Treesearch

    Tyler J. Dreaden; Jason A.  Smith; Michelle M. Cram; David R   Coyle

    2016-01-01

    Heterobasidion root disease (previously called annosum, annosus, or Fomes root disease / root rot) is one of the most economically damaging forest diseases in the Northern Hemisphere. Heterobasidion root disease (HRD) in the southeastern U.S. is caused by the pathogen Heterobasidion irregulare, which infects loblolly, longleaf, pitch, shortleaf, slash, Virginia, and...

  16. Divergent Regulation of CBF Regulon on Cold Tolerance and Plant Phenotype in Cassava Overexpressing Arabidopsis CBF3 Gene.

    PubMed

    An, Dong; Ma, Qiuxiang; Yan, Wei; Zhou, Wenzhi; Liu, Guanghua; Zhang, Peng

    2016-01-01

    Cassava is a tropical origin plant that is sensitive to chilling stress. In order to understand the CBF cold response pathway, a well-recognized regulatory mechanism in temperate plants, in cassava, overexpression of an Arabidopsis CBF3 gene is studied. This gene renders cassava increasingly tolerant to cold and drought stresses but is associated with retarded plant growth, leaf curling, reduced storage root yield, and reduced anthocyanin accumulation in a transcript abundance-dependent manner. Physiological analysis revealed that the transgenic cassava increased proline accumulation, reduced malondialdehyde production, and electrolyte leakage under cold stress. These transgenic lines also showed high relative water content when faced with drought. The expression of partial CBF-targeted genes in response to cold displayed temporal and spatial variations in the wild-type and transgenic plants: highly inducible in leaves and less altered in apical buds. In addition, anthocyanin accumulation was inhibited by downregulating the expression of genes involved in its biosynthesis and by interplaying between the CBF3 and the endogenous transcription factors. Thus, the heterologous CBF3 modulates the expression of stress-related genes and carries out a series of physiological adjustments under stressful conditions, showing a varied regulation pattern of CBF regulon from that of cassava CBFs.

  17. Effects of feeding fresh cassava root with high-sulfur feed block on feed utilization, rumen fermentation, and blood metabolites in Thai native cattle.

    PubMed

    Cherdthong, Anusorn; Khonkhaeng, Benjamad; Seankamsorn, Anuthida; Supapong, Chanadol; Wanapat, Metha; Gunun, Nirawan; Gunun, Pongsatron; Chanjula, Pin; Polyorach, Sineenart

    2018-03-14

    The objective of this research was to evaluate the effect of feeding fresh cassava root (CR) along with a feed block containing high was to sulfur (FBS) on feed intake, digestibility, rumen fermentation, and blood thiocyanate concentration in Thai native beef cattle. Four Thai male native beef cattle, initial body weight (BW) of 130 + 20.0 kg, were used in this study. The experiments were randomly assigned according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. The main factors were supplemented fresh CR levels (1.0 and 1.5% BW) and across to a feed block supplemented with sulfur added 2% (FBS-2) and 4% (FBS-4). Intakes of rice straw, concentrate diets, and FBS were not affected by treatments. Intakes of CR, sulfur, and total intake were significantly altered by the FBS treatment. The apparent dry matter and organic matter digestibility coefficient were significantly higher in animals fed FBS-4 than in those fed FBS-2. The ruminal ammonia nitrogen concentration was not affected by treatment and ranged from 15.6 to 17.6 mg/dl. Populations of protozoa and fungal zoospores were similar across treatments, whereas the bacterial population was significantly different between sulfur levels in the feed block. Feeding CR with FBS did not change total volatile fatty acid (VFA) concentrations and VFA profiles except for the propionic acid concentration, which was higher in the group with CR supplementation at 1.5% BW. Cattle fed CR with FBS showed similar blood urea nitrogen concentration at various feeding times and overall. In contrast, CR supplementation at 1.5% BW with FBS-2 increased blood thiocyanate concentrations. Therefore, supplementation of FBS-2 was beneficial to Thai native beef cattle fed with 1.5% BW fresh CR as it improved digestibility and rumen fermentation presumed, because HCN from fresh cassava root was converted into thiocyanate, which is nontoxic to farm animals.

  18. A Virus-Derived Stacked RNAi Construct Confers Robust Resistance to Cassava Brown Streak Disease

    PubMed Central

    Beyene, Getu; Chauhan, Raj Deepika; Ilyas, Muhammad; Wagaba, Henry; Fauquet, Claude M.; Miano, Douglas; Alicai, Titus; Taylor, Nigel J.

    2017-01-01

    Cassava brown streak disease (CBSD) threatens food and economic security for smallholder farmers throughout East and Central Africa, and poses a threat to cassava production in West Africa. CBSD is caused by two whitefly-transmitted virus species: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) (Genus: Ipomovirus, Family Potyviridae). Although varying levels of tolerance have been achieved through conventional breeding, to date, effective resistance to CBSD within East African cassava germplasm has not been identified. RNAi technology was utilized to integrate CBSD resistance into the Ugandan farmer-preferred cassava cultivar TME 204. Transgenic plant lines were generated expressing an inverted repeat construct (p5001) derived from coat-protein (CP) sequences of CBSV and UCBSV fused in tandem. Northern blots using probes specific for each CP sequence were performed to characterize 169 independent transgenic lines for accumulation of CP-derived siRNAs. Transgenic plant lines accumulating low, medium and high levels of siRNAs were bud graft challenged with the virulent CBSV Naliendele isolate alone or in combination with UCBSV. Resistance to CBSD in the greenhouse directly correlated to levels of CP-derived siRNAs as determined by visual assessment of leaf and storage root symptoms, and RT-PCR diagnosis for presence of the pathogens. Low expressing lines were found to be susceptible to CBSV and UCBSV, while medium to high accumulating plant lines were resistant to both virus species. Absence of detectable virus in the best performing p5001 transgenic lines was further confirmed by back-inoculation via sap or graft challenge to CBSD susceptible Nicotiana benthamiana and cassava cultivar 60444, respectively. Data presented shows robust resistance of transgenic p5001 TME 204 lines to both CBSV and UCBSV under greenhouse conditions. Levels of resistance correlated directly with levels of transgene derived siRNA expression such that the

  19. The Effect of Fungicides on Mycelial Growth and Conidial Germination of the Ginseng Root Rot Fungus, Cylindrocarpon destructans

    PubMed Central

    Shin, Jong-Hwan; Fu, Teng; Park, Kyeong Hun

    2017-01-01

    Ginseng root rot caused by Cylindrocarpon destructans is the most destructive disease of ginseng. Six different fungicides (thiophanate-methyl, benomyl, prochloraz, mancozeb, azoxystrobin, and iprodione) were selected to evaluate the inhibitory effect on the mycelial growth and conidial germination of C. destructans isolates. Benomyl and prochloraz were found to be the most effective fungicides in inhibiting mycelial growth of all tested isolates, showing 64.7% to 100% inhibition at a concentration of 10 µg/mL, whereas thiophanate-methyl was the least effective fungicide, showing less than 50% inhibition even at a higher concentration of 100 µg/mL. The tested fungicides exhibited less than 20% inhibition of conidium germination at concentrations of 0.01, 0.1, and 1 µg/mL. However, the inhibition effect of mancozeb on condium germination of C. destructans was significantly increased to 92% to 99% at a higher concentration of 100 µg/mL, while the others still showed no higher than 30% inhibition. PMID:29138629

  20. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

    PubMed

    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-07-06

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

  1. Improvement in the traditional processing method and nutritional quality of traditional extruded cassava-based snack (modified Ajogun).

    PubMed

    Obadina, Adewale O; Oyewole, Olusola B; Williams, Oluwasolabomi E

    2013-07-01

    This study was carried out to investigate and improve the traditional processing method and nutritional quality of the traditional cassava snack (Ajogun). Cassava root (Manihot esculenta Crantz L.) of TME 419 variety was processed into mash (40% moisture content). The cassava mash was mixed into different blends to produce fried traditional "Ajogun", fried and baked extrudates (modified Ajogun) as snacks. These products were analyzed to determine the proximate composition including carbohydrate, fat, protein, fiber, ash, and moisture contents and functional properties such as bulk density. The results obtained for the moisture, fat, protein, and ash contents showed significant difference (P < 0.05) between the control sample and the extrudates. However, there was no significant difference (P > 0.05) in the carbohydrate and fiber contents between the three samples. There was no significant difference (P > 0.05) in the bulk density of the snacks. Also, sensory evaluation was carried out on the cassava-based snacks using the 9-point hedonic scale to determine the degree of acceptability. Results obtained showed significant difference (P < 0.05) between the extrudates and control sample in terms of appearance, taste, flavor, color, aroma, texture, and overall acceptability. The highest acceptability level of the product was at 8.04 for the control sample (traditional Ajogun). This study has shown that "Ajogun", which is a lesser known cassava product, is rich in protein and fat.

  2. Co-Inoculation with Rhizobia and AMF Inhibited Soybean Red Crown Rot: From Field Study to Plant Defense-Related Gene Expression Analysis

    PubMed Central

    Gao, Xiang; Lu, Xing; Wu, Man; Zhang, Haiyan; Pan, Ruqian; Tian, Jiang; Li, Shuxian; Liao, Hong

    2012-01-01

    Background Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases. Principal Findings We firstly investigated the disease incidence and index of soybean red crown rot under different phosphorus (P) additions in field and found that the natural inoculation of rhizobia and arbuscular mycorrhizal fungi (AMF) could affect soybean red crown rot, particularly without P addition. Further studies in sand culture experiments showed that inoculation with rhizobia or AMF significantly decreased severity and incidence of soybean red crown rot, especially for co-inoculation with rhizobia and AMF at low P. The root colony forming unit (CFU) decreased over 50% when inoculated by rhizobia and/or AMF at low P. However, P addition only enhanced CFU when inoculated with AMF. Furthermore, root exudates of soybean inoculated with rhizobia and/or AMF significantly inhibited pathogen growth and reproduction. Quantitative RT-PCR results indicated that the transcripts of the most tested pathogen defense-related (PR) genes in roots were significantly increased by rhizobium and/or AMF inoculation. Among them, PR2, PR3, PR4 and PR10 reached the highest level with co-inoculation of rhizobium and AMF. Conclusions Our results indicated that inoculation with rhizobia and AMF could directly inhibit pathogen growth and reproduction, and activate the plant overall defense system through increasing PR gene expressions. Combined with optimal P fertilization, inoculation with rhizobia and AMF could be considered as an efficient method to control soybean red crown rot in acid soils. PMID:22442737

  3. Development of formulations of biological agents for management of root rot of lettuce and cucumber.

    PubMed

    Amer, G A; Utkhede, R S

    2000-09-01

    The effect of various carrier formulations of Bacillus subtilis and Pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of Pythium aphanidermatum and Fusarium oxysporum f.sp. cucurbitacearum, respectively. Survival of B. subtilis and P. putida in various carriers under refrigeration (about 0 degree C) and at room temperature (about 22 degrees C) was also studied. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days. After 45 days of storage at room temperature (about 22 degrees C), populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers. Populations of P. putida were significantly higher in vermiculite, peat moss, wheat bran, and bacterial broth than in other carriers when stored either under refrigeration (about 0 degree C) or at room temperature (about 22 degrees C) for 15 or 45 days. Germination of lettuce seed was not affected in vermiculite, talc, kaolin, and peat moss carriers, but germination was significantly reduced in alginate and bacterial broth carriers of B. subtilis compared to the non-treated control. Germination of cucumber seed was not affected by any of the carriers. Significantly higher fresh lettuce and root weights were observed in vermiculite and kaolin carriers of B. subtilis compared with P. aphanidermatum-inoculated control plants. Lettuce treated with vermiculite, and kaolin carriers of B. subtilis, or non-inoculated control lettuce plants had significantly lower root rot ratings than talc, peat moss, bacterial broth, and P. aphanidermatum-inoculated control plants. Growth and yield of cucumber plants were significantly higher in vermiculite-based carrier of P. putida than the other carriers and Fusarium oxysporum f.sp. cucurbitacearum-inoculated plants.

  4. Pathogenicity of some Rhizoctonia solaniz isolates associated with root/collar rots on the cultivars of bean in greenhouse.

    PubMed

    Bohlooli, A; Okhovvat, S M; Javan-Nikkhah, M

    2006-01-01

    One hundred and eighteen isolates of Rhizoctonia solani were gathered from infected roots and hypocotyls of bean (Phaseolus vulgaris L.) grown in the fields of Tehran Province, Iran. Two isolates of the collected samples belonged to binucleate and 81 isolates to multinucleate of R. solani. The multinucleate isolates showed different anastomosis groups as AG-4 (subg. AG-4 HGI, AG-4HGII), AG-6 and AG-2. In greenhouse, pathogenicity tests carried out on bean cv. Naz in randomized design with 4 replications and each replication (pots) with 5 seeds of bean. Infection was done with seeds of wheat which were infected to the fungus with pasteurized soil. Results showed that the highest disease severity was caused by AG-4 (Rs21) isolates, whereas AG-4 (Rs74) isolates were weakly pathogenic with 90% and 21% infection, respectively. In this test the major pathogenic isolates belonged to AG-4 and they caused seed rot and damping-off of bean and AG-6 isolates were non-pathogenic. Five isolates of the fungus with major pathogenicity (Rs7, Rs18, Rs21, Rs62 and Rs71) selected and used for the reaction with different cultivars of bean. In this test, the cultivars and lines of bean (Pinto, red, white, green) studied in factorial experiment as randomized block design with 4 replications (pots). Results showed that none of the cultivars was completely resistant, however green bean cv. Sanry and pinto cv. Shad with number 4.8 disease severities had the highest susceptibility to seed rot and damping-off and red bean cv. Goli with 2.58 had the lowest susceptibility to the infection. Reaction of the cultivars and lines to the isolates of R. solani was significantly different at 1% level. Isolates of the fungus, Rs7, Rs21 with 84%, 90% pathogenicity was more virulent than the others.

  5. Biocontrol of Fusarium Crown and Root Rot and Promotion of Growth of Tomato by Paenibacillus Strains Isolated from Soil

    PubMed Central

    Xu, Sheng Jun

    2014-01-01

    In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant. PMID:25071385

  6. Cassava as an energy source: a selected bibliography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sherman, C.

    1980-01-01

    This selected bibliography includes 250 articles on cassava as a potential energy source. Factors included are things which influence cassava growth; such as weeding, fertilizer, diseases and genetic selection, as well as the conversion of cassava to ethanol. (DP)

  7. Improvement in the traditional processing method and nutritional quality of traditional extruded cassava-based snack (modified Ajogun)

    PubMed Central

    Obadina, Adewale O; Oyewole, Olusola B; Williams, Oluwasolabomi E

    2013-01-01

    This study was carried out to investigate and improve the traditional processing method and nutritional quality of the traditional cassava snack (Ajogun). Cassava root (Manihot esculenta Crantz L.) of TME 419 variety was processed into mash (40% moisture content). The cassava mash was mixed into different blends to produce fried traditional “Ajogun”, fried and baked extrudates (modified Ajogun) as snacks. These products were analyzed to determine the proximate composition including carbohydrate, fat, protein, fiber, ash, and moisture contents and functional properties such as bulk density. The results obtained for the moisture, fat, protein, and ash contents showed significant difference (P < 0.05) between the control sample and the extrudates. However, there was no significant difference (P > 0.05) in the carbohydrate and fiber contents between the three samples. There was no significant difference (P > 0.05) in the bulk density of the snacks. Also, sensory evaluation was carried out on the cassava-based snacks using the 9-point hedonic scale to determine the degree of acceptability. Results obtained showed significant difference (P < 0.05) between the extrudates and control sample in terms of appearance, taste, flavor, color, aroma, texture, and overall acceptability. The highest acceptability level of the product was at 8.04 for the control sample (traditional Ajogun). This study has shown that “Ajogun”, which is a lesser known cassava product, is rich in protein and fat. PMID:24804039

  8. Identification and functional analysis of cassava DELLA proteins in plant disease resistance against cassava bacterial blight.

    PubMed

    Li, Xiaolin; Liu, Wen; Li, Bing; Liu, Guoyin; Wei, Yunxie; He, Chaozu; Shi, Haitao

    2018-03-01

    Gibberellin (GA) is an essential plant hormone in plant growth and development as well as various stress responses. DELLA proteins are important repressors of GA signal pathway. GA and DELLA have been extensively investigated in several model plants. However, the in vivo roles of GA and DELLA in cassava, one of the most important crops and energy crops in the tropical area, are unknown. In this study, systematic genome-wide analysis identified 4 MeDELLAs in cassava, as evidenced by the evolutionary tree, gene structures and motifs analyses. Gene expression analysis found that 4 MeDELLAs were commonly regulated by flg22 and Xanthomonas axonopodis pv manihotis (Xam). Through overexpression in Nicotiana benthamiana, we found that 4 MeDELLAs conferred improved disease resistance against cassava bacterial blight. Through virus-induced gene silencing (VIGS) in cassava, we found that MeDELLA-silenced plants exhibited decreased disease resistance, with less callose deposition and lower transcript levels of defense-related genes. This is the first study identifying MeDELLAs as positive regulators of disease resistance against cassava bacterial blight. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Unveiling the Micronome of Cassava (Manihot esculenta Crantz)

    PubMed Central

    2016-01-01

    MicroRNAs (miRNAs) are an important class of endogenous non-coding single-stranded small RNAs (21–24 nt in length), which serve as post-transcriptional negative regulators of gene expression in plants. Despite the economic importance of Manihot esculenta Crantz (cassava) only 153 putative cassava miRNAs (from multiple germplasm) are available to date in miRBase (Version 21), and identification of a number of miRNAs from the cassava EST database have been limited to comparisons with Arabidopsis. In this study, mature sequences of all known plant miRNAs were used as a query for homologous searches against cassava EST and GSS databases, and additional identification of novel and conserved miRNAs were gleaned from next generation sequencing (NGS) of two cassava landraces (T200 from southern Africa and TME3 from West Africa) at three different stages post explant transplantation and acclimatization. EST and GSS derived data revealed 259 and 32 miRNAs in cassava, and one of the miRNA families (miR2118) from previous studies has not been reported in cassava. NGS data collectively displayed expression of 289 conserved miRNAs in leaf tissue, of which 230 had not been reported previously. Of the 289 conserved miRNAs identified in T200 and TME3, 208 were isomiRs. Thirty-nine novel cassava-specific miRNAs of low abundance, belonging to 29 families, were identified. Thirty-eight (98.6%) of the putative new miRNAs identified by NGS have not been previously reported in cassava. Several miRNA targets were identified in T200 and TME3, highlighting differential temporal miRNA expression between the two cassava landraces. This study contributes to the expanding knowledge base of the micronome of this important crop. PMID:26799216

  10. Potential functions of microRNAs in starch metabolism and development revealed by miRNA transcriptome profiling of cassava cultivars and their wild progenitor.

    PubMed

    Chen, Xin; Xia, Jing; Xia, Zhiqiang; Zhang, Hefang; Zeng, Changying; Lu, Cheng; Zhang, Weixiong; Wang, Wenquan

    2015-02-04

    MicroRNAs (miRNAs) are small (approximately 21 nucleotide) non-coding RNAs that are key post-transcriptional gene regulators in eukaryotic organisms. More than 100 cassava miRNAs have been identified in a conservation analysis and a repertoire of cassava miRNAs have also been characterised by next-generation sequencing (NGS) in recent studies. Here, using NGS, we profiled small non-coding RNAs and mRNA genes in two cassava cultivars and their wild progenitor to identify and characterise miRNAs that are potentially involved in plant growth and starch biosynthesis. Six small RNA and six mRNA libraries from leaves and roots of the two cultivars, KU50 and Arg7, and their wild progenitor, W14, were subjected to NGS. Analysis of the sequencing data revealed 29 conserved miRNA families and 33 new miRNA families. Together, these miRNAs potentially targeted a total of 360 putative target genes. Whereas 16 miRNA families were highly expressed in cultivar leaves, another 13 miRNA families were highly expressed in storage roots of cultivars. Co-expression analysis revealed that the expression level of some targets had negative relationship with their corresponding miRNAs in storage roots and leaves; these targets included MYB33, ARF10, GRF1, RD19, APL2, NF-YA3 and SPL2, which are known to be involved in plant development, starch biosynthesis and response to environmental stimuli. The identified miRNAs, target mRNAs and target gene ontology annotation all shed light on the possible functions of miRNAs in Manihot species. The differential expression of miRNAs between cultivars and their wild progenitor, together with our analysis of GO annotation and confirmation of miRNA: target pairs, might provide insight into know the differences between wild progenitor and cultivated cassava.

  11. The Late Embryogenesis Abundant Protein Family in Cassava (Manihot esculenta Crantz): Genome-Wide Characterization and Expression during Abiotic Stress.

    PubMed

    Wu, Chunlai; Hu, Wei; Yan, Yan; Tie, Weiwei; Ding, Zehong; Guo, Jianchun; He, Guangyuan

    2018-05-17

    Late embryogenesis abundant (LEA) proteins, as a highly diverse group of polypeptides, play an important role in plant adaptation to abiotic stress; however, LEAs from cassava have not been studied in cassava. In this study, 26 LEA members were genome-wide identified from cassava, which were clustered into seven subfamily according to evolutionary relationship, protein motif, and gene structure analyses. Chromosomal location and duplication event analyses suggested that 26 MeLEAs distributed in 10 chromosomes and 11 MeLEA paralogues were subjected to purifying selection. Transcriptomic analysis showed the expression profiles of MeLEAs in different tissues of stem, leaves, and storage roots of three accessions. Comparative transcriptomic analysis revealed that the function of MeLEAs in response to drought may be differentiated in different accessions. Compared with the wild subspecies W14, more MeLEA genes were activated in cultivated varieties Arg7 and SC124 after drought treatment. Several MeLEA genes showed induction under various stresses and related signaling treatments. Taken together, this study demonstrates the transcriptional control of MeLEAs in tissue development and the responses to abiotic stress in cassava and identifies candidate genes for improving crop resistance to abiotic stress.

  12. Assessment of cassava toxicity in patients with tropical chronic pancreatitis.

    PubMed

    Girish, Banavara Narasimhamurthy; Rajesh, Gopalakrishna; Vaidyanathan, Kannan; Balakrishnan, Vallath

    2011-01-01

    There have been conflicting reports on the role of cassava ingestion in tropical pancreatitis (TCP). In this study we aimed to estimate cyanogens detoxifying enzyme rhodanese, thiocyanate and sulfur containing amino acids in cassava consumer as well as cassava non-consumer TCP patients and healthy controls and compare the same. Eighty-six TCP patients and 90 healthy controls were recruited. Serum rhodanese, thiocyanate, plasma amino acids, urinary inorganic sulfate/creatinine were measured. There was significant reduction in serum rhodanese activity in both cassava consumer- and non-consumer TCP patients as compared to controls but no significant difference between cassava consumer- and non-consumer TCP patients was observed. Serum thiocyanate was significantly lower in cassava consumer TCP patients as compared to cassava consumer controls but not significantly different from cassava non-consumer TCP patients. Plasma methionine, cysteine and urinary inorganic sulfate / creatinine ratio was significantly lower in both cassava consumer and non-consumer TCP patients as compared to controls but were comparable among cassava consumers and non-consumers. Significant reduction in rhodanese activity with concomitant decrease in sulfur containing amino acids and antioxidants such as glutathione suggests that TCP patients are at higher risk of defective detoxification of cyanogens. However there was no difference between cassava consumers and non-consumers. Low levels of sulfur amino acids may contribute to the development of pancreatitis.

  13. Energy balance associated with the degradation of lignocellulosic material by white-rot and brown-rot fungi.

    NASA Astrophysics Data System (ADS)

    Derrien, Delphine; Bédu, Hélène; Buée, Marc; Kohler, Annegret; Goodell, Barry; Gelhaye, Eric

    2017-04-01

    Forest soils cover about 30% of terrestrial area and comprise between 50 and 80% of the global stock of soil organic carbon (SOC). The major precursor for this forest SOC is lignocellulosic material, which is made of polysaccharides and lignin. Lignin has traditionally been considered as a recalcitrant polymer that hinders access to the much more labile structural polysaccharides. This view appears to be partly incorrect from a microbiology perspective yet, as substrate alteration depends on the metabolic potential of decomposers. In forest ecosystems the wood-rotting Basidiomycota fungi have developed two different strategies to attack the structure of lignin and gain access to structural polysaccharides. White-rot fungi degrade all components of plant cell walls, including lignin, using enzymatic systems. Brown-rot fungi do not remove lignin. They generate oxygen-derived free radicals, such as the hydroxyl radical produced by the Fenton reaction, that disrupt the lignin polymer and depolymerize polysaccharides which then diffuse out to where the enzymes are located The objective of this study was to develop a model to investigate whether the lignin relative persistence could be related to the energetic advantage of brown-rot degradative pathway in comparison to white-rot degradative pathway. The model simulates the changes in substrate composition over time, and determines the energy gained from the conversion of the lost substrate into CO2. The energy cost for the production of enzymes involved in substrate alteration is assessed using information derived from genome and secretome analysis. For brown-rot fungus specifically, the energy cost related to the production of OH radicals is also included. The model was run, using data from the literature on populous wood degradation by Trametes versicolor, a white-rot fungus, and Gloeophyllum trabeum, a brown-rot fungus. It demonstrates that the brown-rot fungus (Gloeophyllum trabeum) was more efficient than the white-rot

  14. The industrial applications of cassava: current status, opportunities and prospects.

    PubMed

    Li, Shubo; Cui, Yanyan; Zhou, Yuan; Luo, Zhiting; Liu, Jidong; Zhao, Mouming

    2017-06-01

    Cassava (Manihot esculenta Crantz) is a drought-tolerant, staple food crop that is grown in tropical and subtropical areas. As an important raw material, cassava is a valuable food source in developing countries and is also extensively employed for producing starch, bioethanol and other bio-based products (e.g. feed, medicine, cosmetics and biopolymers). These cassava-based industries also generate large quantities of wastes/residues rich in organic matter and suspended solids, providing great potential for conversion into value-added products through biorefinery. However, the community of cassava researchers is relatively small and there is very limited information on cassava. Therefore this review summarizes current knowledge on the system biology, economic value, nutritional quality and industrial applications of cassava and its wastes in an attempt to accelerate understanding of the basic biology of cassava. The review also discusses future perspectives with respect to integrating and utilizing cassava information resources for increasing the economic and environmental sustainability of cassava industries. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. High-throughput sequencing of black pepper root transcriptome.

    PubMed

    Gordo, Sheila M C; Pinheiro, Daniel G; Moreira, Edith C O; Rodrigues, Simone M; Poltronieri, Marli C; de Lemos, Oriel F; da Silva, Israel Tojal; Ramos, Rommel T J; Silva, Artur; Schneider, Horacio; Silva, Wilson A; Sampaio, Iracilda; Darnet, Sylvain

    2012-09-17

    Black pepper (Piper nigrum L.) is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host's root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant's root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms.

  16. Time-resolved dual transcriptomics reveal early induced Nicotiana benthamiana root genes and conserved infection-promoting Phytophthora palmivora effectors.

    PubMed

    Evangelisti, Edouard; Gogleva, Anna; Hainaux, Thomas; Doumane, Mehdi; Tulin, Frej; Quan, Clément; Yunusov, Temur; Floch, Kévin; Schornack, Sebastian

    2017-05-11

    Plant-pathogenic oomycetes are responsible for economically important losses in crops worldwide. Phytophthora palmivora, a tropical relative of the potato late blight pathogen, causes rotting diseases in many tropical crops including papaya, cocoa, oil palm, black pepper, rubber, coconut, durian, mango, cassava and citrus. Transcriptomics have helped to identify repertoires of host-translocated microbial effector proteins which counteract defenses and reprogram the host in support of infection. As such, these studies have helped in understanding how pathogens cause diseases. Despite the importance of P. palmivora diseases, genetic resources to allow for disease resistance breeding and identification of microbial effectors are scarce. We employed the model plant Nicotiana benthamiana to study the P. palmivora root infections at the cellular and molecular levels. Time-resolved dual transcriptomics revealed different pathogen and host transcriptome dynamics. De novo assembly of P. palmivora transcriptome and semi-automated prediction and annotation of the secretome enabled robust identification of conserved infection-promoting effectors. We show that one of them, REX3, suppresses plant secretion processes. In a survey for early transcriptionally activated plant genes we identified a N. benthamiana gene specifically induced at infected root tips that encodes a peptide with danger-associated molecular features. These results constitute a major advance in our understanding of P. palmivora diseases and establish extensive resources for P. palmivora pathogenomics, effector-aided resistance breeding and the generation of induced resistance to Phytophthora root infections. Furthermore, our approach to find infection-relevant secreted genes is transferable to other pathogen-host interactions and not restricted to plants.

  17. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi

    PubMed Central

    Riley, Robert; Salamov, Asaf A.; Brown, Daren W.; Nagy, Laszlo G.; Floudas, Dimitrios; Held, Benjamin W.; Levasseur, Anthony; Lombard, Vincent; Morin, Emmanuelle; Otillar, Robert; Lindquist, Erika A.; Sun, Hui; LaButti, Kurt M.; Schmutz, Jeremy; Jabbour, Dina; Luo, Hong; Baker, Scott E.; Pisabarro, Antonio G.; Walton, Jonathan D.; Blanchette, Robert A.; Henrissat, Bernard; Martin, Francis; Cullen, Dan; Hibbett, David S.; Grigoriev, Igor V.

    2014-01-01

    Basidiomycota (basidiomycetes) make up 32% of the described fungi and include most wood-decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white-rot/brown-rot classification paradigm, we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically informed principal-components analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white-rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown-rot fungi. Our results suggest a continuum rather than a dichotomy between the white-rot and brown-rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay. PMID:24958869

  18. The development of spectro-signature indicators of root disease impacts on forest stands

    NASA Technical Reports Server (NTRS)

    Weber, F. P.; Wear, J. F.

    1970-01-01

    A field research program was begun in 1969 and intensified in 1970 on the physiology and biophysical responses of second-growth Douglas fir infected with root rot fungus. A double tramway system was suspended between three 100-foot instrument towers to carry sensors for measuring the energy response from above both healthy and infected trees. Processing and analysis was completed of airborne multispectral scanner imagery collected over the Wind River research area in 1969. Likelihood ratio processing of three-channel infrared data and Euclidean distance analysis of ten-channel spectrometer data did not identify incipient root rot infection outside the training sets. In all cases infected fir was misclassified as healthy fir. It was concluded from careful examination of physiological data that Poria root rot infection has little effect on water metabolism and energy exchange. What was identified was a low-grade stress that affects respiration and metabolism over long periods of time. This led to minor changes in the external physical symptoms of Poria-infected trees which was revealed only in the shortwave reflectance data.

  19. Antifungal Compound Isolated from Catharanthus roseus L. (Pink) for Biological Control of Root Rot Rubber Diseases.

    PubMed

    Zahari, R; Halimoon, N; Ahmad, M F; Ling, S K

    2018-01-01

    Rigidoporus microporus, Ganoderma philippii, and Phellinus noxius are root rot rubber diseases and these fungi should be kept under control with environmentally safe compounds from the plant sources. Thus, an antifungal compound isolated from Catharanthus roseus was screened for its effectiveness in controlling the growth of these fungi. The antifungal compound isolated from C. roseus extract was determined through thin layer chromatography (TLC) and nuclear magnetic resonance (NMR) analysis. Each C. roseus of the DCM extracts was marked as CRD1, CRD2, CRD3, CRD4, CRD5, CRD6, and CRD7, respectively. TLC results showed that all of the C. roseus extracts peaked with red colour at Rf = 0.61 at 366 nm wavelength, except for CRD7. The CRD4 extract was found to be the most effective against R. microporus and G. philippii with inhibition zones of 3.5 and 1.9 mm, respectively, compared to that of other extracts. These extracts, however, were not effective against P. noxius. The CRD4 extract contained ursolic acid that was detected by NMR analysis and the compound could be developed as a biocontrol agent for controlling R. microporus and G. philippii. Moreover, little or no research has been done to study the effectiveness of C. roseus in controlling these fungi.

  20. Genome-wide characterization and analysis of bZIP transcription factor gene family related to abiotic stress in cassava.

    PubMed

    Hu, Wei; Yang, Hubiao; Yan, Yan; Wei, Yunxie; Tie, Weiwei; Ding, Zehong; Zuo, Jiao; Peng, Ming; Li, Kaimian

    2016-03-07

    The basic leucine zipper (bZIP) transcription factor family plays crucial roles in various aspects of biological processes. Currently, no information is available regarding the bZIP family in the important tropical crop cassava. Herein, 77 bZIP genes were identified from cassava. Evolutionary analysis indicated that MebZIPs could be divided into 10 subfamilies, which was further supported by conserved motif and gene structure analyses. Global expression analysis suggested that MebZIPs showed similar or distinct expression patterns in different tissues between cultivated variety and wild subspecies. Transcriptome analysis of three cassava genotypes revealed that many MebZIP genes were activated by drought in the root of W14 subspecies, indicating the involvement of these genes in the strong resistance of cassava to drought. Expression analysis of selected MebZIP genes in response to osmotic, salt, cold, ABA, and H2O2 suggested that they might participate in distinct signaling pathways. Our systematic analysis of MebZIPs reveals constitutive, tissue-specific and abiotic stress-responsive candidate MebZIP genes for further functional characterization in planta, yields new insights into transcriptional regulation of MebZIP genes, and lays a foundation for understanding of bZIP-mediated abiotic stress response.

  1. Involvement of miR160/miR393 and their targets in cassava responses to anthracnose disease.

    PubMed

    Pinweha, Nattaya; Asvarak, Thipa; Viboonjun, Unchera; Narangajavana, Jarunya

    2015-02-01

    Cassava is a starchy root crop for food and industrial applications in many countries around the world. Among the factors that affect cassava production, diseases remain the major cause of yield loss. Cassava anthracnose disease is caused by the fungus Colletotrichum gloeosporioides. Severe anthracnose attacks can cause tip die-backs and stem cankers, which can affect the availability of planting materials especially in large-scale production systems. Recent studies indicate that plants over- or under-express certain microRNAs (miRNAs) to cope with various stresses. Understanding how a disease-resistant plant protects itself from pathogens should help to uncover the role of miRNAs in the plant immune system. In this study, the disease severity assay revealed different response to C. gloeosporioides infection in two cassava cultivars. Quantitative RT-PCR analysis uncovered the differential expression of the two miRNAs and their target genes in the two cassava cultivars that were subjected to fungal infection. The more resistant cultivar revealed the up-regulation of miR160 and miR393, and consequently led to low transcript levels in their targets, ARF10 and TIR1, respectively. The more susceptible cultivar exhibited the opposite pattern. The cis-regulatory elements relevant to defense and stress responsiveness, fungal elicitor responsiveness and hormonal responses were the most prevalent present in the miRNAs gene promoter regions. The possible dual role of these specific miRNAs and their target genes associated with cassava responses to C. gloeosporioides is discussed. This is the first study to address the molecular events by which miRNAs which might play a role in fungal-infected cassava. A better understanding of the functions of miRNAs target genes should greatly increase our knowledge of the mechanism underlying susceptibility and lead to new strategies to enhance disease tolerance in this economically important crop. Copyright © 2014 Elsevier GmbH. All

  2. Transcriptome responses of an ungrafted Phytophthora root rot tolerant avocado (Persea americana) rootstock to flooding and Phytophthora cinnamomi.

    PubMed

    Reeksting, B J; Olivier, N A; van den Berg, N

    2016-09-22

    Avocado (Persea americana Mill.) is a commercially important fruit crop worldwide. A major limitation to production is the oomycete Phytophthora cinnamomi, which causes root rot leading to branch-dieback and tree death. The decline of orchards infected with P. cinnamomi occurs much faster when exposed to flooding, even if flooding is only transient. Flooding is a multifactorial stress compromised of several individual stresses, making breeding and selection for tolerant varieties challenging. With more plantations occurring in marginal areas, with imperfect irrigation and drainage, understanding the response of avocado to these stresses will be important for the industry. Maintenance of energy production was found to be central in the response to flooding, as seen by up-regulation of transcripts related to glycolysis and induction of transcripts related to ethanolic fermentation. Energy-intensive processes were generally down-regulated, as evidenced by repression of transcripts related to processes such as secondary cell-wall biosynthesis as well as defence-related transcripts. Aquaporins were found to be down-regulated in avocado roots exposed to flooding, indicating reduced water-uptake under these conditions. The transcriptomic response of avocado to flooding and P. cinnamomi was investigated utilizing microarray analysis. Differences in the transcriptome caused by the presence of the pathogen were minor compared to transcriptomic perturbations caused by flooding. The transcriptomic response of avocado to flooding reveals a response to flooding that is conserved in several species. This data could provide key information that could be used to improve selection of stress tolerant rootstocks in the avocado industry.

  3. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white rot/ brown rot paradigm for wood decay fungi

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Riley, Robert; Salamov, Asaf; Brown, Daren W.

    Basidiomycota (basidiomycetes) make up 32percent of the described fungi and include most wood decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white rot/brown rotmore » classification paradigm we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically-informed Principal Components Analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs, but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown rot fungi. Our results suggest a continuum rather than a dichotomy between the white rot and brown rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay.« less

  4. Postharvest respiration rate and sucrose content of Rhizoctonia-infected sugarbeet roots

    USDA-ARS?s Scientific Manuscript database

    Rhizotonia crown and root rot of sugarbeet (Beta vulgaris L), caused by Rhizoctonia solani AG 2-2, is increasing in Minnesota and North Dakota. As the disease increases in prevalence and severity, more diseased roots are being stored in piles where they affect storability and postharvest quality. T...

  5. Postharvest respiration rate and sucrose content of Rhizoctonia-infected sugarbeet roots

    USDA-ARS?s Scientific Manuscript database

    Rhizotonia crown and root rot of sugarbeet, caused by Rhizoctonia solani AG 2-2, is increasing in Minnesota and North Dakota. As the disease increases in prevalence and severity, more diseased roots are being stored in piles where they affect storability and postharvest quality. The objective of th...

  6. Colonization of Clonostachys rosea on soybean root inoculated with Fusarium graminearum

    USDA-ARS?s Scientific Manuscript database

    Soybean root rot, caused by Fusarium graminearum, is a devastating disease. Clonostachys rosea has been reported to have protection against plant pathogens in different crops. The objectives of this study were to determine if a strain of C. rosea (ACM941) can colonize soybean root that were inocula...

  7. Involvement of phenazines and lipopeptides in interactions between Pseudomonas species and Sclerotium rolfsii, causal agent of stem rot disease on groundnut.

    PubMed

    Le, C N; Kruijt, M; Raaijmakers, J M

    2012-02-01

    To determine the role of phenazines (PHZ) and lipopeptide surfactants (LPs) produced by Pseudomonas in suppression of stem rot disease of groundnut, caused by the fungal pathogen Sclerotium rolfsii. In vitro assays showed that PHZ-producing Pseudomonas chlororaphis strain Phz24 significantly inhibited hyphal growth of S. rolfsii and suppressed stem rot disease of groundnut under field conditions. Biosynthesis and regulatory mutants of Phz24 deficient in PHZ production were less effective in pathogen suppression. Pseudomonas strains SS101, SBW25 and 267, producing viscosin or putisolvin-like LPs, only marginally inhibited hyphal growth of S. rolfsii and did not suppress stem rot disease. In contrast, Pseudomonas strain SH-C52, producing the chlorinated LP thanamycin, inhibited hyphal growth of S. rolfsii and significantly reduced stem rot disease of groundnut in nethouse and field experiments, whereas its thanamycin-deficient mutant was less effective. Phenazines and specific lipopeptides play an important role in suppression of stem rot disease of groundnut by root-colonizing Pseudomonas strains. Pseudomonas strains Phz24 and SH-C52 showed significant control of stem rot disease. Treatment of seeds or soil with these strains provides a promising supplementary strategy to control stem rot disease of groundnut. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  8. Regeneration of Cassava Plants from Apical Meristems,

    DTIC Science & Technology

    widely for human consumption. Propagation through stem cuttings encourages the spread of many virus diseases, such as cassava mosaic virus. This paper reports on procedures for regenerating cassava plants from the apical meristems.

  9. Novel Bioengineered Cassava Expressing an Archaeal Starch Degradation System and a Bacterial ADP-Glucose Pyrophosphorylase for Starch Self-Digestibility and Yield Increase.

    PubMed

    Ligaba-Osena, Ayalew; Jones, Jenna; Donkor, Emmanuel; Chandrayan, Sanjeev; Pole, Farris; Wu, Chang-Hao; Vieille, Claire; Adams, Michael W W; Hankoua, Bertrand B

    2018-01-01

    To address national and global low-carbon fuel targets, there is great interest in alternative plant species such as cassava ( Manihot esculenta ), which are high-yielding, resilient, and are easily converted to fuels using the existing technology. In this study the genes encoding hyperthermophilic archaeal starch-hydrolyzing enzymes, α-amylase and amylopullulanase from Pyrococcus furiosus and glucoamylase from Sulfolobus solfataricus , together with the gene encoding a modified ADP-glucose pyrophosphorylase ( glgC ) from Escherichia coli , were simultaneously expressed in cassava roots to enhance starch accumulation and its subsequent hydrolysis to sugar. A total of 13 multigene expressing transgenic lines were generated and characterized phenotypically and genotypically. Gene expression analysis using quantitative RT-PCR showed that the microbial genes are expressed in the transgenic roots. Multigene-expressing transgenic lines produced up to 60% more storage root yield than the non-transgenic control, likely due to glgC expression. Total protein extracted from the transgenic roots showed up to 10-fold higher starch-degrading activity in vitro than the protein extracted from the non-transgenic control. Interestingly, transgenic tubers released threefold more glucose than the non-transgenic control when incubated at 85°C for 21-h without exogenous application of thermostable enzymes, suggesting that the archaeal enzymes produced in planta maintain their activity and thermostability.

  10. High-throughput sequencing of black pepper root transcriptome

    PubMed Central

    2012-01-01

    Background Black pepper (Piper nigrum L.) is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host’s root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. Results The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant’s root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. Conclusions This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms. PMID:22984782

  11. Molecular cloning and characterization of a novel RING zinc-finger protein gene up-regulated under in vitro salt stress in cassava.

    PubMed

    dos Reis, Sávio Pinho; Tavares, Liliane de Souza Conceição; Costa, Carinne de Nazaré Monteiro; Brígida, Aílton Borges Santa; de Souza, Cláudia Regina Batista

    2012-06-01

    Cassava (Manihot esculenta Crantz) is one of the world's most important food crops. It is cultivated mainly in developing countries of tropics, since its root is a major source of calories for low-income people due to its high productivity and resistance to many abiotic and biotic factors. A previous study has identified a partial cDNA sequence coding for a putative RING zinc finger in cassava storage root. The RING zinc finger protein is a specialized type of zinc finger protein found in many organisms. Here, we isolated the full-length cDNA sequence coding for M. esculenta RZF (MeRZF) protein by a combination of 5' and 3' RACE assays. BLAST analysis showed that its deduced amino acid sequence has a high level of similarity to plant proteins of RZF family. MeRZF protein contains a signature sequence motif for a RING zinc finger at its C-terminal region. In addition, this protein showed a histidine residue at the fifth coordination site, likely belonging to the RING-H2 subgroup, as confirmed by our phylogenetic analysis. There is also a transmembrane domain in its N-terminal region. Finally, semi-quantitative RT-PCR assays showed that MeRZF expression is increased in detached leaves treated with sodium chloride. Here, we report the first evidence of a RING zinc finger gene of cassava showing potential role in response to salt stress.

  12. Neurochemical and behavioural correlates in cassava-induced neurotoxicity in rats.

    PubMed

    Mathangi, D C; Namasivayam, A

    2000-01-01

    Chronic cyanide intoxication from cassava has been implicated as the cause for a degenerative neuropathy known widely as tropical ataxic neuropathy. An attempt has been made in this study to identify the specific cause for neuropathy caused by cassava using Wistar strain albino rats as the experimental animal model. The results of cassava fed animals were compared with control animals, animals given cyanide, malnourished animals and malnourished animals fed cyanide, to identify the causative factors. This study revealed that though the behavioural pattern in motor coordination of the cassava fed animals was similar to the other groups studied, the neurochemical basis for the observed behavioural pattern was unique for cassava. Hence the neurotoxicity of cassava could be attributed to unmetabolized linamarin, more than its nutritional status and/or cyanide toxicity.

  13. Postharvest respiration rate and sucrose concentration of Rhizoctonia-infected sugar beet roots

    USDA-ARS?s Scientific Manuscript database

    Rhizoctonia crown and root rot (RCRR), caused by Rhizoctonia solani AG 2-2, is a common root disease on sugar beet that reduces yield and sucrose during the growing season and causes further losses by increasing respiration and reducing sucrose content during storage. The industry needs to identify...

  14. 7 CFR 29.6039 - Stem rot.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  15. 7 CFR 29.6039 - Stem rot.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  16. 7 CFR 29.6039 - Stem rot.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  17. 7 CFR 29.6039 - Stem rot.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  18. 7 CFR 29.6039 - Stem rot.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  19. High-resolution linkage map and chromosome-scale genome assembly for cassava (Manihot esculenta Crantz) from 10 populations.

    PubMed

    2014-12-11

    Cassava (Manihot esculenta Crantz) is a major staple crop in Africa, Asia, and South America, and its starchy roots provide nourishment for 800 million people worldwide. Although native to South America, cassava was brought to Africa 400-500 years ago and is now widely cultivated across sub-Saharan Africa, but it is subject to biotic and abiotic stresses. To assist in the rapid identification of markers for pathogen resistance and crop traits, and to accelerate breeding programs, we generated a framework map for M. esculenta Crantz from reduced representation sequencing [genotyping-by-sequencing (GBS)]. The composite 2412-cM map integrates 10 biparental maps (comprising 3480 meioses) and organizes 22,403 genetic markers on 18 chromosomes, in agreement with the observed karyotype. We used the map to anchor 71.9% of the draft genome assembly and 90.7% of the predicted protein-coding genes. The chromosome-anchored genome sequence will be useful for breeding improvement by assisting in the rapid identification of markers linked to important traits, and in providing a framework for genomic selection-enhanced breeding of this important crop. Copyright © 2015 International Cassava Genetic Map Consortium (ICGMC).

  20. Root disease and exotic ecosystems: implications for long-term site productivity

    Treesearch

    W.J. Otrosina; M. Garbelotto

    1998-01-01

    Root disease fungi, particularly root-rotting Basidiomycetes, are key drivers of forest ecosystems. These fungi have co?evolved with their hosts in various forest ecosystems and are in various states of equilibrium with them. Management activities and various land uses have taken place in recent times that have dramatically altered edaphic and environmental conditions...

  1. Comparing the regional epidemiology of the cassava mosaic and cassava brown streak virus pandemics in Africa.

    PubMed

    Legg, J P; Jeremiah, S C; Obiero, H M; Maruthi, M N; Ndyetabula, I; Okao-Okuja, G; Bouwmeester, H; Bigirimana, S; Tata-Hangy, W; Gashaka, G; Mkamilo, G; Alicai, T; Lava Kumar, P

    2011-08-01

    The rapid geographical expansion of the cassava mosaic disease (CMD) pandemic, caused by cassava mosaic geminiviruses, has devastated cassava crops in 12 countries of East and Central Africa since the late 1980s. Region-level surveys have revealed a continuing pattern of annual spread westward and southward along a contiguous 'front'. More recently, outbreaks of cassava brown streak disease (CBSD) were reported from Uganda and other parts of East Africa that had been hitherto unaffected by the disease. Recent survey data reveal several significant contrasts between the regional epidemiology of these two pandemics: (i) severe CMD radiates out from an initial centre of origin, whilst CBSD seems to be spreading from independent 'hot-spots'; (ii) the severe CMD pandemic has arisen from recombination and synergy between virus species, whilst the CBSD pandemic seems to be a 'new encounter' situation between host and pathogen; (iii) CMD pandemic spread has been tightly linked with the appearance of super-abundant Bemisia tabaci whitefly vector populations, in contrast to CBSD, where outbreaks have occurred 3-12 years after whitefly population increases; (iv) the CMGs causing CMD are transmitted in a persistent manner, whilst the two cassava brown streak viruses appear to be semi-persistently transmitted; and (v) different patterns of symptom expression mean that phytosanitary measures could be implemented easily for CMD but have limited effectiveness, whereas similar measures are difficult to apply for CBSD but are potentially very effective. An important similarity between the pandemics is that the viruses occurring in pandemic-affected areas are also found elsewhere, indicating that contrary to earlier published conclusions, the viruses per se are unlikely to be the key factors driving the two pandemics. A diagrammatic representation illustrates the temporal relationship between B. tabaci abundance and changing incidences of both CMD and CBSD in the Great Lakes region

  2. QTL mapping of fruit rot resistance to the plant pathogen Phytophthora capsici in a recombinant inbred line Capsicum annuum population.

    PubMed

    Naegele, R P; Ashrafi, H; Hill, T A; Chin-Wo, S Reyes; Van Deynze, A E; Hausbeck, M K

    2014-05-01

    Phytophthora capsici is an important pepper (Capsicum annuum) pathogen causing fruit and root rot, and foliar blight in field and greenhouse production. Previously, an F6 recombinant inbred line population was evaluated for fruit rot susceptibility. Continuous variation among lines and partial and isolate-specific resistance were found. In this study, Phytophthora fruit rot resistance was mapped in the same F6 population between Criollo del Morelos 334 (CM334), a landrace from Mexico, and 'Early Jalapeno' using a high-density genetic map. Isolate-specific resistance was mapped independently in 63 of the lines evaluated and the two parents. Heritability of the resistance for each isolate at 3 and 5 days postinoculation (dpi) was high (h(2) = 0.63 to 0.68 and 0.74 to 0.83, respectively). Significant additive and epistatic quantitative trait loci (QTL) were identified for resistance to isolates OP97 and 13709 (3 and 5 dpi) and 12889 (3 dpi only). Mapping of fruit traits showed potential linkage with few disease resistance QTL. The partial fruit rot resistance from CM334 suggests that this may not be an ideal source for fruit rot resistance in pepper.

  3. Digestibility of starches isolated from stem and root tubers of arracacha, cassava, cush-cush yam, potato and taro.

    PubMed

    Lovera, Mighay; Pérez, Elevina; Laurentin, Alexander

    2017-11-15

    Digestibility of arracacha, cassava, cush-cush yam, potato and taro starches was evaluated. In vitro (potentially-available starch and total resistant starch) and in vivo digestibility in the rice weevil (Sitophilus oryzae) bioassay (survival, weight variation, α-amylase like activity [ALA], and uric acid excretion [UAE] as biomarkers) were estimated. In in vitro assays, all starches presented high resistant starch content (14-56%, dry basis), except for cassava starch. In in vivo assays, cush-cush yam and potato starches promoted higher ALA (>3 times) and UAE (>4 times) compare to a reference diet (cornstarch), in agreement to their low digestibility. These two biomarkers were related with resistant starch (r>0.81) and could be used to predict the starch bioavailability. This study demonstrates that the use of both in vitro and in vivo assays allows a better evaluation of starch digestibility, and may help to elucidate the final metabolic fate of starch digestion products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Digestible and metabolizable energy concentrations in copra meal, palm kernel meal, and cassava root fed to growing pigs.

    PubMed

    Son, A R; Ji, S Y; Kim, B G

    2012-12-01

    An experiment was conducted to measure DE and ME in copra (Cocos nucifera) meal (CM), palm kernel meal (PKM), and cassava (Manihot esculenta) root (CR) in growing pigs. Eight boars with an initial BW of 67.3 ± 5.8 kg were individually housed in metabolism crates that were equipped with a feeder and a nipple drinker. A replicated 4 × 4 Latin square design was used with 4 dietary treatments, 4 periods, and 8 animals. A basal diet mainly contained corn (Zea mays) and soybean (Glycine max) meal. Three additional diets were formulated to contain 30% of CM, PKM, and CR. All diets contained the same proportion of corn:soybean meal ratio at 4.14:1. The apparent total tract digestibility of energy was 89.5, 84.1, 82.4, and 87.9% (P < 0.001) in the basal, CM, PKM, and CR diets, respectively. The DE in CM and PKM were greater (P < 0.05) than in CR (3440 and 3238 vs. 2966 kcal/kg as-fed). The ME in CM was greater (P < 0.05) than in CR (3340 vs. 2935 kcal/kg as-fed) but not different from the ME in PKM (3168 kcal/kg as-fed). In conclusion, CM and PKM have a higher DE value than CR, and CM has a higher ME value than CR.

  5. Pruning of Manchurian crabapple for management of speck rot and Sphaeropsis rot in apple

    USDA-ARS?s Scientific Manuscript database

    Phacidiopycnis washingtonensis and Sphaeropsis pyriputrescens are two important quarantined fungal pathogens that cause post-harvest speck rot and Sphaeropsis rot, respectively, in apple. Due to detection of these pathogens in fruit shipments and quarantine regulation, export of apple from Washingto...

  6. Influence of cultural practices on edaphic factors related to root disease in Pinus nursery seedlings

    Treesearch

    J Juzwik; K. M. Gust; R. R. Allmaras

    1999-01-01

    Conifer seedlings grown in bare-root nurseries are frequently damaged and destroyed by soil-borne pathogenic fungi that cause root rot. Relationships between nursery cultural practices, soils characteristics, and populations of potential pathogens in the soil were examined in three bare-root tree nurseries in the midwestern USA. Soil-borne populations of ...

  7. The development of spectro-signature indicators of root disease

    NASA Technical Reports Server (NTRS)

    Wear, J. F.

    1968-01-01

    The development and testing of airborne sensors that might be effective in discrimination root rot infected trees from healthy ones are outlined. The sensing device is composed of a thermal infrared radiometer and an instant replay video scan system.

  8. Red Rot of Ponderosa Pine (FIDL)

    Treesearch

    Stuart R. Andrews

    1971-01-01

    Red rot caused by the fungus Polyporus anceps Peck is the most important heart rot of ponderosa pine (Pinus ponderosa Laws.) in the Southwest (in Arizona and New Mexico), the Black Hills of South Dakota, and some localities in Colorado, Montana, and Idaho. It causes only insignificant losses to this species elsewhere in the West. The red rot fungus rarely attacks other...

  9. Production of raw cassava starch-degrading enzyme by Penicillium and its use in conversion of raw cassava flour to ethanol.

    PubMed

    Lin, Hai-Juan; Xian, Liang; Zhang, Qiu-Jiang; Luo, Xue-Mei; Xu, Qiang-Sheng; Yang, Qi; Duan, Cheng-Jie; Liu, Jun-Liang; Tang, Ji-Liang; Feng, Jia-Xun

    2011-06-01

    A newly isolated strain Penicillium sp. GXU20 produced a raw starch-degrading enzyme which showed optimum activity towards raw cassava starch at pH 4.5 and 50 °C. Maximum raw cassava starch-degrading enzyme (RCSDE) activity of 20 U/ml was achieved when GXU20 was cultivated under optimized conditions using wheat bran (3.0% w/v) and soybean meal (2.5% w/v) as carbon and nitrogen sources at pH 5.0 and 28 °C. This represented about a sixfold increment as compared with the activity obtained under basal conditions. Starch hydrolysis degree of 95% of raw cassava flour (150 g/l) was achieved after 72 h of digestion by crude RCSDE (30 U/g flour). Ethanol yield reached 53.3 g/l with fermentation efficiency of 92% after 48 h of simultaneous saccharification and fermentation of raw cassava flour at 150 g/l using the RCSDE (30 U/g flour), carried out at pH 4.0 and 40 °C. This strain and its RCSDE have potential applications in processing of raw cassava starch to ethanol.

  10. Novel Bioengineered Cassava Expressing an Archaeal Starch Degradation System and a Bacterial ADP-Glucose Pyrophosphorylase for Starch Self-Digestibility and Yield Increase

    PubMed Central

    Ligaba-Osena, Ayalew; Jones, Jenna; Donkor, Emmanuel; Chandrayan, Sanjeev; Pole, Farris; Wu, Chang-Hao; Vieille, Claire; Adams, Michael W. W.; Hankoua, Bertrand B.

    2018-01-01

    To address national and global low-carbon fuel targets, there is great interest in alternative plant species such as cassava (Manihot esculenta), which are high-yielding, resilient, and are easily converted to fuels using the existing technology. In this study the genes encoding hyperthermophilic archaeal starch-hydrolyzing enzymes, α-amylase and amylopullulanase from Pyrococcus furiosus and glucoamylase from Sulfolobus solfataricus, together with the gene encoding a modified ADP-glucose pyrophosphorylase (glgC) from Escherichia coli, were simultaneously expressed in cassava roots to enhance starch accumulation and its subsequent hydrolysis to sugar. A total of 13 multigene expressing transgenic lines were generated and characterized phenotypically and genotypically. Gene expression analysis using quantitative RT-PCR showed that the microbial genes are expressed in the transgenic roots. Multigene-expressing transgenic lines produced up to 60% more storage root yield than the non-transgenic control, likely due to glgC expression. Total protein extracted from the transgenic roots showed up to 10-fold higher starch-degrading activity in vitro than the protein extracted from the non-transgenic control. Interestingly, transgenic tubers released threefold more glucose than the non-transgenic control when incubated at 85°C for 21-h without exogenous application of thermostable enzymes, suggesting that the archaeal enzymes produced in planta maintain their activity and thermostability. PMID:29541080

  11. Data analysis on physical and mechanical properties of cassava pellets.

    PubMed

    Oguntunde, Pelumi E; Adejumo, Oluyemisi A; Odetunmibi, Oluwole A; Okagbue, Hilary I; Adejumo, Adebowale O

    2018-02-01

    In this data article, laboratory experimental investigation results carried out at National Centre for Agricultural Mechanization (NCAM) on moisture content, machine speed, die diameter of the rig, and the outputs (hardness, durability, bulk density, and unit density of the pellets) at different levels of cassava pellets were observed. Analysis of variance using randomized complete block design with factorial was used to perform analysis for each of the outputs: hardness, durability, bulk density, and unit density of the pellets. A clear description on each of these outputs was considered separately using tables and figures. It was observed that for all the output with the exception of unit density, their main factor effects as well as two and three ways interactions is significant at 5% level. This means that the hardness, bulk density and durability of cassava pellets respectively depend on the moisture content of the cassava dough, the machine speed, the die diameter of the extrusion rig and the combinations of these factors in pairs as well as the three altogether. Higher machine speeds produced more quality pellets at lower die diameters while lower machine speed is recommended for higher die diameter. Also the unit density depends on die diameter and the three-way interaction only. Unit density of cassava pellets is neither affected by machine parameters nor moisture content of the cassava dough. Moisture content of cassava dough, speed of the machine and die diameter of the extrusion rig are significant factors to be considered in pelletizing cassava to produce pellets. Increase in moisture content of cassava dough increase the quality of cassava pellets.

  12. Transcriptome profiling of low temperature-treated cassava apical shoots showed dynamic responses of tropical plant to cold stress

    PubMed Central

    2012-01-01

    Background Cassava is an important tropical root crop adapted to a wide range of environmental stimuli such as drought and acid soils. Nevertheless, it is an extremely cold-sensitive tropical species. Thus far, there is limited information about gene regulation and signalling pathways related to the cold stress response in cassava. The development of microarray technology has accelerated the study of global transcription profiling under certain conditions. Results A 60-mer oligonucleotide microarray representing 20,840 genes was used to perform transcriptome profiling in apical shoots of cassava subjected to cold at 7°C for 0, 4 and 9 h. A total of 508 transcripts were identified as early cold-responsive genes in which 319 sequences had functional descriptions when aligned with Arabidopsis proteins. Gene ontology annotation analysis identified many cold-relevant categories, including 'Response to abiotic and biotic stimulus', 'Response to stress', 'Transcription factor activity', and 'Chloroplast'. Various stress-associated genes with a wide range of biological functions were found, such as signal transduction components (e.g., MAP kinase 4), transcription factors (TFs, e.g., RAP2.11), and reactive oxygen species (ROS) scavenging enzymes (e.g., catalase 2), as well as photosynthesis-related genes (e.g., PsaL). Seventeen major TF families including many well-studied members (e.g., AP2-EREBP) were also involved in the early response to cold stress. Meanwhile, KEGG pathway analysis uncovered many important pathways, such as 'Plant hormone signal transduction' and 'Starch and sucrose metabolism'. Furthermore, the expression changes of 32 genes under cold and other abiotic stress conditions were validated by real-time RT-PCR. Importantly, most of the tested stress-responsive genes were primarily expressed in mature leaves, stem cambia, and fibrous roots rather than apical buds and young leaves. As a response to cold stress in cassava, an increase in transcripts and

  13. Chemical safety of cassava products in regions adopting cassava production and processing--experience from Southern Africa.

    PubMed

    Nyirenda, D B; Chiwona-Karltun, L; Chitundu, M; Haggblade, S; Brimer, L

    2011-03-01

    The cassava belt area in Southern Africa is experiencing an unforeseen surge in cassava production, processing and consumption. Little documentation exists on the effects of this surge on processing procedures, the prevailing levels of cyanogenic glucosides of products consumed and the levels of products commercially available on the market. Risk assessments disclose that effects harmful to the developing central nervous system (CNS) may be observed at a lower exposure than previously anticipated. We interviewed farmers in Zambia and Malawi about their cultivars, processing procedures and perceptions concerning cassava and chemical food safety. Chips, mixed biscuits and flour, procured from households and markets in three regions of Zambia (Luapula-North, Western and Southern) as well as products from the Northern, Central and Southern regions of Malawi, were analyzed for total cyanogenic potential (CNp). Processed products from Luapula showed a low CNp, <10 mg HCN equiv./kg air dried weight, while samples from Mongu, Western Province, exhibited high levels of CNp, varying from 50 to 290 mg HCN equiv./kg. Even the lowest level is five times higher than the recommended safety level of 10mg/kg decided on for cassava flour. Our results call for concerted efforts in promoting gender oriented processing technologies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Overproduction of superoxide dismutase and catalase confers cassava resistance to Tetranychus cinnabarinus

    PubMed Central

    Lu, Fuping; Liang, Xiao; Lu, Hui; Li, Qian; Chen, Qing; Zhang, Peng; Li, kaimian; Liu, Guanghua; Yan, Wei; Song, Jiming; Duan, Chunfang; Zhang, Linhui

    2017-01-01

    To explore the role of protective enzymes in cassava (Manihot esculenta Crantz) resistance to mites, transgenic cassava lines overproducing copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) were used to evaluate and molecularly confirm cassava resistance to Tetranychus cinnabarinus. Laboratory evaluation demonstrated that, compared with the control cultivar TMS60444 (wild type, WT), the survival, reproduction, development and activities of SOD and CAT in T. cinnabarinus feeding on transgenic cassava lines SC2, SC4, and SC11 significantly inhibited. Furthermore, the activities of SOD and CAT in transgenic cassava lines SC2, SC4, and SC11 damaged by T. cinnabarinus significantly increased. These findings were similar to the results in the mite-resistant cassava cultivars. Besides, field evaluation indicated that the transgenic cassava lines SC2, SC4, and SC11 were slightly damaged as the highly mite-resistant control C1115, while the highly mite-susceptible WT was severely damaged by T. cinnabarinus. Laboratory and field evaluation demonstrated that transgenic cassava lines were resistant to T. cinnabarinus, which directly confirmed that the increase in SOD and CAT activities was positively related to cassava resistance to T. cinnabarinus. These results will help in understanding the antioxidant defense responses in the cassava–mite interaction and molecular breeding of mite-resistant cassava for effective pest control. PMID:28054665

  15. Digestibility and metabolizable energy values of processed cassava chips for growing and finishing pigs.

    PubMed

    Lokaewmanee, Kanda; Kanto, Uthai; Juttupornpong, Sukanya; Yamauchi, Koh-en

    2011-02-01

    Determinations of digestibility of dry matter (DM), digestible energy (DE), and metabolizable energy (ME) in cassava chips with different levels of crude fiber (CF) were measured in growing pigs (20 kg) and finishing pigs (60 kg). The treatments were (1) cassava starch (0% CF), (2) peeled cassava chips (2.5% CF), (3) non-peeled washed cassava chips (3.9% CF), and (4) non-peeled and non-washed cassava chips (5.2% CF). In the growing pigs, peeled cassava chips, non-peeled washed cassava chips, and non-peeled and non-washed cassava chips had DM digestibility of 87.51%, 78.63%, and 73.89%, respectively. Their DE was 3.69, 3.49, and 3.32 Mcal/kg DM, respectively (DE of cassava starch is 3.90 Mcal/kg DM). ME was 3.54, 3.35, and 3.19 Mcal/kg DM, respectively (ME of cassava starch is 3.74 Mcal/kg DM). On the other hand, in the finishing pigs, the digestibility of DM was 89.13%, 80.63%, and 76.13%, respectively. Their DE was 3.72, 3.53, and 3.43 Mcal/kg DM, respectively (DE of cassava starch is 3.91 Mcal/kg DM). ME was 3.57, 3.38, and 3.29 Mcal/kg DM, respectively (ME of cassava starch is 3.75 Mcal/kg DM). These values increased with decreasing CF content, and the peeled cassava chips had the highest values (P < 0.01). These suggest that the digestibility values of DM, DE, and ME of cassava chips is inversely related to the CF content in cassava chips. It is recommended that cassava chips be peeled for better nutrition for growing and finishing pigs.

  16. Genetic diversity analysis of cyanogenic potential (CNp) of root among improved genotypes of cassava using simple sequence repeat markers.

    PubMed

    Moyib, O K; Mkumbira, J; Odunola, O A; Dixon, A G

    2012-12-01

    Cyanogenic potential (CNp) of cassava constitutes a serious problem for over 500 million people who rely on the crop as their main source of calories. Genetic diversity is a key to successful crop improvement for breeding new improved variability for target traits. Forty-three improved genotypes of cassava developed by International Institute of Tropical Agriculture (ITA), Ibadan, were characterized for CNp trait using 35 Simple Sequence.Repeat (SSR) markers. Essential colorimetry picric test was used for evaluation of CNp on a color scale of 1 to 14. The CNp scores obtained ranged from 3 to 9, with a mean score of 5.48 (+/- 0.09) based on Statistical Analysis System (SAS) package. TMS M98/ 0068 (4.0 +/- 0.25) was identified as the best genotype with low CNp while TMS M98/0028 (7.75 +/- 0.25) was the worst. The 43 genotypes were assigned into 7 phenotypic groups based on rank-sum analysis in SAS. Dissimilarity analysis representatives for windows generated a phylogenetic tree with 5 clusters which represented hybridizing groups. Each of the clusters (except 4) contained low CNp genotypes that could be used for improving the high CNp genotypes in the same or near cluster. The scatter plot of the genotypes showed that there was little or no demarcation for phenotypic CNp groupings in the molecular groupings. The result of this study demonstrated that SSR markers are powerful tools for the assessment of genetic variability, and proper identification and selection of parents for genetic improvement of low CNp trait among the IITA cassava collection.

  17. Deep Learning for Image-Based Cassava Disease Detection.

    PubMed

    Ramcharan, Amanda; Baranowski, Kelsee; McCloskey, Peter; Ahmed, Babuali; Legg, James; Hughes, David P

    2017-01-01

    Cassava is the third largest source of carbohydrates for human food in the world but is vulnerable to virus diseases, which threaten to destabilize food security in sub-Saharan Africa. Novel methods of cassava disease detection are needed to support improved control which will prevent this crisis. Image recognition offers both a cost effective and scalable technology for disease detection. New deep learning models offer an avenue for this technology to be easily deployed on mobile devices. Using a dataset of cassava disease images taken in the field in Tanzania, we applied transfer learning to train a deep convolutional neural network to identify three diseases and two types of pest damage (or lack thereof). The best trained model accuracies were 98% for brown leaf spot (BLS), 96% for red mite damage (RMD), 95% for green mite damage (GMD), 98% for cassava brown streak disease (CBSD), and 96% for cassava mosaic disease (CMD). The best model achieved an overall accuracy of 93% for data not used in the training process. Our results show that the transfer learning approach for image recognition of field images offers a fast, affordable, and easily deployable strategy for digital plant disease detection.

  18. Monitoring cotton root rot by synthetic Sentinel-2 NDVI time series using improved spatial and temporal data fusion.

    PubMed

    Wu, Mingquan; Yang, Chenghai; Song, Xiaoyu; Hoffmann, Wesley Clint; Huang, Wenjiang; Niu, Zheng; Wang, Changyao; Li, Wang; Yu, Bo

    2018-01-31

    To better understand the progression of cotton root rot within the season, time series monitoring is required. In this study, an improved spatial and temporal data fusion approach (ISTDFA) was employed to combine 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Different Vegetation Index (NDVI) and 10-m Sentinetl-2 NDVI data to generate a synthetic Sentinel-2 NDVI time series for monitoring this disease. Then, the phenology of healthy cotton and infected cotton was modeled using a logistic model. Finally, several phenology parameters, including the onset day of greenness minimum (OGM), growing season length (GLS), onset of greenness increase (OGI), max NDVI value, and integral area of the phenology curve, were calculated. The results showed that ISTDFA could be used to combine time series MODIS and Sentinel-2 NDVI data with a correlation coefficient of 0.893. The logistic model could describe the phenology curves with R-squared values from 0.791 to 0.969. Moreover, the phenology curve of infected cotton showed a significant difference from that of healthy cotton. The max NDVI value, OGM, GSL and the integral area of the phenology curve for infected cotton were reduced by 0.045, 30 days, 22 days, and 18.54%, respectively, compared with those for healthy cotton.

  19. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi

    Treesearch

    Robert Riley; Asaf A. Salamov; Daren W. Brown; Laszlo G. Nagy; Dimitrios Floudas; Benjamin W. Held; Anthony Levasseur; Vincent Lombard; Emmanuelle Morin; Robert Otillar; Erika A. Lindquist; Hui Sun; Kurt M. LaButti; Jeremy Schmutz; Dina Jabbour; Hong Luo; Scott E. Baker; Antonio G. Pisabarro; Jonathan D. Walton; Robert A. Blanchette; Bernard Henrissat; Francis Martin; Daniel Cullen; David S. Hibbett; Igor V. Grigoriev

    2014-01-01

    Basidiomycota (basidiomycetes) make up 32% of the described fungi and include most wood-decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic...

  20. Cassava/sugar palm fiber reinforced cassava starch hybrid composites: Physical, thermal and structural properties.

    PubMed

    Edhirej, Ahmed; Sapuan, S M; Jawaid, Mohammad; Zahari, Nur Ismarrubie

    2017-08-01

    A hybrid composite was prepared from cassava bagasse (CB) and sugar palm fiber (SPF) using casting technique with cassava starch (CS) as matrix and fructose as a plasticizer. Different loadings of SPF (2, 4, 6 and 8% w/w of dry starch) were added to the CS/CB composite film containing 6% CB. The addition of SPF significantly influenced the physical properties. It increased the thickness while decreasing the density, water content, water solubility and water absorption. However, no significant effect was noticed on the thermal properties of the hybrid composite film. The incorporation of SPF increased the relative crystallinity up to 47%, compared to 32% of the CS film. SEM micrographs indicated that the filler was incorporated in the matrix. The film with a higher concentration of SPF (CS-CB/SPF8) showed a more heterogeneous surface. It could be concluded that the incorporation of SPF led to changes in cassava starch film properties, potentially affecting the film performances. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Effect of cyanogenic glycosides and protein content in cassava diets on hamster prenatal development.

    PubMed

    Frakes, R A; Sharma, R P; Willhite, C C; Gomez, G

    1986-08-01

    Cassava is a staple food for 450-500 million people in 26 tropical countries. Groups of pregnant hamsters were fed diets consisting of cassava meal:laboratory chow (80:20) during Days 3-14 of gestation. One low cyanide (sweet) cassava meal and one high cyanide (bitter) cassava meal were studied. One additional group was fed a diet which resembled cassava in nutritional value, but which lacked the cyanogenic glycosides. Thiocyanate concentrations increased significantly in the urine and blood of dams fed cassava diets. Increased tissue thiocyanate concentrations were observed in fetuses recovered from cassava-fed dams. Cassava-fed dams gained significantly less weight than did control animals and their offspring showed evidence of fetotoxicity. Reduced fetal body weight and reduced ossification of sacrocaudal vertebrae, metatarsals, and sternebrae were associated with cassava diets. High cyanide cassava diets were also associated with a significant increase in the numbers of runts compared to litters from dams fed either low protein or laboratory stock diets.

  2. Konzo and continuing cyanide intoxication from cassava in Mozambique.

    PubMed

    Cliff, J; Muquingue, H; Nhassico, D; Nzwalo, H; Bradbury, J H

    2011-03-01

    In Mozambique, epidemics of the cassava-associated paralytic disease, konzo, have been reported in association with drought or war: over 1100 cases in 1981, over 600 cases in 1992-1993, and over 100 cases in 2005. Smaller epidemics and sporadic cases have also been reported. Large epidemics have occurred at times of agricultural crisis, during the cassava harvest, when the population has been dependent on a diet of insufficiently processed bitter cassava. Konzo mostly affects women of child-bearing age and children over 2 years of age. When measured, serum or urinary thiocyanate concentrations, indicative of cyanide poisoning, have been high in konzo patients during epidemics and in succeeding years. Monitoring of urinary thiocyanate concentrations in schoolchildren in konzo areas has shown persistently high concentrations at the time of the cassava harvest. Inorganic sulphate concentrations have been low during and soon after epidemics. Programmes to prevent konzo have focused on distributing less toxic varieties of cassava and disseminating new processing methods, such as grating and the flour wetting method. Attention should be given to the wider question of agricultural development and food security in the regions of Africa where dependence on bitter cassava results in chronic cyanide intoxication and persistent and emerging konzo. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Cassava haplotype map highlights fixation of deleterious mutations during clonal propagation

    USDA-ARS?s Scientific Manuscript database

    Cassava (Manihot esculenta Crantz) is an important staple food crop in Africa and South America whose fitness may be severely reduced by ubiquitous deleterious variation. To evaluate these deleterious mutations in cassava genome, we constructed a cassava haplotype map by deep sequencing of 241 diver...

  4. Pyramiding Sclerotinia head rot and stalk rot resistances into elite sunflower breeding lines with the aid of DNA markers

    USDA-ARS?s Scientific Manuscript database

    Work was conducted in 2008 to determine the stalk rot resistance of RILs from the RHA 280 x RHA 801 population, as well as to begin introgression of previously identified QTL for head rot resistance into elite sunflower germplasm lines. The stalk rot RILs and their testcrosses with cms HA 89 were t...

  5. Encapsulation of nodal cuttings and shoot tips for storage and exchange of cassava germplasm.

    PubMed

    Danso, K E; Ford-Lloyd, B V

    2003-04-01

    We report the encapsulation of in vitro-derived nodal cuttings or shoot tips of cassava in 3% calcium alginate for storage and germplasm exchange purposes. Shoot regrowth was not significantly affected by the concentration of sucrose in the alginate matrix while root formation was. In contrast, increasing the sucrose concentration in the calcium chloride polymerisation medium significantly reduced regrowth from encapsulated nodal cuttings of accession TME 60444. Supplementing the alginate matrix with increased concentrations of 6-benzylaminopurine and alpha-naphthaleneacetic acid enhanced complete plant regrowth within 2 weeks. Furthermore, plant regrowth by encapsulated nodal cuttings and shoot tips was significantly affected by the duration of the storage period as shoot recovery decreased from almost 100% to 73.3% for encapsulated nodal cuttings and 94.4% to 60% for shoot tips after 28 days of storage. The high frequency of plant regrowth from alginate-coated micropropagules coupled with high viability percentage after 28 days of storage is highly encouraging for the exchange of cassava genetic resources. Such encapsulated micropropagules could be used as an alternative to synthetic seeds derived from somatic embryos.

  6. Structural, thermal, and morphological characteristics of cassava amylodextrins.

    PubMed

    Costa, Mariana Souza; Volanti, Diogo Paschoalini; Grossmann, Maria Victória Eiras; Franco, Célia Maria Landi

    2018-05-01

    Amylodextrins from cassava starch were obtained by acid hydrolysis, and their structural, thermal and morphological characteristics were evaluated and compared to those from potato and corn amylodextrins. Cassava starch was the most susceptible to hydrolysis due to imperfections in its crystalline structure. The crystalline patterns of amylodextrins remained unchanged, and crystallinity and peak temperature increased with hydrolysis time, whereas thermal degradation temperature decreased, independent of treatment time and starch source. Cassava amylodextrins had similar structural and morphological characteristics to those from corn amylodextrins due to their A-type crystalline arrangements. A-amylodextrins were structurally and thermally more stable than potato amylodextrins (B-type). Starch nanocrystals (SNC) were observed by transmission electron microscopy from the third day of hydrolysis in cassava amylodextrins, whereas potato and corn amylodextrins displayed SNC only on the fifth day. A-SNC displayed platelet shapes, whereas B-SNC were rounded. The SNC shape was related to the packing form and geometry of unit cells of allomorphs A and B. Microstructures (agglomerated crystalline particles) and nanostructures (double helix organization) were observed for amylodextrins. Cassava starch was shown to be a promising material for SNC production, since it requires less hydrolysis time to obtaining more stable crystals. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Cost analysis of cassava cellulose utilization scenarios for ethanol production on flowsheet simulation platform.

    PubMed

    Zhang, Jian; Fang, Zhenhong; Deng, Hongbo; Zhang, Xiaoxi; Bao, Jie

    2013-04-01

    Cassava cellulose accounts for one quarter of cassava residues and its utilization is important for improving the efficiency and profit in commercial scale cassava ethanol industry. In this study, three scenarios of cassava cellulose utilization for ethanol production were experimentally tested under same conditions and equipment. Based on the experimental results, a rigorous flowsheet simulation model was established on Aspen plus platform and the cost of cellulase enzyme and steam energy in the three cases was calculated. The results show that the simultaneous co-saccharification of cassava starch/cellulose and ethanol fermentation process (Co-SSF) provided a cost effective option of cassava cellulose utilization for ethanol production, while the utilization of cassava cellulose from cassava ethanol fermentation residues was not economically sound. Comparing to the current fuel ethanol selling price, the Co-SSF process may provide an important choice for enhancing cassava ethanol production efficiency and profit in commercial scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR.

    PubMed Central

    D'Souza, T M; Boominathan, K; Reddy, C A

    1996-01-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. PMID:8837429

  9. Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

    PubMed

    Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

    2011-09-28

    The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

  10. Rhizospheric soil and root endogenous fungal diversity and composition in response to continuous Panax notoginseng cropping practices.

    PubMed

    Tan, Yong; Cui, Yinshan; Li, Haoyu; Kuang, Anxiu; Li, Xiaoran; Wei, Yunlin; Ji, Xiuling

    2017-01-01

    Rhizosphere and endophytic fungal communities are considered critically important for plant health and soil fertility. In response to continuous cropping, Panax notoginseng becomes vulnerable to attack by fungal pathogens. In the present study, culture-independent Illumina MiSeq was used to investigate the rhizospheric and root endophytic fungi in response to continuous Panax notoginseng cropping practices. The results demonstrated that fungal diversity is increased inside the roots and in rhizospheric. Ascomycota, Zygomycota, Basidiomycota and Chytridiomycota were the dominant phyla detected during the continuous cropping of Panax notoginseng. The fungal diversity in the rhizospheric soil and roots of root-rot P. notoginseng plants are less than that of healthy plants in the same cultivating year, thus showing that root-rot disease also affects the community structure and diversity of rhizospheric and root endophytic fungi. Similarities in the major fungal components show that endophytic fungal communities are similar to rhizospheric soil fungal community based on a specialized subset of organisms. Canonical correspondence analysis on the fungal communities in root-rot rhizospheric from both healthy plants and rotation soils reveals that the soil pH and organic matter have the greatest impact upon the microbial community composition during continuous cropping, whereas soil nutrition status does not significantly affect the fungal community composition in response to continuous cropping practices. In addition, the results suggest that the unclassified genera Leotiomycetes, Cylindrocarpon, Fusarium and Mycocentrospora are shown as the potential pathogens which are responsible for the obstacles in continuous cropping of P. notoginseng. Further exploration of these potential pathogens might be useful for the biological control of continuous cropping of P. notoginseng. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Cassava (Manihot esculenta Crantz) and Yam (Dioscorea spp.) Crops and Their Derived Foodstuffs: Safety, Security and Nutritional Value.

    PubMed

    Ferraro, Vincenza; Piccirillo, Clara; Tomlins, Keith; Pintado, Manuela E

    2016-12-09

    Cassava (Manihot esculenta Crantz) and yam (Dioscorea spp.) are tropical crops consumed by ca. 2 billion people and represent the main source of carbohydrate and energy for the approximately 700 million people living in the tropical and sub-tropical areas. They are a guarantee of food security for developing countries. The production of these crops and the transformation into food-derived commodities is increasing, it represents a profitable business and farmers generate substantial income from their market. However, there are some important concerns related to the food safety and food security. The high post-harvest losses, mainly for yam, the contamination by endogenous toxic compounds, mainly for cassava, and the contamination by external agents (such as micotoxins, pesticides, and heavy metal) represent a depletion of economic value and income. The loss in the raw crops or the impossibility to market the derived foodstuffs, due to incompliance with food regulations, can seriously limit all yam tubers and the cassava roots processors, from farmers to household, from small-medium to large enterprises. One of the greatest challenges to overcome those concerns is the transformation of traditional or indigenous processing methods into modern industrial operations, from the crop storage to the adequate package of each derived foodstuff.

  12. Improving Genomic Prediction in Cassava Field Experiments Using Spatial Analysis.

    PubMed

    Elias, Ani A; Rabbi, Ismail; Kulakow, Peter; Jannink, Jean-Luc

    2018-01-04

    Cassava ( Manihot esculenta Crantz) is an important staple food in sub-Saharan Africa. Breeding experiments were conducted at the International Institute of Tropical Agriculture in cassava to select elite parents. Taking into account the heterogeneity in the field while evaluating these trials can increase the accuracy in estimation of breeding values. We used an exploratory approach using the parametric spatial kernels Power, Spherical, and Gaussian to determine the best kernel for a given scenario. The spatial kernel was fit simultaneously with a genomic kernel in a genomic selection model. Predictability of these models was tested through a 10-fold cross-validation method repeated five times. The best model was chosen as the one with the lowest prediction root mean squared error compared to that of the base model having no spatial kernel. Results from our real and simulated data studies indicated that predictability can be increased by accounting for spatial variation irrespective of the heritability of the trait. In real data scenarios we observed that the accuracy can be increased by a median value of 3.4%. Through simulations, we showed that a 21% increase in accuracy can be achieved. We also found that Range (row) directional spatial kernels, mostly Gaussian, explained the spatial variance in 71% of the scenarios when spatial correlation was significant. Copyright © 2018 Elias et al.

  13. Cassava starch as a stabilizer of soy-based beverages.

    PubMed

    Drunkler, Northon Lee; Leite, Rodrigo Santos; Mandarino, José Marcos Gontijo; Ida, Elza Iouko; Demiate, Ivo Mottin

    2012-10-01

    Soy-based beverages are presented as healthy food alternatives for human nutrition. Cassava (Manihot esculenta, Crantz) starch is relatively inexpensive, widely available in Brazil and is broadly used by the food industry due to its desired properties that result from pasting. The objective of this study was to develop soy-based beverages with good sensory quality using native cassava starch as a stabilizer and maintaining the nutritional value that makes this product a functional food. The developed formulations featured a range of cassava starch and soybean extract concentrations, which were tested in a 2² experimental design with three central points. The results of sensory analysis showed that the studied variables (cassava starch and soybean extract concentrations) did not have a significant effect with respect to a 5% probability level. When considering the apparent viscosity, on the other hand, the variables had a significant effect: the increase in soybean extract and cassava starch concentrations caused an increase in the viscosity of the final product. The profile of isoflavones in the tested formulations was similar to the profiles reported in other papers, with a predominance of the conjugated glycosides over the aglycone forms.

  14. A Pontential Agriculture Waste Material as Coagulant Aid: Cassava Peel

    NASA Astrophysics Data System (ADS)

    Othman, N.; Abd-Rahim, N.-S.; Tuan-Besar, S.-N.-F.; Mohd-Asharuddin, S.; Kumar, V.

    2018-02-01

    All A large amount of cassava peel waste is generated annually by small and medium scale industries. This has led to a new policy of complete utilization of raw materials so that there will be little or no residue left that could pose pollution problems. Conversion of these by-products into a material that poses an ability to remove toxic pollutant would increase the market value and ultimately benefits the producers. This study investigated the characteristics of cassava peel as a coagulant aid material and optimization process using the cassava peel was explored through coagulation and flocculation. This research had highlighted that the Cassava peels contain sugars in the form of polysaccharides such as starch and holocellulose. The FTIR results revealed that amino acids containing abundant of carboxyl, hydroxyl and amino groups which has significant capabilities in removing pollutants. Whereas analysis by XRF spectrometry indicated that the CP samples contain Fe2O3 and Al2O3 which might contribute to its coagulation ability. The optimum condition allowed Cassava peel and alum removed high turbidity up to 90. This natural coagulant from cassava peel is found to be an alternative coagulant aid to reduce the usage of chemical coagulants

  15. The contribution of moulds and yeasts to the fermentation of 'agbelima' cassava dough.

    PubMed

    Amoa-Awua, W K; Frisvad, J C; Sefa-Dedeh, S; Jakobsen, M

    1997-09-01

    Agbelima, a fermented cassava meal widely consumed in Ghana, Togo and Benin, is produced by fermenting grated cassava with one of several types of traditional cassava dough inoculum. During fermentation a smooth textured sour dough is produced, the toxicity of cassava is reduced and there is a build up of volatile aroma compounds. Four types of inocula were included in the present investigation. In one type moulds were found to form a dominant part of the microbiota, the species present being Penicillium sclerotiorum, P. citrinum, P. nodulum, Geotrichum candidum and a basidiomycete. All these moulds were found to possess cellulase activity which was responsible for the hydrolysis of cassava tuber cellulose during fermentation leading to a breakdown of the coarse texture of cassava dough. The yeasts Candida krusei, C. tropicalis and Zygosaccharomyces spp. were present in high numbers in the four types of inocula including the moudly inoculum. The yeasts C. tropicalis and some strains of Zygosaccharomyces, all of which possessed cellulase activity, were also found to contribute to the modification of cassava texture during fermentation. All yeasts and moulds exhibited linamarase activity and were therefore capable of breaking down the cyanogenic glucosides present in cassava.

  16. The effect of microbial starter composition on cassava chips fermentation for the production of fermented cassava flour

    NASA Astrophysics Data System (ADS)

    Kresnowati, M. T. A. P.; Listianingrum, Zaenudin, Ahmad; Trihatmoko, Kharisrama

    2015-12-01

    The processing of cassava into fermented cassava flour (fercaf) or the widely known as modified cassava flour (mocaf) presents an alternative solution to improve the competitiveness of local foods and to support national food security. However, the mass production of fercaf is being limited by several problems, among which is the availability of starter cultures. This paper presents the mapping of the effect of microbial starter compositions on the nutritional content of fercaf in order to obtain the suitable nutritional composition. Based on their enzymatic activities, the combination of Lactobacillus plantarum, Bacillus subtilis, and Aspergillus oryzae were tested during the study. In addition, commercial starter was also tested. During the fermentation, the dynamics in microbial population were measured as well as changes in cyanogenic glucoside content. The microbial starter composition was observed to affect the dynamics in microbial populationcynaogenic glucoside content of the produced fercaf. In general, steady state microbial population was reached within 12 hours of fermentation. Cyanogenic glucoside was observed to decrease along the fermentation.

  17. Cassava root husks powder as green adsorbent for the removal of Cu(II) from natural river water

    NASA Astrophysics Data System (ADS)

    Jorgetto, A. O.; Silva, R. I. V.; Saeki, M. J.; Barbosa, R. C.; Martines, M. A. U.; Jorge, S. M. A.; Silva, A. C. P.; Schneider, J. F.; Castro, G. R.

    2014-01-01

    Through a series of simple processes, cassava root husks were turned into a fine powder of controlled particle size (63-75 μm). FTIR spectrum demonstrated the existence of alcohol, amine and carboxylic groups; and elemental analysis confirmed the presence of elements of interest such as sulphur, nitrogen and oxygen. Cross-polarized {1H}sbnd 13C NMR technique indicated the existence of methionine and thiamine through the signals observed at 55 ppm and 54 ppm, respectively, and the point of zero charge (pHpzc) was achieved at pH 5.2. The material was applied in solid-phase extraction of Cu(II) via batch experiments. Optimum adsorption pH was found to be in range of 3-6 and in the kinetic experiment the equilibrium was attained in 1 min. The highest adsorption capacity was 0.14 mmol g-1. The adsorption data were fit to the modified Langmuir equation, and the maximum amount of metal species extracted from the solution, Ns, was determined to be ∼0.14 mmol g-1, which is an indicative that the main adsorption mechanism is through chemisorption. Under optimized conditions, the material was utilized in preconcentration experiments, which culminated in an enrichment factor of 41.3-fold. With the aid of the enrichment factor, experiments were carried out to determine the Cu(II) content in tap water and natural water. Preconcentration method was also applied to a certified reference material (1643e) and the concentration found was 23.03 ± 0.79 μg L-1, whereas the specified Cu(II) concentration was 22.7 ± 0.31 μg L-1.

  18. Productive potential of cassava plants (Manihot esculenta Crantz) propagated by leaf buds.

    PubMed

    Neves, Reizaluamar J; Diniz, Rafael P; Oliveira, Eder J DE

    2018-04-23

    New techniques of rapid multiplication of cassava (Manihot esculenta Crantz) have been developed, requiring technical support for large-scale use. This work main to evaluate the agronomic performance of plantlets obtained by leaf buds technique against stem cuttings in the field conditions. The work was conducted using the randomized block design in a factorial scheme with 3 varieties (BRS Kiriris, 98150-06, 9624-09) × 4 origins of the plantlets (conventional - stem cuttings of 20 cm length, leaf buds of the upper, middle and inferior stem part) × 2 agrochemicals (control and treated). There was a remarkable decrease in some agronomic traits that ranged from 23% (number of branches) to 62% (shoot weight) when using leaf buds plantlets. The treatment of plantlets with agrochemicals promoted significant increases in all traits, ranging from 26% (number of roots per plant) to 46% (shoot weight). The plantlets originating from leaf buds of the upper and middle parts were able to generate stem-like plants similar to stem-derived ones. Despite its lower agronomic performance under field conditions, multiplication by leaf buds may generate five times the number of propagules in comparison with the conventional multiplication, and therefore it could be a viable alternative for rapid cassava multiplication.

  19. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    PubMed

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

  20. Changes in cation concentrations in red spruce wood decayed by brown rot and white rot fungi

    Treesearch

    A. Ostrofsky; J. Jellison; K.T. Smith; W.C. Shortle

    1997-01-01

    Red spruce (Picea rubens Sarg.) wood blocks were incubated in modified soil block jars and inoculated with one of nine white rot or brown rot basidiomycetes. Concentrations of calcium, magnesium, potassium, iron, and aluminum were determined using inductively coupled plasma emission spectroscopy in wood incubated 0, 1.5, 4, and 8 months after...

  1. Root System Architecture and Abiotic Stress Tolerance: Current Knowledge in Root and Tuber Crops

    PubMed Central

    Khan, M. A.; Gemenet, Dorcus C.; Villordon, Arthur

    2016-01-01

    The challenge to produce more food for a rising global population on diminishing agricultural land is complicated by the effects of climate change on agricultural productivity. Although great progress has been made in crop improvement, so far most efforts have targeted above-ground traits. Roots are essential for plant adaptation and productivity, but are less studied due to the difficulty of observing them during the plant life cycle. Root system architecture (RSA), made up of structural features like root length, spread, number, and length of lateral roots, among others, exhibits great plasticity in response to environmental changes, and could be critical to developing crops with more efficient roots. Much of the research on root traits has thus far focused on the most common cereal crops and model plants. As cereal yields have reached their yield potential in some regions, understanding their root system may help overcome these plateaus. However, root and tuber crops (RTCs) such as potato, sweetpotato, cassava, and yam may hold more potential for providing food security in the future, and knowledge of their root system additionally focuses directly on the edible portion. Root-trait modeling for multiple stress scenarios, together with high-throughput phenotyping and genotyping techniques, robust databases, and data analytical pipelines, may provide a valuable base for a truly inclusive ‘green revolution.’ In the current review, we discuss RSA with special reference to RTCs, and how knowledge on genetics of RSA can be manipulated to improve their tolerance to abiotic stresses. PMID:27847508

  2. Cassava genome from a wild ancestor to cultivated varieties

    PubMed Central

    Wang, Wenquan; Feng, Binxiao; Xiao, Jingfa; Xia, Zhiqiang; Zhou, Xincheng; Li, Pinghua; Zhang, Weixiong; Wang, Ying; Møller, Birger Lindberg; Zhang, Peng; Luo, Ming-Cheng; Xiao, Gong; Liu, Jingxing; Yang, Jun; Chen, Songbi; Rabinowicz, Pablo D.; Chen, Xin; Zhang, Hong-Bin; Ceballos, Henan; Lou, Qunfeng; Zou, Meiling; Carvalho, Luiz J.C.B.; Zeng, Changying; Xia, Jing; Sun, Shixiang; Fu, Yuhua; Wang, Haiyan; Lu, Cheng; Ruan, Mengbin; Zhou, Shuigeng; Wu, Zhicheng; Liu, Hui; Kannangara, Rubini Maya; Jørgensen, Kirsten; Neale, Rebecca Louise; Bonde, Maya; Heinz, Nanna; Zhu, Wenli; Wang, Shujuan; Zhang, Yang; Pan, Kun; Wen, Mingfu; Ma, Ping-An; Li, Zhengxu; Hu, Meizhen; Liao, Wenbin; Hu, Wenbin; Zhang, Shengkui; Pei, Jinli; Guo, Anping; Guo, Jianchun; Zhang, Jiaming; Zhang, Zhengwen; Ye, Jianqiu; Ou, Wenjun; Ma, Yaqin; Liu, Xinyue; Tallon, Luke J.; Galens, Kevin; Ott, Sandra; Huang, Jie; Xue, Jingjing; An, Feifei; Yao, Qingqun; Lu, Xiaojing; Fregene, Martin; López-Lavalle, L. Augusto Becerra; Wu, Jiajie; You, Frank M.; Chen, Meili; Hu, Songnian; Wu, Guojiang; Zhong, Silin; Ling, Peng; Chen, Yeyuan; Wang, Qinghuang; Liu, Guodao; Liu, Bin; Li, Kaimian; Peng, Ming

    2014-01-01

    Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology. PMID:25300236

  3. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    D`Souza, T.M.; Boominathan, K.; Reddy, C.A.

    1996-10-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequences of each of the PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum,more » Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. 36 refs., 6 figs., 2 tabs.« less

  4. Straightforward rapid spectrophotometric quantification of total cyanogenic glycosides in fresh and processed cassava products.

    PubMed

    Tivana, Lucas Daniel; Da Cruz Francisco, Jose; Zelder, Felix; Bergenståhl, Bjorn; Dejmek, Petr

    2014-09-01

    In this study, we extend pioneering studies and demonstrate straightforward applicability of the corrin-based chemosensor, aquacyanocobyrinic acid (ACCA), for the instantaneous detection and rapid quantification of endogenous cyanide in fresh and processed cassava roots. Hydrolytically liberated endogenous cyanide from cyanogenic glycosides (CNp) reacts with ACCA to form dicyanocobyrinic acid (DCCA), accompanied by a change of colour from orange to violet. The method was successfully tested on various cassava samples containing between 6 and 200 mg equiv. HCN/kg as verified with isonicotinate/1,3-dimethylbarbiturate as an independent method. The affinity of ACCA sensor to cyanide is high, coordination occurs fast and the colorimetric response can therefore be instantaneously monitored with spectrophotometric methods. Direct applications of the sensor without need of extensive and laborious extraction processes are demonstrated in water-extracted samples, in acid-extracted samples, and directly on juice drops. ACCA showed high precision with a standard deviation (STDV) between 0.03 and 0.06 and high accuracy (93-96%). Overall, the ACCA procedure is straightforward, safe and easily performed. In a proof-of-concept study, rapid screening of ten samples within 20 min has been tested. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A novel, multiplexed, probe-based quantitative PCR assay for the soybean root- and stem-rot pathogen, Phytophthora sojae, utilizes its transposable element

    PubMed Central

    Haudenshield, James S.; Song, Jeong Y.; Hartman, Glen L.

    2017-01-01

    Phytophthora root rot of soybean [Glycine max (L.) Merr.] is caused by the oomycete Phytophthora sojae (Kaufm. & Gerd.). P. sojae has a narrow host range, consisting primarily of soybean, and it is a serious pathogen worldwide. It exists in root and stem tissues as mycelium, wherein it can form oospores which subsequently germinate to release motile, infectious zoospores. Molecular assays detecting DNA of P. sojae are useful in disease diagnostics, and for determining the presence of the organism in host tissues, soils, and runoff or ponded water from potentially infested fields. Such assays as published have utilized ITS sequences from the nuclear ribosomal RNA genes in conventional PCR or dye-binding quantitative PCR (Q-PCR) but are not amenable to multiplexing, and some of these assays did not utilize control strategies for type I or type II errors. In this study, we describe primers and a bifunctional probe with specificity to a gypsy-like retroelement in the P. sojae genome to create a fluorogenic 5’-exonuclease linear hydrolysis assay, with a multiplexed internal control reaction detecting an exogenous target to validate negative calls, and with uracil-deglycosylase-mediated protection against carryover contamination. The assay specifically detected 13 different P. sojae isolates, and excluded 17 other Phytophthora species along with 20 non-Phytophthora fungal and oomycete species pathogenic on soybean. A diagnostic limit of detection of 34 fg total P. sojae DNA was observed in serial dilutions, equivalent to 0.3 genome, and a practical detection sensitivity of four zoospores per sample was achieved, despite losses during DNA extraction. PMID:28441441

  6. Effects of Meloidogyne spp. and Rhizoctonia solani on the Growth of Grapevine Rootings.

    PubMed

    Walker, G E

    1997-06-01

    A disease complex involving Meloidogyne incognita and Rhizoctonia solani was associated with stunting of grapevines in a field nursery. Nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this M. incognita population, and of M. javanica and M. hapla populations, to V. vinifera cv. Colombard (susceptible) and to V. champinii cv. Ramsey (regarded locally as highly resistant). The virulence of R. solani isolates obtained from roots of diseased grapevines also was determined both alone and in combination with M. incognita. Ramsey was susceptible to M. incognita (reproduction ratio 9.8 to 18.4 in a shadehouse and heated glasshouse, respectively) but was resistant to M. javanica and M. hapla. Colombard was susceptible to M. incognita (reproduction ratio 24.3 and 41.3, respectively) and M. javanica. Shoot growth was suppressed (by 35%) by M. incognita and, to a lesser extent, by M. hapla. Colombard roots were more severely galled than Ramsey roots by all three species, and nematode reproduction was higher on Colombard. Isolates of R. solani assigned to putative anastomosis groups 2-1 and 4, and an unidentified isolate, colonized and induced rotting of grapevine roots. Ramsey was more susceptible to root rotting than Colombard. Shoot growth was inhibited by up to 15% by several AG 4 isolates and by 20% by the AG 2-1 isolate. AG 4 isolates varied in their virulence. Root rotting was higher when grapevines were inoculated with both M. incognita and R. solani and was highest when nematode inoculation preceded the fungus. Shoot weights were lower when vines were inoculated with the nematode 13 days before the fungus compared with inoculation with both the nematode and the fungus on the same day. It was concluded that both the M. incognita population and some R. solani isolates were virulent against both Colombard and Ramsey, and that measures to prevent spread in nursery stock were

  7. Quantitative trait loci and candidate genes associated with starch pasting viscosity characteristics in cassava (Manihot esculenta Crantz).

    PubMed

    Thanyasiriwat, T; Sraphet, S; Whankaew, S; Boonseng, O; Bao, J; Lightfoot, D A; Tangphatsornruang, S; Triwitayakorn, K

    2014-01-01

    Starch pasting viscosity is an important quality trait in cassava (Manihot esculenta Crantz) cultivars. The aim here was to identify loci and candidate genes associated with the starch pasting viscosity. Quantitative trait loci (QTL) mapping for seven pasting viscosity parameters was carried out using 100 lines of an F1 mapping population from a cross between two cassava cultivars Huay Bong 60 and Hanatee. Starch samples were obtained from roots of cassava grown in 2008 and 2009 at Rayong, and in 2009 at Lop Buri province, Thailand. The traits showed continuous distribution among the F1 progeny with transgressive variation. Fifteen QTL were identified from mean trait data, with Logarithm of Odds (LOD) values from 2.77-13.01 and phenotype variations explained (PVE) from10.0-48.4%. In addition, 48 QTL were identified in separate environments. The LOD values ranged from 2.55-8.68 and explained 6.6-43.7% of phenotype variation. The loci were located on 19 linkage groups. The most important QTL for pasting temperature (PT) (qPT.1LG1) from mean trait values showed largest effect with highest LOD value (13.01) and PVE (48.4%). The QTL co-localised with PT and pasting time (PTi) loci that were identified in separate environments. Candidate genes were identified within the QTL peak regions. However, the major genes of interest, encoding the family of glycosyl or glucosyl transferases and hydrolases, were located at the periphery of QTL peaks. The loci identified could be effectively applied in breeding programmes to improve cassava starch quality. Alleles of candidate genes should be further studied in order to better understand their effects on starch quality traits. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. Molecular cloning, subcellular localization and characterization of two adenylate kinases from cassava, Manihot esculenta Crantz cv. KU50.

    PubMed

    Boonrueng, Channarong; Tangpranomkorn, Surachat; Yazhisai, Uthaman; Sirikantaramas, Supaart

    2016-10-01

    Adenylate kinase (ADK) is a phosphotransferase that plays an important role in cellular energy homeostasis. Many isozymes located in different subcellular compartments have been reported. In this study, we focus on the characterization of cassava (Manihot esculenta) ADKs. We found 15 ADKs that are publicly available in the African cassava genome database. We cloned two ADKs, namely MeADK1 and MeADK2, which are phylogenetically grouped together with the plastidial ADK in potato. Both MeADK1 and MeADK2 showed 66% identity in the amino acid sequences with plastidial ADK in potato. However, we demonstrated that they are localized to mitochondria using GFP fusions of MeADK1 and MeADK2. The Escherichia coli-produced recombinant MeADK1 and MeADK2 preferred forward reactions that produce ATP. They exhibited similar specific activities. The semi-quantitative RT-PCR analysis showed that MeADK1 and MeADK2 in 2-month-old leaves have similar expression patterns under a diurnal light-dark cycle. However, MeADK2 transcripts were expressed at much higher levels than MeADK1 in 5-month-old leaves and roots. Thus, we conclude that MeADK2 might play a vital role in energy homeostasis in cassava mitochondria. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Induction and identification of a small-granule, high-amylose mutant in cassava (Manihot esculenta Crantz).

    PubMed

    Ceballos, Hernán; Sánchez, Teresa; Denyer, Kay; Tofiño, Adriana P; Rosero, Elvia A; Dufour, Dominique; Smith, Alison; Morante, Nelson; Pérez, Juan C; Fahy, Brendan

    2008-08-27

    Only two mutations have been described in the literature, so far, regarding starch and root quality traits in cassava. This article reports on an induced mutation in this crop, first identified in 2006. Botanical seed from five different cassava families were irradiated with gamma rays. Seed was germinated, transplanted to the field (M1 plants), and self-pollinated to produce the M2 generation. Abnormal types regarding starch granule morphology were identified during the single plant evaluation of M2 genotypes. To confirm these characteristics, selected genotypes were cloned and a second evaluation, based on cloned plants obtained from vegetative multiplication, was completed in September 2007. Two M2 genotypes presented small starch granules, but only one could be fully characterized, presenting a granule size of 5.80 +/- 0.33 microm compared with three commercial clones with granule sizes ranging from 13.97 +/- 0.12 to 18.73 +/- 0.10 microm and higher-than-normal amylose content (up to 30.1% in cloned plants harvested in 2007, as compared with the typical values for "normal" cassava starch of around 19.8%). The gels produced by the starch of these plants did not show any viscosity when analyzed with the rapid viscoanalyzers (5% suspension), and the gels had low clarity. Low viscosity could be observed at higher concentrations (8 or 10% suspensions). Preliminary results suggest that the mutation may be due to a lesion in a gene encoding one of the isoforms of isoamylase (probably isa1 or isa2).

  10. Conversion of cassava wastes for biofertilizer production using phosphate solubilizing fungi.

    PubMed

    Ogbo, Frank C

    2010-06-01

    Two fungi characterized as Aspergillus fumigatus and Aspergillus niger, isolated from decaying cassava peels were used to convert cassava wastes by the semi-solid fermentation technique to phosphate biofertilizer. The isolates solubilized Ca(3)(PO(4))(2), AlPO(4) and FePO(4) in liquid Pikovskaya medium, a process that was accompanied by acid production. Medium for the SSF fermentation was composed of 1% raw cassava starch and 3% poultry droppings as nutrients and 96% ground (0.5-1.5mm) dried cassava peels as carrier material. During the 14days fermentation, both test organisms increased in biomass in this medium as indicated by increases in phosphatase activity and drop in pH. Ground cassava peels satisfied many properties required of carrier material particularly in respect of the organisms under study. Biofertilizer produced using A. niger significantly (p<.05) improved the growth of pigeon pea [Cajanus cajan (L.) Millsp.] in pot experiments but product made with A. fumigatus did not. Copyright 2009 Elsevier Ltd. All rights reserved.

  11. Combination of cassava flour cyanide and urinary thiocyanate measurements of school children in Mozambique.

    PubMed

    Paula Cardoso, A; Ernesto, Mario; Nicala, Domingos; Mirione, Estevao; Chavane, Leonardo; N'zwalo, Hipolito; Chikumba, Sergio; Cliff, Julie; Paulo Mabota, A; Rezaul Haque, M; Howard Bradbury, J

    2004-05-01

    The maximum daily cassava flour intake of children may be calculated from determination of the total cyanide content of cassava flour and urinary thiocyanate levels of school children in samples collected at the same time and place. Four sites, two with and two without recent konzo cases, were chosen for study. In two sites with recent konzo cases, 84% and 93% of school children consumed cassava the previous day, and the calculated maximum daily consumption of cassava was over 700 g. In two sites without recent konzo cases, about 50% of school children consumed cassava the previous day and the calculated daily consumption of cassava flour was less than 150 g. By measurements of cyanide in flour and urinary thiocyanate we are therefore able to distinguish between communities whose diet is almost totally reliant on cassava, and who are therefore susceptible to konzo, and those who have a broader diet and are free from konzo. In another calculation it is shown that 4-23% of the essential S-containing amino acids in the cassava flour consumed by children is used up to detoxify and flour cyanide to thiocyanate. This depletion of methionine and cystine may leads to protein deficiency and may contribute to onset of konzo.

  12. Responses of tropical root crops to climate change: implications for Pacific food security

    NASA Astrophysics Data System (ADS)

    Gleadow, R.; Webber, B.; Macness, N.; Lisson, S.; Nauluvula, P.; Hargraves, J.; Crimp, S. J.

    2013-12-01

    Cassava and taro are an important source of calories in many parts of the developing world and hold much promise for meeting the need for food security in equatorial regions. Communities in the Pacific Island countries reliant on agriculture-based livelihood systems have been identified as particularly at risk from climate change, due to likely increases in crop failure, new patterns of pests and diseases, lack of appropriate seed and plant material, loss of livestock and potential loss of arable land. Recent shortfalls in agricultural production resulting from changing export markets, commodity prices, climatic variation, and population growth and urbanisation, have contributed further to regional food insecurity concerns. Cassava and taro contain herbivore defense chemicals that are detrimental to human health (cyanogenic glucosides and calcium oxalate). Unprocessed cassava can cause acute cyanide intoxication, paralysis and even death, especially during droughts. A number of activities are already underway in the Pacific region to identify ways to ameliorate existing climate risk and enhance current agricultural production. Whilst these activities are important to ensure long-term agricultural sustainability, there remains a significant degree of uncertainty as to how effective these strategies may be in the face of a changing and increasingly variable future climate. We present our current understanding of the impact of climate change on key Pacific production systems - specifically those based on the staple root crops, taro and cassava. This includes (1) Our understanding of the responses of cassava and taro crops to existing environmental drivers (climate, soil and nutrient interactions); (2) The responses of cassava and taro crops to enhanced CO2 conditions; and (3) Efforts to model productivity responses (within the APSIM framework) and results for locations in the Pacific.

  13. Study on the preparation process of cross-linked porous cassava starch

    NASA Astrophysics Data System (ADS)

    Yin, Xiulian; You, Qinghong; Wan, Miaomiao; Zhang, Xuejuan; Dai, Chunhua

    2017-04-01

    Using cassava starch as raw material, preparation process of porous cross-linked cassava starch was studied. Using TSTP as cross-linking agents, Orthogonal design was applied for the optimization of cross-linked porous starch preparation process. The results showed that the opitmal conditions of cross-linked porous cassava starch were as follows: reaction temperature 45°C, reaction time 20 h, 1% of the amount of the enzyme, the enzyme ratio of 1:5, pH 5.50, substrate concentration of 40%.

  14. Transcriptional response to petiole heat girdling in cassava.

    PubMed

    Zhang, Yang; Ding, Zehong; Ma, Fangfang; Chauhan, Raj Deepika; Allen, Doug K; Brutnell, Thomas P; Wang, Wenquan; Peng, Ming; Li, Pinghua

    2015-02-12

    To examine the interactions of starch and sugar metabolism on photosynthesis in cassava, a heat-girdling treatment was applied to petioles of cassava leaves at the end of the light cycle to inhibit starch remobilization during the night. The inhibition of starch remobilization caused significant starch accumulation at the beginning of the light cycle, inhibited photosynthesis, and affected intracellular sugar levels. RNA-seq analysis of heat-treated and control plants revealed significantly decreased expression of genes related to photosynthesis, as well as N-metabolism and chlorophyll biosynthesis. However, expression of genes encoding TCA cycle enzymes and mitochondria electron transport components, and flavonoid biosynthetic pathway enzymes were induced. These studies reveal a dynamic transcriptional response to perturbation of sink demand in a single leaf, and provide useful information for understanding the regulations of cassava under sink or source limitation.

  15. Transcriptional response to petiole heat girdling in cassava

    PubMed Central

    Zhang, Yang; Ding, Zehong; Ma, Fangfang; Chauhan, Raj Deepika; Allen, Doug K.; Brutnell, Thomas P.; Wang, Wenquan; Peng, Ming; Li, Pinghua

    2015-01-01

    To examine the interactions of starch and sugar metabolism on photosynthesis in cassava, a heat-girdling treatment was applied to petioles of cassava leaves at the end of the light cycle to inhibit starch remobilization during the night. The inhibition of starch remobilization caused significant starch accumulation at the beginning of the light cycle, inhibited photosynthesis, and affected intracellular sugar levels. RNA-seq analysis of heat-treated and control plants revealed significantly decreased expression of genes related to photosynthesis, as well as N-metabolism and chlorophyll biosynthesis. However, expression of genes encoding TCA cycle enzymes and mitochondria electron transport components, and flavonoid biosynthetic pathway enzymes were induced. These studies reveal a dynamic transcriptional response to perturbation of sink demand in a single leaf, and provide useful information for understanding the regulations of cassava under sink or source limitation. PMID:25672661

  16. Energy Value of Cassava Products in Broiler Chicken Diets with or without Enzyme Supplementation

    PubMed Central

    Bhuiyan, M. M.; Iji, P. A.

    2015-01-01

    This study investigated the metabolizable energy (ME) intake, net energy of production (NEp), heat production (HP), efficiencies of ME use for energy, lipid and protein retention as well as the performance of broiler chickens fed diets based on cassava chips or pellets with or without supplementation with an enzyme product containing xylanase, amylase, protease and phytase. The two products, cassava chips and pellets, were analysed for nutrient composition prior to feed formulation. The cassava chips and pellets contained 2.2% and 2.1% crude protein; 1.2% and 1.5% crude fat; and 75.1% and 67.8% starch, respectively. Lysine and methionine were 0.077%, 0.075%, and 0.017%, 0.020% protein material, respectively, while calculated ME was 12.6 and 11.7 MJ/kg, respectively. Feed intake to day 21 was lower (p<0.01) on the diet containing cassava chips compared to diets with cassava pellets. Enzyme supplementation increased (p<0.01) feed intake on all diets. Live weight at day 21 was significantly (p<0.01) reduced on the diet based on cassava chips compared to pellets, but an improvement (p<0.01) was noticed with the enzyme supplementation. Metabolizable energy intake was reduced (p<0.01) by both cassava chips and pellets, but was increased (p<0.01) on all diets by enzyme supplementation. The NEp was higher (p<0.01) in the maize-based diets than the diets containing cassava. Enzyme supplementation improved (p<0.01) NEp in all the diets. Heat production was highest (p<0.01) on diets containing cassava pellets than on cassava chips. It is possible to use cassava pellets in diets for broiler chickens at a level close to 50% of the diet to reduce cost of production, and the nutritive value of such diets can be improved through supplementation of enzyme products containing carbohydrases, protease, and phytase. PMID:26194227

  17. Correlation of Chemical Compositions of Cassava Varieties to Their Resistance to Prostephanus truncatus Horn (Coleoptera: Bostrichidae)

    PubMed Central

    Osipitan, Adebola A.; Sangowusi, Victoria T.; Lawal, Omoniyi I.; Popoola, Kehinde O.

    2015-01-01

    The preference of cassava as a major host by Prostephanus truncatus Horn is a major constraint to ample production of cassava, Manihot esculenta Crantz and storage. This study analyzed the nutritional and secondary metabolite compositions in 15 cassava varieties, evaluated levels of damage and reproduction by P. truncatus, and assessed their resistance to attack. One hundred grams of dried cassava chips in 250-ml Kilner jars were infested with 10 adult larger grain borerof 0–10 days old and held for 3 months. The nutritional and secondary metabolites compositions of the dry cassava chips were determined using the method of Association of Analytical Chemists . Chip perforation rates in the cassava varieties ranged from 17.7 to 71.6%. The weight of cassava powder varied by about threefold. The final number of larger grain borer in the cassava varieties varied by about sixfold with 63 in 01/0040 and 379 in 01/1368. Hydrocyanic acid content content varied by over 10-fold and correlated negatively with number of larger grain borer. Flavonoid content varied by ∼10%. Tannins and saponin content of the cassava negatively correlated with number of adult P. truncatus. The cassava varieties 95/0166, 92/0326, 01/0040, 05/0024, and 34 91934 had selection index <0.8 and were classified as resistant to larger grain borer damage, while others with selection index >0.8 were classified as susceptible. The resistance to high damage in the resistant varieties was conferred by secondary metabolites such as tannins, saponins, alkaloids, and hydrocyanic acid content. The genetic variation in cassava varieties could be explored to breed resistant cassava varieties for use in larger grain borer-endemic areas. PMID:25700536

  18. Correlation of concentration of modified cassava flour for banana fritter flour using simple linear regression

    NASA Astrophysics Data System (ADS)

    Herminiati, A.; Rahman, T.; Turmala, E.; Fitriany, C. G.

    2017-12-01

    The purpose of this study was to determine the correlation of different concentrations of modified cassava flour that was processed for banana fritter flour. The research method consists of two stages: (1) to determine the different types of flour: cassava flour, modified cassava flour-A (using the method of the lactid acid bacteria), and modified cassava flour-B (using the method of the autoclaving cooling cycle), then conducted on organoleptic test and physicochemical analysis; (2) to determine the correlation of concentration of modified cassava flour for banana fritter flour, by design was used simple linear regression. The factors were used different concentrations of modified cassava flour-B (y1) 40%, (y2) 50%, and (y3) 60%. The response in the study includes physical analysis (whiteness of flour, water holding capacity-WHC, oil holding capacity-OHC), chemical analysis (moisture content, ash content, crude fiber content, starch content), and organoleptic (color, aroma, taste, texture). The results showed that the type of flour selected from the organoleptic test was modified cassava flour-B. Analysis results of modified cassava flour-B component containing whiteness of flour 60.42%; WHC 41.17%; OHC 21.15%; moisture content 4.4%; ash content 1.75%; crude fiber content 1.86%; starch content 67.31%. The different concentrations of modified cassava flour-B with the results of the analysis provides correlation to the whiteness of flour, WHC, OHC, moisture content, ash content, crude fiber content, and starch content. The different concentrations of modified cassava flour-B does not affect the color, aroma, taste, and texture.

  19. Correlation of chemical compositions of cassava varieties to their resistance to Prostephanus truncatus Horn (Coleoptera: Bostrichidae).

    PubMed

    Osipitan, Adebola A; Sangowusi, Victoria T; Lawal, Omoniyi I; Popoola, Kehinde O

    2015-01-01

    The preference of cassava as a major host by Prostephanus truncatus Horn is a major constraint to ample production of cassava, Manihot esculenta Crantz and storage. This study analyzed the nutritional and secondary metabolite compositions in 15 cassava varieties, evaluated levels of damage and reproduction by P. truncatus, and assessed their resistance to attack. One hundred grams of dried cassava chips in 250-ml Kilner jars were infested with 10 adult larger grain borerof 0-10 days old and held for 3 months. The nutritional and secondary metabolites compositions of the dry cassava chips were determined using the method of Association of Analytical Chemists . Chip perforation rates in the cassava varieties ranged from 17.7 to 71.6%. The weight of cassava powder varied by about threefold. The final number of larger grain borer in the cassava varieties varied by about sixfold with 63 in 01/0040 and 379 in 01/1368. Hydrocyanic acid content content varied by over 10-fold and correlated negatively with number of larger grain borer. Flavonoid content varied by ∼10%. Tannins and saponin content of the cassava negatively correlated with number of adult P. truncatus. The cassava varieties 95/0166, 92/0326, 01/0040, 05/0024, and 34 91934 had selection index <0.8 and were classified as resistant to larger grain borer damage, while others with selection index >0.8 were classified as susceptible. The resistance to high damage in the resistant varieties was conferred by secondary metabolites such as tannins, saponins, alkaloids, and hydrocyanic acid content. The genetic variation in cassava varieties could be explored to breed resistant cassava varieties for use in larger grain borer-endemic areas. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  20. Konzo: from poverty, cassava, and cyanogen intake to toxico-nutritional neurological disease.

    PubMed

    Nzwalo, Hipólito; Cliff, Julie

    2011-06-01

    Konzo is a distinct neurological entity with selective upper motor neuron damage, characterized by an abrupt onset of an irreversible, non-progressive, and symmetrical spastic para/tetraparesis. Despite its severity, konzo remains a neglected disease. The disease is associated with high dietary cyanogen consumption from insufficiently processed roots of bitter cassava combined with a protein-deficient diet. Epidemics occur when these conditions coincide at times of severe food shortage. Up to 1993, outbreaks in poor rural areas in Africa contributed to more than 3,700 cases of konzo. The number of affected people is underestimated. From unofficial reports, the number of cases was estimated to be at least 100,000 in 2000, in contrast to the 6,788 cases reported up to 2009 from published papers.

  1. Aggressive root pathogen Phellinus noxius and implications for western Pacific Islands

    Treesearch

    Sara M. Ashiglar; Phil G. Cannon; Ned B. Klopfenstein

    2015-01-01

    Phellinus noxius is an aggressive root rot pathogen affecting tropical and subtropical forests. Causing much damage in tropical Asia, Africa, Taiwan, Japan and the Pacific Islands, its wide host range encompasses more than 200 plant species representing 59 families (Ann et al. 2002). It can devastate agricultural plantations of tea, rubber, cocoa, avocados,...

  2. Race Characterization of Phytophthora root rot on Capsicum in Taiwan as a Basis for Anticipatory Resistance Breeding.

    PubMed

    Barchenger, Derek W; Sheu, Zong-Ming; Kumar, Sanjeet; Lin, Shih-Wen; Burlakoti, Rishi R; Bosland, Paul W

    2018-02-27

    Peppers (Capsicum sp.) are an increasingly important crop because of their use as a vegetable, spice, and food colorant. The oomycete Phytophthora capsici is one of the most devastating pathogens to pepper production worldwide, causing more than $100 million in losses annually. Developing cultivars resistant to P. capsici is challenging because of the many physiological races that exist and new races that are continuously evolving. This problem is confounded by the lack of a universal system of race characterization. As a basis to develop a global anticipatory breeding program, New Mexico Recombinant Inbred Lines (NMRILs) functioned as a host differential for Phytophthora root rot to characterize the race structure of P. capsici populations in Taiwan. Using the NMRILs, 24 new races were identified, illustrating the utility and usefulness of the NMRILs for anticipatory breeding. Virulence of P. capsici was observed to be geographically specific and in two virulence clusters. Interestingly, all but two isolates collected in 2016 were the A2 mating type, which is a shift from the predominantly A1 mating type isolates collected prior to 2008. The NMRILs host differential provides an approach for scientists to work together on a global scale when breeding for resistance as well as on a local level for regional gene deployment. Additionally, we propose that the current race numbering system, which has no biological meaning, be supplemented with the virulence phenotype, based on the susceptible NMRILs to a given isolate. This work provides insights into the population dynamics of P. capsici and interactions within the highly complex Capsicum-Phytophthora pathosystem, and offers a basis for similar research in other crops.

  3. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    PubMed

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  4. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan

    PubMed Central

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J.; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands. PMID:26513585

  5. Long-term ingestion of cassava (tapioca) does not produce diabetes or pancreatitis in the rat model.

    PubMed

    Mathangi, D C; Deepa, R; Mohan, V; Govindarajan, M; Namasivayam, A

    2000-06-01

    Cassava (tapioca, manihot) is consumed as a staple food in some developing countries. The intake of cassava has been linked to several diseases including fibrocalculous pancreatic diabetes (tropical calcific pancreatitis). There are few long-term studies on the effect of cassava ingestion on the pancreas in animal models. This article reports on the long-term (up to 1 yr) effects of cassava in the rat model. We found that cassava did not produce diabetes in the rat even after a year of cassava feeding. There were transient changes in serum insulin and lipase levels, but the significance of these findings are not clear. There was no histopathological evidence of either acute or chronic pancreatitis, but there were changes of toxic hepatitis in the liver. In conclusion, chronic cassava ingestion up to a year does not lead to either diabetes or chronic pancreatitis in the rat model.

  6. Process for protein enrichment of cassava by solid substrate fermentation in rural conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Daubresse, P.; Ntibashirwa, S.; Gheysen, A.

    1987-06-01

    An artisanal static process for protein enrichment of cassava by solid-state fermentation, developed in laboratory and tested on pilot units in Burundi (Central Africa), provides enriched cassava containing 10.7% of dry matter protein versus 1% before fermentation. Cassava chips, processed into granules of 2-4-mm diameter, are moistened (40% water content) and steamed. After cooling to 40 degrees C, cassava is mixed with a nutritive solution containing the inoculum (Rhizopus oryzae, strain MUCL 28627) and providing the following per 100 g dry matter: 3.4 g urea, 1.5 g KH/sub 2/PO/sub 4/, O.8 g MgSO/sub 4/.7H/sub 2/O, and 22.7 g citric acid.more » For the fermentation, cassava, with circa 60% moisture content, is spread in a thin layer (2-3 cm thick) on perforated trays and slid into an aerated humidified enclosure. The incubation lasts more or less 65 hours. The production of protein enriched cassava is 3.26 kg dry matter/square m tray. The effects of the variation of the nutritive solution composition and the inoculum conservation period on the protein production are equally discussed. (Refs. 37).« less

  7. Preparation and Characterization of Cellulose and Nanocellulose from Agro-industrial Waste - Cassava Peel

    NASA Astrophysics Data System (ADS)

    Widiarto, S.; Yuwono, S. D.; Rochliadi, A.; Arcana, I. M.

    2017-02-01

    Cassava peel is an agro-industrial waste which is available in huge quantities in Lampung Province of Indonesia. This work was conducted to evaluate the potential of cassava peel as a source of cellulose and nanocellulose. Cellulose was extracted from cassava peel by using different chemical treatment, and the nanocellulose was prepared by hydrolysis with the use of sulfuric acid. The best methods of cellulose extraction from cassava peels are using alkali treatment followed by a bleaching process. The cellulose yield from this methods was 17.8% of dry base cassava peel, while the yield from nitric and sulfuric methods were about 10.78% and 10.32% of dry base cassava peel respectively. The hydrolysis was performed at the temperature of 50 °C for 2 hours. The intermediate reaction product obtained after each stage of the treatments was characterized. Fourier transform infrared spectroscopy showed the removal of non-cellulosic constituent. X-ray Diffraction (XRD) analysis revealed that the crystallinity of cellulose increased after hydrolysis. Morphological investigation was performed using Scanning Electron Microscopy (SEM). The size of particle was confirmed by Particle Size Analyzer (PSA) and Transmission Electron Microscopy (TEM).

  8. Effect of storage on the chemical composition, microbiological load, and sensory properties of cassava starch-based custard powder

    PubMed Central

    Awoyale, Wasiu; Sanni, Lateef O; Shittu, Taofik A; Adegunwa, Mojisola O

    2015-01-01

    The effect of storage on the chemical, microbiological, and sensory properties of cassava starch-based custard powder (CbCP) blends as mixture of yellow-fleshed cassava root starch (YfCRS) (90–98%) and whole egg powder (WEP) (2–10%) was investigated. These were prepared using central composite rotatable design, and separately packaged in polyvinyl chloride plastic can and stored in storage box (30 ± 2°C). The chemical and microbiological analyses of the stored CbCP were evaluated at 3 weeks intervals, while the sensory property was determined at 6 weeks interval for 24 weeks. The result showed that the protein, fat, and the total-β-carotene contents of the CbCP decreased significantly (P ≤ 0.001) after storage while moisture content and microbiological load increased. All the CbCP sensory attributes were accepted at the end of storage, except taste and color. The CbCP gruel prepared from 94% YfCRS: 0.34% WEP and 90% YfCRS: 2% WEP blends were the most acceptable after storage. PMID:26405528

  9. Effect of storage on the chemical composition, microbiological load, and sensory properties of cassava starch-based custard powder.

    PubMed

    Awoyale, Wasiu; Sanni, Lateef O; Shittu, Taofik A; Adegunwa, Mojisola O

    2015-09-01

    The effect of storage on the chemical, microbiological, and sensory properties of cassava starch-based custard powder (CbCP) blends as mixture of yellow-fleshed cassava root starch (YfCRS) (90-98%) and whole egg powder (WEP) (2-10%) was investigated. These were prepared using central composite rotatable design, and separately packaged in polyvinyl chloride plastic can and stored in storage box (30 ± 2°C). The chemical and microbiological analyses of the stored CbCP were evaluated at 3 weeks intervals, while the sensory property was determined at 6 weeks interval for 24 weeks. The result showed that the protein, fat, and the total-β-carotene contents of the CbCP decreased significantly (P ≤ 0.001) after storage while moisture content and microbiological load increased. All the CbCP sensory attributes were accepted at the end of storage, except taste and color. The CbCP gruel prepared from 94% YfCRS: 0.34% WEP and 90% YfCRS: 2% WEP blends were the most acceptable after storage.

  10. Functional characterization of WHY-WRKY75 transcriptional module in plant response to cassava bacterial blight.

    PubMed

    Liu, Wen; Yan, Yu; Zeng, Hongqiu; Li, Xiaolin; Wei, Yunxie; Liu, Guoyin; He, Chaozu; Shi, Haitao

    2018-05-19

    Cassava is a major food crop in tropical areas, but its productivity and quality are seriously limited by cassava bacterial blight. So far, the key factors regulating cassava immune response remain elusive. In this study, we identified three cassava Whirly genes (MeWHYs) in cassava variety of South China 124 (SC124), and explored the possible roles and utilization of MeWHYs in cassava disease resistance. Gene expression analysis revealed that the transcripts of three MeWHYs were commonly regulated by the highly conserved N-terminal epitope of f lagellin (flg22) and Xanthomonas axonopodis pv. manihotis Hainan (Xam HN) treatments. Overexpression of MeWHYs improved plant disease resistance against X. axonopodis pv. manihotis, while MeWHYs-silenced cassava plants by virus-induced gene silencing exhibited decreased disease resistance. Notably, MeWRKY75 physically interacted with three MeWHYs in yeast and in planta, and served as a transcriptional activator of MeWHY3. Moreover, the physical interaction between MeWHYs and MeWRKY75 promoted the transcriptional activities of each other. Consistently, MeWRKY75 also positively regulated disease resistance against cassava bacterial blight. Taken together, our observations suggested that MeWRKY75 and MeWHYs confer improved disease resistance against cassava bacterial blight through forming an interacting complex of MeWRKY75-MeWHY1/2/3 and transcriptional module of MeWRKY75-MeWHY3. This study facilitates our understanding of the positive effect of the MeWRKY75-MeWHY3 transcriptional module in plant disease resistance.

  11. Testing and implementing methods for managing Phytophthora root diseases in California native habitats and restoration sites

    Treesearch

    Tedmund J. Swiecki; Elizabeth A. Bernhardt

    2017-01-01

    Over the past 14 years, a variety of native plant communities in northern California have been identified where introduced root-rotting Phytophthora species, most notably Phytophthora cinnamomi, P. cambivora, and P. cactorum, are causing decline and mortality of...

  12. Effect of carboxymethyl cellulose concentration on physical properties of biodegradable cassava starch-based films

    PubMed Central

    2011-01-01

    Background Cassava starch, the economically important agricultural commodity in Thailand, can readily be cast into films. However, the cassava starch film is brittle and weak, leading to inadequate mechanical properties. The properties of starch film can be improved by adding plasticizers and blending with the other biopolymers. Results Cassava starch (5%w/v) based films plasticized with glycerol (30 g/100 g starch) were characterized with respect to the effect of carboxymethyl cellulose (CMC) concentrations (0, 10, 20, 30 and 40%w/w total solid) and relative humidity (34 and 54%RH) on the mechanical properties of the films. Additionally, intermolecular interactions were determined by Fourier transform infrared spectroscopy (FT-IR), melting temperature by differential scanning calorimetry (DSC), and morphology by scanning electron microscopy (SEM). Water solubility of the films was also determined. Increasing concentration of CMC increased tensile strength, reduced elongation at break, and decreased water solubility of the blended films. FT-IR spectra indicated intermolecular interactions between cassava starch and CMC in blended films by shifting of carboxyl (C = O) and OH groups. DSC thermograms and SEM micrographs confirmed homogeneity of cassava starch-CMC films. Conclusion The addition of CMC to the cassava starch films increased tensile strength and reduced elongation at break of the blended films. This was ascribed to the good interaction between cassava starch and CMC. Cassava starch-CMC composite films have the potential to replace conventional packaging, and the films developed in this work are suggested to be suitable for low moisture food and pharmaceutical products. PMID:21306655

  13. Genome-wide association and prediction analysis in African cassava (Manihot esculenta) reveals the genetic architecture of resistance to cassava mosaic disease and prospects for rapid genetic improvement

    USDA-ARS?s Scientific Manuscript database

    Cassava (Manihot esculenta) is a crucial, under-researched crop feeding millions worldwide, especially in Africa. Cassava mosaic disease (CMD) has plagued production in Africa for over a century. Bi-parental mapping studies suggest primarily a single major gene mediates resistance. To be certain and...

  14. Alcoholic fermentation of raw cassava starch by Rhizopus koji without cooking

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fuijo, Y.; Suyanadona, P.; Attasampunna, P.

    Using only wheat bran koji from the Rhizopus strain, raw cassava starch and cassava pellets converted reasonably well to alcohol (ethanol) without cooking at 35 degrees C and pH 4.5-5.0. When the initial broth contained 30 g raw cassava starch, 10 g Rhizopus species koji, and 100 mL tap water, 12.1 g of alcohol was recovered by final distillation from fermented broth. In this case, 12.1 g alcohol corresponds to an 85.5% conversion rate based on the theoretical value of the starch content. When the initial broth contained 40 g cassava starch, 14.1 g of alcohol was recovered, where 14.1more » g corresponds to a 74.5% conversion rate. The alcoholic fermentation process described in the present work is considered more effective and reasonable than the process using raw starch without cooking reported until now, since the new process makes it unnecessary to add yeast cells and glucoamylase preparation. (Refs. 15).« less

  15. Application of thermophilic enzymes and water jet system to cassava pulp.

    PubMed

    Chaikaew, Siriporn; Maeno, Yuka; Visessanguan, Wonnop; Ogura, Kota; Sugino, Gaku; Lee, Seung-Hwan; Ishikawa, Kazuhiko

    2012-12-01

    Co-production of fermentable sugars and nanofibrillated cellulose from cassava pulp was achieved by the combination of thermophilic enzymes (endoglucanase, β-glucosidase, and α-amylase) and a new atomization system (Star Burst System; SBS), which employs opposing water jets. The SBS represents a key technology for providing cellulose nanofibers and improving the enzymatic saccharification of cassava pulp. Depending on the enzymes used, the production of glucose from cassava pulp treated with the SBS was 1.2- to 2.5-fold higher than that from pulp not treated with the SBS. Nanofibrillated cellulose with the gel-like property in suspension was produced (yield was over 90%) by α-amylase treatment, which completely released trapped starch granules from the fibrous cell wall structure of cassava pulp pretreated with the SBS. The SBS provides an environmentally low-impact pretreatment system for processing biomass material into value-added products. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. A genome scan for quantitative trait loci affecting cyanogenic potential of cassava root in an outbred population.

    PubMed

    Whankaew, Sukhuman; Poopear, Supannee; Kanjanawattanawong, Supanath; Tangphatsornruang, Sithichoke; Boonseng, Opas; Lightfoot, David A; Triwitayakorn, Kanokporn

    2011-05-25

    Cassava (Manihot esculenta Crantz) can produce cyanide, a toxic compound, without self-injury. That ability was called the cyanogenic potential (CN). This project aimed to identify quantitative trait loci (QTL) associated with the CN in an outbred population derived from 'Hanatee' × 'Huay Bong 60', two contrasting cultivars. CN was evaluated in 2008 and in 2009 at Rayong province, and in 2009 at Lop Buri province, Thailand. CN was measured using a picrate paper kit. QTL analysis affecting CN was performed with 303 SSR markers. The phenotypic values showed continuous variation with transgressive segregation events with more (115 ppm) and less CN (15 ppm) than either parent ('Hanatee' had 33 ppm and 'Huay Bong 60' had 95 ppm). The linkage map consisted of 303 SSR markers, on 27 linkage groups with a map that encompassed 1,328 cM. The average marker interval was 5.8 cM. Five QTL underlying CN were detected. CN08R1from 2008 at Rayong, CN09R1and CN09R2 from 2009 at Rayong, and CN09L1 and CN09L2 from 2009 at Lop Buri were mapped on linkage group 2, 5, 10 and 11, respectively. Among all the identified QTL, CN09R1 was the most significantly associated with the CN trait with LOD score 5.75 and explained the greatest percentage of phenotypic variation (%Expl.) of 26%. Five new QTL affecting CN were successfully identified from 4 linkage groups. Discovery of these QTL can provide useful markers to assist in cassava breeding and studying genes affecting the trait.

  17. A genome scan for quantitative trait loci affecting cyanogenic potential of cassava root in an outbred population

    PubMed Central

    2011-01-01

    Background Cassava (Manihot esculenta Crantz) can produce cyanide, a toxic compound, without self-injury. That ability was called the cyanogenic potential (CN). This project aimed to identify quantitative trait loci (QTL) associated with the CN in an outbred population derived from 'Hanatee' × 'Huay Bong 60', two contrasting cultivars. CN was evaluated in 2008 and in 2009 at Rayong province, and in 2009 at Lop Buri province, Thailand. CN was measured using a picrate paper kit. QTL analysis affecting CN was performed with 303 SSR markers. Results The phenotypic values showed continuous variation with transgressive segregation events with more (115 ppm) and less CN (15 ppm) than either parent ('Hanatee' had 33 ppm and 'Huay Bong 60' had 95 ppm). The linkage map consisted of 303 SSR markers, on 27 linkage groups with a map that encompassed 1,328 cM. The average marker interval was 5.8 cM. Five QTL underlying CN were detected. CN08R1from 2008 at Rayong, CN09R1and CN09R2 from 2009 at Rayong, and CN09L1 and CN09L2 from 2009 at Lop Buri were mapped on linkage group 2, 5, 10 and 11, respectively. Among all the identified QTL, CN09R1 was the most significantly associated with the CN trait with LOD score 5.75 and explained the greatest percentage of phenotypic variation (%Expl.) of 26%. Conclusions Five new QTL affecting CN were successfully identified from 4 linkage groups. Discovery of these QTL can provide useful markers to assist in cassava breeding and studying genes affecting the trait. PMID:21609492

  18. Neurotoxic effect of linamarin in rats associated with cassava (Manihot esculenta Crantz) consumption.

    PubMed

    Rivadeneyra-Domínguez, Eduardo; Vázquez-Luna, Alma; Rodríguez-Landa, Juan Francisco; Díaz-Sobac, Rafael

    2013-09-01

    Cassava (Manihot esculenta Crantz) is a plant widely used for food consumption in different processed products in rural areas of Africa, Asia, and Latin America. Cassava is a good source of carbohydrates and micronutrients. However, if it is not adequately processed or the consumer has nutritional deficiencies, then its cyanogenic glycoside (i.e., linamarin and lotaustralin) content makes it potentially neurotoxic. In the present study, the neurotoxic effects of different concentrations of linamarin (0.075, 0.15, 0.22, and 0.30 mg/kg) contained in cassava juice were evaluated in the open field and swim tests to identify locomotor alterations in adult male Wistar rats. The linamarin concentration in cassava juice was determined by high-performance liquid chromatography, and the juice was administered intraesophageally for 28 days. The results suggested that the consumption of linamarin in cassava juice increased the number of crossings and rearings in the open field test and caused behavioral deficiency, reflected by lateral swimming, in the swim test on days 21 and 28 of treatment. These alterations are possibly related to neuronal damage caused by linamarin in cassava juice in structures of the central nervous system involved in motor processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Two Cassava Basic Leucine Zipper (bZIP) Transcription Factors (MebZIP3 and MebZIP5) Confer Disease Resistance against Cassava Bacterial Blight.

    PubMed

    Li, Xiaolin; Fan, Shuhong; Hu, Wei; Liu, Guoyin; Wei, Yunxie; He, Chaozu; Shi, Haitao

    2017-01-01

    Basic domain-leucine zipper (bZIP) transcription factor, one type of conserved gene family, plays an important role in plant development and stress responses. Although 77 MebZIPs have been genome-wide identified in cassava, their in vivo roles remain unknown. In this study, we analyzed the expression pattern and the function of two MebZIPs ( MebZIP3 and MebZIP5 ) in response to pathogen infection. Gene expression analysis indicated that MebZIP3 and MebZIP5 were commonly regulated by flg22, Xanthomonas axonopodis pv. manihotis ( Xam ), salicylic acid (SA), and hydrogen peroxide (H 2 O 2 ). Subcellular localization analysis showed that MebZIP3 and MebZIP5 are specifically located in cell nucleus. Through overexpression in tobacco, we found that MebZIP3 and MebZIP5 conferred improved disease resistance against cassava bacterial blight, with more callose depositions. On the contrary, MebZIP3- and MebZIP5 -silenced plants by virus-induced gene silencing (VIGS) showed disease sensitive phenotype, lower transcript levels of defense-related genes and less callose depositions. Taken together, this study highlights the positive role of MebZIP3 and MebZIP5 in disease resistance against cassava bacterial blight for further utilization in genetic improvement of cassava disease resistance.

  20. Cassava: constraints to production and the transfer of biotechnology to African laboratories.

    PubMed

    Bull, Simon E; Ndunguru, Joseph; Gruissem, Wilhelm; Beeching, John R; Vanderschuren, Hervé

    2011-05-01

    Knowledge and technology transfer to African institutes is an important objective to help achieve the United Nations Millennium Development Goals. Plant biotechnology in particular enables innovative advances in agriculture and industry, offering new prospects to promote the integration and dissemination of improved crops and their derivatives from developing countries into local markets and the global economy. There is also the need to broaden our knowledge and understanding of cassava as a staple food crop. Cassava (Manihot esculenta Crantz) is a vital source of calories for approximately 500 million people living in developing countries. Unfortunately, it is subject to numerous biotic and abiotic stresses that impact on production, consumption, marketability and also local and country economics. To date, improvements to cassava have been led via conventional plant breeding programmes, but with advances in molecular-assisted breeding and plant biotechnology new tools are being developed to hasten the generation of improved farmer-preferred cultivars. In this review, we report on the current constraints to cassava production and knowledge acquisition in Africa, including a case study discussing the opportunities and challenges of a technology transfer programme established between the Mikocheni Agricultural Research Institute in Tanzania and Europe-based researchers. The establishment of cassava biotechnology platform(s) should promote research capabilities in African institutions and allow scientists autonomy to adapt cassava to suit local agro-ecosystems, ultimately serving to develop a sustainable biotechnology infrastructure in African countries.

  1. GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

    NASA Astrophysics Data System (ADS)

    Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

    2013-03-01

    Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

  2. Feeding behavior of feedlot lambs fed diets containing levels of cassava wastewater.

    PubMed

    de Aguiar Silva, Paula; de Carvalho, Gleidson Giordano Pinto; Pires, Aureliano José Vieira; Santos, Stefanie Alvarenga; Dos Santos Pina, Douglas; Silva, Robério Rodrigues; Rodrigues, Carlindo Santos; de Matos, Luis Henrique Almeida; Eiras, Carlos Emanuel; Novais-Eiras, Daiane; Nunes, Wilson Souza

    2018-04-01

    In this study, we evaluated the effects of including cassava wastewater in the diet on the feeding behavior of feedlot lambs in 35 male uncastrated Santa Inês × Dorper crossbred lambs at an approximate age of 3 months, with an average live weight of 20.0 ± 3.4 kg. Diets were formulated with hay of cassava shoots (roughage) and a concentrate based on corn and soybean, with a roughage:concentrate ratio of 50:50, plus inclusion of cassava wastewater at the levels of 0, 12, 24, 36, or 48 g/kg of the total diet. Feeding behavior was evaluated between the 46th and 52nd days of the experiment. Increasing cassava wastewater levels in the diet reduced (P < 0.05) the intakes (kg/day) of dry matter and neutral detergent fiber as well as the efficiency of rumination (g/cud and g/h) of dry matter and neutral detergent fiber. The other behavioral parameters were not affected by wastewater inclusion in the diet. Therefore, the inclusion of up to 48 g/kg of cassava wastewater on fresh matter of diets is not recommended for feedlot lambs.

  3. Heart rot of Virginia pine in Maryland

    Treesearch

    Richard H. Fenton; Frederick H. Berry

    1956-01-01

    Loggers and sawmill men have been wary of purchasing Virginia pine sawtimber. They point out that a heart rot, locally called "red heart, may spell the difference between profit and loss on a logging job. It is difficult to detect this rot in standing Virginia pine. It is even harder to estimate the volume loss. And total losses can be determined only after...

  4. High-resolution linkage map and chromosome-scale genome assembly for cassava ( Manihot esculenta Crantz) from 10 populations

    DOE PAGES

    Lyons, Jessica

    2014-12-11

    Cassava Manihot esculenta Crantz) is a major staple crop in Africa, Asia, and South America, and its starchy roots provide nourishment for 800 million people worldwide. Although native to South America, cassava was brought to Africa 400–500 years ago and is now widely cultivated across sub-Saharan Africa, but it is subject to biotic and abiotic stresses. To assist in the rapid identification of markers for pathogen resistance and crop traits, and to accelerate breeding programs, we generated a framework map for M. esculent Crantz from reduced representation sequencing [genotyping-by-sequencing (GBS)]. The composite 2412-cM map integrates 10 biparental maps (comprising 3480more » meioses) and organizes 22,403 genetic markers on 18 chromosomes, in agreement with the observed karyotype. Here, we used the map to anchor 71.9% of the draft genome assembly and 90.7% of the predicted protein-coding genes. The chromosome-anchored genome sequence will be useful for breeding improvement by assisting in the rapid identification of markers linked to important traits, and in providing a framework for genomic selectionenhanced breeding of this important crop.« less

  5. High-resolution linkage map and chromosome-scale genome assembly for cassava ( Manihot esculenta Crantz) from 10 populations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lyons, Jessica

    Cassava Manihot esculenta Crantz) is a major staple crop in Africa, Asia, and South America, and its starchy roots provide nourishment for 800 million people worldwide. Although native to South America, cassava was brought to Africa 400–500 years ago and is now widely cultivated across sub-Saharan Africa, but it is subject to biotic and abiotic stresses. To assist in the rapid identification of markers for pathogen resistance and crop traits, and to accelerate breeding programs, we generated a framework map for M. esculent Crantz from reduced representation sequencing [genotyping-by-sequencing (GBS)]. The composite 2412-cM map integrates 10 biparental maps (comprising 3480more » meioses) and organizes 22,403 genetic markers on 18 chromosomes, in agreement with the observed karyotype. Here, we used the map to anchor 71.9% of the draft genome assembly and 90.7% of the predicted protein-coding genes. The chromosome-anchored genome sequence will be useful for breeding improvement by assisting in the rapid identification of markers linked to important traits, and in providing a framework for genomic selectionenhanced breeding of this important crop.« less

  6. Konzo: From Poverty, Cassava, and Cyanogen Intake to Toxico-Nutritional Neurological Disease

    PubMed Central

    Nzwalo, Hipólito; Cliff, Julie

    2011-01-01

    Konzo is a distinct neurological entity with selective upper motor neuron damage, characterized by an abrupt onset of an irreversible, non-progressive, and symmetrical spastic para/tetraparesis. Despite its severity, konzo remains a neglected disease. The disease is associated with high dietary cyanogen consumption from insufficiently processed roots of bitter cassava combined with a protein-deficient diet. Epidemics occur when these conditions coincide at times of severe food shortage. Up to 1993, outbreaks in poor rural areas in Africa contributed to more than 3,700 cases of konzo. The number of affected people is underestimated. From unofficial reports, the number of cases was estimated to be at least 100,000 in 2000, in contrast to the 6,788 cases reported up to 2009 from published papers. PMID:21738800

  7. Iron oxide/cassava starch-supported Ziegler-Natta catalysts for in situ ethylene polymerization.

    PubMed

    Chancharoenrith, Sittikorn; Kamonsatikul, Choavarit; Namkajorn, Montree; Kiatisevi, Supavadee; Somsook, Ekasith

    2015-03-06

    Iron oxide nanoparticles were used as supporters for in situ polymerization to produce polymer nanocomposites with well-dispersed fillers in polymer matrix. Iron oxide could be sustained as colloidal solutions by cassava starch to produce a good dispersion of iron oxide in the matrix. New supports based on iron oxide/cassava starch or cassava starch for Ziegler-Natta catalysts were utilized as heterogeneous supporters for partially hydrolyzed triethylaluminum. Then, TiCl4 was immobilized on the supports as catalysts for polymerization of ethylene. High-density polyethylene (HDPE) composites were obtained by the synthesized catalysts. A good dispersion of iron oxide/cassava starch particles was observed in the synthesized polymer matrix promoting to good mechanical properties of HDPE. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Pathological and Molecular Characterization of Xanthomonas campestris Strains Causing Diseases of Cassava (Manihot esculenta)

    PubMed Central

    Verdier, Valérie; Boher, Bernard; Maraite, Henri; Geiger, Jean-Paul

    1994-01-01

    Fifty-one strains representing Xanthomonas campestris pv. manihotis and cassavae and different pathovars occurring on plants of the family Euphorbiaceae were characterized by ribotyping with a 16S+23S rRNA probe of Escherichia coli and by restriction fragment length polymorphism analysis with a plasmid probe from X. campestris pv. manihotis. Pathogenicity tests were performed on cassava (Manihot esculenta). Histological comparative studies were conducted on strains of two pathovars of X. campestris (vascular and mesophyllic) that attack cassava. Our results indicated that X. campestris pv. manihotis and cassavae have different modes of action in the host and supplemented the taxonomic data on restriction fragment length polymorphism that clearly separate the two pathovars. The plasmid probe could detect multiple restriction fragment length polymorphisms among strains of the pathovar studied. Ribotyping provides a useful tool for rapid identification of X. campestris pathovars on cassava. Images PMID:16349463

  9. Occurrence of Regulated Mycotoxins and Other Microbial Metabolites in Dried Cassava Products from Nigeria.

    PubMed

    Abass, Adebayo B; Awoyale, Wasiu; Sulyok, Michael; Alamu, Emmanuel O

    2017-06-29

    Dried cassava products are perceived as one of the potential sources of mycotoxin ingestion in human foods. Processing either contributes to the reduction of toxins or further exposes products to contamination by microorganisms that release metabolic toxins into the products. Thus, the prevalence of microbial metabolites in 373 processed cassava products was investigated in Nigeria. With the use of liquid chromatography tandem-mass spectrometry (LC-MS/MS) for the constituent analysis, a few major mycotoxins (aflatoxin B₁ and G₁, fumonisin B₁ and B₂, and zearalenone) regulated in food crops by the Commission of the European Union were found at concentrations which are toxicologically acceptable in many other crops. Some bioactive compounds were detected at low concentrations in the cassava products. Therefore, the exposure of cassava consumers in Nigeria to regulated mycotoxins was estimated to be minimal. The results provide useful information regarding the probable safety of cassava products in Nigeria.

  10. Cassava traits and end-user preference: Relating traits to consumer liking, sensory perception, and genetics.

    PubMed

    Bechoff, Aurélie; Tomlins, Keith; Fliedel, Geneviève; Becerra Lopez-Lavalle, Luis Augusto; Westby, Andrew; Hershey, Clair; Dufour, Dominique

    2018-03-04

    Breeding efforts have focused on improving agronomic traits of the cassava plant however little research has been done to enhance the crop palatability. This review investigates the links between cassava traits and end-user preference in relation with sensory characteristics. The main trait is starch and its composition related to the textural properties of the food. Pectin degradation during cooking resulted in increased mealiness. Nutritional components such as carotenoids made the cassava yellow but also altered sweetness and softness; however, yellow cassava was more appreciated by consumers than traditional (white) varieties. Components formed during processing such as organic acids gave fermented cassava products an acidic taste that was appreciated but the fermented smell was not always liked. Anti-nutritional compounds such as cyanogenic glucosides were mostly related to bitter taste. Post-harvest Physiological Deterioration (PPD) affected the overall sensory characteristics and acceptability. Genes responsible for some of these traits were also investigated. Diversity in cassava food products can provide a challenge to identifying acceptance criteria. Socio-economic factors such as gender may also be critical. This review leads to questions in relation to the adaptation of cassava breeding to meet consumer needs and preference in order to maximize income, health and food security.

  11. High-throughput microarray mapping of cell wall polymers in roots and tubers during the viscosity-reducing process.

    PubMed

    Huang, Yuhong; Willats, William G; Lange, Lene; Jin, Yanling; Fang, Yang; Salmeán, Armando A; Pedersen, Henriette L; Busk, Peter Kamp; Zhao, Hai

    2016-01-01

    Viscosity reduction has a great impact on the efficiency of ethanol production when using roots and tubers as feedstock. Plant cell wall-degrading enzymes have been successfully applied to overcome the challenges posed by high viscosity. However, the changes in cell wall polymers during the viscosity-reducing process are poorly characterized. Comprehensive microarray polymer profiling, which is a high-throughput microarray, was used for the first time to map changes in the cell wall polymers of sweet potato (Ipomoea batatas), cassava (Manihot esculenta), and Canna edulis Ker. over the entire viscosity-reducing process. The results indicated that the composition of cell wall polymers among these three roots and tubers was markedly different. The gel-like matrix and glycoprotein network in the C. edulis Ker. cell wall caused difficulty in viscosity reduction. The obvious viscosity reduction of the sweet potato and the cassava was attributed to the degradation of homogalacturonan and the released 1,4-β-d-galactan and 1,5-α-l-arabinan. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  12. Utilization of unpeeled cassava (Manihot esculenta Crantz) root meal supplemented with or without charcoal by broiler chickens.

    PubMed

    Oso, A O; Akapo, O; Sanwo, K A; Bamgbose, A M

    2014-06-01

    A 42-day feeding trial was conducted using 480-day-old, male Marshall broilers to study the utilization of unpeeled cassava root meal (UCRM) supplemented with or without 6 g/kg charcoal. The experimental design was laid out in a 3 × 2 factorial arrangement of treatments having three inclusion levels of UCRM (0, 100 and 200 g/kg) with or without 6 g/kg charcoal supplementation. Each treatment consisted of 80 birds replicated eight times with 10 birds per replicate. Main effect of inclusion level of UCRM and supplementation of charcoal showed reduced (p < 0.05) final live weight, weight gain, feed intake and apparent crude protein digestibility of the birds with increasing inclusion levels of UCRM. Birds fed diets supplemented with charcoal showed higher (p < 0.05) final live weight, weight gain and feed intake than birds fed diets without charcoal. Supplementation of charcoal in diet containing 100 g/kg UCRM resulted in improved (p < 0.05) weight gain when compared with birds fed similar diet but not supplemented with charcoal. Broilers fed diet containing no UCRM but supplemented with charcoal had the highest overall (p < 0.05) final live weight and weight gain, while birds fed diet containing 200 g/kg UCRM supplemented with charcoal recorded the poorest (p < 0.05) final live weight and weight gain. Serum glutamate oxaloacetate transaminase (SGOT) and serum thiocyanate concentration increased (p < 0.05) with increasing dietary inclusion levels of UCRM. Dietary supplementation of charcoal resulted in increased (p < 0.05) concentration of serum glucose and cholesterol and reduced (p < 0.05) SGOT concentration. Birds fed diets containing UCRM had high (p < 0.05) serum thiocyanate concentration irrespective of dietary supplementation or not with 6 g/kg charcoal. In conclusion, supplementation of diet containing up to 100 g/kg UCRM with 6 g/kg charcoal showed improved weight gain without any deleterious effect on serum metabolites. Journal of Animal Physiology and

  13. Sphaeropsis Collar Rot of Red and Jack Pines

    Treesearch

    Glen Stanosz; Linda Haugen; Joseph O' Brien

    2002-01-01

    Sphaeropsis collar rot has been detected in red and jack pines in Wisconsin and Michigan, and it could be affecting pines in other states. This disease may be less familiar than Sphaeropsis shoot blight, but both the incidence and the distribution of collar rot appear to be increasing.

  14. Cyanogenic potential of cassava peels and their detoxification for utilization as livestock feed.

    PubMed

    Tweyongyere, Robert; Katongole, Ignatious

    2002-12-01

    This study determined the cyanogenic potential of the cassava peels and assess the effectiveness of sun drying, heap fermentation and wet fermentation (soaking) in reducing the cyanide potential of the peels. Fresh cassava peels from major fresh food markets in Kampala and cassava grown in various parts of Uganda from Namolonge Agricultural and Animal Research Institute were used. The fresh peels from the market were subjected to the different detoxification methods foe 5 d; the cyanide potential was determined by enzymatic assay. The mean potential of the cassava peels from the food markets Kampala was 856 mg cyanide equivalen/kg of dry matter. The potential of the peels of the 14 cultivars fell between 253 and 1081 mg cyanide eQuivalent/kg of dry matter. High cyanogenic potential cultivars dominate on the market and pose danger of poisoning to livestock fed on fresh cassava peels. Treatment of the peels by sun-drying, heap fermentation on soaking reduced the cyanide potential to below 100 mg cyanide equivalent/kg of dry matter at 48, 72 and 96 h respectively. Sun-dying caused an early sharp fall in the cyanide potential, but heap fermentation or soaking gave the lowest residual cyanide after 120 h. Cassava peels could be safely used as livestock feed if they are treated to reduce the cyanogenic potential.

  15. Unravelling the Genetic Diversity among Cassava Bemisia tabaci Whiteflies Using NextRAD Sequencing.

    PubMed

    Wosula, Everlyne N; Chen, Wenbo; Fei, Zhangjun; Legg, James P

    2017-11-01

    Bemisia tabaci threatens production of cassava in Africa through vectoring viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). B. tabaci sampled from cassava in eight countries in Africa were genotyped using NextRAD sequencing, and their phylogeny and population genetics were investigated using the resultant single nucleotide polymorphism (SNP) markers. SNP marker data and short sequences of mitochondrial DNA cytochrome oxidase I (mtCOI) obtained from the same insect were compared. Eight genetically distinct groups were identified based on mtCOI, whereas phylogenetic analysis using SNPs identified six major groups, which were further confirmed by PCA and multidimensional analyses. STRUCTURE analysis identified four ancestral B. tabaci populations that have contributed alleles to the six SNP-based groups. Significant gene flows were detected between several of the six SNP-based groups. Evidence of gene flow was strongest for SNP-based groups occurring in central Africa. Comparison of the mtCOI and SNP identities of sampled insects provided a strong indication that hybrid populations are emerging in parts of Africa recently affected by the severe CMD pandemic. This study reveals that mtCOI is not an effective marker at distinguishing cassava-colonizing B. tabaci haplogroups, and that more robust SNP-based multilocus markers should be developed. Significant gene flows between populations could lead to the emergence of haplogroups that might alter the dynamics of cassava virus spread and disease severity in Africa. Continuous monitoring of genetic compositions of whitefly populations should be an essential component in efforts to combat cassava viruses in Africa. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. Phylogeny and expression pattern of starch branching enzyme family genes in cassava (Manihot esculenta Crantz) under diverse environments.

    PubMed

    Pei, Jinli; Wang, Huijun; Xia, Zhiqiang; Liu, Chen; Chen, Xin; Ma, Pingan; Lu, Cheng; Wang, Wenquan

    2015-08-01

    Starch branching enzyme (SBE) is one of the key enzymes involved in starch biosynthetic metabolism. In this study, six SBE family genes were identified from the cassava genome. Phylogenetic analysis divided the MeSBE family genes into dicot family A, B, C, and the new group. Tissue-specific analysis showed that MeSBE2.2 was strongly expressed in leaves, stems cortex, and root stele, and MeSBE3 had high expression levels in stem cortex and root stele of plants in the rapid growth stage under field condition, whereas the expression levels of MeSBE2.1, MeSBE4, and MeSBE5 were low except for in stems cortex. The transcriptional activity of MeSBE2.2 and MeSBE3 was higher compared with other members and gradually increased in the storage roots during root growth process, while the other MeSBE members normally remained low expression levels. Expression of MeSBE2.2 could be induced by salt, drought, exogenous abscisic acid, jasmonic acid, and salicylic acid signals, while MeSBE3 had positive response to drought, salt, exogenous abscisic acid, and salicylic acid in leaves but not in storage root, indicating that they might be more important in starch biosynthesis pathway under diverse environments.

  17. Occurrence of Regulated Mycotoxins and Other Microbial Metabolites in Dried Cassava Products from Nigeria

    PubMed Central

    Abass, Adebayo B.; Awoyale, Wasiu; Alamu, Emmanuel O.

    2017-01-01

    Dried cassava products are perceived as one of the potential sources of mycotoxin ingestion in human foods. Processing either contributes to the reduction of toxins or further exposes products to contamination by microorganisms that release metabolic toxins into the products. Thus, the prevalence of microbial metabolites in 373 processed cassava products was investigated in Nigeria. With the use of liquid chromatography tandem-mass spectrometry (LC-MS/MS) for the constituent analysis, a few major mycotoxins (aflatoxin B1 and G1, fumonisin B1 and B2, and zearalenone) regulated in food crops by the Commission of the European Union were found at concentrations which are toxicologically acceptable in many other crops. Some bioactive compounds were detected at low concentrations in the cassava products. Therefore, the exposure of cassava consumers in Nigeria to regulated mycotoxins was estimated to be minimal. The results provide useful information regarding the probable safety of cassava products in Nigeria. PMID:28661436

  18. Cassava brown streak virus has a rapidly evolving genome: implications for virus speciation, variability, diagnosis and host resistance

    PubMed Central

    Alicai, Titus; Ndunguru, Joseph; Sseruwagi, Peter; Tairo, Fred; Okao-Okuja, Geoffrey; Nanvubya, Resty; Kiiza, Lilliane; Kubatko, Laura; Kehoe, Monica A.; Boykin, Laura M.

    2016-01-01

    Cassava is a major staple food for about 800 million people in the tropics and sub-tropical regions of the world. Production of cassava is significantly hampered by cassava brown streak disease (CBSD), caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). The disease is suppressing cassava yields in eastern Africa at an alarming rate. Previous studies have documented that CBSV is more devastating than UCBSV because it more readily infects both susceptible and tolerant cassava cultivars, resulting in greater yield losses. Using whole genome sequences from NGS data, we produced the first coalescent-based species tree estimate for CBSV and UCBSV. This species framework led to the finding that CBSV has a faster rate of evolution when compared with UCBSV. Furthermore, we have discovered that in CBSV, nonsynonymous substitutions are more predominant than synonymous substitution and occur across the entire genome. All comparative analyses between CBSV and UCBSV presented here suggest that CBSV may be outsmarting the cassava immune system, thus making it more devastating and harder to control. PMID:27808114

  19. Preservation of hyphal-forming brown- and white-rot wood-inhabiting basidiomycetes

    Treesearch

    Suki C. Croan

    2001-01-01

    Lyophilization is an excellent technique for the long-term preservation of hyphal-forming brown-and white-rot wood-inhabiting basidiomycotina. However, vegetative mycelial isolates are not lyophilizable. In this study, 10 brown-rot and 10 white-rot basidiomycetous non-sporulating, non-chlamydosporulating, and non-bubillerferous basidiomycetes fungi were tested for...

  20. Toxic effects of prolonged administration of leaves of cassava (Manihot esculenta Crantz) to goats.

    PubMed

    Soto-Blanco, Benito; Górniak, Silvana Lima

    2010-07-01

    Cassava (Manihot esculenta Crantz) is a major source of dietary energy for humans and domestic animals in many tropical countries. However, consumption of cassava is limited by its characteristic content of cyanogenic glycosides. The present work aimed to evaluate the toxic effects of ingestion of cassava leaves by goats for 30 consecutive days, and to compare the results with the toxic effects of cyanide in goats, which have been described previously. Eight Alpine cross-bred female goats were divided into two equal groups, and were treated with ground frozen cassava leaves at a target dose of 6.0mg hydrogen cyanide (HCN)/kg/day (treated animals), or with ground hay and water only (control group) by gavage for 30 consecutive days. Blood samples were collected on days 0, 7, 15, 21, and 30 for biochemical panel and cyanide determination. At the end of the experiment, fragments of pancreas, thyroid gland, liver, kidney, lungs, heart, spleen, and the whole central nervous system were collected for histopathological examination. Clinical signs were observed in all goats treated with cassava on the first day of the experiment. From the second day the dose of cassava leaves was reduced to 4.5mgHCN/kg/day. No changes were found in the blood chemical panel. A mild increase in the number of resorption vacuoles in the thyroid follicular colloid, slight vacuolation of periportal hepatocytes, and spongiosis of the mesencephalon were found in goats treated with cassava. The pattern of lesions seen in the present goats was similar to what has been described previously in cyanide-dosed goats. Thus, the toxic effects of the ingestion of cassava leaves by goats can be attributed to the action of cyanide released from cyanogenic glycosides, and none of the effects was promoted by these glycosides directly.

  1. Anaerobic co-digestion of cyanide containing cassava pulp with pig manure.

    PubMed

    Glanpracha, Naraporn; Annachhatre, Ajit P

    2016-08-01

    Anaerobic co-digestion of cyanide-containing cassava pulp with pig manure was evaluated using laboratory scale mesophilic digester. The digester was operated in a semi-continuous mode with the mixed feedstock having C/N ratio of 35:1. Digester startup was accomplished in 60days with loading of 0.5-1kgVS/m(3)d. Subsequently, the loading to digester was increased step-wise from 2 to 9kgVS/m(3)d. Digester performance was stable at loading between 2 and 6kgVS/m(3)d with an average volatile solid removal and methane yield of 82% and 0.38m(3)/kgVSadded, respectively. However, beyond loading of 7kgVS/m(3)d, solubilization of particulate matter did not take place efficiently. Cyanide present in cassava pulp was successfully degraded indicating that anaerobic sludge in the digester was well acclimatized to cyanide. The results show that cassava pulp can be successfully digested anaerobically with pig manure as co-substrate without any inhibitory effect of cyanide present in the cassava pulp. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The emerging contribution of social wasps to grape rot disease ecology

    PubMed Central

    Boyden, Sean D.; Soriano, Jonathan-Andrew N.; Corey, Tyler B.; Leff, Jonathan W.; Fierer, Noah; Starks, Philip T.

    2017-01-01

    Grape sour (bunch) rot is a polymicrobial disease of vineyards that causes millions of dollars in lost revenue per year due to decreased quality of grapes and resultant wine. The disease is associated with damaged berries infected with a community of acetic acid bacteria, yeasts, and filamentous fungi that results in rotting berries with high amounts of undesirable volatile acidity. Many insect species cause the initial grape berry damage that can lead to this disease, but most studies have focused on the role of fruit flies in facilitating symptoms and vectoring the microorganisms of this disease complex. Like fruit flies, social wasps are abundant in vineyards where they feed on ripe berries and cause significant damage, while also dispersing yeasts involved in wine fermentation. Despite this, their possible role in disease facilitation and dispersal of grape rots has not been explored. We tested the hypothesis that the paper wasp Polistes dominulus could facilitate grape sour rot in the absence of other insect vectors. Using marker gene sequencing we characterized the bacterial and fungal community of wild-caught adults. We used a sterilized foraging arena to determine if these wasps transfer viable microorganisms when foraging. We then tested if wasps harboring their native microbial community, or those inoculated with sour rot, had an effect on grape sour rot incidence and severity using a laboratory foraging arena. We found that all wasps harbor some portion of the sour rot microbial community and that they have the ability to transfer viable microorganisms when foraging. Foraging by inoculated and uninoculated wasps led to an increase in berry rot disease symptom severity and incidence. Our results indicate that paper wasps can facilitate sour rot diseases in the absence of other vectors and that the mechanism of this facilitation may include both increasing host susceptibility and transmitting these microbial communities to the grapes. Social wasps are

  3. RAV transcription factors are essential for disease resistance against cassava bacterial blight via activation of melatonin biosynthesis genes.

    PubMed

    Wei, Yunxie; Chang, Yanli; Zeng, Hongqiu; Liu, Guoyin; He, Chaozu; Shi, Haitao

    2018-01-01

    With 1 AP2 domain and 1 B3 domain, 7 MeRAVs in apetala2/ethylene response factor (AP2/ERF) gene family have been identified in cassava. However, the in vivo roles of these remain unknown. Gene expression assays showed that the transcripts of MeRAVs were commonly regulated after Xanthomonas axonopodis pv manihotis (Xam) and MeRAVs were specifically located in plant cell nuclei. Through virus-induced gene silencing (VIGS) in cassava, we found that MeRAV1 and MeRAV2 are essential for plant disease resistance against cassava bacterial blight, as shown by the bacterial propagation of Xam in plant leaves. Through VIGS in cassava leaves and overexpression in cassava leave protoplasts, we found that MeRAV1 and MeRAV2 positively regulated melatonin biosynthesis genes and the endogenous melatonin level. Further investigation showed that MeRAV1 and MeRAV2 are direct transcriptional activators of 3 melatonin biosynthesis genes in cassava, as evidenced by chromatin immunoprecipitation-PCR in cassava leaf protoplasts and electrophoretic mobility shift assay. Moreover, cassava melatonin biosynthesis genes also positively regulated plant disease resistance. Taken together, this study identified MeRAV1 and MeRAV2 as common and upstream transcription factors of melatonin synthesis genes in cassava and revealed a model of MeRAV1 and MeRAV2-melatonin biosynthesis genes-melatonin level in plant disease resistance against cassava bacterial blight. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. The mutagenicity of cassava (Manihot esculenta Crantz) preparations.

    PubMed

    De Meester, C; Rollmann, B; Mupenda, K; Mary, Y

    1990-01-01

    Different cassava products were found to contain mutagenic activities in the Ames test. This paper describes how the flavonol quercetin is released during the cooking of fresh cassava leaves, following a process very similar to culinary habits. The hydrolysis of the glucoside(s) and the release of free quercetin has been followed by the monitoring of mutagenic activities with a simultaneous isolation and purification by thin-layer chromatography. The fluorodensitometric method applied revealed that fresh leaves contained about 1300 mg quercetin per kg wet weight, of which 800 mg were released during a normal cooking process.

  5. Efficient transformation and regeneration of transgenic cassava using the neomycin phosphotransferase gene as aminoglycoside resistance marker gene.

    PubMed

    Niklaus, Michael; Gruissem, Wilhelm; Vanderschuren, Hervé

    2011-01-01

    Cassava is one of the most important crops in the tropics. Its industrial use for starch and biofuel production is also increasing its importance for agricultural production in tropical countries. In the last decade cassava biotechnology has emerged as a valuable alternative to the breeding constraints of this highly heterozygous crop for improved trait development of cassava germplasm. Cassava transformation remains difficult and time-consuming because of limitations in selecting transgenic tissues and regeneration of transgenic plantlets. We have recently reported an efficient and robust cassava transformation protocol using the hygromycin phosphotransferase II (hptII) gene as selection marker and the aminoglycoside hygromycin at optimal concentrations to maximize the regeneration of transgenic plantlets. In the present work, we expanded the transformation protocol to the use of the neomycin phosphotransferase II (nptII) gene as selection marker. Several aminoglycosides compatible with the use of nptII were tested and optimal concentrations for cassava transformation were determined. Given its efficiency equivalent to hptII as selection marker with the described protocol, the use of nptII opens new possibilities to engineer transgenic cassava lines with multiple T-DNA insertions and to produce transgenic cassava with a resistance marker gene that is already deregulated in several commercial transgenic crops.

  6. Cytokinin-dependent secondary growth determines root biomass in radish (Raphanus sativus L.)

    PubMed Central

    Jang, Geupil; Lee, Jung-Hun; Rastogi, Khushboo; Park, Suhyoung; Oh, Sang-Hun; Lee, Ji-Young

    2015-01-01

    The root serves as an essential organ in plant growth by taking up nutrients and water from the soil and supporting the rest of the plant body. Some plant species utilize roots as storage organs. Sweet potatoes (Ipomoea batatas), cassava (Manihot esculenta), and radish (Raphanus sativus), for example, are important root crops. However, how their root growth is regulated remains unknown. In this study, we characterized the relationship between cambium and radial root growth in radish. Through a comparative analysis with Arabidopsis root expression data, we identified putative cambium-enriched transcription factors in radish and analysed their expression in representative inbred lines featuring distinctive radial growth. We found that cell proliferation activities in the cambium positively correlated with radial growth and final yields of radish roots. Expression analysis of candidate transcription factor genes revealed that some genes are differentially expressed between inbred lines and that the difference is due to the distinct cytokinin response. Taken together, we have demonstrated for the first time, to the best of our knowledge, that cytokinin-dependent radial growth plays a key role in the yields of root crops. PMID:25979997

  7. Formulation, sensory evaluation, proximate composition and storage stability of cassava strips produced from the composite flour of cassava and cowpea.

    PubMed

    Dada, Toluwase A; Barber, Lucretia I; Ngoma, Lubanza; Mwanza, Mulunda

    2018-03-01

    The study developed an acceptable formula for the production of cassava strips (a deep fried product) using composite flour of cassava/cowpea at four different levels of cowpea substitutions (100:0, 90:10, 80:20, and 70:30). Sensory properties, proximate composition, and shelf life at ambient temperature were determined. Proximate composition, shelf life, and microbial analysis were further done on the most preferred sample (80:20) and the control (100:0). Results showed a significant difference between the tested sample and the control, except in their moisture (4.1%-4.2%) and fiber (5.0%) contents which were similar. Protein content increased from 0.9% to 2.6%, fat 24.6% to 28.5%, carbohydrate 59.7% to 61.1%, and ash 1.8% to 2.5% in both control and most preferred sample. Results showed no changes in their peroxide value (2.4 mEq/kg), moisture content (4.1%), and bacterial count of 0 × 10 2  CFU/g at ambient storage temperature for 4 weeks. The addition of cowpea flour increased the nutritional quality of the cassava strips.

  8. Accuracies of univariate and multivariate genomic prediction models in African cassava.

    PubMed

    Okeke, Uche Godfrey; Akdemir, Deniz; Rabbi, Ismail; Kulakow, Peter; Jannink, Jean-Luc

    2017-12-04

    Genomic selection (GS) promises to accelerate genetic gain in plant breeding programs especially for crop species such as cassava that have long breeding cycles. Practically, to implement GS in cassava breeding, it is necessary to evaluate different GS models and to develop suitable models for an optimized breeding pipeline. In this paper, we compared (1) prediction accuracies from a single-trait (uT) and a multi-trait (MT) mixed model for a single-environment genetic evaluation (Scenario 1), and (2) accuracies from a compound symmetric multi-environment model (uE) parameterized as a univariate multi-kernel model to a multivariate (ME) multi-environment mixed model that accounts for genotype-by-environment interaction for multi-environment genetic evaluation (Scenario 2). For these analyses, we used 16 years of public cassava breeding data for six target cassava traits and a fivefold cross-validation scheme with 10-repeat cycles to assess model prediction accuracies. In Scenario 1, the MT models had higher prediction accuracies than the uT models for all traits and locations analyzed, which amounted to on average a 40% improved prediction accuracy. For Scenario 2, we observed that the ME model had on average (across all locations and traits) a 12% improved prediction accuracy compared to the uE model. We recommend the use of multivariate mixed models (MT and ME) for cassava genetic evaluation. These models may be useful for other plant species.

  9. Land Husbandry: Biochar application to reduce land degradation and erosion on cassava production

    NASA Astrophysics Data System (ADS)

    Yuniwati, E. D.

    2017-12-01

    This field experiment was carried out to examine the effect of increasing crop yield on land degradation and erosion in cassava-based cropping systems. The experiment was also aimed at showing that with proper crop management, the planting of cassava does not result in land degradation, and therefore, a sustainable production system can be obtained. The experiment was done in a farmer's fields in Batu, about 15 km south east of Malang, East Java, Indonesia. The soils are Alfisols with a surface slope of about 8%. There were 8 experimental treatments with two replications. The experiment results show that biochar applications reduce of soil erosion rate of the cassava field were not necessarily higher than those of maize in terms of crop yield and crop management. At low-to-medium yield, also observed the nutrient uptake of cassava was lower than that of maize. At high yield, only the K uptake of cassava was higher than that of maize, whereas the N and P uptake was more or less similar. Soil erosion on the cassava field was significantly higher than that on the maize field; however, this only occurred when there was no suitable crop management. Simple crop managements, such as ridging, biochar application, or manure application could significantly reduce soil erosion. The results also revealed that proper management could prevent land degradation and increase crop yield. In turn, the increase in crop yield could decrease soil erosion and plant nutrient depletion.

  10. Chemical Attributes of Soil Fertilized with Cassava Mill Wastewater and Cultivated with Sunflower

    PubMed Central

    Dantas, Mara Suyane Marques; Monteiro Rolim, Mário; Duarte, Anamaria de Sousa; de Silva, Ênio Farias de França; Maria Regis Pedrosa, Elvira; Dantas, Daniel da Costa

    2014-01-01

    The use of waste arising from agroindustrial activities, such as cassava wastewater, has been steadily implemented in order to reduce environmental pollution and nutrient utilization. The aim of this study is that the changes in chemical properties of dystrophic red-yellow latosol (oxisol) were evaluated at different sampling times after reuse of cassava wastewater as an alternative to mineral fertilizer in the cultivation of sunflower, hybrid Helio 250. The experiment was conducted at the Experimental Station of the Agricultural Research Company of Pernambuco (IPA), located in Vitória de Santo Antão. The experimental design was randomized blocks with 6 × 5 subplots; six doses of cassava wastewater (0; 8.5; 17.0; 34.0; 68.0; and 136 m3 ha−1); and five sampling times (21, 42, 63, 84, and 105 days after applying the cassava wastewater), with four replications. Concentrations of available phosphorus and exchangeable potassium, calcium, magnesium and sodium, pH, and electrical conductivity of the soil saturation extract were evaluated. Results indicate that cassava wastewater is an efficient provider of nutrients to the soil and thus to the plants, making it an alternative to mineral fertilizers. PMID:25610900

  11. The potential and biological test on cloned cassava crop remains on local sheep

    NASA Astrophysics Data System (ADS)

    Ginting, R.; Umar, S.; Hanum, C.

    2018-02-01

    This research aims at knowing the potential of cloned cassava crop remains dry matter and the impact of the feeding of the cloned cassava crop remains based complete feed on the consumption, the body weight gain, and the feed conversion of the local male sheep with the average of initial body weight of 7.75±1.75 kg. The design applied in the first stage research was random sampling method with two frames of tile and the second stage research applied Completely Randomized Design (CRD) with three (3) treatments and four (4) replicates. These treatments consisted of P1 (100% grass); P2 (50% grass, 50% complete feed pellet); P3 (100% complete feed from the raw material of cloned cassava crop remaining). Statistical tests showed that the feeding of complete feed whose raw material was from cloned cassava crop remains gave a highly significant impact on decreasing feed consumption, increasing body weight, lowering feed conversion, and increasing crude protein digestibility. The conclusion is that the cloned cassava crop remains can be used as complete sheep feed to replace green grass and can give the best result.

  12. Properties of cassava starch-based edible coating containing essential oils.

    PubMed

    Oriani, Vivian Boesso; Molina, Gustavo; Chiumarelli, Marcela; Pastore, Gláucia Maria; Hubinger, Miriam Dupas

    2014-02-01

    Edible coatings were produced using cassava starch (2% and 3% w/v) containing cinnamon bark (0.05% to 0.30% v/v) or fennel (0.05% to 0.30% v/v) essential oils. Edible cassava starch coating at 2% and 3% (w/v) containing or not containing 0.30% (v/v) of each essential oils conferred increased in water vapor resistance and decreased in the respiration rates of coated apple slices when compared with uncoated fruit. Cassava starch coatings (2% w/v) added 0.10% or 0.30% (v/v) fennel or cinnamon bark essential oils showed antioxidant capacity, and the addition of 0.30% (v/v) of each essential oil demonstrated antimicrobial properties. The coating containing cinnamon bark essential oil showed a significant antioxidant capacity, comparing to fennel essential oil. Antimicrobial tests showed that the addition of 0.30% (v/v) cinnamon bark essential oil to the edible coating inhibited the growth of Staphylococcus aureus and Salmonella choleraesuis, and 0.30% fennel essential oil inhibited just S. aureus. Treatment with 2% (w/v) of cassava starch containing 0.30% (v/v) of the cinnamon bark essential oil showed barrier properties, an antioxidant capacity and microbial inhibition. © 2014 Institute of Food Technologists®

  13. Development of a ROT22 - DATAMAP interface

    NASA Technical Reports Server (NTRS)

    Shenoy, K. R.; Waak, T.; Brieger, J. T.

    1986-01-01

    This report (Contract NAS2-10331- Mod 10), outlines the development and validation of an interface between the three-dimensional transonic analysis program ROT22 and the Data from Aeromechanics Test and Analytics-Management and Analysis Package (DATAMAP). After development of the interface, the validation is carried out as follows. First, the DATAMAP program is used to analyze a portion of the Tip Aerodynamics and Acoustics Test (TAAT) data. Specifically, records 2872 and 2873 are analyzed at an azimuth of 90 deg, and record 2806 is analyzed at 60 deg. Trim conditions for these flight conditions are then calculated using the Bell performance prediction program ARAM45. Equivalent shaft, pitch, and twist angles are calculated from ARAM45 results and used as input to the ROT22 program. The interface uses the ROT22 results and creates DATAMAP information files from which the surface pressure contours and sectional pressure coefficients are plotted. Twist angles input to ROT22 program are then iteratively modified in the tip region until the computed pressure coefficients closely match the measurements. In all cases studied, the location of the shock is well predicted. However, the negative pressure coefficients were underpredicted. This could be accounted for by blade vortex interaction effects.

  14. Regional heritability mapping provides insights into dry matter (DM) content in African white and yellow cassava populations

    USDA-ARS?s Scientific Manuscript database

    The HarvestPlus program for cassava (Manihot esculenta Crantz) fortifies cassava with beta-carotene by breeding for carotene-rich tubers (yellow cassava). However, a negative correlation between yellowness and dry matter (DM) content has been identified. Here, we investigated the genetic control of ...

  15. Validation of Reference Genes for Relative Quantitative Gene Expression Studies in Cassava (Manihot esculenta Crantz) by Using Quantitative Real-Time PCR

    PubMed Central

    Hu, Meizhen; Hu, Wenbin; Xia, Zhiqiang; Zhou, Xincheng; Wang, Wenquan

    2016-01-01

    Reverse transcription quantitative real-time polymerase chain reaction (real-time PCR, also referred to as quantitative RT-PCR or RT-qPCR) is a highly sensitive and high-throughput method used to study gene expression. Despite the numerous advantages of RT-qPCR, its accuracy is strongly influenced by the stability of internal reference genes used for normalizations. To date, few studies on the identification of reference genes have been performed on cassava (Manihot esculenta Crantz). Therefore, we selected 26 candidate reference genes mainly via the three following channels: reference genes used in previous studies on cassava, the orthologs of the most stable Arabidopsis genes, and the sequences obtained from 32 cassava transcriptome sequence data. Then, we employed ABI 7900 HT and SYBR Green PCR mix to assess the expression of these genes in 21 materials obtained from various cassava samples under different developmental and environmental conditions. The stability of gene expression was analyzed using two statistical algorithms, namely geNorm and NormFinder. geNorm software suggests the combination of cassava4.1_017977 and cassava4.1_006391 as sufficient reference genes for major cassava samples, the union of cassava4.1_014335 and cassava4.1_006884 as best choice for drought stressed samples, and the association of cassava4.1_012496 and cassava4.1_006391 as optimal choice for normally grown samples. NormFinder software recommends cassava4.1_006884 or cassava4.1_006776 as superior reference for qPCR analysis of different materials and organs of drought stressed or normally grown cassava, respectively. Results provide an important resource for cassava reference genes under specific conditions. The limitations of these findings were also discussed. Furthermore, we suggested some strategies that may be used to select candidate reference genes. PMID:27242878

  16. Incidence of cassava mosaic disease and associated whitefly vectors in South West and North Central Nigeria: Data exploration.

    PubMed

    Eni, Angela O; Efekemo, Oghenevwairhe P; Soluade, Mojisola G; Popoola, Segun I; Atayero, Aderemi A

    2018-08-01

    Cassava mosaic disease (CMD) is one of the most economically important viral diseases of cassava, an important staple food for over 800 million people in the tropics. Although several Cassava mosaic virus species associated with CMD have been isolated and characterized over the years, several new super virulent strains of these viruses have evolved due to genetic recombination between diverse species. In this data article, field survey data collected from 184 cassava farms in 12 South Western and North Central States of Nigeria in 2015 are presented and extensively explored. In each State, one cassava farm was randomly selected as the first farm and subsequent farms were selected at 10 km intervals, except in locations were cassava farms are sporadically located. In each selected farm, 30 cassava plants were sampled along two diagonals and all selected plant was scored for the presence or absence of CMD symptoms. Cassava mosaic disease incidence and associated whitefly vectors in South West and North Central Nigeria are explored using relevant descriptive statistics, box plots, bar charts, line graphs, and pie charts. In addition, correlation analysis, Analysis of Variance (ANOVA), and multiple comparison post-hoc tests are performed to understand the relationship between the numbers of whiteflies counted, uninfected farms, infected farms, and the mean of symptom severity in and across the States under investigation. The data exploration provided in this data article is considered adequate for objective assessment of the incidence and symptom severity of cassava mosaic disease and associated whitefly vectors in farmers' fields in these parts of Nigeria where cassava is heavily cultivated.

  17. Identification, Expression, and Functional Analysis of the Fructokinase Gene Family in Cassava.

    PubMed

    Yao, Yuan; Geng, Meng-Ting; Wu, Xiao-Hui; Sun, Chong; Wang, Yun-Lin; Chen, Xia; Shang, Lu; Lu, Xiao-Hua; Li, Zhan; Li, Rui-Mei; Fu, Shao-Ping; Duan, Rui-Jun; Liu, Jiao; Hu, Xin-Wen; Guo, Jian-Chun

    2017-11-12

    Fructokinase (FRK) proteins play important roles in catalyzing fructose phosphorylation and participate in the carbohydrate metabolism of storage organs in plants. To investigate the roles of FRKs in cassava tuber root development, seven FRK genes ( MeFRK1 - 7 ) were identified, and MeFRK1 - 6 were isolated. Phylogenetic analysis revealed that the MeFRK family genes can be divided into α ( MeFRK 1 , 2 , 6 , 7 ) and β ( MeFRK 3 , 4 , 5 ) groups. All the MeFRK proteins have typical conserved regions and substrate binding residues similar to those of the FRKs. The overall predicted three-dimensional structures of MeFRK1-6 were similar, folding into a catalytic domain and a β-sheet ''lid" region, forming a substrate binding cleft, which contains many residues involved in the binding to fructose. The gene and the predicted three-dimensional structures of MeFRK3 and MeFRK4 were the most similar. MeFRK1-6 displayed different expression patterns across different tissues, including leaves, stems, tuber roots, flowers, and fruits. In tuber roots, the expressions of MeFRK3 and MeFRK4 were much higher compared to those of the other genes. Notably, the expression of MeFRK3 and MeFRK4 as well as the enzymatic activity of FRK were higher at the initial and early expanding tuber stages and were lower at the later expanding and mature tuber stages. The FRK activity of MeFRK3 and MeFRK4 was identified by the functional complementation of triple mutant yeast cells that were unable to phosphorylate either glucose or fructose. The gene expression and enzymatic activity of MeFRK3 and MeFRK4 suggest that they might be the main enzymes in fructose phosphorylation for regulating the formation of tuber roots and starch accumulation at the tuber root initial and expanding stages.

  18. Mantakassa: an epidemic of spastic paraparesis associated with chronic cyanide intoxication in a cassava staple area of Mozambique. 2. Nutritional factors and hydrocyanic acid content of cassava products*

    PubMed Central

    1984-01-01

    An outbreak of spastic paraparesis which mostly affected women and children occurred in a northern province of Mozambique in 1981. The epidemic was related to chronic cyanide intoxication associated with a diet consisting almost exclusively of cassava. A prolonged drought in the area had exhausted all food resources except cassava, especially the bitter varieties. A nutritional, toxicological and botanical investigation was carried out in two of the five districts affected. The main findings were that cyanide levels were unusually high in the cassava plant as a consequence of the drought with daily intakes estimated at 15-31.5 mg HCN. Detoxification of the bitter varieties by sun-drying was inadequate because of the general food shortage, and metabolic detoxification was probably reduced owing to the absence of sulfur-containing amino acids in the diet. The raw and dried uncooked cassava was eaten mostly by women and children. The nutritional status of the population, however, was not very poor and symptoms of advanced under-nutrition were rarely seen. PMID:6088100

  19. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal.

    PubMed

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-04-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49-5.99 g N/(kg MLVSS⋅h) (MLVSS is mixed liquor volatile suspended solids) and 6.63-6.81 g N/(kg MLVSS⋅h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes.

  20. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

    PubMed Central

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-01-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS∙h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS∙h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes. PMID:25845364

  1. Increased expression of native cytosolic Cu/Zn superoxide dismutase and ascorbate peroxidase improves tolerance to oxidative and chilling stresses in cassava (Manihot esculenta Crantz).

    PubMed

    Xu, Jia; Yang, Jun; Duan, Xiaoguang; Jiang, Yueming; Zhang, Peng

    2014-08-05

    Cassava (Manihot esculenta Crantz) is a tropical root crop, and is therefore, extremely sensitive to low temperature; its antioxidative response is pivotal for its survival under stress. Timely turnover of reactive oxygen species (ROS) in plant cells generated by chilling-induced oxidative damages, and scavenging can be achieved by non-enzymatic and enzymatic reactions in order to maintain ROS homeostasis. Transgenic cassava plants that co-express cytosolic superoxide dismutase (SOD), MeCu/ZnSOD, and ascorbate peroxidase (APX), MeAPX2, were produced and tested for tolerance against oxidative and chilling stresses. The up-regulation of MeCu/ZnSOD and MeAPX2 expression was confirmed by the quantitative reverse transcriptase-polymerase chain reaction, and enzymatic activity analyses in the leaves of transgenic cassava plant lines with a single-transgene integration site. Upon exposure to ROS-generating agents, 100 μM ROS-generating reagent methyl viologen and 0.5 M H₂O₂, higher levels of enzymatic activities of SOD and APX were detected in transgenic plants than the wild type. Consequently, the oxidative stress parameters, such as lipid peroxidation, chlorophyll degradation and H₂O₂ synthesis, were lower in the transgenic lines than the wild type. Tolerance to chilling stress at 4°C for 2 d was greater in transgenic cassava, as observed by the higher levels of SOD, catalase, and ascorbate-glutathione cycle enzymes (e.g., APX, monodehydroascorbate reductase, dehydroascorbate reducatase and glutathione reductase) and lower levels of malondialdehyde content. These results suggest that the expression of native cytosolic SOD and APX simultaneously activated the antioxidative defense mechanisms via cyclic ROS scavenging, thereby improving its tolerance to cold stress.

  2. Tolerance to Phytophthora Fruit Rot in Watermelon Plant Introductions

    USDA-ARS?s Scientific Manuscript database

    Phytophthora capsici is distributed worldwide, and is an aggressive pathogen with a broad host range infecting solanaceous, leguminaceous, and cucurbitaceous crops. Fruit rot, caused by P. capsici is an emerging disease in most watermelon producing regions of Southeast US. Resistance to fruit rot o...

  3. Impacts of fungal stalk rot pathogens on physicochemical properties of sorghum grain

    USDA-ARS?s Scientific Manuscript database

    Stalk rot diseases are among the most ubiquitous and damaging fungal diseases of sorghum worldwide. Although reports of quantitative stalk rot yield losses are available, the impact of stalk rot on the physicochemical attributes of sorghum grain is currently unknown. This study was conducted to test...

  4. Improving Genomic Prediction in Cassava Field Experiments by Accounting for Interplot Competition

    PubMed Central

    Elias, Ani A.; Rabbi, Ismail; Kulakow, Peter; Jannink, Jean-Luc

    2018-01-01

    Plants competing for available resources is an unavoidable phenomenon in a field. We conducted studies in cassava (Manihot esculenta Crantz) in order to understand the pattern of this competition. Taking into account the competitive ability of genotypes while selecting parents for breeding advancement or commercialization can be very useful. We assumed that competition could occur at two levels: (i) the genotypic level, which we call interclonal, and (ii) the plot level irrespective of the type of genotype, which we call interplot competition or competition error. Modification in incidence matrices was applied in order to relate neighboring genotype/plot to the performance of a target genotype/plot with respect to its competitive ability. This was added into a genomic selection (GS) model to simultaneously predict the direct and competitive ability of a genotype. Predictability of the models was tested through a 10-fold cross-validation method repeated five times. The best model was chosen as the one with the lowest prediction root mean squared error (pRMSE) compared to that of the base model having no competitive component. Results from our real data studies indicated that <10% increase in accuracy was achieved with GS-interclonal competition model, but this value reached up to 25% with a GS-competition error model. We also found that the competitive influence of a cassava clone is not just limited to the adjacent neighbors but spreads beyond them. Through simulations, we found that a 26% increase of accuracy in estimating trait genotypic effect can be achieved even in the presence of high competitive variance. PMID:29358232

  5. Technical and Socioeconomic Potential of Biogas from Cassava Waste in Ghana.

    PubMed

    Kemausuor, Francis; Addo, Ahmad; Darkwah, Lawrence

    2015-01-01

    This study analyses technical potential and ex ante socioeconomic impacts of biogas production using cassava waste from agroprocessing plants. An analysis was performed for two biodigesters in two cassava processing communities in Ghana. The results showed that the two communities generate an excess of 4,500 tonnes of cassava peels per year. Using approximately 5% of the peels generated and livestock manure as inoculum can generate approximately 75,000 m(3) of gas with an estimated 60% methane content from two separate plants of capacities 500 m(3) and 300 m(3) in the two communities. If used internally as process fuel, the potential gas available could replace over 300 tonnes of firewood per year for cassava processing. The displacement of firewood with gas could have environmental, economic, and social benefits in creating sustainable development. With a 10 percent discount rate, an assumed 20-year biodigester will have a Net Present Value of approximately US$ 148,000, 7-year Payback Period, and an Internal Rate of Return of 18.7%. The project will create 10 full-time unskilled labour positions during the investment year and 4 positions during operation years.

  6. Technical and Socioeconomic Potential of Biogas from Cassava Waste in Ghana

    PubMed Central

    Kemausuor, Francis; Addo, Ahmad; Darkwah, Lawrence

    2015-01-01

    This study analyses technical potential and ex ante socioeconomic impacts of biogas production using cassava waste from agroprocessing plants. An analysis was performed for two biodigesters in two cassava processing communities in Ghana. The results showed that the two communities generate an excess of 4,500 tonnes of cassava peels per year. Using approximately 5% of the peels generated and livestock manure as inoculum can generate approximately 75,000 m3 of gas with an estimated 60% methane content from two separate plants of capacities 500 m3 and 300 m3 in the two communities. If used internally as process fuel, the potential gas available could replace over 300 tonnes of firewood per year for cassava processing. The displacement of firewood with gas could have environmental, economic, and social benefits in creating sustainable development. With a 10 percent discount rate, an assumed 20-year biodigester will have a Net Present Value of approximately US$ 148,000, 7-year Payback Period, and an Internal Rate of Return of 18.7%. The project will create 10 full-time unskilled labour positions during the investment year and 4 positions during operation years. PMID:26664752

  7. Soft rot erwiniae: from genes to genomes.

    PubMed

    Toth, Ian K; Bell, Kenneth S; Holeva, Maria C; Birch, Paul R J

    2003-01-01

    SUMMARY The soft rot erwiniae, Erwinia carotovora ssp. atroseptica (Eca), E. carotovora ssp. carotovora (Ecc) and E. chrysanthemi (Ech) are major bacterial pathogens of potato and other crops world-wide. We currently understand much about how these bacteria attack plants and protect themselves against plant defences. However, the processes underlying the establishment of infection, differences in host range and their ability to survive when not causing disease, largely remain a mystery. This review will focus on our current knowledge of pathogenesis in these organisms and discuss how modern genomic approaches, including complete genome sequencing of Eca and Ech, may open the door to a new understanding of the potential subtlety and complexity of soft rot erwiniae and their interactions with plants. The soft rot erwiniae are members of the Enterobacteriaceae, along with other plant pathogens such as Erwinia amylovora and human pathogens such as Escherichia coli, Salmonella spp. and Yersinia spp. Although the genus name Erwinia is most often used to describe the group, an alternative genus name Pectobacterium was recently proposed for the soft rot species. Ech mainly affects crops and other plants in tropical and subtropical regions and has a wide host range that includes potato and the important model host African violet (Saintpaulia ionantha). Ecc affects crops and other plants in subtropical and temperate regions and has probably the widest host range, which also includes potato. Eca, on the other hand, has a host range limited almost exclusively to potato in temperate regions only. Disease symptoms: Soft rot erwiniae cause general tissue maceration, termed soft rot disease, through the production of plant cell wall degrading enzymes. Environmental factors such as temperature, low oxygen concentration and free water play an essential role in disease development. On potato, and possibly other plants, disease symptoms may differ, e.g. blackleg disease is associated

  8. Reprogramming of cassava (Manihot esculenta) microspores towards sporophytic development.

    PubMed

    Perera, P I P; Ordoñez, C A; Dedicova, B; Ortega, P E M

    2014-05-21

    Gametes have the unique potential to enter the sporophytic pathway, called androgenesis. The plants produced are usually haploid and recombinant due to the preceding meiosis and they can double their chromosome number to form doubled haploids, which are completely homozygous. Availability of the doubled haploids facilitates mapping the genes of agronomically important traits, shortening the time of the breeding process required to produce new hybrids and homozygous varieties, and saving the time and cost for inbreeding. This study aimed to test the feasibility of using isolated and in vitro cultured immature cassava (Manihot esculenta) microspores to reprogramme and initiate sporophytic development. Different culture media and different concentrations of two ion components (Cu(2+) and Fe(2+)) were tested in two genotypes of cassava. External structural changes, nuclear divisions and cellular changes during reprogramming were analysed by scanning electron microscopy, by staining with 4',6-diamidino-2-phenylindole, and through classical histology and transmission electron microscopy. In two cassava genotypes, different developmental stages of microspores were found to initiate sporophytic cell divisions, that is, with tetrads of TMS 60444 and with mid or late uni-nucleate microspores of SM 1219-9. In the modified NLN medium (NLNS), microspore enlargements were observed. The medium supplemented with either sodium ferrous ethylene-diamine-tetraacetic acid (NaFeEDTA) or CuSO4·5H2O induced sporophytic cell division in both genotypes. A low frequency of the reprogramming and the presence of non-responsive microspores among the responsive ones in tetrads were found to be related to the viability and exine formation of the microspores. The present study clearly demonstrated that reprogramming occurs much faster in isolated microspore culture than in anther culture. This paves the way for the development of an efficient technique for the production of homozygous lines in

  9. Experimental study of bioethanol production using mixed cassava and durian seed

    NASA Astrophysics Data System (ADS)

    Seer, Q. H.; Nandong, J.; Shanon, T.

    2017-06-01

    The production of biofuels using conventional fermentation feedstocks, such as sugar-and starch-based agricultural crops will in the long-term lead to a serious competition with human-animal food consumption. To avoid this competition, it is important to explore various alternative feedstocks especially those from inedible waste materials. Potentially, fruit wastes such as damaged fruits, peels and seeds represent alternative cheap feedstocks for biofuel production. In this work, an experimental study was conducted on ethanol production using mixed cassava and durian seeds through fermentation by Saccharomyces cerevisiae yeast. The effects of pH, temperature and ratio of hydrolyzed cassava to durian seeds on the ethanol yield, substrate consumption and product formation rates were analyzed in the study. In flask-scale fermentation using the mixed cassava-durian seeds, it was found that the highest ethanol yield of 45.9 and a final ethanol concentration of 24.92 g/L were achieved at pH 5.0, temperature 35°C and 50:50 volume ratio of hydrolyzed cassava to durian seeds for a batch period of 48 hours. Additionally, the ethanol, glucose and biomass concentration profiles in a lab-scale bioreactor were examined for the fermentation using the proposed materials under the flask-scale optimum conditions. The ethanol yield of 35.7 and a final ethanol concentration of 14.61 g/L were obtained over a period of 46 hours where the glucose was almost fully consumed. It is worth noting that both pH and temperature have significant impacts on the fermentation process using the mixed cassava-durian seeds.

  10. Structure of Rot, a global regulator of virulence genes in Staphylococcus aureus.

    PubMed

    Zhu, Yuwei; Fan, Xiaojiao; Zhang, Xu; Jiang, Xuguang; Niu, Liwen; Teng, Maikun; Li, Xu

    2014-09-01

    Staphylococcus aureus is a highly versatile pathogen that can infect human tissue by producing a large arsenal of virulence factors that are tightly regulated by a complex regulatory network. Rot, which shares sequence similarity with SarA homologues, is a global regulator that regulates numerous virulence genes. However, the recognition model of Rot for the promoter region of target genes and the putative regulation mechanism remain elusive. In this study, the 1.77 Å resolution X-ray crystal structure of Rot is reported. The structure reveals that two Rot molecules form a compact homodimer, each of which contains a typical helix-turn-helix module and a β-hairpin motif connected by a flexible loop. Fluorescence polarization results indicate that Rot preferentially recognizes AT-rich dsDNA with ~30-base-pair nucleotides and that the conserved positively charged residues on the winged-helix motif are vital for binding to the AT-rich dsDNA. It is proposed that the DNA-recognition model of Rot may be similar to that of SarA, SarR and SarS, in which the helix-turn-helix motifs of each monomer interact with the major grooves of target dsDNA and the winged motifs contact the minor grooves. Interestingly, the structure shows that Rot adopts a novel dimerization model that differs from that of other SarA homologues. As expected, perturbation of the dimer interface abolishes the dsDNA-binding ability of Rot, suggesting that Rot functions as a dimer. In addition, the results have been further confirmed in vivo by measuring the transcriptional regulation of α-toxin, a major virulence factor produced by most S. aureus strains.

  11. Cassava dreg as replacement of corn in goat kid diets.

    PubMed

    Ferraz, Lucíola Vilarim; Guim, Adriana; Véras, Robson Magno Liberal; de Carvalho, Francisco Fernando Ramos; de Freitas, Marciela Thais Dino

    2018-02-01

    The effects of corn replacement by cassava dreg in diets of crossbred goat kids were evaluated. We tested the impacts of 0, 33, 66 and 100% replacement on intake, digestibility, feeding behaviour, performance and carcass characteristics. Thirty-six goat kids, aged between 4 and 5 months and with initial body weights of 17.61 ± 1.98 kg, were used in a completely randomised design. Analysis of regression revealed a negative linear effect on neutral detergent fibre (NDF) intake and a positive linear effect on non-fibrous carbohydrates (NFC) and hydrocyanic acids (HCN) intake. Cassava dreg use had a positive linear effect on organic matter digestibility and non-fibrous carbohydrates. Based on our results, cassava dreg use did not negatively impact animal performance, feeding behaviour and carcass characteristics, suggesting that it may replace corn up to 100% in the diets of confined goat kids.

  12. The nutritive value of cassava starch extraction residue for growing ducks.

    PubMed

    Abouelezz, Khaled; Yuan, Jianfeng; Wang, Guiping; Bian, Guozhi

    2018-02-26

    The cassava root meal (CRM) has been utilized as a cheap energy alternative to replace maize in poultry diets. Recently, the CRM in turn has an increasing demand for starch extraction industry, which renders large amounts of residues. This study evaluated the nutrient composition, amino acid profile, and feeding value of cassava starch extraction residue meal (CReM) for growing ducks. A total of 960, 11-day-old, ducklings were housed in 24 floor pens and allocated randomly into four dietary treatments: (i) 0CReM (control), (ii) 50 g CReM/kg, (iii) 100 g CReM/kg, and (iv) 150 g CReM/kg. The analyses (/kg) of CReM showed high gross energy (3306.88 kcal), ME (2109.54 kcal), and starch (514.0 g), with poor crude protein (20.9 g) and moderate crude fiber (140.0 g) and ash (60.0 g) contents. The total amino acid (AA) content amounted to 19.9 g/kg of CReM DM, in which the methionine, lysine, cystine, and isoleucine were present in low levels. The dietary inclusion of CReM up to 150 g/kg, between 11 and 42 days of age, had no significant effects (P > 0.05) on duck growth parameters, mortality, dressed weight, internal organs, or abdominal fat. Besides, the tested CReM levels did not show any significant effect on the blood proteins or liver enzymes. The results, therefore, revealed that the CReM contains a considerable amount of energy and could be incorporated successfully up to 150 g/kg in the diets of growing ducks.

  13. Statistical analysis of the factors that influenced the mechanical properties improvement of cassava starch films

    NASA Astrophysics Data System (ADS)

    Monteiro, Mayra; Oliveira, Victor; Santos, Francisco; Barros Neto, Eduardo; Silva, Karyn; Silva, Rayane; Henrique, João; Chibério, Abimaelle

    2017-08-01

    In order to obtain cassava starch films with improved mechanical properties in relation to the synthetic polymer in the packaging production, a complete factorial design 23 was carried out in order to investigate which factor significantly influences the tensile strength of the biofilm. The factors to be investigated were cassava starch, glycerol and modified clay contents. Modified bentonite clay was used as a filling material of the biofilm. Glycerol was the plasticizer used to thermoplastify cassava starch. The factorial analysis suggested a regression model capable of predicting the optimal mechanical property of the cassava starch film from the maximization of the tensile strength. The reliability of the regression model was tested by the correlation established with the experimental data through the following statistical analyse: Pareto graph. The modified clay was the factor of greater statistical significance on the observed response variable, being the factor that contributed most to the improvement of the mechanical property of the starch film. The factorial experiments showed that the interaction of glycerol with both modified clay and cassava starch was significant for the reduction of biofilm ductility. Modified clay and cassava starch contributed to the maximization of biofilm ductility, while glycerol contributed to the minimization.

  14. Application of edible coating from cassava peel – bay leaf on avocado

    NASA Astrophysics Data System (ADS)

    Handayani, M. N.; Karlina, S.; Sugiarti, Y.; Cakrawati, D.

    2018-05-01

    Avocados have a fairly short shelf life and are included in climacteric fruits. Edible coating application is one alternative to maintain the shelf life of avocado. Cassava peel starch is potential to be used as raw material for edible coating making. Addition of bay leaf extract containing antioxidants can increase the functional value of edible coating. The purpose of this study is to know the shrinkage of weight, acid number, color change and respiration rate of avocado coated with edible coating from cassava peel starch with an addition of bay leaf extract. The study consisted of making cassava peel starch, bay leaf extraction, edible coating making, edible coating application on avocado, and analysis of avocado characteristics during storage at room temperature. The results showed that addition of bay leaf extract on cassava peel starch edible coating applied to avocado, an effect on characteristics of avocado. Avocado applied edible coating and stored at room temperatures had lower weight loss than avocado without edible coating, lower acid number, tend to be more able to maintain color rather than avocado without edible coating.

  15. Optimization of factors to obtain cassava starch films with improved mechanical properties

    NASA Astrophysics Data System (ADS)

    Monteiro, Mayra; Oliveira, Victor; Santos, Francisco; Barros Neto, Eduardo; Silva, Karyn; Silva, Rayane; Henrique, João; Chibério, Abimaelle

    2017-08-01

    In this study, was investigated the optimization of the factors that significantly influenced the mechanical property improvement of cassava starch films through complete factorial design 23. The factors to be analyzed were cassava starch, glycerol and modified clay contents. A regression model was proposed by the factorial analysis, aiming to estimate the condition of the individual factors investigated in the optimum state of the mechanical properties of the biofilm, using the following statistical tool: desirability function and response surface. The response variable that delimits the improvement of the mechanical property of the biofilm is the tensile strength, such improvement is obtained by maximizing the response variable. The factorial analysis showed that the best combination of factor configurations to reach the best response was found to be: with 5g of cassava starch, 10% of glycerol and 5% of modified clay, both percentages in relation to the dry mass of starch used. In addition, the starch biofilm showing the lowest response contained 2g of cassava starch, 0% of modified clay and 30% of glycerol, and was consequently considered the worst biofilm.

  16. Fermentation Methods for Protein Enrichment of Cassava and Corn with Candida tropicalis

    PubMed Central

    Azoulay, Edgard; Jouanneau, Françoise; Bertrand, Jean-Claude; Raphael, Alain; Janssens, Jacques; Lebeault, Jean Michel

    1980-01-01

    Candida tropicalis grows on soluble starch, corn, and cassava powders without requiring that these substrates be previously hydrolyzed. C. tropicalis possesses the enzyme needed to hydrolyze starch, namely, an α-amylase. That property has been used to develop a fermentation process whereby C. tropicalis can be grown directly on corn or cassava powders so that the resultant mixture of biomass and residual corn or cassava contains about 20% protein, which represents a balanced diet for either animal fodder or human food. The fact that no extra enzymes are required to hydrolyze starch results in a particularly efficient way of improving the nutritional value of amylaceous products, through a single-step fermentation process. PMID:16345495

  17. Modification of cassava starch using combination process lactic acid hydrolysis and micro wave heating to increase coated peanut expansion quality

    NASA Astrophysics Data System (ADS)

    Sumardiono, Siswo; Pudjihastuti, Isti; Jos, Bakti; Taufani, Muhammad; Yahya, Faad

    2017-05-01

    Modified cassava starch is very prospective products in the food industry. The main consideration of this study is the increasing volume of imported wheat and the demand for modified cassava starch industry. The purpose of this study is the assessing of lactic acid hydrolysis and microwave heating impact to the physicochemical and rheological properties of modified cassava starch, and test applications of modified cassava starch to coated peanut expansion quality. Experimental variables include the concentration of lactic acid (0.5% w/w, 1% w/w; 2% w/w), a time of hydrolysis (15, 30, 45 minutes), a time of microwave heating (1, 2, 3 hours). The research step is by dissolving lactic acid using aquadest in the stirred tank reactor, then added cassava starch. Hydrolysed cassava starch was then heated by microwave. Physicochemical properties and rheology of the modified cassava starch is determined by the solubility, swelling power, and test congestion. The optimum obtained results indicate that solubility, swelling power, congestion test, respectively for 19.75%; 24.25% and 826.10% in the hydrolysis treatment for 15 minutes, 1% w lactic acid and microwave heating 3 hours. The physicochemical and rheological properties of modified cassava starch have changed significantly when compared to the native cassava starch. Furthermore, these modified cassava starch are expected to be used for the substitution of food products.

  18. Weevil - red rot associations in eastern white pine

    Treesearch

    Myron D. Ostrander; Clifford H. Foster

    1957-01-01

    The presence of red rot (Fomes pini) in pruned white pine stands has often been attributed to the act of pruning. This assumption may well be true for heavily stocked stands where thinning has been neglected and pruning scars are slow to heal. The question then arises: How do we account for the red rot often found in vigorous unpruned white pine stands? Evidence...

  19. Biofortified Cassava with Pro-Vitamin A Is Sensory and Culturally Acceptable for Consumption by Primary School Children in Kenya

    PubMed Central

    Talsma, Elise F.; Melse-Boonstra, Alida; de Kok, Brenda P. H.; Mbera, Gloria N. K.; Mwangi, Alice M.; Brouwer, Inge D.

    2013-01-01

    Background Biofortification of cassava with pro-vitamin A can potentially reduce vitamin A deficiency in low-income countries. However, little is known about consumer acceptance of this deep yellow variety of cassava compared to the commonly available white varieties. We aimed to determine the sensory and cultural acceptability of the consumption of pro-vitamin A rich cassava in order to identify key factors predicting the intention to consume pro-vitamin A rich cassava by families with school-aged children in Eastern Kenya. Methods Sensory acceptability was measured by replicated discrimination tests and paired preference tests among 30 children (7–12 yr) and 30 caretakers (18–45 yr) in three primary schools. Cultural acceptability was assessed with a questionnaire based on the combined model of The Theory of Planned Behavior and The Health Belief Model in one primary school among 140 caretakers of children aged 6 to 12 years. Correlations and multivariate analyses were used to determine associations between summed scores for model constructs. Results Caretakers and children perceived a significant difference in taste between white and pro-vitamin A rich cassava. Both preferred pro-vitamin A rich cassava over white cassava because of its soft texture, sweet taste and attractive color. Knowledge about pro-vitamin A rich cassava and it's relation to health (‘Knowledge’ ((β = 0.29, P = <.01)) was a strong predictor of ‘Health behavior identity’. Worries related to bitter taste and color (‘Perceived barriers 1’ (β = −0.21, P = .02)), the belief of the caretaker about having control to prepare cassava (‘Control beliefs’ (β = 0.18, P = .02)) and activities like information sessions about pro-vitamin A rich cassava and recommendations from health workers (‘Cues to action’(β = 0.51, P = <.01)) were the best predictors of intention to consume pro-vitamin A rich cassava. Conclusions Pro-vitamin A rich cassava is

  20. Application of enzyme-hydrolyzed cassava dregs as a carbon source in aquaculture.

    PubMed

    Shang, Qian; Tang, Haifang; Wang, Yinghui; Yu, Kefu; Wang, Liwei; Zhang, Ruijie; Wang, Shaopeng; Xue, Rui; Wei, Chaoshuai

    2018-02-15

    As a kind of tropical agricultural solid waste, cassava dregs had become a thorny nonpoint source pollution problem. This study investigated the feasibility of applying cassava dregs as a substitute for sucrose in biofloc technology (BFT) systems. Three types of biofloc systems (using three different carbon sources sucrose (BFT1), cassava dregs (BFT2) and enzyme-hydrolyzed cassava dregs (BFT3) respectively), and the control were constructed in this experiment in 200L tanks with a C/N ratio of 20/1. The comparison of the water quality indicators (The total ammonia nitrogen (TAN), nitrite (NO 2 - -N), nitrate (NO 3 - -N), chemical oxygen demand (COD)), biofloc for the above four groups was performed, and the results indicated that BFT3 showed greater potential to the formation of biofloc, which was beneficial for the water quality control. So the shrimp survival rate was the highest and the feed conversion rate was the lowest in BFT3. Besides, the high-throughput sequencing results showed that the relative abundance of heterotrophic bacteria in the top 30 dominant microbial communities in BFT3 was higher than those in BFT1 and BFT2 by 20.70% and 1.19%, respectively, which could decrease TAN to improve the water quality. Overall, the results had proved that the cassava dregs of enzymes hydrolysis could be used as an ideal and cheap carbon source in BFT. Copyright © 2017 Elsevier B.V. All rights reserved.