Biolistic transformation of Carrizo citrange (Citrus sinensis Osb. × Poncirus trifoliata L. Raf.).

PubMed

Wu, Hao; Acanda, Yosvanis; Jia, Hongge; Wang, Nian; Zale, Janice

2016-09-01

The development of transgenic citrus plants by the biolistic method. A protocol for the biolistic transformation of epicotyl explants and transgenic shoot regeneration of immature citrange rootstock, cv. Carrizo (Citrus sinensis Osb. × Poncirus trifoliata L. Raf.) and plant regeneration is described. Immature epicotyl explants were bombarded with a vector containing the nptII selectable marker and the gfp reporter. The number of independent, stably transformed tissues/total number of explants, recorded by monitoring GFP fluorescence 4 weeks after bombardment was substantial at 18.4 %, and some fluorescing tissues regenerated into shoots. Fluorescing GFP, putative transgenic shoots were micro-grafted onto immature Carrizo rootstocks in vitro, confirmed by PCR amplification of nptII and gfp coding regions, followed by secondary grafting onto older rootstocks grown in soil. Southern blot analysis indicated that all the fluorescing shoots were transgenic. Multiple and single copies of nptII integrations were confirmed in five regenerated transgenic lines. There is potential to develop a higher throughput biolistics transformation system by optimizing the tissue culture medium to improve shoot regeneration and narrowing the window for plant sampling. This system will be appropriate for transformation with minimal cassettes.

Comparative response of six grapevine rootstocks to inoculation with arbuscular mycorrhizal fungi based on root traits

NASA Astrophysics Data System (ADS)

Pogiatzis, Antreas; Bowen, Pat; Hart, Miranda; Holland, Taylor; Klironomos, John

2017-04-01

Arbuscular mycorrhizal (AM) symbiosis has been proven to be essential in grapevines, sustaining plant growth especially under abiotic and biotic stressors. The mycorrhizal growth response of young grapevines varies among rootstock cultivars and the underlying mechanisms involved in this variation are unknown. We predicted that this variation in mycorrhizal response may be explained by differences in root traits among rootstocks. We analyzed the entire root system of six greenhouse-grown rootstocks (Salt Creek, 3309 Couderc, Riparia Gloire, 101-14 Millardet et de Grasset, Swarzmann, Teleki 5C), with and without AM fungal inoculation (Rhizophagus irregularis) and characterized their morphological and architectural responses. Twenty weeks after the inoculation, aboveground growth was enhanced by AM colonization. The rootstock varieties were distinctly different in their response to AM fungi, with Salt Creek receiving the highest growth benefit, while Schwarzmann and 5C Teleki receiving the lowest. Plant responsiveness to AM fungi was negatively correlated with branching intensity (fine roots per root length). Furthermore, there was evidence that mycorrhizas can influence the expression of root traits, inducing a higher branching intensity and a lower root to shoot ratio. The results of this study will help to elucidate how interactions between grapevine rootstocks and AM fungi may benefit the establishment of new vineyards.

Hydraulic resistance components of mature apple trees on rootstocks of different vigours.

PubMed

Cohen, Shabtai; Naor, Amos; Bennink, John; Grava, Avraham; Tyree, Melvin

2007-01-01

Dwarfing of fruit trees is often achieved through the use of dwarfing rootstocks. Dwarf trees are characterized by sustained reductions in vegetative growth during the lifetime of the tree. The dwarfing mechanism is not well understood, but it has been hypothesized that hydraulic properties of the rootstock and the graft union are involved. It is hypothesized here that leaf- or stem-specific resistance of at least one hydraulic component of the water transport system would be negatively correlated with rootstock 'vigour', and this could be useful for selection of rootstocks. Hydraulic resistance (R) of fully grown apple trees on a variety of rootstocks of different 'vigours' was measured. Most measurements were with the evaporative flux (EF) method, where water uptake measured with sap flow sensors was related to the pressure gradient from soil (taken as pre-dawn leaf) and midday root (taken as covered root-sucker), stem (from covered leaf), and exposed and shaded leaf water potentials (Psi(l)). R of trees on dwarfing M9 rootstock was compared with that of more vigorous MM106 and MM111 rootstocks in Israel and Vermont, USA. In Israel, M9 consistently had higher leaf-specific hydraulic resistance (R(l)) in the soil to scion stem pathway, but this difference was only significant for one summer. R was larger in M9 between the root and stem, implicating the graft union as the site of increased resistance. In Vermont, R(l) of 9- and 10-year-old trees on six rootstocks of various vigours was not consistently related to vigour, and stem-specific resistance (R(s)) increased with increasing vigour. High pressure flow meter (HPFM) measurements gave a lower R than the EF method in all but one case, perhaps indicating a significant amount of xylem dysfunction in these trees, and demonstrated the increased resistivity of stem sections that included dwarf graft unions as compared with non-graft stem sections. It is concluded that stem- and leaf-specific R are not consistently positively correlated with dwarfing, although the increased resistivity of the graft union in dwarfing rootstocks may influence the transport of water and other elements across the graft union, and therefore be involved in the dwarfing mechanism.

Factors promoting infestation of newly planted, nonbearing apple orchards by dogwood borer (Lepidoptera: Sesiidae).

PubMed

Leskey, Tracy C; Bergh, J Christopher

2005-12-01

The initiation and level of infestation by dogwood borer, Synanthedon scitula (Harris), was tracked over three consecutive years in two nonbearing apple (Malus spp.) orchards in West Virginia and Virginia. The orchards were planted on a number of rootstock-variety (approximately cultivar) combinations and grown using different cultural practices. Infestations were detected during the first season after planting and continued to increase annually. The amount of burr knot tissue had the greatest impact on dogwood borer populations, because increasing amounts of burr knot tissue resulted in higher infestation rates. The use of plastic spiral wrap tree guards seemed to increase the development of burr knot tissue, resulting in significantly greater infestation compared with trees without tree guards in the West Virginia orchard. Variety also had a significant effect, because 'Idared' trees on M.26 had significantly greater levels of infestation compared with 'Buckeye Gala' on M.26, with or without tree guards, in the Virginia orchard. Mounding soil around the rootstock to a height just above the graft union prevented or tremendously curtailed infestation by dogwood borer, but it led to scion rooting that seemed to have an impact on size-controlling features of dwarfing rootstocks. Removal of the mounds at the beginning of the third growing season resulted in infestation of the rooted tissue during the same season. As long as apple cultivars continue to be planted on size-controlling rootstocks, dogwood borer will likely remain a serious pest, requiring either chemical treatments or a behavioral control strategy, such as mating disruption, to protect trees from infestation and damage.

Anatomical and Physiological Responses of Citrus Trees to Varying Boron Availability Are Dependent on Rootstock.

PubMed

Mesquita, Geisa L; Zambrosi, Fernando C B; Tanaka, Francisco A O; Boaretto, Rodrigo M; Quaggio, José A; Ribeiro, Rafael V; Mattos, Dirceu

2016-01-01

In Citrus, water, nutrient transport and thereby fruit production, are influenced among other factors, by the interaction between rootstock and boron (B) nutrition. This study aimed to investigate how B affects the anatomical structure of roots and leaves as well as leaf gas exchange in sweet orange trees grafted on two contrasting rootstocks in response to B supply. Plants grafted on Swingle citrumelo or Sunki mandarin were grown in a nutrient solution of varying B concentration (deficient, adequate, and excessive). Those grafted on Swingle were more tolerant to both B deficiency and toxicity than those on Sunki, as revealed by higher shoot and root growth. In addition, plants grafted on Sunki exhibited more severe anatomical and physiological damages under B deficiency, showing thickening of xylem cell walls and impairments in whole-plant leaf-specific hydraulic conductance and leaf CO2 assimilation. Our data revealed that trees grafted on Swingle sustain better growth under low B availablitlity in the root medium and still respond positively to increased B levels by combining higher B absorption and root growth as well as better organization of xylem vessels. Taken together, those traits improved water and B transport to the plant canopy. Under B toxicity, Swingle rootstock would also favor plant growth by reducing anatomical and ultrastructural damage to leaf tissue and improving water transport compared with plants grafted on Sunki. From a practical point of view, our results highlight that B management in citrus orchards shall take into account rootstock varieties, of which the Swingle rootstock was characterized by its performance on regulating anatomical and ultrastructural damages, improving water transport and limiting negative impacts of B stress conditions on plant growth.

Grafting influences phenolic profile and carpometric traits of fruits of greenhouse-grown eggplant (Solanum melongena L.).

PubMed

Kacjan Maršić, Nina; Mikulič-Petkovšek, Maja; Stampar, Franci

2014-10-29

The influence of eggplant grafting on tomato rootstock was evaluated during the two growing seasons. Yield, quality traits, and individual phenolics in fruits were assessed. Three commercial varieties and one landrace were used as scions. Grafting significantly increased eggplant yield and decreased the presence of calyx prickles. The effect of grafting on the accumulation of major phenolic constituents in eggplant fruit was inconsistent: in the year with less solar radiation and lower mean daily air temperatures, grafting decreased phenolic content in commercial variety/rootstock fruit and increased the content in landrace/rootstock fruit. An opposite effect in the latter combination was observed in the year with improved conditions for eggplant cultivation. The browning potential of fruit pulp was highly dependent on variety/landrace and partly also on grafting combination. Differences in correlations between phenolic constituents and browning potential (positive for varieties and negative for landrace) could also be ascribed to the importance of other antioxidants for diminished eggplant pulp browning.

Proteomic Study Related to Vascular Connections in Watermelon Scions Grafted onto Bottle-Gourd Rootstock under Different Light Intensities

PubMed Central

Muneer, Sowbiya; Ko, Chung Ho; Soundararajan, Prabhakaran; Manivnnan, Abinaya; Park, Yoo Gyeong; Jeong, Byoung Ryong

2015-01-01

Although grafting is broadly used in the production of crops, no information is available about the proteins involved in vascular connections between rootstock and scion. Similarly, proteome changes under the light intensities widely used for grafted seedlings are of practical use. The objective of this study was to determine the proteome of vascular connections using watermelon (Citrullus vulgaris Schrad.) ‘Sambok Honey’ and ‘Speed’ as the scion and bottle gourd (Lagenaria siceraria Stanld.) ‘RS Dongjanggun’ as the rootstock grown under different light intensities (25, 50, 75 and 100 μmol m−2 s−1). Our proteomic analysis revealed 24 and 27 differentially expressed proteins in ‘Sambok Honey’ and ‘Speed’, respectively, under different light intensities. The identified proteins were largely involved in ion binding, amino acid metabolism, transcriptional regulation and defense response. The enhancement of ion-binding, transcriptional regulation, amino acid metabolism, and defense response proteins suggests a strengthening of the connection between the rootstock and scion under high light intensity. Indeed, the accumulation of key enzymes in the biological processes described above appears to play an important role in the vascular connections of grafted seedlings. Moreover, it appears that 100 μmol m−2 s−1 results in better protein expression responses in grafted seedlings. PMID:25789769

Proteomic study related to vascular connections in watermelon scions grafted onto bottle-gourd rootstock under different light intensities.

PubMed

Muneer, Sowbiya; Ko, Chung Ho; Soundararajan, Prabhakaran; Manivnnan, Abinaya; Park, Yoo Gyeong; Jeong, Byoung Ryong

2015-01-01

Although grafting is broadly used in the production of crops, no information is available about the proteins involved in vascular connections between rootstock and scion. Similarly, proteome changes under the light intensities widely used for grafted seedlings are of practical use. The objective of this study was to determine the proteome of vascular connections using watermelon (Citrullus vulgaris Schrad.) 'Sambok Honey' and 'Speed' as the scion and bottle gourd (Lagenaria siceraria Stanld.) 'RS Dongjanggun' as the rootstock grown under different light intensities (25, 50, 75 and 100 μmol m-2 s-1). Our proteomic analysis revealed 24 and 27 differentially expressed proteins in 'Sambok Honey' and 'Speed', respectively, under different light intensities. The identified proteins were largely involved in ion binding, amino acid metabolism, transcriptional regulation and defense response. The enhancement of ion-binding, transcriptional regulation, amino acid metabolism, and defense response proteins suggests a strengthening of the connection between the rootstock and scion under high light intensity. Indeed, the accumulation of key enzymes in the biological processes described above appears to play an important role in the vascular connections of grafted seedlings. Moreover, it appears that 100 μmol m-2 s-1 results in better protein expression responses in grafted seedlings.

Photosynthetic Traits of Plants and the Biochemical Profile of Tomato Fruits Are Influenced by Grafting, Salinity Stress, and Growing Season.

PubMed

Marsic, Nina Kacjan; Vodnik, Dominik; Mikulic-Petkovsek, Maja; Veberic, Robert; Sircelj, Helena

2018-06-06

Changes in the photosynthetic traits of plants and metabolic composition of fruits of two tomato cultivars, grafted onto two rootstocks, grown in three salinity levels were studied in two growing periods during the season. Increased salinity stress conditions lowered water potential, stomatal conductance, and transpiration rate of grafted tomato plants, in both growing periods. Water deficit induced stomatal closure, which resulted in stomatal limitation of photosynthesis. The proline content in tomato leaves increased and was closely correlated with salinity. Some of the quality parameters of tomato fruits were affected by rootstock. The sugar/acid ratio was the highest in fruits of 'Belle'/'Maxifort' grafts. With increasing salt stress conditions from 40 to 60 mM NaCl, the lycopene content increased and ascorbic acid content decreased in fruits of 'Gardel'/'Maxifort' grafts, indicating the ability of this scion/rootstock combination to mitigate the toxicity effect of salinity stress. A higher phenolics concentration in fruits from the first growing period may be an additional indicator of stress, caused by higher temperatures and solar radiation, compared with the later period.

Grafting improves cucumber water stress tolerance in Saudi Arabia.

PubMed

Al-Harbi, Abdulaziz R; Al-Omran, Abdulrasoul M; Alharbi, Khadiga

2018-02-01

Water scarcity is a major limiting factor for crop productivity in arid and semi-arid areas. Grafting elite commercial cultivars onto selected vigorous rootstocks is considered as a useful strategy to alleviate the impact of environmental stresses. This study aims to investigate the feasibility of using grafting to improve fruit yield and quality of cucumber under water stress conditions. Alosama F 1 cucumber cultivar ( Cucumis sativus L.) was grafted onto Affyne ( Cucumis sativus L.) and Shintoza A90 ( Cucurbitamaxima × C. moschata ) rootstocks. Non-grafted plants were used as control. All genotypes were grown under three surface drip irrigation regimes: 50%, 75% and 100% of the crop evapotranspiration (ETc), which represent high-water stress, moderate-water stress and non-water stress conditions, respectively. Yield and fruit quality traits were analyzed and assessed. In comparison to the non-grafted plants, the best grafting treatment under water stress was Alosama F 1 grafted onto Shintoza A90 rootstock. It had an overall improved yield and fruit quality under water stress owing to an increase in the total fruit yield by 27%, from 4.815 kg plant -1 in non-grafted treatment to 6.149 kg plant -1 in grafted treatment under moderate -water stress, total soluble solid contents (13%), titratable acidity (39%) and vitamin C (33%). The soil water contents were low in soil surface and increase gradually with soil depth, while salt distribution showed an adverse trend. The positive effects of grafting on plant growth, productivity, and water use efficiency support this strategy as an useful tool for improving water stress tolerance in greenhouse grown cucumber in Saudi Arabia.

Yield and fruit quality traits of rambutan cultivars grafted onto a common rootstock and grown at two locations in Puerto Rico

USDA-ARS?s Scientific Manuscript database

The globalization of the economy, increased ethnic diversity and a greater demand for healthy and more diverse food products have opened a window of opportunity for the commercial production and marketing of tropical fruit, including rambutan (Nephelium lappaceum). There is a lack of formal experim...

Interaction of brassicaceous seed meal and apple rootstock on recovery of Pythium spp. and Pratylenchus penetrans from roots grown in replant soils

USDA-ARS?s Scientific Manuscript database

Pythium spp. and Pratylenchus penetrans are significant components of the diverse pathogen complex that incites apple replant disease in Washington state. The structure of the Pythium population differs among orchard soils but is composed of multiple pathogenic species. Studies were conducted to d...

Response of U.S. Bottle Gourd (Lagenaria siceraria) Plant Introductions (PI) to Crown Rot caused by Phytophthora Capsici

USDA-ARS?s Scientific Manuscript database

Phytophthora capsici can cause severe damage to cucurbit crops grown in open fields in the southeast regions of US. In recent years, there has been a growing interest in the US in grafting watermelon plants onto various cucurbit rootstocks including bottle gourds for managing soil borne diseases. ...

Transgenic watermelon rootstock resistant to CGMMV (cucumber green mottle mosaic virus) infection.

PubMed

Park, Sang Mi; Lee, Jung Suk; Jegal, Sung; Jeon, Bo Young; Jung, Min; Park, Yoon Sik; Han, Sang Lyul; Shin, Yoon Sup; Her, Nam Han; Lee, Jang Ha; Lee, Mi Yeon; Ryu, Ki Hyun; Yang, Seung Gyun; Harn, Chee Hark

2005-08-01

In watermelon, grafting of seedlings to rootstocks is necessary because watermelon roots are less viable than the rootstock. Moreover, commercially important watermelon varieties require disease-resistant rootstocks to reduce total watermelon yield losses due to infection with viruses such as cucumber green mottle mosaic virus (CGMMV). Therefore, we undertook to develop a CGMMV-resistant watermelon rootstock using a cDNA encoding the CGMMV coat protein gene (CGMMV-CP), and successfully transformed a watermelon rootstock named 'gongdae'. The transformation rate was as low as 0.1-0.3%, depending on the transformation method used (ordinary co-culture vs injection, respectively). However, watermelon transformation was reproducibly and reliably achieved using these two methods. Southern blot analysis confirmed that the CGMMV-CP gene was inserted into different locations in the genome either singly or multiple copies. Resistance testing against CGMMV showed that 10 plants among 140 T1 plants were resistant to CGMMV infection. This is the first report of the development by genetic engineering of watermelons resistant to CGMMV infection.

Greenhouse evaluation of capsicum rootstocks for management of meloidogyne incognita on grafted bell pepper

USDA-ARS?s Scientific Manuscript database

The growth, development, and nematode susceptibility of various rootstock genotypes grafted to a commercial bell pepper variety scion were evaluated in a series of greenhouse experiments. Nine rootstocks including ‘Caribbean Red Habanero’, ‘ PA-136’ , ‘Keystone Resistant Giant’, ‘Yolo Wonder’, ‘Car...

Progress in developing Armillaria resistant rootstocks for use with peach

USDA-ARS?s Scientific Manuscript database

GuardianTM (BY520-9) peach seedling rootstock was released in 1993 to provide a rootstock with superior resistance to peach tree short life (PTSL) which at the time was the number one cause of premature death of peach (Prunus persica L. [Batsch]) trees in the southeastern US. Since that time Guardi...

New citrus rootstocks released by USDA 2001-2010: field performance and nursery characteristics

USDA-ARS?s Scientific Manuscript database

Four new citrus rootstocks developed by USDA, ARS and released between 2001 and 2010 have gained considerable commercial popularity in Florida and have been used for propagation of more than 2 million trees over the last two years. Trends in commercial use of these rootstocks are discussed. Results ...

Grapevine rootstock effects on scion sap phenolic levels, resistance to Xylella fastidiosa infection, and progression of Pierce’s disease

USDA-ARS?s Scientific Manuscript database

The xylem-limited bacterium Xylella fastidiosa (Xf) causes Pierce’s disease (PD), an important disease of grapevine, Vitis vinifera L. Grapevine rootstocks were developed to provide increased resistance to root disease, but rootstock effects on cane and vine diseases remain unclear. Grapevines that ...

Growth, health and Liberibacter asiaticus titer in diverse citrus scions on mandarin vs. trifoliate hybrid rootstocks in a field planting with severe huanglongbing

USDA-ARS?s Scientific Manuscript database

Many recent publications and considerable discussion have focused on root health and the importance of rootstock response on huanglongbing (HLB) development, with special emphasis on bicarbonate intolerance of trifoliate hybrid rootstocks affecting HLB severity. USDA advanced citrus scion selections...

Unravelling rootstock×scion interactions to improve food security

PubMed Central

Albacete, Alfonso; Martínez-Andújar, Cristina; Martínez-Pérez, Ascensión; Thompson, Andrew J.; Dodd, Ian C.; Pérez-Alfocea, Francisco

2015-01-01

While much recent science has focused on understanding and exploiting root traits as new opportunities for crop improvement, the use of rootstocks has enhanced productivity of woody perennial crops for centuries. Grafting of vegetable crops has developed very quickly in the last 50 years, mainly to induce shoot vigour and to overcome soil-borne diseases in solanaceous and cucurbitaceous crops. In most cases, such progress has largely been due to empirical interactions between farmers, gardeners, and botanists, with limited insights into the underlying physiological mechanisms. Only during the last 20 years has science realized the potential of this old activity and studied the physiological and molecular mechanisms involved in rootstock×scion interactions, thereby not only explaining old phenomena but also developing new tools for crop improvement. Rootstocks can contribute to food security by: (i) increasing the yield potential of elite varieties; (ii) closing the yield gap under suboptimal growing conditions; (iii) decreasing the amount of chemical (pesticides and fertilizers) contaminants in the soil; (iv) increasing the efficiency of use of natural (water and soil) resources; (v) generating new useful genotypic variability (via epigenetics); and (vi) creating new products with improved quality. The potential of grafting is as broad as the genetic variability able to cross a potential incompatibility barrier between the rootstock and the scion. Therefore, understanding the mechanisms underlying the phenotypic variability resulting from rootstock×scion×environment interactions will certainly contribute to developing and exploiting rootstocks for food security. PMID:25754404

Effect of Soil Water Potential on Growth of Apple Trees Infected with Pratylenchus penetrans

PubMed Central

Jaffee, B. A.; Mai, W. F.

1979-01-01

Malling-Merton 106 apple rootstocks inoculated with Pratylenchus penetrans, or uninoculated, were grown in a growth chamber in pots of loamy sand maintained at two moisture levels, 0 to -0.4 bar or 0 to -10 bars. Either inoculation or low soil moisture suppressed shoot growth and increased root necrosis. However, the nematode-soil moisture interaction was not significant. PMID:19305552

Penetration and development of Meloidogyne arenaria on two new grape rootstocks.

PubMed

Anwar, Safdar A; McKenry, M V

2002-06-01

Penetration, development, and reproduction of a virulent 'Harmony' population of Meloidogyne arenaria was studied on two nematode-resistant grape rootstocks 10-17A and 6-19B. 'Cabernet Sauvignon' was used as a susceptible control for comparison. Plants were inoculated with 100 freshly hatched second-stage juveniles (J2) of M. arenaria. Greater numbers of J2 penetrated roots of 'Cabernet' than 10-17A, and none penetrated roots of 6-19B 4 days after inoculation (DAI). At 7 DAI, vermiform J2 advanced to sausage-shaped J2 in roots of 'Cabernet,' penetrated roots of 6-19B, and had egressed from roots of 10-17A. Resistant rootstocks expressed hypersensitive responses to penetrating J2 along the root epidermis, among the cortical cells, and along the differentiating vascular bundles. At 13 DAI, 68% of the J2 had attained globose stage in roots of 'Cabernet,' whereas there was no development of vermiform J2 in roots of the other two rootstocks. The nematodes reproduced only in roots of 'Cabernet.' Lack of development of J2 in roots of the two resistant grape rootstocks might be the result of a hypersensitive response to J2 feeding.

Photosynthesis is differently regulated during and after copper-induced nutritional stress in citrus trees.

PubMed

Hippler, Franz W R; Dovis, Veronica L; Boaretto, Rodrigo M; Quaggio, Jose A; Azevedo, Ricardo A; Williams, Lorraine E; Mattos, Dirceu

2018-04-17

Antioxidant enzymatic responses in Citrus leaves under Cu-induced stress depends on rootstock genotypes. However, there is a lack of information about how woody plants recover growth capacity after exposure to elevated Cu and whether growth is affected by the redistribution of the metal to new vegetative parts and consequently whether photosynthesis is affected. Therefore, the biomass of plants and Cu concentrations in new leaf flushes were determined in young citrus trees grafted onto contrasting rootstocks [Swingle citrumelo (SW) and Rangpur lime (RL)]. Photosynthetic rate, chlorophyll fluorescence and antioxidant enzymatic systems were evaluated in plants previously grown in nutrient solution with Cu varying from low to high levels and with no added Cu. Both rootstocks exhibited reduced plant growth under Cu toxicity. However, trees grafted onto RL exhibited better growth recovery after Cu excess, which was dependent on the modulation of antioxidant enzyme activities in roots and leaves that maintained the integrity of the photosynthetic apparatus. In contrast, plants grafted onto SW exhibited a lower photosynthetic rate at the lowest available Cu concentration. Although the highest accumulation of Cu occurred in citrus roots, the redistribution of the nutrient to new vegetative parts was proportional to the Cu concentration in the roots. This article is protected by copyright. All rights reserved.

Unravelling rootstock×scion interactions to improve food security.

PubMed

Albacete, Alfonso; Martínez-Andújar, Cristina; Martínez-Pérez, Ascensión; Thompson, Andrew J; Dodd, Ian C; Pérez-Alfocea, Francisco

2015-04-01

While much recent science has focused on understanding and exploiting root traits as new opportunities for crop improvement, the use of rootstocks has enhanced productivity of woody perennial crops for centuries. Grafting of vegetable crops has developed very quickly in the last 50 years, mainly to induce shoot vigour and to overcome soil-borne diseases in solanaceous and cucurbitaceous crops. In most cases, such progress has largely been due to empirical interactions between farmers, gardeners, and botanists, with limited insights into the underlying physiological mechanisms. Only during the last 20 years has science realized the potential of this old activity and studied the physiological and molecular mechanisms involved in rootstock×scion interactions, thereby not only explaining old phenomena but also developing new tools for crop improvement. Rootstocks can contribute to food security by: (i) increasing the yield potential of elite varieties; (ii) closing the yield gap under suboptimal growing conditions; (iii) decreasing the amount of chemical (pesticides and fertilizers) contaminants in the soil; (iv) increasing the efficiency of use of natural (water and soil) resources; (v) generating new useful genotypic variability (via epigenetics); and (vi) creating new products with improved quality. The potential of grafting is as broad as the genetic variability able to cross a potential incompatibility barrier between the rootstock and the scion. Therefore, understanding the mechanisms underlying the phenotypic variability resulting from rootstock×scion×environment interactions will certainly contribute to developing and exploiting rootstocks for food security. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Grafting: A Technique to Modify Ion Accumulation in Horticultural Crops

PubMed Central

Nawaz, Muhammad A.; Imtiaz, Muhammad; Kong, Qiusheng; Cheng, Fei; Ahmed, Waqar; Huang, Yuan; Bie, Zhilong

2016-01-01

Grafting is a centuries-old technique used in plants to obtain economic benefits. Grafting increases nutrient uptake and utilization efficiency in a number of plant species, including fruits, vegetables, and ornamentals. Selected rootstocks of the same species or close relatives are utilized in grafting. Rootstocks absorb more water and ions than self-rooted plants and transport these water and ions to the aboveground scion. Ion uptake is regulated by a complex communication mechanism between the scion and rootstock. Sugars, hormones, and miRNAs function as long-distance signaling molecules and regulate ion uptake and ion homeostasis by affecting the activity of ion transporters. This review summarizes available information on the effect of rootstock on nutrient uptake and utilization and the mechanisms involved. Information on specific nutrient-efficient rootstocks for different crops of commercial importance is also provided. Several other important approaches, such as interstocking (during double grafting), inarching, use of plant-growth-promoting rhizobacteria, use of arbuscular mycorrhizal fungi, use of plant growth substances (e.g., auxin and melatonin), and use of genetically engineered rootstocks and scions (transgrafting), are highlighted; these approaches can be combined with grafting to enhance nutrient uptake and utilization in commercially important plant species. Whether the rootstock and scion affect each other's soil microbiota and their effect on the nutrient absorption of rootstocks remain largely unknown. Similarly, the physiological and molecular bases of grafting, crease formation, and incompatibility are not fully identified and require investigation. Grafting in horticultural crops can help reveal the basic biology of grafting, the reasons for incompatibility, sensing, and signaling of nutrients, ion uptake and transport, and the mechanism of heavy metal accumulation and restriction in rootstocks. Ion transporter and miRNA-regulated nutrient studies have focused on model and non-grafted plants, and information on grafted plants is limited. Such information will improve the development of nutrient-efficient rootstocks. PMID:27818663

Grapevine rootstock effects on scion sap phenolic levels, resistance to Xylella fastidiosa infection, and progression of Pierce's disease

PubMed Central

Wallis, Christopher M.; Wallingford, Anna K.; Chen, Jianchi

2013-01-01

The xylem-limited bacterium Xylella fastidiosa (Xf) causes Pierce's disease (PD), an important disease of grapevine, Vitis vinifera L. Grapevine rootstocks were developed to provide increased resistance to root disease, but rootstock effects on cane and vine diseases remain unclear. Grapevines that consisted of Cabernet Sauvignon or Chardonnay grafted to 13 different rootstocks were inoculated with Xf and evaluated for PD severity and Xf titer after 6 months. A subset of six rootstock/scion combinations had xylem sap phenolic levels assessed in non-infected and Xf-infected grapevines. Vigor also was analyzed by measuring root lengths and masses. Cabernet Sauvignon grafted to 101-14MG, 1103P, 420A, or Schwarzmann had reduced PD severity compared to Cabernet Sauvignon grafted to 110R, 5BB, or SO4. Chardonnay grafted to Salt Creek or Freedom had reduced PD severity compared to Chardonnay grafted to RS3 or Schwarzmann. Chardonnay grafted to RS3 had greater Xf titer than Chardonnay grafted to 101-14MG, Freedom, or Salt Creek. No other differences in Xf titer among rootstocks were observed. Of the six scion/rootstock combinations which had xylem sap phenolics analyzed, Chardonnay/RS3 had the highest levels of most phenolics whereas Cabernet Sauvignon/101-14MG had the lowest phenolic levels. However, Chardonnay/101-14MG, which had mild PD symptoms, had greater sap levels of caftaric acid than other scion/rootstock combinations. Sap levels of caftaric acid, methyl salicylate, a procyanidin trimer, and quinic acid were greater in Xf-infected vs. non-infected grapevines. Chardonnay on 101-14MG or Salt Creek had greater root mass than Chardonnay on RS3. Cabernet Sauvignon on 101-14MG had greater root mass than Cabernet Sauvignon on 110R. These results identified rootstocks with the capacity for reducing PD symptom progression. Rootstocks also were shown to affect Xf titer, xylem sap phenolic levels, and plant vigor. PMID:24376452

Apple dwarfing rootstocks and interstocks affect the type of growth units produced during the annual growth cycle: precocious transition to flowering affects the composition and vigour of annual shoots.

PubMed

Seleznyova, Alla N; Tustin, D Stuart; Thorp, T Grant

2008-04-01

Precocious flowering in apple trees is often associated with a smaller tree size. The hypothesis was tested that floral evocation in axillary buds, induced by dwarfing rootstocks, reduces the vigour of annual shoots developing from these buds compared with shoots developing from vegetative buds. The experimental system provided a wide range of possible tree vigour using 'Royal Gala' scions and M.9 (dwarfing) and MM.106 (non-dwarfing) as rootstocks and interstocks. Second-year annual shoots were divided into growth units corresponding to periods (flushes) of growth namely, vegetative spur, extension growth unit, uninterrupted growth unit, floral growth unit (bourse) and extended bourse. The differences between the floral and vegetative shoots were quantified by the constituent growth units produced. The dwarfing influence was expressed, firstly, in reduced proportions of shoots that contained at least one extension growth unit and secondly, in reduced proportions of bicyclic shoots (containing two extension growth units) and shoots with an uninterrupted growth unit. In treatments where floral shoots were present, they were markedly less vigorous than vegetative shoots with respect to both measures. In treatments with M.9 rootstock, vegetative and floral shoots produced on average 0.52 and 0.17 extension growth units, compared with 0.77 extension growth units per shoot in the MM.106 rootstock treatment. Remarkably, the number of nodes per extension growth unit was not affected by the rootstock/interstock treatments. These results showed that rootstocks/interstocks affect the type of growth units produced during the annual growth cycle, reducing the number of extension growth units, thus affecting the composition and vigour of annual shoots. This effect is particularly amplified by the transition to flowering induced by dwarfing rootstocks. The division of annual shoot into growth units will also be useful for measuring and modelling effects of age on apple tree architecture.

Rootstock-to-scion transfer of transgene-derived small interfering RNAs and their effect on virus resistance in nontransgenic sweet cherry.

PubMed

Zhao, Dongyan; Song, Guo-qing

2014-12-01

Small interfering RNAs (siRNAs) are silencing signals in plants. Virus-resistant transgenic rootstocks developed through siRNA-mediated gene silencing may enhance virus resistance of nontransgenic scions via siRNAs transported from the transgenic rootstocks. However, convincing evidence of rootstock-to-scion movement of siRNAs of exogenous genes in woody plants is still lacking. To determine whether exogenous siRNAs can be transferred, nontransgenic sweet cherry (scions) was grafted on transgenic cherry rootstocks (TRs), which was transformed with an RNA interference (RNAi) vector expressing short hairpin RNAs of the genomic RNA3 of Prunus necrotic ringspot virus (PNRSV-hpRNA). Small RNA sequencing was conducted using bud tissues of TRs and those of grafted (rootstock/scion) trees, locating at about 1.2 m above the graft unions. Comparison of the siRNA profiles revealed that the PNRSV-hpRNA was efficient in producing siRNAs and eliminating PNRSV in the TRs. Furthermore, our study confirmed, for the first time, the long-distance (1.2 m) transfer of PNRSV-hpRNA-derived siRNAs from the transgenic rootstock to the nontransgenic scion in woody plants. Inoculation of nontransgenic scions with PNRSV revealed that the transferred siRNAs enhanced PNRSV resistance of the scions grafted on the TRs. Collectively, these findings provide the foundation for 'using transgenic rootstocks to produce products of nontransgenic scions in fruit trees'. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Graft union formation in artichoke grafting onto wild and cultivated cardoon: an anatomical study.

PubMed

Trinchera, Alessandra; Pandozy, Gianmarco; Rinaldi, Simona; Crinò, Paola; Temperini, Olindo; Rea, Elvira

2013-12-15

In order to develop a non-chemical method such as grafting effective against well-known artichoke soil borne diseases, an anatomical study of union formation in artichoke grafted onto selected wild and cultivated cardoon rootstocks, both resistant to Verticillium wilt, was performed. The cardoon accessions Belgio (cultivated cardoon) and Sardo (wild cardoon) were selected as rootstocks for grafting combinations with the artichoke cv. Romolo. Grafting experiments were carried out in the autumn and spring. The anatomical investigation of grafting union formation was conducted by scanning electron microscopy (SEM) on the grafting portions at the 3rd, 6th, 10th, 12th day after grafting. For the autumn experiment only, SEM analysis was also performed at 30 d after grafting. A high affinity between artichoke scion and cardoon rootstocks was observed, with some genotype differences in healing time between the two bionts. SEM images of scion/rootstock longitudinal sections revealed the appearance of many interconnecting structures between the two grafting components just 3d after grafting, followed by a vascular rearrangement and a callus development during graft union formation. De novo formation of many plasmodesmata between scion and rootstock confirmed their high compatibility, particularly in the globe artichoke/wild cardoon combination. Moreover, the duration of the early-stage grafting process could be influenced not only by the scion/rootstock compatibility, but also by the seasonal conditions, being favored by lower temperatures and a reduced light/dark photoperiod. Copyright © 2013 Elsevier GmbH. All rights reserved.

Transcriptome analysis reveals the effects of sugar metabolism and auxin and cytokinin signaling pathways on root growth and development of grafted apple.

PubMed

Li, Guofang; Ma, Juanjuan; Tan, Ming; Mao, Jiangping; An, Na; Sha, Guangli; Zhang, Dong; Zhao, Caiping; Han, Mingyu

2016-02-29

The root architecture of grafted apple (Malus spp.) is affected by various characteristics of the scions. To provide information on the molecular mechanisms underlying this influence, we examined root transcriptomes of M. robusta rootstock grafted with scions of wild-type (WT) apple (M. spectabilis) and a more-branching (MB) mutant at the branching stage. The growth rate of rootstock grafted MB was repressed significantly, especially the primary root length and diameter, and root weight. Biological function categories of differentially expressed genes were significantly enriched in processes associated with hormone signal transduction and intracellular activity, with processes related to the cell cycle especially down-regulated. Roots of rootstock grafted with MB scions displayed elevated auxin and cytokinin contents and reduced expression of MrPIN1, MrARF, MrAHP, most MrCRE1 genes, and cell growth-related genes MrGH3, MrSAUR and MrTCH4. Although auxin accumulation and transcription of MrPIN3, MrALF1 and MrALF4 tended to induce lateral root formation in MB-grafted rootstock, the number of lateral roots was not significantly changed. Sucrose, fructose and glucose contents were not decreased in MB-grafted roots compared with those bearing WT scions, but glycolysis and tricarboxylic acid cycle metabolic activities were repressed. Root resistance and nitrogen metabolism were reduced in MB-grafted roots as well. Our findings suggest that root growth and development of rootstock are mainly influenced by sugar metabolism and auxin and cytokinin signaling pathways. This study provides a basis that the characteristics of scions are related to root growth and development, resistance and activity of rootstocks.

A rootstock provides water conservation for a grafted commercial tomato (Solanum lycopersicum L.) line in response to mild-drought conditions: a focus on vegetative growth and photosynthetic parameters.

PubMed

Nilsen, Erik T; Freeman, Joshua; Grene, Ruth; Tokuhisa, James

2014-01-01

The development of water stress resistant lines of commercial tomato by breeding or genetic engineering is possible, but will take considerable time before commercial varieties are available for production. However, grafting commercial tomato lines on drought resistant rootstock may produce drought tolerant commercial tomato lines much more rapidly. Due to changing climates and the need for commercial production of vegetables in low quality fields there is an urgent need for stress tolerant commercial lines of vegetables such as tomato. In previous observations we identified a scion root stock combination ('BHN 602' scion grafted onto 'Jjak Kkung' rootstock hereafter identified as 602/Jjak) that had a qualitative drought-tolerance phenotype when compared to the non-grafted line. Based on this initial observation, we studied photosynthesis and vegetative above-ground growth during mild-drought for the 602/Jjak compared with another scion-rootstock combination ('BHN 602' scion grafted onto 'Cheong Gang' rootstock hereafter identified as 602/Cheong) and a non-grafted control. Overall above ground vegetative growth was significantly lower for 602/Jjak in comparison to the other plant lines. Moreover, water potential reduction in response to mild drought was significantly less for 602/Jjak, yet stomatal conductance of all plant-lines were equally inhibited by mild-drought. Light saturated photosynthesis of 602/Jjak was less affected by low water potential than the other two lines as was the % reduction in mesophyll conductance. Therefore, the Jjak Kkung rootstock caused aboveground growth reduction, water conservation and increased photosynthetic tolerance of mild drought. These data show that different rootstocks can change the photosynthetic responses to drought of a high yielding, commercial tomato line. Also, this rapid discovery of one scion-rootstock combination that provided mild-drought tolerance suggests that screening more scion-rootstock combination for stress tolerance may rapidly yield commercially viable, stress tolerant lines of tomato.

Budagovsky 9 rootstock: uncovering a novel resistance to fire blight

USDA-ARS?s Scientific Manuscript database

Budagovsky 9 (B.9) apple rootstock, displayed a high level of susceptibility (similar to M.9 rootstock) to fire blight bacteria (Erwinia amylovora) when leaves of non-grafted B.9 plants were inoculated. However, when older B.9 rootstock tissue was inoculated directly with E. amylovora, rootstock tis...

Rootstock scion somatogenetic interactions in perennial composite plants

PubMed Central

2014-01-01

The ancient plant production practice of grafting which instantly imparts new physiological properties to the desirable scion still remains shrouded in mystery. Yet, grafting remains a widely used technique in the production of several horticultural species. In a composite grafted plant, rootstocks control many aspects of scion growth and physiology including yield and quality attributes as well as biotic and abiotic stress tolerance. Broadly, physical, physiological, biochemical and molecular mechanisms have been reviewed to develop an integrated understanding of this enigmatic process that challenges existing genetic paradigms. This review summarizes the reported mechanisms underlying some of the economically important traits and identifies several key points to consider when conducting rootstock scion interaction experiments. Study of the somatogenetic interactions between rootstock and scion is a field that is ripe for discovery and vast improvements in the coming decade. Further, utilization of rootstocks based on a better understanding of the somatogenetic interactions is highly relevant in the current agricultural environment where there is a need for sustainable production practices. Rootstocks may offer a non-transgenic approach to rapidly respond to the changing environment and expand agricultural production of annual and perennial crops where grafting is feasible in order to meet the global food, fiber and fuel demands of the future. PMID:23793453

Apple rootstock evaluation for apple replant disease

USDA-ARS?s Scientific Manuscript database

Twenty-nine rootstocks from the Cornell-Geneva rootstock breeding program, some Budagovski rootstocks, M.9T337 and M.26EMLA were screened for apple replant disease (ARD) tolerance at Geneva, New York in 2008. Bench grafted rootstocks were planted in pots with two types of soil –clay loam and sandy l...

2015 Progress Report – Evaluation of the Cornell-Geneva Apple Rootstocks and Other Promising Apple Rootstocks

USDA-ARS?s Scientific Manuscript database

A number of new apple rootstocks from the Cornell/USDA apple rootstock breeding project, located at Geneva, NY which are resistant to fire blight are rapidly becoming available to the industry. These rootstocks are also dwarfing, tolerant to replant disease and productive. Data on cumulative yield...

Register of new fruit and nut cultivars list 47

USDA-ARS?s Scientific Manuscript database

Crop Listingsz. Almond, Almond Rootstock, Apple, Apricot and Pubescent-Skinned Prunophora Hybrids, Apricot Rootstock, Blackberry, Blue Honeysuckle, Blueberry, Citrus, Citrus Rootstock, Cranberry, Currant, Elderberry, Ligonberry, Grape, Nectarine, Peach, Peach Rootstock, Persian Walnut, Plum, Plum Ro...

Contributions of roots and rootstocks to sustainable, intensified crop production.

PubMed

Gregory, Peter J; Atkinson, Christopher J; Bengough, A Glyn; Else, Mark A; Fernández-Fernández, Felicidad; Harrison, Richard J; Schmidt, Sonja

2013-03-01

Sustainable intensification is seen as the main route for meeting the world's increasing demands for food and fibre. As demands mount for greater efficiency in the use of resources to achieve this goal, so the focus on roots and rootstocks and their role in acquiring water and nutrients, and overcoming pests and pathogens, is increasing. The purpose of this review is to explore some of the ways in which understanding root systems and their interactions with soils could contribute to the development of more sustainable systems of intensive production. Physical interactions with soil particles limit root growth if soils are dense, but root-soil contact is essential for optimal growth and uptake of water and nutrients. X-ray microtomography demonstrated that maize roots elongated more rapidly with increasing root-soil contact, as long as mechanical impedance was not limiting root elongation, while lupin was less sensitive to changes in root-soil contact. In addition to selecting for root architecture and rhizosphere properties, the growth of many plants in cultivated systems is profoundly affected by selection of an appropriate rootstock. Several mechanisms for scion control by rootstocks have been suggested, but the causal signals are still uncertain and may differ between crop species. Linkage map locations for quantitative trait loci for disease resistance and other traits of interest in rootstock breeding are becoming available. Designing root systems and rootstocks for specific environments is becoming a feasible target.

A new three-locus model for rootstock-induced dwarfing in apple revealed by genetic mapping of root bark percentage

PubMed Central

Harrison, Nicola; Harrison, Richard J.; Barber-Perez, Nuria; Cascant-Lopez, Emma; Cobo-Medina, Magdalena; Lipska, Marzena; Conde-Ruíz, Rebeca; Brain, Philip; Gregory, Peter J.; Fernández-Fernández, Felicidad

2016-01-01

Rootstock-induced dwarfing of apple scions revolutionized global apple production during the twentieth century, leading to the development of modern intensive orchards. A high root bark percentage (the percentage of the whole root area constituted by root cortex) has previously been associated with rootstock-induced dwarfing in apple. In this study, the root bark percentage was measured in a full-sib family of ungrafted apple rootstocks and found to be under the control of three loci. Two quantitative trait loci (QTLs) for root bark percentage were found to co-localize to the same genomic regions on chromosome 5 and chromosome 11 previously identified as controlling dwarfing, Dw1 and Dw2, respectively. A third QTL was identified on chromosome 13 in a region that has not been previously associated with dwarfing. The development of closely linked sequence-tagged site markers improved the resolution of allelic classes, thereby allowing the detection of dominance and epistatic interactions between loci, with high root bark percentage only occurring in specific allelic combinations. In addition, we report a significant negative correlation between root bark percentage and stem diameter (an indicator of tree vigour), measured on a clonally propagated grafted subset of the mapping population. The demonstrated link between root bark percentage and rootstock-induced dwarfing of the scion leads us to propose a three-locus model that is able to explain levels of dwarfing from the dwarf ‘M.27’ to the semi-invigorating rootstock ‘M.116’. Moreover, we suggest that the QTL on chromosome 13 (Rb3) might be analogous to a third dwarfing QTL, Dw3, which has not previously been identified. PMID:26826217

Vegetable Grafting as a Tool to Improve Drought Resistance and Water Use Efficiency

PubMed Central

Kumar, Pradeep; Rouphael, Youssef; Cardarelli, Mariateresa; Colla, Giuseppe

2017-01-01

Drought is one of the most prevalent limiting factors causing considerable losses in crop productivity, inflicting economic as well as nutritional insecurity. One of the greatest challenges faced by the scientific community in the next few years is to minimize the yield losses caused by drought. Drought resistance is a complex quantitative trait controlled by many genes. Thus, introgression of drought resistance traits into high yielding genotypes has been a challenge to plant breeders. Vegetable grafting using rootstocks has emerged as a rapid tool in tailoring plants to better adapt to suboptimal growing conditions. This has induced changes in shoot physiology. Grafting applications have expanded mainly in Solanaceous crops and cucurbits, which are commonly grown in arid and semi-arid areas characterized by long drought periods. The current review gives an overview of the recent scientific literature on root-shoot interaction and rootstock-driven alteration of growth, yield, and fruit quality in grafted vegetable plants under drought stress. Further, we elucidate the drought resistance mechanisms of grafted vegetables at the morpho-physiological, biochemical, and molecular levels. PMID:28713405

Evaluating paradox walnut rootstocks for resistance to Armillaria root disease

USDA-ARS?s Scientific Manuscript database

The most common Juglans regia (English walnut) rootstock in California is Paradox, a hybrid between J. hindsii (Northern California black walnut) and J. regia. Unfortuntely, Paradox rootstock is highly susceptible to Armillaria root disease. The relative resistance of new clonal, Paradox rootstock...

Developmental Response of a Resistance-Breaking Population of Meloidogyne arenaria on Vitis spp.

PubMed

Anwar, Safdar A; McKenry, M V

2002-03-01

Pre- and post-infection resistance mechanisms expressed by Vitis rootstocks RS-9 and Teleki 5C against second-stage juveniles (J2) of resistance-breaking populations of Meloidogyne arenaria were observed and correlated with juvenile development and nematode reproduction. Cabernet Sauvignon grape was used as a susceptible control for comparison. Similar numbers of J2 penetrated Teleki 5C and Cabernet Sauvignon roots. Root-tip necrosis, a hypersensitive reaction, occurred in both rootstocks but was effective in reducing J2 penetration only in RS-9 roots. Juvenile development occurred in roots of all three rootstocks by 13 days after inoculation, with the highest number of swollen juveniles present in Cabernet Sauvignon roots. Cortical necroses restricted the ability of J2 to reach vascular bundles, thereby restricting access to successful feeding sites and leading to dead or underdeveloped juveniles in RS-9 roots. At 35 days after inoculation, only 5% and 25% of the initial inoculum in RS-9 and Teleki 5C roots, respectively, reached the adult stage compared to 32% in Cabernet roots. Giant cells were of sufficient size to support nematode development to maturity in Cabernet. Cell necrosis and underdeveloped giant cells were apparent in the resistant rootstocks, which delayed development of adults and limited egg production. Inadequate development of giant cells may provide long-term population reductions in woody-rooted perennial crops.

Geneva apple rootstock performance in New York state and progress in commercialization

USDA-ARS?s Scientific Manuscript database

A number of new apple rootstocks from the Cornell/USDA apple rootstock breeding project, located at Geneva NY which are resistant to the bacterial disease fire blight (Erwinia amylovora) are rapidly becoming available. Some named rootstock genotypes from this program have previously been tested in s...

Regeneration systems for pyramiding disease resistance into walnut rootstocks

USDA-ARS?s Scientific Manuscript database

This study was conducted to regenerate selected walnut rootstocks adventitiously. This is an essential step to be able to produce transgenic walnut rootstocks with superior traits, such as disease resistance. A series of plant tissue culture experiments were conducted on RX1 and VX211 rootstocks wit...

Clarifying the effects of dwarfing rootstock on vegetative and reproductive growth during tree development: a study on apple trees.

PubMed

Costes, E; García-Villanueva, E

2007-08-01

Despite the widespread use of dwarfing rootstocks in the fruit-tree industry, their impact on tree architectural development and possible role in the within-tree balance between growth and flowering are still poorly understood, in particular during the early years of growth. The present study addressed this question in apple trees, through a detailed analysis of shoot populations, i.e. both vegetative and flowering shoots, during tree development. Architectural databases were constructed for trees of two cultivars that were either own-rooted or grafted on dwarfing rootstock. Within-tree shoot demographics and annual shoot characteristics, i.e. their dimensions, number of laterals and flowering, were observed from the first to the fifth year of growth and compared among scion/root system combinations. Differences in axis demographics appeared among scion/root system combinations after the second year of growth. Differences were found (a) in the number of long axes and (b) the number of medium axes. Dwarfing rootstock reduced the total number of axes developed in a tree, and this reduction resulted from proportionally more medium axes and spurs than long axes. The life span of spurs was also shortened. These phenomena appeared after an increase in flowering that started in the second year of growth and involved both axillary and terminal positions. Flowering regularity was also increased in grafted trees. These results confirm that the number of long shoots and flowering potential depend on the cultivar. They indicate that tree architectural plasticity in response to its root system mainly derives from the number of medium shoots developed and follows priorities within the whole tree axis population. There was also evidence for dwarfing rootstock involvement in adjusting the flowering abundance and that differences in flowering occurrence take precedence over those regarding vegetative growth during tree development.

Grafting response to excess boron and expression analysis of genes coding boron transporters in tomato.

PubMed

Di Gioia, F; Aprile, A; Sabella, E; Santamaria, P; Pardossi, A; Miceli, A; De Bellis, L; Nutricati, E

2017-09-01

Boron (B) is essential for plant growth, however its excess in soil and/or in irrigation water can severely compromise plant growth and yield. The goal of this work was to determine whether grafting onto 'Arnold', a commercial interspecific hybrid (Solanum lycopersicum × S. habrochaites) rootstock, which in a previous study was found to be tolerant to salt stress, could improve tomato (S. lycopersicum L. 'Ikram') tolerance to excess B, and whether this effect is associated with an exclusion mechanism. Non-grafted, self-grafted and grafted plants were hydroponically grown in a greenhouse with B concentration in the nutrient solution of 0.27 (control), 5, 10 and 15 mg·l -1 . A transcription analysis was carried out on SlNIP5 and SlBOR1 genes, which encode putative B transporters. Grafting 'Ikram' onto 'Arnold' rootstock reduced B concentration in leaf tissue of plants exposed to B concentrations of 10-15 mg·l -1 . At high B levels, SlNIP5 was down-regulated in all grafting combinations, while SlBOR1 was down-regulated only in the roots of plants grafted onto 'Arnold'. We conclude that grafting the susceptible tomato cultivar 'Ikram' onto the commercial rootstock 'Arnold' improved tolerance to excess B by reducing expression of genes encoding for B transporters at the root level, thus partially reducing the root uptake of B and its accumulation in the shoot. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

Apple dwarfing rootstocks exhibit an imbalance in carbohydrate allocation and reduced cell growth and metabolism

PubMed Central

Foster, Toshi M; McAtee, Peter A; Waite, Chethi N; Boldingh, Helen L; McGhie, Tony K

2017-01-01

Apple dwarfing rootstocks cause earlier shoot termination and reduced root and shoot mass. To identify physiological factors responsible for rootstock-induced growth restriction, we compared vascular-enriched gene expression between two dwarfing rootstocks (‘M27’ and ‘M9’) and the vigorous rootstock ‘M793’ using RNA sequencing and quantitative reverse transcriptase PCR. Differentially expressed genes common to both dwarfing rootstocks belonged to five main biological processes: (1) primary metabolism, (2) cell wall synthesis and modification, (3) secondary metabolism, (4) hormone signalling and response and (5) redox homeostasis. Genes promoting the biosynthesis of amino acids, lipids and cell walls were downregulated in dwarfing rootstocks, whereas genes promoting the breakdown of these compounds were upregulated. The only exception to this trend was the upregulation of starch synthesis genes in dwarfing rootstocks. Non-structural carbohydrate analysis demonstrated that starch concentrations in ‘M9’ roots, stems and grafted ‘Royal Gala’ (‘RG’) scions were double that of equivalent tissues from ‘RG’ homo-grafted trees (‘RG’/‘RG’). Fructose and glucose concentrations were much lower in all three tissues of the ‘RG’/‘M9’ trees. Together, these data indicate that dwarfing rootstocks are in a state of sugar depletion and reduced cellular activity despite having large starch reserves. Another significant finding was the over-accumulation of flavonoids and the downregulation of auxin influx transporters MdAUX1 and MdLAX2 in dwarfing rootstocks. We propose that both factors reduce polar auxin transport. The results of this study contribute novel information about the physiological state of dwarfing rootstocks. PMID:28435686

Comparative evaluation of oxidative enzyme activities during adventitious rooting in the cuttings of grapevine rootstocks.

PubMed

Kose, Cafer; Erdal, Serkan; Kaya, Ozkan; Atici, Okkeş

2011-03-15

This study investigated changes in peroxidase (POX) and polyphenol oxidase (PPO) activities through adventitious rooting in hardwood cuttings of grapevine rootstocks. Three grapevine rootstocks with different propensity to produce adventitious roots were selected: recalcitrant (Ramsey), non-recalcitrant (Rupestris du Lot) and intermediate (99R) cultivars. The averages of root number at 65 days were 96 in Lot, 76 in 99R and 30 in Ramsey. Both enzyme activities characteristically increased before adventitious rooting, regardless of rooting ability of the rootstocks, and then decreased. POX activity increased in Ramsey cuttings at 22 days, in Lot and 99R cuttings at 14 days after planting, and then decreased gradually until 51 days. The highest POX activity was determined in Ramsey rootstock with the highest rooting ability and the lowest activity was determined in the rootstocks with the lowest rooting ability. PPO activity gradually increased in Ramsey rootstock cuttings from 10 days to 22 days, in Lot and 99R cuttings at 14 days, and then decreased until 51 days. A significant correlation was identified between high POX activity and adventitious rooting capability in rootstocks, but the same result was not determined with PPO activity. A recalcitrant rooting variety cannot increase POX activity sufficiently before rooting. Therefore applications that could increase POX activity in stem cuttings during rooting may facilitate increased rooting in such rootstocks. Copyright © 2011 Society of Chemical Industry.

Simulating and sampling the hardwood component of loblolly pine plantations. In: Wensel, L.C.; Biging, G.S., tech

Treesearch

David Weise; G.R. Glover

1990-01-01

The hardwood component of young loblolly pine (Pinus taeda L.) plantations was simulated for use in a sampling study of competing vegetation. Spatial arrangement, total height, and crown area of hardwood rootstocks in 19 plantations 3 to 6 years old in Alabama and Georgia were used to develop the simulator. Rootstock arrangement ranged from uniform...

Bottle gourd rootstock-grafting affects nitrogen metabolism in NaCl-stressed watermelon leaves and enhances short-term salt tolerance.

PubMed

Yang, Yanjuan; Lu, Xiaomin; Yan, Bei; Li, Bin; Sun, Jin; Guo, Shirong; Tezuka, Takafumi

2013-05-01

The plant growth, nitrogen absorption, and assimilation in watermelon (Citrullus lanatus [Thunb.] Mansf.) were investigated in self-grafted and grafted seedlings using the salt-tolerant bottle gourd rootstock Chaofeng Kangshengwang (Lagenaria siceraria Standl.) exposed to 100mM NaCl for 3d. The biomass and NO3(-) uptake rate were significantly increased by rootstock while these values were remarkably decreased by salt stress. However, compared with self-grafted plants, rootstock-grafted plants showed higher salt tolerance with higher biomass and NO3(-) uptake rate under salt stress. Salinity induced strong accumulation of nitrate, ammonium and protein contents and a significant decrease of nitrogen content and the activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in leaves of self-grafted seedlings. In contrast, salt stress caused a remarkable decrease in nitrate content and the activities of GS and GOGAT, and a significant increase of ammonium, protein, and nitrogen contents and NR activity, in leaves of rootstock-grafted seedlings. Compared with that of self-grafted seedlings, the ammonium content in leaves of rootstock-grafted seedlings was much lower under salt stress. Glutamate dehydrogenase (GDH) activity was notably enhanced in leaves of rootstock-grafted seedlings, whereas it was significantly inhibited in leaves of self-grafted seedlings, under salinity stress. Three GDH isozymes were isolated by native gel electrophoresis and their expressions were greatly enhanced in leaves of rootstock-grafted seedlings than those of self-grafted seedlings under both normal and salt-stress conditions. These results indicated that the salt tolerance of rootstock-grafted seedlings might (be enhanced) owing to the higher nitrogen absorption and the higher activities of enzymes for nitrogen assimilation induced by the rootstock. Furthermore, the detoxification of ammonium by GDH when the GS/GOGAT pathway was inhibited under salt stress might play an important role in the release of salt stress in rootstock-grafted seedlings. Copyright © 2013 Elsevier GmbH. All rights reserved.

Integration of Cadmium Accumulation, Subcellular Distribution, and Physiological Responses to Understand Cadmium Tolerance in Apple Rootstocks

PubMed Central

Zhou, Jiangtao; Wan, Huixue; He, Jiali; Lyu, Deguo; Li, Huifeng

2017-01-01

Cadmium (Cd) is a nonessential and highly toxic element causing agricultural problems. However, little information is available about the variation in Cd tolerance among apple rootstocks and its underlying physiological regulation mechanisms. This study investigated Cd accumulation, subcellular distribution, and chemical forms as well as physiological changes among four apple rootstocks exposed to either 0 or 300 μM CdCl2. The results showed that variations in Cd tolerance existed among these rootstocks. Cd exposure caused decline in photosynthesis, chlorophyll and biomass in four apple rootstocks, which was less pronounced in M. baccata, indicating its higher Cd tolerance. This finding was corroborated with higher Cd tolerance indexes (TIs) of the whole plant in M. baccata than those in the other three apple rootstocks. Among the four apple rootstocks, M. baccata displayed the lowest Cd concentrations in roots, wood, and leaves, the smallest total Cd amounts as well as the lowest BCF. In apple rootstocks, it was found that to immobilize Cd in cell wall and soluble fraction (most likely in vacuole) and to convert it into pectate- or protein- integrated forms and undissolved Cd phosphate forms may be the primary strategies to reduce Cd mobility and toxicity. The physiological changes including ROS, carbohydrates and antioxidants were in line with the variations of Cd tolerance among four apple rootstocks. In comparison with the other three apple rootstocks, M. baccata had lower concentrations of ROS in roots and bark, H2O2 in roots and leaves and MDA in roots, wood and bark, but higher concentrations of soluble sugars in bark and starch in roots and leaves, and enhanced antioxidants. These results indicate that M. baccata are more tolerant to Cd stress than the other three apple rootstocks under the current experiment conditions, which is probably related to Cd accumulation, subcellular partitioning and chemical forms of Cd and well-coordinated antioxidant defense mechanisms. PMID:28638400

Micropropagation of peach rootstocks and cultivars.

PubMed

Balla, Ildikó; Mansvelt, Lucienne

2013-01-01

Peach (Prunus persica (L.) Batsch) is one of the most popular stone fruits, commercially produced largely in Mediterranean and, to a lesser extent, in continental climatic conditions. Several breeding programs with different aims release annually large numbers of new cultivars. Micropropagation offers a suitable method to provide the growers of sufficient quantities of rootstocks, as well as of pathogen-free planting material of old and new cultivars.An effective four-step micropropagation procedure for cultivar and rootstock production is described here, based on the use of modified MS and WPM media. The health status of the initial shoot tips is very important, also because the growth and proliferation rate of shoot cultures from virus-infected clones are generally very poor. Proliferation and elongation phases depend on the major macro-elements, as well as the content and ratio of plant growth regulators. It is important to grow the cultures at 22°C, as hyperhydricity may develop at higher temperatures. Although sucrose is the most common carbon source used during proliferation and rooting, for some peach cultivars and rootstocks the replacement of sucrose (10 g/L) with glucose (20 g/L) in the rooting medium improves the rooting and survival rates of plants in the acclimatization phase. The rooting rate of the rootstock "Cadaman" is improved with the chelated form of iron FeEDDHA at 150 mg/L. Rooted plants are acclimatized in greenhouse under high humidity conditions.

Physiological, biochemical and molecular responses in four Prunus rootstocks submitted to drought stress.

PubMed

Jiménez, Sergio; Dridi, Jihène; Gutiérrez, Diego; Moret, David; Irigoyen, Juan J; Moreno, María A; Gogorcena, Yolanda

2013-10-01

An understanding of the mechanisms that determine plant response to reduced water availability is essential to improve water-use efficiency (WUE) of stone fruit crops. The physiological, biochemical and molecular drought responses of four Prunus rootstocks (GF 677, Cadaman, ROOTPAC 20 and ROOTPAC(®) R) budded with 'Catherina' peach cultivar were studied. Trees were grown in 15-l containers and subjected to a progressive water stress for 26 days, monitoring soil moisture content by time domain reflectometry. Photosynthetic and gas exchange parameters were determined. Root and leaf soluble sugars and proline content were also measured. At the end of the experiment, stressed plants showed lower net photosynthesis rate, stomatal conductance and transpiration rate, and higher intrinsic leaf WUE (AN/gs). Soluble sugars and proline concentration changes were observed, in both root and leaf tissues, especially in an advanced state of stress. The accumulation of proline in roots and leaves with drought stress was related to the decrease in osmotic potential and increase in WUE, whereas the accumulation of sorbitol in leaves, raffinose in roots and proline in both tissues was related only to the increase in the WUE. Owing to the putative role of raffinose and proline as antioxidants and their low concentration, they could be ameliorating deleterious effects of drought-induced oxidative stress by protecting membranes and enzymes rather than acting as active osmolytes. Higher expression of P5SC gene in roots was also consistent with proline accumulation in the tolerant genotype GF 677. These results indicate that accumulation of sorbitol, raffinose and proline in different tissues and/or the increase in P5SC expression could be used as markers of drought tolerance in peach cultivars grafted on Prunus rootstocks.

Rooting and acclimatization of micropropagated marubakaido apple rootstock using Adesmia latifolia rhizobia.

PubMed

Muniz, Aleksander Westphal; de Sá, Enilson Luiz; Dalagnol, Gilberto Luíz; Filho, João Américo

2013-01-01

In vitro rooting and the acclimatization of micropropagated rootstocks of apple trees is essential for plant development in the field. The aim of this work was to assess the use of rhizobia of Adesmia latifolia to promote rooting and acclimatization in micropropagated Marubakaido apple rootstock. An experiment involving in vitro rooting and acclimatization was performed with four strains of rhizobium and two controls, one with and the other without the addition of synthetic indoleacetic acid. The inoculated treatments involved the use of sterile inoculum and inoculum containing live rhizobia. The most significant effects on the rooting rate, primary-root length, number of roots, root length, fresh-shoot biomass, and fresh-root biomass were obtained by inoculation with strain EEL16010B and with synthetic indole acetic acid. However, there was no difference in the growth of apple explants in the acclimatization experiments. Strain EEL16010B can be used to induce in vitro rooting of the Marubakaido rootstock and can replace the use of synthetic indoleacetic acid in the rooting of this cultivar.

Engineering cherry rootstocks with resistance to Prunus necrotic ring spot virus through RNAi-mediated silencing.

PubMed

Song, Guo-qing; Sink, Kenneth C; Walworth, Aaron E; Cook, Meridith A; Allison, Richard F; Lang, Gregory A

2013-08-01

Prunus necrotic ringspot virus (PNRSV) is a major pollen-disseminated ilarvirus that adversely affects many Prunus species. In this study, an RNA interference (RNAi) vector pART27-PNRSV containing an inverted repeat (IR) region of PNRSV was transformed into two hybrid (triploid) cherry rootstocks, 'Gisela 6' (GI 148-1) and 'Gisela 7'(GI 148-8)', which are tolerant and sensitive, respectively, to PNRSV infection. One year after inoculation with PNRSV plus Prune Dwarf Virus, nontransgenic 'Gisela 6' exhibited no symptoms but a significant PNRSV titre, while the transgenic 'Gisela 6' had no symptoms and minimal PNRSV titre. The nontransgenic 'Gisela 7' trees died, while the transgenic 'Gisela 7' trees survived. These results demonstrate the RNAi strategy is useful for developing viral resistance in fruit rootstocks, and such transgenic rootstocks may have potential to enhance production of standard, nongenetically modified fruit varieties while avoiding concerns about transgene flow and exogenous protein production that are inherent for transformed fruiting genotypes. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Tetraploid Carrizo citrange rootstock (Citrus sinensis Osb.×Poncirus trifoliata L. Raf.) enhances natural chilling stress tolerance of common clementine (Citrus clementina Hort. ex Tan).

PubMed

Oustric, Julie; Morillon, Raphaël; Luro, François; Herbette, Stéphane; Lourkisti, Radia; Giannettini, Jean; Berti, Liliane; Santini, Jérémie

2017-07-01

Low temperatures can disturb the development, growth and geographic distribution of plants, particularly cold-sensitive plants in the Mediterranean area, where temperatures can reach seasonally low levels. In citrus crops, scion/rootstock combinations are used to improve fruit production and quality, and increase tolerance to biotic and abiotic stresses. In the last decade, several studies have shown that tetraploid citrus seedlings or rootstocks are more tolerant to abiotic stress than their respective diploid. The objective of this study was to test whether the use of tetraploid rootstocks can improve the chilling tolerance of the scion. We compared physiological and biochemical responses to low seasonal temperatures of common Clementine (Citrus sinensis Osb.×Poncirus trifoliata L. Raf.) grafted on diploid and tetraploid Carrizo citrange rootstocks, named C/2xCC and C/4xCC, respectively. During the coldest months, C/4xCC showed a smaller decrease in net photosynthesis (Pn), stomatal conductance (G s ), chlorophyll fluorescence (F v /F m ), and starch levels, and lower levels of malondialdehyde and electrolyte leakage than C/2xCC. Specific activities of catalase (CAT), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) were higher in C/4xCC during the cold period, whereas chlorophyll, proline, ascorbate and hydrogen peroxide (H 2 O 2 ) levels and superoxide dismutase (SOD) activity did not vary significantly between C/4xCC and C/2xCC throughout the study period. Taken together, these results demonstrate that tetraploid Carrizo citrange rootstock improves the chilling tolerance of common clementine (scion) thanks to a part of the antioxidant system. Copyright © 2017. Published by Elsevier GmbH.

Four Biotypes of Tylenchulus semipenetrans in California Identified, and Their Importance in the Development of Resistant Citrus Rootstocks.

PubMed

Baines, R C; Cameron, J W; Soost, R K

1974-04-01

Four biotypes (pathotypes) of the citrus nematode, Tylenchulus semipenetrans, occurring in California, U.S.A. were differentiated on the basis of differences of infectivity on 'Homosassa' sweet orange, 'Troyer' citrange, 'Pomeroy' and 'Rubidoux' Poncirus trifoliata, 'Thompson Seedless' grape, and 'Manzanillo' olive. A method for differentiating biotypes of T. semipenetrans is described. Field observations indicate that biotypes of this nematode are very stable. The importance of using highly infective biotypes in the development and selection of satisfactory citrus-nematode-resistant rootstocks is emphasized.

Water limitation and rootstock genotype interact to alter grape berry metabolism through transcriptome reprogramming

PubMed Central

Berdeja, Mariam; Nicolas, Philippe; Kappel, Christian; Dai, Zhan Wu; Hilbert, Ghislaine; Peccoux, Anthony; Lafontaine, Magali; Ollat, Nathalie; Gomès, Eric; Delrot, Serge

2015-01-01

Grapevine is a perennial crop often cultivated by grafting a scion cultivar on a suitable rootstock. Rootstocks influence scions, particularly with regard to water uptake and vigor. Therefore, one of the possibilities to adapt viticulture to the extended drought stress periods is to select rootstocks conferring increased tolerance to drought. However, the molecular mechanisms associated with the ability of rootstock/scion combination to influence grape berry metabolism under drought stress are still poorly understood. The transcriptomic changes induced by drought stress in grape berries (cv. Pinot noir) from vines grafted on either 110R (drought-tolerant) or 125AA (drought-sensitive) rootstock were compared. The experiments were conducted in the vineyard for two years and two grape berry developmental stages (50% and 100% veraison). The genome-wide microarray approach showed that water stress strongly impacts gene expression in the berries, through ontology categories that cover cell wall metabolism, primary and secondary metabolism, signaling, stress, and hormones, and that some of these effects strongly depend on the rootstock genotype. Indeed, under drought stress, berries from vines grafted on 110R displayed a different transcriptional response compared to 125AA-concerning genes related to jasmonate (JA), phenylpropanoid metabolism, and pathogenesis-related proteins. The data also suggest a link between JA and secondary metabolism in water-stressed berries. Overall, genes related to secondary metabolism and JA are more induced and/or less repressed by drought stress in the berries grafted on the drought-sensitive rootstock 125AA. These rootstock-dependent gene expression changes are relevant for berry composition and sensory properties. PMID:26504567

Effect of Saline Water Irrigation on Growth and Physiological Responses of Three Rose Rootstocks

PubMed Central

Niu, Genhua; Rodriguez, Denise S.; Aguiniga, Lissie

2009-01-01

Salt-tolerant landscape plants are needed for arid and semiarid regions where the supply of quality water is limited and soil salinization often occurs. This study evaluated growth, chloride (Cl) and sodium (Na) uptake, relative chlorophyll content, and chlorophyll fluorescence of three rose rootstocks [Rosa ×fortuniana Lindl., R. multiflora Thunb., and R. odorata (Andr.) Sweet] irrigated with saline solutions at 1.6 (control), 3.0, 6.0, or 9.0 dS·m −1 electrical conductivity in a greenhouse. After 15 weeks, most plants in 9.0 dS·m −1 treatment died regardless of rootstock. Significant growth reduction was observed in all rootstocks at 6.0 dS·m −1 compared with the control and 3.0 dS·m −1, but the reduction in R. ×fortuniana was smaller than in the other two rootstocks. The visual scores of R. multiflora at 3.0 and 6.0 dS·m−1 were slightly lower than those of the other rootstocks. Rosa odorata had the highest shoot Na concentration followed by R. multiflora; however, R. multiflora had the highest root Na concentration followed by R. odorata. All rootstocks had higher Cl accumulation in all plant parts at elevated salinities, and no substantial differences in Cl concentrations in all plant parts existed among the rootstocks, except for leaf Cl concentration in R. multiflora, which was higher than those in the other two rootstocks. The elevated salinities of irrigation water reduced the relative chlorophyll concentration, measured as leaf SPAD readings, and maximal photochemical efficiency of photosystem II (PSII) and minimal fluorescence (F0)/maximum fluorescence (Fv/Fm), but the largest reduction in Fv/Fm was only 2.4%. Based on growth and visual quality, R. ×fortuniana was relatively more salt-tolerant than the other two rootstocks and R. odorata was slightly more salt-tolerant than R. multiflora. PMID:20148186

Different adaptation strategies of two citrus scion/rootstock combinations in response to drought stress

PubMed Central

Coelho Filho, Mauricio Antônio; Morillon, Raphaël; Bonatto, Diego; da Silva Gesteira, Abelmon

2017-01-01

Scion/rootstock interaction is important for plant development and for breeding programs. In this context, polyploid rootstocks presented several advantages, mainly in relation to biotic and abiotic stresses. Here we analyzed the response to drought of two different scion/rootstock combinations presenting different polyploidy: the diploid (2x) and autotetraploid (4x) Rangpur lime (Citrus limonia, Osbeck) rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis) scions, named V/2xRL and V/4xRL, respectively. Based on previous gene expression data, we developed an interactomic approach to identify proteins involved in V/2xRL and V/4xRL response to drought. A main interactomic network containing 3,830 nodes and 97,652 edges was built from V/2xRL and V/4xRL data. Exclusive proteins of the V/2xRL and V/4xRL networks (2,056 and 1,001, respectively), as well as common to both networks (773) were identified. Functional clusters were obtained and two models of drought stress response for the V/2xRL and V/4xRL genotypes were designed. Even if the V/2xRL plant implement some tolerance mechanisms, the global plant response to drought was rapid and quickly exhaustive resulting in a general tendency to dehydration avoidance, which presented some advantage in short and strong drought stress conditions, but which, in long terms, does not allow the plant survival. At the contrary, the V/4xRL plants presented a response which strong impacts on development but that present some advantages in case of prolonged drought. Finally, some specific proteins, which presented high centrality on interactomic analysis were identified as good candidates for subsequent functional analysis of citrus genes related to drought response, as well as be good markers of one or another physiological mechanism implemented by the plants. PMID:28545114

Preformation in vegetative buds of pistachio (Pistacia vera): relationship to shoot morphology, crown structure and rootstock vigor.

PubMed

Spann, Timothy M; Beede, Robert H; Dejong, Theodore M

2007-08-01

Effects of rootstock, shoot carbohydrate status, crop load and crown position on the number of preformed leaf primordia in the dormant terminal and lateral buds of mature and immature 'Kerman' pistachio (Pistacia vera L.) trees were investigated to determine if rootstock vigor is associated with greater shoot preformation. There was no significant variation in preformation related to the factors studied, suggesting strong genetic control of preformation in 'Kerman' pistachio. The growth differences observed among trees on different rootstocks were associated with greater stimulation of neoformed growth in trees on the more vigorous rootstocks. However, most annual extension growth in mature tree crowns was preformed, contrasting with the relatively high rate of neoformation found in young tree crowns. Large amounts of neoformed growth in young trees may allow the trees to become established quickly and secure resources, whereas predominantly preformed growth in mature trees may allow for continued crown expansion without outgrowing available resources. We hypothesized that the stimulation of neoformed growth by the more vigorous rootstocks is associated with greater resource uptake or transport, or both. Understanding the source of variation in shoot extension growth on different rootstocks has important implications for orchard management practices.

Rootstock-regulated gene expression patterns associated with fire blight resistance in apple

USDA-ARS?s Scientific Manuscript database

Background: Desirable apple varieties are clonally propagated by grafting vegetative scions onto rootstocks. Rootstocks influence many phenotypic traits of the scion, including resistance to pathogens such as Erwinia amylovora, which causes fire blight, the most serious bacterial disease of apple....

Apple rootstocks: history, physiology, management and breeding

USDA-ARS?s Scientific Manuscript database

For more than two millennia superior fruit tree genotypes have been grafted onto rootstocks to maintain the genetic identity of the desirable scions. Until the 20th century most fruit trees were grafted onto seedling rootstocks. Following the classification, evaluation and propagation of clonal root...

Identification of tree-crop rootstocks with resistance to Armillaria root disease.

USDA-ARS?s Scientific Manuscript database

Armillaria root disease attacks a broad range of tree crops in California. Instead of re-tooling ineffective conventional controls, namely soil fumigation, we focused on identification of Armillaria-resistant Juglans rootstocks, as part of a collaborative project to identify rootstocks with resistan...

Modifications of 'Gold Finger' Grape Berry Quality as Affected by the Different Rootstocks.

PubMed

Jin, Zhongxin; Sun, Hong; Sun, Tianyu; Wang, Qingjie; Yao, Yuxin

2016-06-01

Berry qualities of the grafted 'Gold Finger' grapevines were determined to evaluate the impacts of the resistant rootstocks on fruit quality. Compared to the own-rooted vines, berry and cluster weights and skin color were altered by the rootstocks to varying extents. The rootstock of 101-14M maintained TSS/TA and the contents of fructose, glucose, and sucrose, and SO4 decreased these parameters. 101-14M and 3309C increased and reduced the resveratrol content, respectively. SO4, 5BB, and 3309C decreased the total free amino acid content, along with the changes in amino acid composition. The amounts of aroma components were widely altered by the rootstocks. Additionally, a digital gene expression tag profiling revealed that the biological processes were largely altered by 3309C and 101-14M, including sugar, amino acid, and aroma metabolisms. In summary, the rootstock of 101-14M generally maintained berry quality, and SO4, 5BB, and 3309C imparted varying influences on different quality parameters.

Quality attributes of pistachio nuts as affected by rootstock and deficit irrigation.

PubMed

Carbonell-Barrachina, Ángel A; Memmi, Houssem; Noguera-Artiaga, Luis; Gijón-López, María del Carmen; Ciapa, Rafał; Pérez-López, David

2015-11-01

In this work, the influence of two regulated deficit irrigation (RDI) treatments and three different rootstocks on the quality of pistachios was evaluated by analyzing different parameters: morphological analysis, physicochemical analysis and sensory analysis. The results obtained in terms of the choice of rootstock revealed that Pistacia atlantica had increased production yields, nut weight, mineral content, higher intensities of characteristic sensory attributes and a higher degree of consumer satisfaction, than the other rootstocks studied. Moreover, the results established that the application of RDI on pistachio cultivation had no significant influence on production yield, weight, size, colour, water activity or mineral composition. Furthermore, T1 treatment (stem water potential < -1.3 MPa) resulted in higher intensities of characteristic sensory attributes and a greater level of satisfaction among international consumers. These results confirm that the application of deficit irrigation (T1) contributes to an increase in overall product quality. Furthermore, Pistacia atlantica rootstock provided better yield and quality than the other rootstocks studied. © 2014 Society of Chemical Industry.

Reaction of Prunus Rootstocks to Meloidogyne incognita and M. arenaria in Spain

PubMed Central

Marull, J.; Pinochet, J.; Verdejo-Lucas, S.; Soler, A.

1991-01-01

Prunus rootstocks were evaluated for their reaction to Meloidogyne incognita and M. arenaria. Most rootstocks were peach-almond hybrids of Spanish origin. In one experiment three selections of Garfi x Nemared (G x N) and Hansen-5 were highly resistant to M. incognita, but four other rootstocks were susceptible showing high galling indices and population increases. In two experiments with M. arenaria, the hybrid selections G x N nos. 1 and 9 were immune, GF-305 and Hansen-5 were resistant, but nine other rootstocks expressed various degrees of susceptibility. All Spanish rootstocks were susceptible to both Meloidogyne species except for the three G x N selections. The root-knot nematode resistant peach Nemared used as a male parent with Garfi was found to transmit a high degree of resistance to M. incognita and immunity to M. arenaria. Progenies of P. davidiana (Ga x D no. 3), a known source of resistance to root-knot nematodes, were susceptible. PMID:19283164

The relationship between root hydraulics and scion vigour across Vitis rootstocks: what role do root aquaporins play?

PubMed Central

McElrone, A. J.

2012-01-01

Vitis vinifera scions are commonly grafted onto rootstocks of other grape species to influence scion vigour and provide resistance to soil-borne pests and abiotic stress; however, the mechanisms by which rootstocks affect scion physiology remain unknown. This study characterized the hydraulic physiology of Vitis rootstocks that vary in vigour classification by investigating aquaporin (VvPIP) gene expression, fine-root hydraulic conductivity (Lp r), % aquaporin contribution to Lp r, scion transpiration, and the size of root systems. Expression of several VvPIP genes was consistently greater in higher-vigour rootstocks under favourable growing conditions in a variety of media and in root tips compared to mature fine roots. Similar to VvPIP expression patterns, fine-root Lp r and % aquaporin contribution to Lp r determined under both osmotic (Lp r Osm) and hydrostatic (Lp r Hyd) pressure gradients were consistently greater in high-vigour rootstocks. Interestingly, the % aquaporin contribution was nearly identical for Lp r Osm and Lp r Hyd even though a hydrostatic gradient would induce a predominant flow across the apoplastic pathway. In common scion greenhouse experiments, leaf area-specific transpiration (E) and total leaf area increased with rootstock vigour and were positively correlated with fine-root Lp r. These results suggest that increased canopy water demands for scion grafted onto high-vigour rootstocks are matched by adjustments in root-system hydraulic conductivity through the combination of fine-root Lp r and increased root surface area. PMID:23136166

NC-140 peach rootstock testing in 13 U.S. states

USDA-ARS?s Scientific Manuscript database

Eighteen Prunus rootstocks budded with ‘Redhaven’ peach were planted at 16 locations in North America in 2009. Fourth-year performance from 14 locations show that significant differences among rootstocks and sites were found for survival, root suckers, growth, bloom date, fruit maturity date, fruit ...

Efficient propagation of citrus rootstocks by stem cuttings

USDA-ARS?s Scientific Manuscript database

A simple multicomponent system is described that is effective for rapid propagation of a diversity of citrus rootstock genotypes by single node cuttings, including new hybrids and those that are most commonly used as rootstocks. Efficiency of this system for rooting shoot explants of six important r...

Phylogenetic Relationships Among Cucurbit Species Used as Rootstocks for Grafting Watermelon

USDA-ARS?s Scientific Manuscript database

There is an increased interest in the United States in grafting watermelon on cucurbit rootstocks to control soilborne diseases. Several cucurbit species including Lagenaria siceraria, Cucurbita spp. and Benincasa hispida (wax gourds) have been used in Asia as rootstocks for watermelon. In our pre...

Inheritance of graft compatibility in Douglas fir.

Treesearch

D.L. Copes

1973-01-01

Graft compatibility of genetically related and unrelated rootstock-scion combinations was compared. Scion clones were 75% compatible when grafted on half-related rootstocks but only 56% compatible when grafted on unrelated rootstocks. Most variance associated with graft incompatibility in Douglas-fir appears to be caused by multiple genes.

Grafting and Paladin Pic-21 for Nematode and Weed Management in Vegetable Production

PubMed Central

Kokalis-Burelle, Nancy; Butler, David M.; Hong, Jason C.; Bausher, Michael G.; McCollum, Greg; Rosskopf, Erin N.

2016-01-01

Two years of field trials conducted in a Meloidogyne incognita-infested field evaluated grafting and Paladin Pic-21 (dimethyl disulfide:chloropicrin [DMDS:Pic] 79:21) for root-knot nematode and weed control in tomato and melon. Tomato rootstocks evaluated were; ‘TX301’, ‘Multifort’, and ‘Aloha’. ‘Florida 47’ was the scion and the nongrafted control. A double crop of melon was planted into existing beds following tomato harvest. Melon rootstocks, C. metulifer and ‘Tetsukabuto’, were evaluated with nongrafted ‘Athena’ in year 1. In year 2, watermelon followed tomato with scion variety ‘Tri-X Palomar’ as the control and also grafted onto ‘Emphasis’ and ‘Strongtosa’ rootstocks. Four soil treatments were applied in fall both years under Canslit metalized film; Paladin Pic-21, methyl bromide:chloropicrin (MeBr:C33, 67:33), Midas (iodomethane:chloropicrin 50:50), and a herbicide-treated control. M. incognita J2 in soil were highest in herbicide control plots and nongrafted tomato. All soil treatments produced similar tomato growth, which was greater than the herbicide control. All treatments reduced M. incognita J2 in roots compared to the herbicide control. ‘Multifort’ rootstock produced the largest and healthiest roots; however, the number of M. incognita isolated from roots did not differ among the tomato rootstocks tested. Galling on tomato was highest in herbicide control plots and nongrafted plants. In melon, M. incognita J2 in soil did not differ among melon rootstocks, but numbers isolated from melon rootstocks increased in ‘Tetsukabuto’ compared with C. metuliferus. ‘Tetsukabuto’ were larger root systems than nongrafted ‘Athena’. All fumigants provided protection for all melon rootstocks against galling by M. incognita compared to the herbicide control. Galling on C. metuliferus rootstock was less in all fumigant treatments compared with nongrafted ‘Athena’ and ‘Tetsukabuto’. In watermelon, M. incognita in soil and roots did not differ among soil treatments or watermelon rootstocks, and yield was lower in both grafted rootstocks compared with the nongrafted control. All soil treatments increased average fruit weight of watermelon compared with the herbicide control, and provided effective weed control, keeping the most predominant weed, purple nutsedge (Cyperus rotundus L.), density at or below 1/m row. Grafting commercial scions onto M. incognita-resistant rootstocks has potential for nematode management combined with soil treatments or as a stand-alone component in crop production systems. PMID:28154429

Efficacy of rootstocks for control of Meloidogyne incognita on grafted tomato and cantaloupe

USDA-ARS?s Scientific Manuscript database

A microplot experiment was conducted to evaluate root-knot nematode (Meloidogyne incognita) resistance in rootstocks used for producing grafted tomato (Solanum esculentum) and muskmelon (Cucumis melo). Three tomato rootstocks including ‘TX301’ (Syngenta Seeds), ‘Multifort’ (De Ruiter Seeds), and ‘A...

MP-29, a clonal interspecific hybrid rootstock for peach

USDA-ARS?s Scientific Manuscript database

MP-29 rootstock has been jointly released for grower trial by the U.S. Department of Agriculture, Agricultural Research Service (Byron, GA) and Florida Agricultural Experiment Station. MP-29 is suggested for trial as a rootstock for peach (Prunus persica L. Batsch) varieties on Armillaria root rot ...

Apple replant disease and the –omics: interaction of apple rootstock metabolome and the soil microbiome

USDA-ARS?s Scientific Manuscript database

Apple replant disease (ARD) negatively impacts tree health and reduces crop yield in new orchard plantings. Use of tolerant rootstock cultivars can diminish the growth limiting effects of ARD; however specific rootstock attributes enabling ARD tolerance are not understood. Systems biology tools were...

Resistance of Some Vitis Rootstocks to Xiphinema index.

PubMed

Harris, A R

1983-07-01

Thirty-eight grapevine (Vitis spp.) rootstocks were screened in pots for resistance to the dagger nematode, Xiphinema index, from 1979 to 1981. Resistance ratings were based on visible root symptoms and on changes in the nematode populations over 16 months. Nineteen of the 23 Californian hybrid rootstocks tested were resistant, as were 'Harmony',' 'Freedom,' 'Schwarzmann,' and '3309.' Two hybrids of V. rufotomentosa, '171-52' and '176-9,' were possibly immune to X. index. The rootstocks 'ARG 1,' ' 110 R,' '1202,' and '1616,' which are used commercially for phylloxera resistance were susceptible.

Proteomic study participating the enhancement of growth and salt tolerance of bottle gourd rootstock-grafted watermelon seedlings.

PubMed

Yang, Yanjuan; Wang, Liping; Tian, Jing; Li, Jing; Sun, Jin; He, Lizhong; Guo, Shirong; Tezuka, Takafumi

2012-09-01

An insertion grafting technique to do research on salt tolerance was applied using watermelon (Citrullus lanatus [Thunb.] Mansf. cv. Xiuli) as a scion and bottle gourd (Lagenaria siceraria Standl. cv. Chaofeng Kangshengwang) as a rootstock. Rootstock-grafting significantly relieved the inhibition of growth and photosynthesis induced by salt stress in watermelon plants. Proteomic analysis revealed 40 different expressed proteins in response to rootstock-grafting and/or salt stress. These proteins were involved in Calvin cycle, amino acids biosynthesis, carbohydrate and energy metabolism, ROS defense, hormonal biosynthesis and signal transduction. Most of these proteins were up-regulated by rootstock-grafting and/or susceptible to salt stress. The enhancement of the metabolic activities of Calvin cycle, biosynthesis of amino acids, carotenoids and peroxisomes, glycolytic pathway and tricarboxylic acid cycle will probably contribute to intensify the biomass and photosynthetic capacity in rootstock-grafted seedlings under condition without salt. The accumulation of key enzymes included in these biological processes described above seems to play an important role in the enhancement of salt tolerance of rootstock-grafted seedlings. Furthermore, leucine-rich repeat transmembrane protein kinase and phospholipase may be involved in transmitting the internal and external stimuli induced by grafting and/or salt stress. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Performance of Prunus rootstocks in the 2001 NC-140 peach trial

USDA-ARS?s Scientific Manuscript database

Fourteen Prunus rootstock cultivars and selections budded with either ‘Redtop’, ‘Redhaven’ or ‘Cresthaven’ peach were planted at 11 locations in North America in 2001 in a randomized block design with a tree spacing of 5 by 6 m and 8 replicates. These rootstocks included three peach seedling rootst...

Tree and root architecture of Malus sieversii seedlings for rootstock breeding

USDA-ARS?s Scientific Manuscript database

The foundation of a successful apple orchard is in large part the rootstock used to establish the trees in that orchard. Apple rootstocks can impart several important architectural tree characters to the scion, among which are reduction in tree size and early production of flowers/fruit. It is pro...

Prunus rootstocks influence stem water potential, C/N ratio and shoot ash content in peach

USDA-ARS?s Scientific Manuscript database

Many peach rootstocks have been released in recent years with limited information about their physiological effects on scion vigor and productivity. In this study, two trials were established with ‘Redhaven’ on 9 (planted 2006) and 18 (planted 2009) rootstock cultivars at the Musser Fruit Research ...

CROWN GALL INCIDENCE: SEEDLING PARADOX WALNUT ROOTSTOCK VERSUS OWN-ROOTED ENGLISH WALNUT TREES

USDA-ARS?s Scientific Manuscript database

Seedling Paradox (Juglans hindsii x J. regia) has been the rootstock of choice for English walnut in California because of its vigor and greater tolerance of wet soil conditions. However, seedling Paradox rootstock is highly susceptible to crown gall, a disease caused by the soil-borne bacterium Agr...

First report of root rot caused by Phytopythium helicoides on pistachio rootstock in California

USDA-ARS?s Scientific Manuscript database

We examined pathogenicity of Phytopythium helicoides on UCB-1 rootstock to investigate its role in root disease and collapse observed on potted pistachio plants. Approximately 25 potted 2-year-old pistachio rootstock trees in a Kern County, CA, research plot maintained outdoors and irrigated to cont...

Effects of apple (Malus x domestica) rootstocks on scion performance and hormone concentration

USDA-ARS?s Scientific Manuscript database

Rootstocks can influence the productivity and profitability of an orchard in a very significant way. Dwarfing rootstocks had a large impact in making possible the high-density orchards that have been planted during the last 15 years. However, there is a serious threat to high-density apple orchards,...

Apple endophytic microbiota of different rootstock/scion combinations suggests a genotype-specific influence

USDA-ARS?s Scientific Manuscript database

The present study described the microbiota associated with three apple varieties, ‘Royal Gala’, ‘Golden Delicious’, and ‘Honey Crisp’, and two rootstocks, M.9, and M.M.111. The objectives were to 1) determine if the microbiota differs in different rootstocks and apple varieties, and 2) determine if...

Rootstock performance in the 2009 NC-140 peach trial across 11 states

USDA-ARS?s Scientific Manuscript database

From 14 to 18 Prunus rootstocks budded with ‘Redhaven’ peach were planted at 16 locations in North America in 2009. Seven-year performance from 12 remaining locations in 11 states showed that significant differences among rootstocks and sites were found for survival, root suckers, growth, bloom dat...

Rootstock mass of coppiced Platanus occidentalis as affected by spacing and rotation length

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

Steinbeck, K.; Nwoboshi, L.C.

1980-01-01

The root mass per unit land area for Platanus occidentalis was determined 9 years after planting 1-0 seedlings. Trees had been planted at 0.3 X 1.2, 0.6 X 1.2 and 1.2 X 1.2 m spacings and coppiced after two growing seasons in the field. Rotations of 1, 2, and 7 years were then imposed. Rootstocks coppiced annually had significantly less rootstock mass (16.0 tons/ha) than those harvested on longer cycles. No significant difference was found between the 2- and 7-year rotations, which averaged 22.8 and 25.2 tons of dry rootstock mass per hectare, respectively. Spacing did not affect rootstock massmore » per unit land area. Rotations of 2 years or longer and relatively wide spacings are recommended for short rotation forestry.« less

Ion homeostasis, osmoregulation, and physiological changes in the roots and leaves of pistachio rootstocks in response to salinity.

PubMed

Akbari, Mohammad; Mahna, Nasser; Ramesh, Katam; Bandehagh, Ali; Mazzuca, Silvia

2018-03-12

Pistachio, one of the important tree nuts, is cultivated in arid and semi-arid regions where salinity is the most common abiotic stress encountered by this tree. However, the mechanisms underlying salinity tolerance in this plant are not well understood. In the present study, five 1-year-old pistachio rootstocks (namely Akbari, Badami, Ghazvini, Kale-Ghouchi, and UCB-1) were treated with four saline water regimes (control, 8, 12, and 16 dS m -1 ) for 100 days. At high salinity level, all rootstocks showed decreased relative water content (RWC), total chlorophyll content (TCHC), and carotenoids in the leaf, while ascorbic acid (AsA) and total soluble proteins (TSP) were reduced in both leaf and root organs. In addition, the total phenolic compounds (TPC), proline, glycine betaine, total soluble carbohydrate (TSC), and H 2 O 2 content increased under salinity stress in all studied rootstocks. Three different ion exclusion strategies were observed in the studied rootstocks: (i) Na + exclusion in UCB-1, because most of its Na + is retained in the roots; (ii) Cl - exclusion in Badami, in which most of its Cl - remained in the roots; and (iii) similar concentrations of Na + and Cl - were observed in the leaves and roots of Ghazvini, Akbari, and Kale-Ghouchi. Transport capacity (ST value) of K + over Na + from the roots to the leaves was more observable in UCB-1 and Ghazvini. Overall, the root system cooperated more effectively in UCB-1 and Badami for retaining and detoxifying an excessive amount of Na + and Cl - . The results presented here provide important inputs to better understand the salt tolerance mechanism in a tree species for developing more salt-tolerant genotypes. Based on the results obtained here, the studied rootstocks from tolerant to susceptible are arranged as follows: UCB-1 > Badami > Ghazvini > Kale-Ghouchi > Akbari.

Chemical characterization of Azadirachta indica grafted on Melia azedarach and analyses of azadirachtin by HPLC-MS-MS (SRM) and meliatoxins by MALDI-MS.

PubMed

Forim, Moacir Rossi; Cornélio, Vivian Estevam; da Silva, M Fátima das G F; Rodrigues-Filho, Edson; Fernandes, João B; Vieira, Paulo C; Matinez, Sueli Souza; Napolitano, Michael P; Yost, Richard A

2010-01-01

Melia azedarach adapted to cool climates was selected as rootstocks for vegetative propagation of Azadirachta indica. Cleft grafting of A. indica on M. azedarach rootstock showed excellent survival. Little is known about the chemistry of grafting. The roots, stems, leaves and seeds of this graft were examined in order to verify if grafted A. indica would produce limonoids different from those found in non-grafted plants. Intact matured fruits were also studied to verify if they were free of meliatoxins. After successive chromatographic separations the extracts afforded several limonoids. HPLC-MS/MS and MALDI-MS were used to develop sensitive methods for detecting azadirachtin on all aerial parts of this graft and meliatoxins in fruits, respectively. The stem afforded the limonoid salannin, which was previously found in the oil seeds of A. indica. Salannin is also found in the root bark of M. azedarach. Thus, the finding of salannin in this study suggests that it could have been translocated from the M. azedarach rootstock to the A. indica graft. HPLC-MS/MS analyses showed that azadirachtin was present in all parts of the fruits, stem, flowers and root, but absent in the leaves. The results of MALDI-MS analyses confirmed the absence of meliatoxins in graft fruits. This study showed that A. indica grafted onto M. azedarach rootstock produces azadirachtin, and also that its fruits are free of meliatoxins from rootstocks, confirming that this graft forms an excellent basis for breeding vigorous Neem trees in cooler regions.

Notice to fruit growers and nurserymen relative to the naming and release of the US-942 citrus roostock

USDA-ARS?s Scientific Manuscript database

A new citrus rootstock, US-942 is hereby released by the Agricultural Research Service to nurserymen and growers. This rootstock selection originated from a cross of Sunki mandarin × Flying Dragon Trifoliate Orange. US-942 rootstock yields semi-dwarf and productive trees that have excellent fruit ...

Yield, fruit quality traits and leaf nutrient concentration of sapodilla cv ‘Prolific’ grafted onto 16 rootstocks in Puerto Rico

USDA-ARS?s Scientific Manuscript database

Research on sapodilla has been very limited. A field study was conducted to determine the yield potential, fruit quality traits, leaf nutrient composition and scion/rootstock compatibility of cultivar ‘Prolific’ grafted onto 16 sapodilla rootstocks. For this purpose cultivars ‘Adelaide’, ‘Arcilago’...

Apple endophytic microbiota of different rootstock/scion combinations suggests a genotype-specific influence.

PubMed

Liu, Jia; Abdelfattah, Ahmed; Norelli, John; Burchard, Erik; Schena, Leonardo; Droby, Samir; Wisniewski, Michael

2018-01-27

High-throughput amplicon sequencing spanning conserved portions of microbial genomes (16s rRNA and ITS) was used in the present study to describe the endophytic microbiota associated with three apple varieties, "Royal Gala," "Golden Delicious," and "Honey Crisp," and two rootstocks, M.9 and M.M.111. The objectives were to (1) determine if the microbiota differs in different rootstocks and apple varieties and (2) determine if specific rootstock-scion combinations influence the microbiota composition of either component. Results indicated that Ascomycota (47.8%), Zygomycota (31.1%), and Basidiomycota (11.6%) were the dominant fungal phyla across all samples. The majority of bacterial sequences were assigned to Proteobacteria (58.4%), Firmicutes (23.8%), Actinobacteria (7.7%), Bacteroidetes (2%), and Fusobacteria (0.4%). Rootstocks appeared to influence the microbiota of associated grafted scion, but the effect was not statistically significant. Pedigree also had an impact on the composition of the endophytic microbiota, where closely-related cultivars had a microbial community that was more similar to each other than it was to a scion cultivar that was more distantly-related by pedigree. The more vigorous rootstock (M.M.111) was observed to possess a greater number of growth-promoting bacterial taxa, relative to the dwarfing rootstock (M.9). The mechanism by which an apple genotype, either rootstock or scion, has a determinant effect on the composition of a microbial community is not known. The similarity of the microbiota in samples with a similar pedigree suggests the possibility of some level of co-evolution or selection as proposed by the "holobiont" concept in which metaorganisms have co-evolved. Clearly, however, the present information is only suggestive, and a more comprehensive analysis is needed.

Evaluation, grafting success and field establishment of cashew rootstock as influenced by VAM fungi.

PubMed

Lakshmipathy, R; Balakrishna, A N; Bagyaraj, D J; Sumana, D A; Kumar, D P

2004-11-01

Seven isolates of vesicular arbuscular mycorrhizal (VAM) fungi were isolated from cashew rhizosphere soil of different cashew growing regions of South India. These seven isolates along with two more VAM fungi namely Acaulospora laevis and Glomus mosseae, which were found to be better symbionts for cashew during our earlier study were used to study their effectiveness on the growth and nutrition of cashew rootstock Ullal-1. Four promising VAM fungi were selected based on this study. Rootstocks inoculated with these four fungi were evaluated for their vigour through grafting success, using Ullal-3 cashew variety as scion. Grafting success was more in rootstocks inoculated with A. laevis and one of local isolates Glomus etunicatum. Grafts with rootstock treated with G. etunicatum and A. laevis survived and performed better when planted in the field compared to the uninoculated and other VAM fungal treatments.

Rootstock and fruit canopy position affect peach [Prunus persica (L.) Batsch] (cv. Rich May) plant productivity and fruit sensorial and nutritional quality.

PubMed

Gullo, Gregorio; Motisi, Antonio; Zappia, Rocco; Dattola, Agostino; Diamanti, Jacopo; Mezzetti, Bruno

2014-06-15

The right combination of rootstock and training system is important for increased yield and fruit sensorial and nutritional homogeneity and quality with peach [Prunus persica (L.) Batsch]. We investigated the effects of rootstock and training system on these parameters, testing the effect of vigorous GF677 and weaker Penta rootstock on 'Rich May' peach cultivar. Fruit position effects regarding photosynthetically active radiation availability, along the canopy profile using the Y training system, were investigated. The positive relationships between total polyphenols content and antioxidant capacity according to canopy vigour and architecture were determined for the two scion/stock combinations. Changes in fruit epicarp colour and content of bioactive compounds were also determined. Lower-vigour trees from Penta rootstock grafting yielded larger fruit with improved skin overcolour, and greater total polyphenols content and antioxidant capacity. GF677 rootstock produced more vigorous trees with fruit with lower sensorial and nutritional parameters. Canopy position strongly affects fruit sensorial and nutritional qualities. These data define potential for improvements to peach production efficiency and fruit quality, particularly for southern Europe peach cultivation conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Resistance of Grape Rootstocks to Plant-parasitic Nematodes.

PubMed

Ferris, H; Zheng, L; Walker, M A

2012-12-01

Candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to Meloidogyne pathotypes and to Xiphinema index in Muscadinia rotundifolia and Vitis species native to North America. Based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. After a 15-year screening process, 13 selections emerged with either almost complete or complete combined resistance to M. incognita Race 3, M. incognita pathotype Harmony C, M. arenaria pathotype Harmony A, and X. index, important nematode pests of grapevines. Durability of this broad resistance was tested by challenging the selections with the target nematodes in combination and with the target nematodes in combinations with species not included in the screening process. Durability of resistance of the candidate rootstocks was also tested by exposure to the nematode communities of infested field soils from different locations. Breadth of resistance was determined on the basis of their host status to non-target nematodes, including Mesocriconema xenoplax, Pratylenchus vulnus, Tylenchulus semipenetrans and Paratylenchus hamatus. After a total of 204 separate trials, the rootstocks were released to the grape industry as UCD GRN1, UCD GRN2, UCD GRN3, UCD GRN4, and UCD GRN5. We provide a compilation of current knowledge of the host status of these five newly released rootstocks and of 27 other rootstock cultivars to plant-parasitic nematodes.

Resistance of Grape Rootstocks to Plant-parasitic Nematodes

PubMed Central

Ferris, H.; Zheng, L.; Walker, M. A.

2012-01-01

Candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to Meloidogyne pathotypes and to Xiphinema index in Muscadinia rotundifolia and Vitis species native to North America. Based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. After a 15-year screening process, 13 selections emerged with either almost complete or complete combined resistance to M. incognita Race 3, M. incognita pathotype Harmony C, M. arenaria pathotype Harmony A, and X. index, important nematode pests of grapevines. Durability of this broad resistance was tested by challenging the selections with the target nematodes in combination and with the target nematodes in combinations with species not included in the screening process. Durability of resistance of the candidate rootstocks was also tested by exposure to the nematode communities of infested field soils from different locations. Breadth of resistance was determined on the basis of their host status to non-target nematodes, including Mesocriconema xenoplax, Pratylenchus vulnus, Tylenchulus semipenetrans and Paratylenchus hamatus. After a total of 204 separate trials, the rootstocks were released to the grape industry as UCD GRN1, UCD GRN2, UCD GRN3, UCD GRN4, and UCD GRN5. We provide a compilation of current knowledge of the host status of these five newly released rootstocks and of 27 other rootstock cultivars to plant-parasitic nematodes. PMID:23482972

Phenotypic variation among trees in a population of a Pistacia atlantica X P. integerrima cross sold as UCB-1 rootstock for grafting P. vera (pistachio) cultivars

USDA-ARS?s Scientific Manuscript database

UCB-1 is widely used in California as a pistachio rootstock because of its Verticillium resistance, salt and cold tolerance, and vigor. It can grow in most locations in California. However, significant variation exists in the phenotypic performance of trees grafted to seedling UCB-1 rootstocks. In J...

Grapevine rootstocks shape underground bacterial microbiome and networking but not potential functionality.

PubMed

Marasco, Ramona; Rolli, Eleonora; Fusi, Marco; Michoud, Grégoire; Daffonchio, Daniele

2018-01-03

The plant compartments of Vitis vinifera, including the rhizosphere, rhizoplane, root endosphere, phyllosphere and carposphere, provide unique niches that drive specific bacterial microbiome associations. The majority of phyllosphere endophytes originate from the soil and migrate up to the aerial compartments through the root endosphere. Thus, the soil and root endosphere partially define the aerial endosphere in the leaves and berries, contributing to the terroir of the fruit. However, V. vinifera cultivars are invariably grafted onto the rootstocks of other Vitis species and hybrids. It has been hypothesized that the plant species determines the microbiome of the root endosphere and, as a consequence, the aerial endosphere. In this work, we test the first part of this hypothesis. We investigate whether different rootstocks influence the bacteria selected from the surrounding soil, affecting the bacterial diversity and potential functionality of the rhizosphere and root endosphere. Bacterial microbiomes from both the root tissues and the rhizosphere of Barbera cultivars, both ungrafted and grafted on four different rootstocks, cultivated in the same soil from the same vineyard, were characterized by 16S rRNA high-throughput sequencing. To assess the influence of the root genotype on the bacterial communities' recruitment in the root system, (i) the phylogenetic diversity coupled with the predicted functional profiles and (ii) the co-occurrence bacterial networks were determined. Cultivation-dependent approaches were used to reveal the plant-growth promoting (PGP) potential associated with the grafted and ungrafted root systems. Richness, diversity and bacterial community networking in the root compartments were significantly influenced by the rootstocks. Complementary to a shared bacterial microbiome, different subsets of soil bacteria, including those endowed with PGP traits, were selected by the root system compartments of different rootstocks. The interaction between the root compartments and the rootstock exerted a unique selective pressure that enhanced niche differentiation, but rootstock-specific bacterial communities were still recruited with conserved PGP traits. While the rootstock significantly influences the taxonomy, structure and network properties of the bacterial community in grapevine roots, a homeostatic effect on the distribution of the predicted and potential functional PGP traits was found.

Hormonal and Nutritional Features in Contrasting Rootstock-mediated Tomato Growth under Low-phosphorus Nutrition.

PubMed

Martínez-Andújar, Cristina; Ruiz-Lozano, Juan M; Dodd, Ian C; Albacete, Alfonso; Pérez-Alfocea, Francisco

2017-01-01

Grafting provides a tool aimed to increase low-P stress tolerance of crops, however, little is known about the mechanism (s) by which rootstocks can confer resistance to P deprivation. In this study, 4 contrasting groups of rootstocks from different genetic backgrounds ( Solanum lycopersicum var. cerasiforme and introgression and recombinant inbred lines derived from the wild relatives S. pennellii and S. pimpinellifolium ) were grafted to a commercial F1 hybrid scion and cultivated under control (1 mM, c ) and P deficient (0.1 mM, p ) conditions for 30 days, to analyze rootstocks-mediated traits that impart low ( L , low shoot dry weight, SDW) or high ( H , high SDW) vigor. Xylem sap ionic and hormonal anlyses leaf nutritional status suggested that some physiological traits can explain rootstocks impacts on shoot growth. Although xylem P concentration increased with root biomass under both growing conditions, shoot biomass under low-P was explained by neither changes in root growth nor P transport and assimilation. Indeed, decreased root P export only explained the sensitivity of the HcLp rootstocks, while leaf P status was similarly affected in all graft combinations. Interestingly, most of the nutrients analyzed in the xylem sap correlated with root biomass under standard fertilization but only Ca was consistently related to shoot biomass under both control and low-P, suggesting an important role for this nutrient in rootstock-mediated vigor. Moreover, foliar Ca, S, and Mn concentrations were (i) specifically correlated with shoot growth under low-P and (ii) positively and negatively associated to the root-to-shoot transport of the cytokinin trans -zeatin ( t -Z) and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), respectively. Indeed, those hormones seem to play an antagonistic positive ( t -Z) and negative (ACC) role in the rootstock-mediated regulation of shoot growth in response to P nutrition. The use of Hp -type rootstocks seems to enhance P use efficiency of a commercial scion variety, therefore could potentially be used for increasing yield and agronomic stability under low P availability.

Genetic control of pear rootstock-induced dwarfing and precocity is linked to a chromosomal region syntenic to the apple Dw1 loci.

PubMed

Knäbel, Mareike; Friend, Adam P; Palmer, John W; Diack, Robert; Wiedow, Claudia; Alspach, Peter; Deng, Cecilia; Gardiner, Susan E; Tustin, D Stuart; Schaffer, Robert; Foster, Toshi; Chagné, David

2015-09-22

The vigour and precocity of trees highly influences their efficiency in commercial production. In apple, dwarfing rootstocks allow high-density plantings while their precocious flowering enables earlier fruit production. Currently, there is a lack of pear (Pyrus communis L.) rootstocks that are equivalent to the high yielding apple rootstock 'M9'. For the efficient breeding of new Pyrus rootstocks it is crucial to understand the genetic determinants of vigour control and precocity. In this study we used quantitative trait loci (QTLs) analysis to identify genetic loci associated with the desired traits, using a segregating population of 405 F1 P. communis seedlings from a cross between 'Old Home' and 'Louise Bonne de Jersey' (OHxLBJ). The seedlings were grafted as rootstocks with 'Doyenne du Comice' scions and comprehensively phenotyped over four growing seasons for traits related to tree architecture and flowering, in order to describe the growth of the scions. A high density single nucleotide polymorphism (SNP)-based genetic map comprising 597 polymorphic pear and 113 apple markers enabled the detection of QTLs influencing expression of scion vigour and precocity located on linkage groups (LG)5 and LG6 of 'Old Home'. The LG5 QTL maps to a position that is syntenic to the apple 'Malling 9' ('M9') Dw1 locus at the upper end of LG5. An allele of a simple sequence repeat (SSR) associated with apple Dw1 segregated with dwarfing and precocity in pear and was identified in other pear germplasm accessions. The orthology of the vigour-controlling LG5 QTL between apple and pear raises the possibility that the dwarfing locus Dw1 arose before the divergence of apple and pear, and might therefore be present in other Rosaceae species. We report the first QTLs associated with vigour control and flowering traits in pear rootstocks. Orthologous loci were found to control scion growth and precocity in apple and pear rootstocks. The application of our results may assist in the breeding process of a pear rootstock that confers both vigour control and precocity to the grafted scion cultivar.

Host Range of a Population of Pratylenchus vulnus in Commercial Fruit, Nut, Citrus, and Grape Rootstocks in Spain.

PubMed

Pinochet, J; Verdejo, S; Soler, A; Canals, J

1992-12-01

In a host-range study carried out under greenhouse conditions, a total of 37 commercial fruit tree, grape, and citrus rootstocks were tested for their reaction to a population of the lesion nematode, Pratylenchus vulnus, in Spain. Twenty-five rootstocks had a Pf/Pi > 1.5. These included almond (Desmayo Rojo, 1143), apple (EM-9, EM-106), avocado (Hass), cherry (Santa Lucia 64, Camil, M x M 14, Masto de Montafiana), grape (41-B, Fercal, Ritcher 110), hazelnut (Pauetet), loquat (Nadal), peach (Montclar, GF-305), pear (OHF-333), pistachio (P. atlantica, P. vera, P. terebinthus), plum (San Julian 655-2, Montizo, Pixy, Myrobalan 605), and walnut (Serf). The peach rootstock Nemaguard and the grape 161-49 had Pf/Pi between 1.0 and 1.5 (slightly higher than inoculation level). All the tested citrus (Alemow, rough lemon, Carrizo citrange, sour orange, Troyer citrange, Citrumelo), plus three grape (SO4, Vitis rupestris, 1103-P), and the olive rootstock Arbequina had a Pf/Pi < 1.0.

Some seasonal carbohydrate fluctuations in coppiced rootstocks of Platanus occidentalis

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

Blum, M.R.; Steinbeck, K.

Carbohydrate concentrations were determined in 11-year-old rootstocks of American sycamore (Platanus occidentalis) which had been coppiced on one- or two-year rotations for the preceding eight years. Sixty rootstocks were destructively sampled periodically between September 1976 and April 1977. Root starch concentrations declined erratically from 21 percent of dry weight in autumn to 14 percent by late April. Sugar levels rose from 1.5 percent in autumn to 5 percent in winter and declined to 3 percent in spring. Considerable variation in root starch levels from tree to tree was observed, and differences in starch and sugar concentrations between rootstocks coppiced onmore » an annual or biannual basis were unimportant. These data suggest that while differences in above-ground biomass yields encountered in short rotation coppice forestry are not due to differences in rootstocks carbohydrate concentrations, the total quantity of reserve carbohydrate stored in a root system is probably a controlling factor for sprout regrowth potential.« less

The effect of water stress on some morphological, physiological, and biochemical characteristics and bud success on apple and quince rootstocks.

PubMed

Bolat, Ibrahim; Dikilitas, Murat; Ercisli, Sezai; Ikinci, Ali; Tonkaz, Tahsin

2014-01-01

The effects of different water stress (control, medium, and severe) on some morphological, physiological, and biochemical characteristics and bud success of M9 apple and MA quince rootstocks were determined. The results showed that water stress significantly affected most morphological, physiological, and biochemical characteristics as well as budding success on the both rootstocks. The increasing water stress decreased the relative shoot length, diameter, and plant total fresh and dry weights. Leaf relative water content and chlorophyll index decreased while electrolyte leakage increased with the increase of water stress in both rootstocks. An increase in water stress also resulted in reduction in budding success in Vista Bella/M9 (79.33% and 46.67%) and Santa Maria/MA (70.33% and 15.33%) combinations. However, the water stress in Santa Maria/MA was more prominent. The increase in water stress resulted in higher peroxidase activities as well as phenol contents in both rootstocks. Although catalase activity, anthocyanin, and proline contents increased with the impact of stress, this was not statistically significant. The results suggest that the impact of stress increased with the increase of water stress; therefore, growers should be careful when using M9 and MA rootstocks in both nursery and orchards where water scarcity is present.

Transgene mobilization and regulatory uncertainty for non-GE fruit products of transgenic rootstocks.

PubMed

Haroldsen, Victor M; Chi-Ham, Cecilia L; Bennett, Alan B

2012-10-31

Genetically engineered (GE) rootstocks may offer some advantages for biotechnology applications especially in woody perennial crops such as grape or walnut. Transgrafting combines horticultural grafting practices with modern GE methods for crop improvement. Here, a non-GE conventional scion (upper stem portion) is grafted onto a transgenic GE rootstock. Thus, the scion does not contain the genetic modification present in the rootstock genome. We examined transgene presence in walnut and tomato GE rootstocks and non-GE fruit-bearing scions. Mobilization of transgene DNA, protein, and mRNA across the graft was not detected. Though transgenic siRNA mobilization was not observed in grafted tomatoes or walnut scions, transgenic siRNA signal was detected in walnut kernels. Prospective benefits from transgrafted plants include minimized risk of GE pollen flow (Lev-Yadun and Sederoff, 2001), possible use of more than one scion per approved GE rootstock which could help curb the estimated US$136 million (CropLife International, 2011) cost to bring a GE crop to international markets, as well as potential for improved consumer and market acceptance since the consumable product is not itself GE. Thus, transgrafting provides an alternative option for agricultural industries wishing to expand their biotechnology portfolio. Copyright © 2012 Elsevier B.V. All rights reserved.

Soil Temperature Effects on the Interaction of Grape Rootstocks and Plant-parasitic Nematodes.

PubMed

Ferris, H; Zheng, L; Walker, M A

2013-03-01

Resistance to Meloidogyne spp. in commonly used resistant grape rootstocks is slightly compromised at soil temperatures above 27°C. Newly released UCD-GRN series rootstocks, which have broad nematode resistance, exhibit trace infections by Meloidogyne spp. at elevated temperature. Pathotypes of M. incognita and M. arenaria that are virulent on 'Harmony' rootstock, as well as M. incognita Race 3, which is avirulent on 'Harmony', failed to produce egg masses on the UCD-GRN series rootstocks and other resistant selections at 24°C. At 27°C and above, there was increased nematode galling and egg mass production; at 30°C, egg mass production levels of M. incognita Race 3 on 'Harmony' were up to 12% of that on susceptible 'Colombard' while reproduction of the virulent pathotypes on the UCD-GRN series was less than 5% of that on 'Colombard'. Resistance of several of the parental genotypes of the UCD-GRN rootstock series was slightly compromised at soil temperatures of 30°C and above; however, others maintained their resistance to even the virulent M. arenaria pathotype A at high temperatures. Effects of high temperature on resistance to Xiphinema index could not be assessed because of temperature sensitivity of the nematodes while resistance to Mesocriconema xenoplax was not compromised at high soil temperature. Resistance to Meloidogyne spp. in the UCD-GRN series rootstocks was not compromised when plants and nematodes were subjected to cyclical high and low temperature conditions, indicating that once initiated, the resistance mechanism is not reversed.

Soil Temperature Effects on the Interaction of Grape Rootstocks and Plant-parasitic Nematodes

PubMed Central

Ferris, H.; Zheng, L.; Walker, M. A.

2013-01-01

Resistance to Meloidogyne spp. in commonly used resistant grape rootstocks is slightly compromised at soil temperatures above 27°C. Newly released UCD-GRN series rootstocks, which have broad nematode resistance, exhibit trace infections by Meloidogyne spp. at elevated temperature. Pathotypes of M. incognita and M. arenaria that are virulent on ‘Harmony’ rootstock, as well as M. incognita Race 3, which is avirulent on ‘Harmony’, failed to produce egg masses on the UCD-GRN series rootstocks and other resistant selections at 24°C. At 27°C and above, there was increased nematode galling and egg mass production; at 30°C, egg mass production levels of M. incognita Race 3 on ‘Harmony’ were up to 12% of that on susceptible ‘Colombard’ while reproduction of the virulent pathotypes on the UCD-GRN series was less than 5% of that on ‘Colombard’. Resistance of several of the parental genotypes of the UCD-GRN rootstock series was slightly compromised at soil temperatures of 30°C and above; however, others maintained their resistance to even the virulent M. arenaria pathotype A at high temperatures. Effects of high temperature on resistance to Xiphinema index could not be assessed because of temperature sensitivity of the nematodes while resistance to Mesocriconema xenoplax was not compromised at high soil temperature. Resistance to Meloidogyne spp. in the UCD-GRN series rootstocks was not compromised when plants and nematodes were subjected to cyclical high and low temperature conditions, indicating that once initiated, the resistance mechanism is not reversed. PMID:23589660

Responses of grapevine rootstocks to drought through altered root system architecture and root transcriptomic regulations.

PubMed

Yıldırım, Kubilay; Yağcı, Adem; Sucu, Seda; Tunç, Sümeyye

2018-06-01

Roots are the major interface between the plant and various stress factors in the soil environment. Alteration of root system architecture (RSA) (root length, spread, number and length of lateral roots) in response to environmental changes is known to be an important strategy for plant adaptation and productivity. In light of ongoing climate changes and global warming predictions, the breeding of drought-tolerant grapevine cultivars is becoming a crucial factor for developing a sustainable viticulture. Root-trait modeling of grapevine rootstock for drought stress scenarios, together with high-throughput phenotyping and genotyping techniques, may provide a valuable background for breeding studies in viticulture. Here, tree grafted grapevine rootstocks (110R, 5BB and 41B) having differential RSA regulations and drought tolerance were investigated to define their drought dependent root characteristics. Root area, root length, ramification and number of root tips reduced less in 110R grafted grapevines compared to 5BB and 41B grafted ones during drought treatment. Root relative water content as well as total carbohydrate and nitrogen content were found to be much higher in the roots of 110R than it was in the roots of other rootstocks under drought. Microarray-based root transcriptome profiling was also conducted on the roots of these rootstocks to identify their gene regulation network behind drought-dependent RSA alterations. Transcriptome analysis revealed totally 2795, 1196 and 1612 differentially expressed transcripts at the severe drought for the roots of 110R, 5BB and 41B, respectively. According to this transcriptomic data, effective root elongation and enlargement performance of 110R were suggested to depend on three transcriptomic regulations. First one is the drought-dependent induction in sugar and protein transporters genes (SWEET and NRT1/PTR) in the roots of 110R to facilitate carbohydrate and nitrogen accumulation. In the roots of the same rootstock, expression increase in osmolyte producer genes revealed another transcriptomic regulation enabling effective root osmotic adjustment under drought stress. The third mechanism was linked to root suberization with upregulation of transcripts functional in wax producing enzymes (Caffeic acid 3-O-methyltransferase, Eceriferum3, 3-ketoacyl-CoAsynthase). These three transcriptomic regulations were suggested to provide essential energy and water preservation to the roots of 110R for its effective RSA regulation under drought. This phenotypic and genotypic knowledge could be used to develop root-dependent drought tolerant grapevines in breeding programs and could facilitate elucidation of genetic regulations behind RSA alteration in other plants. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Regulation of Nitrate Transport in Citrus Rootstocks Depending on Nitrogen Availability

PubMed Central

Cerezo, Miguel; Camañes, Gemma; Flors, Víctor; Primo-Millo, Eduardo

2007-01-01

Previously, we reported that in Citrus plants, nitrate influx through the plasmalemma of roots cells follows a biphasic pattern, suggesting the existence of at least two different uptake systems, a high and low affinity transport system (HATS and LATS, respectively). Here, we describe a novel inducible high affinity transport system (iHATS). This new nitrate transport system has a high capacity to uptake nitrate in two different Citrus rootstocks (Cleopatra mandarin and Troyer citrange). The iHATS was saturable, showing higher affinity than constitutive high affinity transport system (cHATS) to the substrate NO3−. The Vmax for this saturable component iHATS was higher than cHATS, reaching similar values in both rootstocks. Additionally, we studied the regulation of root NO3− uptake mediated by both HATS (iHATS and cHATS) and LATS. In both rootstocks, cHATS is constitutive and independent of N-status. Concerning the regulation of iHATS, this system is upregulated by NO3− and down-regulated by the N status and by NO3− itself when plants are exposed to it for a longer period of time. LATS in Cleopatra mandarin and Troyer citrange rootstocks is repressed by the N-status. The use of various metabolic uncouplers or inhibitors indicated that NO3− net uptake mediated by iHATS and LATS was an active transport system in both rootstocks. PMID:19516998

Graft union formation in tomato plants: peroxidase and catalase involvement.

PubMed

Fernandez-Garcia, Nieves; Carvajal, Micaela; Olmos, Enrique

2004-01-01

The use of grafted plants in vegetable crop production is now being expanded greatly. However, few data are available on the formation of graft unions in vegetables. In this work, the structural development of the graft union formation in tomato plants is studied, together with the possible relationship with activities of peroxidases and catalases. Tomato (Lycopersicon esculentum Mill.) seedlings of cultivar Fanny were grafted on the rootstock of cultivar AR-9704 using the 'tongue approach grafting' method, and were grown in a crop chamber. A study of the structural development of the graft union and the involvement of peroxidases and catalases in the process of graft formation was carried out during the first stages of the graft union (4, 8 and 15 d after grafting). Observation of the structure of the graft union showed formation of xylem and phloem vessels through the graft union 8 d after grafting. In addition, root hydraulic conductance, L0, indicate that the graft union is fully functional 8 d after grafting, which coincided with an increase of peroxidase and catalase activities. These results suggest that increased peroxidase and catalase activities might be implicated in graft development in tomato plants.

Rootstock and vineyard floor management influence on 'Cabernet Sauvignon' grape yeast assimilable nitrogen (YAN).

PubMed

Lee, Jungmin; Steenwerth, Kerri L

2011-08-01

This is a study on the influence that two rootstocks (110R, high vigour; 420A, low vigour) and three vineyard floor management regimes (tilled resident vegetation - usual practise in California, and barley cover crops that were either mowed or tilled) had upon grape nitrogen-containing compounds (mainly ammonia and free amino acids recalculated as YAN), sugars, and organic acids in 'Cabernet Sauvignon' clone 8. A significant difference was observed for some of the free amino acids between rootstocks. In both sample preparation methods (juiced or chemically extracted), 110R rootstock grapes were significantly higher in SER, GLN, THR, ARG, VAL, ILE, LEU, and YAN than were 420A rootstock grapes. Differences in individual free amino acid profiles and concentrations were observed between the two sample preparations, which indicate that care should be taken when comparing values from dissimilar methods. No significant differences among vineyard floor treatments were detected, which suggests that mowing offers vineyard managers a sustainable practise, alternative to tilling, without negatively affecting grape nitrogen compounds, sugars, or organic acids. Published by Elsevier Ltd.

Effects of rootstock on the composition of bergamot (Citrus bergamia Risso et Poiteau) essential oil.

PubMed

Verzera, Antonella; Trozzi, Alessandra; Gazea, Florea; Cicciarello, Giuseppe; Cotroneo, Antonella

2003-01-01

This paper reports the composition of bergamot oils obtained from plants grafted on the following rootstocks: sour orange, Carrizo citrange, trifoliate orange, Alemow, Volkamerian lemon, and Troyer citrange. The aim of this study is to evaluate the possibility of using rootstocks other than sour orange, checking their effect on the composition of the essential oil. Results are reported for analysis of 203 bergamot oils during the years 1997-1998, 1998-1999, and 1999-2000. The oils were analyzed by HRGC and HRGC/MS; 78 components were identified, and the results were in agreement with those reported in the literature for the Calabrian bergamot oils obtained from industry. Because of the quality of their essential oils, Alemow and Volkamerian lemon can be considered as substitutes for sour orange rootstocks.

Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: physiological responses.

PubMed

Penella, Consuelo; Nebauer, Sergio G; Bautista, Alberto San; López-Galarza, Salvador; Calatayud, Ángeles

2014-06-15

Recent studies have shown that tolerance to abiotic stress, including water stress, is improved by grafting. In a previous work, we took advantage of the natural variability of Capsicum spp. and selected accessions tolerant and sensitive to water stress as rootstocks. The behavior of commercial cultivar 'Verset' seedlings grafted onto the selected rootstocks at two levels of water stress provoked by adding 3.5 and 7% PEG (polyethylene glycol) was examined over 14 days. The objective was to identify the physiological traits responsible for the tolerance provided by the rootstock in order to determine if the tolerance is based on the maintenance of the water relations under water stress or through the activation of protective mechanisms. To achieve this goal, various physiological parameters were measured, including: water relations; proline accumulation; gas exchange; chlorophyll fluorescence; nitrate reductase activity; and antioxidant capacity. Our results indicate that the effect of water stress on the measured parameters depends on the duration and intensity of the stress level, as well as the rootstock used. Under control conditions (0% PEG) all plant combinations showed similar values for all measured parameters. In general terms, PEG provoked a strong decrease in the gas exchange parameters in the cultivar grafted onto the sensitive accessions, as also observed in the ungrafted plants. This effect was related to lower relative water content in the plants, provoked by an inefficient osmotic adjustment that was dependent on reduced proline accumulation. At the end of the experiment, chronic photoinhibition was observed in these plants. However, the plants grafted onto the tolerant rootstocks, despite the reduction in photosynthetic rate, maintained the protective capacity of the photosynthetic machinery mediated by osmotic adjustment (based on higher proline content). In addition, water stress limited uptake and further NO3(-) transfer to the leaves. Increased nitrate reductase activity in the roots was observed, mainly in plants grafted onto the sensitive rootstocks, as well as the ungrafted plants, and this was associated with the lessened flux to the leaves. This study suggests that PEG-induced water stress can be partially alleviated by using tolerant accessions as rootstocks. Copyright © 2014 Elsevier GmbH. All rights reserved.

Fruit quality of seedless watermelon grafted onto squash rootstocks under different production systems.

PubMed

Liu, Qianru; Zhao, Xin; Brecht, Jeffrey K; Sims, Charles A; Sanchez, Tatiana; Dufault, Nicholas S

2017-11-01

The market demand for seedless watermelon has been continuously increasing because of consumer preference. Grafting is a useful tool to manage soilborne diseases in watermelon production, but the use of squash rootstocks may negatively affect watermelon fruit quality. Currently, most research has focused on seeded cultivars, while grafting effects on seedless watermelons remain largely unknown. This multi-season study was conducted to assess the effects of squash rootstocks, including both Cucurbita maxima × C. moschata and C. moschata cultivars, with intact or excised and regenerated roots, on fruit quality of seedless watermelon 'Melody' using both instrumental and sensory measurements under different production scenarios. The grafted watermelon plants were also challenged by field inoculation with Fusarium oxysporum f.sp. niveum. A combination of instrumental measurements and consumer sensory analyses suggested that fruit quality of the seedless watermelon 'Melody' was not impacted by the use of the squash rootstocks used in this study, which included soluble solids content, titratable acidity, pH and most fruit sensory properties. Watermelon flesh firmness was increased by grafting but the grafting effect on lycopene content was inconclusive. Root excision and regeneration did not influence the grafting effect, whereas the grafting effect on flesh firmness varied among the rootstocks under Fusarium inoculation. Overall, grafting with squash rootstocks did not reduce fruit quality attributes of 'Melody' but improved texture. Our results support incorporating grafting into integrated management programs for seedless watermelon production. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Graft union formation in grapevine induces transcriptional changes related to cell wall modification, wounding, hormone signalling, and secondary metabolism

PubMed Central

Cookson, Sarah Jane; Clemente Moreno, Maria José; Hevin, Cyril; Nyamba Mendome, Larissa Zita; Delrot, Serge; Trossat-Magnin, Claudine; Ollat, Nathalie

2013-01-01

Grafting is particularly important to the cultivation of perennial crops such as grapevine (Vitis vinifera) because rootstocks can provide resistance to soil-borne pests and diseases as well as improve tolerance to some abiotic stresses. Successful grafting is a complex biochemical and structural process beginning with the adhesion of the two grafted partners, followed by callus formation and the establishment of a functional vascular system. At the molecular level, the sequence of events underlying graft union formation remains largely uncharacterized. The present study investigates the transcriptome of grapevine rootstock and graft interface tissues sampled 3 d and 28 d after grafting of over-wintering stems in the spring. Many genes were differentially expressed over time, from 3 d to 28 d after grafting, which could be related to the activation of stem growth and metabolic activity in the spring. This hypothesis is supported by the up-regulation of many genes associated with cell wall synthesis, and phloem and xylem development. Generally, there was an up-regulation of gene expression in the graft interface tissue compared with the rootstock, particularly genes involved in cell wall synthesis, secondary metabolism, and signalling. Although there was overlap between the genes differentially expressed over time (from 3 d to 28 d after grafting) with the gene differentially expressed between the rootstock and the graft interface, numerous graft interface-specific genes were identified. PMID:23698628

Improving agronomic water use efficiency in tomato by rootstock-mediated hormonal regulation of leaf biomass.

PubMed

Cantero-Navarro, Elena; Romero-Aranda, Remedios; Fernández-Muñoz, Rafael; Martínez-Andújar, Cristina; Pérez-Alfocea, Francisco; Albacete, Alfonso

2016-10-01

Water availability is the most important factor limiting food production, thus developing new scientific strategies to allow crops to more efficiently use water could be crucial in a world with a growing population. Tomato is a highly water consuming crop and improving its water use efficiency (WUE) implies positive economic and environmental effects. This work aimed to study and exploit root-derived hormonal traits to improve WUE in tomato by grafting on selected rootstocks. Firstly, root-related hormonal parameters associated to WUE were identified in a population of recombinant inbred lines (RILs) derived from the wild tomato species Solanum pimpinellifolium. A principal component analysis (PCA) revealed that some hormonal traits were associated with productivity (plant biomass and photosynthesis) and WUE in the RIL population. Leaf ABA concentration was associated to the first component (PC1) of the PCA, which explained a 60% of the variance in WUE, while the ethylene precursor ACC and the ratio ACC/ABA were also associated to PC1 but in the opposite direction. Secondly, we selected RILs according to their extreme biomass (high, B, low, b) and water use (high, W, low, w), and studied the differential effect of shoot and root on WUE by reciprocal grafting. In absence of any imposed stress, there were no rootstock effects on vegetative shoot growth and water relations. Finally, we exploited the previously identified root-related hormonal traits by grafting a commercial tomato variety onto the selected RILs to improve WUE. Interestingly, rootstocks that induced low biomass and water use, 'bw', improved fruit yield and WUE (defined as fruit yield/water use) by up to 40% compared to self-grafted plants. Although other hormonal factors appear implicated in this response, xylem ACC concentration seems an important root-derived trait that inhibits leaf growth but does not limit fruit yield. Thus tomato WUE can be improved exploiting rootstock-derived hormonal signals which control leaf growth. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Bacteria as growth-promoting agents for citrus rootstocks.

PubMed

Giassi, Valdionei; Kiritani, Camila; Kupper, Katia Cristina

2016-09-01

The microbial community plays an essential role in maintaining the ecological balance of soils. Interactions between microorganisms and plants have a major influence on the nutrition and health of the latter, and growth-promoting rhizobacteria can be used to improve plant development through a wide range of mechanisms. Therefore, the objective of the present study was to evaluate bacteria as growth-promoting agents for citrus rootstocks. A total of 30 bacterial isolates (11 of Bacillus spp., 11 actinobacteria, and 8 lactic acid bacteria) were evaluated in vitro for indoleacetic acid production, phosphate solubilization, and nitrogen (N) fixation. In vivo testing consisted of growth promotion trials of the bacterial isolates that yielded the best results on in vitro tests with three rootstocks: Swingle citrumelo [Citrus×paradisi Macfad cv. Duncan×Poncirus trifoliata (L.) Raf.], Sunki mandarin (Citrus sunki Hort. ex Tan), and rangpur (Citrus×limonia Osbeck). The parameters of interest were height, number of leaves, stem diameter, shoot and root dry mass, and total dry mass at 150days after germination. The results showed that most bacterial isolates were capable of IAA production. Only one lactic acid bacterium isolate (BL06) solubilized phosphate, with a high solubilization index (PSI>3). In the actinobacteria group, isolates ACT01 (PSI=2.09) and ACT07 (PSI=2.01) exhibited moderate phosphate-solubilizing properties. Of the Bacillus spp. isolates, only CPMO6 and BM17 solubilized phosphate. The bacterial isolates that most fixated nitrogen were BM17, ACT11, and BL24. In the present study, some bacteria were able to promote growth of citrus rootstocks; however, this response was dependent on plant genotype and isolate. Bacillus spp. BM16 and CPMO4 were able to promote growth of Swingle citrumelo. In Sunki mandarin plants, the best treatment results were obtained with BM17 (Bacillus sp.) and ACT11 (actinobacteria). For Rangpur lime rootstock, only BM05 (Bacillus sp.) was able to promote increase in two parameters assessed, height and number of leaves. When the bacterial isolates were used in mixture there was not promoted growth of plants on rootstocks. This fact may be associated with the different mechanisms of action of each bacteria involved or with the presence of competition among the microorganisms of the mixture. Copyright © 2016 Elsevier GmbH. All rights reserved.

Prunus rootstocks

USDA-ARS?s Scientific Manuscript database

New clonal Prunus hybrid rootstocks for apricot and plums offer improved adaptation to site related problems including soil borne diseases, waterlogging, calcareous soils and various species of nematodes. Additionally, they offer varying degrees of vigor control compared to standard seedling and clo...

Quantitative Aspects of the Development of Meloidogyne arenaria Larvae in Grapevine Varieties and Rootstocks.

PubMed

Ferris, H; Hunt, W A

1979-04-01

The development and productivity of parasitic stages of Meloidogyne arenaria were quantitatively defined in 14 varieties or rootstocks of grapevine. Mean development to maturity was related linearly to the number of degree-hours above 10 C temperature experienced from the time of penetration in all cultivars in which nematode adulthood was achieved. Averaged across varieties, 13,142 heat units were required for development of the mean individual to maturity. The standard deviation of the developing individuals about the mean, expressed as a proportion with 1 representing adulthood, did not differ with time or among varieties after 7,000 degree-hours had elapsed. Earliest egg production was observed after 7,662 degree-hours, averaged across varieties, considerably before mean development to maturity. Varieties were also ranked relative to the number of larvae establishing infection sites, and the rate of egg production per adult female. Varieties could he grouped according to their levels of horizontal resistance.

Effect of the rootstock and interstock grafted in lemon tree (Citrus limon (L.) Burm.) on the flavonoid content of lemon juice.

PubMed

Gil-Izquierdo, Angel; Riquelme, María T; Porras, Ignacio; Ferreres, Federico

2004-01-28

The grafting of the rootstock with the lemon tree is an agronomical technique used to improve production and/or quality of the fruit. The interstock has been used with different fruit trees to modulate the tree size, fruit production and quality, and the aging of the tree. The lemon trees grafted with interstocks increase their longevity, lemon production and quality; interstocks are also used to decrease the thickness of the trunk at the grafting point. This enlarging of the trunk provokes a decrease of the sap flow. In our study, "Verna" lemon trees were grafted with interstock between the rootstock and the lemon tree to follow the flavonoid content of the lemon juice. The lemon juice was obtained from the lemons collected of the grafted lemon trees. Two types of rootstocks were used: Citrus aurantium L. and Citrus macrophylla L. Seven interstocks from five cultivars of orange tree, one cultivar of lime tree, and one cultivar of tangerine tree were used. "Verna" lemon trees were also grafted directly to the rootstock. The rootstock was more important agronomic factor than the interstock on the total flavonoid content of lemon juice. The interstock grafting had only a small influence on the flavonoid content of the lemon juice, and it modulated the individual flavonoid content. Citrus aurantium L. rootstock and "Berna" and "Washington Navel" interstocks were the most appropriate to graft in the lemon tree. This interstock grafting technique does not increase the flavonoid content of the lemon juice. Regarding the individual flavonoids, the 6,8-di-C-glucosyl diosmetin was the most affected flavonoid by the type of rootstock used. The interstock used is able to alter the individual quantitative flavonoid order of eriocitrin, diosmin, and hesperidin. In addition, the HPLC-ESI/MS(n) analyses provided the identification of two new flavonoids in the lemon juice: Quercetin 3-O-rutinoside-7-O-glucoside and chrysoeriol 6,8-di-C-glucoside (stellarin-2). The occurrence of apigenin 6,8-di-C-glucoside (vicenin-2), eriodictyol 7-O-rutinoside, 6,8-di-C-glucosyl diosmetin, hesperetin 7-O-rutinoside, homoeriodictyol 7-O-rutinoside and diosmetin 7-O-rutinoside was also confirmed in lemon juice by this technique.

Parentage Analysis of Freedom Rootstock

USDA-ARS?s Scientific Manuscript database

The rootstock Freedom has been widely deployed for nematode resistance in California vineyards. As the offspring of two open-pollinated parents, its risk of V. vinifera-derived phylloxera susceptibility is unknown. In order to determine the progenitors of Freedom, genetic profiles of candidate paren...

Host Suitability of Eight Prunus spp. and One Pyrus communis Rootstocks to Pratylenchus vulnus, P. neglectus, and P. thornei

PubMed Central

Pinochet, J.; Verdejo-Lucas, S.; Marull, J.

1991-01-01

The effects of Pratylenchus vulnus on rootstocks of eight commonly used Prunus spp. and one Pyrus communis were evaluated under greenhouse conditions during a 15-month period. In a first experiment, two almonds (Moncayo and Garrigues), one peach (GF-305), and two peach-almond hybrids (GF-677 and Adafuel) inoculated with 2,000 nematodes per plant proved to be good hosts of P. vulnus. Highest (P < 0.05) numbers of nematodes per gram of fresh root weight were recovered from Adafuel and GF-677. Root weights were higher in uninoculated compared to inoculated plants of all rootstocks, whereas top weights of uninoculated Garrigues, GF-305, and GF-677 differed (P < 0.05) from those of inoculated plants. In a second experiment, three plum (Marianna 2624, Myrobalan 605, and San Julian 655-2) and one pear (OHF-333) rootstocks were also found to be good hosts of P. vulnus, although significantly fewer nematodes were recovered from Myrohalan 605 roots than from the other three materials. Inoculated OHF-333 and San Julian 655-2 differed (P < 0.05) in root weights over uninoculated plants. Only inoculated San Julian 655-2 showed differences in top weights over uninoculated treatments. Rootstocks were poor or non-hosts for P. neglectus and P. thornei. PMID:19283165

In vitro propagation of persimmon (Diospyros kaki Thunb.).

PubMed

Giordani, Edgardo; Naval, Mar; Benelli, Carla

2013-01-01

Persimmon (Diospyros kaki Thunb.) is a temperate fruit tree species diffused in all continents. The traditional propagation method adopted by the nursery industry is based on budding/grafting scion cultivars on seedlings from D. kaki, Diospyros lotus, and Diospyros virginiana, the most important species used as rootstock, reproduced by seeds since they are not easy to root. Furthermore, most of nonastringent cultivars of persimmon are not compatible with D. lotus, a rootstock largely utilized because of its hardiness and frost resistance. The main in vitro tissue culture techniques, developed for persimmon, deal with direct regeneration (from dormant buds and root tips), and indirect regeneration through callus from dormant buds, apexes, and leaves. The bottlenecks of micropropagation are (1) the recalcitrance of many cultivars to in vitro establishment, (2) the low multiplication ratio of D. kaki compared to other fruit tree species, (3) the very low rooting ability of ex novo microcuttings both from direct and indirect regeneration, (4) the high sensitivity to transplant from in vitro to in vivo conditions. The development of reliable in vitro regeneration procedures is likely to play a key role for production of both clonal rootstocks and self-rooted cultivars. The general protocol for micropropagation of persimmon reported here is based on the establishment of winter dormant buds in vitro, shoot development, multiplication and elongation, and shoot rooting, using cytokinins (BA or zeatin) in a MS media along with an auxinic pretreatment for rooting induction.

GRAFTING FOR CONTROL OF MELOIDOGYNE INCOGNITA ON BELL PEPPER, TOMATO, AND MELONS

USDA-ARS?s Scientific Manuscript database

Greenhouse, microplot, and field trials were conducted over three-years to evaluate rootstocks for root-knot nematode (Meloidogyne incognita) resistance. Rootstocks were evaluated for bell pepper (Capsicum annuum), tomato (Solanum esculentum), cantaloupe (Cucumis melo), and watermelon (Citrullus lan...

Crop-Specific Grafting Methods, Rootstocks and Scheduling-Tomato

USDA-ARS?s Scientific Manuscript database

Grafting has gained popularity as a method to manage plant diseases previously controlled by soil fumigation with methyl bromide. Some of the most significant soilborne pest problems for which resistant rootstocks may be beneficial include root-knot nematodes, Verticillium wilt, and southern blight....

Lesser peachtree borer (Lepidoptera: Sesiidae) oviposition on Prunus germplasm

USDA-ARS?s Scientific Manuscript database

Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sesiidae) was used as an oviposition surrogate for the congeneric S. exitiosa (Say) to examine possible preference for Prunus germplasm. We assayed limbs of a peach cultivar (Prunus persica), peach rootstocks, plum-peach hybrid rootstocks, the...

Transcriptome Profiling to Understand the Effect of Citrus Rootstocks on the Growth of ‘Shatangju’ Mandarin

PubMed Central

Liu, Meng-Meng; Yao, Qing; Chen, Jie-Zhong

2017-01-01

To obtain insight into potential mechanisms underlying the influence of rootstock on scion growth, we performed a comparative analysis of ‘Shatangju’ mandarin grafted onto 5 rootstocks: Fragrant orange (Citrus junons Sieb. ex. Tanaka), Red tangerine (Citrus reticulata Blanco), ‘Shatangju’ mandarin (Citrus reticulata Blanco), Rough lemon (Citrus jambhiri Lush) and Canton lemon (Citrus limonia Osbeck). The tree size of ‘Shatangju’ mandarin grafted onto Canton lemon and Rough lemon were the largest, followed by self-rooted rootstock trees, and the lowest tree sizes correspond to ones grafted on Red tangerine and Fragrant orange rootstocks. The levels of indoleacetic acid (IAA) and gibberellin (GA) were significantly and positively related to growth vigor. The differences of gene expression in leaves of trees grafted onto Red tangerine, Canton lemon and ‘Shatangju’ mandarin were analyzed by RNA-Seq. Results showed that more differentially expressed genes involved in oxidoreductase function, hormonal signal transduction and the glycolytic pathway were enriched in ‘Red tangerine vs Canton lemon’. qRT-PCR analysis showed that expression levels of ARF1, ARF8, GH3 and IAA4 were negatively correlated with the growth vigor and IAA content. The metabolism of GA was influenced by the differential expression of KO1 and GA2OX1 in grafted trees. In addition, most of antioxidant enzyme genes were up-regulated in leaves of trees grafted onto Red tangerine, resulting in a higher peroxidase activity. We concluded that different rootstocks significantly affected the expression of genes involved in auxin signal transduction pathway and GA biosynthesis pathway in the grafted plants, and then regulated the hormone levels and their signal pathways. PMID:28081213

Transcriptome Profiling to Understand the Effect of Citrus Rootstocks on the Growth of 'Shatangju' Mandarin.

PubMed

Liu, Xiang-Yu; Li, Juan; Liu, Meng-Meng; Yao, Qing; Chen, Jie-Zhong

2017-01-01

To obtain insight into potential mechanisms underlying the influence of rootstock on scion growth, we performed a comparative analysis of 'Shatangju' mandarin grafted onto 5 rootstocks: Fragrant orange (Citrus junons Sieb. ex. Tanaka), Red tangerine (Citrus reticulata Blanco), 'Shatangju' mandarin (Citrus reticulata Blanco), Rough lemon (Citrus jambhiri Lush) and Canton lemon (Citrus limonia Osbeck). The tree size of 'Shatangju' mandarin grafted onto Canton lemon and Rough lemon were the largest, followed by self-rooted rootstock trees, and the lowest tree sizes correspond to ones grafted on Red tangerine and Fragrant orange rootstocks. The levels of indoleacetic acid (IAA) and gibberellin (GA) were significantly and positively related to growth vigor. The differences of gene expression in leaves of trees grafted onto Red tangerine, Canton lemon and 'Shatangju' mandarin were analyzed by RNA-Seq. Results showed that more differentially expressed genes involved in oxidoreductase function, hormonal signal transduction and the glycolytic pathway were enriched in 'Red tangerine vs Canton lemon'. qRT-PCR analysis showed that expression levels of ARF1, ARF8, GH3 and IAA4 were negatively correlated with the growth vigor and IAA content. The metabolism of GA was influenced by the differential expression of KO1 and GA2OX1 in grafted trees. In addition, most of antioxidant enzyme genes were up-regulated in leaves of trees grafted onto Red tangerine, resulting in a higher peroxidase activity. We concluded that different rootstocks significantly affected the expression of genes involved in auxin signal transduction pathway and GA biosynthesis pathway in the grafted plants, and then regulated the hormone levels and their signal pathways.

Factors affecting induction and development of in vitro rooting in apple rootstocks.

PubMed

Sharma, T; Modgil, M; Thakur, M

2007-09-01

Shoots of apple rootstocks raised in vitro were transferred to various rooting media to study the effect of different factors on root initiation and development. Various concentrations of indole-3-butyric acid (IBA) initiated rooting but maximum rooting percentage was found with 2.0 and 2.5 mg l(-1) of IBA in M7 and with 1.0 mg l(-1) of IBA in MM106. The drawback was that the roots were thick, short and with profuse callus. The presence of activated charcoal (AC) in the rooting medium improved the rooting quality but reduced the rooting percentage in both the rootstocks. In high auxin dip of 70, 80 and 90 mg l(-1) IBA for 2, 2 and 1 hr showed 75-85 per cent rooting in M7, but lacked reproducibility of the results. Whereas in MM106, 66 - 70 % rooting was achieved with 70 mg l(-1) of IBA dip for 3 h. Root induction in shoots in IBA containing liquid medium (LM) in dark for few days and root elongation in IBA--free medium in light proved most effective. On the other hand, continuous light treatment showed reduced rooting. Reduction of MS salts and sucrose in root elongation medium showed decreased rooting. Plantlets from two--stage rooting procedure showed more rapid growth and satisfactory survival during hardening of plants and on transfer to field.

Evaluating and improving rootstocks for apple cultivation

USDA-ARS?s Scientific Manuscript database

The foundations of a productive and healthy orchard are the rootstocks that provide anchorage, water and nutrients essential to the above ground portions of the trees. The utilization of composite trees has increased the efficiency of breeding productive apple trees by dividing the selection of sci...

NMR Spectroscopy Identifies Metabolites Translocated from Powdery Mildew Resistant Rootstocks to Susceptible Watermelon Scions.

PubMed

Mahmud, Iqbal; Kousik, Chandrasekar; Hassell, Richard; Chowdhury, Kamal; Boroujerdi, Arezue F

2015-09-16

Powdery mildew (PM) disease causes significant loss in watermelon. Due to the unavailability of a commercial watermelon variety that is resistant to PM, grafting susceptible cultivars on wild resistant rootstocks is being explored as a short-term management strategy to combat this disease. Nuclear magnetic resonance-based metabolic profiles of susceptible and resistant rootstocks of watermelon and their corresponding susceptible scions (Mickey Lee) were compared to screen for potential metabolites related to PM resistance using multivariate principal component analysis. Significant score plot differences between the susceptible and resistant groups were revealed through Mahalanobis distance analysis. Significantly different spectral buckets and their corresponding metabolites (including choline, fumarate, 5-hydroxyindole-3-acetate, and melatonin) have been identified quantitatively using multivariate loading plots and verified by volcano plot analyses. The data suggest that these metabolites were translocated from the powdery mildew resistant rootstocks to their corresponding powdery mildew susceptible scions and can be related to PM disease resistance.

Transcriptional regulation of lycopene metabolism mediated by rootstock during the ripening of grafted watermelons.

PubMed

Kong, Qiusheng; Yuan, Jingxian; Gao, Lingyun; Liu, Peng; Cao, Lei; Huang, Yuan; Zhao, Liqiang; Lv, Huifang; Bie, Zhilong

2017-01-01

Rootstocks have comprehensive effects on lycopene accumulation in grafted watermelon fruits. However, little is known about lycopene metabolic regulation in grafted watermelon. To address this problem, parallel changes in lycopene contents and the expression of its metabolic genes were analyzed during the fruit ripening of nongrafted watermelon and watermelon grafted onto bottle gourd, pumpkin, and wild watermelon. Results showed that rootstocks mediated the transcriptional regulations of lycopene accumulation in different ways. Bottle gourd and wild watermelon promoted lycopene accumulation in grafted watermelon fruits by upregulating the biosynthetic genes phytoene synthase (PSY) and ζ-carotene desaturase (ZDS), and downregulating the catabolic genes β-carotene hydroxylase (CHYB), zeaxanthin epoxidase (ZEP), 9-cis-epoxycarotenoid dioxygenase (NCED), and carotenoid cleavage dioxygenase (CCD). However, pumpkin did not affect lycopene accumulation by upregulating both biosynthetic and catabolic genes. The rootstock-dependent characteristic of lycopene accumulation in grafted watermelon fruits provided an alternative model for investigating lycopene metabolic regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of the genetic diversity of the Tunisian citrus rootstock germplasm

PubMed Central

2012-01-01

Background Citrus represents a substantial income for farmers in the Mediterranean Basin. However, the Mediterranean citrus industry faces increasing biotic and abiotic constraints. Therefore the breeding and selection of new rootstocks are now of the utmost importance. In Tunisia, in addition to sour orange, the most widespread traditional rootstock of the Mediterranean area, other citrus rootstocks and well adapted to local environmental conditions, are traditionally used and should be important genetic resources for breeding. To characterize the diversity of Tunisian citrus rootstocks, two hundred and one local accessions belonging to four facultative apomictic species (C. aurantium, sour orange; C. sinensis, orange; C. limon, lemon; and C. aurantifolia, lime) were collected and genotyped using 20 nuclear SSR markers and four indel mitochondrial markers. Multi-locus genotypes (MLGs) were compared to references from French and Spanish collections. Results The differentiation of the four varietal groups was well-marked. The groups displayed a relatively high allelic diversity, primarily due to very high heterozygosity. Sixteen distinct MLGs were identified. Ten of these were noted in sour oranges. However, the majority of the analysed sour orange accessions corresponded with only two MLGs, differentiated by a single allele, likely due to a mutation. The most frequent MLG is shared with the reference sour oranges. No polymorphism was found within the sweet orange group. Two MLGs, differentiated by a single locus, were noted in lemon. The predominant MLG was shared with the reference lemons. Limes were represented by three genotypes. Two corresponded to the 'Mexican lime' and 'limonette de Marrakech' references. The MLG of 'Chiiri' lime was unique. Conclusions The Tunisian citrus rootstock genetic diversity is predominantly due to high heterozygosity and differentiation between the four varietal groups. The phenotypic diversity within the varietal groups has resulted from multiple introductions, somatic mutations and rare sexual recombination events. Finally, this diversity study enabled the identification of a core sample of accessions for further physiological and agronomical evaluations. These core accessions will be integrated into citrus rootstock breeding programs for the Mediterranean Basin. PMID:22429788

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.

Rootstocks: diversity, domestication and impacts on shoot phenotypes

USDA-ARS?s Scientific Manuscript database

Grafting is an ancient agricultural practice that joins the root system (rootstock) of one plant to the shoot system (scion) of another individual. It is most commonly employed in woody perennial crops such as Apples, Grapes, and Citrus species to shorten scion juvenile stage length, facilitate clo...

Elevation, rootstock, and soil depth affect the nutritional quality of mandarin oranges

USDA-ARS?s Scientific Manuscript database

The effects of elevation, rootstock, and soil depth on the nutritional quality of mandarin oranges from 11 groves in California were investigated by nuclear magnetic resonance (NMR) spectroscopy by quantifying 29 compounds and applying multivariate statistical data analysis. A comparison of the juic...

Phenotypic screening of pecan seedling rootstocks in search of nematode resistance

USDA-ARS?s Scientific Manuscript database

Open-pollinated rootstocks of pecan, Carya aquatica, and their hybrid were screened for nematode resistance in outdoor above-ground box plots. Seedstocks were selected to represent the broad geographic range of species diversity. Seedlings were inoculated with eggs of Meloidogyne partytila, the pr...

Rootstock control of scion transpiration and its acclimation to water deficit are controlled by different genes.

PubMed

Marguerit, Elisa; Brendel, Oliver; Lebon, Eric; Van Leeuwen, Cornelis; Ollat, Nathalie

2012-04-01

The stomatal control of transpiration is one of the major strategies by which plants cope with water stress. Here, we investigated the genetic architecture of the rootstock control of scion transpiration-related traits over a period of 3 yr. The rootstocks studied were full sibs from a controlled interspecific cross (Vitis vinifera cv. Cabernet Sauvignon × Vitis riparia cv. Gloire de Montpellier), onto which we grafted a single scion genotype. After 10 d without stress, the water supply was progressively limited over a period of 10 d, and a stable water deficit was then applied for 15 d. Transpiration rate was estimated daily and a mathematical curve was fitted to its response to water deficit intensity. We also determined δ(13) C values in leaves, transpiration efficiency and water extraction capacity. These traits were then analysed in a multienvironment (year and water status) quantitative trait locus (QTL) analysis. Quantitative trait loci, independent of year and water status, were detected for each trait. One genomic region was specifically implicated in the acclimation of scion transpiration induced by the rootstock. The QTLs identified colocalized with genes involved in water deficit responses, such as those relating to ABA and hydraulic regulation. Scion transpiration rate and its acclimation to water deficit are thus controlled genetically by the rootstock, through different genetic architectures. © 2012 INRA. New Phytologist © 2012 New Phytologist Trust.

'Jones hybrid' hickory: a case study in Carya curation.

PubMed

Grauke, L J; Mendoza-Herrera, M Azucena; Stelly, David M; Klein, Patricia E

2016-01-01

'Jones Hybrid' hickory is an accession in the National Collection of Genetic Resources for Pecans and Hickories for which information about origin, identity and characteristics is very incomplete. Phenotypic and genetic profiles, when examined in the context of historic literature, provide evidence that the accession in question is 'Siers' a cultivar of Carya  ×  laneyi (an interspecific hybrid between C. ovata and C. cordiformis ). The accession has traits that make it interesting in the pecan breeding program, with potential for both rootstock and scion development. The tall, slender tree form of 'Jones Hybrid' is a trait that could be valuable in commercial pecan cultivars, allowing increased tree densities and reducing the need for expensive hedging operations. Tree size reduction is a goal to be pursued in scion selection and rootstock development, with each goal requiring assessment of reproductive potential of the accession.

Effects of rootstock on Xylella fastidiosa infection and grapevine sap phenolics

USDA-ARS?s Scientific Manuscript database

Pierce’s disease, caused by the bacterium Xylella fastidiosa, poses a threat to grape production in the United States and warm climates elsewhere. There are numerous grapevine rootstocks available that may impart increased vigor or tolerance to soil-borne pests. However, little is known about the po...

Importance of Rootstock and Scion Tomato Mosaic Virus Resistance for Grafting Heirloom Tomatoes

USDA-ARS?s Scientific Manuscript database

During the 2011-2012 tomato production season at a Florida organic farm, heirloom tomato scions grafted onto Tomato yellow leaf curl virus (TYLCV)-resistant tomato rootstocks were observed to undergo a rapid and severe wilt, and ultimately die. The soilborne fungus, Sclerotium rolfsii, was isolated...

Screening almond rootstocks for sources of resistance to Armillaria root diesease

USDA-ARS?s Scientific Manuscript database

Prunus is one of the most susceptible horticultural crops to Armillaria root disease. Resistance to the geographically isolated causal fungi Armillaria mellea and A. tabescens has been evaluated in separate field trials of almond and other Prunus rootstocks, but not in one comprehensive study. We ev...

Detection of drought tolerant genes within seedling apple rootstocks in Syria

USDA-ARS?s Scientific Manuscript database

This investigation was conducted to detect the drought tolerant genes (four genes) within seedling apple rootstocks derived from five apple genotypes, including Syrian apple cultivars. The results showed that the gene MdPepPro (a cyclophilin) was found in all studied genotypes and their progenies e...

Assessment of selected pecan and peach rootstocks for resistance to Meloidogyne partityla

USDA-ARS?s Scientific Manuscript database

Open pollinated pecan seedling rootstocks were evaluated for susceptibility to Meloidogyne partityla, M. arenaria, and M. incognita in the greenhouse. Cultivars tested included seed from ‘Apache’, ‘Caddo’, ‘Curtis’, ‘Moneymaker’, ‘Pawnee’, ‘Schley’, ‘Stuart’, and ‘Wichita’ parent trees. ‘Elliott’...

Vegetable Grafting: The Implications of a Growing Agronomic Imperative for Vegetable Fruit Quality and Nutritive Value

PubMed Central

Kyriacou, Marios C.; Rouphael, Youssef; Colla, Giuseppe; Zrenner, Rita; Schwarz, Dietmar

2017-01-01

Grafting has become an imperative for intensive vegetable production since chlorofluorocarbon-based soil fumigants were banned from use on grounds of environmental protection. Compelled by this development, research into rootstock–scion interaction has broadened the potential applications of grafting in the vegetable industry beyond aspects of soil phytopathology. Grafting has been increasingly tapped for cultivation under adverse environs posing abiotic and biotic stresses to vegetable crops, thus enabling expansion of commercial production onto otherwise under-exploited land. Vigorous rootstocks have been employed not only in the open field but also under protected cultivation where increase in productivity improves distribution of infrastructural and energy costs. Applications of grafting have expanded mainly in two families: the Cucurbitaceae and the Solanaceae, both of which comprise major vegetable crops. As the main drives behind the expansion of vegetable grafting have been the resistance to soilborne pathogens, tolerance to abiotic stresses and increase in yields, rootstock selection and breeding have accordingly conformed to the prevailing demand for improving productivity, arguably at the expense of fruit quality. It is, however, compelling to assess the qualitative implications of this growing agronomic practice for human nutrition. Problems of impaired vegetable fruit quality have not infrequently been associated with the practice of grafting. Accordingly, the aim of the current review is to reassess how the practice of grafting and the prevalence of particular types of commercial rootstocks influence vegetable fruit quality and, partly, storability. Physical, sensorial and bioactive aspects of quality are examined with respect to grafting for watermelon, melon, cucumber, tomato, eggplant, and pepper. The physiological mechanisms at play which mediate rootstock effects on scion performance are discussed in interpreting the implications of grafting for the configuration of vegetable fruit physicochemical quality and nutritive value. PMID:28553298

Differential responses of grapevine rootstocks to water stress are associated with adjustments in fine root hydraulic physiology and suberization

USDA-ARS?s Scientific Manuscript database

Water deficits are known to alter fine root structure and function, but little is known about how these responses contribute to differences in drought resistance across grapevine rootstocks. We studied how water deficit affects root anatomical and physiological characteristics in two grapevine root...

Soil pH, soil type and replant disease affect growth and nutrient absorption in apple rootstocks

USDA-ARS?s Scientific Manuscript database

Rootstocks are the foundation of a healthy and productive orchard. They are the interface between the scion and the soil, providing anchorage, water, nutrients, and disease protection that ultimately affect the productivity and sustainability of the orchard. Recent advances in the science of genet...

Selecting a sampling method to aid in vegetation management decisions in loblolly pine plantations

Treesearch

David R. Weise; Glenn R. Glover

1993-01-01

Objective methods to evaluate hardwood competition in young loblolly pine (Pinustaeda L.) plantations are not widely used in the southeastern United States. Ability of common sampling rules to accurately estimate hardwood rootstock attributes at low sampling intensities and across varying rootstock spatial distributions is unknown. Fixed area plot...

Rootstock effects on almond leaf scorch disease incidence and severity

USDA-ARS?s Scientific Manuscript database

A five-year field study was conducted to evaluate effects of duration and exclusion of Xylella fastidiosa infections on young almond tree performance and their links to tree vigor. ‘Nemaguard’, ‘Okinawa’, ‘Nonpareil’, and Y119 were used as rootstocks for almond scion ‘Sonora’. Among X.fastidiosa-inf...

Screening cucurbit rootstocks for varietal resistance to Meloidogyne incognita and Rotylenchulus reniformis

USDA-ARS?s Scientific Manuscript database

Fusarium wilt (caused by the fungus Fusarium oxysporum f.sp. niveum) has been a consistent problem in the production of cucurbit species like watermelon. One method for combating this pathogen in the field is to graft a susceptible, high yielding scion on to a Fusarium wilt resistant rootstock. A co...

Consequences of Mesocriconema xenoplax parasitism on ‘Pinot noir’ grapevines grafted on rootstocks of varying susceptibility

USDA-ARS?s Scientific Manuscript database

Pinot noir grapevines grafted to five rootstocks (Vitis vinifera) and a self-rooted control known to vary in resistance to ring nematode (Mesocriconema xenoplax) were studied over four years in field microplots to 1) evaluate durability of resistance to ring nematode under conditions allowing for hi...

Phenolic and triterpenoid composition and inhibition of α-amylase of pistachio kernels (Pistacia vera L.) as affected by rootstock and irrigation treatment.

PubMed

Noguera-Artiaga, Luis; Pérez-López, David; Burgos-Hernández, Armando; Wojdyło, Aneta; Carbonell-Barrachina, Ángel A

2018-09-30

The current water scarcity forces farmers to adopt new irrigation strategies to save water without jeopardizing the fruit yield and quality. In this study, the influence of 3 regulated deficit irrigation (RDI) treatments and 3 rootstocks on the functional quality of pistachios were studied. The functional parameters studied included, polyphenols, triterpenoids, and inhibition of α-amylase. The results showed that P. terebinthus and P. atlantica rootstocks led to pistachio kernels with higher contents of polyphenols and triterpenoids (mainly betulinic acid with 111 and 102 µg g -1 , respectively) than pistachios obtained using P. integerrima rootstock (81 µg g -1 ). On the other hand, the use of moderate RDI (T1 treatment) increased the total content of polyphenols (∼10%), quercetin-O-galloyl-hexoside (∼15%), keampferol-3-O-glucoside (∼19%), and polymeric procyanidins (∼20%), as compared to the control trees, resulting in pistachios with a better functional profile, lower economic cost and with a lesser environmental impact. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhanced salt resistance in apple plants overexpressing a Malus vacuolar Na+/H+ antiporter gene is associated with differences in stomatal behavior and photosynthesis.

PubMed

Li, Chao; Wei, Zhiwei; Liang, Dong; Zhou, Shasha; Li, Yonghong; Liu, Changhai; Ma, Fengwang

2013-09-01

High salinity is a major abiotic factor that limits crop production. The dwarfing apple rootstock M.26 is sensitive to such stress. To obtain an apple that is adaptable to saline soils, we transformed this rootstock with a vacuolar Na(+)/H(+) antiporter, MdNHX1. Differences in salt tolerance between transgenic and wild-type (WT) rootstocks were examined under field conditions. We also compared differences when 'Naganofuji No. 2' apple was grafted onto these transgenic or WT rootstocks. Plants on the transgenic rootstocks grew well during 60 d of mild stress (100 mM NaCl) while the WT exhibited chlorosis, inhibited growth and even death. Compared with the untreated control, the stomatal density was greater in both non-grafted and grafted WT plants exposed to 200 mM NaCl. In contrast, that density was significantly decreased in leaves from grafted transgenic plants. At 200 mM NaCl, net photosynthesis, stomatal conductance, intercellular CO2 concentration, and chlorophyll contents were markedly reduced in the WT, whereas the declines in those values were only minor in similarly stressed transgenic plants. Therefore, we conclude that overexpressing plants utilize a better protective mechanism for retaining higher photosynthetic capacity. Furthermore, this contrast in tolerance and adaptability to stress is linked to differences in stomatal behavior and photosynthetic rates. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Differential Response to Root-Knot Nematodes in Prunus Species and Correlative Genetic Implications

PubMed Central

Esmenjaud, D.; Minot, J. C.; Voisin, R.; Pinochet, J.; Simard, M. H.; Salesses, G.

1997-01-01

Responses of 17 Prunus rootstocks or accessions (11 from the subgenus Amygdalus and 6 from the subgenus Prunophora) were evaluated against 11 isolates of Meloidogyne spp. including one M. arenaria, four M. incognita, four M. javanica, one M. hispanica, and an unclassified population from Florida. Characterization of plant response to root-knot nematodes was based on a gall index rating. Numbers of females and juveniles plus eggs in the roots were determined for 10 of the rootstocks evaluated against one M. arenaria, one M. incognita, one M. javanica, and the Florida isolate. These 10 rootstocks plus Nemaguard and Nemared were retested by growing three different rootstock genotypes together in containers of soil infested individually with each of the above four isolates. Garfi and Garrigues almonds, GF.305 and Rutgers Red Leaf peaches, and the peach-almond GF.677 were susceptible to all isolates. Differences in resistance were detected among the other rootstocks of the subgenus Amygdalus. The peach-almond GF.557 and Summergrand peach were resistant to M. arenaria and M. incognita but susceptible to M. javanica and the Florida isolate. Nemaguard, Nemared, and its two hybrids G x N no. 15 and G x N no. 22 were resistant to all but the Florida isolate. In the subgenus Prunophora, Myrobalan plums P.1079, P.2175, P.2980, and P.2984; Marianna plum 29C; and P. insititia plum AD.101 were resistant to all isolates. Thus, two different genetic systems of RKN resistance were found in the subgenus Amygdalus: one system acting against M. arenaria and M. incognita, and another system also acting against M. javanica. Prunophora rootstocks bear a complete genetic system for resistance also acting against the Florida isolate. The hypotheses on the relationships between these systems and the corresponding putative genes of resistance are presented. PMID:19274170

Seasonal carbohydrate storage and mobilization in bearing and non-bearing pistachio (Pistacia vera) trees.

PubMed

Spann, Timothy M; Beede, Robert H; Dejong, Theodore M

2008-02-01

We analyzed annual carbohydrate storage and mobilization of bearing ("on") and non-bearing ("off") 'Kerman' pistachio (Pistacia vera L.) trees growing on three different rootstocks. On all rootstocks, carbohydrate storage in shoots and branches of "on" and "off" trees was lowest following the spring growth flush. In "off" trees, stored carbohydrates increased and remained high after the initial growth flush. In "on" trees, stem carbohydrates increased temporarily in early summer, but were mobilized in mid-season during kernel fill, and then increased again after nut harvest. During the dormant season, the only substantial differences in carbohydrate storage between previously "on" and "off" trees were found in the roots of the weakest rootstock. The annual carbohydrate storage and mobilization pattern in canopy branches of heavily cropped pistachio trees appeared to be driven by carbohydrate demands related to nut development and untempered by tree vigor. Mobilization of carbohydrates from current-season and 1- and 2-year-old stem wood of "on" trees during the primary period of kernel fill corresponded with the period of inflorescence bud abscission. Thus, the alternate bearing pattern associated with inflorescence bud abscission in 'Kerman' pistachio may be a function of mid-season mobilization of stored carbohydrates in current-season stems resulting in stimulation of inflorescence bud abscission.

Can Pierce’s disease resistance introgressed into Vitis vinifera be translocated from a resistant rootstock to a susceptible scion?

USDA-ARS?s Scientific Manuscript database

The goal of this research is to evaluate the potential of a non-transgenic, PD-resistant Vitis vinifera selection used as an experimental rootstock to confer systemic resistance to PD-susceptible V. vinifera scions. Source of PD-susceptible plant material was the wine grape variety ‘Chardonnay’, kno...

Plolyamines and other secondary metabolites of green-leaf and red-leaf almond rootstocks triggered in response to salinity

USDA-ARS?s Scientific Manuscript database

Almond trees are very sensitive to salinity, and saline water is the only alternative for irrigation in many semiarid regions. Thus, the use of salt-tolerant rootstocks may allow an economically-feasible yield under saline irrigation. In this study, we evaluated the effects of chloride salts on plan...

RKVL-318, a root-knot nematode resistant rootstock line for grafted watermelon

USDA-ARS?s Scientific Manuscript database

The Agriculture Research Service, U.S. Department of Agriculture, announces the release of ‘RKVL-318’, a novel germplasm line useful as a rootstock and as a genetic resource for enhancing resistance to root-knot nematodes (RKN) in watermelon cultivars. ‘RKVL-318’ is derived from the wild-type water...

Description of a novel mild strain of Citrus tristeza virus in California that reacts with monoclonal antibody MCA13

USDA-ARS?s Scientific Manuscript database

Quick decline caused by Citrus tristeza virus (CTV) destroyed citrus on sour orange rootstock in southern California in the 1930’s -40’s. However, use of resistant/tolerant CTV rootstocks, certified pathogen-free budwood, and quarantines have limited further economic damage from CTV. Multi-locus mar...

Factors affecting the sprouting of shortleaf pine rootstock following prescribed fire

Treesearch

Curtis J. Lilly; Rodney E. Will; Charles G. Tauer; James M. Guldin; Martin A. Spetich

2012-01-01

Shortleaf pine (Pinus echinata) is a fire dependent species that is declining across the southeastern US. Its unique basal crook is an adaptation that protects dormant buds from fire and facilitates prolific sprouting of seedling rootstocks following top-kill. Understanding what influences shortleaf pine sprouting after fire could greatly increase success of natural...

Can Pierce’s disease resistance introgressed into Vitis vinifera be translocated from a resistant rootstock to a susceptible scion?

USDA-ARS?s Scientific Manuscript database

The goal of this research is to evaluate the potential of a non-transgenic, PD resistant Vitis vinifera selection used as an experimental rootstock to confer systemic resistance to PD susceptible V. vinifera scions. Source of PD susceptible plant material will be the wine grape variety ‘Chardonnay’,...

A simulation study of hardwood rootstock populations in young loblolly pine plantations

Treesearch

David R. Weise; Glenn R. Glover

1988-01-01

A computer program to simulate spatial distribution of hardwood rootstock populations is presented. Nineteen 3 to 6 yearold loblolly pine (Pinus taeda L.) plantations in Alabama and Georgia were measured to provide information for the simulator. Spatial pattern, expressed as Pielou's nonrandomness index (PNI), ranged from 0.47 to 2.45. Scatterplots illustrated no...

Fire blight resistance in wild accessions of Malus sieversii

USDA-ARS?s Scientific Manuscript database

Fire blight (Erwinia amylovora) is a devastating bacterial disease in apple that results in severe economic losses. Epidemics are becoming more common as susceptible cultivars and rootstocks are being planted, and control is becoming more difficult as antibiotic-resistant strains develop. Resistan...

Progress report to the International Fruit Tree Association

USDA-ARS?s Scientific Manuscript database

This report provides an update on several projects that are fostered by the International Fruit Tree Association which covers some aspects of rootstock development, performance in the orchard and to address nursery industry needs. The report highlights results from graft union strength experiments,...

Can Pierce’s disease PdR1 resistance introgressed into Vitis vinifera be translocated from a resistant rootstock to a susceptible scion?

USDA-ARS?s Scientific Manuscript database

The goal of this research is to evaluate the potential of a non-transgenic, PD resistant Vitis vinifera selection used as an experimental rootstock to confer systemic resistance to PD susceptible V. vinifera scions. Source of PD susceptible plant material was the wine grape variety ‘Chardonnay’, kno...

Six-year performance of 14 Prunus rootstocks at 11 sites in the 2001 NC-140 peach trial

USDA-ARS?s Scientific Manuscript database

Fourteen Prunus rootstock cultivars and selections budded with either ‘Redtop’, ‘Redhaven’ or ‘Cresthaven’ peach [Prunus persica (L.) Batsch] were planted at 11 locations in North America in 2001 in a randomized block design with a tree spacing of 5 by 6 m and 8 replicates. This test planting was a...

Grapevine necrotic union, A newly recognized disease of unknown etiology in grapevines grafted on 110 Richter rootstock in California

USDA-ARS?s Scientific Manuscript database

In Northern California, surveys of several vineyards planted to Vitis vinifera cv. Pinot noir (PN) clones 02A, 667, 777, and UCD 04 grafted onto the rootstock V. berlandieri x V. rupestris 110 Richter (110R) revealed 2 to 45% of vines showing solid red leaf canopies and two distinct disease stages, ...

Cryopreservation of apple (Malus spp.): development, progress and future prospects

USDA-ARS?s Scientific Manuscript database

Apple (Malus sp.) is one of the most economically important temperate fruit crops. Wild Malus genetic resources and existing cultivars provide valuable genes for breeding new elite cultivars and rootstocks through traditional and biotechnological breeding programs. Over the last three decades, great...

A newly developed real-time PCR assay for detection and quantification of Fusarium oxysporum and its use in compatible and incompatible interactions with grafted melon genotypes.

PubMed

Haegi, Anita; Catalano, Valentina; Luongo, Laura; Vitale, Salvatore; Scotton, Michele; Ficcadenti, Nadia; Belisario, Alessandra

2013-08-01

A reliable and species-specific real-time quantitative polymerase chain reaction (qPCR) assay was developed for detection of the complex soilborne anamorphic fungus Fusarium oxysporum. The new primer pair, designed on the translation elongation factor 1-α gene with an amplicon of 142 bp, was highly specific to F. oxysporum without cross reactions with other Fusarium spp. The protocol was applied to grafted melon plants for the detection and quantification of F. oxysporum f. sp. melonis, a devastating pathogen of this cucurbit. Grafting technologies are widely used in melon to confer resistance against new virulent races of F. oxysporum f. sp. melonis, while maintaining the properties of valuable commercial varieties. However, the effects on the vascular pathogen colonization have not been fully investigated. Analyses were performed on 'Charentais-T' (susceptible) and 'Nad-1' (resistant) melon cultivars, both used either as rootstock and scion, and inoculated with F. oxysporum f. sp. melonis race 1 and race 1,2. Pathogen development was compared using qPCR and isolations from stem tissues. Early asymptomatic melon infections were detected with a quantification limit of 1 pg of fungal DNA. The qPCR protocol clearly showed that fungal development was highly affected by host-pathogen interaction (compatible or incompatible) and time (days postinoculation). The principal significant effect (P ≤ 0.01) on fungal development was due to the melon genotype used as rootstock, and this effect had a significant interaction with time and F. oxysporum f. sp. melonis race. In particular, the amount of race 1,2 DNA was significantly higher compared with that estimated for race 1 in the incompatible interaction at 18 days postinoculation. The two fungal races were always present in both the rootstock and scion of grafted plants in either the compatible or incompatible interaction.

Rootstock influence on iron uptake responses in Citrus leaves and their regulation under the Fe paradox effect

PubMed Central

Quiñones, Ana; Bermejo, Almudena

2017-01-01

Background and aims This work evaluates the regulation of iron uptake responses in Citrus leaves and their involvement in the Fe paradox effect. Methods Experiments were performed in field-grown ‘Navelina’ trees grafted onto two Cleopatra mandarin × Poncirus trifoliata (L.) Raf. hybrids with different Fe-chlorosis symptoms: 030146 (non-chlorotic) and 030122 (chlorotic). Results Chlorotic leaves were smaller than non-chlorotic ones for both dry weight (DW) and area basis, and exhibited marked photosynthetic state affection, but reduced catalase and peroxidase enzymatic activities. Although both samples had a similar total Fe concentration on DW, it was lower in chlorotic leaves when expressed on an area basis. A similar pattern was observed for the total Fe concentration in the apoplast and cell sap and in active Fe (Fe2+) concentration. FRO2 gene expression and ferric chelate reductase (FC-R) activity were also lower in chlorotic samples, while HA1 and IRT1 were more induced. Despite similar apoplasmic pH, K+/Ca2+ was higher in chlorotic leaves, and both citrate and malate concentrations in total tissue and apoplast fluid were lower. Conclusion (1) The rootstock influences Fe acquisition system in the leaf; (2) the increased sensitivity to Fe-deficiency as revealed by chlorosis and decreased biomass, was correlated with lower FC-R activity and lower organic acid level in leaf cells, which could cause a decreased Fe mobility and trigger other Fe-stress responses in this organ to enhance acidification and Fe uptake inside cells; and (3) the chlorosis paradox phenomenon in citrus likely occurs as a combination of a marked FC-R activity impairment in the leaf and the strong growth inhibition in this organ. PMID:28966887

Selection and propagation of highly graft-compatible Douglas-fir rootstocks—a case history.

Treesearch

Donald L. Copes

1981-01-01

Two populations of Douglas-fir trees were screened for graft compatibility. Two-stage testing procedures were used with either high- or low-intensity screening in the first step. Of 303 trees, 16 (5 percent) were found to be 90- to 100-percent graft compatible and suitable for seed orchard use as rootstocks. High-intensity screening in the first stage was more...

A comparative analysis of genetic variation in rootstocks and scions of old olive trees - a window into the history of olive cultivation practices and past genetic variation.

PubMed

Barazani, Oz; Westberg, Erik; Hanin, Nir; Dag, Arnon; Kerem, Zohar; Tugendhaft, Yizhar; Hmidat, Mohammed; Hijawi, Thameen; Kadereit, Joachim W

2014-05-28

Past clonal propagation of olive trees is intimately linked to grafting. However, evidence on grafting in ancient trees is scarce, and not much is known about the source of plant material used for rootstocks. Here, the Simple Sequence Repeat (SSR) marker technique was used to study genetic diversity of rootstocks and scions in ancient olive trees from the Levant and its implications for past cultivation of olives. Leaf samples were collected from tree canopies (scions) and shoots growing from the trunk base (suckers). A total of 310 trees were sampled in 32 groves and analyzed with 14 SSR markers. In 82.7% of the trees in which both scion and suckers could be genotyped, these were genetically different, and thus suckers were interpreted to represent the rootstock of grafted trees. Genetic diversity values were much higher among suckers than among scions, and 194 and 87 multi-locus genotypes (MLGs) were found in the two sample groups, respectively. Only five private alleles were found among scions, but 125 among suckers. A frequency analysis revealed a bimodal distribution of genetic distance among MLGs, indicating the presence of somatic mutations within clones. When assuming that MLGs differing by one mutation are identical, scion and sucker MLGs were grouped in 20 and 147 multi-locus lineages (MLLs). The majority of scions (90.0%) belonged to a single common MLL, whereas 50.5% of the suckers were single-sample MLLs. However, one MLL was specific to suckers and found in 63 (22.6%) of the samples. Our results provide strong evidence that the majority of olive trees in the study are grafted, that the large majority of scions belong to a single ancient cultivar containing somatic mutations, and that the widespread occurrence of one sucker genotype may imply rootstock selection. For the majority of grafted trees it seems likely that saplings were used as rootstocks; their genetic diversity probably is best explained as the result of a long history of sexual reproduction involving cultivated, feral and wild genotypes.

A comparative analysis of genetic variation in rootstocks and scions of old olive trees – a window into the history of olive cultivation practices and past genetic variation

PubMed Central

2014-01-01

Background Past clonal propagation of olive trees is intimately linked to grafting. However, evidence on grafting in ancient trees is scarce, and not much is known about the source of plant material used for rootstocks. Here, the Simple Sequence Repeat (SSR) marker technique was used to study genetic diversity of rootstocks and scions in ancient olive trees from the Levant and its implications for past cultivation of olives. Leaf samples were collected from tree canopies (scions) and shoots growing from the trunk base (suckers). A total of 310 trees were sampled in 32 groves and analyzed with 14 SSR markers. Results In 82.7% of the trees in which both scion and suckers could be genotyped, these were genetically different, and thus suckers were interpreted to represent the rootstock of grafted trees. Genetic diversity values were much higher among suckers than among scions, and 194 and 87 multi-locus genotypes (MLGs) were found in the two sample groups, respectively. Only five private alleles were found among scions, but 125 among suckers. A frequency analysis revealed a bimodal distribution of genetic distance among MLGs, indicating the presence of somatic mutations within clones. When assuming that MLGs differing by one mutation are identical, scion and sucker MLGs were grouped in 20 and 147 multi-locus lineages (MLLs). The majority of scions (90.0%) belonged to a single common MLL, whereas 50.5% of the suckers were single-sample MLLs. However, one MLL was specific to suckers and found in 63 (22.6%) of the samples. Conclusions Our results provide strong evidence that the majority of olive trees in the study are grafted, that the large majority of scions belong to a single ancient cultivar containing somatic mutations, and that the widespread occurrence of one sucker genotype may imply rootstock selection. For the majority of grafted trees it seems likely that saplings were used as rootstocks; their genetic diversity probably is best explained as the result of a long history of sexual reproduction involving cultivated, feral and wild genotypes. PMID:24886387

MdPIN1b encodes a putative auxin efflux carrier and has different expression patterns in BC and M9 apple rootstocks.

PubMed

Gan, Zengyu; Wang, Yi; Wu, Ting; Xu, Xuefeng; Zhang, Xinzhong; Han, Zhenhai

2018-03-01

Lower promoter activity is closely associated with lower MdPIN1b expression in the M9 interstem, which might contribute to the dwarfing effect in apple trees. Apple trees grafted onto dwarfing rootstock Malling 9 (M9) produce dwarfing tree architecture with high yield and widely applying in production. Previously, we have reported that in Malus 'Red Fuji' (RF) trees growing on M9 interstem and Baleng Crab (BC) rootstock, IAA content was relatively higher in bark tissue of M9 interstem than that in scion or rootstock. As IAA polar transportation largely depends on the PIN-FORMED (PIN) auxin efflux carrier. Herein, we identify two putative auxin efflux carrier genes in Malus genus, MdPIN1a and MdPIN1b, which were closely related to the AtPIN1. We found that MdPIN1b was expressed preferentially in BC and M9, and the expression of MdPIN1b was significantly lower in the phloem of M9 interstem than that in the scion and rootstock. The distinct expression of MdPIN1b and IAA content were concentrated in the cambium and adjacent xylem or phloem, and MdPIN1b protein was localized on cell plasma membrane in onion epidermal cells transiently expressing 35S:MdPIN1b-GFP fusion protein. Interestingly, an MdPIN1b mutant allele in the promoter region upstream of M9 exhibited decreased MdPIN1b expression compared to BC. MdPIN1b over-expressing interstem in tobacco exhibited increased polar auxin transport. It is proposed that natural allelic differences decreased promoter activity is closely associated with lower MdPIN1b expression in the M9 interstem, which might limit the basipetal transport of auxin, and in turn might contribute to the dwarfing effect. Taken together, these results reveal allelic variation underlying an important apple rootstock trait, and specifically a novel molecular genetic mechanism underlying dwarfing mechanism.

Incidence of 'Candidatus Liberibacter asiaticus'-Infected Plants Among Citrandarins as Rootstock and Scion Under Field Conditions.

PubMed

Boava, Leonardo Pires; Sagawa, Cíntia Helena Duarte; Cristofani-Yaly, Mariângela; Machado, Marcos Antonio

2015-04-01

Huanglongbing (HLB), caused by the bacterium 'Candidatus Liberibacter' spp., is currently one of the most serious diseases of citrus plants and has caused substantial economic losses. Thus far, there is no source of genetic resistance to HLB in the genus Citrus or its relatives. However, several studies have reported Poncirus trifoliata and some of its hybrids to be more tolerant to the disease. The main objective of this study was to report differences in the incidence of 'Ca. L. asiaticus' infection in citrandarin plants, hybrids from Sunki mandarin (Citrus sunki (Hayata) hort. ex Tanaka), and trifoliate orange Rubidoux (P. trifoliata (L.) Raf.)), after conducting an extensive survey under field conditions. These hybrid plants were established for approximately 7 years in an area with a high incidence of 'Ca. L. asiaticus'-infected plants. We selected two experimental areas (area A and area B), located approximately 10 m apart. Area A consists of Pera sweet orange (C. sinensis (L.) Osb.) grafted onto 56 different citrandarin rootstocks. Area B consists of citrandarin scions grafted onto Rangpur lime (C. limonia Osb.) rootstock. Bacteria in the leaves and roots were detected using real-time quantitative polymerase chain reaction. The incidence of 'Ca. L. asiaticus'-infected plants was 92% in area A and 14% in area B. Because infected plants occurred in both areas, we examined whether the P. trifoliata hybrid rootstock influenced HLB development and also determined the distribution of 'Ca. L. asiaticus' in Citrus tree tissues. Although this survey does not present evidence regarding the resistance of P. trifoliata and its hybrids in relation to bacteria or psyllids, future investigation, mainly using the most promising hybrids for response to 'Ca. L. asiaticus', will help us to understand the probable mechanism of defense or identifying compounds in P. trifoliata and its hybrids that are very important as strategy to combat HLB. Details of these results are presented and discussed in this article.

Contrasting Susceptibilities to Flavescence Dorée in Vitis vinifera, Rootstocks and Wild Vitis Species

PubMed Central

Eveillard, Sandrine; Jollard, Camille; Labroussaa, Fabien; Khalil, Dima; Perrin, Mireille; Desqué, Delphine; Salar, Pascal; Razan, Frédérique; Hévin, Cyril; Bordenave, Louis; Foissac, Xavier; Masson, Jean E.; Malembic-Maher, Sylvie

2016-01-01

Flavescence dorée (FD) is a quarantine disease of grapevine, involving interactions between the plants, leafhopper vectors, and FD phytoplasma. Characterizing the susceptibility of vine varieties could limit disease propagation. After extensive surveys in vineyards, we showed that Cabernet Sauvignon (CS) is highly susceptible, with a high proportion of symptomatic branches and phytoplasma titers, in contrast to Merlot (M). Localized insect transmissions and grafting showed that phytoplasma circulate in the whole plant in the CS cultivar, but in M they are restricted to the transmission point. Insect-mediated transmission under high confinement mimicking natural conditions confirmed these phenotypes and allowed the classification of 28 Vitis accessions into three distinct categories, according to the percentage of infected plants and their phytoplasma titers. Reduced symptoms, low phytoplasma titers, and low percentages of infected plants were found to be associated in the Vitis vinifera cultivars tested. Interestingly, the low susceptibility of M was observed for one of its parents, i.e., Magdeleine Noire des Charentes. Rootstocks and their Vitis parents, although having high percentages of infected plants and intermediate to high phytoplasma titers, shared a symptomless response. This is troubling, because rootstocks can constitute a silent reservoir of contamination in mother plants or when they grow wild nearby vineyards. Altogether, data suggest distribution of genetic traits within the Vitis genus involved in insect-mediated phytoplasma transmission, multiplication, circulation, and symptom development. PMID:27965681

Involvement of aquaporin NIP1;1 in the contrasting tolerance response to root hypoxia in Prunus rootstocks.

PubMed

Mateluna, Patricio; Salvatierra, Ariel; Solis, Simón; Nuñez, Gabriel; Pimentel, Paula

2018-05-12

Prunus species have been classified as moderately sensitive to root hypoxia, but with a certain intrageneric tolerance degree to oxygen deficiency. Previously, RNA-seq analysis described the transcriptomic reconfiguration of two Prunus rootstocks contrasting to root hypoxia, which included the shift from aerobic to anaerobic metabolism. Here, we studied the relationship between lactate accumulation and the functionality of an aquaporin differentially expressed in 'Mariana 2624', a plum-based (Prunus cerasifera x Prunus munsoniana) rootstock tolerant to root hypoxia stress, and 'Mazzard F12/1', a cherry-based (Prunus avium) rootstock sensitive to root hypoxia stress. In the root hypoxia-sensitive rootstock, higher levels of lactate and LDH1 gene expression were found in roots exposed to oxygen deprivation. Concomitantly, we detected an increase in the mRNA abundance of Prunus spp. NIP1;1, a putative lactic acid transporter. Intriguingly, the high expression of PruavNIP1;1 is not linked to a lower lactic acid content in the roots of 'Mazzard F12/1'. To study this phenomenon, we calculated the force required for the transit of a lactic acid molecule through Prunus spp. NIP1;1 channels. Comparing the calculated forces, we identified steric hindrances in PruavNIP1;1 given by the residues Phe107 and Trp88 in the NPA region and ar/R filter, respectively. The functionality of both channels was corroborated by the restoration of the lactic acid transport and the differential lactic acid sensitive-phenotypes of the yeast strain Δjen1 complemented with PruavNIP1;1 and PrucxmNIP1;1. Our findings provide new insights into the mechanisms involved in determining hypoxia tolerance between closely related species, such as plum and cherry. Copyright © 2018 Elsevier GmbH. All rights reserved.

Micropropagation of Citrus spp. by organogenesis and somatic embryogenesis.

PubMed

Chiancone, Benedetta; Germanà, Maria Antonietta

2013-01-01

Citrus spp., the largest fruit crops produced worldwide, are usually asexually propagated by cuttings or grafting onto seedling rootstocks. Most of Citrus genotypes are characterized by polyembryony due to the occurrence of adventive nucellar embryos, which lead to the production of true-to-type plants by seed germination. Tissue culture and micropropagation, in particular, are valuable alternatives to traditional propagation to obtain a high number of uniform and healthy plants in a short time and in a small space. Moreover, in vitro propagation provides a rapid system to multiply the progeny obtained by breeding programs, allows the use of monoembryonic and seedless genotypes as rootstocks, and it is very useful also for breeding and germplasm preservation.In this chapter, two protocols regarding organogenesis of a rootstock and somatic embryogenesis of a cultivar have been described.

The in planta proteome of wild type strains of the fire blight pathogen, Erwinia amylovora.

PubMed

Holtappels, M; Vrancken, K; Noben, J P; Remans, T; Schoofs, H; Deckers, T; Valcke, R

2016-04-29

Erwinia amylovora is a Gram-negative plant pathogen that causes fire blight. This disease affects most members of the Rosaceae family including apple and pear. Here, an infection model is introduced to study proteomic changes in a highly virulent E. amylovora strain upon interaction with its host as compared to a lower virulent strain. For this purpose separate shoots of apple rootstocks were wound-infected and when infection became systemic, bacterial cells were isolated and processed for analysis in a proteomics platform combining 2-D fluorescence difference gel electrophoresis and mass spectrometry. Comparing the proteome of the isolates, significant abundance changes were observed in proteins involved in sorbitol metabolism, amylovoran production as well as in protection against plant defense mechanisms. Furthermore several proteins associated with virulence were more abundant in the higher virulent strain. Changes at the proteome level showed good accordance at the transcript level, as was verified by RT-qPCR. In conclusion, this infection model may be a valuable tool to unravel the complexity of plant-pathogen interactions and to gain insight in the molecular mechanisms associated with virulence of E. amylovora, paving the way for the development of plant-protective interventions against this detrimental disease. During this research a first time investigation was performed on the proteome of E. amylovora, grown inside a susceptible host plant. This bacterium is the causal agent of fire blight, which can affect most members of the Rosaceae family including apple and pear. To do so, an artificial infection model on shoots of apple rootstocks was optimized and employed. When infection was systemic, bacterial cells were extracted from the plant tissue followed by extraction of the proteins from the bacteria. Further processing of the proteins was done by using a 2-D fluorescence difference gel electrophoresis analysis followed by mass spectrometry. By the use of two strains differing in their virulent ability, we were able to draw conclusions concerning virulence and behavior of different strains inside the host. This research provides a model to investigate plant-pathogen interactions and more importantly, we identified possible new targets for the development of novel control methods against this devastating disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Cold temperature tolerance of apple rootstock trunk and root tissues

USDA-ARS?s Scientific Manuscript database

G.11, G.30, G.41, P.2 and B.9 apple (Malus xdomestica) rootstocks have root tissue hardiness similar to M.26, but G.935 has greater hardiness than M.26 when based on shoot regrowth in ungrafted trees. The LT50 of M.26 and P.2 roots ranged from -12 to -14 degrees C. The LT50 of B.9 was -13 degrees ...

Draft Genome Sequence of Agrobacterium sp. Strain UHFBA-218, Isolated from Rhizosphere Soil of Crown Gall-Infected Cherry Rootstock Colt

PubMed Central

Dua, Ankita; Sangwan, Naseer; Kaur, Jasvinder; Saxena, Anjali; Kohli, Puneet; Gupta, A. K.

2013-01-01

We report here the draft genome sequence of the alphaproteobacterium Agrobacterium sp. strain UHFBA-218, which was isolated from rhizosphere soil of crown gall-infected cherry rootstock Colt. The draft genome of strain UHFBA-218 consists of 112 contigs (5,425,303 bp) and 5,063 coding sequences with a G+C content of 59.8%. PMID:23723402

Genetics of resistance to Meloidogyne incognita in crosses of grape rootstocks.

PubMed

Cousins, P.; Walker, A.

2002-10-01

Progeny testing was used to investigate the value of selected grape varieties as parents in breeding nematode-resistant rootstocks. Six pistillate-flowered rootstocks (Ramsey, Dog Ridge, Harmony, Freedom, 1613C, and 161-49C) and four staminate-flowered rootstocks (Riparia Gloire, 3309C, 1616C, and St. George) were used. Each male was crossed to each female. Six weeks after inoculation with 1,500 second-stage juveniles of Meloidogyne incognita race 3, roots were stained in an aqueous solution of eosin-Y (0.25 gm/l for 1 h). Seedling resistance was measured by counting the number of stained nematode egg masses visible per root system. Nematode reproduction on each cross was calculated as the average number of egg masses on ten seedlings per replicate. The females Harmony and Freedom produced the greatest level of resistance in their seedlings across all male parents. Seedlings of Dog Ridge, Ramsey, and 1613C had intermediate levels of resistance, while seedlings of 161-49C were the least resistant. The male 1616C contributed the greatest resistance to its progeny, while seedlings from crosses with the males Riparia Gloire, 3309C, and St. George had lower levels of resistance. Segregation ratios of resistant and susceptible seedlings are consistent with a single dominant allele model for root-knot nematode resistance.

Relationship between endogenous hormonal content and somatic organogenesis in callus of peach (Prunus persica L. Batsch) cultivars and Prunus persica×Prunus dulcis rootstocks.

PubMed

Pérez-Jiménez, Margarita; Cantero-Navarro, Elena; Pérez-Alfocea, Francisco; Le-Disquet, Isabel; Guivarc'h, Anne; Cos-Terrer, José

2014-05-01

The relationship between endogenous hormones content and the induction of somatic peach plant was studied. To induce multiple shoots from callus derived from the base of stem explants of the scion cultivars 'UFO-3', 'Flariba' and 'Alice Bigi', and the peach×almond rootstocks 'Garnem' and 'GF677', propagated plants were cultured on Murashige and Skoog salts augmented with 0.1mgL(-1) of indolebutyric acid, 1mgL(-1) of 6-benzylaminopurine and 3% sucrose. The highest regeneration rate was obtained with the peach×almond rootstocks. Endogenous levels of abscisic acid (ABA), indole-3-acetic acid (IAA), zeatin (Z), zeatin riboside (ZR), ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), salicylic acid (SA), and jasmonic acid (JA) were analyzed in the organogenic callus. Lower levels of several hormones, namely Z, ZR, ABA, and ACC were found in the peach×almond rootstock compared to peach cultivars, while IAA and SA presented inconclusive returns. These results suggest that the difference in somatic organogenesis capacity observed in peach and peach×almond hybrids is markedly affected by the endogenous hormonal content of the studied genotypes. Copyright © 2014 Elsevier GmbH. All rights reserved.

Tolerance to powdery mildew conferred in susceptible watermelon scion by grafting on resistant rootstocks

USDA-ARS?s Scientific Manuscript database

Cucurbit powdery mildew (PM) caused by Podosphaera xanthii, can impact seedling growth and cause serious losses in greenhouse and open field production. We have developed several watermelon and bottle gourd germplasm lines with high levels of resistance to PM. A PM susceptible cultivar Mickey Lee ...

Clonal propagation of walnut rootstock genotypes for genetic improvement 2011

USDA-ARS?s Scientific Manuscript database

This year we produced more than 9700 liner-sized plantlets of 83 genotypes for use in greenhouse and field pest and disease resistance screening, growth in nurseries, and development of orchard trials. These included 6200 plants of 33 new Juglans microcarpa x ‘Serr’ paradox genotypes and 230 plants ...

Powdery mildew resistant cucurbit rootstocks confer tolerance to grafted susceptible watermelon scions

USDA-ARS?s Scientific Manuscript database

Cucurbit powdery mildew (PM) caused by Podosphaera xanthii can impact seedling growth and cause serious losses in greenhouse and open fields. We have developed watermelon and bottle gourd germplasm lines with high levels of resistance to PM. A PM susceptible watermelon cultivar Mickey Lee (ML) was g...

Micropropagation of apple--a review.

PubMed

Dobránszki, Judit; da Silva, Jaime A Teixeira

2010-01-01

Micropropagation of apple has played an important role in the production of healthy, disease-free plants and in the rapid multiplication of scions and rootstocks with desirable traits. During the last few decades, in apple, many reliable methods have been developed for both rootstocks and scions from a practical, commercial point of view. Successful micropropagation of apple using pre-existing meristems (culture of apical buds or nodal segments) is influenced by several internal and external factors including ex vitro (e.g. genotype and physiological state) and in vitro conditions (e.g., media constituents and light). Specific requirements during stages of micropropagation, such as the establishment of in vitro cultures, shoot multiplication, rooting of microshoots and acclimatization are summarized in this review. New approaches for increasing shoot multiplication and rooting for apple and current use of micropropagated plantlets as tools in basic and applied research are also discussed.

Periclinal chimera technique: new plant breeding approach.

PubMed

Gakpetor, P M; Mohammed, H; Moreti, D; Nassar, N M A

2017-09-21

Plant interspecific periclinal chimeras are a mosaic formed by tissues from two species. They are manipulated here as an efficient plant breeding tool for cassava root yields. In this study, plants synthesized from two chimeras, designated as chimera 2 and chimera 4, were characterized morphologically and cytologically to unravel the origin of their tissue layers (L2 and L3). Root yield of the two chimeras was also evaluated. Chimera 2 that was developed from graft union between Manihot fortalezensis (F) as scion and M. esculenta (E) as rootstock and the same in chimera 4 was developed from grafting triploid cassava cultivar (2n = 54) (C) as scion and M. pohlii (P) (2n = 36) as rootstock. A new method of inducing interspecific chimeras without using hormones was also tested in this study. Five combinations between four cassava cultivars on one side and M. fortalezensis and an interspecific hybrid (M. glaziovii x M. esculenta) on the other side were experimented to determine compatibility between the parents. Wild species always gave L2 and L3, independent of being used as rootstock or scion. L3 is responsible for producing pericycle. Thus, its performance was different in each chimera due to specific epigenetic interaction. Of 48 grafts, it was obtained one chimera giving a percentage of 2.1% that is little lower than using hormones but much efficient to use. Chimera induction efficiency in this investigation was the same when using hormones. Thus, our new, less labor, and more cost-effective technique is as much efficient as hormones and is much potential to employ as an effective plant breeding method boosting cassava root yield.

A simple and cost effective liquid culture system for the micropropagation of two commercially important apple rootstocks.

PubMed

Mehta, Mohina; Ram, Raja; Bhattacharya, Amita

2014-07-01

The two commercially important apple rootstocks i.e., MM106 and B9 were micropropagated using a liquid culture system. Three different strengths of 0.8% agar solidified PGR free basal MS medium were first tested to optimize the culture media for both the rootstocks. Full strength medium (MS0) supported maximum in vitro growth, multiplication, rooting and survival under field conditions as opposed to quarter and half strength media. When three different volumes of liquid MS0 were tested, highest in vitro growth, multiplication, rooting and also survival under field conditions were achieved in 20 mL liquid MS0. The cost of one litre of liquid medium was also reduced by 8 times to Rs. 6.29 as compared to solid medium. The cost of 20 mL medium was further reduced to Rs. 0.125.

Response of Peach Scion Cultivars and Rootstocks to Meloidogyne incognita in Vitro and in Microplots

PubMed Central

Huettel, R. N.; Hammerschlag, F. A.

1993-01-01

The response of the peach scion cultivars, Jerseyqueen, Redhaven, Compact Redhaven, and Rio Oso Gem and rootstocks 'Lovely and 'Nemaguard' to inoculation with Meloidogyne incognita was compared in vitro and in microplots. One or more parameters monitored in vitro correlated with at least one parameter monitored in microplots, 4 years after tree planting (1989). A range of responses was observed from highlysusceptible in Lovell to resistant in Nemaguard. In vitro and microplot data suggest high and moderate levels of resistance to M. incognita in Compact Redhaven and Redhaven, respectively. Both Jerseyqueen and Rio Oso Gem were susceptible to M. incognita, but not as susceptible as Lovell. The response of self-rooted peach cultivars and rootstocks to M. incognita in vitro appears to be a reliable method for predicting the reaction of each to these nematodes under field conditions. PMID:19279797

Metagenomic-based impact study of transgenic grapevine rootstock on its associated virome and soil microbiome

USDA-ARS?s Scientific Manuscript database

For some crops, the only possible approach to gain a specific trait requires genome modification. The development of virus-resistant transgenic plants based on the pathogen-derived resistance strategy has been a success story for over three decades. However, potential risks associated with the techn...

Vegetative propagation of mature and juvenile northern red oak

Treesearch

James J. Zaczek; K. C. Steiner; C. W., Jr. Heuser

1993-01-01

Rooting trials were established to evaluate rooting success of cuttings from mature and juvenile, grafted and ungrafted northern red oak (NRO). Buds from 4 mature NRO ortets and juvenile seedlings were grafted onto juvenile and mature rootstock. Cuttings were collected from the grafts and from juvenile and mature shoots developed in situ and...

Resistance to root-knot nematodes Meloidogyne spp. in woody plants.

PubMed

Saucet, Simon Bernard; Van Ghelder, Cyril; Abad, Pierre; Duval, Henri; Esmenjaud, Daniel

2016-07-01

I. 42 II. 43 III. 44 IV. 47 V. 49 VI. 50 VII. 50 VIII. 50 IX. 52 52 References 52 SUMMARY: Root-knot nematodes (RKNs) Meloidogyne spp. cause major damage to cultivated woody plants. Among them, Prunus, grapevine and coffee are the crops most infested by worldwide polyphagous species and species with a more limited distribution and/or narrower host range. The identification and characterization of natural sources of resistance are important steps to develop RKN control strategies. In woody crops, resistant rootstocks genetically different from the scion of agronomical interest may be engineered. We describe herein the interactions between RKNs and different woody crops, and highlight the plant species in which resistance and corresponding resistance (R) genes have been discovered. Even though grapevine and, to a lesser extent, coffee have a history of rootstock selection for RKN resistance, few cases of resistance have been documented. By contrast, in Prunus, R genes with different spectra have been mapped in plums, peach and almond and can be pyramided for durable resistance in interspecific rootstocks. We particularly discuss here the Ma Toll/interleukin-1 receptor-like-nucleotide binding-leucine-rich repeat gene from Myrobalan plum, one of the longest plant R genes cloned to date, due to its unique biological and structural properties. RKN R genes in Prunus will enable us to carry out molecular studies aimed at improving our knowledge of plant immunity in woody plants. © 2016 INRA. New Phytologist © 2016 New Phytologist Trust.

Susceptibility, Oviposition Preference, and Biology of Grapholita molesta (Lepidoptera: Tortricidae) in Prunus Spp. Rootstock Genotypes.

PubMed

Bernardi, D; Lazzari, J C; Andreazza, F; Mayer, N A; Botton, M; Nava, D E

2017-08-01

Studying the susceptibility of peach trees to Grapholita molesta (Busck) is one of the major steps in the development of pest-resistant peach varieties. This work evaluated the susceptibility of 55 genotypes of the "Prunus Rootstock Collection" ("Coleção Porta-enxerto de Prunus") of Embrapa Temperate Climate (Pelotas, Rio Grande do Sul, Brazil) to the natural infestation of G. molesta, assessed the oviposition preference of G. molesta in choice and no-choice bioassays, and estimated the biological parameters and the fertility life table on different Prunus spp. genotypes in the laboratory. Genotypes Prunus kansuensis (Rehder), I-67-52-9, and I-67-52-4 were the most susceptible to G. molesta infestation in the field (>60% of branches infested), while 'Sharpe' (Prunus angustifolia x Prunus spp.) and Prunus sellowii (Koehne) were the least infested (0% of branches infested). In choice and no-choice bioassays, G. molesta preferred to oviposit on P. kansuensis when compared with Sharpe. The Sharpe genotype also showed an antibiosis effect, resulting in negative effects on the fertility life table parameters when compared with the genotypes P. kansuensis and 'Capdeboscq.' The results found in the present study can provide information to initiate a long-term breeding program moving desired G. molesta resistance traits from the rootstock into the Prunus spp. cultivars. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Reproductive Variability of Field Populations of Meloidogyne spp. on Grape Rootstocks.

PubMed

Anwar, S A; McKenry, M V; Faddoul, J

2000-09-01

Variability in penetration, development, and reproduction of two resistance-breaking field pathotypes (pt.) of Meloidogyne arenaria, M. incognita, and a population of mixed Meloidogyne spp. virulent to grape hosts were compared on two resistant Vitis rootstocks 'Freedom' and 'Harmony' in separate tests. 'Cabernet Sauvignon' was included as a susceptible host to all four nematode populations. Secondstage juveniles (J2) of the mixed population failed to penetrate Freedom roots. By contrast, 6% of J2 in the M. incognita population penetrated Freedom roots but did not develop beyond the swollen J2 stage. The two resistance-breaking populations of M. arenaria differed in their virulence except on susceptible roots of Cabernet Sauvignon. More J2 of M. arenaria pt. Freedom penetrated Freedom roots and reached adult stage than did M. arenaria pt. Harmony. Later life stages of M. arenaria pt. Freedom occurred earlier and in greater numbers in Harmony roots than did M. arenaria pt. Harmony. Reproduction of M. arenaria pt. Freedom was greater in Freedom and Harmony roots than M. arenaria pt. Harmony. Thus, one population of M. arenaria is highly virulent and the other is moderately virulent.

Nuclear magnetic resonance characterization of metabolite disorder in orange trees caused by citrus sudden death disease.

PubMed

Prestes, Rosilene A; Colnago, Luiz A; Forato, Lucimara A; Carrilho, Emanuel; Bassanezi, Renato B; Wulff, Nelson A

2009-01-01

Citrus sudden death (CSD) is a new disease of sweet orange and mandarin trees grafted on Rangpur lime and Citrus volkameriana rootstocks. It was first seen in Brazil in 1999, and has since been detected in more than four million trees. The CSD causal agent is unknown and the current hypothesis involves a virus similar to Citrus tristeza virus or a new virus named Citrus sudden death-associated virus. CSD symptoms include generalized foliar discoloration, defoliation and root death, and, in most cases, it can cause tree death. One of the unique characteristics of CSD disease is the presence of a yellow stain in the rootstock bark near the bud union. This region also undergoes profound anatomical changes. In this study, we analyse the metabolic disorder caused by CSD in the bark of sweet orange grafted on Rangpur lime by nuclear magnetic resonance (NMR) spectroscopy and imaging. The imaging results show the presence of a large amount of non-functional phloem in the rootstock bark of affected plants. The spectroscopic analysis shows a high content of triacylglyceride and sucrose, which may be related to phloem blockage close to the bud union. We also propose that, without knowing the causal CSD agent, the determination of oil content in rootstock bark by low-resolution NMR can be used as a complementary method for CSD diagnosis, screening about 300 samples per hour.

Endogenous hormones response to cytokinins with regard to organogenesis in explants of peach (Prunus persica L. Batsch) cultivars and rootstocks (P. persica × Prunus dulcis).

PubMed

Pérez-Jiménez, Margarita; Cantero-Navarro, Elena; Pérez-Alfocea, Francisco; Cos-Terrer, José

2014-11-01

Organogenesis in peach (Prunus persica L. Batsch) and peach rootstocks (P. persica × Prunus dulcis) has been achieved and the action of the regeneration medium on 7 phytohormones, zeatin (Z), zeatin riboside (ZR), indole-3-acetic acid (IAA), abscisic acid (ABA), ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), salicylic acid (SA), and jasmonic acid (JA), has been studied using High performance liquid chromatography - mass spectrometry (HPLC-MS/MS). Three scion peach cultivars, 'UFO-3', 'Flariba' and 'Alice Bigi', and the peach × almond rootstocks 'Garnem' and 'GF677' were cultured in two different media, Murashige and Skoog supplemented with plant growth regulators (PGRs) (regeneration medium) and without PGRs (control medium), in order to study the effects of the media and/or genotypes in the endogenous hormones content and their role in organogenesis. The highest regeneration rate was obtained with the peach × almond rootstocks and showed a lower content of Z, IAA, ABA, ACC and JA. Only Z, ZR and IAA were affected by the action of the culture media. This study shows which hormones are external PGRs-dependent and what is the weight of the genotype and hormones in peach organogenesis that provide an avenue to manipulate in vitro organogenesis in peach. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Characterization of community structure of culturable endophytic fungi in sweet cherry composite trees and their growth-retarding effect against pathogens.

PubMed

Haddadderafshi, Neda; Pósa, Tímea Borbála; Péter, Gábor; Gáspár, László; Ladányi, Márta; Hrotkó, Károly; Lukács, Noémi; Halász, Krisztián

2016-09-01

Endophytic fungi have the potential to protect their host plants in stress situations. Characterizing the ecology and complex interaction between these endophytes and their host plants is therefore of great practical importance, particularly in horticultural plants. Among horticultural plants, fruit trees form a special category because of their longevity and because they are composites of rootstock and scion, which often belong to different plant species. Here we present the first characterization of culturable endophytic fungal community of sweet cherry. Samples from the Hungarian cultivar 'Petrus' grafted on 11 different rootstocks were collected in autumn and in spring in a bearing orchard and the dependence of colonization rate and endophyte diversity on rootstock, organ and season was analysed. On the basis of their ITS sequences 26 fungal operational taxonomic units were identified at least down to the genus level. The dominant genus, comprising more than 50% of all isolates, was Alternaria, followed by different Fusarium and Epicoccum species. We observed some organ-specificity amongst endophytes, and organs showed more sizeable differences in colonization rates and endophyte diversity than rootstocks. Most dynamic endophyte populations, strongly influenced by environmental conditions and crop management, were observed in leaves. The potential of selected endophytes to confer protection against Monilinia laxa was also analysed and 7 isolates were found to inhibit the growth of this pathogen in vitro.

Relationships between nutrient composition of flowers and fruit quality in orange trees grown in calcareous soil.

PubMed

Pestana, Maribela; Beja, Pedro; Correia, Pedro José; de Varennes, Amarilis; Faria, Eugénio Araújo

2005-06-01

To determine if flower nutrient composition can be used to predict fruit quality, a field experiment was conducted over three seasons (1996-1999) in a commercial orange orchard (Citrus sinensis (L.) Osbeck cv. 'Valencia Late', budded on Troyer citrange rootstock) established on a calcareous soil in southern Portugal. Flowers were collected from 20 trees during full bloom in April and their nutrient composition determined, and fruits were harvested the following March and their quality evaluated. Patterns of covariation in flower nutrient concentrations and in fruit quality variables were evaluated by principal component analysis. Regression models relating fruit quality variables to flower nutrient composition were developed by stepwise selection procedures. The predictive power of the regression models was evaluated with an independent data set. Nutrient composition of flowers at full bloom could be used to predict the fruit quality variables fresh fruit mass and maturation index in the following year. Magnesium, Ca and Zn concentrations measured in flowers were related to fruit fresh mass estimations and N, P, Mg and Fe concentrations were related to fruit maturation index. We also established reference values for the nutrient composition of flowers based on measurements made in trees that produced large (> 76 mm in diameter) fruit.

Testing the potential significance of different scion/rootstock genotype combinations on the ecology of old cultivated olive trees in the southeast Mediterranean area.

PubMed

Barazani, Oz; Waitz, Yoni; Tugendhaft, Yizhar; Dorman, Michael; Dag, Arnon; Hamidat, Mohammed; Hijawi, Thameen; Kerem, Zohar; Westberg, Erik; Kadereit, Joachim W

2017-02-06

A previous multi-locus lineage (MLL) analysis of SSR-microsatellite data of old olive trees in the southeast Mediterranean area had shown the predominance of the Souri cultivar (MLL1) among grafted trees. The MLL analysis had also identified an MLL (MLL7) that was more common among rootstocks than other MLLs. We here present a comparison of the MLL combinations MLL1 (scion)/MLL7 (rootstock) and MLL1/MLL1 in order to investigate the possible influence of rootstock on scion phenotype. A linear regression analysis demonstrated that the abundance of MLL1/MLL7 trees decreases and of MLL1/MLL1 trees increases along a gradient of increasing aridity. Hypothesizing that grafting on MLL7 provides an advantage under certain conditions, Akaike information criterion (AIC) model selection procedure was used to assess the influence of different environmental conditions on phenotypic characteristics of the fruits and oil of the two MLL combinations. The most parsimonious models indicated differential influences of environmental conditions on parameters of olive oil quality in trees belonging to the MLL1/MLL7 and MLL1/MLL1 combinations, but a similar influence on fruit characteristics and oil content. These results suggest that in certain environments grafting of the local Souri cultivar on MLL7 rootstocks and the MLL1/MLL1 combination result in improved oil quality. The decreasing number of MLL1/MLL7 trees along an aridity gradient suggests that use of this genotype combination in arid sites was not favoured because of sensitivity of MLL7 to drought. Our results thus suggest that MLL1/MLL7 and MLL1/MLL1 combinations were selected by growers in traditional rain-fed cultivation under Mediterranean climate conditions in the southeast Mediterranean area.

Mathematical Modeling and Optimizing of in Vitro Hormonal Combination for G × N15 Vegetative Rootstock Proliferation Using Artificial Neural Network-Genetic Algorithm (ANN-GA)

PubMed Central

Arab, Mohammad M.; Yadollahi, Abbas; Ahmadi, Hamed; Eftekhari, Maliheh; Maleki, Masoud

2017-01-01

The efficiency of a hybrid systems method which combined artificial neural networks (ANNs) as a modeling tool and genetic algorithms (GAs) as an optimizing method for input variables used in ANN modeling was assessed. Hence, as a new technique, it was applied for the prediction and optimization of the plant hormones concentrations and combinations for in vitro proliferation of Garnem (G × N15) rootstock as a case study. Optimizing hormones combination was surveyed by modeling the effects of various concentrations of cytokinin–auxin, i.e., BAP, KIN, TDZ, IBA, and NAA combinations (inputs) on four growth parameters (outputs), i.e., micro-shoots number per explant, length of micro-shoots, developed callus weight (CW) and the quality index (QI) of plantlets. Calculation of statistical values such as R2 (coefficient of determination) related to the accuracy of ANN-GA models showed a considerably higher prediction accuracy for ANN models, i.e., micro-shoots number: R2 = 0.81, length of micro-shoots: R2 = 0.87, CW: R2 = 0.88, QI: R2 = 0.87. According to the results, among the input variables, BAP (19.3), KIN (9.64), and IBA (2.63) showed the highest values of variable sensitivity ratio for proliferation rate. The GA showed that media containing 1.02 mg/l BAP in combination with 0.098 mg/l IBA could lead to the optimal proliferation rate (10.53) for G × N15 rootstock. Another objective of the present study was to compare the performance of predicted and optimized cytokinin–auxin combination with the best optimized obtained concentrations of our other experiments. Considering three growth parameters (length of micro-shoots, micro-shoots number, and proliferation rate), the last treatment was found to be superior to the rest of treatments for G × N15 rootstock in vitro multiplication. Very little difference between the ANN predicted and experimental data confirmed high capability of ANN-GA method in predicting new optimized protocols for plant in vitro propagation. PMID:29163583

Are commercial sweet cherry rootstocks adapted to climate change? Short-term waterlogging and CO2 effects on sweet cherry cv. 'Burlat'.

PubMed

Pérez-Jiménez, Margarita; Hernández-Munuera, María; Piñero, M Carmen; López-Ortega, Gregorio; Del Amor, Francisco M

2018-05-01

High CO 2 is able to ameliorate some negative effects due to climate change and intensify others. This study involves the sweet cherry (Prunus avium) cultivar 'Burlat' grafted on the 'Mariana 2624', 'Adara' and 'LC 52' rootstocks. In a climate chamber at two CO 2 concentrations, ambient (400 µmol mol -1 ) and elevated (800 µmol mol -1 ), the plants were submitted to waterlogging for 7 d, followed by 7 d of recovery after drainage. Waterlogging drastically decreased the rate of photosynthesis, significantly endangering plant survival, particularly for the 'LC 52' and 'Adara' rootstocks. 'Mariana 2624' was also clearly affected by waterlogging that increased lipid peroxidation and the Cl - and SO 4 2- concentrations in all the studied plants. Nevertheless, CO 2 was able to overcome this reduction in photosynthesis, augmenting growth, increasing soluble sugars and starch, raising turgor and regulating the concentrations of Cl - and SO 4 2- , while lowering the NO 3 - concentration in leaves of all the studied rootstocks. In concordance with these results, the proline levels indicated a more intense stress at control CO 2 than at high CO 2 for waterlogged plants. 'Mariana 2624' was more resistant to waterlogging than 'Adara', and both were more resistant than 'LC 52' in control CO 2 conditions; this clearly enhanced the chance of survival under hypoxia. © 2017 John Wiley & Sons Ltd.

Molecular Characterization of the Meyer Lemon Isolate of Citrus Tatter Leaf Virus: Complete Genome Sequence and Development of Biologically Active In Vitro Transcripts

USDA-ARS?s Scientific Manuscript database

Citrus tatter leaf virus isolated from Meyer lemon trees (CTLV-ML) from California and Florida induces bud union incompatibility of citrus trees grafted on the widely used trifoliate and trifoliate hybrid rootstocks. The complete genome sequence of CTLV-ML was determined to be 6,495 nucleotides (nts...

A dark incubation period is important for Agrobacterium-mediated transformation of mature internode explants of sweet orange, grapefruit, citron, and a citrange rootstock

USDA-ARS?s Scientific Manuscript database

Background: Citrus has an extended juvenile phase and trees can take 2-20 years to transition to the adult reproductive phase and produce fruit. For citrus variety development this substantially prolongs the time before adult traits, such as fruit yield and quality, can be evaluated. Methods to...

Using Perls Staining to Trace the Iron Uptake Pathway in Leaves of a Prunus Rootstock Treated with Iron Foliar Fertilizers

PubMed Central

Rios, Juan J.; Carrasco-Gil, Sandra; Abadía, Anunciación; Abadía, Javier

2016-01-01

The aim of this study was to trace the Fe uptake pathway in leaves of Prunus rootstock (GF 677; Prunus dulcis × Prunus persica) plants treated with foliar Fe compounds using the Perls blue method, which detects labile Fe pools. Young expanded leaves of Fe-deficient plants grown in nutrient solution were treated with Fe-compounds using a brush. Iron compounds used were the ferrous salt FeSO4, the ferric salts Fe2(SO4)3 and FeCl3, and the chelate Fe(III)-EDTA, all of them at concentrations of 9 mM Fe. Leaf Fe concentration increases were measured at 30, 60, 90 min, and 24 h, and 70 μm-thick leaf transversal sections were obtained with a vibrating microtome and stained with Perls blue. In vitro results show that the Perls blue method is a good tool to trace the Fe uptake pathway in leaves when using Fe salts, but is not sensitive enough when using synthetic Fe(III)-chelates such as Fe(III)-EDTA and Fe(III)-IDHA. Foliar Fe fertilization increased leaf Fe concentrations with all Fe compounds used, with inorganic Fe salts causing larger leaf Fe concentration increases than Fe(III)-EDTA. Results show that Perls blue stain appeared within 30 min in the stomatal areas, indicating that Fe applied as inorganic salts was taken up rapidly via stomata. In the case of using FeSO4 a progression of the stain was seen with time toward vascular areas in the leaf blade and the central vein, whereas in the case of Fe(III) salts the stain mainly remained in the stomatal areas. Perls stain was never observed in the mesophyll areas, possibly due to the low concentration of labile Fe pools. PMID:27446123

Roostocks/Scion/Nitrogen Interactions Affect Secondary Metabolism in the Grape Berry

PubMed Central

Habran, Aude; Commisso, Mauro; Helwi, Pierre; Hilbert, Ghislaine; Negri, Stefano; Ollat, Nathalie; Gomès, Eric; van Leeuwen, Cornelis; Guzzo, Flavia; Delrot, Serge

2016-01-01

The present work investigates the interactions between soil content, rootstock, and scion by focusing on the effects of roostocks and nitrogen supply on grape berry content. Scions of Cabernet Sauvignon (CS) and Pinot Noir (PN) varieties were grafted either on Riparia Gloire de Montpellier (RGM) or 110 Richter (110R) rootstock. The 4 rooststock/scion combinations were fertilized with 3 different levels of nitrogen after fruit set. Both in 2013 and 2014, N supply increased N uptake by the plants, and N content both in vegetative and reproductory organs. Rootstock, variety and year affected berry weight at harvest, while nitrogen did not affect significantly this parameter. Grafting on RGM consistently increased berry weight compared to 110R. PN consistently produced bigger berries than CS. CS berries were heavier in 2014 than in 2013, but the year effect was less marked for PN berries. The berries were collected between veraison and maturity, separated in skin and pulp, and their content was analyzed by conventional analytical procedures and untargeted metabolomics. For anthocyanins, the relative quantitation was fairly comparable with both LC-MS determination and HPLC-DAD, which is a fully quantitative technique. The data show complex responses of the metabolite content (sugars, organic acids, amino acids, anthocyanins, flavonols, flavan-3-ols/procyanidins, stilbenes, hydroxycinnamic, and hydroxybenzoic acids) that depend on the rootstock, the scion, the vintage, the nitrogen level, the berry compartment. This opens a wide range of possibilities to adjust the content of these compounds through the choice of the roostock, variety and nitrogen fertilization. PMID:27555847

Roostocks/Scion/Nitrogen Interactions Affect Secondary Metabolism in the Grape Berry.

PubMed

Habran, Aude; Commisso, Mauro; Helwi, Pierre; Hilbert, Ghislaine; Negri, Stefano; Ollat, Nathalie; Gomès, Eric; van Leeuwen, Cornelis; Guzzo, Flavia; Delrot, Serge

2016-01-01

The present work investigates the interactions between soil content, rootstock, and scion by focusing on the effects of roostocks and nitrogen supply on grape berry content. Scions of Cabernet Sauvignon (CS) and Pinot Noir (PN) varieties were grafted either on Riparia Gloire de Montpellier (RGM) or 110 Richter (110R) rootstock. The 4 rooststock/scion combinations were fertilized with 3 different levels of nitrogen after fruit set. Both in 2013 and 2014, N supply increased N uptake by the plants, and N content both in vegetative and reproductory organs. Rootstock, variety and year affected berry weight at harvest, while nitrogen did not affect significantly this parameter. Grafting on RGM consistently increased berry weight compared to 110R. PN consistently produced bigger berries than CS. CS berries were heavier in 2014 than in 2013, but the year effect was less marked for PN berries. The berries were collected between veraison and maturity, separated in skin and pulp, and their content was analyzed by conventional analytical procedures and untargeted metabolomics. For anthocyanins, the relative quantitation was fairly comparable with both LC-MS determination and HPLC-DAD, which is a fully quantitative technique. The data show complex responses of the metabolite content (sugars, organic acids, amino acids, anthocyanins, flavonols, flavan-3-ols/procyanidins, stilbenes, hydroxycinnamic, and hydroxybenzoic acids) that depend on the rootstock, the scion, the vintage, the nitrogen level, the berry compartment. This opens a wide range of possibilities to adjust the content of these compounds through the choice of the roostock, variety and nitrogen fertilization.

[Citrus boron nutrient level and its impact factors in the Three Gorges Reservoir region of Chongqing, China].

PubMed

Zhou, Wei; Peng, Liang-Zhi; Chun, Chang-Pin; Jiang, Cai-Lun; Ling, Li-Li; Wang, Nan-Qi; Xing, Fei; Huang, Yi

2014-04-01

To investigate the level of boron nutrient in citrus and its impact factors, a total of 954 citrus leaf samples and 302 soil samples were collected from representative orchards in the 12 main citrus production counties in the Three Gorges Reservoir region of Chongqing to determine the boron content in citrus leaves, as well as the relationships between leaf boron content with soil available boron content, soil pH value, cultivar, rootstock and the age of tree. Results indicated that the leaf samples from 41.6% orchards (< 35 mg x kg(-1)) and the soil samples from 89.4% orchards (< 0.5 mg x kg(-1)) were boron insufficient. The correlation of leaf boron content and soil available boron content was not significant. The soil pH, cultivar, rootstock and the age of tree did affect the leaf boron content. The leaves from the orchards with soil pH of 4.5-6.4 demonstrated significantly higher boron contents than with the soil pH of 6.5-8.5. The leaf boron contents in the different cultivars was ranged as Satsuma mandarin > pomelo > valencia orange > sweet orange > tangor > navel orange. The citrus on trifoliate orange and sour pomelo rootstocks had significantly higher leaf boron contents than on Carrizo citrange and red tangerine rootstocks. Compared with the adult citrus trees (above 8 year-old), 6.6% more of leaf samples of younger trees (3 to 8 year-old) contained boron contents in the optimum range (35-100 mg x kg(-1)).

EXO70A1-mediated vesicle trafficking is critical for tracheary element development in Arabidopsis.

PubMed

Li, Shipeng; Chen, Min; Yu, Dali; Ren, Shichao; Sun, Shufeng; Liu, Linde; Ketelaar, Tijs; Emons, Anne-Mie C; Liu, Chun-Ming

2013-05-01

Exocysts are highly conserved octameric complexes that play an essential role in the tethering of Golgi-derived vesicles to target membranes in eukaryotic organisms. Genes encoding the EXO70 subunit are highly duplicated in plants. Based on expression analyses, we proposed previously that individual EXO70 members may provide the exocyst with functional specificity to regulate cell type- or cargo-specific exocytosis, although direct evidence is not available. Here, we show that, as a gene expressed primarily during tracheary element (TE) development, EXO70A1 regulates vesicle trafficking in TE differentiation in Arabidopsis thaliana. Mutations of EXO70A1 led to aberrant xylem development, producing dwarfed and nearly sterile plants with very low fertility, reduced cell expansion, and decreased water potential and hydraulic transport. Grafting of a mutant shoot onto wild-type rootstock rescued most of these aboveground phenotypes, while grafting of a wild-type shoot to the mutant rootstock did not rescue the short root hair phenotype, consistent with the role of TEs in hydraulic transport from roots to shoots. Histological analyses revealed an altered pattern of secondary cell wall thickening and accumulation of large membrane-bound compartments specifically in developing TEs of the mutant. We thus propose that EXO70A1 functions in vesicle trafficking in TEs to regulate patterned secondary cell wall thickening.

HR-MAS NMR metabolomics of 'Swingle' citrumelo rootstock genetically modified to overproduce proline.

PubMed

de Oliveira, Caroline S; Carlos, Eduardo F; Vieira, Luiz G E; Lião, Luciano M; Alcantara, Glaucia B

2014-08-01

The accumulation of proline is a typical physiological response to abiotic stresses in higher plants. 'Swingle' citrumelo, an important rootstock for citrus production, has been modified with a mutated Δ(1)-pyrroline-5-carboxylate synthetase gene (VaP5CSF129A) linked to the cauliflower mosaic virus 35S promoter to induce the overproduction of free proline. This paper presents a comparative metabolomic study of nontransgenic versus transgenic 'Swingle' citrumelo plants with high endogenous proline. (1)H high-resolution magic angle spinning nuclear magnetic resonance spectroscopy and multivariate analysis showed significant differences in some metabolites between the nontransgenic and transgenic leaves and roots. The overproduction of proline has reduced the sucrose content in transgenic leaves, revealing a metabolic cost for these plants. In roots, the high level of free proline acts for the adjustment of cation-anion balance, causing the reduction of acetic acid content. The same sucrose level in roots indicates that they can be considered as sucrose sink. Similar behavior may be waited for fruits produced on transgenic rootstock. Copyright © 2014 John Wiley & Sons, Ltd.

The MdTFL1 gene of apple (Malus x domestica Borkh.) reduces vegetative growth and generation time.

PubMed

Flachowsky, Henryk; Szankowski, Iris; Waidmann, Sascha; Peil, Andreas; Tränkner, Conny; Hanke, Magda-Viola

2012-10-01

TFL1 is known as a floral repressor in Arabidopsis thaliana (L.) Heynh. In apple there are two TFL1 homologs, MdTFL1-1 and MdTFL1-2. The MdTFL1-1 gene was silenced in transgenic clones expressing a hairpin gene construct of a 323 bp fragment of MdTFL1-1. The hairpin gene construct was transferred to three different apple genotypes. Of 22 transgenic clones, 21 showed a significant reduction in MdTFL1-1 mRNA expression. Precocious flowering was obtained for 20 clones, which flowered already during in vitro cultivation. Nineteen clones could successfully be transferred to the greenhouse where 18 of them flowered within a few weeks followed by the death or at least a strongly inhibited vegetative growth of the plant. Most of the transgenic flowers developed abnormally. Results obtained on greenhouse-grown plants of the transgenic clones and transgenic seedlings clearly demonstrated the major role of MdTFL1 genes in maintaining the vegetative growth as prerequisite for a perennial lifecycle. It was shown that MdTFL1 dsRNAi promotes a life history similar to annual plants. Preliminary results obtained from grafting experiments with non-transgenic scions grafted onto MdTFL1 dsRNAi transgenic rootstocks indicated that the flower-inducing signal obtained after silencing of MdTFL1 genes seems not to be graft-transmissible.

SNP markers tightly linked to root knot nematode resistance in grapevine (Vitis cinerea) identified by a genotyping-by-sequencing approach followed by Sequenom MassARRAY validation

PubMed Central

Morales, Norma B.; Moskwa, Sam; Clingeleffer, Peter R.; Thomas, Mark R.

2018-01-01

Plant parasitic nematodes, including root knot nematode Meloidogyne species, cause extensive damage to agriculture and horticultural crops. As Vitis vinifera cultivars are susceptible to root knot nematode parasitism, rootstocks resistant to these soil pests provide a sustainable approach to maintain grapevine production. Currently, most of the commercially available root knot nematode resistant rootstocks are highly vigorous and take up excess potassium, which reduces wine quality. As a result, there is a pressing need to breed new root knot nematode resistant rootstocks, which have no impact on wine quality. To develop molecular markers that predict root knot nematode resistance for marker assisted breeding, a genetic approach was employed to identify a root knot nematode resistance locus in grapevine. To this end, a Meloidogyne javanica resistant Vitis cinerea accession was crossed to a susceptible Vitis vinifera cultivar Riesling and results from screening the F1 individuals support a model that root knot nematode resistance, is conferred by a single dominant allele, referred as MELOIDOGYNE JAVANICA RESISTANCE1 (MJR1). Further, MJR1 resistance appears to be mediated by a hypersensitive response that occurs in the root apical meristem. Single nucleotide polymorphisms (SNPs) were identified using genotyping-by-sequencing and results from association and genetic mapping identified the MJR1 locus, which is located on chromosome 18 in the Vitis cinerea accession. Validation of the SNPs linked to the MJR1 locus using a Sequenom MassARRAY platform found that only 50% could be validated. The validated SNPs that flank and co-segregate with the MJR1 locus can be used for marker-assisted selection for Meloidogyne javanica resistance in grapevine. PMID:29462210

SNP markers tightly linked to root knot nematode resistance in grapevine (Vitis cinerea) identified by a genotyping-by-sequencing approach followed by Sequenom MassARRAY validation.

PubMed

Smith, Harley M; Smith, Brady P; Morales, Norma B; Moskwa, Sam; Clingeleffer, Peter R; Thomas, Mark R

2018-01-01

Plant parasitic nematodes, including root knot nematode Meloidogyne species, cause extensive damage to agriculture and horticultural crops. As Vitis vinifera cultivars are susceptible to root knot nematode parasitism, rootstocks resistant to these soil pests provide a sustainable approach to maintain grapevine production. Currently, most of the commercially available root knot nematode resistant rootstocks are highly vigorous and take up excess potassium, which reduces wine quality. As a result, there is a pressing need to breed new root knot nematode resistant rootstocks, which have no impact on wine quality. To develop molecular markers that predict root knot nematode resistance for marker assisted breeding, a genetic approach was employed to identify a root knot nematode resistance locus in grapevine. To this end, a Meloidogyne javanica resistant Vitis cinerea accession was crossed to a susceptible Vitis vinifera cultivar Riesling and results from screening the F1 individuals support a model that root knot nematode resistance, is conferred by a single dominant allele, referred as MELOIDOGYNE JAVANICA RESISTANCE1 (MJR1). Further, MJR1 resistance appears to be mediated by a hypersensitive response that occurs in the root apical meristem. Single nucleotide polymorphisms (SNPs) were identified using genotyping-by-sequencing and results from association and genetic mapping identified the MJR1 locus, which is located on chromosome 18 in the Vitis cinerea accession. Validation of the SNPs linked to the MJR1 locus using a Sequenom MassARRAY platform found that only 50% could be validated. The validated SNPs that flank and co-segregate with the MJR1 locus can be used for marker-assisted selection for Meloidogyne javanica resistance in grapevine.

Root-soil relationships and terroir

NASA Astrophysics Data System (ADS)

Tomasi, Diego

2015-04-01

Soil features, along with climate, are among the most important determinants of a succesful grape production in a certain area. Most of the studies, so far, investigated the above-ground vine response to differente edaphic and climate condition, but it is clearly not sufficient to explain the vine whole behaviour. In fact, roots represent an important part of the terroir system (soil-plant-atmosphere-man), and their study can provide better comprehension of vine responses to different environments. The root density and distribution, the ability of deep-rooting and regenerating new roots are good indicators of root well-being, and represents the basis for an efficient physiological activity of the root system. Root deepening and distribution are strongly dependent and sensitive on soil type and soil properties, while root density is affected mostly by canopy size, rootstock and water availability. According to root well-being, soil management strategies should alleviate soil impediments, improving aeration and microbial activity. Moreover, agronomic practices can impact root system performance and influence the above-ground growth. It is well known, for example, that the root system size is largely diminished by high planting densities. Close vine spacings stimulate a more effective utilization of the available soil, water and nutrients, but if the competition for available soil becomes too high, it can repress vine growth, and compromise vineyard longevity, productivity and reaction to growing season weather. Development of resilient rootstocks, more efficient in terms of water and nutrient uptake and capable of dealing with climate and soil extremes (drought, high salinity) are primary goals fore future research. The use of these rootstocks will benefit a more sustainable use of the soil resources and the preservation and valorisation of the terroir.

Insights into the Vitis complex in the Danube floodplain (Austria).

PubMed

Arnold, Claire; Bachmann, Olivier; Schnitzler, Annik

2017-10-01

European grapevine populations quickly disappeared from most of their range, massively killed by the spread of North American grapevine pests and diseases. Nowadays taxonomic pollution represents a new threat. A large Vitis complex involves escaped cultivars, rootstocks, and wild grapevines. The study aimed to provide insight into the Vitis complex in the Danube region through field and genetic analyses. Among the five other major rivers in Europe which still host wild grapevine populations, the Danube floodplain is the only one benefiting from an extensive protected forest area (93 km²) and an relatively active dynamic flood pulse. The Donau-Auen National Park also regroups the largest wild grapevine population in Europe. Ninety-two percent of the individuals collected in the park were true wild grapevines, and 8% were hybrids and introgressed individuals of rootstocks, wild grapevines, and cultivars. These three groups are interfertile acting either as pollen donor or receiver. Hybrids were established within and outside the dykes, mostly in anthropized forest edges. The best-developed individuals imply rootstock genes. They establish in the most erosive parts of the floodplain. 42% of the true wild grapevines lived at the edges of forest/meadow, 33.3% at the edges forest/channels, and 23.9% in forest gaps. DBH (Diameter Breast Height) varied significantly with the occurrence of flooding. Clones were found in both true wild and hybrids/introgressed grapevines. The process of cloning seemed to be prevented in places where flooding dynamics is reduced. The current global distribution of true wild grapevines shows a strong tendency toward clustering, in sites where forestry practices were the most extensive. However, the reduced flooding activity is a danger for long-term sustainability of the natural wild grapevine population.

Involvement of ethylene in sex expression and female flower development in watermelon (Citrullus lanatus).

PubMed

Manzano, Susana; Martínez, Cecilia; García, Juan Manuel; Megías, Zoraida; Jamilena, Manuel

2014-12-01

Although it is known that ethylene has a masculinizing effect on watermelon, the specific role of this hormone in sex expression and flower development has not been analyzed in depth. By using different approaches the present work demonstrates that ethylene regulates differentially two sex-related developmental processes: sexual expression, i.e. the earliness and the number of female flowers per plant, and the development of individual floral buds. Ethylene production in the shoot apex as well as in male, female and bisexual flowers demonstrated that the female flower requires much more ethylene than the male one to develop, and that bisexual flowers result from a decrease in ethylene production in the female floral bud. The occurrence of bisexual flowers was found to be associated with elevated temperatures in the greenhouse, concomitantly with a reduction of ethylene production in the shoot apex. External treatments with ethephon and AVG, and the use of Cucurbita rootstocks with different ethylene production and sensitivity, confirmed that, as occurs in other cucurbit species, ethylene is required to arrest the development of stamens in the female flower. Nevertheless, in watermelon ethylene inhibits the transition from male to female flowering and reduces the number of pistillate flowers per plant, which runs contrary to findings in other cucurbit species. The use of Cucurbita rootstocks with elevated ethylene production delayed the production of female flowers but reduced the number of bisexual flowers, which is associated with a reduced fruit set and altered fruit shape.

The Accumulation of miRNAs Differentially Modulated by Drought Stress Is Affected by Grafting in Grapevine1[OPEN

PubMed Central

Vitali, Marco; Vitulo, Nicola; Incarbone, Marco

2017-01-01

Grapevine (Vitis vinifera) is routinely grafted, and rootstocks inducing drought tolerance represent a source for adapting vineyards to climate change in temperate areas. Our goal was to investigate drought stress effects on microRNA (miRNA) abundance in a drought-resistant grapevine rootstock, M4 (Vitis vinifera × Vitis berlandieri), compared with a commercial cultivar, Cabernet Sauvignon, using their autografts and reciprocal grafts. RNA extracted from roots and leaves of droughted and irrigated plants of different graft combinations was used to prepare cDNA libraries for small RNA sequencing and to analyze miRNAs by quantitative real-time polymerase chain reaction (RT-qPCR). Measurements of leaf water potential, leaf gas exchange, and root hydraulic conductance attested that, under irrigation, M4 reduced water loss in comparison with cultivar Cabernet Sauvignon mostly through nonhydraulic, root-specific mechanisms. Under drought, stomatal conductance decreased at similar levels in the two genotypes. Small RNA sequencing allowed the identification of 70 conserved miRNAs and the prediction of 28 novel miRNAs. Different accumulation trends of miRNAs, observed upon drought and in different genotypes and organs, were confirmed by RT-qPCR. Corresponding target transcripts, predicted in silico and validated by RT-qPCR, often showed opposite expression profiles than the related miRNAs. Drought effects on miRNA abundance differed between the two genotypes. Furthermore, the concentration of drought-responsive miRNAs in each genotype was affected by reciprocal grafting, suggesting either the movement of signals inducing miRNA expression in the graft partner or, possibly, miRNA transport between scion and rootstock. These results open new perspectives in the selection of rootstocks for improving grapevine adaptation to drought. PMID:28235889

Tests for Transmission of Prunus Necrotic Ringspot and Two Nepoviruses by Criconemella xenoplax

PubMed Central

Yuan, W-Q.; Barnett, O. W.; Westcott, S. W.; Scott, S. W.

1990-01-01

In two of three trials, detectable color reactions in ELISA for Prunus necrotic ringspot virus (PNRSV) were observed for Criconemella xenoplax handpicked from the root zone of infected peach trees. Criconemella xenoplax (500/pot) handpicked from root zones of peach trees infected with PNRSV failed to transmit the virus to cucumber or peach seedlings. The nematode also failed to transmit tomato ringspot (TomRSV) or tobacco ringspot viruses between cucumbers, although Xiphinema americanum transmitted TomRSV under the same conditions. Plants of peach, cucumber, Chenopodium quinoa, and Catharanthus roseus were not infected by PNRSV when grown in soil containing C. xenoplax collected from root zones of PNRSV-infected trees. Shirofugen cherry scions budded on Mazzard cherry seedling rootstocks remained symptomless when transplanted into root zones of PNRSV-infected trees. Virus transmission was not detected by ELISA when C. xenoplax individuals were observed to feed on cucumber root explants that were infected with PNRSV and subsequently fed on roots of Prunus besseyi in agar cultures. Even if virus transmission by C. xenoplax occurs via contamination rather than by a specific mechanism, it must be rare. PMID:19287748

Tests for Transmission of Prunus Necrotic Ringspot and Two Nepoviruses by Criconemella xenoplax.

PubMed

Yuan, W Q; Barnett, O W; Westcott, S W; Scott, S W

1990-10-01

In two of three trials, detectable color reactions in ELISA for Prunus necrotic ringspot virus (PNRSV) were observed for Criconemella xenoplax handpicked from the root zone of infected peach trees. Criconemella xenoplax (500/pot) handpicked from root zones of peach trees infected with PNRSV failed to transmit the virus to cucumber or peach seedlings. The nematode also failed to transmit tomato ringspot (TomRSV) or tobacco ringspot viruses between cucumbers, although Xiphinema americanum transmitted TomRSV under the same conditions. Plants of peach, cucumber, Chenopodium quinoa, and Catharanthus roseus were not infected by PNRSV when grown in soil containing C. xenoplax collected from root zones of PNRSV-infected trees. Shirofugen cherry scions budded on Mazzard cherry seedling rootstocks remained symptomless when transplanted into root zones of PNRSV-infected trees. Virus transmission was not detected by ELISA when C. xenoplax individuals were observed to feed on cucumber root explants that were infected with PNRSV and subsequently fed on roots of Prunus besseyi in agar cultures. Even if virus transmission by C. xenoplax occurs via contamination rather than by a specific mechanism, it must be rare.

Molecular Basis of Citrus sunki Susceptibility and Poncirus trifoliata Resistance Upon Phytophthora parasitica Attack.

PubMed

Dalio, Ronaldo José Durigan; Máximo, Heros José; Oliveira, Tiago Silva; Azevedo, Thamara de Medeiros; Felizatti, Henrique Leme; Campos, Magnólia de Araújo; Machado, Marcos Antonio

2018-03-01

Coevolution has shaped the molecular basis of an extensive number of defense mechanisms in plant-pathogen interactions. Phytophthora parasitica, a hemibiothrophic oomycete pathogen and the causal agent of citrus root rot and gummosis, interacts differently with Citrus sunki and Poncirus trifoliata, two commonly favored citrus rootstocks that are recognized as susceptible and resistant, respectively, to P. parasitica. The molecular core of these interactions remains elusive. Here, we provide evidence on the defense strategies employed by both susceptible and resistant citrus rootstocks, in parallel with P. parasitica deployment of effectors. Time course expression analysis (quantitative real-time polymerase chain reaction) of several defense-related genes were evaluated during i) plant disease development, ii) necrosis, and iii) pathogen effector gene expression. In C. sunki, P. parasitica deploys effectors, including elicitins, NPP1 (necrosis-inducing Phytophthora protein 1), CBEL (cellulose-binding elicitor and lectin activity), RxLR, and CRN (crinkler), and, consequently, this susceptible plant activates its main defense signaling pathways that result in the hypersensitive response and necrosis. Despite the strong plant-defense response, it fails to withstand P. parasitica invasion, confirming its hemibiothrophic lifestyle. In Poncirus trifoliata, the effectors were strongly expressed, nevertheless failing to induce any immunity manipulation and disease development, suggesting a nonhost resistance type, in which the plant relies on preformed biochemical and anatomical barriers.

Virulence of Meloidogyne spp. and Induced Resistance in Grape Rootstocks.

PubMed

McKenry, Michael V; Anwar, Safdar A

2007-03-01

Harmony grape rootstock displays resistance to several Meloidogyne spp. but that resistance is not durable in commercial vineyard settings. A 2-year experiment in a microplot setting revealed host specificities of two virulent populations of Meloidogyne arenaria and an avirulent population of Meloidogyne incognita. In a subsequent split-root experiment, the avirulent nematode population was demonstrated to induce resistance to the virulent nematode population. To quantify the level of resistance, reproduction of the virulent nematode population was determined 63 days after being challenged by an avirulent nematode population using a range of inoculum densities and timeframes. Induction of resistance became apparent when the virulent nematode population was inoculated 7 days after the avirulent nematode population and increased thereafter. The level of induced resistance increased with increased inoculum levels of the avirulent nematode population. Root systems of perennial crops are commonly fed upon simultaneously by multiple nematode species. These two studies indicate that field populations can become preferentially virulent upon one or multiple rootstocks and that co-inhabiting populations may induce existing resistance mechanisms. In perennial crops, it is common for numerous nematode species besides Meloidogyne spp. to be present, including some that feed without causing apparent damage.

Unraveling Main Limiting Sites of Photosynthesis under Below- and Above-Ground Heat Stress in Cucumber and the Alleviatory Role of Luffa Rootstock.

PubMed

Li, Hao; Ahammed, Golam J; Zhou, Guona; Xia, Xiaojian; Zhou, Jie; Shi, Kai; Yu, Jingquan; Zhou, Yanhong

2016-01-01

Photosynthesis is one of the most thermo-sensitive processes in plants. Although the severity of heat stress could be attenuated by grafting approach, the primary damaged site of photosynthesis system under heat stress and the regulatory mechanism of rootstock-mediated heat tolerance are poorly understood. In the current study, cucumber plants grafted onto their own roots and heat-tolerant luffa roots were exposed to root-zone heat (25/40°C) and aerial heat (40/25°C) individually and in combination (40/40°C) to understand the response of photosynthetic process by investigating energy absorption and distribution, electron transport in photosystem (PS) II and I, and CO2 assimilation. According to the results, root-zone heat stress inhibited photosynthesis mainly through decreasing Rubisco activity, while aerial heat stress mainly through inhibiting PSII acceptor side. The imbalance in light absorption and utilization resulted in accumulation of reactive oxygen species that caused damage to photosynthetic apparatus, forming a vicious cycle. On the contrary, grafting cucumber onto heat-tolerant luffa rootstock alleviated heat-induced photosynthetic inhibition and oxidative stress by maintaining higher root vitality, HSP70 accumulation, and antioxidant potential.

Grafting cucumber onto luffa improves drought tolerance by increasing ABA biosynthesis and sensitivity

PubMed Central

Liu, Shanshan; Li, Hao; Lv, Xiangzhang; Ahammed, Golam Jalal; Xia, Xiaojian; Zhou, Jie; Shi, Kai; Asami, Tadao; Yu, Jingquan; Zhou, Yanhong

2016-01-01

Balancing stomata-dependent CO2 assimilation and transpiration is a key challenge for increasing crop productivity and water use efficiency under drought stress for sustainable crop production worldwide. Here, we show that cucumber and luffa plants with luffa as rootstock have intrinsically increased water use efficiency, decreased transpiration rate and less affected CO2 assimilation capacity following drought stress over those with cucumber as rootstock. Drought accelerated abscisic acid (ABA) accumulation in roots, xylem sap and leaves, and induced the transcript of ABA signaling genes, leading to a decreased stomatal aperture and transpiration in the plants grafted onto luffa roots as compared to plants grafted onto cucumber roots. Furthermore, stomatal movement in the plants grafted onto luffa roots had an increased sensitivity to ABA. Inhibition of ABA biosynthesis in luffa roots decreased the drought tolerance in cucumber and luffa plants. Our study demonstrates that the roots of luffa have developed an enhanced ability to sense the changes in root-zone moisture and could eventually deliver modest level of ABA from roots to shoots that enhances water use efficiency under drought stress. Such a mechanism could be greatly exploited to benefit the agricultural production especially in arid and semi-arid areas. PMID:26832070

Can Adverse Effects of Acidity and Aluminum Toxicity Be Alleviated by Appropriate Rootstock Selection in Cucumber?

PubMed Central

Rouphael, Youssef; Rea, Elvira; Cardarelli, Mariateresa; Bitterlich, Michael; Schwarz, Dietmar; Colla, Giuseppe

2016-01-01

Low-pH and aluminum (Al) stresses are the major constraints that limit crop yield in acidic soils. Grafting vegetable elite cultivars onto appropriate rootstocks may represent an effective tool to improve crop tolerance to acidity and Al toxicity. Two greenhouse hydroponic experiments were performed to evaluate growth, yield, biomass production, chlorophyll index, electrolyte leakage, mineral composition, and assimilate partitioning in plant tissues of cucumber plants (Cucumis sativus L. “Ekron”) either non-grafted or grafted onto “P360” (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne; E/C) or figleaf gourd (Cucurbita ficifolia Bouché; E/F). Cucumber plants were cultured in pots and supplied with nutrient solutions having different pH and Al concentrations: pH 6, pH 3.5, pH 3.5 + 1.5 mM Al, and pH 3.5 + 3 mM Al (Experiment 1, 14 days) and pH 6, pH 3.5, and pH 3.5 + 0.75 mM Al (Experiment 2, 67 days). Significant depression in shoot and root biomass was observed in response to acidity and Al concentrations, with Al-stress being more phytotoxic than low pH treatment. Significant decrease in yield, shoot, and root biomass, leaf area, SPAD index, N, K, Ca, Mg, Mn, and B concentration in aerial parts (leaves and stems) in response to low pH with more detrimental effects at pH 3.5 + Al. Grafted E/C plants grown under low pH and Al had higher yield, shoot, and root biomass compared to E/F and non-grafted plants. This better crop performance of E/C plants in response to Al stress was related to (i) a reduced translocation of Al from roots to the shoot, (ii) a better shoot and root nutritional status in K, Ca, Mg, Mn, and Zn concentration, (iii) a higher chlorophyll synthesis, as well as (iv) the ability to maintain cell membrane stability and integrity (lower electrolyte leakage). Data provide insight into the role of grafting on Al stress tolerance in cucumber. PMID:27621740

Reactions of Grape Rootstocks to Pratylenchus vulnus and Meloidogyne spp.

PubMed

Chitambar, J J; Raski, D J

1984-04-01

Five grape rootstocks were inoculated with 0, 100, 1,000, and 10,000 Pratylenchus vulnus. Dogridge and Saltcreek supported low average total numbers of P. vulnus, 136-705/pot, at 12 months after inoculation. Growth of both rootstocks was not affected. Harmony, Couderc 1613, and Ganzin 1 supported high average total numbers, 6-856 times the inoculum levels. Numbers in Harmony continued to increase at all levels but reduced root weight only at the 10,000 level after 12 months. Numbers in Couderc 1613 decreased by 15-30% after 12 months, and root weight was reduced at the 10,000 level. In Ganzin 1, total nematode numbers diminished after 12 months but were still at high levels; growth reduction was proportional to numbers of nematodes added. Meloidogyne incognita, M. javanica, and M. arenaria produced galls and egg masses in Harmony and Couderc 1613 only at 36 C. Galling in Ganzin 1 increased with increasing temperature. Galls in Ganzin 1 at 18 C supported mature females after 90 days. Harmony was resistant to M. incognita in single and concomitant inoculations of P. vulnus and M. incognita. At 250 days after inoculation, total numbers of P. vulnus increased above the inoculum level and the 150-day values; increase was greatest in P. vulnus added singly. Neither nematode species affected growth of Harmony.

Comparative transcriptome profiling of chilling stress responsiveness in grafted watermelon seedlings.

PubMed

Xu, Jinhua; Zhang, Man; Liu, Guang; Yang, Xingping; Hou, Xilin

2016-12-01

Rootstock grafting may improve the resistance of watermelon plants to low temperatures. However, information regarding the molecular responses of rootstock grafted plants to chilling stress is limited. To elucidate the molecular mechanisms of chilling tolerance in grafted plants, the transcriptomic responses of grafted watermelon under chilling stress were analyzed using RNA-seq analysis. Sequencing data were used for digital gene expression (DGE) analysis to characterize the transcriptomic responses in grafted watermelon seedlings. A total of 702 differentially-expressed genes (DEGs) were found in rootstock grafted (RG) watermelon relative to self-grafted (SG) watermelon; among these genes, 522 genes were up-regulated and 180 were down-regulated. Additionally, 164 and 953 genes were found to specifically expressed in RG and SG seedlings under chilling stress, respectively. Functional annotations revealed that up-regulated DEGs are involved in protein processing, plant-pathogen interaction and the spliceosome, whereas down-regulated DEGs are associated with photosynthesis. Moreover, 13 DEGs were randomly selected for quantitative real time PCR (qRT-PCR) analysis. The expression profiles of these 13 DEGs were consistent with those detected by the DGE analysis, supporting the reliability of the DGE data. This work provides additional insight into the molecular basis of grafted watermelon responses to chilling stress. Copyright © 2016. Published by Elsevier Masson SAS.

Improved Salinity Tolerance in Carrizo Citrange Rootstock through Overexpression of Glyoxalase System Genes

PubMed Central

Alvarez-Gerding, Ximena; Cortés-Bullemore, Rowena; Medina, Consuelo; Romero-Romero, Jesús L.; Inostroza-Blancheteau, Claudio; Aquea, Felipe; Arce-Johnson, Patricio

2015-01-01

Citrus plants are widely cultivated around the world and, however, are one of the most salt stress sensitive crops. To improve salinity tolerance, transgenic Carrizo citrange rootstocks that overexpress glyoxalase I and glyoxalase II genes were obtained and their salt stress tolerance was evaluated. Molecular analysis showed high expression for both glyoxalase genes (BjGlyI and PgGlyII) in 5H03 and 5H04 lines. Under control conditions, transgenic and wild type plants presented normal morphology. In salinity treatments, the transgenic plants showed less yellowing, marginal burn in lower leaves and showed less than 40% of leaf damage compared with wild type plants. The transgenic plants showed a significant increase in the dry weight of shoot but there are no differences in the root and complete plant dry weight. In addition, a higher accumulation of chlorine is observed in the roots in transgenic line 5H03 but in shoot it was lower. Also, the wild type plant accumulated around 20% more chlorine in the shoot compared to roots. These results suggest that heterologous expression of glyoxalase system genes could enhance salt stress tolerance in Carrizo citrange rootstock and could be a good biotechnological approach to improve the abiotic stress tolerance in woody plant species. PMID:26236739

Cloning and expression analysis of the Ccrboh gene encoding respiratory burst oxidase in Citrullus colocynthis and grafting onto Citrullus lanatus (watermelon)

PubMed Central

Si, Ying; Dane, Fenny; Rashotte, Aaron; Kang, Kwonkyoo; Singh, Narendra K.

2010-01-01

A full-length drought-responsive gene Ccrboh, encoding the respiratory burst oxidase homologue (rboh), was cloned in Citrullus colocynthis, a very drought-tolerant cucurbit species. The robh protein, also named NADPH oxidase, is conserved in plants and animals, and functions in the production of reactive oxygen species (ROS). The Ccrboh gene accumulated in a tissue-specific pattern when C. colocynthis was treated with PEG, abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), or NaCl, while the homologous rboh gene did not show any change in C. lanatus var. lanatus, cultivated watermelon, during drought. Grafting experiments were conducted using C. colocynthis or C. lanatus as the rootstock or scion. Results showed that the rootstock significantly affects gene expression in the scion, and some signals might be transported from the root to the shoot. Ccrboh in C. colocynthis was found to function early during plant development, reaching high mRNA transcript levels 3 d after germination. The subcellular location of Ccrboh was investigated by transient expression of the 35S::Ccrboh::GFP fusion construct in protoplasts. The result confirmed that Ccrboh is a transmembrane protein. Our data suggest that Ccrboh might be functionally important during the acclimation of plants to stress and also in plant development. It holds great promise for improving drought tolerance of other cucurbit species. PMID:20181664

Cloning and expression analysis of the Ccrboh gene encoding respiratory burst oxidase in Citrullus colocynthis and grafting onto Citrullus lanatus (watermelon).

PubMed

Si, Ying; Dane, Fenny; Rashotte, Aaron; Kang, Kwonkyoo; Singh, Narendra K

2010-06-01

A full-length drought-responsive gene Ccrboh, encoding the respiratory burst oxidase homologue (rboh), was cloned in Citrullus colocynthis, a very drought-tolerant cucurbit species. The robh protein, also named NADPH oxidase, is conserved in plants and animals, and functions in the production of reactive oxygen species (ROS). The Ccrboh gene accumulated in a tissue-specific pattern when C. colocynthis was treated with PEG, abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), or NaCl, while the homologous rboh gene did not show any change in C. lanatus var. lanatus, cultivated watermelon, during drought. Grafting experiments were conducted using C. colocynthis or C. lanatus as the rootstock or scion. Results showed that the rootstock significantly affects gene expression in the scion, and some signals might be transported from the root to the shoot. Ccrboh in C. colocynthis was found to function early during plant development, reaching high mRNA transcript levels 3 d after germination. The subcellular location of Ccrboh was investigated by transient expression of the 35S::Ccrboh::GFP fusion construct in protoplasts. The result confirmed that Ccrboh is a transmembrane protein. Our data suggest that Ccrboh might be functionally important during the acclimation of plants to stress and also in plant development. It holds great promise for improving drought tolerance of other cucurbit species.

Effects of Rootstocks on Cryotolerance and Overwintering Survivorship of Genic Male Sterile Lines in Upland Cotton (Gossypium hirsutum L.)

PubMed Central

Zhang, Xin; Zhang, Zhiyong; Wang, Qinglian; Chen, Peng; Chen, Guoping; Zhou, Ruiyang

2013-01-01

Grafting desirable scion on stress-tolerant rootstocks provides an opportunity to improve the cryotolerance of scion. Genic male sterile (GMS) lines of plant could be used as sterile line and maintainer in breeding, and they have the conspicuous characteristics that the fertility of which is easy to regain but hard to maintain by sexual reproduction. In order to maintain the fertility of GMS cotton by means of its perennial growth on the basis of frostless winters in Nanning, Guangxi autonomous region, GMS line A4 was grafted onto 7 cryotolerant rootstocks (F118, F697, F098, F112, F113, P098 and P113), and the cryotolerance and the overwintering survivorship of scions were investigated. In consequence, when compared with control (self-grafted A4), the relative conductivity of the grafted plants in shoot bark was reduced (8.80%), the content of soluble sugar, soluble protein and free proline were higher, 25.00, 1.55, 3.46%, respectively; the overwintering survival rate and the height of regeneration bud under field condition of grafted plants were higher, 10.44, 15.75%, respectively; the order of the grafted plants based on the average subordinate function value of overwintering survivorship was A4/F113>A4/F118>A4/F098>A4/F697>A4/F112>A4/P098>A4/P113>A4/A4(CK); the correlation analyses indicated that the physiological parameters of cryotolerance could be used for forecasting the overwintering survivorship, and the relative conductivity could be chosen as the first physiological parameter for forecasting cryotolerance or overwintering survivorship. The results indicate that the cryotolerance and the overwintering survivorship of GMS cotton could be improved by grafting, and F113 appeared to be a valuable rootstock. PMID:23667634

[Effects of different rootstocks on the weak light tolerance ability of summer black grape based on 4 photo-response models].

PubMed

Han, Xiao; Wang, Hai Bo; Wang, Xiao di; Shi, Xiang Bin; Wang, Bao Liang; Zheng, Xiao Cui; Wang, Zhi Qiang; Liu, Feng Zhi

2017-10-01

The photo response curves of 11 rootstock-scion combinations including summer black/Beta, summer black/1103P, summer black/101-14, summer black/3309C, summer black/140Ru, summer black/5C, summer black/5BB, summer black/420A, summer black/SO4, summer black/Kangzhen No.1, summer black/Huapu No.1 were fitted by rectangular hyperbola mo-del, non-rectangular hyperbola model, modified rectangular hyperbola model and exponential model respectively, and the differences of imitative effects were analyzed by determination coefficiency, light compensation point, light saturation point, initial quantum efficiency, maximum photosynthetic rate and dark respiration rate. The result showed that the fit coefficients of all four models were above 0.98, and there was no obvious difference on the fitted values of light compensation point among the four models. The modified rectangular hyperbola model fitted best on light saturation point, apparent quantum yield, maximum photosynthetic rate and dark respiration rate, and had the minimum AIC value based on the akaike information criterion, therefore, the modified rectangular hyperbola model was the best one. The clustering analysis indicated that summer black/SO4 and summer black/420A combinations had low light compensation point, high apparent quantum yield and low dark respiration rate among 11 rootstock-scion combinations, suggesting that these two combinations could use weak light more efficiently due to their less respiratory consumption and higher weak light tolerance. The Topsis comparison method ranked summer black/SO4 and summer black/420A combinations as No. 1 and No. 2 respectively in weak light tolerance ability, which was consistent with cluster analysis. Consequently, summer black has the highest weak light tolerance in case grafted on 420A or SO4, which could be the most suitable rootstock-scion combinations for protected cultivation.

Need and prospects for using tracer techniques in fruit breeding

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

Zagaja, S.W.

1975-01-01

Compared with staple food crops and fodder crops, the commercial value of fruits depends more on their quality than on their productivity. Modified screening techniques are therefore required for fruit crop improvement. The following are areas of fruit crop improvement in which tracer techniques could be used to speed up the progress: assessment of rootstocks and particularly their effect on vigour of growth and productivity of the trees; assessment of mutants productivity; assessment of adaptability to various habitats of fruit tree cultivars and rootstocks; and juvenility studies on fruit trees, aimed at shortening the juvenile stage. On each of thesemore » subjects background information is provided and suggestions are made concerning the scope of research. (auth)« less

CO2 effects on the waterlogging response of 'Gisela 5' and 'Gisela 6' (Prunus cerasusxPrunus canescens) sweet cherry (Prunus avium) rootstocks.

PubMed

Pérez-Jiménez, Margarita; Hernández-Munuera, María; Piñero, M Carmen; López-Ortega, Gregorio; Del Amor, Francisco M

2017-06-01

Climate change is submitting countries of the Mediterranean arc to periods of drought alternating with heavy rain and waterlogging. Eventual floods along with the rising CO 2 in the atmosphere present an unpredictable scenario that affects crop survival. The effect of both stresses combined has been studied in sweet cherry plants. 'Gisela 5' and 'Gisela 6' were evaluated as rootstocks of the sweet cherry cultivar 'Burlat'. Plants were placed in a controlled-climate chamber for 7days, then they were submitted to waterlogging for another 7days and the response to this stress and the subsequent recovery were studied (7 more days). The experiment was carried out at 400μmolmol -1 CO 2 (ambient CO 2 ) and 800μmolmol -1 CO 2 , at 26°C, and plant water status and growth, net CO 2 assimilation, transpiration, stomatal conductance, water potential, chlorophyll fluorescence, relative water content, anions content, proline, lipid peroxidation, soluble sugars, and starch were measured. Differences in the response and in its intensity were detected in both rootstocks. Some parameters - such as photosynthesis, soluble sugars, starch, TBARS, and NO 3 - - varied depending on the CO 2 conditions and the waterlogging effect. Elevated CO 2 was able to increase photosynthesis and thereby help plants to overcome waterlogging. Copyright © 2017 Elsevier GmbH. All rights reserved.

The resistance of sour orange to Citrus tristeza virus is mediated by both the salicylic acid and RNA silencing defence pathways.

PubMed

Gómez-Muñoz, Neus; Velázquez, Karelia; Vives, María Carmen; Ruiz-Ruiz, Susana; Pina, José Antonio; Flores, Ricardo; Moreno, Pedro; Guerri, José

2017-12-01

Citrus tristeza virus (CTV) induces in the field the decline and death of citrus varieties grafted on sour orange (SO) rootstock, which has forced the use of alternative decline-tolerant rootstocks in affected countries, despite the highly desirable agronomic features of the SO rootstock. Declining citrus plants display phloem necrosis below the bud union. In addition, SO is minimally susceptible to CTV compared with other citrus varieties, suggesting partial resistance of SO to CTV. Here, by silencing different citrus genes with a Citrus leaf blotch virus-based vector, we have examined the implication of the RNA silencing and salicylic acid (SA) defence pathways in the resistance of SO to CTV. Silencing of the genes RDR1, NPR1 and DCL2/DCL4, associated with these defence pathways, enhanced virus spread and accumulation in SO plants in comparison with non-silenced controls, whereas silencing of the genes NPR3/NPR4, associated with the hypersensitive response, produced a slight decrease in CTV accumulation and reduced stunting of SO grafted on CTV-infected rough lemon plants. We also found that the CTV RNA silencing suppressors p20 and p23 also suppress the SA signalling defence, with the suppressor activity being higher in the most virulent isolates. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Colonization of citrus seed coats by 'Candidatus Liberibacter asiaticus': implications for seed transmission of the bacterium.

PubMed

Hilf, Mark E

2011-10-01

Huanglongbing is an economically damaging disease of citrus associated with infection by 'Candidatus Liberibacter asiaticus'. Transmission of the organism via infection of seeds has not been demonstrated but is a concern since some citrus varieties, particularly those used as rootstocks in commercial plantings are propagated from seed. We compared the incidence of detection of 'Ca. Liberibacter asiaticus' DNA in individual fruit peduncles, seed coats, seeds, and in germinated seedlings from 'Sanguenelli' sweet orange and 'Conners' grapefruit fruits sampled from infected trees. Using real-time quantitative PCR (qPCR) we detected pathogen DNA in nucleic acid extracts of 36 and 100% of peduncles from 'Sanguenelli' and from 'Conners' fruits, respectively. We also detected pathogen DNA in extracts of 37 and 98% of seed coats and in 1.6 and 4% of extracts from the corresponding seeds of 'Sanguenelli' and 'Conners', respectively. Small amounts of pathogen DNA were detected in 10% of 'Sanguenelli' seedlings grown in the greenhouse, but in none of 204 extracts from 'Conners' seedlings. Pathogen DNA was detected in 4.9% and in 89% of seed coats peeled from seeds of 'Sanguenelli' and 'Conners' which were germinated on agar, and in 5% of 'Sanguenelli' but in none of 164 'Conners' seedlings which grew from these seeds on agar. No pathogen DNA was detected in 'Ridge Pineapple' tissue at 3 months post-grafting onto 'Sanguenelli' seedlings, even when pathogen DNA had been detected initially in the 'Sanguenelli' seedling. Though the apparent colonization of 'Conners' seeds was more extensive and nearly uniform compared with 'Sanguenelli' seeds, no pathogen DNA was detected in 'Conners' seedlings grown from these seeds. For either variety, no association was established between the presence of pathogen DNA in fruit peduncles and seed coats and in seedlings.

Artificial Neural Network Genetic Algorithm As Powerful Tool to Predict and Optimize In vitro Proliferation Mineral Medium for G × N15 Rootstock

PubMed Central

Arab, Mohammad M.; Yadollahi, Abbas; Shojaeiyan, Abdolali; Ahmadi, Hamed

2016-01-01

One of the major obstacles to the micropropagation of Prunus rootstocks has, up until now, been the lack of a suitable tissue culture medium. Therefore, reformulation of culture media or modification of the mineral content might be a breakthrough to improve in vitro multiplication of G × N15 (garnem). We found artificial neural network in combination of genetic algorithm (ANN-GA) as a very precise and powerful modeling system for optimizing the culture medium, So that modeling the effects of MS mineral salts (NH4+, NO3-, PO42-, Ca2+, K+, SO42-, Mg2+, and Cl−) on in vitro multiplication parameters (the number of microshoots per explant, average length of microshoots, weight of calluses derived from the base of stem explants, and quality index of plantlets) of G × N15. Showed high R2 correlation values of 87, 91, 87, and 74 between observed and predicted values were found for these four growth parameters, respectively. According to the ANN-GA results, among the input variables, NH4+ and NO3- had the highest values of VSR in data set for the parameters studied. The ANN-GA showed that the best proliferation rate was obtained from medium containing (mM) 27.5 NO3-, 14 NH4+, 5 Ca2+, 25.9 K+, 0.7 Mg2+, 1.1 PO42-, 4.7 SO42-, and 0.96 Cl−. The performance of the medium optimized by ANN-GA, denoted as YAS (Yadollahi, Arab and Shojaeiyan), was compared to that of standard growth media for all Prunus rootstock, including the Murashige and Skoog (MS) medium, (specific media) EM, Quoirin and Lepoivre (QL) medium, and woody plant medium (WPM) Prunus. With respect to shoot length, shoot number per cultured explant and productivity (number of microshoots × length of microshoots), YAS was found to be superior to other media for in vitro multiplication of G × N15 rootstocks. In addition, our results indicated that by using ANN-GA, we were able to determine a suitable culture medium formulation to achieve the best in vitro productivity. PMID:27807436

Root-zone temperatures affect phenology of bud break, flower cluster development, shoot extension growth and gas exchange of 'Braeburn' (Malus domestica) apple trees.

PubMed

Greer, Dennis H; Wünsche, Jens N; Norling, Cara L; Wiggins, Harry N

2006-01-01

We investigated the effects of root-zone temperature on bud break, flowering, shoot growth and gas exchange of potted mature apple (Malus domestica (Borkh.)) trees with undisturbed roots. Soil respiration was also determined. Potted 'Braeburn' apple trees on M.9 rootstock were grown for 70 days in a constant day/night temperature regime (25/18 degrees C) and one of three constant root-zone temperatures (7, 15 and 25 degrees C). Both the proportion and timing of bud break were significantly enhanced as root-zone temperature increased. Rate of floral cluster opening was also markedly increased with increasing root-zone temperature. Shoot length increased but shoot girth growth declined as root-zone temperatures increased. Soil respiration and leaf photosynthesis generally increased as root-zone temperatures increased. Results indicate that apple trees growing in regions where root zone temperatures are < or = 15 degrees C have delayed bud break and up to 20% fewer clusters than apple trees exposed to root zone temperatures of > or = 15 degrees C. The effect of root-zone temperature on shoot performance may be mediated through the mobilization of root reserves, although the role of phytohormones cannot be discounted. Variation in leaf photosynthesis across the temperature treatments was inadequately explained by stomatal conductance. Given that root growth increases with increasing temperature, changes in sink activity induced by the root-zone temperature treatments provide a possible explanation for the non-stomatal effect on photosynthesis. Irrespective of underlying mechanisms, root-zone temperatures influence bud break and flowering in apple trees.

Configuration of watermelon fruit quality in response to rootstock-mediated harvest maturity and postharvest storage.

PubMed

Kyriacou, Marios C; Soteriou, Georgios A; Rouphael, Youssef; Siomos, Anastasios S; Gerasopoulos, Dimitrios

2016-05-01

The configuration of watermelon fruit quality was analysed in a multi-factorial approach accounting for the effects of grafting, harvest maturity and postharvest storage. Diploid, seeded, hybrid cv. Pegasus, cultivated as scion on interspecific hybrid squash rootstock TZ148 and as non-grafted control, was stored at 25 °C following sequential harvests from the onset of ripening to over-maturity. Delayed rootstock-mediated climax in pulp lycopene and chroma was observed, while both were heightened by postharvest storage when harvest preceded full maturity. Pulp firmness was increased by 46.5% on TZ148, while postharvest decrease in firmness was non-significant. Non-grafted fruits attained their peak in pulp carbohydrate content earlier during ripening. Monosaccharide content declined and sucrose content increased both preharvest and postharvest; overall sugar content declined by 4.3% during storage. Pulp acidity decreased steadily with ripening but was moderately increased by grafting. Citrulline content increased by 12.5% on TZ148; moreover, it climaxed with ripening and declined with storage only in grafted fruit. Grafting enhances pulp texture and bioactive composition. Potential suppression of sugar content as a result of grafting is minimized at full commercial maturity. Brief postharvest ambient storage enhances pulp lycopene and chroma, especially in early-picked fruit, notwithstanding the depletion of monosaccharides and citrulline and a limited deterioration of texture. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Etiology of three recent diseases of citrus in São Paulo State: sudden death, variegated chlorosis and huanglongbing.

PubMed

Bové, Joseph Marie; Ayres, Antonio Juliano

2007-01-01

The state of São Paulo (SSP) is the first sweet orange growing region in the world. Yet, the SSP citrus industry has been, and still is, under constant attack from various diseases. In the 1940s, tristeza-quick decline (T-QD) was responsible for the death of 9 million trees in SSP. The causal agent was a new virus, citrus tristeza virus (CTV). The virus was efficiently spread by aphid vectors, and killed most of the trees grafted on sour orange rootstock. Control of the disease resided in replacing sour orange by alternative rootstocks giving tolerant combinations with scions such as sweet orange. Because of its drought resistance, Rangpur lime became the favourite alternative rootstock, and, by 1995, 85% of the SSP sweet orange trees were grafted on this rootstock. Therefore, when in 1999, many trees grafted on Rangpur lime started to decline and suddenly died, the spectre of T-QD seemed to hang over SSP again. By 2003, the total number of dead or affected trees was estimated to be over one million. The new disease, citrus sudden death (CSD), resembles T-QD in several aspects. The two diseases have almost the same symptoms, they spread in time and space in a manner strikingly similar, and the pathological anatomy of the bark at the bud union is alike. Transmission of the CSD agent by graft-inoculation has been obtained with budwood inoculum taken not only on CSD-affected trees (grafted on Rangpur lime), but also on symptomless trees (grafted on Cleopatra mandarin) from the same citrus block. This result shows that symptomless trees on Cleopatra mandarin are tolerant to the CSD agent. Trees on rootstocks such as Sunki mandarin or Swingle citrumelo are also tolerant. Thus, in the CSD-affected region, control consists in replacing Rangpur lime with compatible rootstocks, or in approach-grafting compatible rootstock seedlings to the scions of trees on Rangpur lime (inarching). More than 5 million trees have been inarched in this way. A new disease of sweet orange, citrus variegated chlorosis (CVC), was observed in 1987 in the Triangulo Mineiro of Minas Gerais State and the northern and north-eastern parts of SSP. By 2000, the disease affected already 34% of the 200 million sweet orange trees in SSP. By 2005, the percentage had increased to 43%, and CVC was present in all citrus growing regions of Brazil. Electron microscopy showed that xylem-limited bacteria were present in all symptomatic sweet orange leaves and fruit tissues tested, but not in similar materials from healthy, symptomless trees. Bacteria were consistently cultured from twigs of CVC-affected sweet orange trees but not from twigs of healthy trees. Serological analyses showed the CVC bacterium to be a strain of Xylella fastidiosa. The disease could be reproduced and Koch's postulates fulfilled, by mechanically inoculating a pure culture of X. fastidiosa isolate 8.1.b into sweet orange seedlings. The genome of a CVC strain of X. fastidiosa was sequenced in SSP in the frame of a project supported by FAPESP and Fundecitrus. X. fastidiosa is the first plant pathogenic bacterium, the genome of which has been sequenced. Until recently, America was free of huanglongbing (HLB), but in March 2004 and August 2005, symptoms of the disease were recognized, respectively in the State of São Paulo (SSP) and in Florida, USA. HLB was known in China since 1870 and in South Africa since 1928. Because of its destructiveness and its rapid spread by efficient psyllid insect-vectors, HLB is probably the most serious citrus disease. HLB is caused by a phloem sieve tube-restricted Gram negative bacterium, not yet available in culture. In the 1990s, the bacterium was characterized by molecular techniques as a member of the alpha proteobacteria designated Candidatus Liberibacter africanus for the disease in Africa, and Candidatus Liberibacter asiaticus for HLB in Asia. In SSP, Ca. L. asiaticus is also present, but most of the trees are infected with a new species, Candidatus Liberibacter americanus.

Effects of Soil Pre-Treatment with Basamid® Granules, Brassica juncea, Raphanus sativus, and Tagetes patula on Bacterial and Fungal Communities at Two Apple Replant Disease Sites

PubMed Central

Yim, Bunlong; Nitt, Heike; Wrede, Andreas; Jacquiod, Samuel; Sørensen, Søren J.; Winkelmann, Traud; Smalla, Kornelia

2017-01-01

Nurseries producing apple and rose rootstock plants, apple orchards as well as rose production often experience replanting problems after several cultivations at the same site when a chemical soil disinfectant is not applied. The etiology of apple and rose replanting problems is most likely caused by soil-borne pathogen complex, defined as “replant disease (RD)”. Symptoms typical of RD are reduced shoot and root growth, a smaller leaf area, a significant decrease in plant biomass, yield and fruit quality and a shorter life span. In our previous study, we showed that RD symptoms were reduced when apple rootstock M106 were grown in RD soils treated either with the soil fumigant Basamid or after biofumigation by incorporating Brassica juncea or Raphanus sativus or by growing Tagetes under field conditions compared to untreated control soil. The present study aimed at identifying potential bacterial and fungal taxa that were affected by different soil treatments and linking bacterial and fungal responders to plant performance. Miseq® Illumina® sequencing of 16S rRNA gene fragments (bacteria) and ITS regions (fungi) amplified from total community DNA extracted from soil samples taken 4 weeks after treatments were performed. Soil properties and culture history of the two RD sites greatly influenced soil microbiomes. Several bacterial genera were identified that significantly increased in treated soils such as Arthrobacter (R. sativus, both sites), Curtobacterium (Basamid, both sites), Terrimonas (Basamid and R. sativus, site A) and Ferruginibacter (B. juncea, site K and R. sativus, site A) that were also significantly and positively correlated with growth of apple M106 plants. Only few fungal genera, such as Podospora, Monographella and Mucor, were significantly promoted in soils treated with B. juncea and R. sativus (both sites). The least pronounced changes were recorded for bacterial as well as fungal communities in the RD soils planted with Tagetes. The detection of bacterial and fungal genera that were significantly increased in relative abundance in response to the treatments and that were positively correlated with plant growth suggests that management of the soil microbial community could contribute to overcome the apple RD encountered at affected sites. PMID:28919882

Cloning and characterization of XiR1, a locus responsible for dagger nematode resistance in grape.

PubMed

Hwang, Chin-Feng; Xu, Kenong; Hu, Rong; Zhou, Rita; Riaz, Summaira; Walker, M Andrew

2010-08-01

The dagger nematode, Xiphinema index, feeds aggressively on grape roots and in the process, vectors grapevine fanleaf virus (GFLV) leading to the severe viral disease known as fanleaf degeneration. Resistance to X. index and GFLV has been the key objective of grape rootstock breeding programs. A previous study found that resistance to X. index derived from Vitis arizonica was largely controlled by a major quantitative trait locus, XiR1 (X. index Resistance 1), located on chromosome 19. The study presented here develops high-resolution genetic and physical maps in an effort to identify the XiR1 gene(s). The mapping was carried out with 1,375 genotypes in three populations derived from D8909-15, a resistant selection from a cross of V. rupestris A. de Serres (susceptible) x V. arizonica b42-26 (resistant). Resistance to X. index was evaluated on 99 informative recombinants that were identified by screening the three populations with two markers flanking the XiR1 locus. The high-resolution genetic map of XiR1 was primarily constructed with seven DNA markers developed in this study. Physical mapping of XiR1 was accomplished by screening three bacterial artificial chromosome (BAC) libraries constructed from D8909-15, V. vinifera Cabernet Sauvignon and V. arizonica b42-26. A total of 32 BAC clones were identified and the XiR1 locus was delineated within a 115 kb region. Sequence analysis of three BAC clones identified putative nucleotide binding/leucine-rich repeat (NB-LRR) genes. This is the first report of a closely linked major gene locus responsible for ectoparasitic nematode resistance. The markers developed from this study are being used to expedite the breeding of resistant grape rootstocks.

Cloning and characterization of XiR1, a locus responsible for dagger nematode resistance in grape

PubMed Central

Hwang, Chin-Feng; Xu, Kenong; Hu, Rong; Zhou, Rita; Riaz, Summaira

2010-01-01

The dagger nematode, Xiphinemaindex, feeds aggressively on grape roots and in the process, vectors grapevine fanleaf virus (GFLV) leading to the severe viral disease known as fanleaf degeneration. Resistance to X. index and GFLV has been the key objective of grape rootstock breeding programs. A previous study found that resistance to X. index derived from Vitis arizonica was largely controlled by a major quantitative trait locus, XiR1 (X. index Resistance 1), located on chromosome 19. The study presented here develops high-resolution genetic and physical maps in an effort to identify the XiR1 gene(s). The mapping was carried out with 1,375 genotypes in three populations derived from D8909-15, a resistant selection from a cross of V. rupestris A. de Serres (susceptible) × V. arizonica b42-26 (resistant). Resistance to X. index was evaluated on 99 informative recombinants that were identified by screening the three populations with two markers flanking the XiR1 locus. The high-resolution genetic map of XiR1 was primarily constructed with seven DNA markers developed in this study. Physical mapping of XiR1 was accomplished by screening three bacterial artificial chromosome (BAC) libraries constructed from D8909-15, V. vinifera Cabernet Sauvignon and V. arizonica b42-26. A total of 32 BAC clones were identified and the XiR1 locus was delineated within a 115 kb region. Sequence analysis of three BAC clones identified putative nucleotide binding/leucine-rich repeat (NB-LRR) genes. This is the first report of a closely linked major gene locus responsible for ectoparasitic nematode resistance. The markers developed from this study are being used to expedite the breeding of resistant grape rootstocks. PMID:20490447

Influence of Pre- and Postharvest Summer Pruning on the Growth, Yield, Fruit Quality, and Carbohydrate Content of Early Season Peach Cultivars

PubMed Central

Ikinci, Ali

2014-01-01

Winter and summer pruning are widely applied processes in all fruit trees, including in peach orchard management. This study was conducted to determine the effects of summer prunings (SP), as compared to winter pruning (WP), on shoot length, shoot diameter, trunk cross sectional area (TCSA) increment, fruit yield, fruit quality, and carbohydrate content of two early ripening peach cultivars (“Early Red” and “Maycrest”) of six years of age, grown in semiarid climate conditions, in 2008 to 2010. The trees were grafted on GF 677 rootstocks, trained with a central leader system, and spaced 5 × 5 m apart. The SP carried out after harvesting in July and August decreased the shoot length significantly; however, it increased its diameter. Compared to 2009, this effect was more marked in year 2010. In general, control and winter pruned trees of both cultivars had the highest TCSA increment and yield efficiency. The SP increased the average fruit weight and soluble solids contents (SSC) more than both control and WP. The titratable acidity showed no consistent response to pruning time. The carbohydrate accumulation in shoot was higher in WP and in control than in SP trees. SP significantly affected carbohydrate accumulation; postharvest pruning showed higher carbohydrate content than preharvest pruning. PMID:24737954

Morphological observation, RNA-Seq quantification, and expression profiling: novel insight into grafting-responsive carotenoid biosynthesis in watermelon grafted onto pumpkin rootstock.

PubMed

Liu, Guang; Yang, Xingping; Xu, Jinhua; Zhang, Man; Hou, Qian; Zhu, Lingli; Huang, Ying; Xiong, Aisheng

2017-03-01

Watermelon is an important and economical horticultural crop in China, where ~20% of the plants are grafted. The development of grafted watermelon fruit involves a diverse range of gene interactions that results in dynamic changes in fruit. However, the molecular mechanisms underlying grafting-induced fruit quality change are unclear. In the present study, we measured the lycopene content by high-performance liquid chromatography and used RNA-Seq (quantification) to perform a genome-wide transcript analysis of fruits from watermelon grafted onto pumpkin rootstock (pumpkin-grafted watermelon, PGW), self-grafted watermelon (SGW), and non-grafted watermelon (NGW). The results showed variation in the lycopene content in the flesh of PGW fruits, first increasing and then decreasing in the four stages, which was different from the trend in the flesh of NGW and SGW fruits. The transcriptome profiling data provided new information on the grafting-induced gene regulation of lycopene biosynthesis during fruit growth and development. The expression levels of 33 genes from 8 gene families (GGPS, PSY, PDS, ZDS, CRTISO, LCYb, LCYe, and CHY) related to lycopene biosynthesis, which play critical roles in fruit coloration and contribute significantly to fruit phytonutrient values, were monitored during the four periods of fruit development in watermelon. Compared with those of NGW and SGW, 14 genes were differentially expressed in PGW during fruit development, suggesting that these genes possibly help to mediate lycopene biosynthesis in grafted watermelon fruit. Our work provides some novel insights into grafting-responsive carotenoid metabolism and its potential roles during PGW fruit development and ripening. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Genetic linkage map of the interspecific grape rootstock cross Ramsey (Vitis champinii) x Riparia Gloire (Vitis riparia).

PubMed

Lowe, K M; Walker, M A

2006-05-01

The first genetic linkage map of grape derived from rootstock parents was constructed using 188 progeny from a cross of Ramsey (Vitis champinii) x Riparia Gloire (V. riparia). Of 354 simple sequence repeat markers tested, 205 were polymorphic for at least one parent, and 57.6% were fully informative. Maps of Ramsey, Riparia Gloire, and the F1 population were created using JoinMap software, following a pseudotestcross strategy. The set of 205 SSRs allowed for the identification of all 19 Vitis linkage groups (2n=38), with a total combined map length of 1,304.7 cM, averaging 6.8 cM between markers. The maternal map consists of 172 markers aligned into 19 linkage groups (1,244.9 cM) while 126 markers on the paternal map cover 18 linkage groups (1,095.5 cM). The expected genome coverage is over 92%. Segregation distortion occurred in the Ramsey, Riparia Gloire, and consensus maps for 10, 13, and 16% of the markers, respectively. These distorted markers clustered primarily on the linkage groups 3, 5, 14 and 17. No genome-wide difference in recombination rate was observed between Ramsey and Riparia Gloire based on 315 common marker intervals. Fifty-four new Vitis-EST-derived SSR markers were mapped, and were distributed evenly across the genome on 16 of the 19 linkage groups. These dense linkage maps of two phenotypically diverse North American Vitis species are valuable tools for studying the genetics of many rootstock traits including nematode resistance, lime and salt tolerance, and ability to induce vigor.

Significant and unique changes in phosphorylation levels of four phosphoproteins in two apple rootstock genotypes under drought stress.

PubMed

Ren, Jing; Mao, Juan; Zuo, Cunwu; Calderón-Urrea, Alejandro; Dawuda, Mohammed Mujitaba; Zhao, Xin; Li, Xinwen; Chen, Baihong

2017-12-01

Drought stress is a major problem around the world and there is still little molecular mechanism about how fruit crops deal with moderate drought stress. Here, the physiological and phosphoproteomic responses of drought-sensitive genotype (M26) and drought-tolerant genotype (MBB) under moderate drought stress were investigated. Our results of the physiology analysis indicated that the MBB genotype could produce more osmosis-regulating substances. Furthermore, phosphoproteins from leaves of both genotypes under moderate drought stress were analyzed using the isobaric tags for relative and absolute quantification technology. A total of 595 unique phosphopeptides, 682 phosphorylated sites, and 446 phosphoproteins were quantitatively analyzed in the two genotypes. Five and thirty-five phosphoproteins with the phosphorylation levels significantly changed (PLSC) were identified in M26 and MBB, respectively. Among these, four PLSC phosphoproteins were common to both genotypes, perhaps indicating a partial overlap of the mechanisms to moderate drought stress. Gene ontology analyses revealed that the PLSC phosphoproteins represent a unique combination of metabolism, transcription, translation, and protein processing, suggesting that the response in apple to moderate drought stress encompasses a new and unique homeostasis of major cellular processes. The basic trend was an increase in protein and organic molecules abundance related to drought. These increases were higher in MBB than in M26. Our study is the first to address the phosphoproteome of apple rootstocks in response to moderate drought stress, and provide insights into the molecular regulation mechanisms of apple rootstock under moderate drought stress.

Artificial Neural Network Genetic Algorithm As Powerful Tool to Predict and Optimize In vitro Proliferation Mineral Medium for G × N15 Rootstock.

PubMed

Arab, Mohammad M; Yadollahi, Abbas; Shojaeiyan, Abdolali; Ahmadi, Hamed

2016-01-01

One of the major obstacles to the micropropagation of Prunus rootstocks has, up until now, been the lack of a suitable tissue culture medium. Therefore, reformulation of culture media or modification of the mineral content might be a breakthrough to improve in vitro multiplication of G × N15 (garnem). We found artificial neural network in combination of genetic algorithm (ANN-GA) as a very precise and powerful modeling system for optimizing the culture medium, So that modeling the effects of MS mineral salts ([Formula: see text], [Formula: see text], [Formula: see text], Ca 2+ , K + , [Formula: see text], Mg 2+ , and Cl - ) on in vitro multiplication parameters (the number of microshoots per explant, average length of microshoots, weight of calluses derived from the base of stem explants, and quality index of plantlets) of G × N15. Showed high R 2 correlation values of 87, 91, 87, and 74 between observed and predicted values were found for these four growth parameters, respectively. According to the ANN-GA results, among the input variables, [Formula: see text] and [Formula: see text] had the highest values of VSR in data set for the parameters studied. The ANN-GA showed that the best proliferation rate was obtained from medium containing (mM) 27.5 [Formula: see text], 14 [Formula: see text], 5 Ca 2+ , 25.9 K + , 0.7 Mg 2+ , 1.1 [Formula: see text], 4.7 [Formula: see text], and 0.96 Cl - . The performance of the medium optimized by ANN-GA, denoted as YAS (Yadollahi, Arab and Shojaeiyan), was compared to that of standard growth media for all Prunus rootstock, including the Murashige and Skoog (MS) medium, (specific media) EM, Quoirin and Lepoivre (QL) medium, and woody plant medium (WPM) Prunus . With respect to shoot length, shoot number per cultured explant and productivity (number of microshoots × length of microshoots), YAS was found to be superior to other media for in vitro multiplication of G × N15 rootstocks. In addition, our results indicated that by using ANN-GA, we were able to determine a suitable culture medium formulation to achieve the best in vitro productivity.

Recent advances in the cryopreservation of shoot-derived germplasm of economically important fruit trees of Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis.

PubMed

Benelli, Carla; De Carlo, Anna; Engelmann, Florent

2013-01-01

This paper presents the advances made over the last decade in cryopreservation of economically important vegetatively propagated fruit trees. Cryopreservation protocols have been established using both dormant buds sampled on field-grown plants and shoot tips sampled on in vitro plantlets. In the case of dormant buds, scions are partially dehydrated by storage at -5 °C, and then cooled slowly to -30 °C using low cooling rates (c.a. 1 °C/h) before immersion in liquid nitrogen. After slow rewarming and rehydration of samples, regrowth takes place either through grafting of buds on rootstocks or excision of apices and inoculation in vitro. In the case of shoot tips of in vitro plantlets, the cryopreservation techniques employed are the following: controlled rate cooling procedures involving slow prefreezing followed by immersion in liquid nitrogen or vitrification-based procedures including encapsulation-dehydration, vitrification, encapsulation-vitrification and droplet-vitrification. The current status of cryopreservation for a series of fruit tree species including Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis is presented. Routine application of cryopreservation for long-term germplasm storage in genebanks is currently limited to apple and pear, for which large cryopreserved collections have been established at NCGRP, Fort Collins (USA), using dormant buds and in vitro shoot tips, respectively. However, there are a growing number of examples of pilot scale testing experiments under way for different species in various countries. Progress in the further development and application of cryopreservation techniques will be made through a better understanding of the mechanisms involved in the induction of tolerance to dehydration and cryopreservation in frozen explants. Copyright © 2012 Elsevier Inc. All rights reserved.

Expression of Bacillus thuringiensis cytolytic toxin (Cyt2Ca1) in citrus roots to control Diaprepes abbreviatus larvae.

PubMed

Mahmoud, Sulley Ben; Ramos, John E; Shatters, Robert G; Hall, David G; Lapointe, Stephen L; Niedz, Randall P; Rougé, Pierre; Cave, Ronald D; Borovsky, Dov

2017-03-01

Diaprepes abbreviatus (L.) is an important pest of citrus in the USA. Currently, no effective management strategies of D. abbreviatus exist in citriculture, and new methods of control are desperately sought. To protect citrus against D. abbreviatus a transgenic citrus rootstock expressing Bacillus thuringiensis Cyt2Ca1, an insect toxin protein, was developed using Agrobacterium-mediated transformation of 'Carrizo' citrange [Citrus sinensis (L) Osbeck Poncirus trifoliate (L) Raf]. The transgenic citrus root stock expressed the cytolytic toxin Cyt2Ca1 constitutively under the control of a 35S promoter in the transgenic Carrizo citrange trifoliate hybrid including the roots that are the food source of larval D. abbreviatus. The engineered citrus was screened by Western blot and RT-qPCR analyses for cyt2Ca1 and positive citrus identified. Citrus trees expressing different levels of cyt2Ca1 transcripts were identified (Groups A-C). High expression of the toxin in the leaves (10 9 transcripts/ng RNA), however, retarded plant growth. The transgenic plants were grown in pots and the roots exposed to 3week old D. abbreviatus larvae using no-choice plant bioassays. Three cyt2Ca1 transgenic plants were identified that sustained less root damage belonging to Group B and C. One plant caused death to 43% of the larvae that fed on its roots expressed 8×10 6 cyt2Ca1 transcripts/ng RNA. These results show, for the first time, that Cyt2Ca1 expressed in moderate amounts by the roots of citrus does not retard citrus growth and can protect it from larval D. abbreviatus. Published by Elsevier Inc.

Effect of various factors on shoot regeneration from citrus epicotyl explants

USDA-ARS?s Scientific Manuscript database

The effect of various treatments on shoot organogenesis from seedling epicotyl explants from various scion and rootstock polyembryonic citrus types was determined. Treatments included water source, gelling agent, explant insertion, seed size, light intensity, malachite green, nonionic surfactants, a...

Grafting for Management of Root-Knot Nematodes in Watermelon

USDA-ARS?s Scientific Manuscript database

Five wild watermelon (Citrullus lanatus var. citroides) germplasm lines, four bottlegourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata x C. maxima) hybrid, and one commercial wild watermelon (C. lanatus spp.) cultivar were evaluated as rootstocks for watermelon in a field infested...

Grafting for Management of Southern Root-knot Nematode, Meloidogyne Incognita, in Watermelon

USDA-ARS?s Scientific Manuscript database

Four bottlegourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata x C. maxima) hybrid, four wild watermelon (Citrullus lanatus var. citroides) germplasm lines, and one commercial wild watermelon (C. lanatus var. citroides) cultivar were evaluated as rootstocks for cultivated watermelo...

Novel Prunus rootstock somaclonal variants with divergent ability to tolerate waterlogging.

PubMed

Pistelli, Laura; Iacona, Calogero; Miano, Dario; Cirilli, Marco; Colao, Maria Chiara; Mensuali-Sodi, Anna; Muleo, Rosario

2012-03-01

Plants require access to free water for nutrient uptake, but excess water surrounding the roots can be injurious or even lethal because it blocks the transfer of free oxygen between the soil and the atmosphere. Genetic improvement efforts in this study were focused on the increased tolerance in roots to waterlogging. Among a pool of clones generated in vitro from leaf explants of rootstock Mr.S.2/5 of Prunus cerasifera L., the S.4 clone was flood tolerant whereas the S.1 clone was sensitive. The S.4 clone formed adventitious roots on exposure to flooding. Moreover, the chlorophyll content and mitochondrial activity in the leaf and root, soluble sugar content, alcohol dehydrogenase activity and ethylene content were different between the clones. The sorbitol transporter gene (SOT1) was up-regulated during hypoxia, the alcohol dehydrogenase genes (ADH1 and ADH3) were up-regulated in the leaves and down-regulated in the roots of the S.4 clone during hypoxia, and the 1-aminocyclopropane-1-oxidase gene (ACO1) was up-regulated in the leaves and roots of the S.4 clone during hypoxia and down-regulated in the wild-type roots. In addition, in the S.4 root, hypoxia induced significant down-regulation of a glycosyltransferase-like gene (GTL), which has a yet-undefined role. Although the relevant variation in the S.4 genome has yet to be determined, genetic alteration clearly conferred a flooding-tolerant phenotype. The isolation of novel somaclonals with the same genomic background but with divergent tolerance to flooding may offer new insights in the elucidation of the genetic machinery of resistance to flooding and aid in the selection of new Prunus rootstocks to be used in various adverse environments.

Involvement of ascorbate peroxidase and heat shock proteins on citrus tolerance to combined conditions of drought and high temperatures.

PubMed

Balfagón, Damián; Zandalinas, Sara I; Baliño, Pablo; Muriach, María; Gómez-Cadenas, Aurelio

2018-06-01

Usually several environmental stresses occur in nature simultaneously causing a unique plant response. However, most of the studies until now have focused in individually-applied abiotic stress conditions. Carrizo citrange (Poncirus trifoliata L. Raf. X Citrus sinensis L. Osb.) and Cleopatra mandarin (Citrus reshni Hort. ex Tan.) are two citrus rootstocks with contrasting tolerance to drought and heat stress and have been used in this work as a model for the study of plant tolerance to the combination of drought and high temperatures. According to our results, leaf integrity and photosynthetic machinery are less affected in Carrizo than in Cleopatra under combined conditions of drought and heat stress. The pattern of accumulation of three proteins (APX, HSP101 and HSP17.6) involved in abiotic stress tolerance shows that they do not accumulate under water stress conditions individually applied. However, contents of APX and HSP101 are higher in Carrizo than in Cleopatra under stress combination whereas HSP17.6 has a similar behavior in both types of plants. This, together with a better stomatal control and a higher APX activity of Carrizo, contributes to the higher tolerance of Carrizo plants to the combination of stresses and point to it as a better rootstock than Cleopatra (traditionally used in areas with scare water supplies) under the predictable future climatic conditions with frequent periods of drought combined with high temperatures. This work also provides the basis for testing the tolerance of different citrus varieties grafted on these rootstocks and growing under different field conditions. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Biochemical changes in grape rootstocks resulted from humic acid treatments in relation to nematode infection.

PubMed

Kesba, Hosny H; El-Beltagi, Hossam S

2012-04-01

To investigate the effect of humic acid on nematode infected, resistant and susceptible grapes in relation to lipid peroxidation and antioxidant mechanisms on selected biochemical parameters known as proactive substances. The grape rootstocks, superior, superior/freedom and freedom were reacted differently to Meloidogyne incognita and Rotylenchulus reniformis according to rootstock progenitor. Two weeks after inoculation, two commercial products of humic acid were applied at the rate of (2, 4 mL or grams/plant) as soil drench. After 4 months, nematode soil populations were extracted and counted. A subsample of roots from each plant was stained and gall numbers, embedded stages per root were calculated, final population, nematode build up (Pf/Pi), average of eggs/eggmass were estimated. Subsamples of fresh root of each treatment were chemically analyzed. Freedom reduced significantly the nematode criteria and build up. Humic acid granules appeared to be more suppressive to nematode build up on superior and the higher dose on superior/freedom than liquid treatments. On freedom, all treatments reduced significantly the nematode build up regardless to the material nature. The higher dose was more effective than the lower one. As a result of humic acid applications, the malondialdehyde (MDA) and H2O2 contents were significantly reduced after humic acid treatments while the antioxidant compounds glutathione (GSH), ascorbic acid (ASA) and total phenol contents were significantly increased when compared with check. Antioxidant defense enzymes ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and polyphenol oxidase (PPO)showed significant increase in their specific activities in treated plants compared with nematode treated check. Humic acid treatments improve the yield of grape by increasing the contents of antioxidant compounds and the specific activities of antioxidant enzymes.

Systemic resistance in citrus to Tetranychus urticae induced by conspecifics is transmitted by grafting and mediated by mobile amino acids.

PubMed

Agut, Blas; Gamir, Jordi; Jaques, Josep A; Flors, Victor

2016-10-01

Recent research suggests that systemic signalling and communication between roots and leaves plays an important role in plant defence against herbivores. In the present study, we show that the oviposition of the two-spotted spider mite Tetranychus urticae in the systemic leaves of citrus rootstock Citrus aurantium (sour orange) was reduced by 50% when a lower leaf was previously infested with conspecifics. Metabolomic and gene expression analysis of the root efflux revealed a strong accumulation of glutamic acid (Glu) that triggered the expression of the citrus putative glutamate receptor (GRL) in the shoots. Additionally, uninfested sour orange systemic leaves showed increased expression of glutamate receptors and higher amounts of jasmonic acid (JA) and 12-oxo-phytodienoic acid in plants that were previously infested. Glu perception in the shoots induced the JA pathway, which primed LOX-2 gene expression when citrus plants were exposed to a second infestation. The spider mite-susceptible citrus rootstock Cleopatra mandarin (C. unshiu) also expressed systemic resistance, although the resistance was less effective than the resistance in sour orange. Surprisingly, the mobile signal in Cleopatra mandarin was not Glu, which suggests a strong genotype-dependency for systemic signalling in citrus. When the cultivar Clemenules (C. clementina) was grafted onto sour orange, there was a reduction in symptomatic leaves and T. urticae populations compared to the same cultivar grafted onto Cleopatra mandarin. Thus, systemic resistance is transmitted from the roots to the shoots in citrus and is dependent on rootstock resistance. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Biochemical changes in grape rootstocks resulted from humic acid treatments in relation to nematode infection

PubMed Central

Kesba, Hosny H; El-Beltagi, Hossam S

2012-01-01

Objective To investigate the effect of humic acid on nematode infected, resistant and susceptible grapes in relation to lipid peroxidation and antioxidant mechanisms on selected biochemical parameters known as proactive substances. Methods The grape rootstocks, superior, superior/freedom and freedom were reacted differently to Meloidogyne incognita and Rotylenchulus reniformis according to rootstock progenitor. Two weeks after inoculation, two commercial products of humic acid were applied at the rate of (2, 4 mL or grams/plant) as soil drench. After 4 months, nematode soil populations were extracted and counted. A subsample of roots from each plant was stained and gall numbers, embedded stages per root were calculated, final population, nematode build up (Pf/Pi), average of eggs/eggmass were estimated. Subsamples of fresh root of each treatment were chemically analyzed. Results Freedom reduced significantly the nematode criteria and build up. Humic acid granules appeared to be more suppressive to nematode build up on superior and the higher dose on superior/freedom than liquid treatments. On freedom, all treatments reduced significantly the nematode build up regardless to the material nature. The higher dose was more effective than the lower one. As a result of humic acid applications, the malondialdehyde (MDA) and H2O2 contents were significantly reduced after humic acid treatments while the antioxidant compounds glutathione (GSH), ascorbic acid (ASA) and total phenol contents were significantly increased when compared with check. Antioxidant defense enzymes ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and polyphenol oxidase (PPO)showed significant increase in their specific activities in treated plants compared with nematode treated check. Conclusions Humic acid treatments improve the yield of grape by increasing the contents of antioxidant compounds and the specific activities of antioxidant enzymes. PMID:23569915

Cisgenic apple trees; development, characterization, and performance

PubMed Central

Krens, Frans A.; Schaart, Jan G.; van der Burgh, Aranka M.; Tinnenbroek-Capel, Iris E. M.; Groenwold, Remmelt; Kodde, Linda P.; Broggini, Giovanni A. L.; Gessler, Cesare; Schouten, Henk J.

2015-01-01

Two methods were developed for the generation of cisgenic apples. Both have been successfully applied producing trees. The first method avoids the use of any foreign selectable marker genes; only the gene-of-interest is integrated between the T-DNA border sequences. The second method makes use of recombinase-based marker excision. For the first method we used the MdMYB10 gene from a red-fleshed apple coding for a transcription factor involved in regulating anthocyanin biosynthesis. Red plantlets were obtained and presence of the cisgene was confirmed. Plantlets were grafted and grown in a greenhouse. After 3 years, the first flowers appeared, showing red petals. Pollination led to production of red-fleshed cisgenic apples. The second method used the pM(arker)F(ree) vector system, introducing the scab resistance gene Rvi6, derived from apple. Agrobacterium-mediated transformation, followed by selection on kanamycin, produced genetically modified apple lines. Next, leaves from in vitro material were treated to activate the recombinase leading to excision of selection genes. Subsequently, the leaf explants were subjected to negative selection for marker-free plantlets by inducing regeneration on medium containing 5-fluorocytosine. After verification of the marker-free nature, the obtained plants were grafted onto rootstocks. Young trees from four cisgenic lines and one intragenic line, all containing Rvi6, were planted in an orchard. Appropriate controls were incorporated in this trial. We scored scab incidence for three consecutive years on leaves after inoculations with Rvi6-avirulent strains. One cisgenic line and the intragenic line performed as well as the resistant control. In 2014 trees started to overcome their juvenile character and formed flowers and fruits. The first results of scoring scab symptoms on apple fruits were obtained. Apple fruits from susceptible controls showed scab symptoms, while fruits from cisgenic and intragenic lines were free of scab. PMID:25964793

Precocious flowering in trees: the FLOWERING LOCUS T gene as a research and breeding tool in Populus.

PubMed

Zhang, Huanling; Harry, David E; Ma, Cathleen; Yuceer, Cetin; Hsu, Chuan-Yu; Vikram, Vikas; Shevchenko, Olga; Etherington, Elizabeth; Strauss, Steven H

2010-06-01

Expression of FLOWERING LOCUS T (FT) and its homologues has been shown to accelerate the onset of flowering in a number of plant species, including poplar (Populus spp.). The application of FT should be of particular use in forest trees, as it could greatly accelerate and enable new kinds of breeding and research. Recent evidence showing the extent to which FT is effective in promoting flowering in trees is discussed, and its effectiveness in poplar is reported. Results using one FT gene from Arabidopsis and two from poplar, all driven by a heat-inducible promoter, transformed into two poplar genotypes are also described. Substantial variation in flowering response was observed depending on the FT gene and genetic background. Heat-induced plants shorter than 30 cm failed to flower as well as taller plants. Plants exposed to daily heat treatments lasting 3 weeks tended to produce fewer abnormal flowers than those in heat treatments of shorter durations; increasing the inductive temperature from 37 degrees C to 40 degrees C produced similar benefits. Using optimal induction conditions, approximately 90% of transgenic plants could be induced to flower. When induced FT rootstocks were grafted with scions that lacked FT, flowering was only observed in rootstocks. The results suggest that a considerable amount of species- or genotype-specific adaptation will be required to develop FT into a reliable means for shortening the generation cycle for breeding in poplar.

Biological Indexing of Graft Transmissible Diseases of Citrus

USDA-ARS?s Scientific Manuscript database

Biological indexing for the detection of graft transmissible diseases of citrus is essential for maintaining a citrus certification program. Many of the graft transmissible diseases of citrus are harbored as latent infections in the scions, but when propagated on a susceptible rootstock that allow...

Utility of Grafting for Managing Southern Root-knot Nematode, Meloidogyne Incognita, in Watermelon

USDA-ARS?s Scientific Manuscript database

Four bottlegourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata x C. maxima) hybrid, four wild watermelon (Citrullus lanatus var. citroides) germplasm lines, and one commercial wild watermelon (C. lanatus var. citroides) cultivar were evaluated as rootstocks for cultivated watermelo...

Bell pepper rootstock response to Phytophthora capsici under salinity stress

USDA-ARS?s Scientific Manuscript database

Vegetable grafting is currently used as an eco-friendly technology to increase crop productivity and overcome several biotic and abiotic stress conditions that affect Cucurbitaceae and Solanaceae vegetable crops. In recent years, researchers with breeding programs and seed companies have selected ro...

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 can be inoculated in a controlled manner with CBSV and UCBSV, either singly or together. Disease symptoms develop rapidly, allowing better studies of interactions between these viral pathogens, their movement within shoot and root systems, and how they induce their destructive disease symptoms.

Genome-wide identification and characterization of WRKY transcriptional factor family in apple and analysis of their responses to waterlogging and drought stress.

PubMed

Meng, Dong; Li, Yuanyuan; Bai, Yang; Li, Mingjun; Cheng, Lailiang

2016-06-01

As one of the largest transcriptional factor families in plants, WRKY genes play significant roles in various biotic and abiotic stress responses. Although the WRKY gene family has been characterized in a few plant species, the details remain largely unknown in the apple (Malus domestica Borkh.). In this study, we identified a total of 127 MdWRKYs from the apple genome, which were divided into four subgroups according to the WRKY domains and zinc finger motif. Most of them were mapped onto the apple's 17 chromosomes and were expressed in more than one tissue, including shoot tips, mature leaves, fruit and apple calli. We then contrasted WRKY expression patterns between calli grown in solid medium (control) and liquid medium (representing waterlogging stress) and found that 34 WRKY genes were differentially expressed between the two growing conditions. Finally, we determined the expression patterns of 10 selected WRKY genes in an apple rootstock, G41, in response to waterlogging and drought stress, which identified candidate genes involved in responses to water stress for functional analysis. Our data provide interesting candidate MdWRKYs for future functional analysis and demonstrate that apple callus is a useful system for characterizing gene expression and function in apple. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Grafting as a Production System Component for Nematode Management in Florida Vegetables

USDA-ARS?s Scientific Manuscript database

Trials in Florida evaluated grafting for control of root-knot nematode (Meloidogyne incognita) in tomato, cantaloupe, and pepper. Pepper rootstocks assessed included ‘Charleston Hot’, ‘Carolina Wonder’, ‘Charleston Belle’, ‘Mississippi Nemaheart’, and ‘Carolina Cayenne’, which were resistant to gall...

Identification of grape cultivars and rootstocks with resistance to vine mealybug

USDA-ARS?s Scientific Manuscript database

Vine mealybug, an insect pest capable of causing direct and indirect damage to grape vineyards, costs California growers millions of dollars annually. Insecticide sprays used to manage the pest provide inconsistent results, and sustainable methods of control are needed. A previous study identified a...

In vitro seed germination and rootstock establishing for micrografting of Theobroma cacao L

USDA-ARS?s Scientific Manuscript database

Micrografting has been successfully implemented in several plant species of Acacia, Citrus, Eucalyptus, Havea, Malus, Olea, Opuntia, Prunus and other genera. This technique is employed for plant rejuvenation, true-to-type propagation, genetic improvement, recovery of virus-free plants, testing of po...

Evaluation of wild walnut Juglans spp. for resistance to crown gall disease

USDA-ARS?s Scientific Manuscript database

Crown gall (CG) disease of walnut is caused by the ubiquitous soil-borne bacterium, Agrobacterium tumefaciens. The most widely used rootstock Paradox, an interspecific hybrid between Juglans hindsii and Juglans regia, is typically highly susceptible to A. tumefaciens. Identification of a durable sou...

Impact of biological amendments on Agrobacterium tumefaciens soil survival

USDA-ARS?s Scientific Manuscript database

Paradox, the primary walnut rootstock used in California, is susceptible to Agrobacterium tumefaciens, which causes crown gall. While A. tumefaciens is susceptible to commonly used fumigants such as methyl bromide (MeBr) and Telone-C35 (1,3-dichloropropene and chloropicrin), these fumigants also sig...

DETECTION AND IMPLICATIONS OF EARLY AGROBACTERIUM TUMEFACIENS INFECTION OF PARADOX SEEDS AND SEEDLINGS

USDA-ARS?s Scientific Manuscript database

Paradox (Juglans hindsii x J. regia), the dominant rootstock used in California, USA walnut production, has many desirable horticultural characteristics, but is highly susceptible to crown gall. Crown gall, caused by the soil-borne bacterium Agrobacterium tumefaciens, can not be consistently control...

A population of endogenous pararetrovirus genomes in carrizo citrange

USDA-ARS?s Scientific Manuscript database

The complete genomes of three related endogenous pararetroviruses (EPRVs) were obtained by 454 sequencing of nucleic acid extracts from ‘Carrizo’citrange, used as a citrus rootstock. Numerous homologous sequences have been found in the sweet orange genome. The new EPRVs are most closely related to...

Susceptibility of Juglans Species andInterspecific Hybrids to Agrobacterium tumefaciens

Treesearch

James R. McKenna; Lynn Epstein

2003-01-01

Crown gall, caused by the common soil-borne bacterium Agrobacterium tumefaciens, can be an economic problem in walnut nurseries and production orchards in Caliiornia. The principal rootstocks used for commercial walnut production in California are the native Northern California black walnut, Juglans hindsii, and "Paradox,...

Propagation of Vaccinium arboreum for use as a rootstock for commercial blueberries

USDA-ARS?s Scientific Manuscript database

In recent years, there has been an increase in consumer demand for fresh blueberries throughout the year, which also increases the demand for sites suitable for growing blueberries. Commercial blueberries, particularly Vaccinium corymbosum, have very specific needs for optimum growth; hence, growing...

Identification and characterization of Citrus tristeza virus isolates breaking resistance in trifoliate orange in California

USDA-ARS?s Scientific Manuscript database

Most Citrus tristeza virus (CTV) isolates in California are biologically mild and symptomless in commercial cultivars on CTV tolerant rootstocks. However, to better define California CTV isolates showing divergent serological and genetic profiles, selected isolates were subjected to deep sequencing ...

Messenger RNA exchange between scions and rootstocks in grafted grapevines

USDA-ARS?s Scientific Manuscript database

We demonstrated the existence of genome-scale mRNA exchange in grafted grapevines, a woody fruit species with significant economic importance. By using diagnostic SNPs derived from high throughput genome sequencing, we identified more than three thousand genes transporting mRNAs across graft junctio...

Screening cut-stump control of Chinese tallowtree, sweetgum and yaupon with aminocyclopyrachlor

Treesearch

J. L. Yeiser; M. Link; J. Grogan

2012-01-01

Aminocyclopyrachlor (MAT28) was investigated for the potential control of unwanted woody rootstocks of Chinese tallowtree (Triadica sebifera), sweetgum (Liquidambar styraciflua), and yaupon (Ilex vomitoria). A cutstump application of MAT28+Brush and Basal Oil by Helena was tested against standard treatments: (1)...

Genetics, breeding and selection of rootstocks for Solanaceae and Cucurbitaceae

USDA-ARS?s Scientific Manuscript database

Limited availability of arable land and high market demand for off-season vegetables often leads to continuous cultivation and cultivation under unfavorable conditions such as too cold, wet, dry, or under low-light winter greenhouses. Successive cropping can increase salinity, the incidence of vege...

“Candidatus Phytoplasma pyri” affects behavior of Cacopsylla pyricola (Hemiptera: Psyllidae)

USDA-ARS?s Scientific Manuscript database

Pear psylla, Cacopsylla pyricola (Hemiptera: Psyllidae), is a key pest of pear and is a vector of "Candidatus Phytoplasma pyri", the pathogen associated with pear decline disease. Although commercial pear trees are grafted to Phytoplasma-resistant rootstock, a recent report indicated that many C. p...

Discovery of viruses and virus-like pathogens in pistachio using high-throughput sequencing

USDA-ARS?s Scientific Manuscript database

Pistachio (Pistacia vera L.) trees from the National Clonal Germplasm Repository (NCGR) and orchards in California were surveyed for viruses and virus-like agents by high-throughput sequencing (HTS). Analyses of 60 trees including clonal UCB-1 hybrid rootstock (P. atlantica × P. integerrima) identif...

Serial Transmission of Plant Viruses by Cutting During Grafting

USDA-ARS?s Scientific Manuscript database

Reciprocal grafts of two tomato (Solanum lycopersicum L.) cultivars were made by hand using commercial grafting techniques. The razor blade used to cut rootstock or scion was first contaminated by making a single cut on tomato plants infected with either tomato spotted wilt virus (TSWV) or tomato m...

Cacao genetic resources research at the USDA-ARS Tropical Agriculture Research Station, Mayaguez, Puerto Rico

USDA-ARS?s Scientific Manuscript database

The current USDA ARS Tropical Agriculture Research Station’s (TARS) cacao (Theobroma cacao L.) collection in Mayaguez, Puerto Rico, consists of 262 clonally propagated accessions. Each accession is represented by six individual trees grafted onto a common ‘Amelonado’ seedling rootstock and planted ...

Evaluation of wild Juglans species for crown gall resistance

USDA-ARS?s Scientific Manuscript database

Paradox, the most widely used rootstock in CA walnut production, is highly susceptible to the causal agent of crown gall (CG) Agrobacterium tumefaciens. The bacterial pathogen induces the formation of large tumors around the crown of the tree resulting in a reduction in both vigor and yield. If left...

Clonal Propagation of walnut rootstock genotypes for genetic improvement 2010

USDA-ARS?s Scientific Manuscript database

The soilborne bacterium Agrobacterium tumefaciens is the causal agent of crown gall disease of walnut. Large tumors located near the crown of the tree are hallmark symptoms induced by the bacterial pathogen. Untreated tumors can have an adverse effect on tree health resulting in reduced nut yield an...

CACAO (THEOBROMA CACAO L.) GENETIC RESOURCES RESEARCH AT THE USDA-ARS TROPICAL AGRICULTURE RESEARCH STATION

USDA-ARS?s Scientific Manuscript database

The current USDA ARS Tropical Agriculture Research Station’s cacao (Theobroma cacao) collection consists of 154 clonally propagated accessions. Each accession is represented by six individual trees grafted on Amelonado rootstocks and planted in a completely randomized block design with three blocks...

The challenge of salinity: Hope for the future with new avocado rootstocks

USDA-ARS?s Scientific Manuscript database

California avocado growers face diminishing returns in areas where Phytophthora root rot and saline irrigation water predominate. To help find answers to this production issue, a research trial was planted at the University of California, Riverside (UCR) in 2011. The goal of this trial was to determ...

Understanding genetic and physiological bases of salt tolerance in almond rootstocks

USDA-ARS?s Scientific Manuscript database

One of the biggest challenges California almond growers are facing is the irrigation water quality. Due to the reduced availability of good quality water, the use of alternative/ degraded waters is inevitable. The most important consideration for the use of degraded waters is the water salt concentr...

The vulnerability of US apple (Malus) genetic resources

USDA-ARS?s Scientific Manuscript database

Apple is one of the top three U.S. fruit crops in production and value. Apple production has high costs for land, labor and inputs, and orchards are a long-term commitment. Production is dominated by only a few apple scion cultivars and rootstocks, which increases susceptibility to dynamic external ...

Grafting Technique to Eliminate Rootstock Suckering of Grafted Tomatoes

USDA-ARS?s Scientific Manuscript database

Vegetable grafting has been proposed as a technique for avoiding disease problems in tomatoes in open field production. In this study we investigated the current use of grafting in an open field scenario and found a serious problem with the grafting techniques. In the Fall of 2007, commercially pr...

Graft Angle its Relationship to Tomato Plant Survival

USDA-ARS?s Scientific Manuscript database

Growing plants that can withstand the rigors of open field production is imperative. This study examines the relationship of tensile strength to graft angle and plant survival. Tomato seedlings of ‘FL47’ and ‘Rutgers’ were used as scions on ‘Roma’ rootstock under greenhouse and healing chamber con...

Inheritance of plum pox virus resistance in transgenic plums

USDA-ARS?s Scientific Manuscript database

We have studied the heritability of the virus transgene engineered in 'HoneySweet' plum through different cross-hybridization with two commercial cultivars of Prunus domestica (Prunier d’Ente 303 and Quetsche 2906) and one wild species, P. spinosa 2862, rootstock using 'HoneySweet' plum as the polle...

Resistance to phytophthora and graft compatibility with persian walnut among seedlings of chinese wingnut from different sources

USDA-ARS?s Scientific Manuscript database

Seedlings from seven open-pollinated selections of Chinese wingnut (Pterocarya stenoptera) (WN) representing collections of the USDA-ARS National Clonal Germplasm Repository at Davis CA and the University of California at Davis were evaluated as rootstocks for resistance to Phytophthora cinnamomi an...

Screening fusarium resistant rootstocks for plant parasitic nematode resistance

USDA-ARS?s Scientific Manuscript database

The phase out of methyl bromide has directed research toward alternative methods of managing soil-borne pathogens. A limiting factor in many watermelon producing regions is Fusarium wilt caused by the soil-borne fungi Fusarium oxysporum f.sp. niveum (FON). There is no varietal resistance to FON depl...

An evaluation of yellow-flowering magnolias and magnolia rootstocks

USDA-ARS?s Scientific Manuscript database

Yellow-flowering magnolias were evaluated for flower color, bloom duration and growth rate in USDA Hardiness Zone 6b. Of the thirty selections evaluated, all were reported to have yellow blooms; however, tepal color ranged from light pink with some yellow coloration, to creamy yellow to dark yellow....

NMR analysis reveals a wealth of metabolites in root-knot nematode resistant roots of Citrullus amarus watermelon plants

USDA-ARS?s Scientific Manuscript database

Citrullus amarus (CA) (previously known as Citrullus lanatus var. citroides) accessions collected in southern Africa are known to have resistance to root-knot nematodes (RKN) and are suitable rootstocks for grafted watermelon. A comparative metabolomics study was performed to identify unique metabol...

Alternative fumigants and grafting for tomato and double-cropped muskmelon production in Florida

USDA-ARS?s Scientific Manuscript database

A field trial was conducted at the USDA, ARS Farm in Fort Pierce, FL in a field infested with root-knot nematodes (RKN) (Meloidogyne incognita), soil-borne pathogens, and weeds. A split plot experiment with four replications was used to evaluate rootstock/scion combinations in fumigated and herbicid...

Integration of apple rootstock genotype with reduced Brassica seed meal application rates for replant disease control

USDA-ARS?s Scientific Manuscript database

Pre-plant soil application of Brassica seed meal (SM) formulations can provide fumigant level control of apple replant disease. However, due to high cost of the SM treatment relative to non-tarped soil fumigation, reduced application rates would likely accelerate commercial adoption of this technolo...

Clonal Propagation of Walnut Rootstock Genotypes for Genetic Improvement 2009

USDA-ARS?s Scientific Manuscript database

We produced over 3000 liner-sized plantlets of 26 genotypes for use in greenhouse screens and for growing in nurseries to a size large enough for grafting and use in orchard trials. In addition, over 1400 liner plantlets of 15 lines transformed for resistance to crown gall were produced for greenhou...

Effect of pre-plant soil fumigants on Agrobacterium tumefaciens, pythiaceous species, and subsequent soil recolonization by A. tumefaciens

USDA-ARS?s Scientific Manuscript database

Paradox (Juglans hindsii x J. regia), the dominant rootstock used in the California walnut industry, is susceptible to crown gall, caused by Agrobacterium tumefaciens. In practice, soil fumigation has been a common preplant management strategy for crown gall, but even an industry standard, methyl b...

Resistant Citrullus lanatus var. citroides Rootstocks for Managing Root-knot Nematodes in Grafted Watermelon

USDA-ARS?s Scientific Manuscript database

Southern root-knot nematode (RKN), Meloidogyne incognita, is an important re-emerging pest of watermelon. Several factors have contributed to re-emergence of RKN including: 1) ban of methyl bromide for soil fumigation; 2) reduced land area for crop rotation; and 3) continuous cropping of cucurbits u...

The effect of plant growth regulators on apple graft union flexural strength and flexibility

USDA-ARS?s Scientific Manuscript database

The apple rootstock ‘Geneva® 41’ (‘G.41’) forms weak graft unions with multiple scions. Exogenous plant growth regulators (PGR) can influence vascular differentiation and wood formation, and thus may improve graft union strength. A series of commercial and experimental PGR formulations were applied ...

Cryotherapy by encapsulation-dehydration is effective for in vitro eradication of latent viruses from ‘Marubakaido’ apple rootstock

USDA-ARS?s Scientific Manuscript database

Apple stem pitting virus (ASPV), Apple chlorotic leaf spot virus (ACLSV) and Apple stem grooving virus (ASGV) are several major viral pathogens of apple trees, responsible for substantial damage to the world's apple industry. This study aimed to evaluate the effectiveness of encapsulation-dehydratio...

Register of new fruit and nut cultivars list 45

USDA-ARS?s Scientific Manuscript database

The Register of New Fruit and Nut Cultivars is published in HortScience every one to two years and provides information on most new scion and rootstock cultivars of fruits and nuts that have not been previously provided in this format. New citrus cultivars have not been included since the list publ...

Genetic control of phyllotaxy phase shift in juvenile vines in a rootstock hybrid population

USDA-ARS?s Scientific Manuscript database

Grapevine seedlings initially display spiral phyllotaxy of true leaves, then undergo a shift to alternate phyllotaxy with the production of the first lateral meristems (typically tendrils). The node at which the shift from spiral to alternate phyllotaxy occurs varies from about the 4th to about the...

Vegetation responses to helicopter and ground based logging in blackwater floodplain forests

Treesearch

R.H. Jones; S.L. Stokes; B.G. Lockaby; John.A. Stanturf

2000-01-01

Logging in floodplains of low order, blackwater streams may damage cxisting seedlings and rootstocks, and create soil conditions that inhibit establishment and growth of regeneration after harvest. Removal of logs via helicopters has been advocated to minimize soil damage and facilitate rapid revegetation. We tested impacts of helicopter versus conventional skidder...

Resistance of ponderosa pine to western dwarf mistletoe in central Oregon

Treesearch

Robert F. Scharpf; Lewis F. Roth

1992-01-01

Ponderosa pines with little or no dwarf mistletoe in infested stands on the Deschutes, Ochoco, and Rogue River National Forests in Oregon were tested for resistance to dwarf mistletoe (Arceuthobium campylopodum). Small trees produced by grafting scions from the resistant and susceptible candidates onto seedling rootstock were planted in 1967-69...

Rooting and Other Characteristics of a Transgenic Walnut Hybrid (Juglans hindsii x J. regia) Rootstock Expressing rolABC

Treesearch

Kourosh Vahdati; James R. McKenna; Abhaya M. Dandekar; Charles A. Leslie; Sandie L. Uratsu; Wesley P. Hackett; Paola Negri; Gale H. McGranahan

2002-01-01

Walnuts (Juglans spp.) are difficult-to-root woody plants. The rolABC genes (rolA + rolB + rolC), derived from the bacteria Agrobacterium rhizogenes, have been shown to increase the rooting potential of other difficult-to-root woody plants. We inserted the...

Identification and translocation of metabolites from powdery mildew resistant rootstocks to susceptible watermelon scions using nuclear magnetic resonance spectroscopy

USDA-ARS?s Scientific Manuscript database

Watermelon (Citrullus lanatus), an important commercial crop, and nutritious fruit, is high in antioxidants, vitamins, and lycopene. Powdery mildew (PM) is a serious disease caused by Podosphaera xanthii, which significantly reduces watermelon production in the U.S. and other parts of the world. C...

Conferring high-temperature tolerance to nontransgenic tomato scions using graft transmission of RNA silencing of the fatty acid desaturase gene.

PubMed

Nakamura, Shinya; Hondo, Kana; Kawara, Tomoko; Okazaki, Yozo; Saito, Kazuki; Kobayashi, Kappei; Yaeno, Takashi; Yamaoka, Naoto; Nishiguchi, Masamichi

2016-02-01

We investigated graft transmission of high-temperature tolerance in tomato scions to nontransgenic scions from transgenic rootstocks, where the fatty acid desaturase gene (LeFAD7) was RNA-silenced. Tomato was transformed with a plasmid carrying an inverted repeat of LeFAD7 by Agrobacterium. Several transgenic lines showed the lower amounts of LeFAD7 RNA and unsaturated fatty acids, while nontransgenic control did not, and siRNA was detected in the transgenic lines, but not in control. These lines grew under conditions of high temperature, while nontransgenic control did not. Further, the nontransgenic plants were grafted onto the silenced transgenic plants. The scions showed less of the target gene RNA, and siRNA was detected. Under high-temperature conditions, these grafted plants grew, while control grafted plants did not. Thus, it was shown that high-temperature tolerance was conferred in the nontransgenic scions after grafting onto the silenced rootstocks. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Distribution of YLOID in soil-grapevine system (Vitis vinifera L.) as tool for geographical characterization of agro-food products. A two years case study on different grafting combinations.

PubMed

Pisciotta, Antonino; Tutone, Livia; Saiano, Filippo

2017-04-15

The knowledge of a chemistry relationship between the soil and the agricultural products is an important tool for the quality assessment of food. We studied YLOID (Y, La and lanthanoids), recognized as very useful tracers due their coherent and predictable behavior, to trace and evaluate their distribution from soil to the grape in Vitis vinifera L. Because much of the world's viticulture is based on grafting, and rootstocks have proved affect vine growth, yield, fruit and wine quality, we carried out experimental trials to analyse the YLOID distribution of two different red cultivars, grafted onto six different rootstocks, on the same soil. The YLOID amounts, the relationship Heavy vs Light YLOID and the pattern of YLOID were calculated. The results showed that the different grafting combinations were not able to induce significant differences in YLOID uptake from the soil maintaining the same fingerprint (with the exception of Eu). Copyright © 2016 Elsevier Ltd. All rights reserved.

In vitro clonal multiplication of an apple rootstock by culture of shoot apices and axillary buds.

PubMed

Kaushal, N; Modgil, M; Thakur, M; Sharma, D R

2005-06-01

In vitro clonal multiplication of apple rootstock MM 111 using axillary buds and shoot apices were carried out. Vegetative axillary buds of the size of 0.2-2.0 cm and shoot apices measuring 4 mm in length were initiated to shoot proliferation on MS medium supplemented with BA (0.5 - 1.0 mgl(-1)), GA3(0.5 mgl(-1)), with or without IBA(0.05 - 0.1 mgl(-1)). Small size explants showed less phenol exudation and less contamination. Following establishment phase, the small shoots emerged from explants were subcultured on MS medium supplemented with different combinations and concentrations of growth regulators. BA (1.0 mgl(-1)) and GA3 (0.5 mgl(-1)) combination showed highest multiplication rate (1:5), andcl also produced longer shoots. Two step rooting was done by transferring microcuttings to auxin free solid medium after root initiation in dark on 1/2 strength MS liquid medium containing IBA (0.5 mgl(-1) ). Rooted plantlets were transferred to peat containing paper cups and resulting plants of MM 111 acclimated successfully for transfer to field.

Systemic Induction of Photosynthesis via Illumination of the Shoot Apex Is Mediated Sequentially by Phytochrome B, Auxin and Hydrogen Peroxide in Tomato1[OPEN

PubMed Central

Guo, Zhixin; Ahammed, Golam Jalal; Wang, Mengmeng; Zhou, Jie; Xia, Xiaojian; Shi, Kai; Yin, Xueren; Chen, Kunsong; Yu, Jingquan; Zhou, Yanhong

2016-01-01

Systemic signaling of upper leaves promotes the induction of photosynthesis in lower leaves, allowing more efficient use of light flecks. However, the nature of the systemic signals has remained elusive. Here, we show that preillumination of the tomato (Solanum lycopersicum) shoot apex alone can accelerate photosynthetic induction in distal leaves and that this process is light quality dependent, where red light promotes and far-red light delays photosynthetic induction. Grafting the wild-type rootstock with a phytochome B (phyB) mutant scion compromised light-induced photosynthetic induction as well as auxin biosynthesis in the shoot apex, auxin signaling, and RESPIRATORY BURST OXIDASE HOMOLOG1 (RBOH1)-dependent hydrogen peroxide (H2O2) production in the systemic leaves. Light-induced systemic H2O2 production in the leaves of the rootstock also was absent in plants grafted with an auxin-resistant diageotropica (dgt) mutant scion. Cyclic electron flow around photosystem I and associated ATP production were increased in the systemic leaves by exposure of the apex to red light. This enhancement was compromised in the systemic leaves of the wild-type rootstock with phyB and dgt mutant scions and also in RBOH1-RNA interference leaves with the wild type as scion. Silencing of ORANGE RIPENING, which encodes NAD(P)H dehydrogenase, compromised the systemic induction of photosynthesis. Taken together, these results demonstrate that exposure to red light triggers phyB-mediated auxin synthesis in the apex, leading to H2O2 generation in systemic leaves. Enhanced H2O2 levels in turn activate cyclic electron flow and ATP production, leading to a faster induction of photosynthetic CO2 assimilation in the systemic leaves, allowing plants better adaptation to the changing light environment. PMID:27550998

Eradicating Understory Hardwoods By Repeated Prescribed Burning

Treesearch

Charles X. Grano

1970-01-01

In a loblolly-shorleaf pine stand contained abundant litter, one winter fire killed 94 percent of the stems of understory hardwoods up to 3.5 inches in diameter at teh base. Prolific sprouting ensued. Eleven annual summer burns eliminated sprouting on 85 percent of the rootstocks, and seven biennial summer burns eliminated sprouting on 59 percent of them.

Performance of Geneva® apple rootstock selections with ‘Brookfield Gala’ and ‘Cripps Pink’ on a tall spindle system

USDA-ARS?s Scientific Manuscript database

High density orchard systems have become the standard for new plantings in many apple production regions due to their earlier yield and higher cumulative yields which results in greater return on investments. Growers in the Mid-Atlantic region have unique challenges compared to northern production r...

Grafting and Paladin™ Pic-21 for nematode and weed management in vegetable production

USDA-ARS?s Scientific Manuscript database

Field trials were conducted over two years in a Meloidogyne incognita-infested field to evaluate the combined use of grafting and Paladin™ (DMDS:chloropicrin) for root-knot nematode and weed control in tomato and melon. Tomato rootstocks evaluated were; ‘TX301’, ‘Multifort’, and ‘Aloha’. ‘Florida 47...

Putative resistance gene markers associated with quantitative trait loci for fire blight resistance in Malus 'Robusta 5' accessions

USDA-ARS?s Scientific Manuscript database

Breeding of fire blight resistant scions and rootstocks is a goal of several international apple breeding programs, as options are limited for management of this destructive disease caused by the bacterial pathogen Erwinia amylovora. A broad, large effect QTL for fire blight resistance has been pre...

Detection of a new luteovirus in imported nectarine Trees: A case study to propose adoption of metagenomics in post-entry quarantine

USDA-ARS?s Scientific Manuscript database

In spring 2013, five year-old nectarine (Prunus persica) trees, grafted on peach rootstock Nemaguard, were found stunted in a propagation block in California. These trees had been propagated from budwood of three nectarine cultivars imported from France and cleared through the post-entry quarantine ...

Looking for something new? Check out background results of potential new cultivars for California

USDA-ARS?s Scientific Manuscript database

This report compiles basic background information on the scion and rootstock varieties most recently released or scheduled for release by the CCPP. Cultivars are organized by type and in the same order as the CCPP budwood order form, and then by Variety index (VI) number with the earliest ones on th...

Pyrano-isoflavones with erectile-dysfunction activity from Eriosema kraussianum.

PubMed

Drewes, Siegfried E; Horn, Marion M; Munro, Orde Q; Dhlamini, Jabu T B; Meyer, J J Marion; Rakuambo, N Christopher

2002-04-01

Five pyrano-isoflavones have been isolated from the rootstock of Eriosema kraussianum N. E. Br (Papilionaceae). Spectral data and single crystal X-ray analyses were used for structural elucidation. The most active of the compounds had an activity of 75% of that found in Viagra in the erectile dysfunction test on rabbit penile smooth muscle.

Evaluation of virus resistant rootstocks to manage watermelon vine decline and diseases caused by other potyviruses

USDA-ARS?s Scientific Manuscript database

Watermelon vine decline caused by Squash vein yellowing virus (SqVYV) is an emerging disease that has caused severe losses to Florida watermelon growers in recent years. Papaya ringspot virus type W (PRSV-W) is one of several watermelon-infecting potyviruses long present in the southeastern U.S. L...

Transpiration and Multiple Use Management of Thinned Emory Oak Coppice

Treesearch

D. Catlow Shipek; Peter F. Ffolliott; Gerald J. Gottfried; Leonard F. DeBano

2004-01-01

The effects of thinning Emory oak (Quercus emoryi) coppice on transpiration have been estimated by the heat-pulse velocity (HPV) method. Rootstocks of trees harvested for fuelwood were thinned to one, two, or three dominant stump-sprouts or left as unthinned controls. Differences in transpiration rates of the thinned coppice were found for each...

Damping-off in forest nurseries

Treesearch

Carl Hartley

1921-01-01

Damping-off is the commonest English name for a symptomatic group of diseases affecting great numbers of plant species of widely separated phylogenetic groups. It is commonly used for any disease which results in the rapid decay of young succulent seedlings or soft cuttings. Young shoots from underground rootstocks may also be damped-off before they break through the...

Nitrogen requirements of Pinot noir based on growth parameters, must composition, and fermentation behavior

USDA-ARS?s Scientific Manuscript database

A study to reassess the nitrogen (N) requirements for Pinot noir was carried out using a pot-in-pot vineyard where N inputs were carefully controlled. Pinot noir grafted on 101-14 rootstock was exposed to five levels of N supply delivered via fertigation beginning in their fourth growing season, and...

Causative Role of Grapevine Red Blotch Virus in Red Blotch Disease.

PubMed

Yepes, Luz Marcela; Cieniewicz, Elizabeth; Krenz, Björn; McLane, Heather; Thompson, Jeremy R; Perry, Keith Lloyd; Fuchs, Marc

2018-05-17

Grapevine red blotch virus (GRBV) has a monopartite single-stranded DNA genome and is the type species of the genus Grablovirus in the family Geminiviridae. To address the etiological role of GRBV in the recently recognized red blotch disease of grapevine, infectious GRBV clones were engineered from the genome of each of the two previously identified phylogenetic clades for Agrobacterium tumefaciens-mediated inoculations of tissue culture-grown Vitis spp. plants. Following agroinoculation and one or two dormancy cycles, systemic GRBV infection was detected by multiplex polymerase chain reaction (PCR) in Vitis vinifera exhibiting foliar disease symptoms but not in asymptomatic vines. Infected rootstock genotype SO4 (V. berlandieri × V. riparia) exhibited leaf chlorosis and cupping, while infection was asymptomatic in agroinoculated 110R (V. berlandieri × V. rupestris), 3309C (V. riparia × V. rupestris), and V. rupestris. Spliced GRBV transcripts of the replicase-associated protein coding region accumulated in leaves of agroinfected vines, as shown by reverse-transcription PCR; this was consistent with systemic infection resulting from virus replication. Additionally, a virus progeny identical in nucleotide sequence to the infectious GRBV clones was recovered from agroinfected vines by rolling circle amplification, cloning, and sequencing. Concomitantly, subjecting naturally infected grapevines to microshoot tip culture resulted in an asymptomatic plant progeny that tested negative for GRBV in multiplex PCR. Altogether, our agroinoculation and therapeutic experiments fulfilled Koch's postulates and revealed the causative role of GRBV in red blotch disease.

Untapped richness in Erik H. Erikson's rootstock.

PubMed

Kivnick, Helen Q; Wells, Courtney K

2014-02-01

Erik H. Erikson published his groundbreaking theory of 8 stages of lifelong psychosocial development in 1950. His theory expanded psychoanalytic concepts of psychosexual development to include the importance of social dynamics; it transcended then-current thinking that psychological development culminated in early adulthood, acknowledging that systematic human development continues throughout the entire life cycle. The theory made Erikson a pioneer in developmental psychology. His last authored book, Vital Involvement in Old Age, rearticulated and elaborated 3 principles that, in different words, are rooted in his original theory of healthy life cycle development: (1) Dynamic Balance of Opposites; (2) Vital Involvement; and (3) Life in Time. Using a lens informed by knowledge gained over the past 30 years and by reflections of one of the original researchers on that project, the current manuscript seeks to spark new interest in Erikson's late-life contribution. It explains the principles in new detail, links them to relevant research, and suggests ways they could enable Erikson's ideas to further enrich gerontological practice and research.

Characterization biometric and morphophysiological of Peach rootstock seeds using images of their seedling vigor.

PubMed

Souza, Aline Das Graças; Smiderle, Oscar Jose; Bianchi, Valmor Joao

2018-04-26

This study aimed to evaluate the efficiency of using the computerized imaging seed analysis system (SAS) in the biometric and morphophysiological characterization of seeds and the initial growth of seedlings from peach rootstocks. The experimental design was completely randomized with five replicates of 20 seeds. The variables analyzed were degree of seed humidity, length and width of seeds measured by SAS technology and manual measurements, mean germination time, germination percentage, radicle length and width, taproot length, length of the aerial part and taproot/aerial part ratio. The highest seed length, germination percentage (100%) and lower germination time (11.3), were obtained with the cv. Capdeboscq while, 'Tsukuba 1', 2' and 3' had intermediate seedlings length, varying from 1.55 to 1.65 cm with mean germination times between 14.5 and 18.0 days and average germination percentage of 96%. The computerized analysis of images is fast and efficient for biometric evaluations such as seed width and length, as well as initial growth of peach tree seedlings. The cvs Capdeboscq, Flordaguard and Tsukuba 2 presented greater radicle width, length and a mean taproot/aerial part ratio equal to 2, as well as higher number of adventitious roots, which indicated a strong positive correlation between radicle length, taproot length and initial seedling growth. The continuity of the research will certainly allow the development of reliable procedures for other species, besides allowing the identification of wider alternatives for the use of this system for the expansion of knowledge in the areas of physiology and evaluation of the physiological potential of seeds. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Peach (Prunus persica L.).

PubMed

Sabbadini, Silvia; Pandolfini, Tiziana; Girolomini, Luca; Molesini, Barbara; Navacchi, Oriano

2015-01-01

Until now, the application of genetic transformation techniques in peach has been limited by the difficulties in developing efficient regeneration and transformation protocols. Here we describe an efficient regeneration protocol for the commercial micropropagation of GF677 rootstock (Prunus persica × Prunus amygdalus). The method is based on the production, via organogenesis, of meristematic bulk tissues characterized by a high competence for shoot regeneration. This protocol has also been used to obtain GF677 plants genetically engineered with an empty hairpin cassette (hereafter indicated as hp-pBin19), through Agrobacterium tumefaciens-mediated transformation. After 7-8 months of selection on media containing kanamycin, we obtained two genetically modified GF677 lines. PCR and Southern blot analyses were performed to confirm the genetic status.

Allotetraploid hybrids between citrus and seven related genera produced by somatic hybridization.

PubMed

Grosser, J W; Mourao-Fo, F A; Gmitter, F G; Louzada, E S; Jiang, J; Baergen, K; Quiros, A; Cabasson, C; Schell, J L; Chandler, J L

1996-04-01

We have developed an efficient protoplast-fusion method to produce somatic hybrid allopolyploid plants that combine Citrus with seven related genera, including four that are sexually incompatible. In this paper we report the creation of 18 new allotetraploid hybrids of Citrus, including ten among sexually incompatible related genera, that may have direct cultivar potential as improved citrus rootstocks. All hybrids were confirmed by cytological and RAPD analyses. If fertile, the attributes of these hybrids may be amenable to further genetic manipulation by breeding at the tetraploid level. Wide somatic hybridization of Citrus via protoplast fusion bypasses biological barriers to the natural allopolyploidization of Citrus, and creates new evolutionary opportunities that would be difficult or impossible to achieve by natural or conventional hybridization.

Spot drip application of dimethyl disulfide as post-planting treatment for the control of plant-parasitic nematodes and soilborne pathogens in grape production

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Plant-parasitic nematodes and soilborne pathogens can reduce the overall productivity in grape production. Not all grape growers apply soil fumigants before planting and there is no single rootstock resistant to all nematode species. The aim of this investigation was to evaluate the effe...

Environmental effects on fruit ripening and average fruit weight for three peach cultivars

USDA-ARS?s Scientific Manuscript database

Three peach cultivars, ‘Crimson Lady’ (early), ‘Redhaven’ (mid-season) and ‘Cresthaven’ (late), were planted at twelve locations within the USA in 2009. All trees were grafted on ‘Lovell’ rootstock and came from the same nursery. Five trees of each cultivar were planted at a spacing of 6m by 5m at e...

Deep sequencing of viral small-RNAs of citrus tristeza virus (CTV) reveals genomic differences between two Italian isolates of CTV

USDA-ARS?s Scientific Manuscript database

A recent Citrus tristeza virus (CTV) epidemic of quick decline (QD) killed many sweet orange trees grafted on sour orange rootstock in Sicily but left some asymptomatic trees in the same field. Recent reports indicated cross-protection involves exclusion of a severe CTV strain by a mild strain of th...

Incidence of Agrobacterium tumefaciens biovar 1 in and on ‘Paradox’ (Juglans hindsii x Juglans regia) walnut seed collected from commercial nurseries

USDA-ARS?s Scientific Manuscript database

The walnut rootstock Paradox (Juglans hindsii (Jeps) Rehder x J. regia L.) is susceptible to Agrobacterium tumefaciens (7) which often results in a high incidence of crown gall in nursery or walnut production orchards. Though A. tumefaciens is susceptible to the commonly used preplant soil fumigant...

Calculation of diagnostic parameters of advanced serological and molecular tissue-print methods for detection of Citrus tristeza virus. A model for other plant pathogens

USDA-ARS?s Scientific Manuscript database

Citrus tristeza virus (CTV) is one of the most important virus diseases which affect citrus. Control of CTV in Spain and central California is achieved by planting virus-free citrus on CTV-tolerant or -resistant rootstocks. Quarantine and certification programs remain essential to avoid importation ...

Abundance and distribution of vegetation under four hardwood stands in north-central West Virginia

Treesearch

G.W. Wendel; G.W. Wendel

1987-01-01

Forest floor samples were collected from four hardwood forest stands in West Virginia to study species composition, abundance, and distribution of vegetation that originated from seeds, rootstocks, rhizomes, and so on. The abundance and distribution of plants on square-foot sections of forest floor that were lifted and moved to the greenhouse indicate that under the...

DNA markers and pollen morphology reveal that Praecitrullus fistulosus is more closely related to Benincasa hispida than to Citrullus spp.

USDA-ARS?s Scientific Manuscript database

The round melon Praecitrullus fistulosus (Stocks) Pangalo has been cultivated in Asia since ancient times and has been considered an underexploited crop in the western world. In the US, there is an increased interest in using P. fistulosus as a commercial vegetable, and possibly as a rootstock for ...

Air method measurements of apple vessel length distributions with improved apparatus and theory

Treesearch

Shabtal Cohen; John Bennink; Mel Tyree

2003-01-01

Studies showing that rootstock dwarfing potential is related to plant hydraulic conductance led to the hypothesis that xylem properties are also related. Vessel length distribution and other properties of apple wood from a series of varieties were measured using the 'air method' in order to test this hypothesis. Apparatus was built to measure and monitor...

Grafting influences on early acorn production in swamp white oak (Quercus bicolor Wild.)

Treesearch

Mark V. Coggeshall; J.W. Van Sambeek; H.E. Garrett

2008-01-01

Early fruiting of swamp white oak planting stock has been observed. The potential to exploit this trait for wildlife enhancement purposes was evaluated in a grafting study. Scions from both precocious and non-precocious ortets were grafted onto a series of related seedling rootstock sources. Acorn production was recorded through age 4 years. Acorn productivity of the...

Females and males of root-parasitic cyst nematodes induce different symplasmic connections between their syncytial feeding cells and the phloem in Arabidopsis thaliana.

PubMed

Hofmann, Julia; Grundler, Florian M W

2006-01-01

Root syncytia induced by the beet cyst nematode Heterodera schachtii were thought to be symplasmically isolated. A recent study with mobile and immobile GFP constructs expressed in transgenic Arabidopsis plants under the control of pAtSUC2 showed that only mobile GFP could be detected in syncytia and suggested the existence of plasmodesmata between syncytia and the phloem. In the present study the existence of plasmodesmata between syncytia and the phloem is proven by grafting experiments. This technique rules out the possibility that GFP accumulation in syncytia is due to GFP expression in syncytia. Mobile GFP could be followed from transgenic scions carrying a pAtSUC2-gfp fusion construct via wild-type rootstocks into nematode-induced syncytia. While GFP could be detected in all syncytia associated to female nematodes, it was never observed in syncytia of male juveniles. As no GFP-mRNA could be detected in the rootstock we postulate that GFP as protein entered syncytia of females via plasmodesmata, while the protein was excluded from syncytia of male juveniles by plasmodesmata with a lower size exclusion limit.

An apple rootstock overexpressing a peach CBF gene alters growth and flowering in the scion but does not impact cold hardiness or dormancy

USDA-ARS?s Scientific Manuscript database

The C-repeat Binding Factor (CBF) transcription factor is involved in responses to low temperature and water deficit in many plant species. Overexpression of CBF genes leads to enhanced freezing tolerance and growth inhibition in many species. The overexpression of a peach CBF (PpCBF1) gene in a t...

Comparative study of the protein profiles of Sunki mandarin and Rangpur lime plants in response to water deficit.

PubMed

Oliveira, Tahise M; da Silva, Fernanda R; Bonatto, Diego; Neves, Diana M; Morillon, Raphael; Maserti, Bianca E; Filho, Mauricio A Coelho; Costa, Marcio G C; Pirovani, Carlos P; Gesteira, Abelmon S

2015-03-03

Rootstocks play a major role in the tolerance of citrus plants to water deficit by controlling and adjusting the water supply to meet the transpiration demand of the shoots. Alterations in protein abundance in citrus roots are crucial for plant adaptation to water deficit. We performed two-dimensional electrophoresis (2-DE) separation followed by LC/MS/MS to assess the proteome responses of the roots of two citrus rootstocks, Rangpur lime (Citrus limonia Osbeck) and 'Sunki Maravilha' (Citrus sunki) mandarin, which show contrasting tolerances to water deficits at the physiological and molecular levels. Changes in the abundance of 36 and 38 proteins in Rangpur lime and 'Sunki Maravilha' mandarin, respectively, were observed via LC/MS/MS in response to water deficit. Multivariate principal component analysis (PCA) of the data revealed major changes in the protein profile of 'Sunki Maravilha' in response to water deficit. Additionally, proteomics and systems biology analyses allowed for the general elucidation of the major mechanisms associated with the differential responses to water deficit of both varieties. The defense mechanisms of Rangpur lime included changes in the metabolism of carbohydrates and amino acids as well as in the activation of reactive oxygen species (ROS) detoxification and in the levels of proteins involved in water stress defense. In contrast, the adaptation of 'Sunki Maravilha' to stress was aided by the activation of DNA repair and processing proteins. Our study reveals that the levels of a number of proteins involved in various cellular pathways are affected during water deficit in the roots of citrus plants. The results show that acclimatization to water deficit involves specific responses in Rangpur lime and 'Sunki Maravilha' mandarin. This study provides insights into the effects of drought on the abundance of proteins in the roots of two varieties of citrus rootstocks. In addition, this work allows for a better understanding of the molecular basis of the response to water deficit in citrus. Further analysis is needed to elucidate the behaviors of the key target proteins involved in this response.

QTL analysis of citrus tristeza virus-citradia interaction.

PubMed

Asins, M J; Bernet, G P; Ruiz, C; Cambra, M; Guerri, J; Carbonell, E A

2004-02-01

Citrus tristeza virus (CTV) has caused the death of millions of trees grafted on sour orange ( Citrus aurantium). However, this rootstock is very well adapted to the Mediterranean, semi-arid conditions. The aim of the present research is to genetically analyze the accumulation of CTV in a progeny derived from the cross between C. aurantium and Poncirus trifoliata, both resistant to CTV isolate T-346. Graft propagation of 104 hybrids was done on healthy sweet orange as a rootstock. Three months later, each rootstock was graft inoculated with two patches of infected tissue (isolate T-346). One, 2, and sometimes, 3 and 4 years after inoculation, hybrids and infected patches were tested for CTV by tissue-blot immuno-assay. Additionally, CTV multiplication was evaluated every year as the optical density of double-antibody sandwich enzyme-linked immuno-sorbent assay reactions. Linkage maps for P. trifoliata based on 63 markers, and for C. aurantium based on 157 markers, were used. Most molecular markers were microsatellites and IRAP (inter-retrotransposon amplified polymorphisms). Some analogues of resistance and expressed sequences were also included for candidate gene analysis. Resistance against CTV was analyzed as a quantitative trait (CTV accumulation) by QTL (quantitative trait loci) analysis to avoid the assumption of monogenic control. Three major resistance QTLs were detected where the P. trifoliata resistance gene, Ctv-R, had been previously located in other progenies. Up to five minor QTLs were detected ( Ctv-A(1) to Ctv-A(5)). A significant epistatic interaction involving Ctv-R(1) and Ctv-A(1) was also found. An analogue of a resistance gene is a candidate for Ctv-A(3), and two expressed sequences are candidates for Ctv-A(1) and Ctv-A(5). Single-strand conformational polymorphism analysis of CTV genes QTL P20 and P25 (coat protein) in susceptible hybrids, was carried out to test whether or not any QTL accumulation was a defeated resistance gene. Since the same haplotype of the virus was visualized independently on the CTV titer, differences in the amount of virions are not explained through the selection of CTV genotypes by the host, but through differences among citradias in CTV replication and/or movement.

Development of a dense SNP-based linkage map of an apple rootstock progeny using the Malus Infinium whole genome genotyping array.

PubMed

Antanaviciute, Laima; Fernández-Fernández, Felicidad; Jansen, Johannes; Banchi, Elisa; Evans, Katherine M; Viola, Roberto; Velasco, Riccardo; Dunwell, Jim M; Troggio, Michela; Sargent, Daniel J

2012-05-25

A whole-genome genotyping array has previously been developed for Malus using SNP data from 28 Malus genotypes. This array offers the prospect of high throughput genotyping and linkage map development for any given Malus progeny. To test the applicability of the array for mapping in diverse Malus genotypes, we applied the array to the construction of a SNP-based linkage map of an apple rootstock progeny. Of the 7,867 Malus SNP markers on the array, 1,823 (23.2%) were heterozygous in one of the two parents of the progeny, 1,007 (12.8%) were heterozygous in both parental genotypes, whilst just 2.8% of the 921 Pyrus SNPs were heterozygous. A linkage map spanning 1,282.2 cM was produced comprising 2,272 SNP markers, 306 SSR markers and the S-locus. The length of the M432 linkage map was increased by 52.7 cM with the addition of the SNP markers, whilst marker density increased from 3.8 cM/marker to 0.5 cM/marker. Just three regions in excess of 10 cM remain where no markers were mapped. We compared the positions of the mapped SNP markers on the M432 map with their predicted positions on the 'Golden Delicious' genome sequence. A total of 311 markers (13.7% of all mapped markers) mapped to positions that conflicted with their predicted positions on the 'Golden Delicious' pseudo-chromosomes, indicating the presence of paralogous genomic regions or mis-assignments of genome sequence contigs during the assembly and anchoring of the genome sequence. We incorporated data for the 2,272 SNP markers onto the map of the M432 progeny and have presented the most complete and saturated map of the full 17 linkage groups of M. pumila to date. The data were generated rapidly in a high-throughput semi-automated pipeline, permitting significant savings in time and cost over linkage map construction using microsatellites. The application of the array will permit linkage maps to be developed for QTL analyses in a cost-effective manner, and the identification of SNPs that have been assigned erroneous positions on the 'Golden Delicious' reference sequence will assist in the continued improvement of the genome sequence assembly for that variety.

Nematode and grape rootstock interactions including an improved understanding of tolerance.

PubMed

McKenry, M V; Anwar, Safdar A

2006-09-01

Sixteen cultivars of grape were screened over a two-year period in the presence or absence of 10 different nematode populations. Populations of Meloidogyne spp., Xiphinema index, and Mesocriconema xenoplax developed more rapidly and caused greater damage than populations of X. americanum and Tylenchulus semipenetrans. Populations of mixed Meloidogyne spp. having a history of feeding on grape were among the fastest developing populations. Tolerance to nematode parasitism appeared to be based on different mechanisms. Slow developing, less pathogenic nematode populations often stimulated vine growth, thus vines appeared to possess tolerance. Likewise, cultivars selected for nematode resistance often stimulated vine growth when fed upon by the nematode. However, tolerance sources that resulted from nematode resistance are vulnerable due to the occurrence of populations that break resistance mechanisms. Growth of cultivars with phylloxera (Daktalospharia vitifoliae) resistance was unchanged by the presence of nematodes, indicating that phylloxera resistance may provide a useful source of nematode relief. These and several additional sources of specific tolerance are discussed.

Nematode and Grape Rootstock Interactions Including an Improved Understanding of Tolerance

PubMed Central

McKenry, M.V.; Anwar, Safdar A.

2006-01-01

Sixteen cultivars of grape were screened over a two-year period in the presence or absence of 10 different nematode populations. Populations of Meloidogyne spp., Xiphinema index, and Mesocriconema xenoplax developed more rapidly and caused greater damage than populations of X. americanum and Tylenchulus semipenetrans. Populations of mixed Meloidogyne spp. having a history of feeding on grape were among the fastest developing populations. Tolerance to nematode parasitism appeared to be based on different mechanisms. Slow developing, less pathogenic nematode populations often stimulated vine growth, thus vines appeared to possess tolerance. Likewise, cultivars selected for nematode resistance often stimulated vine growth when fed upon by the nematode. However, tolerance sources that resulted from nematode resistance are vulnerable due to the occurrence of populations that break resistance mechanisms. Growth of cultivars with phylloxera (Daktalospharia vitifoliae) resistance was unchanged by the presence of nematodes, indicating that phylloxera resistance may provide a useful source of nematode relief. These and several additional sources of specific tolerance are discussed. PMID:19259534

Nucleoli from growing oocytes support the development of enucleolated full-grown oocytes in the pig.

PubMed

Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi

2010-02-01

Recent research has shown that the maternal nucleolus is essential for embryonic development. The morphology of the nucleolus in growing oocytes differs from that in full-grown oocytes. We determined the ability of nucleoli from growing oocytes to substitute for nucleoli of full-grown oocytes in terms of supporting embryonic development in this study. Growing (around 100 microm in diameter) and full-grown porcine oocytes (120 microm) were collected from small (0.6-1.0 mm) and large antral follicles (4-5 mm), respectively. The nucleolus was aspirated from full-grown oocytes by micromanipulation, and the resulting enucleolated oocytes were matured to metaphase II; the nucleoli originating from full-grown and growing oocytes were then injected into the oocytes. The Chromatin of growing oocytes was aspirated with the nucleolus during the enucleolation process. Growing oocytes were thus treated with actinomycin D to release the chromatin from their nucleoli, and the nucleoli were collected and transferred to the enucleolated and matured full-grown oocytes. After activation by electro-stimulation, nucleoli were formed in pronuclei of sham-operated oocytes. Enucleolated oocytes that had been injected with nucleoli from either full-grown or growing, however, did not form any nucleoli in the pronuclei. No enucleolated oocytes developed to blastocysts, whereas enucleolated oocytes injected with nucleoli from full-grown oocytes (15%) or growing oocytes (18%) developed to blastocysts. These results indicate that the nucleoli from growing oocytes can substitute for nucleoli from full-grown oocytes during early embryonic development. (c) 2009 Wiley-Liss, Inc.

Rejuvenation of Sequoia sempervirens by Repeated Grafting of Shoot Tips onto Juvenile Rootstocks in Vitro 1

PubMed Central

Huang, Li-Chun; Lius, Suwenza; Huang, Bau-Lian; Murashige, Toshio; Mahdi, El Fatih M.; Van Gundy, Richard

1992-01-01

Repeated grafting of 1.5-centimeter long shoot tips from an adult Sequoia sempervirens tree onto fresh, rooted juvenile stem cuttings in vitro resulted in progressive restoration of juvenile traits. After four successive grafts, stem cuttings of previously adult shoots rooted as well, branched as profusely, and grew with as much or more vigor as those of seedling shoots. Reassays disclosed retention for 3 years of rooting competence at similar levels as originally restored. Adventitious shoot formation was remanifested and callus development was depressed in stem segments from the repeatedly grafted adult. The reversion was associated with appearance and disappearance of distinctive leaf proteins. Neither gibberellic acid nor N6-beneyladenine as nutrient supplements duplicated the graft effects. ImagesFigure 2Figure 5Figure 8 PMID:16668609

Volatile Organic Compound (VOC) profiling of Citrus tristeza virus (CTV) infection in sweet orange citrus varietals using thermal desorption gas chromatography time of flight mass spectrometry (TD-GC/TOF-MS)

USDA-ARS?s Scientific Manuscript database

Citrus tristeza virus (CTV) is a plant pathogen which predominately infects economically important citrus crops such as sweet orange, clementine, lime and grapefruit varietals. Within the last 70 years, an estimated 100 million citrus trees on sour orange rootstock have been destroyed due to CTV inf...

Morphological and Cytomolecular Assessment of Intraspecific Variability in Scarlet Eggplant ( Solanum aethiopicum L.)

Treesearch

Hamidou F. Sakhanokho; M. Nurul Islam-Faridi; Eugene K. Blythe; Barbara J. Smith; Kanniah Rajasekaran; M. A. Majid

2014-01-01

Solanum aethiopicum L. is native to sub-Saharan Africa but is now found in many parts of the world. It is used for food, medicinal, and ornamental purposes. It has also been used as a rootstock for tomato and common eggplant because of its resistance to certain pathogens. However, very little is known about its genetics, so the purpose of this work was to assess...

Comparative Programs for Arthropod, Disease and Weed Management in New York Organic Apples

PubMed Central

Agnello, Arthur; Cox, Kerik; Lordan, Jaume; Francescatto, Poliana; Robinson, Terence

2017-01-01

Organic apple production in the eastern US is small and is mostly based on existing varieties, which are susceptible to scab, and rootstocks, which are susceptible to fire blight. This requires numerous sprays per year of various pesticides to produce acceptable fruit. From 2014 to 2016, we tested different arthropod, disease and weed management programs in an advanced tall spindle high-density production system that included disease-resistant cultivars and rootstocks, in an organic research planting of apples in Geneva, New York. Arthropod and disease management regimens were characterized as Advanced Organic, Minimal Organic, or Untreated Control. Results varied by year and variety, but, in general, the Advanced program was more effective than the Minimal program in preventing damage from internal-feeding Lepidoptera, plum curculio, and obliquebanded leafroller, and less effective than the Minimal program against damage by foliar insects. Both organic programs provided comparable control of sooty blotch, cedar apple rust, and fire blight, with some variability across cultivars and years. The advanced selection CC1009 and Modi seemed to possess complete resistance to cedar apple rust, while Pristine had partial resistance. For weed control, bark chip mulch, organic soap sprays, and limonene sprays tended to be most effective, while mechanical tillage and flame weeding had lower success. PMID:28869562

Lost in Transit: Long-Distance Trafficking and Phloem Unloading of Protein Signals in Arabidopsis Homografts[OPEN

PubMed Central

Gustin, Marie-Paule; Molnar, Attila; Oparka, Karl J.

2016-01-01

In addition to moving sugars and nutrients, the phloem transports many macromolecules. While grafting and aphid stylectomy experiments have identified many macromolecules that move in the phloem, the functional significance of phloem transport of these remains unclear. To gain insight into protein trafficking, we micrografted Arabidopsis thaliana scions expressing GFP-tagged chloroplast transit peptides under the 35S promoter onto nontransgenic rootstocks. We found that plastids in the root tip became fluorescent 10 d after grafting. We obtained identical results with the companion cell-specific promoter SUC2 and with signals that target proteins to peroxisomes, actin, and the nucleus. We were unable to detect the respective mRNAs in the rootstock, indicating extensive movement of proteins in the phloem. Outward movement from the root protophloem was restricted to the pericycle-endodermis boundary, identifying plasmodesmata at this interface as control points in the exchange of macromolecules between stele and cortex. Intriguingly, signals directing proteins to the endoplasmic reticulum and Golgi apparatus from membrane-bound ribosomes were not translocated to the root. It appears that many organelle-targeting sequences are insufficient to prevent the loss of their proteins into the translocation stream. Thus, nonspecific loss of proteins from companion cells to sieve elements may explain the plethora of macromolecules identified in phloem sap. PMID:27600534

Vigor for In Vitro Culture Traits in S. melongena   ×   S. aethiopicum Hybrids with Potential as Rootstocks for Eggplant

PubMed Central

Prohens, Jaime

2014-01-01

Hybrids of Solanum melongena and S. aethiopicum are of interest as rootstocks of eggplant, as they are highly vigorous and can incorporate resistance to several diseases. However, hybridization between both species is difficult. Therefore, protocols for in vitro culture are of great interest for their micropropagation and biotechnological breeding. We assessed the organogenesis response from leaf explants in four interspecific hybrids and in their parents testing two organogenic media: SIM-A, containing 6-benzylaminopurine and kinetin, and SIM-B, which contains thidiazuron. A higher regeneration capacity in the hybrids compared to their parents was observed. Whereas in interspecific hybrids and in one accession of S. melongena similar regeneration rates were observed for SIM-A and SIM-B, higher regeneration was found in the rest of genotypes when thidiazuron was used. Rooting ability in the interspecific hybrids was lower in in vitro micropropagated plants (35–60%) than in plants regenerated from explants (100%). The addition of indolbutiric acid (1 mg L−1) induced roots in nonrooted genotypes. In summary, we have adjusted in vitro culture conditions for regenerating and rooting S. melongena × S. aethiopicum hybrids. We have also demonstrated that these hybrids are heterotic for regeneration, which may be of interest for basic science studies. PMID:24592179

Genome-Wide Identification and Comparative Analysis of Conserved and Novel MicroRNAs in Grafted Watermelon by High-Throughput Sequencing

PubMed Central

Liu, Na; Yang, Jinghua; Guo, Shaogui; Xu, Yong; Zhang, Mingfang

2013-01-01

MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs involved in the post-transcriptional gene regulation and play a critical role in plant growth, development and stresses response. However less is known about miRNAs involvement in grafting behaviors, especially with the watermelon (Citrullus lanatus L.) crop, which is one of the most important agricultural crops worldwide. Grafting method is commonly used in watermelon production in attempts to improve its adaptation to abiotic and biotic stresses, in particular to the soil-borne fusarium wilt disease. In this study, Solexa sequencing has been used to discover small RNA populations and compare miRNAs on genome-wide scale in watermelon grafting system. A total of 11,458,476, 11,614,094 and 9,339,089 raw reads representing 2,957,751, 2,880,328 and 2,964,990 unique sequences were obtained from the scions of self-grafted watermelon and watermelon grafted on-to bottle gourd and squash at two true-leaf stage, respectively. 39 known miRNAs belonging to 30 miRNA families and 80 novel miRNAs were identified in our small RNA dataset. Compared with self-grafted watermelon, 20 (5 known miRNA families and 15 novel miRNAs) and 47 (17 known miRNA families and 30 novel miRNAs) miRNAs were expressed significantly different in watermelon grafted on to bottle gourd and squash, respectively. MiRNAs expressed differentially when watermelon was grafted onto different rootstocks, suggesting that miRNAs might play an important role in diverse biological and metabolic processes in watermelon and grafting may possibly by changing miRNAs expressions to regulate plant growth and development as well as adaptation to stresses. The small RNA transcriptomes obtained in this study provided insights into molecular aspects of miRNA-mediated regulation in grafted watermelon. Obviously, this result would provide a basis for further unravelling the mechanism on how miRNAs information is exchanged between scion and rootstock in grafted watermelon, and its relevance to diverse biological processes and environmental adaptation. PMID:23468976

The fertilization ability and developmental competence of bovine oocytes grown in vitro

PubMed Central

MAKITA, Miho; UEDA, Mayuko; MIYANO, Takashi

2016-01-01

In vitro growth culture systems for oocytes are being developed in several mammalian species. In these growth culture systems, in vitro grown oocytes usually have lower blastocyst formation than in vivo grown oocytes after in vitro fertilization. Furthermore, there have been a few reports that investigated the fertilization ability of in vitro grown oocytes in large animals. The purpose of this study was to investigate the fertilization process and developmental competence of bovine oocytes grown in vitro. Oocyte-granulosa cell complexes collected from bovine early antral follicles (0.4−0.7 mm in diameter) were cultured for growth with 17β-estradiol and androstenedione for 14 days and matured in vitro. These oocytes were then inseminated for 6 or 12 h, and further cultured for development up to 8 days in vitro. After growth culture, oocytes grew from 95 µm to around 120 µm and acquired maturation competence (79%). Although fertilization rates of in vitro grown oocytes were low after 6 h of insemination, 34% of in vitro grown oocytes fertilized normally after 12 h of insemination, having two polar bodies and two pronuclei with a sperm tail, and 22% of these oocytes developed into blastocysts after 8 days of culture. The fertilization and blastocyst formation rates were similar to those of in vivo grown oocytes. In addition, blastocyst cell numbers were also similar between in vitro and in vivo grown oocytes. In conclusion, in vitro grown bovine oocytes are similar to in vivo grown oocytes in fertilization ability and can develop into blastocysts. PMID:27151093

The fertilization ability and developmental competence of bovine oocytes grown in vitro.

PubMed

Makita, Miho; Ueda, Mayuko; Miyano, Takashi

2016-08-25

In vitro growth culture systems for oocytes are being developed in several mammalian species. In these growth culture systems, in vitro grown oocytes usually have lower blastocyst formation than in vivo grown oocytes after in vitro fertilization. Furthermore, there have been a few reports that investigated the fertilization ability of in vitro grown oocytes in large animals. The purpose of this study was to investigate the fertilization process and developmental competence of bovine oocytes grown in vitro. Oocyte-granulosa cell complexes collected from bovine early antral follicles (0.4-0.7 mm in diameter) were cultured for growth with 17β-estradiol and androstenedione for 14 days and matured in vitro. These oocytes were then inseminated for 6 or 12 h, and further cultured for development up to 8 days in vitro. After growth culture, oocytes grew from 95 µm to around 120 µm and acquired maturation competence (79%). Although fertilization rates of in vitro grown oocytes were low after 6 h of insemination, 34% of in vitro grown oocytes fertilized normally after 12 h of insemination, having two polar bodies and two pronuclei with a sperm tail, and 22% of these oocytes developed into blastocysts after 8 days of culture. The fertilization and blastocyst formation rates were similar to those of in vivo grown oocytes. In addition, blastocyst cell numbers were also similar between in vitro and in vivo grown oocytes. In conclusion, in vitro grown bovine oocytes are similar to in vivo grown oocytes in fertilization ability and can develop into blastocysts.

The bottle gourd genome provides insights into Cucurbitaceae evolution and facilitates mapping of a Papaya ringspot virus resistance locus

USDA-ARS?s Scientific Manuscript database

Bottle gourd (Lagenaria siceraria) is an important vegetable crop as well as a rootstock for other cucurbit crops. In this study, we report a high-quality 313.4-Mb genome sequence of a bottle gourd inbred line, USVL1VR-Ls, with a scaffold N50 of 8.7 Mb and the longest of 19.0 Mb. About 98.3% of the ...

Spectral quality may be used to alter plant disease development in CELSS

NASA Astrophysics Data System (ADS)

Schuerger, A. C.; Brown, C. S.

1994-11-01

Plants were grown under light emitting diode (LED) arrays with different spectral qualities to determine the effects of light on the development of tomato mosaic virus (ToMV) in peppers and powdery mildew on cucumbers. One LED array supplied 100% of the photosynthetic photon flux (PPF) at 660 nm, a second array supplied 90% of the PPF at 660 nm and 10% at 735 nm, and a third array supplied 98% of the PPF at 660 nm with 2% in the blue region (380-500 nm) supplied by blue fluorescent lamps. Control plants were grown under metal halide (MH) lamps. Pepper plants inoculated with ToMV and grown under 660 and 660/735 LED arrays showed marked increases in both the rate and the severity of symptoms as compared to inoculated plants grown under the MH lamp or 660/blue array. Pepper plants grown under the 660/blue array did not develop symptoms as rapidly as inoculated plants grown under the 660 or 660/735 arrays, but they did develop symptoms faster than inoculated plants grown under the MH lamp. The numbers of colonies of powdery mildew per leaf and the size of each colony were greatest on inoculated cucumber plants grown under the MH lamp.

Quantification and localization of hesperidin and rutin in Citrus sinensis grafted on C. limonia after Xylella fastidiosa infection by HPLC-UV and MALDI imaging mass spectrometry.

PubMed

Soares, Márcio Santos; da Silva, Danielle Fernandes; Forim, Moacir Rossi; da Silva, Maria Fátima das Graças Fernandes; Fernandes, João Batista; Vieira, Paulo Cezar; Silva, Denise Brentan; Lopes, Norberto Peporine; de Carvalho, Sérgio Alves; de Souza, Alessandra Alves; Machado, Marcos Antônio

2015-07-01

A high performance liquid chromatography-ultraviolet (HPLC-UV) method was developed for quantifying hesperidin and rutin levels in leaves and stems of Citrus limonia, with a good linearity over a range of 1.0-80.0 and 1.0-50.0 μg mL(-1) respectively, with r(2)>0.999 for all curves. The limits of detection (LOD) for both flavonoids were 0.6 and 0.5 μg mL(-1), respectively, with quantification (LOQ) being 2.0 and 1.0 μg mL(-1), respectively. The quantification method was applied to Citrus sinensis grafted onto C. limonia with and without CVC (citrus variegated chlorosis) symptoms after Xylella fastidiosa infection. The total content of rutin was low and practically constant in all analyses in comparison with hesperidin, which showed a significant increase in its amount in symptomatic leaves. Scanning electron microscopy studies on leaves with CVC symptoms showed vessel occlusion by biofilm, and a crystallized material was noted. Considering the difficulty in isolating these crystals for analysis, tissue sections were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) to confirm the presence of hesperidin at the site of infection. The images constructed from MS/MS data with a specific diagnostic fragment ion (m/z 483) also showed higher ion intensities for it in infected plants than in healthy ones, mainly in the vessel regions. These data suggest that hesperidin plays a role in the plant-pathogen interaction, probably as a phytoanticipin. This method was also applied to C. sinensis and C. limonia seedlings, and comparison with the graft results showed that the rootstock had an increased hesperidin content ∼3.6 fold greater in the graft stem than in the stem of C. sinensis seedlings. Increase in hesperidin content by rootstock can be related to induced internal defense mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization and regulation of the resistance-nodulation-cell division-type multidrug efflux pumps MdtABC and MdtUVW from the fire blight pathogen Erwinia amylovora.

PubMed

Pletzer, Daniel; Weingart, Helge

2014-07-11

The Gram-negative bacterium Erwinia amylovora is the causal agent of the devastating disease fire blight in rosaceous plants such as apple, pear, quince, raspberry, and cotoneaster. In order to survive and multiply in a host, microbes must be able to circumvent the toxic effects of antimicrobial plant compounds, such as flavonoids and tannins. E. amylovora uses multidrug efflux transporters that recognize and actively export toxic compounds out of the cells. Here, two heterotrimeric resistance-nodulation-cell division (RND)-type multidrug efflux pumps, MdtABC and MdtUVW, from E. amylovora were identified. These RND systems are unusual in that they contain two different RND proteins forming a functional pump. To find the substrate specificities of the two efflux systems, we overexpressed the transporters in a hypersensitive mutant lacking the major RND pump AcrB. Both transporters mediated resistance to several flavonoids, fusidic acid and novobiocin. Additionally, MdtABC mediated resistance towards josamycin, bile salts and silver nitrate, and MdtUVW towards clotrimazole. The ability of the mdtABC- and mdtUVW-deficient mutants to multiply in apple rootstock was reduced. Quantitative RT-PCR analyses revealed that the expression of the transporter genes was induced during infection of apple rootstock. The polyphenolic plant compound tannin, as well as the heavy metal salt tungstate was found to induce the expression of mdtABC. Finally, the expression of the mdtABC genes was shown to be regulated by BaeR, the response regulator of the two-component system BaeSR, a cell envelope stress response system that controls the adaptive responses to changes in the environment. The expression of MdtABC and MdtUVW is induced during growth of E. amylovora in planta. We identified the plant polyphenol tannin as inducer of mdtABC expression. The reduced ability of the mdtABC- and mdtUVW-deficient mutants to multiply in apple rootstock suggests that the efflux pumps are involved in resistance to plant antimicrobials, maybe including flavonoids, which were identified as substrates of both pumps. Furthermore, we found that the mdtABC operon belongs to the regulon of the two-component regulator BaeR suggesting a role of this RND transporter in the cell envelope stress response of E. amylovora.

Characterization and regulation of the Resistance-Nodulation-Cell Division-type multidrug efflux pumps MdtABC and MdtUVW from the fire blight pathogen Erwinia amylovora

PubMed Central

2014-01-01

Background The Gram-negative bacterium Erwinia amylovora is the causal agent of the devastating disease fire blight in rosaceous plants such as apple, pear, quince, raspberry, and cotoneaster. In order to survive and multiply in a host, microbes must be able to circumvent the toxic effects of antimicrobial plant compounds, such as flavonoids and tannins. E. amylovora uses multidrug efflux transporters that recognize and actively export toxic compounds out of the cells. Here, two heterotrimeric resistance-nodulation-cell division (RND)-type multidrug efflux pumps, MdtABC and MdtUVW, from E. amylovora were identified. These RND systems are unusual in that they contain two different RND proteins forming a functional pump. Results To find the substrate specificities of the two efflux systems, we overexpressed the transporters in a hypersensitive mutant lacking the major RND pump AcrB. Both transporters mediated resistance to several flavonoids, fusidic acid and novobiocin. Additionally, MdtABC mediated resistance towards josamycin, bile salts and silver nitrate, and MdtUVW towards clotrimazole. The ability of the mdtABC- and mdtUVW-deficient mutants to multiply in apple rootstock was reduced. Quantitative RT-PCR analyses revealed that the expression of the transporter genes was induced during infection of apple rootstock. The polyphenolic plant compound tannin, as well as the heavy metal salt tungstate was found to induce the expression of mdtABC. Finally, the expression of the mdtABC genes was shown to be regulated by BaeR, the response regulator of the two-component system BaeSR, a cell envelope stress response system that controls the adaptive responses to changes in the environment. Conclusions The expression of MdtABC and MdtUVW is induced during growth of E. amylovora in planta. We identified the plant polyphenol tannin as inducer of mdtABC expression. The reduced ability of the mdtABC- and mdtUVW-deficient mutants to multiply in apple rootstock suggests that the efflux pumps are involved in resistance to plant antimicrobials, maybe including flavonoids, which were identified as substrates of both pumps. Furthermore, we found that the mdtABC operon belongs to the regulon of the two-component regulator BaeR suggesting a role of this RND transporter in the cell envelope stress response of E. amylovora. PMID:25012600

Comparative Transcriptome Analysis Reveals a Preformed Defense System in Apple Root of a Resistant Genotype of G.935 in the Absence of Pathogen

PubMed Central

Shao, Jonathan; Zhou, Zhe; Davis, Robert E.

2017-01-01

Two apple rootstock genotypes G.935 and B.9 were recently demonstrated to exhibit distinct resistance responses following infection by Pythium ultimum. As part of an effort to elucidate the genetic regulation of apple root resistance to soilborne pathogens, preinoculation transcriptome variations in roots of these two apple rootstock genotypes are hypothesized to contribute to the observed disease resistance phenotypes. Results from current comparative transcriptome analysis demonstrated elevated transcript abundance for many genes which function in a system-wide defense response in the root tissue of the resistant genotype of G.935 in comparison with susceptible B.9. Based on the functional annotation, these differentially expressed genes encode proteins that function in several tiers of defense responses, such as pattern recognition receptors for pathogen detection and subsequent signal transduction, defense hormone biosynthesis and signaling, transcription factors with known roles in defense activation, enzymes of secondary metabolism, and various classes of resistance proteins. The data set suggested a more poised status, which is ready to defend pathogen infection, in the root tissues of resistant genotype of G.935, compared to the susceptible B.9. The significance of preformed defense in the absence of a pathogen toward overall resistance phenotypes in apple root and the potential fitness cost due to the overactivated defense system were discussed. PMID:28465679

Variation in Host and Pathogen in the Neonectria/Malus Interaction; toward an Understanding of the Genetic Basis of Resistance to European Canker

PubMed Central

Gómez-Cortecero, Antonio; Saville, Robert J.; Scheper, Reiny W. A.; Bowen, Joanna K.; Agripino De Medeiros, Hugo; Kingsnorth, Jennifer; Xu, Xiangming; Harrison, Richard J.

2016-01-01

Apple canker caused by the phytopathogenic fungus Neonectria ditissima is an economically important disease, which has spread in recent years to almost all pome-producing regions of the world. N. ditissima is able to cross-infect a wide range of apple varieties and causes branch and trunk lesions, known as cankers. Most modern apple varieties are susceptible and in extreme cases suffer from high mortality (up to 50%) in the early phase of orchard establishment. There is no known race structure of the pathogen and the global level of genetic diversity of the pathogen population is unknown. Resistance breeding is underway in many global breeding programmes, but nevertheless, a total resistance to canker has not yet been demonstrated. Here we present preliminary data from a survey of the phylogenetic relationships between global isolates of N. ditissima which reveals only slight evidence for population structure. In addition we report the results of four rapid screening tests to assess the response to N. ditissima in different apple scion and rootstock varieties, which reveals abundant variation in resistance responses in both cultivar and rootstock material. Further seedling tests show that the segregation patterns of resistance and susceptibility vary widely between crosses. We discuss inconsistencies in test performance with field observations and discuss future research opportunities in this area. PMID:27695463

Phylogenetic analysis of PR genes in some pome fruit species with the emphasis on transcriptional analysis and ROS response under Erwinia amylovora inoculation in apple.

PubMed

Hassani, Maryam; Salami, Seyed Alireza; Nasiri, Jaber; Abdollahi, Hamid; Ghahremani, Zahra

2016-02-01

Attempts were made to identify eight pathogenesis related (PR) genes (i.e., PR-1a, PR3-ch1, PR3-Ch2, PR3-Ch3, PR3-Ch4, PR3-Ch5, PR-5 and PR-8) from 27 genotypes of apple, quince and pear, which are induced in response to inoculation with the pathogen Erwinia amylovora, the causal agent of fire blight. Totally, 32 PR genes of different families were obtained, excepting PR3-Ch2 (amplified only in apple) and PR3-Ch4 (amplified only in apple and pear), the others were successfully amplified in all the genotypes of apple, quince and pear. Evolutionary, the genes of each family exhibited significant homology with each other, as the corresponded phylogenetic neighbor-joining-based dendrograms were taken into consideration. Meanwhile, according to the expression assay, it was deduced that the pathogen activity can significantly affect the expression levels of some selected PR genes of PR3-Ch2, PR3-Ch4, PR3-Ch5 and particularly Cat I in both resistant (MM-111) and semi-susceptible (MM-106) apple rootstocks. Lastly, it was concluded that the pathogen E. amylovora is able to stimulate ROS response, particularly using generation of hydrogen peroxide (H2O2) in both aforementioned apple rootstock.

Reduction in the critical dark length for flower induction during aging in the short-day plant Pharbitis nil var. Kidachi.

PubMed

Hasegawa, Hiroshi; Yamada, Mizuki; Iwase, Yuiko; Wada, Kaede C; Takeno, Kiyotoshi

2010-12-01

The stress-sensitive short-day plant Pharbitis nil var. Kidachi flowers under a 16-h light and 8-h dark regime and non-stress conditions when grown for long periods of time. Such flowering was found to occur from the third week, and the floral buds were formed from the eighth node of the main stem. When young plants were grafted onto aged plants, the scions were induced to flower early. This flower induction by grafting was more effective when older plants were used as rootstocks. Grafting experiments using a single leaf as a donor revealed that younger leaves are more responsive to flower induction, suggesting that this age-mediated flowering response is not induced by aging or senescence of individual leaves. Rather, the plant may obtain the ability to flower as the whole plant ages. Flowering does not occur under continuous light conditions. A night break given in the 8-h dark period inhibits flowering. These results suggest that 8-h dark conditions, which are normally considered to be long-day conditions, actually correspond to short-day conditions for this plant. The 8-h dark conditions caused early flowering more efficiently in older plants. The critical dark length determined by a single treatment was 12 h in 0-week-old plants and was reduced to 6 h in 2- and 4-week-old plants. These results suggest that the critical dark length becomes shorter when plants get older. The expression of PnFT1 and PnFT2, orthologs of the flowering gene flowering locus T, was analyzed by reverse transcription-polymerase chain reaction revealing that the expression of PnFT at the end of dark period is correlated with flowering.

Determination of diagnostic standards on saturated soil extracts for cut roses grown in greenhouses.

PubMed

Franco-Hermida, John Jairo; Quintero, María Fernanda; Cabrera, Raúl Iskander; Guzman, José Miguel

2017-01-01

This work comprises the theoretical determination and validation of diagnostic standards for the analysis of saturated soil extracts for cut rose flower crops (Rosa spp.) growing in the Bogota Plateau, Colombia. The data included 684 plant tissue analyses and 684 corresponding analyses of saturated soil extracts, all collected between January 2009 and June 2013. The tissue and soil samples were selected from 13 rose farms, and from cultivars grafted on the 'Natal Briar' rootstock. These concurrent samples of soil and plant tissues represented 251 production units (locations) of approximately 10,000 m2 distributed across the study area. The standards were conceived as a tool to improve the nutritional balance in the leaf tissue of rose plants and thereby define the norms for expressing optimum productive potential relative to nutritional conditions in the soil. To this end, previously determined diagnostic standard for rose leaf tissues were employed to obtain rates of foliar nutritional balance at each analyzed location and as criteria for determining the diagnostic norms for saturated soil extracts. Implementing this methodology to foliar analysis, showed a higher significant correlation for diagnostic indices. A similar behavior was observed in saturated soil extracts analysis, becoming a powerful tool for integrated nutritional diagnosis. Leaf analyses determine the most limiting nutrients for high yield and analyses of saturated soil extracts facilitate the possibility of correcting the fertigation formulations applied to soils or substrates. Recommendations are proposed to improve the balance in soil-plant system with which the possibility of yield increase becomes more probable. The main recommendations to increase and improve rose crop flower yields would be: continuously check pH values of SSE, reduce the amounts of P, Fe, Zn and Cu in fertigation solutions and carefully analyze the situation of Mn in the soil-plant system.

Development of a dense SNP-based linkage map of an apple rootstock progeny using the Malus Infinium whole genome genotyping array

PubMed Central

2012-01-01

Background A whole-genome genotyping array has previously been developed for Malus using SNP data from 28 Malus genotypes. This array offers the prospect of high throughput genotyping and linkage map development for any given Malus progeny. To test the applicability of the array for mapping in diverse Malus genotypes, we applied the array to the construction of a SNP-based linkage map of an apple rootstock progeny. Results Of the 7,867 Malus SNP markers on the array, 1,823 (23.2%) were heterozygous in one of the two parents of the progeny, 1,007 (12.8%) were heterozygous in both parental genotypes, whilst just 2.8% of the 921 Pyrus SNPs were heterozygous. A linkage map spanning 1,282.2 cM was produced comprising 2,272 SNP markers, 306 SSR markers and the S-locus. The length of the M432 linkage map was increased by 52.7 cM with the addition of the SNP markers, whilst marker density increased from 3.8 cM/marker to 0.5 cM/marker. Just three regions in excess of 10 cM remain where no markers were mapped. We compared the positions of the mapped SNP markers on the M432 map with their predicted positions on the ‘Golden Delicious’ genome sequence. A total of 311 markers (13.7% of all mapped markers) mapped to positions that conflicted with their predicted positions on the ‘Golden Delicious’ pseudo-chromosomes, indicating the presence of paralogous genomic regions or mis-assignments of genome sequence contigs during the assembly and anchoring of the genome sequence. Conclusions We incorporated data for the 2,272 SNP markers onto the map of the M432 progeny and have presented the most complete and saturated map of the full 17 linkage groups of M. pumila to date. The data were generated rapidly in a high-throughput semi-automated pipeline, permitting significant savings in time and cost over linkage map construction using microsatellites. The application of the array will permit linkage maps to be developed for QTL analyses in a cost-effective manner, and the identification of SNPs that have been assigned erroneous positions on the ‘Golden Delicious’ reference sequence will assist in the continued improvement of the genome sequence assembly for that variety. PMID:22631220

Influence of the Sting Nematode, Belonolaimus longicaudalus, on Young Citrus Trees.

PubMed

Kaplan, D T

1985-10-01

The sting nematode, Belonolaimus longicaudatus, was associated with poor growth of citrus in a central Florida nursery. Foliage of trees was sparse and chlorotic. Affected rootstocks included Changsha and Cleopatra mandarin orange; Flying Dragon, Rubidoux, and Jacobsen trifoliate orange; Macrophylla and Milam lemon; Palestine sweet lime; sour orange; and the hybrids - Carrizo, Morton, and Rusk citrange and Swingle citrumelo. Root symptoms included apical swelling, development of swollen terminals containing 3-5 apical meristems and hyperplastic tissue, coarse roots, and a reduction in the number of fibrous roots. Population densities as high as 392 sting nematodes per liter soil were detected, with 80% of the population occurring in the top 30 cm of soil; however, nematodes were detected to 107 cm deep. Although an ectoparasite, the nematode was closely associated with citrus root systems and was transported with bare root nursery stock. Disinfestation was accomplished by hot water treatment (49 C for 5 minutes).

Growth conditions and environmental factors impact aerosolization but not virulence of Francisella tularensis infection in mice

PubMed Central

Faith, Seth A.; Smith, Le'Kneitah P.; Swatland, Angela S.; Reed, Douglas S.

2012-01-01

In refining methodology to develop a mouse model for inhalation of Francisella tularensis, it was noted that both relative humidity and growth media impacted the aerosol concentration of the live vaccine strain (LVS) of F. tularensis. A relative humidity of less than 55% had a negative impact on the spray factor, the ratio between the concentration of LVS in the aerosol and the nebulizer. The spray factor was significantly higher for LVS grown in brain heart infusion (BHI) broth than LVS grown in Mueller–Hinton broth (MHb) or Chamberlain's chemically defined medium (CCDM). The variability between aerosol exposures was also considerably less with BHI. LVS grown in BHI survived desiccation far longer than MHb-grown or CCDM-grown LVS (~70% at 20 min for BHI compared to <50% for MHb and CCDM). Removal of the capsule by hypertonic treatment impacted the spray factor for CCDM-grown LVS or MHb-grown LVS but not BHI-grown LVS, suggesting the choice of culture media altered the adherence of the capsule to the cell membrane. The choice of growth media did not impact the LD50 of LVS but the LD99 of BHI-grown LVS was 1 log lower than that for MHb-grown LVS or CCDM-grown LVS. Splenomegaly was prominent in mice that succumbed to MHb- and BHI-grown LVS but not CCDM-grown LVS. Environmental factors and growth conditions should be evaluated when developing new animal models for aerosol infection, particularly for vegetative bacterial pathogens. PMID:23087911

A genome-wide expression profile of salt-responsive genes in the apple rootstock Malus zumi.

PubMed

Li, Qingtian; Liu, Jia; Tan, Dunxian; Allan, Andrew C; Jiang, Yuzhuang; Xu, Xuefeng; Han, Zhenhai; Kong, Jin

2013-10-18

In some areas of cultivation, a lack of salt tolerance severely affects plant productivity. Apple, Malus x domestica Borkh., is sensitive to salt, and, as a perennial woody plant the mechanism of salt stress adaption will be different from that of annual herbal model plants, such as Arabidopsis. Malus zumi is a salt tolerant apple rootstock, which survives high salinity (up to 0.6% NaCl). To examine the mechanism underlying this tolerance, a genome-wide expression analysis was performed, using a cDNA library constructed from salt-treated seedlings of Malus zumi. A total of 15,000 cDNA clones were selected for microarray analysis. In total a group of 576 cDNAs, of which expression changed more than four-fold, were sequenced and 18 genes were selected to verify their expression pattern under salt stress by semi-quantitative RT-PCR. Our genome-wide expression analysis resulted in the isolation of 50 novel Malus genes and the elucidation of a new apple-specific mechanism of salt tolerance, including the stabilization of photosynthesis under stress, involvement of phenolic compounds, and sorbitol in ROS scavenging and osmoprotection. The promoter regions of 111 genes were analyzed by PlantCARE, suggesting an intensive cross-talking of abiotic stress in Malus zumi. An interaction network of salt responsive genes was constructed and molecular regulatory pathways of apple were deduced. Our research will contribute to gene function analysis and further the understanding of salt-tolerance mechanisms in fruit trees.

A Genome-Wide Expression Profile of Salt-Responsive Genes in the Apple Rootstock Malus zumi

PubMed Central

Li, Qingtian; Liu, Jia; Tan, Dunxian; Allan, Andrew C.; Jiang, Yuzhuang; Xu, Xuefeng; Han, Zhenhai; Kong, Jin

2013-01-01

In some areas of cultivation, a lack of salt tolerance severely affects plant productivity. Apple, Malus x domestica Borkh., is sensitive to salt, and, as a perennial woody plant the mechanism of salt stress adaption will be different from that of annual herbal model plants, such as Arabidopsis. Malus zumi is a salt tolerant apple rootstock, which survives high salinity (up to 0.6% NaCl). To examine the mechanism underlying this tolerance, a genome-wide expression analysis was performed, using a cDNA library constructed from salt-treated seedlings of Malus zumi. A total of 15,000 cDNA clones were selected for microarray analysis. In total a group of 576 cDNAs, of which expression changed more than four-fold, were sequenced and 18 genes were selected to verify their expression pattern under salt stress by semi-quantitative RT-PCR. Our genome-wide expression analysis resulted in the isolation of 50 novel Malus genes and the elucidation of a new apple-specific mechanism of salt tolerance, including the stabilization of photosynthesis under stress, involvement of phenolic compounds, and sorbitol in ROS scavenging and osmoprotection. The promoter regions of 111 genes were analyzed by PlantCARE, suggesting an intensive cross-talking of abiotic stress in Malus zumi. An interaction network of salt responsive genes was constructed and molecular regulatory pathways of apple were deduced. Our research will contribute to gene function analysis and further the understanding of salt-tolerance mechanisms in fruit trees. PMID:24145753

Incidence and epidemiology of Citrus tristeza virus in the Valencian community of Spain.

PubMed

Cambra, M; Gorris, M T; Marroquín, C; Román, M P; Olmos, A; Martínez, M C; de Mendoza, A H; López, A; Navarro, L

2000-11-01

The first outbreak of citrus tristeza disease in Spain caused by Citrus tristeza virus (CTV) was recorded in 1957 in the Valencian Community (VC). In total c. 40 million trees, mainly of sweet orange and mandarin grafted on sour orange rootstocks, declined due to CTV. Large-scale surveys in different municipalities of the VC indicated that the disease spread very fast. Incidence increased from 11% in 1989 to 53% in 1998. Toxoptera aurantii and Aphis spiraecola (inefficient aphid vectors of CTV) predominated before 1985-87. Since then the relatively efficient vector Aphis gossypii has become dominant and induced an epidemic that has been modelled. The large number of A.gossypii that visited each clementine tree (estimated to exceed 97000 per year) explained the difference between the temporal pattern of spread of CTV in clementine which followed the Gompertz model and that in sweet orange (logistic model). The susceptibility of the different citrus species to CTV infection by aphids seems to depend on the number of young, succulent shoots produced. The epidemiological data allowed specific recommendations to be made to growers in order to facilitate a change to a modern citrus industry based on the use of selected varieties grafted on tristeza-tolerant rootstocks produced within a certification scheme. This has been done already in almost 90% of the VC citrus-growing area. The tristeza problem has been solved unless more aggressive isolates are introduced and become prevalent.

[Graft hybridization and the specificity of heredity in fruit trees].

PubMed

Liu, Yong-Sheng; Li, Bao-Yin; Li, Gui-Rong; Zhou, Xiu-Mei

2004-09-01

Emphatically discusses the relationship between graft hybridization and the specificity of heredity in fruit trees on the basis of introducing the recent achievements in plant graft hybridization. We propose that genetic materials in rootstock being translocated and integrated into the genome of the germ cells and embryonic cells in scion are the main reasons why the majority of the hybrid seedlings have wild properties and the heredity of fruit trees violate Mendel's laws of heredity. The potential of graft hybridization in fruit breeding are also discussed.

Quantitative expression patterns of GDF9 and BMP15 genes in sheep ovarian follicles grown in vivo or cultured in vitro.

PubMed

Kona, S S R; Praveen Chakravarthi, V; Siva Kumar, A V N; Srividya, D; Padmaja, K; Rao, V H

2016-01-15

Quantitative patterns of expression of the growth differentiation factor 9 (GDF9) and bone morphogenic protein 15 (BMP15) genes in different development stages of in vivo and in vitro grown ovarian follicles in sheep were studied for the first time. Both GDF9 and BMP15 were expressed in the cumulus cells and oocytes at all the development stages of in vivo and in vitro grown ovarian follicles. Growth differentiation factor 9 and bone morphogenic protein 15 exhibited stage-specific undulations in the expression in the cumulus cells and oocytes isolated from in vivo grown ovarian follicles. These undulations could be related to discrete development events during the ovarian follicle development. The expression of GDF9 and BMP15 was highest (3.38 ± 0.02 and 2.69 ± 0.06, respectively; P ≤ 0.05) in the primordial follicles compared with preantral, early antral, antral, and large antral stages. Similarly, GDF9 and BMP15 expression in the cumulus cells (0 ± 0.16 and 0 ± 0.07) and oocytes (1.47 ± 0.07 and 1.32 ± 0.03) was lowest (P ≤ 0.05) in the in vivo grown antral follicles. In the cultured follicles, the stage-specific undulations observed in the expression of GDF9 and BMP15 in the in vivo grown follicles were either different or abolished. For example, in the oocytes from in vitro grown follicles, the expression of BMP15 did not change as the development progressed all the way from preantral to large antral follicle stage although in the oocytes from in vivo grown follicles BMP15 expression exhibited stage-specific variations. It is concluded that GDF9 and BMP15 follow a stage-specific pattern of expression during the in vivo development of ovarian follicles in sheep, and in vitro culture altered the stage-specific changes in the expression of these two genes. Copyright © 2016 Elsevier Inc. All rights reserved.

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.

Detection of a New Luteovirus in Imported Nectarine Trees: A Case Study to Propose Adoption of Metagenomics in Post-Entry Quarantine.

PubMed

Bag, Sudeep; Al Rwahnih, Maher; Li, Ashley; Gonzalez, Asaul; Rowhani, Adib; Uyemoto, Jerry K; Sudarshana, Mysore R

2015-06-01

In spring 2013, 5-year-old nectarine (Prunus persica) trees, grafted on peach rootstock Nemaguard, were found stunted in a propagation block in California. These trees had been propagated from budwood of three nectarine cultivars imported from France and cleared through the post-entry quarantine procedure. Examination of the canopy failed to reveal any obvious symptoms. However, examination of the trunks, after stripping the bark, revealed extensive pitting on the woody cylinder. To investigate the etiological agent, double-stranded RNA was extracted from bark scrapings from the scion and rootstock portions, and a cDNA library was prepared and sequenced using the Illumina platform. BLAST analysis of the contigs generated by the de novo assembly of sequence reads indicated the presence of a novel luteovirus. Complete sequence of the viral genome was determined by sequencing of three overlapping cDNA clones generated by reverse transcription-polymerase chain reaction (RT-PCR) and by rapid amplification of the 5'- and 3'-termini. The virus genome was comprised of 4,991 nucleotides with a gene organization similar to members of the genus Luteovirus (family Luteoviridae). The presence of the virus, tentatively named Nectarine stem pitting-associated virus, was confirmed in symptomatic trees by RT-PCR. Discovery of a new virus in nectarine trees after post-entry quarantine indicates the importance of including (i) metagenomic analysis by next-generation sequencing approach as an essential tool to assess the plant health status, and (ii) examination of the woody cylinders as part of the indexing process.

Cadmium stress antioxidant responses and root-to-shoot communication in grafted tomato plants.

PubMed

Gratão, Priscila Lupino; Monteiro, Carolina Cristina; Tezotto, Tiago; Carvalho, Rogério Falleiros; Alves, Letícia Rodrigues; Peters, Leila Priscila; Azevedo, Ricardo Antunes

2015-10-01

Many aspects related to ROS modulation of signaling networks and biological processes that control stress responses still remain unanswered. For this purpose, the grafting technique may be a powerful tool to investigate stress signaling and specific responses between plant organs during stress. In order to gain new insights on the modulation of antioxidant stress responses mechanisms, gas-exchange measurements, lipid peroxidation, H2O2 content, proline, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), ascorbate peroxidase (APX) and guaiacol peroxidase (GPOX) were analyzed in Micro-Tom grafted plants submitted to cadmium (Cd). The results observed revealed that higher amounts of Cd accumulated mainly in the roots and rootstocks when compared to leaves and scions. Macronutrients uptake (Ca, S, P and Mg) decreased in non-grafted plants, but differed among plant parts in all grafted plants. The results showed that the accumulation of proline observed in scions of grafted plants could be associated to the lower MDA contents in the scions of grafted plants. In the presence of Cd, non-grafted plants displayed increased CAT, GR, GPOX and APX activities for both tissues, whilst grafted plants revealed distinct trends that clearly indicate signaling responses from the rootstocks, allowing sufficient time to activate defense mechanisms in shoot. The information available concerning plants subjected to grafting can provide a better understanding of the mechanisms of Cd detoxification involving root-to-shoot signaling, opening new possibilities on strategies which can be used to manipulate heavy metal tolerance, since antioxidant systems are directly involved in such mechanism.

Melatonin enhances root regeneration, photosynthetic pigments, biomass, total carbohydrates and proline content in the cherry rootstock PHL-C (Prunus avium × Prunus cerasus).

PubMed

Sarropoulou, Virginia; Dimassi-Theriou, Kortessa; Therios, Ioannis; Koukourikou-Petridou, Magdalene

2012-12-01

The present study, investigates the effects of melatonin (0, 0.05, 0.1, 0.5, 1, 5 and 10 μM) on the morphogenic and biochemical responses in the cherry rootstock PHL-C (Prunus avium L. × Prunus cerasus L.), from shoot tip explants. The incorporation of melatonin (0-10 μM) in the Murashige and Skoog (MS) medium, greatly influenced rooting either positively or negatively. Melatonin, irrespective of its concentration, had a negative effect concerning the number of roots. However, application of 0.5 μM melatonin significantly increased the root length; while 1 μM melatonin increased the root length by 2.5 times, and the fresh weight of the roots by 4 times, in comparison to the control. Although 0.05 μM melatonin increased rooting by 11.11%, 5 μM melatonin had a significant reduction on the number, the fresh weight of roots, and the rooting percentage. Melatonin concentration of 0.1 μM resulted in the greatest chlorophyll (a + b) content, and 5-10 μM reduced the chlorophyll concentration by 2 times, compared to the control. The high melatonin concentrations (5 and 10 μM), increased the levels of proline and carbohydrates in leaves by 3-4 times. In the roots, 0.5 μM of melatonin concentration increased the carbohydrate levels by 1.5 times, while 0.05, 0.1 and 1 μM melatonin concentration significantly reduced the proline content. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Branching in Pea (Action of Genes Rms3 and Rms4).

PubMed Central

Beveridge, C. A.; Ross, J. J.; Murfet, I. C.

1996-01-01

The nonallelic ramosus mutations rms3-2 and rms4 of pea (Pisum sativum L.) cause extensive release of vegetative axillary buds and lateral growth in comparison with wild-type (cv Torsdag) plants, in which axillary buds are not normally released under the conditions utilized. Grafting studies showed that the expression of the rms4 mutation in the shoot is independent of the genotype of the root-stock. In contrast, the length of the branches at certain nodes of rms3-2 plants was reduced by grafting to wild-type stocks, indicating that the wild-type Rms3 gene may control the level of a mobile substance produced in the root. This substance also appears to be produced in the shoot because Rms3 shoots did not branch when grafted to mutant rms3-2 rootstocks. However, the end product of the Rms3 gene appears to differ from that of the Rms2 gene (C.A. Beveridge, J.J. Ross, and I.C. Murfet [1994] Plant Physiol 104: 953-959) because reciprocal grafts between rms3-2 and rms2 seedlings produced mature shoots with apical dominance similar to that of rms3-2 and rms2 shoots grafted to wild-type stocks. Indole-3-acetic acid levels were not reduced in apical or nodal portions of rms4 plants and were actually elevated (up to 2-fold) in rms3-2 plants. It is suggested that further studies with these branching mutants may enable significant progress in understanding the normal control of apical dominance and the related communication between the root and shoot. PMID:12226224

Cryobiotechnology of apple (Malus spp.): development, progress and future prospects.

PubMed

Wang, Min-Rui; Chen, Long; Teixeira da Silva, Jaime A; Volk, Gayle M; Wang, Qiao-Chun

2018-05-01

Cryopreservation provides valuable genes for further breeding of elite cultivars, and cryotherapy improves the production of virus-free plants in Malus spp., thus assisting the sustainable development of the apple industry. Apple (Malus spp.) is one of the most economically important temperate fruit crops. Wild Malus genetic resources and existing cultivars provide valuable genes for breeding new elite cultivars and rootstocks through traditional and biotechnological breeding programs. These valuable genes include those resistant to abiotic factors such as drought and salinity, and to biotic factors such as fungi, bacteria and aphids. Over the last three decades, great progress has been made in apple cryobiology, making Malus one of the most extensively studied plant genera with respect to cryopreservation. Explants such as pollen, seeds, in vivo dormant buds, and in vitro shoot tips have all been successfully cryopreserved, and large Malus cryobanks have been established. Cryotherapy has been used for virus eradication, to obtain virus-free apple plants. Cryopreservation provided valuable genes for further breeding of elite cultivars, and cryotherapy improved the production of virus-free plants in Malus spp., thus assisting the sustainable development of the apple industry. This review provides updated and comprehensive information on the development and progress of apple cryopreservation and cryotherapy. Future research will reveal new applications and uses for apple cryopreservation and cryotherapy.

Genetic Map of Mango: A Tool for Mango Breeding

PubMed Central

Kuhn, David N.; Bally, Ian S. E.; Dillon, Natalie L.; Innes, David; Groh, Amy M.; Rahaman, Jordon; Ophir, Ron; Cohen, Yuval; Sherman, Amir

2017-01-01

Mango (Mangifera indica) is an economically and nutritionally important tropical/subtropical tree fruit crop. Most of the current commercial cultivars are selections rather than the products of breeding programs. To improve the efficiency of mango breeding, molecular markers have been used to create a consensus genetic map that identifies all 20 linkage groups in seven mapping populations. Polyembryony is an important mango trait, used for clonal propagation of cultivars and rootstocks. In polyembryonic mango cultivars, in addition to a zygotic embryo, several apomictic embryos develop from maternal tissue surrounding the fertilized egg cell. This trait has been associated with linkage group 8 in our consensus genetic map and has been validated in two of the seven mapping populations. In addition, we have observed a significant association between trait and single nucleotide polymorphism (SNP) markers for the vegetative trait of branch habit and the fruit traits of bloom, ground skin color, blush intensity, beak shape, and pulp color. PMID:28473837

Transformation of pecan and regeneration of transgenic plants.

PubMed

McGranahan, G H; Leslie, C A; Dandekar, A M; Uratsu, S L; Yates, I E

1993-09-01

A gene transfer system developed for walnut (Juglans regia L.) was successfully applied to pecan (Carya illinoensis [Wang] K. Koch). Repetitively embryogenic somatic embryos derived from open-pollinated seed of 'Elliott', 'Wichita', and 'Schley' were co-cultivated with Agrobacterium strain EHA 101/pCGN 7001, which contains marker genes for beta-glucuronidase activity and resistance to kanamycin. Several modifications of the standard walnut transformation techniques were tested, including a lower concentration of kanamycin and a modified induction medium, but these treatments had no measurable effect on efficiency of transformation. Nineteen of the 764 viable inoculated embryos produced transgenic subclones; 13 of these were from the line 'Elliott'6, 3 from 'Schley'5/3, and 3 from 'Wichita'9. Transgenic embryos of 'Wichita'9 germinated most readily and three subclones were successfully micropropagated. Three transgenic plants of one of these subclones were obtained by grafting the tissue cultured shoots to seedling pecan rootstock in the greenhouse. Gene insertion, initially detected by GUS activity, was confirmed by detection of integrated T-DNA sequences using Southern analysis.

Intergeneric somatic hybrid plants of Citrus sinensis cv. Hamlin and Poncirus trifoliata cv. Flying Dragon.

PubMed

Grosser, J W; Gmitter, F G; Chandler, J L

1988-01-01

Intergeneric somatic hybrid plants between 'Hamlin' sweet orange [Citrus sinensis (L.) Osbeck] and 'Flying Dragon' trifoliate orange (Poncirus trifoliata Raf.) were regenerated following protoplast fusion. 'Hamlin' protoplasts, isolated from an habituated embryogenic suspension culture, were fused chemically with 'Flying Dragon' protoplasts isolated from juvenile leaf tissue. The hybrid selection scheme was based on complementation of the regenerative ability of the 'Hamlin' protoplasts with the subsequent expression of the trifoliate leaf character of 'Flying Dragon.' Hybrid plants were regenerated via somatic embryogenesis and multiplied organogenically. Hybrid morphology was intermediate to that of the parents. Chromosome counts indicated that the hybrids were allotetraploids (2n=4x=36). Malate dehydrogenase (MDH) isozyme patterns confirmed the hybrid nature of the regenerated plants. These genetically unique somatic hybrid plants will be evaluated for citrus rootstock potential. The cell fusion, selection, and regeneration scheme developed herein should provide a general means to expand the germplasm base of cultivated Citrus by intergeneric hybridization with related sexually incompatible genera.

Agrometeorological models for forecasting the qualitative attributes of "Valência" oranges

NASA Astrophysics Data System (ADS)

Moreto, Victor Brunini; Rolim, Glauco de Souza; Zacarin, Bruno Gustavo; Vanin, Ana Paula; de Souza, Leone Maia; Latado, Rodrigo Rocha

2017-11-01

Forecasting is the act of predicting unknown future events using available data. Estimating, in contrast, uses data to simulate an actual condition. Brazil is the world's largest producer of oranges, and the state of São Paulo is the largest producer in Brazil. The "Valência" orange is among the most common cultivars in the state. We analyzed the influence of monthly meteorological variables during the growth cycle of Valência oranges grafted onto "Rangpur" lime rootstocks (VACR) for São Paulo, and developed monthly agrometeorological models for forecasting the qualitative attributes of VACR in mature orchard. For fruits per box for all months, the best accuracy was of 0.84 % and the minimum forecast range of 4 months. For the relation between °brix and juice acidity (RATIO) the best accuracy was of 0.69 % and the minimum forecast range of 5 months. Minimum, mean and maximum air temperatures, and relative evapotranspiration were the most important variables in the models.

Effects of future climate change on grape and wine quality: a case study for the Aglianico grape, Campania. Italy.

NASA Astrophysics Data System (ADS)

Bonfante, Antonello; Gambuti, Angelita; Monaco, Eugenia; Langella, Giuliano; Manna, Piero; Orefice, Nadia; Albrizio, Rossella; Basile, Angelo; Terribile, Fabio

2016-04-01

Water deficits limit yields and this is one of the negative aspects of climate change. However, this applies particularly when emphasis is on biomass production (e.g. for crops like maize, wheat, etc.) but not for plants where quality, not quantity is most relevant. For example, water stress occurring during specific phenological phases of grapevine development is an important factor when producing good quality wines. It induces, for example, the production of anthocyanins and aroma precursors. Water stress due to future increases of temperature and decreases of rainfall due to climate change can, therefore, represent an opportunity to increase winegrowers' incomes. This study was carried out in Campania region (Southern Italy), an area well known for high quality wine production. Growth of the Aglianico grapevine cultivar, with a standard clone population on 1103 Paulsen rootstocks, was studied on two different types of soil: Calcisols and Cambisols occurring along a slope of 90 m length with 11% gradient. The agro-hydrological model SWAP was calibrated and applied to estimate soil-plant water status at the various crop phenological phases for three vintages (2011-2013). Then, the Crop water stress index (CWSI), as estimated by the model, was related to physiological measurements (e.g. leaf water potential), grape bunches measurements (e.g. sugar content) and wine quality (e.g. tannins). For both soils, the correlation between measurements and CWSI were high (e.g. -0.97** with sugar; 0.895* with anthocyanins in the skins). Next, the model was applied to future climate conditions (2021-2051) obtained from statistical downscaling of Global Circulation Models (AOGCM) in order to estimate the effect of the climate on CWSI and hence on vine quality. Results show that the effects of climate change on grape and wine quality are not expected to be significant for this particular grape variety when grown on these Calcisols and Cambisols. However, significant differences are found between the two soils in terms of ultra, standard and low quality grapes, which confirms the reliability of the terroir concept for the Calcisol. CWSI >15 values for the Calcisol indicate the potential benefits of drip irrigation which is, however, not allowed under current regulations.

Human respiratory syncytial virus Memphis 37 grown in HEp-2 cells causes more severe disease in lambs than virus grown in vero cells

USDA-ARS?s Scientific Manuscript database

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in infants and young children. A small percentage of these individuals develop severe and even fatal disease. To better understand the pathogenesis of severe disease and develop therapies unique to the less-developed infan...

Determination of diagnostic standards on saturated soil extracts for cut roses grown in greenhouses

PubMed Central

Cabrera, Raúl Iskander

2017-01-01

This work comprises the theoretical determination and validation of diagnostic standards for the analysis of saturated soil extracts for cut rose flower crops (Rosa spp.) growing in the Bogota Plateau, Colombia. The data included 684 plant tissue analyses and 684 corresponding analyses of saturated soil extracts, all collected between January 2009 and June 2013. The tissue and soil samples were selected from 13 rose farms, and from cultivars grafted on the 'Natal Briar' rootstock. These concurrent samples of soil and plant tissues represented 251 production units (locations) of approximately 10,000 m2 distributed across the study area. The standards were conceived as a tool to improve the nutritional balance in the leaf tissue of rose plants and thereby define the norms for expressing optimum productive potential relative to nutritional conditions in the soil. To this end, previously determined diagnostic standard for rose leaf tissues were employed to obtain rates of foliar nutritional balance at each analyzed location and as criteria for determining the diagnostic norms for saturated soil extracts. Implementing this methodology to foliar analysis, showed a higher significant correlation for diagnostic indices. A similar behavior was observed in saturated soil extracts analysis, becoming a powerful tool for integrated nutritional diagnosis. Leaf analyses determine the most limiting nutrients for high yield and analyses of saturated soil extracts facilitate the possibility of correcting the fertigation formulations applied to soils or substrates. Recommendations are proposed to improve the balance in soil-plant system with which the possibility of yield increase becomes more probable. The main recommendations to increase and improve rose crop flower yields would be: continuously check pH values of SSE, reduce the amounts of P, Fe, Zn and Cu in fertigation solutions and carefully analyze the situation of Mn in the soil-plant system. PMID:28542547

Piceid (resveratrol glucoside) synthesis in stilbene synthase transgenic apple fruit.

PubMed

Rühmann, Susanne; Treutter, Dieter; Fritsche, Steffi; Briviba, Karlis; Szankowski, Iris

2006-06-28

A stilbene synthase gene along with the selectable marker gene bar for herbicide resistance was transferred via Agrobacterium tumefaciens mediated transformation into apple (Malus domesticaBorkh.) cvs. 'Elstar' and 'Holsteiner Cox'. The stilbene synthase catalyzes the conversion of 1 molecule of p-coumaroyl-CoA and 3 molecules of malonyl-CoA into 3,4',5-trihydroxystilbene, commonly known as resveratrol. This phytoalexin has implications in both phytopathology and human health. Greenhouse-grown transgenic and nontransformed control plants were grafted onto dwarfing rootstock M27. Flowering and fruiting occurred within the following years, offering the opportunity to analyze transgenic apple fruit and fertility of transgenic plants as well as inheritance of the transgenes into the seedling progeny. Molecular analysis revealed that the stilbene synthase is expressed in transgenic plants and in the skin and flesh of transgenic apple fruit. After formation, resveratrol is modified by the addition of a hexose sugar. The resulting component was characterized as piceid. With the aim of characterizing the influence of the novel biosynthetic pathway on the accumulation of other phenolic compounds naturally present in apple fruit, the amounts of flavanols, flavonols, phloretin derivatives and hydroxycinnamic acids in wild type and transgenic fruit were determined by HPLC. In all investigated transformed lines that accumulated piceid, no negative correlation between levels of piceid and the above-mentioned compounds was observed, except for the flavonol contents, which slightly decreased. Inheritance of the transgenes was confirmed in the seedling progeny, which were obtained after pollination of transgenic plants with nontransgenic pollen and vice versa after pollination of nontransgenic plants with pollen obtained from transgenic plants. The fertility of stilbene synthase transgenic plants was demonstrated. To the authors' knowledge this is the first time that data are available on piceid synthesis in transgenic apple fruit and the effects of its accumulation on levels of other phenolic compounds present in the fruit.

Light reflected from colored mulches affects aroma and phenol content of sweet basil (Ocimum basilicum L.) leaves.

PubMed

Loughrin, J H; Kasperbauer, M J

2001-03-01

Basil (Ocimum basilicum L.) is an herb the leaves of which are used to add a distinct aroma and flavor to food. It was hypothesized that the size and chemical composition of sun-grown basil leaves could be influenced by the color of light reflected from the soil surface and by the action of the reflected light through the natural growth regulatory system within the growing plants. Leaf morphology, aroma compounds, and soluble phenolics were compared in basil that had been grown over six colors of polyethylene row covers. Altering the ratios of blue, red, and far-red light reflected to growing plants influenced both leaf morphology and chemistry. Leaves developing over red surfaces had greater area, moisture percentage (succulence), and fresh weight than those developing over black surfaces. Basil grown over yellow and green surfaces produced significantly higher concentrations of aroma compounds than did basil grown over white and blue covers. Leaves grown over yellow and green mulches also contained significantly higher concentrations of phenolics than those grown over the other colors. Clearly, the wavelengths (color) of light reflected to growing basil plants affected leaf size, aroma, and concentrations of soluble phenolics, some of which are antioxidants.

Reproductive Ontogeny of Wheat Grown on the MIR Space Station

NASA Technical Reports Server (NTRS)

Bubenheim, David L.; Stieber, Joseph

1997-01-01

The reproductive ontogeny of 'Super-Dwarf' wheat grown on the space station Mir is chronicled from the vegetative phase through flower development. Changes in the apical meristem associated with transition From the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super Dwarf' wheat up to the point of anthesis. Filament elongation, which characteristically occurs just prior to anthesis and moves the anthers through the stigmatic branches thus facilitating pollination, did no1 xcur in the flowers of spikes grown on Mir. While development of spikes on tillers typically occurs later :han that of spikes on the main stem, all flowers appear to be arrested at the same developmental point.

Spectral quality affects disease development of three pathogens on hydroponically grown plants.

PubMed

Schuerger, A C; Brown, C S

1997-02-01

Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the effects of spectral quality on disease development when other wavelengths were included in the light source (MH-, 660/BF-, and 660/735-grown plants) were equivocal. These results demonstrate that spectral quality may be useful as a component of an integrated pest management program for future space-based controlled ecological life support systems.

Spectral quality affects disease development of three pathogens on hydroponically grown plants

NASA Technical Reports Server (NTRS)

Schuerger, A. C.; Brown, C. S.; Sager, J. C. (Principal Investigator)

1997-01-01

Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the effects of spectral quality on disease development when other wavelengths were included in the light source (MH-, 660/BF-, and 660/735-grown plants) were equivocal. These results demonstrate that spectral quality may be useful as a component of an integrated pest management program for future space-based controlled ecological life support systems.

Ectomycorrhizal Colonization of Container-Grown Northern Red Oak as Affected by Fertility

Treesearch

John L. Ruehle

1980-01-01

Abstract - The effects of different fertility regimes on Pisolithus tinctorius ectomycorrhizal development on northern red oak grown in containers was tested in the greenhouse. Artificial infestation of a milled pine bark-sewage sludge growing medium produced the best ectomycorrhizal development (63 percent) when a nutrient solution with 100pg/ml N...

CO2 and chamber effects on epidermal development in field grown peanut (Arachis hypogaea L.)

USDA-ARS?s Scientific Manuscript database

Peanut, (Arachis hypogaea L.) cvar. C76–16, was grown either in the field, or in open gas exchange chambers under elevated or ambient CO2 concentrations. Stomatal density and other selected epidermal parameters associated with leaf development and gas exchange were measured on recently fully expande...

Tetraploidy Enhances Boron-Excess Tolerance in Carrizo Citrange (Citrus sinensis L. Osb. × Poncirus trifoliata L. Raf.).

PubMed

Ruiz, Marta; Quiñones, Ana; Martínez-Alcántara, Belén; Aleza, Pablo; Morillon, Raphaël; Navarro, Luis; Primo-Millo, Eduardo; Martínez-Cuenca, Mary-Rus

2016-01-01

Tetraploidy modifies root anatomy which may lead to differentiated capacity to uptake and transport mineral elements. This work provides insights into physiological and molecular characters involved in boron (B) toxicity responses in diploid (2x) and tetraploid (4x) plants of Carrizo citrange (Citrus sinensis L. Osb. × Poncirus trifoliata L. Raf.), a widely used citrus rootstock. With B excess, 2x plants accumulated more B in leaves than 4x plants, which accounted for their higher B uptake and root-to-shoot transport rates. Ploidy did not modify the expression of membrane transporters NIP5 and BOR1 in roots. The cellular allocation of B excess differed between ploidy levels in the soluble fraction, which was lower in 4x leaves, while cell wall-linked B was similar in 2x and 4x genotypes. This correlates with the increased damage and stunted growth recorded in the 2x plants. The 4x roots were found to have fewer root tips, shorter specific root length, longer diameter, thicker exodermis and earlier tissue maturation in root tips, where the Casparian strip was detected at a shorter distance from the root apex than in the 2x roots. The results presented herein suggest that the root anatomical characters of the 4x plants play a key role in their lower B uptake capacity and root-to-shoot transport. Tetraploidy enhances B excess tolerance in citrange CarrizoExpression of NIP5 and BOR1 transporters and cell wall-bounded B are similar between ploidiesB tolerance is attributed to root anatomical modifications induced by genome duplicationThe rootstock 4x citrange carrizo may prevent citrus trees from B excess.

iTRAQ-Based Proteomic Analysis Reveals Potential Regulation Networks of IBA-Induced Adventitious Root Formation in Apple

PubMed Central

Lei, Chao; Fan, Sheng; Li, Ke; Meng, Yuan; Mao, Jiangping; Han, Mingyu; Zhao, Caiping; Bao, Lu; Zhang, Dong

2018-01-01

Adventitious root (AR) formation, which is controlled by endogenous and environmental factors, is indispensable for vegetative asexual propagation. However, comprehensive proteomic data on AR formation are still lacking. The aim of this work was to study indole-3-butyric acid (IBA)-induced AR formation in the dwarf apple rootstock ‘T337’. In this study, the effect of IBA on AR formation was analysed. Subsequent to treatment with IBA, both the rooting rate and root length of ‘T337’ increased significantly. An assessment of hormone levels in basal stem cuttings suggested that auxin, abscisic acid, and brassinolide were higher in basal stem cuttings that received the exogenous IBA application; while zeatin riboside, gibberellins, and jasmonic acid were lower than non-treated basal stem cuttings. To explore the underlying molecular mechanism, an isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic technique was employed to identify the expression profiles of proteins at a key period of adventitious root induction (three days after IBA treatment). In total, 3355 differentially expressed proteins (DEPs) were identified. Many DEPs were closely related to carbohydrate metabolism and energy production, protein homeostasis, reactive oxygen and nitric oxide signaling, and cell wall remodeling biological processes; as well as the phytohormone signaling, which was the most critical process in response to IBA treatment. Further, RT-qPCR analysis was used to evaluate the expression level of nine genes that are involved in phytohormone signaling and their transcriptional levels were mostly in accordance with the protein patterns. Finally, a putative work model was proposed. Our study establishes a foundation for further research and sheds light on IBA-mediated AR formation in apple as well as other fruit rootstock cuttings. PMID:29495482

Tetraploidy Enhances Boron-Excess Tolerance in Carrizo Citrange (Citrus sinensis L. Osb. × Poncirus trifoliata L. Raf.)

PubMed Central

Ruiz, Marta; Quiñones, Ana; Martínez-Alcántara, Belén; Aleza, Pablo; Morillon, Raphaël; Navarro, Luis; Primo-Millo, Eduardo; Martínez-Cuenca, Mary-Rus

2016-01-01

Tetraploidy modifies root anatomy which may lead to differentiated capacity to uptake and transport mineral elements. This work provides insights into physiological and molecular characters involved in boron (B) toxicity responses in diploid (2x) and tetraploid (4x) plants of Carrizo citrange (Citrus sinensis L. Osb. × Poncirus trifoliata L. Raf.), a widely used citrus rootstock. With B excess, 2x plants accumulated more B in leaves than 4x plants, which accounted for their higher B uptake and root-to-shoot transport rates. Ploidy did not modify the expression of membrane transporters NIP5 and BOR1 in roots. The cellular allocation of B excess differed between ploidy levels in the soluble fraction, which was lower in 4x leaves, while cell wall-linked B was similar in 2x and 4x genotypes. This correlates with the increased damage and stunted growth recorded in the 2x plants. The 4x roots were found to have fewer root tips, shorter specific root length, longer diameter, thicker exodermis and earlier tissue maturation in root tips, where the Casparian strip was detected at a shorter distance from the root apex than in the 2x roots. The results presented herein suggest that the root anatomical characters of the 4x plants play a key role in their lower B uptake capacity and root-to-shoot transport. Highlights Tetraploidy enhances B excess tolerance in citrange Carrizo Expression of NIP5 and BOR1 transporters and cell wall-bounded B are similar between ploidies B tolerance is attributed to root anatomical modifications induced by genome duplication The rootstock 4x citrange carrizo may prevent citrus trees from B excess. PMID:27252717

Identification of Appropriate Reference Genes for Normalization of miRNA Expression in Grafted Watermelon Plants under Different Nutrient Stresses

PubMed Central

Wu, Weifang; Deng, Qin; Shi, Pibiao; Yang, Jinghua; Hu, Zhongyuan; Zhang, Mingfang

2016-01-01

Watermelon (Citrullus lanatus) is a globally important crop belonging to the family Cucurbitaceae. The grafting technique is commonly used to improve its tolerance to stress, as well as to enhance its nutrient uptake and utilization. It is believed that miRNA is most likely involved in its nutrient-starvation response as a graft-transportable signal. The quantitative real-time reverse transcriptase polymerase chain reaction is the preferred method for miRNA functional analysis, in which reliable reference genes for normalization are crucial to ensure the accuracy. The purpose of this study was to select appropriate reference genes in scion (watermelon) and rootstocks (squash and bottle gourd) of grafted watermelon plants under normal growth conditions and nutrient stresses (nitrogen and phosphorus starvation). Under nutrient starvation, geNorm identified miR167c and miR167f as two most stable genes in both watermelon leaves and squash roots. miR166b was recommended by both geNorm and NormFinder as the best reference in bottle gourd roots under nutrient limitation. Expression of a new Cucurbitaceae miRNA, miR85, was used to validate the reliability of candidate reference genes under nutrient starvation. Moreover, by comparing several target genes expression in qRT-PCR analysis with those in RNA-seq data, miR166b and miR167c were proved to be the most suitable reference genes to normalize miRNA expression under normal growth condition in scion and rootstock tissues, respectively. This study represents the first comprehensive survey of the stability of miRNA reference genes in Cucurbitaceae and provides valuable information for investigating more accurate miRNA expression involving grafted watermelon plants. PMID:27749935

Identification of Appropriate Reference Genes for Normalization of miRNA Expression in Grafted Watermelon Plants under Different Nutrient Stresses.

PubMed

Wu, Weifang; Deng, Qin; Shi, Pibiao; Yang, Jinghua; Hu, Zhongyuan; Zhang, Mingfang

2016-01-01

Watermelon (Citrullus lanatus) is a globally important crop belonging to the family Cucurbitaceae. The grafting technique is commonly used to improve its tolerance to stress, as well as to enhance its nutrient uptake and utilization. It is believed that miRNA is most likely involved in its nutrient-starvation response as a graft-transportable signal. The quantitative real-time reverse transcriptase polymerase chain reaction is the preferred method for miRNA functional analysis, in which reliable reference genes for normalization are crucial to ensure the accuracy. The purpose of this study was to select appropriate reference genes in scion (watermelon) and rootstocks (squash and bottle gourd) of grafted watermelon plants under normal growth conditions and nutrient stresses (nitrogen and phosphorus starvation). Under nutrient starvation, geNorm identified miR167c and miR167f as two most stable genes in both watermelon leaves and squash roots. miR166b was recommended by both geNorm and NormFinder as the best reference in bottle gourd roots under nutrient limitation. Expression of a new Cucurbitaceae miRNA, miR85, was used to validate the reliability of candidate reference genes under nutrient starvation. Moreover, by comparing several target genes expression in qRT-PCR analysis with those in RNA-seq data, miR166b and miR167c were proved to be the most suitable reference genes to normalize miRNA expression under normal growth condition in scion and rootstock tissues, respectively. This study represents the first comprehensive survey of the stability of miRNA reference genes in Cucurbitaceae and provides valuable information for investigating more accurate miRNA expression involving grafted watermelon plants.

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam.

PubMed

Puglisi, Ivana; De Patrizio, Alessandro; Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano; Cacciola, Santa Olga

2017-01-01

Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with 'King' mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam

PubMed Central

Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano

2017-01-01

Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with ‘King’ mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch’s postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on ‘Carrizo’ citrange (C. sinensis ‘Washington Navel’ x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity. PMID:28208159

Identification and Characterization of Citrus tristeza virus Isolates Breaking Resistance in Trifoliate Orange in California.

PubMed

Yokomi, Raymond K; Selvaraj, Vijayanandraj; Maheshwari, Yogita; Saponari, Maria; Giampetruzzi, Annalisa; Chiumenti, Michela; Hajeri, Subhas

2017-07-01

Most Citrus tristeza virus (CTV) isolates in California are biologically mild and symptomless in commercial cultivars on CTV tolerant rootstocks. However, to better define California CTV isolates showing divergent serological and genetic profiles, selected isolates were subjected to deep sequencing of small RNAs. Full-length sequences were assembled, annotated and trifoliate orange resistance-breaking (RB) isolates of CTV were identified. Phylogenetic relationships based on their full genomes placed three isolates in the RB clade: CA-RB-115, CA-RB-AT25, and CA-RB-AT35. The latter two isolates were obtained by aphid transmission from Murcott and Dekopon trees, respectively, containing CTV mixtures. The California RB isolates were further distinguished into two subclades. Group I included CA-RB-115 and CA-RB-AT25 with 99% nucleotide sequence identity with RB type strain NZRB-G90; and group II included CA-RB-AT35 with 99 and 96% sequence identity with Taiwan Pumelo/SP/T1 and HA18-9, respectively. The RB phenotype was confirmed by detecting CTV replication in graft-inoculated Poncirus trifoliata and transmission from P. trifoliata to sweet orange. The California RB isolates induced mild symptoms compared with severe isolates in greenhouse indexing tests. Further examination of 570 CTV accessions, acquired from approximately 1960 and maintained in planta at the Central California Tristeza Eradication Agency, revealed 16 RB positive isolates based on partial p65 sequences. Six isolates collected from 1992 to 2011 from Tulare and Kern counties were CA-RB-115-like; and 10 isolates collected from 1968 to 2010 from Riverside, Fresno, and Kern counties were CA-RB-AT35-like. The presence of the RB genotype is relevant because P. trifoliata and its hybrids are the most popular rootstocks in California.

Potato growth in a porous tube water and nutrient delivery system

NASA Technical Reports Server (NTRS)

Bula, R. J.; Morrow, R. C.; Tibbitts, T. W.

1996-01-01

Potato (Solanum tuberosum L.) cv. 'Norland', vegetative growth and tuber productivity grown in the porous water and nutrient delivery system (PTNDS) developed by the Wisconsin Center for Space Automation and Robotics were compared with the vegetative growth and tuber productivity of plants grown in a peat:vermiculite potting mixture (PT/VR). The plants were grown at 12, 16, and 24-h light periods, 18 degrees C constant temperature, 70% relative humidity, and 300 micromol m-2 s-1 photosynthetic photon flux. Canopy height of plants grown in the PT/VR system was taller than that of plants grown in the PTNDS system. Canopy height differences were greatest when the plants were grown under a 24-h photoperiod. Leaf and stem dry masses were similar for plants grown in the two systems under the 12-h photoperiod. Under the 24-h photoperiod, leaf and stem dry masses of plants grown in the PT/VR system were more than 3 times those of plants grown in the PTNDS system. Tuber dry masses were similar for plants grown in the two systems under the 12-h photoperiod. Under the 24 h-photoperiod, tuber dry weights of plants grown in the PT/VR system were more than twice those of plants grown in the PTNDS system. A slightly higher harvest index (ratio of tuber weight to leaf plus stem weight) was noted for the plants grown in the PTNDS than for the plants grown in the PT/VR system. Plants grown in the PTNDS system at the 24-h photoperiod matured earlier than plants grown at this photoperiod in the PT/VR system. Vegetative growth and tuber productivity of plants grown under the 16-h photoperiod generally were intermediate to those noted for plants grown under the 12 and 24-h photoperiods. These results indicate that potato plants grown in a PTNDS system may require less plant growing volume, mature in a shorter time, and likely produce more tubers per unit area compared with plants grown in the PT/VR system. These plant characteristics are a distinct advantage for a plant growing unit of a CELSS.

Seed-to-seed-to-seed growth and development of Arabidopsis in microgravity.

PubMed

Link, Bruce M; Busse, James S; Stankovic, Bratislav

2014-10-01

Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves.

Study of CdTe quantum dots grown using a two-step annealing method

NASA Astrophysics Data System (ADS)

Sharma, Kriti; Pandey, Praveen K.; Nagpal, Swati; Bhatnagar, P. K.; Mathur, P. C.

2006-02-01

High size dispersion, large average radius of quantum dot and low-volume ratio has been a major hurdle in the development of quantum dot based devices. In the present paper, we have grown CdTe quantum dots in a borosilicate glass matrix using a two-step annealing method. Results of optical characterization and the theoretical model of absorption spectra have shown that quantum dots grown using two-step annealing have lower average radius, lesser size dispersion, higher volume ratio and higher decrease in bulk free energy as compared to quantum dots grown conventionally.

Oxide Ceramic Films Grown on 60 Nitinol for NASA and Department of Defense Applications

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa; Street, Kenneth W.; Lukco, Dorothy; Cytron, Sheldon J.

2005-01-01

Both the NASA Glenn Research Center and the U.S. Army Research Laboratory, Development and Engineering Center (ARDEC) have worked to develop oxide ceramic films grown on 60 nitinol (60-wt% nickel and 40-wt% titanium) to decrease friction and increase wear resistance under unlubricated conditions. In general, oxide and nonoxide ceramic films have unique capabilities as mechanical-, chemical-, and thermal-barrier materials in diverse applications, including high-temperature bearings and gas bearings requiring low friction, wear resistance, and chemical stability. All oxide ceramic films grown on 60 nitinol were furnished by ARDEC, and materials and surface characterization and tribological experiments were conducted at Glenn.

Analysis of peg formation in cucumber seedlings grown on clinostats and in a microgravity (space) environment.

PubMed

Link, B M; Cosgrove, D J

1999-12-01

In young cucumber seedlings, the peg is a polar out-growth of tissue that functions by snagging the seed coat, thereby freeing the cotyledons. Previous studies have indicated that peg formation is gravity dependent. In this study we analyzed peg formation in cucumber seedlings (Cucumis sativus L. cv Burpee Hybrid II) grown under conditions of normal gravity, microgravity, and simulated microgravity (clinostat rotation). Seeds were germinated on the ground, in clinostats and on board the space shuttle (STS 95) for 1-2 days, frozen and subsequently examined for their stage of development, degree of hook formation, number of pegs formed, and peg morphology. The frequency of peg formation in space grown seedlings was found to be nearly identical to that of clinostat grown seedlings and to differ from that of seedlings germinated under normal gravity only in a minority of cases; approximately 6% of the seedlings formed two pegs and nearly 2% of the seedlings lacked pegs, whereas such abnormalities did not occur in ground controls. The degree of hook formation was found to be less pronounced for space grown seedlings, compared to clinostat grown seedlings, indicating a greater degree of decoupling between peg formation and hook formation in space. Nonetheless, in all seedlings having single pegs and a hook, the peg was found to be positioned correctly on the inside of the hook, showing that there is coordinate development even in microgravity environments. Peg morphologies were altered in space grown samples, with the pegs having a blunt appearance and many pegs showing alterations in expansion, with the peg extending out over the edges of the seed coat and downwards. These phenotypes were not observed in clinostat or ground grown seedlings.

Analysis of peg formation in cucumber seedlings grown on clinostats and in a microgravity (space) environment

NASA Technical Reports Server (NTRS)

Link, B. M.; Cosgrove, D. J.

1999-01-01

In young cucumber seedlings, the peg is a polar out-growth of tissue that functions by snagging the seed coat, thereby freeing the cotyledons. Previous studies have indicated that peg formation is gravity dependent. In this study we analyzed peg formation in cucumber seedlings (Cucumis sativus L. cv Burpee Hybrid II) grown under conditions of normal gravity, microgravity, and simulated microgravity (clinostat rotation). Seeds were germinated on the ground, in clinostats and on board the space shuttle (STS 95) for 1-2 days, frozen and subsequently examined for their stage of development, degree of hook formation, number of pegs formed, and peg morphology. The frequency of peg formation in space grown seedlings was found to be nearly identical to that of clinostat grown seedlings and to differ from that of seedlings germinated under normal gravity only in a minority of cases; approximately 6% of the seedlings formed two pegs and nearly 2% of the seedlings lacked pegs, whereas such abnormalities did not occur in ground controls. The degree of hook formation was found to be less pronounced for space grown seedlings, compared to clinostat grown seedlings, indicating a greater degree of decoupling between peg formation and hook formation in space. Nonetheless, in all seedlings having single pegs and a hook, the peg was found to be positioned correctly on the inside of the hook, showing that there is coordinate development even in microgravity environments. Peg morphologies were altered in space grown samples, with the pegs having a blunt appearance and many pegs showing alterations in expansion, with the peg extending out over the edges of the seed coat and downwards. These phenotypes were not observed in clinostat or ground grown seedlings.

Quantification of Pla or 3, a Platanus orientalis Allergen, Grown under Different Environmental Conditions, by Sandwich ELISA.

PubMed

Sedghy, Farnaz; Sankian, Mojtaba; Moghadam, Maliheh; Varasteh, Abdol-Reza

2016-10-01

Platanus species are widely cultured around the world and considered an important cause of allergic reactions. In the present study, we developed a sandwich ELISA to quantify Pla or 3 allergen in P. orientalis pollen extracts grown near high-traffic roads and compared it to pollen extracts collected from rural areas as control. Pollen samples were collected from three polluted and two unpolluted sites in Mashhad, northeast Iran. Recombinant Pla or 3 was expressed and used for polyclonal antibody production in rabbit. A sandwich ELISA was developed and validated to quantify Pla or 3 levels in pollen extracts from the different sites. The coefficients of variation (CVs) for the intra- and inter- day assays were less than 5 and 18%, respectively. The working range of the standard curve was between 0.1 and 25 ng/ml, with the detection limit being 0.037 ng/ml. The recovery percentage was 88-106.4% at working concentrations from 0.31 to 26.5 ng/ml. Pla or 3 levels were significantly greater in pollens grown near high-traffic roads than in those grown in rural regions (p < 0.0001). A sandwich ELISA was developed and validated to quantify Pla or 3 in pollen extracts. Using this validated ELISA, we showed a substantial difference between the amounts of Pla or 3 in pollens grown in different environments. This finding should be considered in developing public policies to reduce traffic pollution, which leads to reduced allergic reactions in atopic subjects.

Symptom development in response to combined infection of in vitro grown Lilium longiflorum with the root lesion nematode Pratylenchus penetrans and soilborne fungi collected from diseased roots of field-grown lilies

USDA-ARS?s Scientific Manuscript database

Eight fungal isolates (ELRF 1-8) were isolated from necrotic roots of Lilium longiflorum cv. Nellie White (Easter lily) grown in a field in the U.S. Pacific Northwest. The eight fungal isolates were identified by sequencing and molecular phylogenetic analyses based on their ITS rDNA region. Five iso...

Developmental and environmental effects on assimilate partitioning in Canada thistle

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

Tworkoski, T.J.

1989-04-01

Canada thistle (Cirsium arvense) plants at three stages of development (rosette, bolt, and flower bud) were grown under spring-simulated or fall-simulated environments. Sucrose export from a single leaf exposed to {sup 14}CO{sub 2} was significantly greater in rosette-plants than bolt- or flower bud-plants during the first two hours after pulse. Twenty-four hours after pulse, total {sup 14}C translocation (dpm) was the same in both environments but the {sup 14}C concentration (dpm/gm) was greater in roots of fall-grown plants. Shoot meristem respiration of fall-grown plants was approximately 50% less than spring-grown plants and was a factor responsible for this trend. Concentrationsmore » of inulin and water-insoluble starch were greater in roots of fall-grown than spring-grown plants and pulsed {sup 14}C accumulated in these fractions. The results suggest that a shift in respiration and metabolism of fall-grown rosette- and bolt-plants leads to increased assimilate movement to the root which may have practical implications for control of this weed.« less

A dark incubation period is important for Agrobacterium-mediated transformation of mature internode explants of sweet orange, grapefruit, citron, and a citrange rootstock.

PubMed

Marutani-Hert, Mizuri; Bowman, Kim D; McCollum, Greg T; Mirkov, T Erik; Evens, Terence J; Niedz, Randall P

2012-01-01

Citrus has an extended juvenile phase and trees can take 2-20 years to transition to the adult reproductive phase and produce fruit. For citrus variety development this substantially prolongs the time before adult traits, such as fruit yield and quality, can be evaluated. Methods to transform tissue from mature citrus trees would shorten the evaluation period via the direct production of adult phase transgenic citrus trees. Factors important for promoting shoot regeneration from internode explants from adult phase citrus trees were identified and included a dark incubation period and the use of the cytokinin zeatin riboside. Transgenic trees were produced from four citrus types including sweet orange, citron, grapefruit, and a trifoliate hybrid using the identified factors and factor settings. The critical importance of a dark incubation period for shoot regeneration was established. These results confirm previous reports on the feasibility of transforming mature tissue from sweet orange and are the first to document the transformation of mature tissue from grapefruit, citron, and a trifoliate hybrid.

A Dark Incubation Period Is Important for Agrobacterium-Mediated Transformation of Mature Internode Explants of Sweet Orange, Grapefruit, Citron, and a Citrange Rootstock

PubMed Central

Marutani-Hert, Mizuri; Bowman, Kim D.; McCollum, Greg T.; Mirkov, T. Erik; Evens, Terence J.; Niedz, Randall P.

2012-01-01

Background Citrus has an extended juvenile phase and trees can take 2–20 years to transition to the adult reproductive phase and produce fruit. For citrus variety development this substantially prolongs the time before adult traits, such as fruit yield and quality, can be evaluated. Methods to transform tissue from mature citrus trees would shorten the evaluation period via the direct production of adult phase transgenic citrus trees. Methodology/Principal Findings Factors important for promoting shoot regeneration from internode explants from adult phase citrus trees were identified and included a dark incubation period and the use of the cytokinin zeatin riboside. Transgenic trees were produced from four citrus types including sweet orange, citron, grapefruit, and a trifoliate hybrid using the identified factors and factor settings. Significance The critical importance of a dark incubation period for shoot regeneration was established. These results confirm previous reports on the feasibility of transforming mature tissue from sweet orange and are the first to document the transformation of mature tissue from grapefruit, citron, and a trifoliate hybrid. PMID:23082165

Cell-wall architecture and lignin composition of wheat developed in a microgravity environment.

PubMed

Levine, L H; Heyenga, A G; Levine, H G; Choi, J; Davin, L B; Krikorian, A D; Lewis, N G

2001-07-01

The microgravity environment encountered during space-flight has long been considered to affect plant growth and developmental processes, including cell wall biopolymer composition and content. As a prelude to studying how microgravity is perceived - and acted upon - by plants, it was first instructive to investigate what gross effects on plant growth and development occurred in microgravity. Thus, wheat seedlings were exposed to microgravity on board the space shuttle Discovery (STS-51) for a 10 day duration, and these specimens were compared with their counterparts grown on Earth under the same conditions (e.g. controls). First, the primary roots of the wheat that developed under both microgravity and 1 g on Earth were examined to assess the role of gravity on cellulose microfibril (CMF) organization and secondary wall thickening patterns. Using a quick freeze/deep etch technique, this revealed that the cell wall CMFs of the space-grown wheat maintained the same organization as their 1 g-grown counterparts. That is, in all instances, CMFs were randomly interwoven with each other in the outermost layers (farthest removed from the plasma membrane), and parallel to each other within the individual strata immediately adjacent to the plasma membranes. The CMF angle in the innermost stratum relative to the immediately adjacent stratum was ca 80 degrees in both the space and Earth-grown plants. Second, all plants grown in microgravity had roots that grew downwards into the agar; they did not display "wandering" and upward growth as previously reported by others. Third, the space-grown wheat also developed normal protoxylem and metaxylem vessel elements with secondary thickening patterns ranging from spiral to regular pit to reticulate thickenings. Fourthly, both the space- and Earth-grown plants were essentially of the same size and height, and their lignin analyses revealed no substantial differences in their amounts and composition regardless of the gravitational field experienced, i.e. for the purposes of this study, all plants were essentially identical. These results suggest that the microgravity environment itself at best only slightly affected either cell wall biopolymer synthesis or the deposition of CMFs, in contrast to previous assertions.

Cell-wall architecture and lignin composition of wheat developed in a microgravity environment

NASA Technical Reports Server (NTRS)

Levine, L. H.; Heyenga, A. G.; Levine, H. G.; Choi, J.; Davin, L. B.; Krikorian, A. D.; Lewis, N. G.; Sager, J. C. (Principal Investigator)

2001-01-01

The microgravity environment encountered during space-flight has long been considered to affect plant growth and developmental processes, including cell wall biopolymer composition and content. As a prelude to studying how microgravity is perceived - and acted upon - by plants, it was first instructive to investigate what gross effects on plant growth and development occurred in microgravity. Thus, wheat seedlings were exposed to microgravity on board the space shuttle Discovery (STS-51) for a 10 day duration, and these specimens were compared with their counterparts grown on Earth under the same conditions (e.g. controls). First, the primary roots of the wheat that developed under both microgravity and 1 g on Earth were examined to assess the role of gravity on cellulose microfibril (CMF) organization and secondary wall thickening patterns. Using a quick freeze/deep etch technique, this revealed that the cell wall CMFs of the space-grown wheat maintained the same organization as their 1 g-grown counterparts. That is, in all instances, CMFs were randomly interwoven with each other in the outermost layers (farthest removed from the plasma membrane), and parallel to each other within the individual strata immediately adjacent to the plasma membranes. The CMF angle in the innermost stratum relative to the immediately adjacent stratum was ca 80 degrees in both the space and Earth-grown plants. Second, all plants grown in microgravity had roots that grew downwards into the agar; they did not display "wandering" and upward growth as previously reported by others. Third, the space-grown wheat also developed normal protoxylem and metaxylem vessel elements with secondary thickening patterns ranging from spiral to regular pit to reticulate thickenings. Fourthly, both the space- and Earth-grown plants were essentially of the same size and height, and their lignin analyses revealed no substantial differences in their amounts and composition regardless of the gravitational field experienced, i.e. for the purposes of this study, all plants were essentially identical. These results suggest that the microgravity environment itself at best only slightly affected either cell wall biopolymer synthesis or the deposition of CMFs, in contrast to previous assertions.

Seed-to-Seed-to-Seed Growth and Development of Arabidopsis in Microgravity

PubMed Central

Link, Bruce M.; Busse, James S.

2014-01-01

Abstract Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves. Key Words: Arabidopsis—Branch—Inflorescence—Microgravity—Morphology—Seed—Space. Astrobiology 14, 866–875. PMID:25317938

Longleaf Pine Root System Development and Seedling Quality in Response to Copper Root Pruning and Cavity Size

Treesearch

Mary Anne Sword Sayer; Shi-Jean Susana Sung; James D. Haywood

2011-01-01

Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling...

Changes in growth, photosynthetic activities, biochemical parameters and amino acid profile of Thompson Seedless grapes (Vitis vinifera L.).

PubMed

Somkuwar, R G; Bahetwar, Anita; Khan, I; Satisha, J; Ramteke, S D; Itroutwar, Prerna; Bhongale, Aarti; Oulkar, Dashrath

2014-11-01

The study on photosynthetic activity and biochemical parameters in Thompson Seedless grapes grafted on Dog Ridge rootstock and its impact on growth, yield and amino acid profile at various stages of berry development was conducted during the year 2012-2013. Leaf and berry samples from ten year old vines of Thompson Seedless were collected at different growth and berry developmental stages. The analysis showed difference in photosynthetic activity, biochemical parameters and amino acid status with the changes in berry development stage. Higher photosynthetic rate of 17.39 umol cm(-2) s(-1) was recorded during 3-4mm berry size and the lowest (10.08 umol cm(-2) s(-1)) was recorded during the veraison stage. The photosynthetic activity showed gradual decrease with the onset of harvest while the different biochemical parameters showed increase and decrease from one stage to another in both berry and leaves. Changes in photosynthetic activity and biochemical parameters thereby affected the growth, yield and amino acid content of the berry. Positive correlation of leaf area and photosynthetic rate was recorded during the period of study. Reducing sugar (352.25 mg g(-1)) and total carbohydrate (132.52 mg g(-1)) was more in berries as compared to leaf. Amino acid profile showed variations in different stages of berry development. Marked variations in photosynthetic as well as biochemical and amino acid content at various berry development stages was recorded and thereby its cumulative effect on the development of fruit quality.

Microbiological Quality and Food Safety of Plants Grown on ISS Project

NASA Technical Reports Server (NTRS)

Wheeler, Raymond M. (Compiler)

2014-01-01

The goal of this project is to select and advance methods to enable real-time sampling, microbiological analysis, and sanitation of crops grown on the International Space Station (ISS). These methods would validate the microbiological quality of crops grown for consumption to ensure safe and palatable fresh foods. This would be achieved through the development / advancement of microbiological sample collection, rapid pathogen detection and effective sanitation methods that are compatible with a microgravity environment.

Gravity, chromosomes, and organized development in aseptically cultured plant cells

NASA Technical Reports Server (NTRS)

Krikorian, Abraham D.

1993-01-01

The objectives of the PCR experiment are: to test the hypothesis that microgravity will in fact affect the pattern and developmental progression of embryogenically competent plant cells from one well-defined, critical stage to another; to determine the effects of microgravity in growth and differentiation of embryogenic carrot cells grown in cell culture; to determine whether microgravity or the space environment fosters an instability of the differentiated state; and to determine whether mitosis and chromosome behavior are adversely affected by microgravity. The methods employed will consist of the following: special embryogenically competent carrot cell cultures will be grown in cell culture chambers provided by NASDA; four cell culture chambers will be used to grow cells in liquid medium; two dishes (plant cell culture dishes) will be used to grow cells on a semi-solid agar support; progression to later embryonic stages will be induced in space via crew intervention and by media manipulation in the case of liquid grown cell cultures; progression to later stages in case of semi-solid cultures will not need crew intervention; embryo stages will be fixed at a specific interval (day 6) in flight only in the case of liquid-grown cultures; and some living cells and somatic embryos will be returned for continued post-flight development and 'grown-out.' These will derive from the semi-solid grown cultures.

Calcium localization in lettuce leaves with and without tipburn: comparison of controlled-environment and field-grown plants

NASA Technical Reports Server (NTRS)

Barta, D. J.; Tibbitts, T. W.

1991-01-01

An electron microprobe was used to determine tissue concentrations of Ca across 20-mm-long leaves of 'Green Lakes' crisphead lettuce (Lactuca sativa L.) with and without tipburn injury. Concentrations within the fifth and 14th leaves, counted from the cotyledons, from plants grown under controlled-environment conditions were compared to concentrations within similar leaves obtained from plants grown under field conditions. Only the 14th leaf from plants grown under controlled-environment conditions developed tipburn. Injured areas on these leaves had Ca concentrations as low as 0.2 to 0.3 mg g-1 dry weight. Uninjured areas of tipburned leaves contained from 0.4 to 0.5 mg g-1 dry weight. Concentrations across the uninjured 14th leaf from field-grown plants averaged 1.0 mg g-1 dry weight. Amounts across the uninjured fifth leaves from both environments averaged 1.6 mg g-1 dry weight. In contrast, Mg concentrations were higher in injured leaves than in uninjured leaves and thus were negatively correlated with Ca concentrations. Magnesium concentrations averaged 4.7 mg g-1 dry weight in injured leaves compared with 3.4 mg g-1 dry weight in uninjured leaves from both environments. Magnesium concentrations were uniform across the leaf. Potassium concentrations were highest at the leaf apex and decreased toward the base and also decreased from the midrib to the margin. Potassium averaged 51 mg g-1 dry weight in injured and uninjured leaves from both environments. No significant differences in K concentration were present between injured and uninjured leaves. This study documented that deficient concentrations of Ca were present in areas of leaf tissue developing tipburn symptoms and that concentrations were significantly higher in similar areas of other leaves that had no symptoms. This study also documented that Ca concentrations were significantly lower in enclosed leaves that exhibited tipburn symptoms than in exposed leaves that did not exhibit tipburn. Also, the amounts of Ca in plants that developed tipburn in controlled environments were lower than in plants of the same cultivar that did not develop tipburn in field plantings. The reduced levels of Ca in plants grown in controlled environments were associated with faster development rates compared with field-grown plants.

Morphology of Arabidopsis Grown under Chronic Centrifugation and on the Clinostat 123

PubMed Central

Brown, Allan H.; Dahl, A. Orville; Chapman, David K.

1976-01-01

Morphological measurements were made on populations of Arabidopsis thaliana grown from seed for 21 days under essentially constant environmental conditions except for the influence of gravitational or centrifugal accelerations. Growth conditions were what had been proposed for experiments in an artificial satellite. Observations are reported for plants grown at normal 1-g upright or on horizontal clinostats and for plants grown on a centrifuge. Increased g-force, up to 15 times normal, was found to have significant but small effects on some morphological end points. The plants' sensitivity to the magnitude of the g-force was much less than to its vector direction. Data from centrifuge experiments (which determined the g-functions for particular characters) were extrapolated to zero-g to predict a set of morphological characteristics of a plant developing in the satellite environment. As an alternative means of predicting properties of a zero-g plant, characteristics of plants grown on horizontal clinostats were measured. The results of these two predictive methods were not in agreement. Clinostat grown plants were morphologically distinct from upright stationary controls. When plants were grown while rotating in the upright position on vertical clinostats they were similar to stationary plants also grown upright, but there were small differences some of which were statistically significant. PMID:16659483

Cavity size and copper root pruning affect production and establishment of container-grown longleaf pine seedlings

Treesearch

Marry Anne Sword Sayer; James D. Haywood; Shi-Jean Susana Sung

2009-01-01

With six container types, we tested the effects of cavity size (i.e., 60, 93, and 170 ml) and copper root pruning on the root system development of longleaf pine (Pinus palustris Mill.) seedlings grown in a greenhouse. We then evaluated root egress during a root growth potential test and assessed seedling morphology and root system development 1 year after planting in...

Early perception of stink bug damage in developing seeds of field-grown soybean induces chemical defences and reduces bug attack.

PubMed

Giacometti, Romina; Barneto, Jesica; Barriga, Lucia G; Sardoy, Pedro M; Balestrasse, Karina; Andrade, Andrea M; Pagano, Eduardo A; Alemano, Sergio G; Zavala, Jorge A

2016-08-01

Southern green stink bugs (Nezara viridula L.) invade field-grown soybean crops, where they feed on developing seeds and inject phytotoxic saliva, which causes yield reduction. Although leaf responses to herbivory are well studied, no information is available about the regulation of defences in seeds. This study demonstrated that mitogen-activated protein kinases MPK3, MPK4 and MPK6 are expressed and activated in developing seeds of field-grown soybean and regulate a defensive response after stink bug damage. Although 10-20 min after stink bug feeding on seeds induced the expression of MPK3, MPK6 and MPK4, only MPK6 was phosphorylated after damage. Herbivory induced an early peak of jasmonic acid (JA) accumulation and ethylene (ET) emission after 3 h in developing seeds, whereas salicylic acid (SA) was also induced early, and at increasing levels up to 72 h after damage. Damaged seeds upregulated defensive genes typically modulated by JA/ET or SA, which in turn reduced the activity of digestive enzymes in the gut of stink bugs. Induced seeds were less preferred by stink bugs. This study shows that stink bug damage induces seed defences, which is perceived early by MPKs that may activate defence metabolic pathways in developing seeds of field-grown soybean. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Very thin, high Ge content Si 0.3Ge 0.7 relaxed buffer grown by MBE on SOI(0 0 1) substrate

NASA Astrophysics Data System (ADS)

Myronov, M.; Shiraki, Y.

2007-04-01

Growth procedure and excellent properties of very thin 240 nm thick, 95% relaxed, high Ge content Si 0.3Ge 0.7 buffer grown on SOI(0 0 1) substrate are demonstrated. All epilayers of the newly developed Si 0.3Ge 0.7/SOI(0 0 1) variable-temperature virtual substrate were grown in a single process by solid-source molecular beam epitaxy. Surface analysis of grown samples revealed smooth, cross-hatch free surface with low root mean square surface roughness of 0.9 nm and low threading dislocations density of 5×10 4 cm -2.

Induced abnormality in Mir- and Earth grown Super Dwarf wheat.

PubMed

Bubenheim, D L; Stieber, J; Campbell, W F; Salisbury, F B; Levinski, M; Sytchev, V; Podolsky, I; Chernova, L; Pdolsky, I

2003-01-01

Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with Earth-grown wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super-Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen gains, however, contained only one nuclei, while normal viable pollen is tri-nucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was the presence of a high level of atmospheric ethylene (1,200 ppb). Ground studies conducted by exposing 'Super-Dwarf' wheat to ethylene just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

Induced abnormality in Mir- and Earth grown Super Dwarf wheat

NASA Technical Reports Server (NTRS)

Bubenheim, D. L.; Stieber, J.; Campbell, W. F.; Salisbury, F. B.; Levinski, M.; Sytchev, V.; Podolsky, I.; Chernova, L.; Pdolsky, I.

2003-01-01

Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with Earth-grown wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super-Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen gains, however, contained only one nuclei, while normal viable pollen is tri-nucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was the presence of a high level of atmospheric ethylene (1,200 ppb). Ground studies conducted by exposing 'Super-Dwarf' wheat to ethylene just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

Chloroplast and reactive oxygen species involvement in apoptotic-like programmed cell death in Arabidopsis suspension cultures

PubMed Central

Doyle, Siamsa M.; Diamond, Mark; McCabe, Paul F.

2010-01-01

Chloroplasts produce reactive oxygen species (ROS) during cellular stress. ROS are known to act as regulators of programmed cell death (PCD) in plant and animal cells, so it is possible that chloroplasts have a role in regulating PCD in green tissue. Arabidopsis thaliana cell suspension cultures are model systems in which to test this, as here it is shown that their cells contain well-developed, functional chloroplasts when grown in the light, but not when grown in the dark. Heat treatment at 55 °C induced apoptotic-like (AL)-PCD in the cultures, but light-grown cultures responded with significantly less AL-PCD than dark-grown cultures. Chloroplast-free light-grown cultures were established using norflurazon, spectinomycin, and lincomycin and these cultures responded to heat treatment with increased AL-PCD, demonstrating that chloroplasts affect AL-PCD induction in light-grown cultures. Antioxidant treatment of light-grown cultures also resulted in increased AL-PCD induction, suggesting that chloroplast-produced ROS may be involved in AL-PCD regulation. Cycloheximide treatment of light-grown cultures prolonged cell viability and attenuated AL-PCD induction; however, this effect was less pronounced in dark-grown cultures, and did not occur in antioxidant-treated light-grown cultures. This suggests that a complex interplay between light, chloroplasts, ROS, and nuclear protein synthesis occurs during plant AL-PCD. The results of this study highlight the importance of taking into account the time-point at which cells are observed and whether the cells are light-grown and chloroplast-containing or not, for any study on plant AL-PCD, as it appears that chloroplasts can play a significant role in AL-PCD regulation. PMID:19933317

Division of Agriculture

Science.gov Websites

Book Fact Sheets 2016 Farmers Markets List Farmers Market Resource Fact Sheets Product Seasonal development of an agriculture industry in the State. Alaska Grown Source Book 2016-2017 Alaska Grown Source Book Alaska Ag Day Proclamation Privacy Copyright System Status State of Alaska Department of Natural

Nucleoli from growing oocytes inhibit the maturation of enucleolated, full-grown oocytes in the pig.

PubMed

Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi; Fulka, Josef

2011-06-01

In mammals, the nucleolus of full-grown oocyte is essential for embryonic development but not for oocyte maturation. In our study, the role of the growing oocyte nucleolus in oocyte maturation was examined by nucleolus removal and/or transfer into previously enucleolated, growing (around 100 µm in diameter) or full-grown (120 µm) pig oocytes. In the first experiment, the nucleoli were aspirated from growing oocytes whose nucleoli had been compacted by actinomycin D treatment, and the enucleolated oocytes were matured in vitro. Most of non-treated or actinomycin D-treated oocytes did not undergo germinal vesicle breakdown (GVBD; 13% and 12%, respectively). However, the GVBD rate of enucleolated, growing oocytes significantly increased to 46%. The low GVBD rate of enucleolated, growing oocytes was restored again by the re-injection of nucleoli from growing oocytes (23%), but not when nucleoli from full-grown oocytes were re-injected into enucleolated, growing oocytes (49%). When enucleolated, full-grown oocytes were injected with nucleoli from growing or full-grown oocytes, the nucleolus in the germinal vesicle was reassembled (73% and 60%, respectively). After maturation, the enucleolated, full-grown oocytes injected with nucleoli from full-grown oocytes matured to metaphase II (56%), whereas injection with growing-oocyte nucleoli reduced this maturation to 21%. These results suggest that the growing-oocyte nucleolus is involved in the oocyte's meiotic arrest, and that the full-grown oocyte nucleolus has lost the ability. Copyright © 2011 Wiley-Liss, Inc.

Relation of quantity of seed sown and density of seedlings to the development and survival of forest planting stock

Treesearch

W. G. Wahlenberg

1929-01-01

It is obvious that seedlings grown in dense stands can not develop so well as those grown without crowding. Nurserymen naturally wish to avoid injury to their stock from crowding, but they also desire to utilize their soil space as fully as possible. The optimum density of stand for each species and age class of nursery stock can be determined within reasonably close...

Field and laboratory root growth and development of Lesquerella germplasm

USDA-ARS?s Scientific Manuscript database

Lesquerella roots have not been fully characterized as compared to other crop species. There is initial information gathered on root trait variation in young seedling grown in laboratory settings but studies to determine if the results can be extrapolated in field grown plants are lacking. We report...

CCROP-Simulation model for container-grown nursery plant production.

USDA-ARS?s Scientific Manuscript database

Container Crop Resource Optimization Program (CCROP) is an integrative model which simulates the growth and water and nutrient requirements of a woody ornamental shrub grown in small (2.8–11.4 L) containers in a field environment with overhead sprinkler irrigation. The model was developed for produc...

High indium content homogenous InAlN layers grown by plasma-assisted molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Kyle, Erin C. H.; Kaun, Stephen W.; Wu, Feng; Bonef, Bastien; Speck, James S.

2016-11-01

InAlN grown by plasma-assisted molecular beam epitaxy often contains a honeycomb microstructure. The honeycomb microstructure consists of 5-10 nm diameter aluminum-rich regions which are surrounded by indium-rich regions. Layers without this microstructure were previously developed for nominally lattice-matched InAlN and have been developed here for higher indium content InAlN. In this study, InAlN was grown in a nitrogen-rich environment with high indium to aluminum flux ratios at low growth temperatures. Samples were characterized by high-resolution x-ray diffraction, atomic force microscopy, high-angle annular dark-field scanning transmission electron microscopy, and atom probe tomography. Atomic force microscopy showed InAlN layers grown at temperatures below 450 °C under nitrogen-rich conditions were free of droplets. InAlN films with indium contents up to 81% were grown at temperatures between 410 and 440 °C. High-angle annular dark-field scanning transmission electron microscopy and atom probe tomography showed no evidence of honeycomb microstructure for samples with indium contents of 34% and 62%. These layers are homogeneous and follow a random alloy distribution. A growth diagram for InAlN of all indium contents is reported.

Resveratrols in grape berry skins and leaves in vitis germplasm.

PubMed

Wang, Lijun; Xu, Man; Liu, Chunyan; Wang, Junfang; Xi, Huifen; Wu, Benhong; Loescher, Wayne; Duan, Wei; Fan, Peige; Li, Shaohua

2013-01-01

Resveratrol is an important stilbene that benefits human health. However, it is only distributed in a few species including grape and is very expensive. At present, grape has been an important source resveratrol. However, the details are scarce on resveratrol distribution in different Vitis species or cultivars. The composition and content of resveratrols were investigated by HPLC for assessing genotypic variation in berry skins and leaves of 75 grape cultivars, belonging to 3 species and 7 interspecific hybrids. Trans-resveratrol, cis-piceid and trans-piceid were detected in berry skins and leaves, but cis-resveratrol was not. Resveratrol content largely varied with genetic background as well as usage. In most cultivars, total resveratrol including the above three compounds was higher in berry skins than leaves. In berry skins of most cultivars and leaves of almost all cultivars, cis-piceid was the most abundant resveratrol; trans-resveratrol and trans-piceid were minor components. Some specific cultivars were found with extremely high levels of trans-resveratrol, cis- piceid, trans-piceid or total resveratrols in berry skins or leaves. In skins and leaves, rootstock cultivars had a higher content of total resveratrols, and the cultivated European type cultivars and their hybrids with V. labrusca had relatively low totals. There were no significant correlations of the amounts of total resveratrols or any individual resveratrol between berry skins and leaves. All 75 cultivars can be divided into four groups based on the composition of resveratrols and their concentration by principal component analysis. Resveratrol content of grape berries and leaves varied largely with their genetic background and usage. Rootstock cultivars had a higher content of total resveratrols than the other germplasm. Total resveratrols were lower in leaves than berry skins in most cultivars. Cis-piceid was the most abundant resveratrol in most cultivars, and trans-res and trans-pd were minor components.

Resveratrols in Grape Berry Skins and Leaves in Vitis Germplasm

PubMed Central

Wang, Lijun; Xu, Man; Liu, Chunyan; Wang, Junfang; Xi, Huifen; Wu, Benhong; Loescher, Wayne; Duan, Wei; Fan, Peige; Li, Shaohua

2013-01-01

Background Resveratrol is an important stilbene that benefits human health. However, it is only distributed in a few species including grape and is very expensive. At present, grape has been an important source resveratrol. However, the details are scarce on resveratrol distribution in different Vitis species or cultivars. Methodology/Principal Finding The composition and content of resveratrols were investigated by HPLC for assessing genotypic variation in berry skins and leaves of 75 grape cultivars, belonging to 3 species and 7 interspecific hybrids. Trans-resveratrol, cis-piceid and trans-piceid were detected in berry skins and leaves, but cis-resveratrol was not. Resveratrol content largely varied with genetic background as well as usage. In most cultivars, total resveratrol including the above three compounds was higher in berry skins than leaves. In berry skins of most cultivars and leaves of almost all cultivars, cis-piceid was the most abundant resveratrol; trans-resveratrol and trans-piceid were minor components. Some specific cultivars were found with extremely high levels of trans-resveratrol, cis- piceid, trans-piceid or total resveratrols in berry skins or leaves. In skins and leaves, rootstock cultivars had a higher content of total resveratrols, and the cultivated European type cultivars and their hybrids with V. labrusca had relatively low totals. There were no significant correlations of the amounts of total resveratrols or any individual resveratrol between berry skins and leaves. All 75 cultivars can be divided into four groups based on the composition of resveratrols and their concentration by principal component analysis. Conclusion Resveratrol content of grape berries and leaves varied largely with their genetic background and usage. Rootstock cultivars had a higher content of total resveratrols than the other germplasm. Total resveratrols were lower in leaves than berry skins in most cultivars. Cis-piceid was the most abundant resveratrol in most cultivars, and trans-res and trans-pd were minor components. PMID:23637874

Low level of pollen-mediated gene flow from cultivated to wild grapevine: consequences for the evolution of the endangered subspecies Vitis vinifera L. subsp. silvestris.

PubMed

Di Vecchi-Staraz, Manuel; Laucou, Valérie; Bruno, Gérard; Lacombe, Thierry; Gerber, Sophie; Bourse, Thibaut; Boselli, Maurizio; This, Patrice

2009-01-01

A parentage and a paternity-based approach were tested for estimation of pollen-mediated gene flow in wild grapevine (Vitis vinifera L. subsp. silvestris), a wind-pollinated species occurring in Mediterranean Europe and southwestern Asia. For this purpose, 305 seedlings collected in 2 years at 2 locations in France from 4 wild female individuals and 417 wild individuals prospected from France and Italy were analyzed using 20 highly polymorphic microsatellite loci. Their profiles were compared with a database consisting of 3203 accessions from the Institut National de la Recherche Agronomique Vassal collection including cultivars, rootstocks, interspecific hybrids, and other wild individuals. Paternity was assigned for 202 (66.2%) of the 305 seedlings, confirming the feasibility of the method. Most of the fertilizing pollen could be assigned to wild males growing nearby. Estimates of pollen immigration from the cultivated compartment (i.e., the totality of cultivars) ranged from 4.2% to 26% from nearby vineyards and from hidden pollinators such as cultivars and rootstocks that had escaped from farms. In an open landscape, the pollen flow was correlated to the distance between individuals, the main pollinator being the closest wild male (accounting for 51.4-86.2% of the pollen flow). In a closed landscape, more complex pollination occurred. Analysis of the parentage of the 417 wild individuals also revealed relationships between nearby wild individuals, but in the case of 12 individuals (3%), analysis revealed pollen immigration from vineyards, confirming the fitness of the hybrid seedlings. These pollen fluxes may have a significant effect on the evolution of wild populations: on the one hand, the low level of pollen-mediated gene flow from cultivated to wild grapevine could contribute to a risk of extinction of the wild compartment (i.e., the totality of the wild individuals). On the other hand, pollen dispersal within the wild populations may induce inbreeding depression of wild grapevines.

Physiological studies of chloramine resistance developed by Klebsiella pneumoniae under low-nutrient growth conditions.

PubMed Central

Stewart, M H; Olson, B H

1992-01-01

This study investigated the physiological mechanisms of resistance to chloramines developed by Klebsiella pneumoniae grown in a nutrient-limited environment. Growth under these conditions resulted in cells that were smaller than cells grown under high-nutrient conditions and extensively aggregated. Cellular aggregates ranged from 10 to more than 10,000 cells per aggregate, with a mean population aggregate size of 90 cells. This aggregation may have been facilitated by the presence of extracellular polymer material. By using glucose as a reference of capsule content, it was determined that growth under low-nutrient conditions produced cells with 8 x 10(-14) to 41 x 10(-14) g of carbohydrate per cell, with a mean +/- standard deviation of 27 x 10(-14) +/- 16 x 10(-14) g of carbohydrate per cell. In comparison, growth under high-nutrient conditions resulted in 2.7 x 10(-14) to 5.9 x 10(-14) g of carbohydrate per cell, with a mean and standard deviation of 4.3 x 10(-14) +/- 1.2 x 10(-14) g of carbohydrate per cell. Cell wall and cell membrane lipids also varied with growth conditions. The ratio of saturated to unsaturated fatty acids in cells grown under low-nutrient conditions was approximately five times greater than that in cells grown under high-nutrient conditions, suggesting possible differences in membrane permeability. An analysis of sulfhydryl (-SH) groups revealed no quantitative difference with respect to growth conditions. However, upon exposure to chloramines, only 33% of the -SH groups of cells grown under low-nutrient conditions were oxidized, compared with 80% oxidization of -SH groups in cells grown under high-nutrient conditions. The reduced effectiveness of chloramine oxidization of -SH groups in cells grown under low-nutrient conditions may be due to restricted penetration of chloramines into the cells, conformational changes of enzymes, or a combination of both factors. The results of this study suggest that chloramine resistance developed under low-nutrient growth conditions may be a function of multiple physiological factors, including cellular aggregation and protection of sulfhydryl groups within the cell. PMID:1444406

Lethal photosensitization of biofilm-grown bacteria

NASA Astrophysics Data System (ADS)

Wilson, Michael

1997-12-01

Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

Photomorphogenesis, photosynthesis, and seed yield of wheat plants grown under red light-emitting diodes (LEDs) with and without supplemental blue lighting

NASA Technical Reports Server (NTRS)

Goins, G. D.; Yorio, N. C.; Sanwo, M. M.; Brown, C. S.; Sager, J. C. (Principal Investigator)

1997-01-01

Red light-emitting diodes (LEDs) are a potential light source for growing plants in spaceflight systems because of their safety, small mass and volume, wavelength specificity, and longevity. Despite these attractive features, red LEDs must satisfy requirements for plant photosynthesis and photomorphogenesis for successful growth and seed yield. To determine the influence of gallium aluminium arsenide (GaAlAs) red LEDs on wheat photomorphogenesis, photosynthesis, and seed yield, wheat (Triticum aestivum L., cv. 'USU-Super Dwarf') plants were grown under red LEDs and compared to plants grown under daylight fluorescent (white) lamps and red LEDs supplemented with either 1% or 10% blue light from blue fluorescent (BF) lamps. Compared to white light-grown plants, wheat grown under red LEDs alone demonstrated less main culm development during vegetative growth through preanthesis, while showing a longer flag leaf at 40 DAP and greater main culm length at final harvest (70 DAP). As supplemental BF light was increased with red LEDs, shoot dry matter and net leaf photosynthesis rate increased. At final harvest, wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to plants grown under white light. Wheat grown under red LEDs+10% BF light had comparable shoot dry matter accumulation and seed yield relative to wheat grown under white light. These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.

An innovative pot system for monitoring the effects of water stress on grapevines and grape quality

NASA Astrophysics Data System (ADS)

Puccioni, Sergio; Leprini, Marco; Mocali, Stefano; Perria, Rita; Priori, Simone; Storchi, Paolo; Zombardo, Alessandra; Costantini, Edoardo

2016-04-01

The advantage of a pot system is the possibility to control many variables and factors with a large number of replicates, obtaining statistically significant results in only one year of experimentation. An innovative pot system for the monitoring of grapevine water stress was set up. The system consists of 99 pots of 70 liters, filled by 3 different soils collected from premium vineyards of the Chianti Classico district (Tuscany). The soils showed different texture (clay-loam, loam and sandy-loam), different gravel and carbonate content, and different available water capacity (AWC). The same soils had been field monitored for grapevine water stress; therefore it was possible to compare the grapevine behaviour both in pot and in field conditions. The grapevine cultivar was Pinot noir clone ENTAV 115, which can be used to investigate the genetic expression in response to environmental factors, since its genome has been sequenced. Different rootstocks theses were compared: not grafted, 1103 Paulsen and M101-14. Each combination rootstock-soil was repeated 9 times. Every pot was equipped for drip irrigation and with electrodes for soil moisture determination by TDR. A non-stop automated control unit recorded meteorological data (temperature and rainfalls), soil temperature and water potential on 9 selected pots. These 9 selected pots were also used to calibrate a model for soil water volume/tension curve. Soil, leaves and grapes samples from each pot were collected for microbial community determination, through NGS analysis. A preliminary study was based on testing the ability of the system to simulate the natural growing conditions of the grapevines. Therefore the grape performances of the potted plants were compared to those of plants cultivated in the vineyards where the soils were taken. In July 2015 three levels of water supply were tested during 5 weeks (up to veraison) in order to study the effects of water stress on the plants and the grape. Later, all the pots were irrigated abundantly until the full ripening of the grapes. The results revealed that a period of water stress during the early stages of bunches growth can induce irreversible changes in the physiology of the plant. Even if the leaf water potential was restored after abundant irrigations, the photosynthetic capacity was compromised, provoking remarkable effects on the composition of the grape. Although the plants produced similar amounts of grape, the water stress reduced the average berry weight. The plants with higher water availability synthesized more sugars and organic acids, while a strong water stress promoted the accumulation of anthocyanins and phenolic compounds. Soil typology and AWC influenced water stress and physiology of plants, and grape yield and quality. As expected, the plants grafted on 1103 Paulsen resulted more productive, while on the 110-14 they showed similar response to water stress that non-grafted vines. The results in the pots confirmed the effect of soil type that was monitored in the field, and highlighted a strong interaction between rootstock, soil, and microbial community. Acknowledgements: Financial support for this project was provided by the Italy - Israel Cooperation in Agricultural Research.

Electron microscopic analysis of gravisensing Chara rhizoids developed under microgravity conditions.

PubMed

Braun, M; Buchen, B; Sievers, A

1999-01-01

Tip-growing, unicellular Chara rhizoids that react gravitropically on Earth developed in microgravity. In microgravity, they grew out from the nodes of the green thallus in random orientation. Development and morphogenesis followed an endogenous program that is not affected by the gravitational field. The cell shape, the polar cytoplasmic organization, and the polar distribution of cell organelles, except for the statoliths, were not different from controls that had grown on earth (ground controls). The ultrastructure of the organelles and the microtubules were well preserved. Microtubules were excluded from the apical zone in both ground controls as well as microgravity-grown rhizoids. The statoliths (vesicles containing BaSO4 crystals in a matrix) in microgravity-grown rhizoids were spread over a larger area (up to 50 microm basal to the tip) than the statoliths of ground controls (10-30 microm). Some statoliths were even located in the subapical zone close to microtubules, which was not observed in ground controls. The crystals in statoliths from microgravity-grown rhizoids appeared more loosely arranged in the vesicle matrix compared with ground controls. The chemical composition of the crystals was identified as BaSO4 by X-ray microanalysis. There is evidence that the amount of BaSO4 in statoliths of rhizoids developed in microgravity is lower than in ground controls, indicating that the gravisensitivity of microgravity-developed rhizoids might be reduced compared with ground controls. Lack of gravity, however, does not affect the process of tip growth and does not inhibit the development of the structures needed for the gravity-sensing machinery.

Managing the College or University Brand: The Board's Perspective

ERIC Educational Resources Information Center

Moore, Robert M.

2010-01-01

A new responsibility--"brand management"--has developed for some boards of trustees as competition for high-achieving students and various types of resources has intensified. As this competition has grown more intense, and as alumni and donor response to publicized rankings has grown more strident, trustees have begun to focus on brand strength…

Quantum cascade lasers grown on silicon.

PubMed

Nguyen-Van, Hoang; Baranov, Alexei N; Loghmari, Zeineb; Cerutti, Laurent; Rodriguez, Jean-Baptiste; Tournet, Julie; Narcy, Gregoire; Boissier, Guilhem; Patriarche, Gilles; Bahriz, Michael; Tournié, Eric; Teissier, Roland

2018-05-08

Technological platforms offering efficient integration of III-V semiconductor lasers with silicon electronics are eagerly awaited by industry. The availability of optoelectronic circuits combining III-V light sources with Si-based photonic and electronic components in a single chip will enable, in particular, the development of ultra-compact spectroscopic systems for mass scale applications. The first circuits of such type were fabricated using heterogeneous integration of semiconductor lasers by bonding the III-V chips onto silicon substrates. Direct epitaxial growth of interband III-V laser diodes on silicon substrates has also been reported, whereas intersubband emitters grown on Si have not yet been demonstrated. We report the first quantum cascade lasers (QCLs) directly grown on a silicon substrate. These InAs/AlSb QCLs grown on Si exhibit high performances, comparable with those of the devices fabricated on their native InAs substrate. The lasers emit near 11 µm, the longest emission wavelength of any laser integrated on Si. Given the wavelength range reachable with InAs/AlSb QCLs, these results open the way to the development of a wide variety of integrated sensors.

Tetraploidy enhances the ability to exclude chloride from leaves in carrizo citrange seedlings.

PubMed

Ruiz, M; Quiñones, A; Martínez-Cuenca, M R; Aleza, P; Morillon, R; Navarro, L; Primo-Millo, E; Martínez-Alcántara, B

2016-10-20

Tetraploid citrus seedlings are more tolerant to salt stress than diploid genotypes. To provide insight into the causes of differences in salt tolerance due to ploidy and thus to better understand Cl - exclusion mechanisms in citrus, diploid and tetraploid seedlings of Carrizo citrange (CC) were grown at 0 (control) and 40mM NaCl (salt-treated) medium for 20 days. Chloride uptake and root-to-shoot translocation rates were on average 1.4-fold higher in diploid than in tetraploid salt-treated plants, which resulted in a greater (1.6-fold) Cl - build up in the leaves of the former. Root hydraulic conductance and leaf transpiration rate were 58% and 17% lower, respectively, in tetraploid than in diploid control plants. Differences remained after salt treatment which reduced these parameters by 30-40% in both genotypes. Morphology of the root system was significantly influenced by ploidy. Tetraploid roots were less branched and with lower number of root tips than those of diploid plants. The cross-section diameter and area were lower in the diploid, and consequently specific root length was higher (1.7-fold) than in tetraploid plants. The exodermis in sections close to the root apex was broader and with higher deposition of suberin in cell walls in the tetraploid than in the diploid genotype. Net CO 2 assimilation rate in tetraploid salt-treated seedlings was 1.5-fold higher than in diploid salt-treated plants, likely due to the loss of photosynthetic capacity of diploid plants induced by Cl - toxicity. Leaf damage was much higher, in terms of burnt area and defoliation, in diploid than in tetraploid salt-treated plants (8- and 6-fold, respectively). Salt treatment significantly reduced (37%) the dry weight of the diploid plants, but did not affect the tetraploids. In conclusion, tetraploid CC plants appear more tolerant to salinization and this effect seems mainly due to differences in morphological and histological traits of roots affecting hydraulic conductance and transpiration rate. These results may suggest that tetraploid CC used as rootstock could improve salt tolerance in citrus trees. Copyright © 2016 Elsevier GmbH. All rights reserved.

The Iron-regulated Transporter, MbNRAMP1, Isolated from Malus baccata is Involved in Fe, Mn and Cd Trafficking

PubMed Central

Xiao, Haihua; Yin, Liping; Xu, Xuefeng; Li, Tianzhong; Han, Zhenhai

2008-01-01

Background and Aims Iron deficiency is one of the most common nutritional disorders in plants, especially in fruit trees grown in calcareous soil. Malus baccata is widely used as an apple rootstock in north China and is highly resistant to low temperatures. There are few studies on iron absorption by this species at the molecular level. It is very important to understand the mechanism of iron uptake and transport in such woody plants. As a helpful tool, the aim of the present study was the cloning and functional analysis of NRAMP (natural resistance-associated macrophage protein) genes from the apple tree in relation to trafficking of micronutrients (Fe, Mn and Cd). Methods Reverse transcription-PCR (RT-PCR) combined with RACE (rapid amplification of cDNA ends) was adopted to isolate the full-length NRAMP1 cDNA. Southern blotting was used to test gene copy information, and northern blot was used to detect the gene's expression level. Complementation experiments using the yeast mutant strains DEY1453 and SLY8 were employed to confirm the iron- and manganese-transporting ability of NRAMP1 from apple, and inductively coupled plasma (ICP) spectrometry was used to measure Cd accumulation in yeast. NRAMP1–green fluorescent protein (GFP) fusion protein was used to determine the cellular localization in yeast. Key Results A 2090 bp cDNA was isolated and named MbNRAMP1. It encodes a predicted polypeptide of 551 amino acids. MbNRAMP1 exists in the M. baccata genome as a single copy and was expressed mainly in roots. MbNRAMP1 rescued the phenotype of yeast mutant strains DEY1453 and SLY8, and also increased Cd2+ sensitivity and accumulation. MbNRAMP1 expression in yeast was largely influenced by iron status, and the expression pattern of MbNRAMP1–GFP varied with the environmental iron nutrition status. Conclusions MbNRAMP1 encodes a functional metal transporter capable of mediating the distribution of ions as well as transport of the micronutrients, Fe and Mn, and the toxic metal, Cd. PMID:18819951

HABIT CHANGES OF Y3Al5O12 AND Y3Ga5O12 GROWN FROM A PbO-PbF2 FLUX,

DTIC Science & Technology

Al2O3 or - Ga2O3 ratio in the melt. Y3Ga5O12 crystals have a pure (211) habit when grown from either a Y2O3- or PbO-rich melt. The crystals develop...small (110) faces when grown from a Ga2O3 - or PbF2-rich melt. Y3Al5O12 crystals have a pure (110) when grown from either a PbF2- or Al2O3-rich melt... Ga2O3 -rich melts. It is believed that the habit variations are caused by changes in either the surface diffusion or step propagation, due to Pb

Reduction of Defects in Germanium-Silicon

NASA Technical Reports Server (NTRS)

2003-01-01

Crystals grown without contact with a container have far superior quality to otherwise similar crystals grown in direct contact with a container. In addition to float-zone processing, detached- Bridgman growth is a promising tool to improve crystal quality, without the limitations of float zoning or the defects introduced by normal Bridgman growth. Goals of this project include the development of the detached Bridgman process to be reproducible and well understood and to quantitatively compare the defect and impurity levels in crystals grown by these three methods. Germanium (Ge) and germanium-silicon (Ge-Si) alloys are being used. At MSFC, we are responsible for the detached Bridgman experiments intended to differentiate among proposed mechanisms of detachment, and to confirm or refine our understanding of detachment. Because the contact angle is critical to determining the conditions for detachment, the sessile drop method was used to measure the contact angles as a function of temperature and composition for a large number of substrates made of potential ampoule materials. Growth experiments have used pyrolytic boron nitride (pBN) and fused silica ampoules with the majority of the detached results occurring predictably in the pBN. Etch pit density (EPD) measurements of normal and detached Bridgman-grown Ge samples show a two order of magnitude improvement in the detached-grown samples. The nature and extent of detachment is determined by using profilometry in conjunction with optical and electron microscopy. The stability of detachment has been analyzed, and an empirical model for the conditions necessary to achieve sufficient stability to maintain detached growth for extended periods has been developed. We have investigated the effects on detachment of ampoule material, pressure difference above and below the melt, and Si concentration; samples that are nearly completely detached can be grown repeatedly in pBN. Current work is concentrated on developing a method to make in situ pressure measurements in the growth ampoules.

Analysis of the Spaceflight Effects on Growth and Development of Super Dwarf Wheat Grown on the Space Station Mir

NASA Technical Reports Server (NTRS)

Levinskikh, M. A.; Sychev, V. N.; Derendyaeva, T. A.; Signalova, O. B.; Salisbury, F. B.; Campbell, W. F.; Bingham, G. E.; Bubenheim, D. L.; Jahns, G.

2000-01-01

The hypothesis being tested is that Super Dwarf wheat, Triticum aestivum L., plants in the Svet Greenhouse onboard the Russian Space Station Mir will complete a life cycle in spaceflight, providing that the environmental conditions necessary for adequate growth on Earth are supplied. Twenty six seeds of wheat were planted in each of 2 rows of 2 root compartments for a total of 104 seeds in Svet. Germination rate at 7 d was 56 and 73% on Mir and 75 and 90% in ground-based controls. Plants were grown throughout the whole cycle of ontogenesis (123 d) with samples gathered at different times to validate the morphological and reproductive stages of the plants. Young plants showed vigorous early seedling growth, with large biomass production, including the formation of 280 floral spikes. Upon return to Earth, comparative analyses showed that the number of tillers and flowers per spikelet were 63.2% and 40% greater, respectively, in Mir-grown plants than in the controls. By contrast, the stem length (52.4%), spike mass (49.2%) and length (23.1%), awn length (75.7%), number of spikelets per spike (42.8%) and number of seeds per spike (100% sterile) from Mir-grown plants were substantially less than the controls. Distribution of moisture and roots throughout the substrate was very good. All florets on Mir-grown spikes ceased development at the same stage of ontogeny. Lack of caryopses formation was attributed to male sterility occurring at different stages of staminal development. Anthers failed to dehisce and pollen grains were smaller and shriveled compared to the controls, suggesting a chronic stress had occurred in the Svet growth chamber. Recent ground-based studies indicated that ethylene, which was measured at 0.3 to 1.8 mg per kilogram in the Mir, almost certainly could have induced male sterility in the wheat plants grown on the Mir.

Comparative Floral Development of Mir-Grown and Ethylene-Treated, Earth-Grown Super Dwarf Wheat

NASA Technical Reports Server (NTRS)

Campbell, William F.; Salisbury, Frank B.; Bugbee, Bruce; Klassen, Steven; Naegle, Erin; Strickland, Darren T.; Bingham, Gail E.; Levinskikh, Margarita; Iljina, Galena M.; Veselova, Tatjana D.

2001-01-01

To study plant growth in microgravity, we grew Super Dwarf wheat (Triticum aestivum L.) in the Svet growth chamber onboard the orbiting Russian space station, Mir, and in identical ground control units at the Institute of BioMedical Problems in Moscow, Russia. Seedling emergence was 56% and 73% in the two root-module compartments on Mir and 75% and 90% on Earth. Growth was vigorous (produced ca. 1 kg dry mass), and individual plants produced 5 to 8 tillers on Mir compared with 3 to 5 on Earth-grown controls. Upon harvest in space and return to Earth, however, all inflorescences of the flight-grown plants were sterile. To ascertain if Super Dwarf wheat responded to the 1.1 to 1.7 micromol/mol atmospheric levels of ethylene measured on the Mir prior to and during flowering, plants on earth were exposed to 0, 1, 3, 10, and 20 micromol/mol of ethylene gas and 1200 micromol/mol CO2 from 7d after emergence to maturity. As in our Mir wheat, plant height, awn length, and the flag leaf were significantly shorter in the ethylene-exposed plants than in controls; inflorescences also exhibited 100% sterility. Scanning electron microscopic (SEM) examination of florets from Mir-grown and ethylene-treated, earth-grown plants showed that development ceased prior to anthesis, and the anthers did not dehisce. Laser scanning confocal microscopic (LSCM) examination of pollen grains from Mir and ethylene-treated plants on earth exhibited zero, one, and occasionally two, but rarely three nuclei; pollen produced in the absence of ethylene was always trinucleate, the normal condition. The scarcity of trinucleate pollen, abrupt cessation of floret development prior to anthesis, and excess tillering in wheat plants on Mir and in ethylene-containing atmospheres on earth build a strong case for the ethylene on Mir as the agent for the induced male sterility and other symptoms, rather than microgravity.

Postharvest evaluation of soilless-grown table grape during storage in modified atmosphere.

PubMed

Cefola, Maria; Pace, Bernardo; Buttaro, Donato; Santamaria, Pietro; Serio, Francesco

2011-09-01

Soilless growth systems, developed mainly for vegetables and ornamental crops, have also been used recently as an alternative to soil culture for table grape in order to achieve optimal production performance. In this study, sensory, physical and chemical parameters were analysed in table grapes obtained from soil and soilless growth systems at harvest and during storage in air or modified atmosphere. At harvest, soilless-grown berries were 30% firmer than those grown in soil. Moreover, they showed 60% higher antioxidant activity and total phenol content than soil-grown fruits. Modified atmosphere storage resulted in a better quality of table grapes compared with those stored in air. Furthermore, soilless growth was more suitable than soil growth for preserving visual quality and controlling rachis browning and weight loss. Since the soilless system produces berries that are cleaner and of higher quality than those grown in soil, the implementation of soilless growth for the production of health-promoting and convenience fruits is suggested. Copyright © 2011 Society of Chemical Industry.

The complete mitochondrial genome sequence of Malus hupehensis var. pinyiensis.

PubMed

Duan, Naibin; Sun, Honghe; Wang, Nan; Fei, Zhangjun; Chen, Xuesen

2016-07-01

The complete mitochondrial genome sequence of Malus hupehensis var. pinyiensis, a widely used apple rootstock, was determined using the Illumina high-throughput sequencing approach. The genome is 422,555 bp in length and has a GC content of 45.21%. It is separated by a pair of inverted repeats of 32,504 bp, to form a large single copy region of 213,055 bp and a small single copy region of 144,492 bp. The genome contains 38 protein-coding genes, four pseudogenes, 25 tRNA genes, and three rRNA genes. The genome is 25,608 bp longer than that of M. domestica, and several structural variations between these two mitogenomes were detected.

Genomewide analysis of TCP transcription factor gene family in Malus domestica.

PubMed

Xu, Ruirui; Sun, Peng; Jia, Fengjuan; Lu, Longtao; Li, Yuanyuan; Zhang, Shizhong; Huang, Jinguang

2014-12-01

Teosinte branched 1/cycloidea/proliferating cell factor 1 (TCP) proteins are a large family of transcriptional regulators in angiosperms. They are involved in various biological processes, including development and plant metabolism pathways. In this study, a total of 52 TCP genes were identified in apple (Malus domestica) genome. Bioinformatic methods were employed to predicate and analyse their relevant gene classification, gene structure, chromosome location, sequence alignment and conserved domains of MdTCP proteins. Expression analysis from microarray data showed that the expression levels of 28 and 51 MdTCP genes changed during the ripening and rootstock-scion interaction processes, respectively. The expression patterns of 12 selected MdTCP genes were analysed in different tissues and in response to abiotic stresses. All of the selected genes were detected in at least one of the tissues tested, and most of them were modulated by adverse treatments indicating that the MdTCPs were involved in various developmental and physiological processes. To the best of our knowledge, this is the first study of a genomewide analysis of apple TCP gene family. These results provide valuable information for studies on functions of the TCP transcription factor genes in apple.

Simultaneous determination of glucose, fructose, sucrose and sorbitol in the leaf and fruit peel of different apple cultivars by the HPLC-RI optimized method.

PubMed

Filip, Miuţa; Vlassa, Mihaela; Coman, Virginia; Halmagyi, Adela

2016-05-15

A high performance liquid chromatography method with refractive index detection (HPLC-RI), for simultaneous determination of glucose, fructose, sucrose and sorbitol in leaf and/or apple peel samples from nine apple (Malus domestica Borkh.) cultivars and rootstocks, originating from a germplasm collection, has been developed and validated. Box-Behnken design of response surface methodology was applied for the method optimization. The Carbosep Coregel 87H3 column was used under the optimum conditions predicted: mobile phase of H2SO4 0.005 mol L(-1) solution, flow rate of 0.3 mL min(-1) and column temperature of 35°C. The method was validated for linearity (R(2)>0.99), limits of detection (2.67-4.83 μg mL(-1)) and quantification (8.9-16.1 μg mL(-1)), precision (%RSD<5.05) and recovery (93.94-103.06%) and satisfactory results obtained. The sugars content varied across micropropagated plants in vitro, plants regenerated after cryostorage, growing trees in vivo, and fruit peel. Copyright © 2015 Elsevier Ltd. All rights reserved.

POULTRY-RELATED MICROBIOME CHANGES FROM EMBRYONIC DEVELOPMENT TO FINAL PRODUCT: A SINGLE PASTURED-RAISED FLOCK FARM-TO-FORK ANALYSIS

USDA-ARS?s Scientific Manuscript database

Background: While conventionally grown poultry continues to dominate the U.S. poultry industry, there is an increasing demand for locally-grown, “all natural” alternatives. Unfortunately, limited research has been done on this type of poultry management practice, and thus many of these management e...

75 FR 46859 - Lacey Act Implementation Plan; Definitions for Exempt and Regulated Articles

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-04

... plants of species grown on a commercial scale. As we propose to define them, these terms would apply to... cultivar. A plant (except a tree) that: (a) Has been developed through selective breeding or other means... concern, while exempting plants grown on a commercial scale. They are also designed to be consistent with...

Estimating leaf area and leaf biomass of open-grown deciduous urban trees

Treesearch

David J. Nowak

1996-01-01

Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas.

Biotech/GM crops in horticulture: plum cv. HoneySweet resistant to plum pox virus

USDA-ARS?s Scientific Manuscript database

Commercialization of Biotech crops started in 1995. By 2011, genetically modified (GM) crops were grown world-wide on 160 million ha. Only 114.507 ha of GM crops were grown in Europe, of that, 114.490 ha were Bt maize and 17 ha were potato for industrial starch production. Currently, developing c...

Developing above-ground woody biomass equations for open-grown, multiple-stemmed tree species: shelterbelt-grown Russian-olive

Treesearch

Xinhau Zhour; James R. Brandle; Michele M. Schoeneberger; Tala Awada

2007-01-01

Multiple-stemmed tree species are often used in agricultural settings, playing a significant role in natural resource conservation and carbon sequestration. Biomass estimation, whether for modeling growth under different climate scenarios, accounting for carbon sequestered, or inclusion in natural resource inventories, requires equations that can accurately describe...

Benomyl Stimulates Ectomycorrhizal Development by Pisolithus Tinctorius on Shortleaf Pine Grown in Containers

Treesearch

William H. Pawuk; James P. Barnett

1981-01-01

Container-grown shortleaf pine (Pinus echinata Mill.) seedlings inoculated with Pisolithus tinctorius and drenched with benomyl formed more mycorrhizal roots than undrenched seedlings. Seedlings were drenched (2.5, 5, and 10 mg ai in 15 ml of water per individual) prior to sowing and at either 2-, 4-, or 8-week intervals....

Microgravity effects on leaf morphology, cell structure, carbon metabolism and mRNA expression of dwarf wheat.

PubMed

Stutte, G W; Monje, O; Hatfield, R D; Paul, A-L; Ferl, R J; Simone, C G

2006-10-01

The use of higher plants as the basis for a biological life support system that regenerates the atmosphere, purifies water, and produces food has been proposed for long duration space missions. The objective of these experiments was to determine what effects microgravity (microg) had on chloroplast development, carbohydrate metabolism and gene expression in developing leaves of Triticum aestivum L. cv. USU Apogee. Gravity naive wheat plants were sampled from a series of seven 21-day experiments conducted during Increment IV of the International Space Station. These samples were fixed in either 3% glutaraldehyde or RNAlater or frozen at -25 degrees C for subsequent analysis. In addition, leaf samples were collected from 24- and 14-day-old plants during the mission that were returned to Earth for analysis. Plants grown under identical light, temperature, relative humidity, photoperiod, CO(2), and planting density were used as ground controls. At the morphological level, there was little difference in the development of cells of wheat under microg conditions. Leaves developed in mug have thinner cross-sectional area than the 1g grown plants. Ultrastructurally, the chloroplasts of microg grown plants were more ovoid than those developed at 1g, and the thylakoid membranes had a trend to greater packing density. No differences were observed in the starch, soluble sugar, or lignin content of the leaves grown in microg or 1g conditions. Furthermore, no differences in gene expression were detected leaf samples collected at microg from 24-day-old leaves, suggesting that the spaceflight environment had minimal impact on wheat metabolism.

Balancing photosynthetic light-harvesting and light-utilization capacities in potato leaf tissue during acclimation to different growth temperatures

NASA Technical Reports Server (NTRS)

Steffen, K. L.; Wheeler, R. M.; Arora, R.; Palta, J. P.; Tibbitts, T. W.

1995-01-01

We investigated the effect of temperature during growth and development on the relationship between light-harvesting capacity, indicated by chlorophyll concentration, and light-utilization potential, indicated by light- and bicarbonate-saturated photosynthetic oxygen evolution, in Solanum tuberosum L. cv. Norland. Clonal plantlets were transplanted and grown at 20 degrees C for 2 weeks before transfer to 12, 16, 20, 24 and 28 degrees C for 6 weeks. After 4 weeks of the temperature treatments, leaf tissue fresh weights per area were one-third higher in plants grown at 12 degrees C vs those grown at 28 degrees C. Conversely, chlorophyll content per area in tissue grown at 12 degrees C was less than one-half of that of tissue grown at 28 degrees C at 4 weeks. Photosynthetic capacity measured at a common temperature of 20 degrees C and expressed on a chlorophyll basis was inversely proportional to growth temperature. Leaf tissue from plants grown at 12 degrees C for 4 weeks had photosynthetic rates that were 3-fold higher on a chlorophyll basis than comparable tissue from plants grown at 28 degrees C. These results suggest that the relationship between light-harvesting capacity and light-utilization potential varies 3-fold in response to the growth temperatures examined. The role of this response in avoidance of photoinhibition is discussed.

Crystal Growth of ZnSe and Related Ternary Compound Semiconductors by Vapor Transport in Low Gravity

NASA Technical Reports Server (NTRS)

Su, Ching-Hua; Ramachandran, N.

2013-01-01

Crystals of ZnSe and related ternary compounds, such as ZnSeS and ZnSeTe, will be grown by physical vapor transport in the Material Science Research Rack (MSRR) on International Space Station (ISS). The objective of the project is to determine the relative contributions of gravity-driven fluid flows to the compositional distribution, incorporation of impurities and defects, and deviation from stoichiometry observed in the crystals grown by vapor transport as results of buoyance-driven convection and growth interface fluctuations caused by irregular fluid-flows on Earth. The investigation consists of extensive ground-based experimental and theoretical research efforts and concurrent flight experimentation. The objectives of the ground-based studies are (1) obtain the experimental data and conduct the analyses required to define the optimum growth parameters for the flight experiments, (2) perfect various characterization techniques to establish the standard procedure for material characterization, (3) quantitatively establish the characteristics of the crystals grown on Earth as a basis for subsequent comparative evaluations of the crystals grown in a low-gravity environment and (4) develop theoretical and analytical methods required for such evaluations. ZnSe and related ternary compounds have been grown by vapor transport technique with real time in-situ non-invasive monitoring techniques. The grown crystals have been characterized extensively by various techniques to correlate the grown crystal properties with the growth conditions.

Biotechnological strategies and tools for Plum pox virus resistance: trans-, intra-, cis-genesis, and beyond

PubMed Central

Ilardi, Vincenza; Tavazza, Mario

2015-01-01

Plum pox virus (PPV) is the etiological agent of sharka, the most devastating and economically important viral disease affecting Prunus species. It is widespread in most stone fruits producing countries even though eradication and quarantine programs are in place. The development of resistant cultivars and rootstocks remains the most ecologically and economically suitable approach to achieve long-term control of sharka disease. However, the few PPV resistance genetic resources found in Prunus germplasm along with some intrinsic biological features of stone fruit trees pose limits for efficient and fast breeding programs. This review focuses on an array of biotechnological strategies and tools, which have been used, or may be exploited to confer PPV resistance. A considerable number of scientific studies clearly indicate that robust and predictable resistance can be achieved by transforming plant species with constructs encoding intron-spliced hairpin RNAs homologous to conserved regions of the PPV genome. In addition, we discuss how recent advances in our understanding of PPV biology can be profitably exploited to develop viral interference strategies. In particular, genetic manipulation of host genes by which PPV accomplishes its infection cycle already permits the creation of intragenic resistant plants. Finally, we review the emerging genome editing technologies based on ZFN, TALEN and CRISPR/Cas9 engineered nucleases and how the knockout of host susceptibility genes will open up next generation of PPV resistant plants. PMID:26106397

Control of seed development in Arabidopsis thaliana by atmospheric oxygen

NASA Technical Reports Server (NTRS)

Kuang, A.; Crispi, M.; Musgrave, M. E.

1998-01-01

Seed development is known to be inhibited completely when plants are grown in oxygen concentrations below 5.1 kPa, but apart from reports of decreased seed weight little is known about embryogenesis at subambient oxygen concentrations above this critical level. Arabidopsis thaliana (L.) Heynh. plants were grown full term under continuous light in premixed atmospheres with oxygen partial pressures of 2.5, 5.1, 10.1, 16.2 and 21.3 kPa O2, 0.035 kPa CO2 and the balance nitrogen. Seeds were harvested for germination tests and microscopy when siliques had yellowed. Seed germination was depressed in O2 treatments below 16.2 kPa, and seeds from plants grown in 2.5 kPa O2 did not germinate at all. Fewer than 25% of the seeds from plants grown in 5.1 kPa oxygen germinated and most of the seedlings appeared abnormal. Light and scanning electron microscopic observation of non-germinated seeds showed that these embryos had stopped growing at different developmental stages depending upon the prevailing oxygen level. Embryos stopped growing at the heart-shaped to linear cotyledon stage in 5.1 kPa O2, at around the curled cotyledon stage in 10.1 kPa O2, and at the premature stage in 16.2 kPa O2. Globular and heart-shaped embryos were observed in sectioned seeds from plants grown in 2.5 kPa O2. Tissue degeneration caused by cell autolysis and changes in cell structure were observed in cotyledons and radicles. Transmission electron microscopy of mature seeds showed that storage substances, such as protein bodies, were reduced in subambient oxygen treatments. The results demonstrate control of embryo development by oxygen in Arabidopsis.

Wheat Response to Differences In Water and Nutritional Status Between Zeoponic and Hydroponic Growth Systems

NASA Technical Reports Server (NTRS)

Steinberg, Susan L.; Ming, Douglas W.; Henderson, Keith E.; Carrier, Chris; Gruener, John E.; Barta, Dan J.; Henninger, Don L.

1999-01-01

Hydroponic culture has traditionally been used for controlled environment life support systems (CELSS) because the optimal environment for roots supports high growth rates. Recent developments in zeoponic substrate and microporous tube irrigation (ZPT) also offer high control of the root environment. This study compared the effect of differences in water and nutrient status of ZPT or hydroponic culture on growth and yield of wheat (Triticum aestivum L., CV 'USU-Apogee'). In a side-by-side test in a controlled environment, wheat was grown in ZPT and recirculating hydroponics to maturity. Water use by plants grown in both culture systems peaked at 15-20 L per square meters per d up to day 40, after which it declined more rapidly for plants grown in ZPT culture due to earlier senescence of leaves. No consistent differences were noted in water status between plants grown in the two culture systems. Although yield was similar, harvest index was 28% lower for plants grown in ZPT versus hydroponic culture. Sterile green tillers made up 12% and 0% of the biomass of plants grown in ZPT and hydroponic culture, respectively. Differences in biomass partitioning were attributed primarily to NH4 -N nutrition of plants grown in ZPT as compared with NO3-N in hydroponic nutrient solution. It was likely that NH4-N induced Ca deficiency produced excess tillering and lower harvest index for plants grown in ZPT culture. These results suggest that further refinements in zeoponic substrate would make ZPT culture a viable alternative for achieving high productivity in a CELSS.

Wheat response to differences in water and nutritional status between zeoponic and hydroponic growth systems

NASA Technical Reports Server (NTRS)

Steinberg, S. L.; Ming, D. W.; Henderson, K. E.; Carrier, C.; Gruener, J. E.; Barta, D. J.; Henninger, D. L.

2000-01-01

Hydroponic culture has traditionally been used for controlled environment life support systems (CELSS) because the optimal environment for roots supports high growth rates. Recent developments in zeoponic substrate and microporous tube irrigation (ZPT) also offer high control of the root environment. This study compared the effect of differences in water and nutrient status of ZPT or hydroponic culture on growth and yield of wheat (Triticum aestivum L. cv. USU-Apogee). In a side-by-side test in a controlled environment, wheat was grown in ZPT and recirculating hydroponics to maturity. Water use by plants grown in both culture systems peaked at 15 to 20 L m-2 d-1 up to Day 40, after which it declined more rapidly for plants grown in ZPT culture due to earlier senescence of leaves. No consistent differences in water status were noted between plants grown in the two culture systems. Although yield was similar, harvest index was 28% lower for plants grown in ZPT than in hydroponic culture. Sterile green tillers made up 12 and 0% of the biomass of plants grown in ZPT and hydroponic culture, respectively. Differences in biomass partitioning were attributed primarily to NH4-N nutrition of plants grown in ZPT compared with NO3-N in hydroponic nutrient solution. It is probable that NH4-N-induced Ca deficiency produced excess tillering and lower harvest index for plants grown in ZPT culture. These results suggest that further refinements in zeoponic substrate would make ZPT culture a viable alternative for achieving high productivity in a CELSS.

Interspecific competition of a new invasive mosquito, Culex coronator, and two container mosquitoes, Aedes albopictus and Cx. quinquefasciatus (Diptera: Culicidae), across different detritus environments.

PubMed

Yee, D A; Skiff, J F

2014-01-01

The mosquito Culex coronator (Dyar and Knab) (Diptera: Culicidae) has undergone rapid range expansion in the United States since 2003, with its historical distribution in the southwest expanding eastward to the Atlantic coast. Although Cx. coronator nominally use small natural aquatic habitats for development, the use of containers (e.g., tires) makes it potentially important as container invasive. To determine the potential ecological effects of Cx. coronator on resident container species, we conducted a laboratory experiment to assess its competitive ability with two common tire-inhabiting species, Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) (Diptera: Culicidae). Larvae were reared under a factorial design with each species alone and in combination (Cx. coronator + Ae. albopictus, Cx. coronator + Cx. quinquefasciatus) across three different resource environments (leaf detritus only, animal detritus only, animal + leaf). Mosquito performance (survival, adult male and female mass, and development time) was measured for each species across treatments. Female Cx. coronator developed slowest when grown with Ae. albopictus, or when grown with leaves only regardless of species combinations; similar patterns emerged for males although species effects were restricted to mass. Few differences were evident in performance for male and female Cx. coronator across detritus environments when grown with Cx. quinquefasciatus. Cx. quinquefasciatus did not vary in mass or development time in the presence of Cx. coronator compared with when grown alone. Ae. albopictus female mass was 15% lower in the presence of Cx. coronator. Survival of Cx. coronator was highest in animal and leaf detritus containers, although survival was generally lower when larvae were grown with Ae. albopictus. These findings suggest that the performance of Cx. coronator is similar to that of Cx. quinquefasciatus but it suffers in the presence of Ae. albopictus under some resource environments.

Crown profile equations for stand-grown western hemlock trees in northwestern Oregon.

Treesearch

David D. Marshall; Gregory P. Johnson; David W. Hann

2003-01-01

Crown profile equations were developed for stand-grown western hemlock(Tsuga heterophylla (Raf.) Sarg.) in northwest Oregon. The profile model uses a segmented approach, dividing the crown into an upper and lower portion at the point of the largest crown width (LCW). The model explains about 86% of the variation in crown width when LCW is known but...

Simulating phosphorus removal from a vertical-flow constructed wetland grown with C alternifolius species

Treesearch

Ying Ouyang; Lihua Cui; Gary Feng; John Read

2015-01-01

Vertical flow constructed wetland (VFCW) is a promising technique for removal of excess nutrients and certain pollutants from wastewaters. The aim of this study was to develop a STELLA (structural thinking, experiential learning laboratory with animation) model for estimating phosphorus (P) removal in an artificial VFCW (i.e., a substrate column with six zones) grown...

Staff Governance and Institutional Policy Formation. Educational Policy in the 21st Century: Opportunities, Challenges and Solutions

ERIC Educational Resources Information Center

Murray, John W., Ed.; Miller, Michael T., Ed.

2011-01-01

The number of staff members serving American higher education institutions has more than doubled in the past twenty years, as occupations in technology, development, government relations, and even athletic administration have grown as never before in the history of the academy. As the number, variety, and importance of these positions have grown,…

Nucleolus in clinostat-grown plants

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

Shen-Miller, J.; Dannenhoffer, J.; Hinchman, R.

1991-05-01

The clinostat is an apparatus that is used to mimic zero gravity in studies of plant growth in the absence of gravitropic response. Clinostat-grown tissue cultures of carrot exhibit significant increases both in the number of nuclei containing more than one nucleolus and in nucleolar volume. Oat seedlings germinated and grown on clinostats exhibit a decreased rate of shoot elongation, increased tissue sensitivity to applied auxin, and an increased response to gravitropic stimulation. Clinostat treatment clearly affects plant metabolism. The nucleolus is the region in the nucleus where ribosome synthesis and assembly take place. The 18S, 5.8S, and 25S ribosomalmore » genes, in tandem units, are located in the nucleolus. Ribosomes orchestrate the production of all proteins that are necessary for the maintenance of cell growth, development, and survival. A full study of the effects of nullification of gravitropism, by clinostat rotation, on nucleolar development in barley has been initiated. The authors study developmental changes of nucleolar number and diameter in clinostat-grown root tissues. Preliminary results show that barley roots exhibit changes in nucleolar number and diameter. Growth rates of barley root and shoot also appear to be reduced, in measurements of both length and weight.« less

Status of porous tube plant growth unit research - Development of a plant nutrient delivery system for space

NASA Technical Reports Server (NTRS)

Dreschel, T. W.; Wheeler, R. M.; Sager, J. C.

1988-01-01

A system developed for plant production in space was used to grow wheat, beans, rice, and white potatoes. It was found that the negative gauge pressure used to control the nutrient solution at the root/membrane interface and the pore size influence plant production. The results suggest that wheat, rice, beans, and lettuce can probably be grown with production values resembling those of plants grown in other media. Potato growth seemed to be stunted; this could be a possible response to root restriction.

Neural signal registration and analysis of axons grown in microchannels

NASA Astrophysics Data System (ADS)

Pigareva, Y.; Malishev, E.; Gladkov, A.; Kolpakov, V.; Bukatin, A.; Mukhina, I.; Kazantsev, V.; Pimashkin, A.

2016-08-01

Registration of neuronal bioelectrical signals remains one of the main physical tools to study fundamental mechanisms of signal processing in the brain. Neurons generate spiking patterns which propagate through complex map of neural network connectivity. Extracellular recording of isolated axons grown in microchannels provides amplification of the signal for detailed study of spike propagation. In this study we used neuronal hippocampal cultures grown in microfluidic devices combined with microelectrode arrays to investigate a changes of electrical activity during neural network development. We found that after 5 days in vitro after culture plating the spiking activity appears first in microchannels and on the next 2-3 days appears on the electrodes of overall neural network. We conclude that such approach provides a convenient method to study neural signal processing and functional structure development on a single cell and network level of the neuronal culture.

Induced Abnormality In Mir- and Earth-Grown Super Dwarf Wheat

NASA Technical Reports Server (NTRS)

Bubenheim, David L.; Stieber, Joseph; Campbell, William F.; Salisbury, Frank B.; Levinski, Margarita; Sytchev, Vladimir; Podolsky, Igor; Chernova, Lola; Ivanova, Irene; Kliss, Mark (Technical Monitor)

1998-01-01

Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with normal wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen grains however, contain only one nucleus, while normal viable pollen is trinucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was identified - a high level of atmospheric ethylene (1200 ppb). Ground studies conducted exposing "Super-dwarf" wheat to ethylene at just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples.

Preliminary assessment of systems for deriving liquid and gaseous fuels from waste or grown organics

NASA Technical Reports Server (NTRS)

Graham, R. W.; Reynolds, T. W.; Hsu, Y. Y.

1976-01-01

The overall feasibility of the chemical conversion of waste or grown organic matter to fuel is examined from the technical, economic, and social viewpoints. The energy contribution from a system that uses waste and grown organic feedstocks is estimated as 4 to 12 percent of our current energy consumption. Estimates of today's market prices for these fuels are included. Economic and social issues are as important as technology in determining the feasibility of such a proposal. An orderly program of development and demonstration is recommended to provide reliable data for an assessment of the viability of the proposal.

Effect of lamp type and temperature on development, carbon partitioning and yield of soybean

NASA Astrophysics Data System (ADS)

Dougher, T. A. O.; Bugbee, B.

1997-01-01

Soybeans grown in controlled environments are commonly taller than field-grown plants. In controlled environments, including liquid hydroponics, height of the dwarf cultivar ``Hoyt'' was reduced from 46 to 33 cm when plants were grown under metal halide lamps compared to high pressure sodium lamps at the same photosynthetic photon flux. Metal halide lamps reduced total biomass 14% but did not significantly reduce seed yield. Neither increasing temperature nor altering the difference between day/night temperature affected plant height. Increasing temperature from 21 to 27 degC increased yield 32%. High temperature significantly increased carbon partitioning to stems and increased harvest index.

Membrane proteins involved in transport, vesicle traffic and Ca(2+) signaling increase in beetroots grown in saline soils.

PubMed

Lino, Bárbara; Chagolla, Alicia; E González de la Vara, Luis

2016-07-01

By separating plasma membrane proteins according to their hydropathy from beetroots grown in saline soils, several proteins probably involved in salt tolerance were identified by mass spectrometry. Beetroots, as a salt-tolerant crop, have developed mechanisms to cope with stresses associated with saline soils. To observe which plasma membrane (PM) proteins were more abundant in beet roots grown in saline soils, beet root plants were irrigated with water or 0.2 M NaCl. PM-enriched membrane preparations were obtained from these plants, and their proteins were separated according to their hydropathy by serial phase partitioning with Triton X-114. Some proteins whose abundance increased visibly in membranes from salt-grown beetroots were identified by mass spectrometry. Among them, there was a V-type H(+)-ATPase (probably from contaminating vacuolar membranes), which increased with salt at all stages of beetroots' development. Proteins involved in solute transport (an H(+)-transporting PPase and annexins), vesicle traffic (clathrin and synaptotagmins), signal perception and transduction (protein kinases and phospholipases, mostly involved in calcium signaling) and metabolism, appeared to increase in salt-grown beetroot PM-enriched membranes. These results suggest that PM and vacuolar proteins involved in transport, metabolism and signal transduction increase in beet roots adapted to saline soils. In addition, these results show that serial phase partitioning with Triton X-114 is a useful method to separate membrane proteins for their identification by mass spectrometry.

An endogenous growth pattern of roots is revealed in seedlings grown in microgravity.

PubMed

Millar, Katherine D L; Johnson, Christina M; Edelmann, Richard E; Kiss, John Z

2011-10-01

In plants, sensitive and selective mechanisms have evolved to perceive and respond to light and gravity. We investigated the effects of microgravity on the growth and development of Arabidopsis thaliana (ecotype Landsberg) in a spaceflight experiment. These studies were performed with the Biological Research in Canisters (BRIC) hardware system in the middeck region of the space shuttle during mission STS-131 in April 2010. Seedlings were grown on nutrient agar in Petri dishes in BRIC hardware under dark conditions and then fixed in flight with paraformaldehyde, glutaraldehyde, or RNAlater. Although the long-term objective was to study the role of the actin cytoskeleton in gravity perception, in this article we focus on the analysis of morphology of seedlings that developed in microgravity. While previous spaceflight studies noted deleterious morphological effects due to the accumulation of ethylene gas, no such effects were observed in seedlings grown with the BRIC system. Seed germination was 89% in the spaceflight experiment and 91% in the ground control, and seedlings grew equally well in both conditions. However, roots of space-grown seedlings exhibited a significant difference (compared to the ground controls) in overall growth patterns in that they skewed to one direction. In addition, a greater number of adventitious roots formed from the axis of the hypocotyls in the flight-grown plants. Our hypothesis is that an endogenous response in plants causes the roots to skew and that this default growth response is largely masked by the normal 1 g conditions on Earth.

Multilayer porous structures of HVPE and MOCVD grown GaN for photonic applications

NASA Astrophysics Data System (ADS)

Braniste, T.; Ciers, Joachim; Monaico, Ed.; Martin, D.; Carlin, J.-F.; Ursaki, V. V.; Sergentu, V. V.; Tiginyanu, I. M.; Grandjean, N.

2017-02-01

In this paper we report on a comparative study of electrochemical processes for the preparation of multilayer porous structures in hydride vapor phase epitaxy (HVPE) and metal organic chemical vapor phase deposition (MOCVD) grown GaN. It was found that in HVPE-grown GaN, multilayer porous structures are obtained due to self-organization processes leading to a fine modulation of doping during the crystal growth. However, these processes are not totally under control. Multilayer porous structures with a controlled design have been produced by optimizing the technological process of electrochemical etching in MOCVD-grown samples, consisting of five pairs of thin layers with alternating-doping profiles. The samples have been characterized by SEM imaging, photoluminescence spectroscopy, and micro-reflectivity measurements, accompanied by transfer matrix analysis and simulations by a method developed for the calculation of optical reflection spectra. We demonstrate the applicability of the produced structures for the design of Bragg reflectors.

Growth and Development Temperature Influences Level of Tolerance to High Light Stress 1

PubMed Central

Steffen, Kenneth L.; Palta, Jiwan P.

1989-01-01

The influence of growth and development temperature on the relative tolerance of photosynthetic tissue to high light stress at chilling temperatures was investigated. Two tuber-bearing potato species, Solanum tuberosum L. cv Red Pontiac and Solanum commersonii were grown for 4 weeks, at either 12 or 24°C with 12 hours of about 375 micromoles per second per square meter of photosynthetically active radiation. Paired leaf discs were cut from directly across the midvein of leaflets of comparable developmental stage and light environment from each species at each growth temperature treatment. One disc of each pair was exposed to 1°C and about 1000 micromoles per second per square meter photosynthetically active radiation for 4 hours, and the other disc was held at 1°C in total darkness for the same duration. Photosynthetic tissue of S. tuberosum, developed at 12°C, was much more tolerant to high light and low temperature stress than tissue developed under 24°C conditions. Following the high light treatment, 24°C-grown S. tuberosum tissue demonstrated light-limited and light-saturated rates that were approximately 50% of their paired dark controls. In contrast, the 12°C-grown tissue from S. tuberosum that was subjected to the light stress showed only a 18 and 6% reduction in light-limited and light-saturated rates of photosynthetic oxygen evolution, respectively. Tissue from 24°C-grown S. commersonii was much less sensitive to the light stress than was tissue from S. tuberosum grown under the same conditions. The results presented here demonstrate that: (a) acclimation of S. tuberosum to lower temperature growth conditions with a constant light environment, results in the increased capacity of photosynthetic tissue to tolerate high light stress at chilling temperature and (b) following growth and development at relatively high temperatures S. commersonii, a frost- and heat-tolerant wild species, has a much greater tolerance to the high light stress at chilling temperature than does S. tuberosum cv Red Pontiac, a frost-sensitive cultivated species. PMID:16667216

Effects of CO2 enrichment and drought pretreatment on metabolite responses to water stress and subsequent rehydration using potato tubers from plants grown in sunlit SPAR chambers

USDA-ARS?s Scientific Manuscript database

Experiments were performed using naturally sunlit Soil–Plant–Atmosphere-Research chambers that provided ambient or elevated CO2. Potato plants were grown in pots that were water sufficient (W), water insufficient for 12 to 18 days during both vegetative and tuber development stages (VR), or water i...

Development of 1300 nm GaAs-Based Microcavity Light-Emitting Diodes

DTIC Science & Technology

2001-06-01

vertical - cavity surface emitting lasers ( VCSEL ) and micro- cavity light- emitting diodes (MC-LED) for short-to-medium... epitaxial growth run [1 ]. Self-organized In(Ga)As quantum dot (QD) heterostructures grown by molecular beam epitaxy ( MBE ) are promising candidates as...successfully grown by molecular beam epitaxy on GaAs substrates without the need to rely on any in-situ calibration technique. Fabricated

Effects of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species.

PubMed

Caglar, S; Akgun, A

2006-07-01

The experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species used as rootstocks. The stratified Pistacia seeds were inoculated with VAM fungi. The highest rate of inoculated roots was 96.7% in P. khinjuck seedlings with G. clarum and G. etunicatum, 83.3% in P. vera seedlings with G. caledonium and 73.3% in P. terebinthus seedlings with G. caledonium. Mycorrhizal inoculations improved seedling height only in P. terebinthus. Certain mycorrhizal inoculations increased the leaf N, but not P and K contents. Seedlings inoculated with G. caledonium had higher reducing sugar contents. It was concluded that pre-inoculated Pistacia seedlings could have a better growth in the harsh field conditions.

Analysis of GMO Plum Plant Culture in System Operations Failure

NASA Technical Reports Server (NTRS)

Mercado, Dianne

2017-01-01

GMO plum trees are being evaluated at the Kennedy Space Center as a possible candidate for future space crops. Previously conducted horticultural testing compared the performance of several plum genotypes in controlled environment chambers, resulting in a down-selection to the NASA-11 genotype. Precursory studies determined the water use requirements to sustain the plants as well as the feasibility of grafting non-GMO plum scions onto GMO plum rootstocks of NASA-5, NASA-10, and NASA-11 genotypes. This study follows the growth and horticultural progress of plum trees and in-vitro cultures from August 2017 to November 2017, and provides supplemental support for future GMO plum studies. The presence of Hurricane Irma in early September 2017 resulted in the plants undergoing material deterioration from major changes to their overall horticultural progress.