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Sample records for brachiaria jubata gramineae

  1. Karyotype analysis in Brachiaria (Poaceae) species.

    PubMed

    Bernini, C; Marin-Morales, M A

    2001-01-01

    This is the first karyotype characterization of Brachiaria species. Twelve accessions belonging to five species were analysed. The basic chromosome number was x = 9 and 7, the same reported for the tribe Paniceae. Variations in the chromosome number were observed in B. decumbens (2n = 18; 36) and B. humidicola (2n = 36; 42; 54). Chromosome numbers of 2n = 18 in B. ruziziensis and 2n = 36 in B. brizantha and B. jubata were recorded. Inter- and intraspecific karyotype differentiation of the accessions analysed was facilitated by variations in karyotypic symmetry. The karyotypes were generally considered symmetrical, with a tendency to asymmetry in the direction of the polyploids. It is suggested that addition, deletions and mainly polyploidy have been the most direct causes involved in the chromosome evolution of this genus.

  2. [Nutritional characteristics of Caragana jubata shrub and distribution patterns of soil nutrients in Luya Mountain].

    PubMed

    Zhang, Qiang; Cheng, Bin; Yang, Zhiping; Gao, Chunhua; Zhang, Yigong; Zhang, Lizheng

    2006-12-01

    The study on the nutrient components of Caragana jubata shrub and the distribution patterns of soil nutrients in Luya Mountain of Shanxi Province showed that C. jubata was a valuable feeding plant, which contained 20.27% of crude protein and 5.12% of ash with abundant Ca, Fe and Mn. The crude protein, ash, and mineral element contents increased from May and achieved the highest in July when C. jubata was at flowering stage, and then declined. To adapt to the habitat in subalpine meadow with high altitude, low temperature and thin soil layer, C. jubata had "fertility island" effect. The electric conductivity and the contents of organic matter, total N, available P and available K in the center of "fertility island" increased by 18.8%, 16.4%, 18.7%, 16.6% and 8.4%, respectively, compared with those in the edge of the "fertility island". The organic matter content and total N content in rhizosphere increased, while the contents of available nutrients such as P, K, Fe and Mn decreased, suggesting that C. jubata had high capability of N fixation and nutrients uptake.

  3. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section 201.56-5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... family, Poaceae (Gramineae). Kinds of seed: Bentgrasses, bluegrasses, bluestems, bromes, cereals,...

  4. Lipoxygenase in Caragana jubata responds to low temperature, abscisic acid, methyl jasmonate and salicylic acid.

    PubMed

    Bhardwaj, Pardeep Kumar; Kaur, Jagdeep; Sobti, Ranbir Chander; Ahuja, Paramvir Singh; Kumar, Sanjay

    2011-09-01

    Lipoxygenase (LOX) catalyses oxygenation of free polyunsaturated fatty acids into oxylipins, and is a critical enzyme of the jasmonate signaling pathway. LOX has been shown to be associated with biotic and abiotic stress responses in diverse plant species, though limited data is available with respect to low temperature and the associated cues. Using rapid amplification of cDNA ends, a full-length cDNA (CjLOX) encoding lipoxygenase was cloned from apical buds of Caragana jubata, a temperate plant species that grows under extreme cold. The cDNA obtained was 2952bp long consisting of an open reading frame of 2610bp encoding 869 amino acids protein. Multiple alignment of the deduced amino acid sequence with those of other plants demonstrated putative LH2/ PLAT domain, lipoxygenase iron binding catalytic domain and lipoxygenase_2 signature sequences. CjLOX exhibited up- and down-regulation of gene expression pattern in response to low temperature (LT), abscisic acid (ABA), methyl jasmonate (MJ) and salicylic acid (SA). Among all the treatments, a strong up-regulation was observed in response to MJ. Data suggests an important role of jasmonate signaling pathway in response to LT in C. jubata.

  5. Lineage divergence in Odorrana graminea complex (Anura: Ranidae: Odorrana).

    PubMed

    Xiong, Rongchuan; Li, Cheng; Jiang, Jianping

    2015-05-26

    The confusing and unstable taxonomy of Odorrana livida (Rana livida) since its first record has made it a focal frog complex for systematics. In China, four species, Odorrana nebulosa, O. graminea, O. sinica, O. leporipes, were described to closely resemble O. livida or O. chloronota based on their morphological similarities, accompanied by much taxonomic confusion because of ambiguities in the wide distribution and morphological variations. Currently O. graminea is being used as the name of a provisional monotypic species group to include all the populations in China that closely resemble O. livida or O. chloronota. Here, we conducted a range-wide molecular phylogeographic analysis of the large green odorous frog (Odorrana graminea) complex across the majority of its range in China, based on 2780 bp DNA sequences of three mitochondrial genes (12S, 16S, ND2) in 107 samples from 20 sites. Our data recognized three distinct phylogeographic lineages of the Odorrana graminea (lato sensu) complex in China, and they together with a Thailand lineage formed a monophyletic group. Among the four lineages within O. graminea complex, the average genetic distances based on the concatenated sequences of 12S, 16S and ND2 were 7.5-8.8% and those based on 16S rRNA alone were 4.2-5.5%. Furthermore, canonical discriminant functions in morphometric analyses showed significant separations of all the paired lineage comparisons in China. The aforementioned genetic divergence and mismatched phenotypes among the lineages within the Odorrana graminea complex, in addition to their non-overlapping geographic distributions, imply extensive lineage diversification. However, precise taxonomic status of these lineages needs more studies based on adequate type information and more thorough species delimitation based on analysis of differentiation in bioacoustic and nuclear genetic characters especially regarding gene flow and admixture in geographical contact zones.

  6. Species biology and potential for controlling four exotic plants (Ammophila arenaria, Carpobrotus edulis, Cortaderia jubata and Gasoul crystallinum) on Vandenberg Air Force Base, California

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.; Hinkle, C. Ross

    1987-01-01

    Invasive exotic plants can displace native flora and modify community and ecosystem structure and function. Ammophila arenaria, Corpobrotus edulis, Cortaderia jubata, and Gasoul crystallinum are invasive plants present on Vandenberg Air Force Base, California, designated for study by the Environmental Task Force because of the perceived threat they represent to the native flora. Each plant's native habitat, how they came to be at Vandenberg, their propagation, and how they can be controlled is discussed.

  7. Characterization of gene expression of QM from Caragana jubata, a plant species that grows under extreme cold.

    PubMed

    Bhardwaj, Pardeep Kumar; Ahuja, Paramvir Singh; Kumar, Sanjay

    2010-02-01

    Caragana [Caragana jubata (Pall.) Poir] is a temperate plant that thrives well under extremes of cold in high altitude of Himalaya and hence the plant is expected to be a source of genes that might play an important role in tolerance to low temperature (LT). In order to identify LT inducible gene(s), differential display of mRNA (DD) was performed using the apical buds growing under snow as well as growing in the near vicinity without snow, and a LT inducible QM gene (CjQM) homologue was identified. Realizing the importance of QM gene (which encodes human Wilms' tumor suppressor QM protein) in aggregation of 40 and 60S ribosomal subunit and that not much has been reported on this gene in plant systems in relation to its relationship with LT, full length cDNA of CjQM was cloned through rapid amplification of cDNA ends. The gene (977 bp), encoded by small gene family, had an open reading frame of 651 bp and was found to be intronless. The gene exhibited up-regulation within 20 min of exposure to LT and abscisic acid (ABA), but no significant change in gene expression was observed in response to drought stress (DS), salicylic acid (SA) and methyl jasmonate (MJ) application. Up-regulation of CjQM was obtained in the tissues growing in situ under snow. Non-responsiveness of CjQM towards DS, SA and MJ, but up-regulation in response to LT and ABA suggested a specific regulation of the gene in Caragana under varied cues.

  8. Identification and expression analysis of CjLTI, a novel low temperature responsive gene from Caragana jubata.

    PubMed

    Bhardwaj, Pardeep Kumar; Kaur, Jagdeep; Sobti, Ranbir Chander; Kumar, Sanjay

    2012-03-01

    Using rapid amplification of cDNA ends, a full length cDNA (CjLTI) was cloned from apical buds of Caragana jubata, a plant species that grows under extreme cold. The cDNA obtained was 573 bp long consisting of an open reading frame of 351 bp encoding 116 amino acids. Homology analysis did not exhibit significant similarity with any sequence at NCBI database, therefore it was deduced as a novel gene. Secondary structure analysis suggested that the deduced CjLTI contained 25.86% α-helices, 4.31% β-turns, 6.90% extended strands, and 62.93% random coils. The hydropathy profile suggested CjLTI to be a hydrophobic protein having characteristic features of signal peptides at N-terminus. The gene exhibited down-regulation at 5 min of exposure to low temperature (LT, 4 ± 3 °C) followed by a strong up-regulation after 15 min and onwards. Methyl jasmonate (MJ) lead to up-regulation of CjLTI starting at 5 min onwards. The gene exhibited up- and down-regulation of expression pattern in response to abscisic acid (ABA) and salicylic acid (SA). Mild drought stress slightly up-regulated gene expression and at severe drought (up to 115% reduction in leaf water potential) slight down-regulation of gene expression was observed. These results suggested CjLTI to be a LT responsive gene wherein MJ, ABA and SA pathways might be involved in regulating the gene expression.

  9. Repetitive DNA in three Gramineae species with low DNA content.

    PubMed

    Deshpande, V G; Ranjekar, P K

    1980-08-01

    The genomes of three Gramineae species, namely finger millet (Eleusine coracana), pearl millet (Pennisetum americanum) and rice (Oryza sativa) are characterized by studying their DNA denaturation-reassociation properties. The reassociation kinetics measurement of the sonicated DNA (500--700 nucleotide pairs) indicate the presence of a heterogeneous, repetitive DNA fraction accounting for 49--54% of the total DNA in all three species. From the cot 1/2 value of the slow reassociating DNA, the genome size is estimated as 3.0 X 10(8) np in finger millet, 7.8 X 10(8) np in pearl millet and 9.0 X 10(8) np in rice. The melting patterns of the total DNAs reveal Tm value of 88.6 degrees C in the case of pearl millet and 85.0 degrees C in the case of finger millet and rice. Total repetitive and cot 1.0 DNA fractions in all the three species are isolated and their melting properties are compared with those of respective sonicated DNAs. In finger millet, the Tm values of cot 25 and cot 1 fractions are lower by 10.8 degrees C and 12.8 degrees C, respectively, than that of sonicated DNA and thus exhibit the presence of a base pair mismatch in the range of 10.8--12.8%. In rice, the Tm values of the fractions cot 50 and cot 1 are slightly lower than that of sonicated DNA and reveal a nucleotide mismatching of only 1.8--3.8%. In the case of pearl millet cot 10 DNA fraction a high-melting DNA component (Tm = 92 degrees C) representing 12% of the total cot 10 DNA and a low-melting component with a Tm of 78 degrees C are present. In cot 1 DNA fraction of pearl millet the proportion of the high-melting component is 35% and it has a Tm or 94.8 degrees C. Optical reassociation studies of cot 1.0 DNA fractions have revealed the presence of two kinetically distinct components, namely minor fast-reassociating and major slow-reassociating, having complexities in the range of 330--390 np and 1.28 X 10(5)--6.0 X 10(5) np, respectively in pearl millet and rice and only one DNA fraction with an

  10. Meiotic behavior of Brachiaria decumbens hybrids.

    PubMed

    Souza, V F; Pagliarini, M S; Valle, C B; Bione, N C P; Menon, M U; Mendes-Bonato, A B

    2015-10-21

    Brachiaria decumbens is a forage grass of inestimable value for livestock in Brazil due to its production of good quality forage even when planted on acid and poor soils, although it is susceptible to pasture spittlebugs. Only one cultivar, cv. Basilisk, has been used as the pollen donor in crosses with Brachiaria ruziziensis since 1988 at Embrapa Gado de Corte Research Center. Breeding within the species only became possible from 2009 when sexual accessions were successfully tetraploidized using colchicine. Three sexual genotypes were obtained and hybridization within B. decumbens was finally achieved. Here, we evaluated microspore tetrads using conventional cytology and found meiotic indexes above 78% for all three female genitors (cD24-2, cD24-27, cD24-45), but a low meiotic index (<22%) in the natural apomictic genitor D62 (cv. Basilisk) and in 49 hybrids. Analysis of the relationship between abnormal tetrad frequency and non-viable pollen grains yielded a highly significant Pearson correlation coefficient. The t-test proved significant for the progeny of cD24-45 x D62, with lower abnormalities and pollen sterility when compared to the other two progenies resulting from cD24-2 and cD24-27 crossed to D62, but these two did not differ. Apomictic hybrids such as S036 and X030 with low pollen sterility have the potential for use in cultivar development, whereas the sexual hybrids T012, X072, and X078 might be of use as female genitors in polycross blocks if they display good agronomic traits.

  11. Plant growth promoting bacteria in Brachiaria brizantha.

    PubMed

    Silva, Mylenne Calciolari Pinheiro; Figueiredo, Aline Fernandes; Andreote, Fernando Dini; Cardoso, Elke Jurandy Bran Nogueira

    2013-01-01

    Brachiaria brizantha is considered one of the preferred fodders among farmers for having high forage yield and large production of root mass. The association of beneficial bacteria with these grasses can be very valuable in the recovery of the pasture areas with nutritional deficiency. With the aim of studying this possibility, we carried out the sampling of soil and roots of B. brizantha in three areas (Nova Odessa-SP, São Carlos-SP and Campo Verde-MT, Brazil). Seventy-two bacterial strains were isolated and used in tests to evaluate their biotechnological potential. Almost all isolates presented at least one positive feature. Sixty-eight isolates produced analogues of indole-3-acetic acid, ten showed nitrogenase activity when subjected to the method of increasing the concentration of total nitrogen (total N) in the culture medium and sixty-five isolates showed nitrogenase activity when subjected to acetylene reduction technique. The partial sequencing of 16S rRNA of these isolates allowed the identification of seven main groups, with the prevalence of those affiliated to the genus Stenotrophomonas (69 %). At the end, this work elected the strains C4 (Pseudomonadaceae) and C7 (Rhodospirillaceae) as promising organisms for the development of inoculants due to their higher nitrogenase activity.

  12. Somatic Embryogenesis and Plant Regeneration of Brachiaria brizantha.

    PubMed

    Cabral, Glaucia B; Carneiro, Vera T C; Dusi, Diva M A; Martinelli, Adriana P

    2016-01-01

    The genus Brachiaria (Trin.) Griseb. belongs to the family Poaceae, order Poales, class Monocotyledonae. In Brachiaria brizantha (Hochst. ex A. Rich.) Stapf., embryogenic callus can be induced from seeds from apomictic plants, which results in high frequency somatic embryo development and plant regeneration. We report here a detailed protocol for callus induction from apomictic seed; followed by in vitro morphogenesis (somatic embryo and bud differentiation), plant regeneration, and acclimatization in the greenhouse. Important details regarding the positioning of seeds for callus induction and precautions to avoid endophytic contamination and the occurrence of albino plants are presented.

  13. East with the Night: Longitudinal Migration of the Orinoco Goose (Neochen jubata) between Manú National Park, Peru and the Llanos de Moxos, Bolivia

    PubMed Central

    Davenport, Lisa C.; Nole Bazán, Inés; Carlos Erazo, Nancy

    2012-01-01

    We report on the intra-Amazonian migration of a pair of Orinoco Geese (Neochen jubata) from Manú National Park, Peru. The species is Critically Endangered in Peru, so a major aim of the study was to aid conservation planning by learning the wet season location of the country's last known breeding population. We captured a breeding pair on October 27, 2010, and fitted the birds with Microwave Telemetry, Inc. GPS/Argos satellite PTT's. The pair migrated ∼655 km from Manú National Park to the Llanos de Moxos, Bolivia (Dept. of Bení) in a predominantly longitudinal migration, reaching their final destination on December 23, 2010. Major movements (>5 km per time period) were almost exclusively at night and were undertaken with and without moonlight. Foraging areas used at stopovers in the Llanos de Moxos were remarkably limited, suggesting the importance of grazing lawns maintained by the geese and other herbivores, possibly including cattle. Orinoco Geese are resident in the Llanos de Moxos year-round, so the Manú geese represent a partial migration from the Bení region. We hypothesize that cavity nest limitation explains the partial migration of Orinoco Geese from the Llanos de Moxos. PMID:23056512

  14. 2-Cys peroxiredoxin responds to low temperature and other cues in Caragana jubata, a plant species of cold desert of Himalaya.

    PubMed

    Bhardwaj, Pardeep Kumar; Mala, Deep; Kumar, Sanjay

    2014-05-01

    A 2-Cys peroxiredoxin cDNA (CjPrx) was isolated and characterized from Caragana jubata, a temperate/alpine plant species of high altitude cold desert of Himalaya and Eurasia. The cDNA obtained was 1,064 bp long consisting of an open reading frame of 789 bp encoding 262 amino acids. The calculated molecular mass of the mature protein was 28.88 kDa and pI was 5.84. Deduced amino acid sequence of CjPrx shared a high degree homology with 2-CysPrx proteins from other plants. CjPrx had both the PRX_type 2-Cys domain and thioredoxin-like superfamily domains. CjPrx contained 26.72% α-helices, 6.87% β-turns, 20.61% extended strands and 45.80% random coils, and was a hydrophilic protein. Expression of CjPrx was modulated by low temperature, methyl jasmonate (MJ), salicylic acid and drought stress, but no significant change was observed in response to abscisic acid treatment. Among all the treatments, a strong up-regulation of CjPrx was observed in response to MJ treatment.

  15. Variations of Leaf Cuticular Waxes Among C3 and C4 Gramineae Herbs.

    PubMed

    He, Yuji; Gao, Jianhua; Guo, Na; Guo, Yanjun

    2016-11-01

    Modern C4 plants are commonly distributed in hot and dry environments whereas C3 plants predominate in cool and shade areas. At the outmost of plant surface, the deposition and chemical composition of cuticular waxes vary under different environmental conditions. However, whether such variation of cuticular wax is related to the distribution of C3 and C4 under different environmental conditions is still not clear. In this study, leaves of six C3 Gramineae herbs distributed in spring, Roegneria kamoji, Polypogon fugax, Poa annua, Avena fatua, Alopecurus aequalis, and Oplismenus undulatifolius, and four C4 and one C3 Gramineae herbs distributed in summer, Digitaria sanguinalis, Eleusine indica, Setaria viridis, S. plicata, and O. undulatifolius, were sampled and analyzed for cuticular wax. Plates were the main epicuticular wax morphology in both C3 and C4 plants except S. plicata. The plates melted in C4 plants but not in C3 plants. The total cuticular wax amounts in C4 plants were significantly lower than those in C3 plants, except for O. undulatifolius. Primary alcohols were the most abundant compounds in C3 plants, whereas n-alkanes were relatively the most abundant compounds in C4 plants. C29 was the most abundant n-alkane in C3 plants except for O. undulatifolius, whereas the most abundant n-alkane was C31 or C33 in C4 plants. The average chain length (ACL) of n-alkanes was higher in C4 than in C3 plants, whereas the ACL of n-alkanoic acids was higher in C3 than C4 plants. The cluster analysis based on the distribution of n-alkanes clearly distinguished C3 and C4 plants into two groups, except for O. undulatifolius which was grouped with C4 plants. These results suggest that the variations of cuticular waxes among C3 and C4 Gramineae herbs are related to the distribution of C3 and C4 plants under different environmental conditions.

  16. The effect of ensiling and haymaking on the concentrations of steroidal saponin in two Brachiaria grass species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachiaria (signalgrass) is now the most widely used tropical grass genus in Central and South America. However, Brachiaria spp. can cause hepatogenous photosensitization in livestock. Steroidal saponins, specifically protodioscin, present in Brachiaria spp. may be responsible for liver injury and s...

  17. Evaluation of solar exposure on the experimental intoxication by Brachiaria decumbens in sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-six five-month-old lambs originated from flocks with no previous contact with Brachiaria spp. pastures were divided into three groups. Two groups (GS and GSB) were fed daily with fresh harvested Brachiaria decumbens ad libitum. GS was kept in an area with solar exposure and GSB was kept in st...

  18. Evidence for biological nitrification inhibition in Brachiaria pastures.

    PubMed

    Subbarao, G V; Nakahara, K; Hurtado, M P; Ono, H; Moreta, D E; Salcedo, A F; Yoshihashi, A T; Ishikawa, T; Ishitani, M; Ohnishi-Kameyama, M; Yoshida, M; Rondon, M; Rao, I M; Lascano, C E; Berry, W L; Ito, O

    2009-10-13

    Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named "brachialactone," this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a gamma-lactone ring. It contributed 60-90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in Nitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH(4)(+)) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH(4)(+). Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment.

  19. Abnormal cytokinesis in microsporogenesis of Brachiaria humidicola (Poaceae: Paniceae).

    PubMed

    Adamowski, E V; Boldrini, K R; Pagliarini, M S; do Valle, C B

    2007-09-30

    Microsporogenesis was evaluated in the Brachiaria humidicola collection of the Embrapa Beef Cattle Center, represented by 60 accessions. One accession (H121) presented an abnormal pattern of cytokinesis that had never been reported in this genus. Among 900 meiocytes analyzed in the first division, 10.7% underwent precocious and multiple cytokinesis in metaphase I, fractionating the genome and the cytoplasm into two or more parts. The expected cytokinesis after telophase I did not occur. The abnormal meiocytes from the first division entered the second division but the second cytokinesis after telophase II was also abnormal. Among the 857 meiocytes analyzed in the second division, 10.9% presented abnormal, incomplete or total absence of cytokinesis. Dyads and binucleated microspores were recorded among the meiotic products. The use of this accession in the Embrapa breeding program is compromised.

  20. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions.

    PubMed

    Jiménez, Juan de la Cruz; Cardoso, Juan A; Leiva, Luisa F; Gil, Juanita; Forero, Manuel G; Worthington, Margaret L; Miles, John W; Rao, Idupulapati M

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress.

  1. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions

    PubMed Central

    Jiménez, Juan de la Cruz; Cardoso, Juan A.; Leiva, Luisa F.; Gil, Juanita; Forero, Manuel G.; Worthington, Margaret L.; Miles, John W.; Rao, Idupulapati M.

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress. PMID:28243249

  2. Evidence for biological nitrification inhibition in Brachiaria pastures

    PubMed Central

    Subbarao, G. V.; Nakahara, K.; Hurtado, M. P.; Ono, H.; Moreta, D. E.; Salcedo, A. F.; Yoshihashi, A. T.; Ishikawa, T.; Ishitani, M.; Ohnishi-Kameyama, M.; Yoshida, M.; Rondon, M.; Rao, I. M.; Lascano, C. E.; Berry, W. L.; Ito, O.

    2009-01-01

    Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named “brachialactone,” this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a γ-lactone ring. It contributed 60–90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in Nitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH4+) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH4+. Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment. PMID:19805171

  3. Weather and plant age affect the levels of steroidal saponin and Pithomyces chartarum spores in Brachiaria grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachiaria species are cultivated worldwide in tropical and subtropical climates as the main forage source for ruminants. Numerous tropical and warm-season grasses cause hepatogenous photosensitization, among them several species of Brachiaria. Steroidal saponins present in these plants may be respo...

  4. Mitotic behavior in root tips of Brachiaria genotypes with meiotic chromosome elimination during microsporogenesis.

    PubMed

    Felismino, M F; Silva, N; Pagliarini, M S; Valle, C B

    2008-04-15

    Three accessions of Brachiaria brizantha, three of B. humidicola, and two interspecific hybrids between B. ruziziensis and B. brizantha were analyzed with regard to their mitotic behavior in root tips. All these genotypes revealed chromosome elimination or lack of chromosome affinity in previous analyses of microsporogenesis. Analyses of root tips showed a normal mitotic division in all accessions and hybrids, reinforcing the notion that the genetic control of meiosis is totally independent of that of mitosis. The implications of these findings for the Brachiaria breeding program are discussed.

  5. Effects of tidal action on pollination and reproductive allocation in an estuarine emergent wetland plant-Sagittaria graminea (Alismataceae).

    PubMed

    Zhang, Yanwen; Zhang, Lihui; Zhao, Xingnan; Huang, Shengjun; Zhao, Jimin

    2013-01-01

    In estuarine wetlands, the daily periodic tidal activity has a profound effect on plant growth and reproduction. We studied the effects of tidal action on pollination and reproductive allocation of Sagittaria graminea. Results showed that the species had very different reproductive allocation in tidal and non-tidal habitats. In the tidal area, seed production was only 9.7% of that in non-tidal habitat, however, plants produced more male flowers and nearly twice the corms compared to those in non-tidal habitat. An experiment showed that the time available for effective pollination determined the pollination rate and pollen deposition in the tidal area. A control experiment suggested that low pollen deposition from low visitation frequency is not the main cause of very low seed sets or seed production in this plant in tidal habitat. The negative effects of tides (water) on pollen germination may surpass the influence of low pollen deposition from low visitation frequency. The length of time from pollen deposition to flower being submerged by water affected pollen germination rate on stigmas; more than three hours is necessary to allow pollen germination and complete fertilization to eliminate the risk of pollen grains being washed away by tidal water.

  6. Meiotic behavior of a nonaploid accession endorses x = 6 for Brachiaria humidicola (Poaceae).

    PubMed

    Boldrini, K R; Pagliarini, M S; Valle, C B

    2009-12-01

    Brachiaria humidicola (Poaceae), originally from Africa, is an economically important pasture plant in tropical South America. An accession of B. humidicola (H038) collected from the wild African savanna (Mbeya, Tanzania) showed irregular microsporogenesis. This meiotic behavior was consistent with an allopolyploid origin. Multivalent chromosome association at diakinesis gave tri- to octavalents, associated with two nucleoli in some cells. Six non-congregated univalents in metaphase I and anaphase I, along with previous lines of evidence for x = 6 in B. humidicola, confirm H038 as a nonaploid accession, 2n = 9x = 54. Asynchrony in the genome during microsporogenesis also corroborated this assumption. Its putative origin could be a cross between two related species with different rhythms in meiosis. The meiotic behavior of this accession reinforces the hypothesis of the existence of a new basic chromosome number (x = 6) for Brachiaria. The use of this accession in the breeding of this important forage grass for the tropics is discussed.

  7. Study of the nutrient distribution in root tips of the tropical forage Brachiaria

    NASA Astrophysics Data System (ADS)

    Pineda, C. A.; Wenzl, P.; Mayer, J.; Mesjasz-Przybylowicz, J.; Przybylowicz, W. J.; Prozesky, V. M.

    1997-07-01

    A Brachiaria breeding project is being conducted at CIAT, Colombia to combine acid soil adaptation of B. decumbens with other favourable traits of Brachiaria species that are less adapted to acid soils. Micro-PIXE was applied to investigate nutrient uptake and distribution in root tips of different species grown in hydroponic culture under control and simulated acid soil stress conditions. Different sample measurement approaches were evaluated, including: (1) linear scans with single point measurements along the root axis; (2) mapping of whole root tips; and (3) mapping of root cross sections. Different tissue types could be distinguished on the base of differences in nutrient concentrations and/or Al stress. Al, if supplied under nutrient stress conditions, increased P accumulation in the central vascular tissue of the meristematic and elongation zone of B. decumbens and B. brizantha. Furthermore, a negative correlation was found between Al and Cl accumulation in the root cap of B. decumbens.

  8. Correspondence analysis evaluation of linear nutrient distribution in root tips of the tropical forage Brachiaria brizantha

    NASA Astrophysics Data System (ADS)

    Pineda-Vargas, C. A.; Prozesky, V. M.; Przybylowicz, W. J.; Mayer, J. E.

    2001-07-01

    The technique of correspondence analysis was applied to a set of data obtained from X-ray elemental analysis by nuclear microscopy. Hydroponic experiments simulating tropical acid soil conditions were carried out to determine possible mechanisms of Al-toxicity stress on specific varieties of the genus Brachiaria. In particular the species Brachiaria brizantha was tested for gradient variation along the central cylinder of selected root tips. Single-point irradiations by nuclear microscopy gave some indication of a possible trace element profile gradient along the root axis. To be able to extrapolate the possible correlation and trace elemental concentrations gradients to a more confident level, this nuclear microscopy data obtained was analysed by correspondence analysis. A clear gradient on the plot of the first two axes of the correspondence analysis was found. The correlation of Ca and Cu as well as that of K and Cl were established.

  9. Lectin histochemistry of foam cells in tissues of cattle grazing Brachiaria spp.

    PubMed

    Gomar, M S; Driemeier, D; Colodel, E M; Gimeno, E J

    2005-02-01

    Brachiaria decumbens and B. brizantha (signal grass), which occupy millions of acres in Brazil, are an important source of fodder for ruminants. Sporadic outbreaks of photosensitization in ruminants grazing on signal grass have been reported. Intoxicated animals showed the presence of foamy cells in the liver, spleen, intestinal submucosa and lymph nodes. These foamy cells are macrophages. They are very difficult to distinguish with haematoxylin and eosin stain, especially in the case of isolated cells. The purpose of the present study was to detect specific carbohydrate residues of storage material in the foamy cells in tissues of cattle exposed to Brachiaria spp. The characterization of glycoconjugates provides clues to the pathogenesis of these cells. Besides, the lectin peanut agglutinin was found to be an excellent marker to differentiate and quantify the foam cells, and could be used as a specific marker.

  10. Genome elimination during microsporogenesis in two pentaploid accessions of Brachiaria decumbens (Poaceae).

    PubMed

    Ricci, G C L; Pagliarini, M S; Valle, C B

    2010-12-07

    Polyploidy is a prominent and significant force in plant evolution, taking place since ancient times and continuing until today. Recent cytogenetic studies in the genus Brachiaria using germplasm collected from wild African savannas in the 1980s revealed that most species and accessions within species are polyploid. Diploid, tetraploid, and pentaploid accessions have been found. We found asynchronous meiosis during microsporogenesis, followed by genome elimination, in two pentaploid (2n = 5x = 45) accessions (D53 and D71) of a hardy, invasive pasture grass, introduced from Africa to Brazil, Brachiaria decumbens. In these accessions, chromosomes paired as 18 bivalents and nine univalents during diakinesis, suggesting that these accessions resulted from a recent event of natural hybridization. The lack of chromosome associations in the genomes suggests that these accessions resulted from hybridization between two genotypes that are not closely related, with low genome affinity and with different meiotic rhythms. This supposition is reinforced by the meiotic behavior of the nine univalents, which were always laggard in relation to the other chromosomes and eliminated as micronuclei in microspores. The behavior of these accessions, which have an odd level of ploidy and confirmed genome elimination, supports the general assumption that a polyploid accession can undergo a new event of polyploidization by natural hybridization (neopolyploidyzation). This evidence for natural hybridization in Brachiaria shows that this is a wild genus in an ongoing evolutionary process.

  11. Salt stress response and proline accumulation in Brachiaria humidicola plants with and without mycorrhizal inoculation.

    PubMed

    Mergulhão, A C Do Espírito Santo; Burity, H A; Tabosa, J N; Figueiredo, M B Do Vale; Da Silva, M L R Bastos

    2002-01-01

    The work was carried out to investigate the effects of different concentrations of NaCl on Brachiaria humidicola Rendle in the presence and absence of Glomus etunicatum Becker and Gerdemann, as well as to evaluate some growth parameters and the accumulation of free proline in the plant leaves. The soil used was a Neosoil Fluvic Eutrophic with pH of 6.5, organic matter, 12.8 g kg-1 and soil texture, sandy loam, in which Brachiaria humidicola Rendle cv. 409 was grown. Five NaCl concentrations were tested 0; 0.22; 1.09; 1.96 and 2.84 g. kg-1 of soil, whose electrical conductivity (EC) were 2.22; 4.00; 8.13; 12.53 and 16.50 dS m-1, respectively. Brachiaria humidicola showed salt tolerance when submitted to an EC of 4 dS m-1. There was a reduction of leaf area, dry matter of shoots and roots for the soil treatments beyond EC at 8 dS m-1. Free proline content in the leaves increased together with the increase in soil salinity (EC at 8 dS m-1) demonstrating that plants submitted to EC of 2 and 4 dS m-1 were less affected by salt stress, and consequently accumulated less proline in the leaves. Root colonization was not affected by the increase of NaCl dosage in the soil.

  12. Chromosomal distribution and evolution of abundant retrotransposons in plants: gypsy elements in diploid and polyploid Brachiaria forage grasses.

    PubMed

    Santos, Fabíola Carvalho; Guyot, Romain; do Valle, Cacilda Borges; Chiari, Lucimara; Techio, Vânia Helena; Heslop-Harrison, Pat; Vanzela, André Luís Laforga

    2015-09-01

    Like other eukaryotes, the nuclear genome of plants consists of DNA with a small proportion of low-copy DNA (genes and regulatory sequences) and very abundant DNA sequence motifs that are repeated thousands up to millions of times in the genomes including transposable elements (TEs) and satellite DNA. Retrotransposons, one class of TEs, are sequences that amplify via an RNA intermediate and reinsert into the genome, are often the major fraction of a genome. Here, we put research on retrotransposons into the larger context of plant repetitive DNA and genome behaviour, showing features of genome evolution in a grass genus, Brachiaria, in relation to other plant species. We show the contrasting amplification of different retroelement fractions across the genome with characteristics for various families and domains. The genus Brachiaria includes both diploid and polyploid species, with similar chromosome types and chromosome basic numbers x = 6, 7, 8 and 9. The polyploids reproduce asexually and are apomictic, but there are also sexual species. Cytogenetic studies and flow cytometry indicate a large variation in DNA content (C-value), chromosome sizes and genome organization. In order to evaluate the role of transposable elements in the genome and karyotype organization of species of Brachiaria, we searched for sequences similar to conserved regions of TEs in RNAseq reads library produced in Brachiaria decumbens. Of the 9649 TE-like contigs, 4454 corresponded to LTR-retrotransposons, and of these, 79.5 % were similar to members of the gypsy superfamily. Sequences of conserved protein domains of gypsy were used to design primers for producing the probes. The probes were used in FISH against chromosomes of accesses of B. decumbens, Brachiaria brizantha, Brachiaria ruziziensis and Brachiaria humidicola. Probes showed hybridization signals predominantly in proximal regions, especially those for retrotransposons of the clades CRM and Athila, while elements of Del and Tat

  13. Agrobacterium-mediated transformation of the endophytic fungus Acremonium implicatum associated with Brachiaria grasses.

    PubMed

    Abello, Javier; Kelemu, Segenet; García, Celsa

    2008-03-01

    Acremonium implicatum is a seed-transmitted endophytic fungus that forms symbiotic associations with the economically significant tropical forage grasses, Brachiaria species. To take advantage of the endophyte's plant protective properties, we developed an efficient Agrobacterium-mediated transformation system for Acremonium implicatum, using green fluorescent protein (GFP) expression and vector pSK1019 (trpC promoter) or pCAMBIA1300 (CaMV35S promoter). We found that transformation efficiency doubled for both mycelial and conidial transformation as the co-cultivation period for Agrobacterium tumefaciens and Acremonium implicatum was increased from 48 to 72h. Significantly, optimal results were obtained for either mycelial or conidial transformation with Agrobacterium tumefaciens strain AGL-1 and vector pSK1019 under the control of the trpC promoter. However, mycelial transformation consistently generated a significantly higher number of transformants than did conidial transformation. The mitotic stability of the transferred DNA was confirmed by growing ten transformants in liquid and agar media for six generations. In all cases, resistance to the selection pressure (hygromycin B) was maintained. Fluorescence emission was retained by the transformants and also expressed in Brachiaria tissues from plants inoculated with GFP-transformed A. implicatum. This technology will help in the transfer and expression of agronomically important genes in host plants.

  14. Microsporogenesis analysis validates the use of artificially tetraploidized Brachiaria ruziziensis in breeding programs.

    PubMed

    Paula, C M P; Figueiredo, K G; Souza Sobrinho, F; Benites, F R G; Davide, L C; Techio, V H

    2016-09-19

    The genus Brachiaria contains species that have great economic importance in the Brazilian agricultural sector, as they enable cattle ranching on acid and poor soils with species that are resistant to spittlebugs and form crop-livestock-forest integration systems. The genus mainly consists of tetraploid (2n = 4x = 36) and apomictic species such as B. decumbens and B. brizantha. Sexuality is found in diploid species (2n = 2x = 18) such as B. ruziziensis. Interspecific hybridization between species of interest is possible by the artificial tetraploidization of B. ruziziensis and the subsequent hybridization with genotypes of B. brizantha and B. decumbens. Therefore, tetraploidized plants have to have normal meiosis or low rates of irregularities, as well as produce viable pollen grains. The objective of this study was to compare meiosis and pollen grain viability and morphology in artificially tetraploidized B. ruziziensis with that of descendants generated from crossing and selfing. The frequency of meiotic abnormalities ranged from 4.43 to 11%, and pollen viability ranged from 61 to 85%. Abnormalities were detected from prophase I to the tetrad stage with a variable frequency between the genotypes. The meiotic behavior of the artificially tetraploidized plants was little affected, and the pollen viability of the genotypes was high. Regarding pollen grain ultrastructure, there were no variations or morphological changes in the different genotypes. The genotypes have meiotic stability and high pollen viability, and can be incorporated into Brachiaria breeding programs.

  15. Desynapsis and precocious cytokinesis in Brachiaria humidicola (Poaceae) compromise meiotic division.

    PubMed

    Calisto, Vergílio; Fuzinatto, Veridiana Aparecida; Message, Hugo José; Mendes-Bonato, Andréa Beatriz; Boldrini, Kellen Regina; Pagliarini, Maria Suely; do Valle, Cacilda Borges

    2008-04-01

    The forage grass species Brachiaria humidicola is native to African savannas. Owing to its good adaptation to poorly drained and infertile acid soils, it has achieved wide utilization for pastures in Brazilian farms. Among the 55 accessions of B. humidicola analysed from the Embrapa Beef Cattle collection, one (H022), presented desynapsis and an abnormal pattern of cytokinesis in the first meiotic division. Among 28 inflorescences analysed in this accession, 12 were affected by the anomaly. In affected meiocytes, the first cytokinesis occurred in metaphase I and was generally perpendicular to a wide-metaphase plate, dividing the genome into two parts with an equal or unequal number of chromosomes. The normal cytokinesis after telophase I did not occur, and the meiocytes entered metaphase II, progressing to the end of meiosis with the occurrence of the second cytokinesis. As the first cytokinesis occurred precociously, whereas the second was normal, tetrads were formed but with unbalanced chromosome numbers in microspores. Abnormal cytokinesis occurred only in those meiocytes that underwent desynapsis after diakinesis. The implications of this abnormality in the Brachiaria breeding programme are discussed.

  16. Meiotic behavior in nonaploid accessions of Brachiaria humidicola (Poaceae) and implications for breeding.

    PubMed

    Boldrini, K R; Adamowski, E V; Silva, N; Pagliarini, M S; Valle, C B

    2011-02-01

    Brachiaria humidicola is a grass adapted to seasonally swampy grasslands in Africa; two cultivars, 'common' and Llanero, are widely used in Brazilian pastures. New cultivars are in great demand in order to diversify current production systems to achieve improved quality and yield. Cytological analyses of 55 accessions of this species available from the Embrapa Beef Cattle germplasm collection revealed that 27 are apomictic and have 2n = 54 chromosomes. Chromosome pairing as bi- to nonavalent associations at diakinesis indicated a basic chromosome number in this species of x = 6, as found in other closely related Brachiaria species. Thus, these 27 accessions are nonaploid (2n = 9x = 54). Abnormalities were found in the meiosis of these accessions, at variable frequencies. The most common abnormalities were those related to irregular chromosome segregation, which led to unbalanced gamete formation; but chromosome stickiness, cell fusion, and absence of cytokinesis were also recorded. Although some accessions have a low frequency of meiotic abnormalities, ensuring potentially good pollen viability, these cannot be used in hybridization due to a lack of sexual accessions with the same ploidy level.

  17. Origin of a polyploid accession of Brachiaria humidicola (Poaceae: Panicoideae: Paniceae).

    PubMed

    Boldrini, K R; Micheletti, P L; Gallo, P H; Mendes-Bonato, A B; Pagliarini, M S; Valle, C B

    2009-07-28

    Brachiaria humidicola, a species adapted to poorly drained and infertile acid soils, is widely used throughout the tropics. Cytological characterization of 54 accessions of B. humidicola for breeding purposes revealed 2n = 36, 42, and 54 chromosomes. One accession (H030), with 2n = 42 chromosomes, showed a different meiotic behavior. In most accessions from the genus Brachiaria previously studied, the basic chromosome number is x = 9, but the putative basic number in H030 appears to be x = 6. Since six univalent chromosomes were found in diakinesis and metaphase I, and these behaved as laggards in anaphase I, it was hypothesized that both genitors were derived from x = 6, and that this accession is a heptaploid 2n = 7x = 42. The parental genomes did not have the same meiotic behavior, particularly during anaphase, when one genome consisting of six univalents remained as laggards and underwent sister-chromatid segregation. At telophase, 18 segregated chromosomes were found at each pole. The laggard genome did not reach the poles at telophase I or II in time to be included in the nucleus and was eliminated as micronuclei.

  18. Seasonal dynamics of cyathostomin (Nematoda - Cyathostominae) infective larvae in Brachiaria humidicola grass in tropical southeast Brazil.

    PubMed

    dos Santos, Claudia N; de Souza, Luciene S; Quinelato, Simone B; do Couto, Melissa C M; Pinheiro, Jairo; Rodrigues, M Lurdes de A

    2011-08-25

    The ecology of cyathostomin larvae was evaluated in different seasons, from July 2007 to June 2008, in the municipality of Seropédica, Rio de Janeiro state, southeastern Brazil. Samples of feces and grass were collected every 15 days at 8 AM and 5 PM and the infective larvae were recovered by the Baermann technique. Leaves of the grass Brachiaria humidicola were cut to 20 cm, which is the length containing most of the larvae. The highest number of larvae was recorded at 8 AM the winter (8300 L(3)kg(-1)dm) and spring (5300 L(3)kg(-1)dm). These results demonstrate that climate conditions can affect the recovery of larvae and that rain and temperature contributed to the migration and survival of the larvae, which were available throughout the year in the study area.

  19. Nitrification Inhibitors from the root tissues of Brachiaria humidicola, a tropical grass.

    PubMed

    Gopalakrishnan, Subramaniam; Subbarao, Guntur V; Nakahara, Kazuhiko; Yoshihashi, Tadashi; Ito, Osamu; Maeda, Ikuko; Ono, Hiroshi; Yoshida, Mitsuru

    2007-02-21

    Nitrification inhibitory activity was found in root tissue extracts of Brachiaria humidicola, a tropical pasture grass. Two active inhibitory compounds were isolated by activity-guided fractionation, using recombinant Nitrosomonas europaea containing luxAB genes derived from the bioluminescent marine gram-negative bacterium Vibrio harveyi. The compounds were identified as methyl-p-coumarate and methyl ferulate, respectively. Their nitrification inhibitory properties were confirmed in chemically synthesized preparations of each. The IC50 values of chemically synthesized preparations were 19.5 and 4.4 microM, respectively. The ethyl, propyl, and butyl esters of p-coumaric and ferulic acids inhibited nitrification, whereas the free acid forms did not show inhibitory activity.

  20. Chromosome numbers and meiotic analysis in the pre-breeding of Brachiaria decumbens (Poaceae).

    PubMed

    Ricci, Gléia Cristina Laverde; De Souza-Kaneshima, Alice Maria; Felismino, Mariana Ferrari; Mendes-Bonato, Andrea Beatriz; Pagliarini, Maria Suely; Do Valle, Cacilda Borges

    2011-08-01

    A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented 2n = 18; 27 accessions, 2n = 36; and 2 accessions, 2n = 45 chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions.

  1. A Parthenogenesis Gene Candidate and Evidence for Segmental Allopolyploidy in Apomictic Brachiaria decumbens

    PubMed Central

    Worthington, Margaret; Heffelfinger, Christopher; Bernal, Diana; Quintero, Constanza; Zapata, Yeny Patricia; Perez, Juan Guillermo; De Vega, Jose; Miles, John; Dellaporta, Stephen; Tohme, Joe

    2016-01-01

    Apomixis, asexual reproduction through seed, enables breeders to identify and faithfully propagate superior heterozygous genotypes by seed without the disadvantages of vegetative propagation or the expense and complexity of hybrid seed production. The availability of new tools such as genotyping by sequencing and bioinformatics pipelines for species lacking reference genomes now makes the construction of dense maps possible in apomictic species, despite complications including polyploidy, multisomic inheritance, self-incompatibility, and high levels of heterozygosity. In this study, we developed saturated linkage maps for the maternal and paternal genomes of an interspecific Brachiaria ruziziensis (R. Germ. and C. M. Evrard) × B. decumbens Stapf. F1 mapping population in order to identify markers linked to apomixis. High-resolution molecular karyotyping and comparative genomics with Setaria italica (L.) P. Beauv provided conclusive evidence for segmental allopolyploidy in B. decumbens, with strong preferential pairing of homologs across the genome and multisomic segregation relatively more common in chromosome 8. The apospory-specific genomic region (ASGR) was mapped to a region of reduced recombination on B. decumbens chromosome 5. The Pennisetum squamulatum (L.) R.Br. PsASGR-BABY BOOM-like (psASGR–BBML)-specific primer pair p779/p780 was in perfect linkage with the ASGR in the F1 mapping population and diagnostic for reproductive mode in a diversity panel of known sexual and apomict Brachiaria (Trin.) Griseb. and P. maximum Jacq. germplasm accessions and cultivars. These findings indicate that ASGR–BBML gene sequences are highly conserved across the Paniceae and add further support for the postulation of the ASGR–BBML as candidate genes for the apomictic function of parthenogenesis. PMID:27206716

  2. Development and validation of microsatellite markers for Brachiaria ruziziensis obtained by partial genome assembly of Illumina single-end reads

    PubMed Central

    2013-01-01

    Background Brachiaria ruziziensis is one of the most important forage species planted in the tropics. The application of genomic tools to aid the selection of superior genotypes can provide support to B. ruziziensis breeding programs. However, there is a complete lack of information about the B. ruziziensis genome. Also, the availability of genomic tools, such as molecular markers, to support B. ruziziensis breeding programs is rather limited. Recently, next-generation sequencing technologies have been applied to generate sequence data for the identification of microsatellite regions and primer design. In this study, we present a first validated set of SSR markers for Brachiaria ruziziensis, selected from a de novo partial genome assembly of single-end Illumina reads. Results A total of 85,567 perfect microsatellite loci were detected in contigs with a minimum 10X coverage. We selected a set of 500 microsatellite loci identified in contigs with minimum 100X coverage for primer design and synthesis, and tested a subset of 269 primer pairs, 198 of which were polymorphic on 11 representative B. ruziziensis accessions. Descriptive statistics for these primer pairs are presented, as well as estimates of marker transferability to other relevant brachiaria species. Finally, a set of 11 multiplex panels containing the 30 most informative markers was validated and proposed for B. ruziziensis genetic analysis. Conclusions We show that the detection and development of microsatellite markers from genome assembled Illumina single-end DNA sequences is highly efficient. The developed markers are readily suitable for genetic analysis and marker assisted selection of Brachiaria ruziziensis. The use of this approach for microsatellite marker development is promising for species with limited genomic information, whose breeding programs would benefit from the use of genomic tools. To our knowledge, this is the first set of microsatellite markers developed for this important species

  3. Hepatic photosensitization in buffaloes intoxicated by Brachiaria decumbens in Minas Gerais state, Brazil.

    PubMed

    De Oliveira, C H S; Barbosa, J D; Oliveira, C M C; Bastianetto, E; Melo, M M; Haraguchi, M; Freitas, L G L; Silva, M X; Leite, R C

    2013-10-01

    The aim of this paper is to report the study of hepatogenous photosensitization in buffaloes during two outbreaks provoked by ingestion of Brachiaria decumbens in Minas Gerais state, Brazil. Ten young buffaloes in outbreak 1 and seven buffaloes in outbreak 2 were intoxicated by B. decumbens. Nine clinically healthy buffaloes raised under the same conditions as the sick animals served as the control group. All animals were subjected to clinical examination, and serum was collected to measure gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), direct bilirubin (DB), indirect bilirubin (IB) and total bilirubin (TB) as indicators of liver function and urea and creatinine as indicators of renal function. Histopathology of liver fragments from five different animals was carried out. During the outbreaks and every two months for one year, samples of grass from paddocks where the animals got sick were collected for quantitative evaluation of the saponin protodioscin, combined with observations of pasture characteristics and daily rainfall. Clinical signs included apathy, weight loss, restlessness, scar retraction of the ears and intense itching at the skin lesions, mainly on the rump, the tail head, neck and hindlimbs, similar to the signs observed in other ruminants. Only the GGT enzyme presented significantly different (P < 0.01) serum levels between intoxicated animals (n = 17) and healthy animals (n = 9), indicating liver damage in buffaloes bred in B. decumbens pastures. Microscopy of the liver showed foamy macrophages and lesions of liver disease associated with the presence of crystals in the bile ducts, which have also been found in sheep and cattle poisoned by grasses of the genus Brachiaria. During the outbreaks, protodioscin levels were higher than 3%, and shortly after, these levels were reduced to less than 0.80%, suggesting a hepatic injury etiology. The outbreaks took place at the beginning of the rainy season, and there was a positive

  4. Inclusion of Tithonia diversifolia in multinutrient blocks for WestAfrican dwarf goats fed Brachiaria straw.

    PubMed

    Tendonkeng, Fernand; Fogang Zogang, Bienvenu; Sawa, Camara; Boukila, Benoît; Pamo, Etienne Tedonkeng

    2014-08-01

    Recent investigations suggest that the development of multinutrient feed blocks with inclusion of tree and shrub leaves could improve the nutritive value and digestibility of straw. In order to test these possibilities, three types of multinutrient blocks (MNB) namely: MNB0 (wheat bran = 100%; Tithonia diversifolia leaf = 0%), MNB50 (wheat bran = 50%; T. diversifolia leaf = 50%) and MNB100 (wheat bran = 0%; T. diversifolia leaf = 100%) were fed for 15 days in a 3 × 3 Latin square arrangement to West African dwarf goats consuming Brachiaria ruziziensis straw. The blocks presented a good cohesion and a good hardness. The inclusion of T. diversifolia improved levels of crude protein, mineral, feed unit for milk production (UFL) and feed unit for meat production (UFV), but decreased palatability. The effects on the digestibility of B. ruziziensis straw were evaluated in nine West African dwarf goats fed individually with MNB0 + straw, MNB50 + straw and MNB100 + straw. The dry matter, organic matter and crude fibre digestibility of B. ruziziensis straw increased slightly with increasing level of inclusion of T. diversifolia. The apparent digestibility of nitrogen was comparable for all diets independent of the level of inclusion of T. diversifolia. This study showed that the inclusion of T. diversifolia leaves in the MNBs can be recommended to improve the feeding of goats during periods of drought.

  5. Roasted soybean supplements for finishing beef cattle on Brachiaria brizantha pasture.

    PubMed

    de Oliveira, André Alves; Tilemahos Zervoudakis, Joanis; Hatamoto-Zervoudakis, Luciana Keiko; da Silva Cabral, Luciano; da Silva-Marques, Renata Pereira; Koscheck, Jeferson Fabiano Werner; Guedes de Carvalho, Daniel Marino; Benatti, João Marcos Beltrame; Alonso, Marcella Katherine

    2015-10-01

    Two experiments were conducted to evaluate the inclusion of 0, 14, 27.5 and 41 g/kg roasted soybean (RSB) in protein-energy supplements for the finishing of beef cattle on pastures of Brachiaria brizantha cv. Marandu in the rainy period. In experiment 1, for the evaluation of the nutritional parameters, five rumen-cannulated steers with an initial average body weight of 474.5 kg were utilised. In experiment 2, for the evaluation of performance, 25 intact male zebu cattle with an initial average body weight of 418 kg were utilised. Supply of RSB led to an increase in the intake of crude protein and non-fibre carbohydrates (P < 0.05). The concentrations of rumen ammonia nitrogen increased significantly (P < 0.05) 4 h after supplementation. The animals that received protein-energy supplements had superior (52 %) average daily gain in relation to those receiving mineral mixture. The supply of protein-energy supplements formulated with roasted soybean provided an increase in average daily weight gain and an improvement in the nutritional parameters of finishing beef cattle on pasture in the rainy period.

  6. Cyathostomin larvae: presence on Brachiaria humidicola grass during the rainy and dry seasons of Brazil.

    PubMed

    dos Santos, Claudia Navarro; de Souza, Luciene Soares; Vieira, Vivian Suane de Freitas; Pinheiro, Jairo; Rodrigues, Maria de Lurdes de Azevedo

    2012-01-01

    The presence of cyathostomin larvae is directly associated to climatic conditions of each region. This study aimed to evaluate the ecology of infective larvae on Brachiaria humidicola during the dry and rainy seasons from October 2007 to September 2008 in a tropical region, Rio de Janeiro state, southeastern Brazil. Stools were collected from the rectum of horses naturally infected with cyathostomins at the beginning of the rainy season (October to March) and dry season (April to September). They were divided into four samples of 500 g and deposited on a grass patch of B. humidicola. Seven days later and every 15 days thereafter samples of feces and grass were collected and processed by the Baermann technique. The mean number of larvae recovered from the grass varied according to the season, with greater recovery of larvae during the peak of the dry season (14,700 L3.kg-¹ DM). There was a statistically significant difference between L3 recovered from feces and grass, but not between L3 recovered from the grass base and apex. These results show that the region's climate favors the development and survival of infective cyathostomin larvae throughout the year, with a greater number of larvae during the dry season.

  7. RFLP mapping of a Hordeum bulbosum gene highly expressed in pistils and its relationship to homoeologous loci in other Gramineae species.

    PubMed

    Gudu, S.; Laurie, A.; Kasha, J.; Xia, J.; Snape, W.

    2002-08-01

    A cDNA sequence (Hbc8-2) isolated from pistils of the self-incompatible species Hordeum bulbosum was analysed for expression pattern and genetic map location. Hbc8-2 was expressed just prior to anthesis in mature pistils, and expression was maintained at a high level throughout anthesis. The same expression pattern was found in self-incompatible rye ( Secale cereale), but no expression was detected in the self-compatible cereals wheat ( Triticum aestivum) or barley ( Hordeum vulgare) at comparable stages of development. However, three wheat expressed sequence tags from a pre-anthesis library had high homology to Hbc8-2. Southern blot analyses using Hbc8-2 as a probe detected hybridising bands in the genomes of various Gramineae species including rye, barley, bread wheat, wild wheat relatives ( Aegilops tauschii and Ae. speltoides), oats ( Avena fatua and A. strigosa), rice ( Oryza sativa) and maize ( Zea mays). This suggests that Hbc8-2-like sequences are present in many species but that high levels of expression may be associated with self-incompatibility. Hbc8-2 was mapped on the long arms of chromosome 2H(b) of H. bulbosum, 2R of rye, and 2B and 2D of wheat and was assigned to chromosome 2H of barley using wheat/barley addition lines. On a H. bulbosum genetic map, Xhbc8-2 was located between Xbcd266 and Xpsr87, while in rye and wheat it was located in a 13.2-cM interval between Xpsr331 and Xpsr932, consistent with previous comparative mapping studies of these species. Mapping in rye suggested that Hbc8-2 is probably proximal to the Z self-incompatibility locus which was previously shown to be tightly linked to Xbcd266.

  8. The perennial pattern of clinical symptoms in children monosensitized to Olea europaea pollen allergens in comparison with subjects with Parietaria and Gramineae pollinosis.

    PubMed

    Liccardi, G; Russo, M; Piccolo, A; Lobefalo, G; Salzillo, A; D'Amato, M; D'Amato, G

    1997-01-01

    Because the pediatric age represents a good model to study the correlation between the exposure to allergens and development of respiratory allergy, we investigated the occurrence of a perennial type of symptomatology in children monosensitized to Olea europaea (O.e.) pollen allergens compared with subjects with monosensitization to Parietaria (P) and Gramineae (G) in order to confirm our previous observations in adults. We selected a group of 52 children with rhinitis and/or bronchial asthma and a SPT positivity only to pollens (30 to P, 15 to G, and 7 to O.e.). Using commercially available allergenic extracts and reagents, the following diagnostic procedures were performed: skin prick test (SPT), specific IgE assays (RAST), nonspecific bronchial provocation test (NsBPT) and specific nasal provocation test (sNPT), respectively, in patients with bronchial asthma and rhinitis. Pollen counts and a statistical analysis using Spearman's correlation test were also carried out. Six of seven children with monosensitization to O.e. allergens showed a perennial pattern of symptoms in comparison to 7 of 23 and 3 of 12, respectively, in subjects with P and G pollinosis. All patients with perennial nasal symptoms of O.e. group exhibited a late nasal response after sNPT. Although these findings on nasal response may partially explain the occurrence of a prolonged inflammation of the nose induced by O.e. allergens, we think that other possibilities could be investigated. In our opinion, further studies are necessary using better purified and standardized diagnostic materials and, moreover, a greater number of O.e. monosensitized children living in other geographical areas need to be examined for a comparison of our results with theirs.

  9. Phytotoxic substances with allelopathic activity may be central to the strong invasive potential of Brachiaria brizantha.

    PubMed

    Kato-Noguchi, Hisashi; Kobayashi, Ai; Ohno, Osamu; Kimura, Fukiko; Fujii, Yoshiharu; Suenaga, Kiyotake

    2014-04-15

    The grass Brachiaria brizantha, native to eastern Africa, becomes naturalized and dominant quickly in the non-native areas. It was hypothesized that phytotoxic chemical interaction between this plant and native plants may play an important role in the invasion of B. brizantha. However, no potent phytotoxic substance has been reported in this species. Therefore, we investigated possible allelopathic activity and searched for phytotoxic substances with allelopathic activity in B. brizantha. An aqueous methanol extract of B. brizantha inhibited the growth of roots and shoots of garden cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was purified by several chromatographic runs and three allelopathically active substances were isolated and identified by spectral analysis as (6R,9R)-3-oxo-α-ionol, (6R,9S)-3-oxo-α-ionol and 4-ketopinoresinol. (6R,9R)-3-Oxo-α-ionol and (6R,9S)-3-oxo-α-ionol inhibited root and shoot growth of garden cress at concentrations greater than 30 and 10 μM, respectively. The activity of (6R,9S)-3-oxo-α-ionol was 5.3- to 6.2-fold that of (6R,9R)-3-oxo-α-ionol. The stereochemistry of the hydroxyl group at position C-9 may be important for the inhibitory activities of those compounds. 4-Ketopinoresinol inhibited root and shoot growth of garden cress at concentrations greater than 30 μM. The growth inhibitory activity of (6R,9S)-3-oxo-α-ionol was the greatest and followed by 4-ketopinoresinol and (6R,9R)-3-oxo-α-ionol. These results suggest that those phytotoxic substances may contribute to the allelopathic effect caused by B. brizantha and may be involved in the invasion of B. brizantha.

  10. Ingestive Behavior of Heifers Supplemented with Glycerin in Substitution of Corn on Brachiaria brizantha Pasture

    PubMed Central

    Facuri, L. M. A. M.; Silva, R. R.; da Silva, F. F.; de Carvalho, G. G. P.; Sampaio, C. B.; Mendes, F. B. L.; Lisboa, M. M.; Barroso, D. S.; Carvalho, V. M.; Pereira, M. M. S.

    2014-01-01

    The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%), 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p<0.05), whereas the time spent on activities like rumination, idleness, trough and total chewing time were quadratically affected (p<0.05). Bite rate and number of bites/day were quadratically influenced (p<0.05). The number of bites/swallowed cud and the number of bites/minute, however, increased linearly (p<0.05). Although the time spent on each cud and number of chews per cud were not affected (p>0.05). The number of rumination periods reduced linearly (p<0.05), whereas the number of grazing, idle and trough periods, and the times per grazing, idle, rumination and trough periods were quadratically affected (p<0.05). The feed and rumination efficiencies of the dry matter, non-fibrous carbohydrates, pasture dry matter and concentrate were quadratically affected (p>0.05) whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05). Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies. PMID:25358318

  11. Expressed sequence-tag analysis of ovaries of Brachiaria brizantha reveals genes associated with the early steps of embryo sac differentiation of apomictic plants.

    PubMed

    Silveira, Erica Duarte; Guimarães, Larissa Arrais; de Alencar Dusi, Diva Maria; da Silva, Felipe Rodrigues; Martins, Natália Florencio; do Carmo Costa, Marcos Mota; Alves-Ferreira, Márcio; de Campos Carneiro, Vera Tavares

    2012-02-01

    In apomixis, asexual mode of plant reproduction through seeds, an unreduced megagametophyte is formed due to circumvented or altered meiosis. The embryo develops autonomously from the unreduced egg cell, independently of fertilization. Brachiaria is a genus of tropical forage grasses that reproduces sexually or by apomixis. A limited number of studies have reported the sequencing of apomixis-related genes and a few Brachiaria sequences have been deposited at genebank databases. This work shows sequencing and expression analyses of expressed sequence-tags (ESTs) of Brachiaria genus and points to transcripts from ovaries with preferential expression at megasporogenesis in apomictic plants. From the 11 differentially expressed sequences from immature ovaries of sexual and apomictic Brachiaria brizantha obtained from macroarray analysis, 9 were preferentially detected in ovaries of apomicts, as confirmed by RT-qPCR. A putative involvement in early steps of Panicum-type embryo sac differentiation of four sequences from B. brizantha ovaries: BbrizHelic, BbrizRan, BbrizSec13 and BbrizSti1 is suggested. Two of these, BbrizSti1 and BbrizHelic, with similarity to a gene coding to stress induced protein and a helicase, respectively, are preferentially expressed in the early stages of apomictic ovaries development, especially in the nucellus, in a stage previous to the differentiation of aposporous initials, as verified by in situ hybridization.

  12. Brachiaria ruziziensis Responses to Different Fertilization Doses and to the Attack of Mahanarva spectabilis (Hemiptera: Cercopidae) Nymphs and Adults

    PubMed Central

    Aguiar, Daniela de Melo; Auad, Alexander Machado; Fonseca, Marcy das Graças; Leite, Melissa Vieira

    2014-01-01

    Cropping practices are necessary in order to help reduce the population of pest insect, such as the induction of resistance through fertilization. Therefore, this study aimed to assess alterations on the production and quality of Brachiaria ruziziensis when receiving the fertilization composed by the macronutrients NPK and/or exposed to the attack of Mahanarva spectabilis nymphs and adults. B. ruziziensis plants were fertilized according to the recommendation (R), half of the recommended fertilization (H), or non-fertilization (C). They were also exposed to different M. spectabilis nymph and adult densities. The damage, regrowth, and bromatological components were evaluated. The fertilization treatment promoted a higher M. spectabilis nymph survival on B. ruziziensis; however, it reduced the damage caused by the forage exposed to nymphs and adults of pest insect, and it did not alter the quality of the signal grass. Moreover, the fertilization treatment enabled forage recovery, even when exposed to 5 nymphs or 10 spittlebug adults. PMID:24578645

  13. Meiotic behaviour in three interspecific three-way hybrids between Brachiaria ruziziensis and B. brizantha (Poaceae: Paniceae).

    PubMed

    Adamowski, Eleniza de Victor; Pagliarini, Maria Suely; do Valle, Cacilda Borges

    2008-04-01

    The meiotic behaviour of three three-way interspecific promising hybrids (H17, H27, and H34) was evaluated. These hybrids resulted from the crosses between B. ruziziensis X B. brizantha and crossed to another B. brizantha. Two half-sib hybrids (H27 and H34) presented an aneuploid chromosome number (2n = 4x = 33), whereas hybrid H17 was a tetraploid (2n = 4x = 36), as expected. Chromosome paired predominantly as multivalents suggesting that genetic recombination and introgression of specific target genes from B. brizantha into B. ruziziensis can be expected. Arrangement of parental genomes in distinct metaphase plates was observed in H27 and H34, which have different male genitors. Hybrids H17 and H34 have the same male genitor, but did not display this abnormality. In H17, abnormalities were more frequent from anaphase II, when many laggard chromosomes appeared, suggesting that each genome presented a different genetic control for meiotic phase timing. Despite the phylogenetic proximity among these two species, these three hybrids presented a high frequency of meiotic abnormalities, mainly those related to irregular chromosome segregation typical of polyploids, H34, 69.1%; H27, 56.1% and H17, 44.9%. From the accumulated results obtained through cytological studies in Brachiaria hybrids, it is evident that cytogenetical analysis is of prime importance in determining which genotypes can continue in the process of cultivar development and which can be successfully used in the breeding. Hybrids with high frequency of meiotic abnormalities can seriously compromise seed production, a key trait in assuring adoption of a new apomictic cultivar of Brachiaria for pasture formation.

  14. Waterlogging-induced changes in root architecture of germplasm accessions of the tropical forage grass Brachiaria humidicola.

    PubMed

    Cardoso, Juan Andrés; Jiménez, Juan de la Cruz; Rao, Idupulapati M

    2014-04-08

    Waterlogging is one of the major factors limiting the productivity of pastures in the humid tropics. Brachiaria humidicola is a forage grass commonly used in zones prone to temporary waterlogging. Brachiaria humidicola accessions adapt to waterlogging by increasing aerenchyma in nodal roots above constitutive levels to improve oxygenation of root tissues. In some accessions, waterlogging reduces the number of lateral roots developed from main root axes. Waterlogging-induced reduction of lateral roots could be of adaptive value as lateral roots consume oxygen supplied from above ground via their parent root. However, a reduction in lateral root development could also be detrimental by decreasing the surface area for nutrient and water absorption. To examine the impact of waterlogging on lateral root development, an outdoor study was conducted to test differences in vertical root distribution (in terms of dry mass and length) and the proportion of lateral roots to the total root system (sum of nodal and lateral roots) down the soil profile under drained or waterlogged soil conditions. Plant material consisted of 12 B. humidicola accessions from the gene bank of the International Center for Tropical Agriculture, Colombia. Rooting depth was restricted by 21 days of waterlogging and confined to the first 30 cm below the soil surface. Although waterlogging reduced the overall proportion of lateral roots, its proportion significantly increased in the top 10 cm of the soil. This suggests that soil flooding increases lateral root proliferation of B. humidicola in the upper soil layers. This may compensate for the reduction of root surface area brought about by the restriction of root growth at depths below 30 cm. Further work is needed to test the relative efficiency of nodal and lateral roots for nutrient and water uptake under waterlogged soil conditions.

  15. Waterlogging-induced changes in root architecture of germplasm accessions of the tropical forage grass Brachiaria humidicola

    PubMed Central

    Cardoso, Juan Andrés; Jiménez, Juan de la Cruz; Rao, Idupulapati M.

    2014-01-01

    Waterlogging is one of the major factors limiting the productivity of pastures in the humid tropics. Brachiaria humidicola is a forage grass commonly used in zones prone to temporary waterlogging. Brachiaria humidicola accessions adapt to waterlogging by increasing aerenchyma in nodal roots above constitutive levels to improve oxygenation of root tissues. In some accessions, waterlogging reduces the number of lateral roots developed from main root axes. Waterlogging-induced reduction of lateral roots could be of adaptive value as lateral roots consume oxygen supplied from above ground via their parent root. However, a reduction in lateral root development could also be detrimental by decreasing the surface area for nutrient and water absorption. To examine the impact of waterlogging on lateral root development, an outdoor study was conducted to test differences in vertical root distribution (in terms of dry mass and length) and the proportion of lateral roots to the total root system (sum of nodal and lateral roots) down the soil profile under drained or waterlogged soil conditions. Plant material consisted of 12 B. humidicola accessions from the gene bank of the International Center for Tropical Agriculture, Colombia. Rooting depth was restricted by 21 days of waterlogging and confined to the first 30 cm below the soil surface. Although waterlogging reduced the overall proportion of lateral roots, its proportion significantly increased in the top 10 cm of the soil. This suggests that soil flooding increases lateral root proliferation of B. humidicola in the upper soil layers. This may compensate for the reduction of root surface area brought about by the restriction of root growth at depths below 30 cm. Further work is needed to test the relative efficiency of nodal and lateral roots for nutrient and water uptake under waterlogged soil conditions. PMID:24876299

  16. [Morphological and molecular identification of Prosapia simulans (Walker) (Hemiptera: Cercopidae), and screening and mechanisms of resistance to this spittlebug in Brachiaria hybrids].

    PubMed

    Castro, Ulises; Cardona, Cesar; Vera-Graziano, Jorge; Miles, John; Garza-Garcia, Ramón

    2007-01-01

    Prosapia simulans (Walker) is an important spittlebug species that attacks forage grasses of the genus Brachiaria (Trin.) Griseb. from Mexico to Colombia. This, and several other species of spittlebugs, cause important economic losses to the livestock production industry. Development of resistant cultivars is regarded as the best method of control. In the present study we used taxonomic keys, dissection of male genitalia and RAPD-PCR patterns to reconfirm the identity of P. simulans specimens collected in Colombia and Mexico. We were able to reconfirm that P. simulans occurs as a pest of Brachiaria from Mexico to Colombia. We also studied the levels and mechanisms of resistance present in 34 Brachiaria hybrids developed by CIAT. Infestations were made with six eggs per plant. We used 10 replications (plants) per genotype in a completely randomized design. Seven hybrids were found to be susceptible, 16 showed intermediate resistance and 11 were resistant. Antibiosis was the mechanism of resistance expressed in resistant hybrids as well as in the resistant checks CIAT 6294 and CIAT 36062. Tolerance was absent. The genotypes BRX 4402 and CIAT 0606 were classified as highly susceptible.

  17. Genetic diversity and population structure analysis of the tropical pasture grass Brachiaria humidicola based on microsatellites, cytogenetics, morphological traits, and geographical origin.

    PubMed

    Jungmann, L; Vigna, B B Z; Boldrini, K R; Sousa, A C B; do Valle, C B; Resende, R M S; Pagliarini, M S; Zucchi, M I; de Souza, A P

    2010-09-01

    Brachiaria humidicola (Rendle) Schweick. is a warm-season grass commonly used as forage in the tropics. Accessions of this species were collected in eastern Africa and massively introduced into South America in the 1980s. Several of these accessions form a germplasm collection at the Brazilian Agricultural Research Corporation. However, apomixis, ploidy, and limited knowledge of the genetic basis of this germplasm collection have constrained breeding activities. The objectives of this work were to identify genetic variability in the Brazilian B. humidicola germplasm collection using microsatellite markers and to compare the results with information on the following: (1) collection sites of the accessions; (2) reproductive mode and ploidy levels; and (3) genetic diversity revealed by morphological traits. The evaluated germplasm population is highly structured into four major groups. The sole sexual accession did not group with any of the clusters. Genetic dissimilarities did not correlate with either geographic distances or genetic distances inferred from morphological descriptors. Additionally, the genetic structure identified in this collection did not correspond to differences in ploidy level. Alleles exclusive to either sexual or apomictic accessions were identified, suggesting that further evaluation of the association of these loci with apospory should be carried out.

  18. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins

    PubMed Central

    Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

    2017-01-01

    Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin. PMID:28165411

  19. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  20. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  1. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  2. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  3. Biosynthesis and Regulation of Bioprotective Alkaloids in the Gramineae Endophytic Fungi with Implications for Herbivores Deterrents.

    PubMed

    Luo, Hongping; Xie, Longxiang; Zeng, Jie; Xie, Jianping

    2015-12-01

    Four kinds of bioprotective alkaloids-peramine, loline, ergot alkaloid, indole-diterpenes, produced by grass-fungal endophyte symbioses, are deterrents or toxic to vertebrate and invertebrate herbivores. Ergot alkaloids have pharmacological properties and widely are used clinically. The regulation of alkaloids biosynthesis is under intensive study to improve the yield for better agricultural and medicinal application. In this paper, we summarize the structure, related genes, regulation, and toxicity of alkaloids. We focus on the biosynthesis and the regulation network of alkaloids.

  4. Screening for and Inheritance of Resistance to Barley Leaf Stripe (Drechslera graminea),

    DTIC Science & Technology

    1987-12-01

    seeds inoculated between two layers of mycelium -overgrown agar plates. A new, uncommon symptom was uncovered. Absolute resistance nr immunity in the...Page 1. INTRODUCTION ......................................... 7 2. MATERIAL AND METHODS ................................. .7 3. SYMPTOMS...Discussion............................................ 68 4.2.1. The material ................................... 68 4.2.2. The significance

  5. Ultrastructure of the wild rice Oryza grandiglumis (Gramineae) in Costa Rica.

    PubMed

    Sánchez, Ethel; Quesada, Tania; Espinoza, Ana M

    2006-06-01

    Oryza grandiglumis is a wild species of rice endemic to tropical America. This species was first found in 1998 in the wetlands of Caño Negro, located in the northern part of Costa Rica. Twenty five plants of O. grandiglumis were processed for scanning electron microscope. An ultrastructural description of the leaf blade, ligule, auricles, spikelet and caryopsis, with an emphasis on structures of taxonomic value. The leaf blade has a characteristic cuticular wax pattern, composed of dense rod-like structures, and is surrounded by papillae, zipper-like silica cells, abundant bulky prickle trichomes, and hooked trichomes. The blade's edge has three rows of hooked prickle trichomes of various sizes. The auricles wrapped the culm, with long attenuated trichomes at the edges; the base was surrounded by oblong cells. The ligule is a blunt membrane covered by short prickle trichomes. Spikelet morphology is characteristic of the Poaceae family, but the sterile lemmas were nearly as long as the fertile lemmas, and they have an unique crown-like structure of lignified spines between the rachilla and the fertile lemmas. Comparison with Brazilian specimens of O. grandiglumis revealed little differences in the ultrastructural characteristics.

  6. In Vitro Mass Propagation of Cymbopogon citratus Stapf., a Medicinal Gramineae.

    PubMed

    Quiala, Elisa; Barbón, Raúl; Capote, Alina; Pérez, Naivy; Jiménez, Elio

    2016-01-01

    Cymbopogon citratus (D.C.) Stapf. is a medicinal plant source of lemon grass oils with multiple uses in the pharmaceutical and food industry. Conventional propagation in semisolid culture medium has become a fast tool for mass propagation of lemon grass, but the production cost must be lower. A solution could be the application of in vitro propagation methods based on liquid culture advantages and automation. This chapter provides two efficient protocols for in vitro propagation via organogenesis and somatic embryogenesis of this medicinal plant. Firstly, we report the production of shoots using a temporary immersion system (TIS). Secondly, a protocol for somatic embryogenesis using semisolid culture for callus formation and multiplication, and liquid culture in a rotatory shaker and conventional bioreactors for the maintenance of embryogenic culture, is described. Well-developed plants can be achieved from both protocols. Here we provide a fast and efficient technology for mass propagation of this medicinal plant taking the advantage of liquid culture and automation.

  7. Description and interpretation of the bracts epidermis of Gramineae (Poaceae) with rotated image with maximum average power spectrum (RIMAPS) technique.

    PubMed

    Favret, Eduardo A; Fuentes, Néstor O; Molina, Ana M; Setten, Lorena M

    2008-10-01

    During the last few years, RIMAPS technique has been used to characterize the micro-relief of metallic surfaces and recently also applied to biological surfaces. RIMAPS is an image analysis technique which uses the rotation of an image and calculates its average power spectrum. Here, it is presented as a tool for describing the morphology of the trichodium net found in some grasses, which is developed on the epidermal cells of the lemma. Three different species of grasses (herbarium samples) are analyzed: Podagrostis aequivalvis (Trin.) Scribn. & Merr., Bromidium hygrometricum (Nees) Nees & Meyen and Bromidium ramboi (Parodi) Rúgolo. Simple schemes representing the real microstructure of the lemma are proposed and studied. RIMAPS spectra of both the schemes and the real microstructures are compared. These results allow inferring how similar the proposed geometrical schemes are to the real microstructures. Each geometrical pattern could be used as a reference for classifying other species. Finally, this kind of analysis is used to determine the morphology of the trichodium net of Agrostis breviculmis Hitchc. As the dried sample had shrunk and the microstructure was not clear, two kinds of morphology are proposed for the trichodium net of Agrostis L., one elliptical and the other rectilinear, the former being the most suitable.

  8. Potential of Brachiaria mutica (Para grass) for bioethanol production from Loktak Lake.

    PubMed

    Sahoo, Dinabandhu; Ummalyma, Sabeela Beevi; Okram, Aswini Kumar; Sukumaran, Rajeev K; George, Emrin; Pandey, Ashok

    2017-03-12

    The aim of present study was to evaluate feasibility of using the Para grass as feedstock for production of bioethanol. Process involved the pretreatment with dilute acid or alkali and followed by enzymatic saccharification with commercial cellulase. Maximum sugar release of 696mg/g was obtained from 10% biomass loading and 0.5% w/v of alkali whereas in the case of acid pretreatment maximum sugar of 660mg/g was obtained from 20% biomass loading and 2% w/v acid loading. Results showed that Para grass utilization as a biorefinery feedstock can be a potential strategy to address the sustainable utilization of this invasive grass thereby keeping its population in check in the Loktak Lake.

  9. Indirect measurements of Brachiaria brizantha cv. Marandu fermentable cell wall sugars for second generation biofuels production.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Results of a study conducted to evaluate the possibility of using IVDMD values of B. brizantha cv. Marandu to predict cell wall sugars that would be available in a biorefinery for ethanol production are reported. The study was conducted based on the similarity between rumen enzymes and those used i...

  10. [Review on nonessential constituents of vegetables. II. Cruciferae (Brassica vegetables, radish, turnip, rutabaga, horse-radish) and gramineae (onion, leek, chive, garlic, asparagus) (author's transl)].

    PubMed

    Herrmann, K

    1977-12-09

    In this paper the hitherto known constituents of the titled vegetables except proteins, carbohydrates, triglyceride-fatty acids, and vitamins are reviewed, especially the volatiles, organic acids, phenolics, carotenoids and lipids.

  11. Soil nutrients and liming on dry weight yields and forage quality of Signal grass (Brachiaria decumbens Stapf.), grown on Korat soil series (oxic paleustults) in northeast Thailand.

    PubMed

    Pholsen, Suradej

    2010-07-01

    This experiment was carried out at Khon Kaen University Experimental Farm, Khon Kaen University, Thailand during the 2004-2005 aiming to investigate effect of phosphorus (P) and dolomite levels on dry weight yields (DWYs) and forage quality of Signal grass. A 4x3 factorial arranged in a Randomized Complete Block Design (RCBD) was used. Four P levels were: 0, 100, 200 and 400 kg P2O5 ha-1 and three dolomite levels were: 0, 625 and 2,500 kg ha-1. The Signal grass plants were grown on Korat soil series, (Oxic Paleustults). A quadrat with a dimension of 50x50 cm was used for grass yield harvests. Crude Protein (CP), Acid Detergent Fibre (ADF), Neutral Detergent Fibre (NDF) and Dry Matter Degradability (DMD) contents were determined. Tissues phosphorus and calcium contents were also analysed. The results showed that an increase in dolomite levels increased soil pH from 4.4 to 5.1 for levels 1 and 3, respectively. An increase in P levels increased available soil P from 4.56 to 28.38 ppm for levels 1 and 4, respectively. For the first year experiment, dolomite levels had no significant effect on DWYs, whilst P levels significantly increased but only up to level 2. The 2-year average DWYs reached 11,368 kg ha-1 for level 4 of P. With the first year rainy season harvests, P levels had its significant effect on ADF and DMD up to level 2 but not with CP and NDF. For the dry season harvests, P and dolomite levels had no significant effects on forage quality. Dolomite levels had no significant effect on P and Ca contents of the Signal grass tissues but an increase in P levels increased P contents. P and Ca contents, in most cases, were higher for the dry season than the rainy season.

  12. [Characteristics of stemflow for typical alpine shrubs in Qilian Mountain].

    PubMed

    Liu, Zhang-wen; Chen, Ren-sheng; Song, Yao-xuan

    2011-08-01

    Taking the typical alpine shrubs Potentilla fruticosa, Salix cupularis, Hippophae rhamnoides, and Caragana jubata in Qilian Mountain as test objects, a field investigation from June 1 to October 31, 2010 was conducted on the variation characteristics of the shrub stemflow, and analyzed the affecting effects of rainfall intensity and canopy structure morphology. The stemflow generated when the rainfall in early period was 2.1 mm, with an average of 3.4%, 3.2%, 8.0%, and 4.2% of the gross rainfall for P. fruticosa, S. cupularis, H. rhamnoides, and C. jubata, respectively. There was a significant positive linear correlation between the stemflow and rainfall intensity. With increasing rainfall, the stemflow percentage showed a trend of increase-decrease-increase. Stemflow played an important role in supplying water to the shrub rhizosphere, and the average funneling ratio was 59, 30, 110, and 49 for P. fruticosa, S. cupularis, H. rhamnoides, and C. jubata, respectively. The stemflow percentage had a significant exponential relationship with the maximum rain intensity in 10 minutes (I10). When the I10 was more than 6.0 mm x h(-1), the stemflow of H. rhamnoides and C. jubata showed a persistently increasing trend, while that of P. fruticosa and S. cupularis tended to be stable. Canopy structure morphology had complicated effects on the stemflow. In the same rainfall intensities, the height and crown projection area of the shrubs were the important factors affecting the generation of stemflow.

  13. Energy content of tropical grasses and legumes grown for bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass samples of the tropical grasses Brachiaria brizantha (Hochst. ex A. Rich.) Staph, Brachiaria humidicola (Rendle) Schweick, Brachiaria decumbens Staph, Panicum maximum Jacq., Pennistetum alopecuroides (L.) Spreng and three species of the tropical legume Stylosanthes grown in Mato Grosso do Su...

  14. Lectin cDNA and transgenic plants derived therefrom

    DOEpatents

    Raikhel, Natasha V.

    2000-10-03

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties.

  15. Construction of New Energetics Buildings at the High Explosive Research and Development Facility (HERD) Final Environmental Assessment

    DTIC Science & Technology

    2003-06-01

    comprise the understory (U.S. Air Force, 1995). Some of the dominant plant families include the sunflower (Asteraceae), milkweed (Asclepiadaceae), sedge ... Cyperaceae ), heath (Ericaceae), pea (Fabaceae), grass (Poaceae or Gramineae), buckwheat (Polygonaceae), and the yellow-eyed grass (Xyridaceae

  16. Cultural Resource Investigations in the L’Anguille River Basin, Lee, St. Francis, Cross and Poinsett Counties, Arkansas.

    DTIC Science & Technology

    1989-01-01

    7). In this early-Holocene zone, other nonwoody plants with substantial percentages of microfossils included sedges (family Cyperaceae , from 5 up to...Quercus-Gramineae Pollen Assemblage Zone (age 11,250 to 9500 yr B.P.; core depth 330 to 297 cm) 22 xliv. Quercus- Cyperaceae Pollen Assemblage Zone (age...schreberi). Fossil seeds and fruits were identified as marsh herbs such as grasses (family Gramineae), sedges (Cyperus strigosus type), goosefoot

  17. Cultural Resources Survey and Archeological Inventory of the Proposed Carrollton Revetment Project, Orleans Parish, Louisiana, Phase 1. Volume 1 of 2

    DTIC Science & Technology

    2004-11-01

    covered with Berchmis scandens Rattan vine Gramineae Various gasses large tracts of sugarcane, cotton, rice, tobacco, Cyperaceae Sedges indigo, and...permeability, ous grasses (Gramineae) and sedges (Cyper- and the shrinking and swelling of the subsoil. In aceae) (Craig et al. 1987; Penfound and Hatha...sheds, and other ma- location of the cavalry camp can be drawn. terial either [were] removed or destroyed by Although the exact locations of the Sedg

  18. A Comparison of Spatial and Spectral Image Resolution for Mapping Invasive Plants in Coastal California

    NASA Astrophysics Data System (ADS)

    Underwood, Emma C.; Ustin, Susan L.; Ramirez, Carlos M.

    2007-01-01

    We explored the potential of detecting three target invasive species: iceplant ( Carpobrotus edulis), jubata grass ( Cortaderia jubata), and blue gum ( Eucalyptus globulus) at Vandenberg Air Force Base, California. We compared the accuracy of mapping six communities (intact coastal scrub, iceplant invaded coastal scrub, iceplant invaded chaparral, jubata grass invaded chaparral, blue gum invaded chaparral, and intact chaparral) using four images with different combinations of spatial and spectral resolution: hyperspectral AVIRIS imagery (174 wavebands, 4 m spatial resolution), spatially degraded AVIRIS (174 bands, 30 m), spectrally degraded AVIRIS (6 bands, 4 m), and both spatially and spectrally degraded AVIRIS (6 bands, 30 m, i.e., simulated Landsat ETM data). Overall success rates for classifying the six classes was 75% (kappa 0.7) using full resolution AVIRIS, 58% (kappa 0.5) for the spatially degraded AVIRIS, 42% (kappa 0.3) for the spectrally degraded AVIRIS, and 37% (kappa 0.3) for the spatially and spectrally degraded AVIRIS. A true Landsat ETM image was also classified to illustrate that the results from the simulated ETM data were representative, which provided an accuracy of 50% (kappa 0.4). Mapping accuracies using different resolution images are evaluated in the context of community heterogeneity (species richness, diversity, and percent species cover). Findings illustrate that higher mapping accuracies are achieved with images possessing high spectral resolution, thus capturing information across the visible and reflected infrared solar spectrum. Understanding the tradeoffs in spectral and spatial resolution can assist land managers in deciding the most appropriate imagery with respect to target invasives and community characteristics.

  19. A comparison of spatial and spectral image resolution for mapping invasive plants in coastal california.

    PubMed

    Underwood, Emma C; Ustin, Susan L; Ramirez, Carlos M

    2007-01-01

    We explored the potential of detecting three target invasive species: iceplant (Carpobrotus edulis), jubata grass (Cortaderia jubata), and blue gum (Eucalyptus globulus) at Vandenberg Air Force Base, California. We compared the accuracy of mapping six communities (intact coastal scrub, iceplant invaded coastal scrub, iceplant invaded chaparral, jubata grass invaded chaparral, blue gum invaded chaparral, and intact chaparral) using four images with different combinations of spatial and spectral resolution: hyperspectral AVIRIS imagery (174 wavebands, 4 m spatial resolution), spatially degraded AVIRIS (174 bands, 30 m), spectrally degraded AVIRIS (6 bands, 4 m), and both spatially and spectrally degraded AVIRIS (6 bands, 30 m, i.e., simulated Landsat ETM data). Overall success rates for classifying the six classes was 75% (kappa 0.7) using full resolution AVIRIS, 58% (kappa 0.5) for the spatially degraded AVIRIS, 42% (kappa 0.3) for the spectrally degraded AVIRIS, and 37% (kappa 0.3) for the spatially and spectrally degraded AVIRIS. A true Landsat ETM image was also classified to illustrate that the results from the simulated ETM data were representative, which provided an accuracy of 50% (kappa 0.4). Mapping accuracies using different resolution images are evaluated in the context of community heterogeneity (species richness, diversity, and percent species cover). Findings illustrate that higher mapping accuracies are achieved with images possessing high spectral resolution, thus capturing information across the visible and reflected infrared solar spectrum. Understanding the tradeoffs in spectral and spatial resolution can assist land managers in deciding the most appropriate imagery with respect to target invasives and community characteristics.

  20. [Structural characteristics of Artemisia frigid community at different succession stages in Horqin Sandy Land].

    PubMed

    Li, Yan-qing; Sun, Ying-jie; Zhang, Tong-hui; Zhao, Ai-fen; Lian, Jie

    2011-07-01

    Taking space as a substitute for time, this paper studied the species composition and species diversity of Artemisia frigid community at three succession stages in Horqin Sandy Land. The three succession stages were Periploca sepium-A. frigida community, Periploca sepium-A. frigida+A. halodendron community, and A. frigida-Cleistogenes squarrosa community, all dominated by the plants of Compositae, Chenopodiaceae and Gramineae. The species number and family number in the communities and the species number of Gramineae decreased with succession, while the percentages of Compositae and Gramineae species increased. The species diversity of the communities was in the order of P. sepium-A. frigida+A. halodendron > P. sepium-A. frigida >A. frigida-C. squarrosa. No obvious difference was observed in the species composition among the three communities. In the three communities, A. frigida had the highest coverage, and the coverage increased with succession.

  1. Discovery, identification and comparative analysis of non-specific lipid transfer protein (nsLtp) family in Solanaceae.

    PubMed

    Liu, Wanfei; Huang, Dawei; Liu, Kan; Hu, Songnian; Yu, Jun; Gao, Gang; Song, Shuhui

    2010-12-01

    Plant non-specific lipid transfer proteins (nsLtps) have been reported to be involved in plant defense activity against bacterial and fungal pathogens. In this study, we identified 135 (122 putative and 13 previously identified) Solanaceae nsLtps, which are clustered into 8 different groups. By comparing with Boutrot's nsLtp classification, we classified these eight groups into five types (I, II, IV, IX and X). We compared Solanaceae nsLtps with Arabi-dopsis and Gramineae nsLtps and found that (1) Types I, II and IV are shared by Solanaceae, Gramineae and Arabidopsis; (2) Types III, V, VI and VIII are shared by Gramineae and Arabidopsis but not detected in Solanaceae so far; (3) Type VII is only found in Gramineae whereas type IX is present only in Arabidopsis and Solanaceae; (4) Type X is a new type that accounts for 52.59% Solanaceae nsLtps in our data, and has not been reported in any other plant so far. We further built and compared the three-dimensional structures of the eight groups, and found that the major functional diversification within the nsLtp family could be predated to the monocot/dicot divergence, and many gene duplications and sequence variations had happened in the nsLtp family after the monocot/dicot divergence, especially in Solanaceae.

  2. Nature's Cholesterol-Lowering Drug: Isolation and Structure Elucidation of Lovastatin from Red Yeast Rice-Containing Dietary Supplements

    ERIC Educational Resources Information Center

    Nazri, Maisarah Mohd; Samat, Farah D.; Kavanagh, Pierce V.; Walsh, John J.

    2012-01-01

    Red yeast rice, produced by fermenting the fungus, "Monascus purpureus", on rice ("Oryza sativa" L. gramineae), is commonly used as a dietary supplement. It contains lovastatin, a member of the statin family of compounds, and is licensed for use as a cholesterol-lowering agent. This experiment involves the isolation and structure elucidation of…

  3. H genome specific repetitive sequence, pEt2, of Elymus trachycaulus in part of Afa family of Triticeae.

    PubMed

    Nagaki, K; Tsujimoto, H; Sasakuma, T

    1998-02-01

    The H genome specific repetitive sequence of Elymus trachycaulus, pEt2, consists of three units of a 337-339 bp repeat aligned in tandem. The sequence is homologous to Afa-family sequences that are widely distributed in the genomes of Triticeae (Gramineae) species.

  4. Gramene: a bird's eye view of cereal genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice, maize, sorghum, wheat, barley and the other major crop grasses from the family Poaceae (Gramineae) are mankind's most important source of calories and contribute tens of billions of dollars annually to the world economy (FAO 1999, http://www.fao.org; USDA 1997, http://www.usda.gov). Continued...

  5. Effects of Seed Treatments on Germination

    DTIC Science & Technology

    1994-09-01

    34• Birdsfoot trefoil [ Lotus corniculatus L.1 The seeds were treated as in number 3 above "* Buffalograss [Buchloe dactyloides Nutt.) except that the...Birdsfoot trefoil [ Lotus corniculatus L ] al. 1973). Family Gramineae Subfamily Poaceae GRASSES Tribe Chlorideae Buffalograss I Buchloe dactyloides...1973). cold, some cultivars are available with improved low-temperature resistance. There are conflicting Birdsfoot trefoil ( Lotus corniculatus

  6. Building Salt Marshes Along the Coasts of the Continental United States

    DTIC Science & Technology

    1979-05-01

    shoreline which is periodically flooded by sact or brackish water. A number of species in the grass family (gramineae), sedge family ( cyperaceae ), and...47 d. North Pacific Coast ..... ................. ... 47 (1) Pickleweed ........ ................... 50 (2) Sedge ...64 (2) Plants ....... ..................... .64 d. Black Needle Rush ...... .................. ... 66 e. Sedge

  7. A COMPARISON OF LEAF APPEARANCE RATES AMONG TEOSINTE, MAIZE LANDRACES AND MODERN MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rate at which successive new leaves emerge at the stem apex in gramineae (phyllochron) is largely controlled by temperature. Utilizing genetic variation for the phyllochron may be a way to alter plants’ responses to the environment or to manipulate time to maturity. Little is known about possibl...

  8. Gene duplication, silencing and expression alteration govern the molecular evolution of PRC2 genes in plants.

    PubMed

    Furihata, Hazuka Y; Suenaga, Kazuya; Kawanabe, Takahiro; Yoshida, Takanori; Kawabe, Akira

    2016-10-13

    PRC2 genes were analyzed for their number of gene duplications, dN/dS ratios and expression patterns among Brassicaceae and Gramineae species. Although both amino acid sequences and copy number of the PRC2 genes were generally well conserved in both Brassicaceae and Gramineae species, we observed that some rapidly evolving genes experienced duplications and expression pattern changes. After multiple duplication events, all but one or two of the duplicated copies tend to be silenced. Silenced copies were reactivated in the endosperm and showed ectopic expression in developing seeds. The results indicated that rapid evolution of some PRC2 genes is initially caused by a relaxation of selective constraint following the gene duplication events. Several loci could become maternally expressed imprinted genes and acquired functional roles in the endosperm.

  9. [Pollen counts (from Ambrosia and Artemisia) in Lyon-Bron from 1982 to 1985].

    PubMed

    Dechamp, C; Hoch, D; Chouraqui, M; Bensoussan, M; Dechamp, J

    1987-06-01

    The purpose of this work is to distinguish the broad outlines of the pollen calendar in the Lyons area for the 5th year, using the same method (P. COUR) and the same location--Lyon-Bron weather station. Weekly data is given for 1982, 1983, 1984, 1985 (1986 data was not complete at the time of the conference, October 1986). This work is the fruit of numerical counts integrated into a data processing program which enables pollens tested and not tested in allergology to be identified. In Lyon, we observe 3 pollen seasons: early Spring (TREES), Spring (TREES and GRAMINEAE) and Summer-Autumn (TREES, GRAMINEAE, and COMPOSITAE). During the late the following are present: Artemisia vulgaris (last 10 days of July), RAGWEED (mid-August-1st fortnight of October), Artemisia annua (end September-early October). The particularity of our region is that not only ragweed pollen is collected but also two categories of Mugwort pollen, at different periods.

  10. Stationing a U.S. Army Reserve Black Hawk Helicopter Company at Joint Forces Training Base Los Alamitos, California

    DTIC Science & Technology

    2011-03-01

    94043 Prepared by: 4422 East Indian School Road Suite 101 Phoenix, Arizona 85018 DOCUMENT NUMBER USACE0910-03-00-0234 March 2011 Top ...billed Tern (Sterna nilotica) Song Sparrow (graminea ssp.) Black Skimmer (Rynchops niger) Song Sparrow ( maxillaries ssp.) Xantus’s Murrelet...force totaled 1,635,900 people, of which 135,900 were unemployed for a jobless rate of 8.3 percent. Educational, health and social services is the top

  11. Lectin cDNA and transgenic plants derived therefrom

    DOEpatents

    Raikhel, Natasha V.

    1994-01-04

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon.

  12. Lectin cDNA and transgenic plants derived therefrom

    DOEpatents

    Raikhel, N.V.

    1994-01-04

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon. .

  13. Aquatic Plant Control Research Program: An Ecological Study of Hydrilla in the Potomac River; Waterfowl Segment.

    DTIC Science & Technology

    1987-04-01

    Mallard (M) Hydrilla 100 Polygonum trace Mallard (F) Bryozoa 50 Gastropoda 50 Mallard (F) Hydrilla 100 Mallard (F) Hydrilla 100 Polygonum trace...r r opp., Gastropoda, Bryozoa , and Graminea. 3. The following are the findings for each bird. %’,I v Mallard Male 5 Sep 85 % Gullet Gizzard Hydrilla...Hydrilla 100% Gastropods trace Gastropod& trace Grit: 6.4 g 4.0 cc Mallard Female 5 Sep 85 Gullet Gizzard (3 cc food) empty Bryozoa 50% Gastropoda 50% Grit

  14. The Mattassee Lake Sites: Archeological Investigations Along the Lower Santee River in the Coastal Plain of South Carolina.

    DTIC Science & Technology

    1982-12-01

    340 .- q Fourteen taxa were identified: Woodland features at site 38BK246 yielded GRAMINEAE (Grass family), CYPERACEAE blackberry and dogwood. ( sedge ... sedge , pickerelweed, bayberry and Nyssa or Biplisia spp.), and grape seed (Widmer spp. (if this is tupelo, N. sylvatica). 1976a:36). The seeds were...with the swamp or swamp margin, including americana (poke), Rubus spp. (blackberry), sedge , pickerelweed, bayberry and possibly LEGUMICOSAE (Bean family

  15. SOIL FLUXES OF CO2, CO, NO AND N2O FROM AN OLD-PASTURE AND FROM NATIVE SAVANNA IN BRAZIL

    EPA Science Inventory

    We compared fluxes of CO2, CO, NO and N2O, soil microbial biomass, and N-mineralization rates in a 20-year old Brachiaria pasture and a native cerrado area (savanna in Central Brazil). In order to assess the spatial variability of CO2 fluxes, we tested the relation between elect...

  16. Effects of Different Treatments of Pasture Restoration on Soil Trace Gas Emissions in the Cerrados of Central Brazil

    EPA Science Inventory

    Planted pastures ( mainly Brachiaria spp) are the most extensive land use in the cerrado (savannas of central Brazil) with an area of approximately 50 x 10(6) ha. The objective of the study was to assess the effects of pasture restoration on the N dynamics ( net N mineralization/...

  17. Case 3058. Arctocephalus F. Cuvier, 1826 and Callorhinus Gray, 1859 (Mammalia, Pinnipedia): proposed conservation by the designation of Phoca pusilla Schreber, [1775] as the type species of Arctocephalus; and Otaria Peron, 1816 and Eumetopias Gill, 1866: proposed conservation by the designation of Phoca leonina Molina, 1782 as the type species of Otaria

    USGS Publications Warehouse

    Gardner, A.L.; Robbins, C.B.

    1999-01-01

    The purpose of this application is to conserve the accustomed understanding and usage of the fur seal name Arctocephalus F. Cuvier, 1826 by the designation of Phoca pusilia Schreber, [1775] as the type species, thus conserving also the name Callorhinus Gray, 1859. At present Phoca ursina Linnaeus, 1758 is the valid type species of both Arctocephalus and Callorhinus. The name Arctocephalus relates to a genus of some seven fur seals from the southern hemisphere, while Callorhinus is used for the single species C. ursinus (Linnaeus) from the northern hemisphere. It is also proposed that the universal understanding of the names Otaria Peron, 1816 and Eumetopias Gill, 1866 should be conserved for the southern and northern sea lions respectively by designating Phoca leonina Molina, 1782 (for which the valid specific name is P. byronia de Blainville, 1820) as the type species of Otaria. At present Phoca jubata Schreber, [1776] is the type species of Otaria and the name Otaria is a senior subjective synonym of Eumetopias. The four genera Arctocephalus, Callorhinus, Otaria and Eumetopias are all placed in the family OTARIIDAE Gray, 1825.

  18. Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species

    PubMed Central

    Katz, Aron D.; Giordano, Rosanna; Soto-Adames, Felipe

    2015-01-01

    Abstract The chaetotaxy of 15 species of eastern North American Entomobrya is redescribed in order to determine potential characters for the diagnosis of cryptic lineages and evaluate the diagnostic and phylogenetic utility of chaetotaxy. As a result, four new species (Entomobrya citrensis Katz & Soto-Adames, sp. n., Entomobrya jubata Katz & Soto-Adames, sp. n., Entomobrya neotenica Katz & Soto-Adames, sp. n. and Entomobrya unifasciata Katz & Soto-Adames, sp. n.) are described, and new diagnoses are provided for Entomobrya assuta Folsom, Entomobrya atrocincta Schött, Entomobrya decemfasciata (Packard), Entomobrya ligata Folsom, Entomobrya multifasciata (Tullberg), and Entomobrya quadrilineata (Bueker). Furthermore, previously undocumented levels of intraspecific variation in macrosetal pattern are reported, tempering the exclusive use of chaetotaxy for species delimitation. Phylogenetic relationships, estimated using both morphological and molecular data, indicate that Entomobrya is likely paraphyletic. The phylogenies also suggest that unreliable character homology, likely fostered by Entomobrya’s profusion of macrosetae, may limit the phylogenetic utility of chaetotaxy in groups characterized by an abundance of dorsal macrosetae. PMID:26487816

  19. Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species.

    PubMed

    Katz, Aron D; Giordano, Rosanna; Soto-Adames, Felipe

    2015-01-01

    The chaetotaxy of 15 species of eastern North American Entomobrya is redescribed in order to determine potential characters for the diagnosis of cryptic lineages and evaluate the diagnostic and phylogenetic utility of chaetotaxy. As a result, four new species (Entomobrya citrensis Katz & Soto-Adames, sp. n., Entomobrya jubata Katz & Soto-Adames, sp. n., Entomobrya neotenica Katz & Soto-Adames, sp. n. and Entomobrya unifasciata Katz & Soto-Adames, sp. n.) are described, and new diagnoses are provided for Entomobrya assuta Folsom, Entomobrya atrocincta Schött, Entomobrya decemfasciata (Packard), Entomobrya ligata Folsom, Entomobrya multifasciata (Tullberg), and Entomobrya quadrilineata (Bueker). Furthermore, previously undocumented levels of intraspecific variation in macrosetal pattern are reported, tempering the exclusive use of chaetotaxy for species delimitation. Phylogenetic relationships, estimated using both morphological and molecular data, indicate that Entomobrya is likely paraphyletic. The phylogenies also suggest that unreliable character homology, likely fostered by Entomobrya's profusion of macrosetae, may limit the phylogenetic utility of chaetotaxy in groups characterized by an abundance of dorsal macrosetae.

  20. Myosin heavy chain composition of tiger (Panthera tigris) and cheetah (Acinonyx jubatus) hindlimb muscles.

    PubMed

    Hyatt, Jon-Philippe K; Roy, Roland R; Rugg, Stuart; Talmadge, Robert J

    2010-01-01

    Felids have a wide range of locomotor activity patterns and maximal running speeds, including the very fast cheetah (Acinonyx jubatas), the roaming tiger (Panthera tigris), and the relatively sedentary domestic cat (Felis catus). As previous studies have suggested a relationship between the amount and type of activity and the myosin heavy chain (MHC) isoform composition of a muscle, we assessed the MHC isoform composition of selected hindlimb muscles from these three felid species with differing activity regimens. Using gel electrophoresis, western blotting, histochemistry, and immunohistochemistry with MHC isoform-specific antibodies, we compared the MHC composition in the tibialis anterior, medial gastrocnemius (MG), plantaris (Plt), and soleus muscles of the tiger, cheetah, and domestic cat. The soleus muscle was absent in the cheetah. At least one slow (type I) and three fast (types IIa, IIx, and IIb) MHC isoforms were present in the muscles of each felid. The tiger had a high combined percentage of the characteristically slower isoforms (MHCs I and IIa) in the MG (62%) and the Plt (86%), whereas these percentages were relatively low in the MG (44%) and Plt (55%) of the cheetah. In general, the MHC isoform characteristics of the hindlimb muscles matched the daily activity patterns of these felids: the tiger has daily demands for covering long distances, whereas the cheetah has requirements for speed and power.

  1. A taxonomic guide to the fanworms (Sabellidae, Annelida) of Lizard Island, Great Barrier Reef, Australia, including new species and new records.

    PubMed

    Capa, María; Murray, Anna

    2015-09-18

    This comprehensive taxonomic work is the result of the study of fan worms (Sabellidae, Annelida) collected over the last 40 years from around the Lizard Island Archipelago, Great Barrier Reef, Australia. Some species described herein are commonly found in Lizard Island waters but had not previously been formally reported in the literature. Most species appear to be not particularly abundant, and few specimens have been collected despite the sampling effort in the area over this time period. After this study, the overall sabellid diversity of the archipelago has been greatly increased (by more than 650%). Before this revision, only four sabellid species had been recorded for Lizard Island, and in this paper we report 31 species, 13 of which belong to nominal species, six are formally described as new species (Euchone danieloi n. sp., Euchone glennoi n. sp., Jasmineira gustavoi n. sp., Megalomma jubata n. sp., Myxicola nana n. sp., and Paradialychone ambigua n. sp.), and the identity of 12 species is still unknown (those referred as cf. or sp.). Two species are newly recorded in Australia and two in Queensland. The invasive species Branchiomma bairdi is reported for the first time at Lizard Island. The genus Paradialychone is reported for Australia for the first time. Standardised descriptions, general photographs of live and/or preserved specimens and distribution data are provided for all species. New species descriptions are accompanied by detailed illustrations and exhaustive morphological information. A dichotomous key for sabellid identification is also included.

  2. [Distribution characteristics of soil nematodes in reclaimed land of copper-mine-tailings in different plant associations].

    PubMed

    Zhu, Yong-heng; Li, Ke-zhong; Zhang, Heng; Han, Fei; Zhou, Ju-hua; Gao, Ting-ting

    2015-02-01

    A survey was carried out to investigate soil nematode communities in the plant associations of gramineae (Arthraxon lanceolatus, AL; Imperata cylindrica, IC) and leguminosae (Glycine soja, GS) in reclaimed land of copper-mine-tailings and in the plant associations of gramineae (Digitaria chrysoblephara, DC-CK) of peripheral control in Fenghuang Mountain, Tongling City. A total of 1277 nematodes were extracted and sorted into 51 genera. The average individual density of the nematodes was 590 individuals · 100 g(-1) dry soil. In order to analyze the distribution character- istics of soil nematode communities in reclaimed land of copper-mine-tailings, Shannon community diversity index and soil food web structure indices were applied in the research. The results showed that the total number of nematode genus and the Shannon community diversity index of soil nematode in the three plant associations of AL, IC and GS were less than that in the plant associations of DC-CK. Compared with the ecological indices of soil nematode communities among the different plant associations in reclaimed land of copper-mine-tailings and peripheral natural habitat, we found that the structure of soil food web in the plant associations of GS was more mature, with bacterial decomposition being dominant in the soil organic matter decomposition, and that the soil ecosystem in the plant associations of GS was not stable with low interference. This indicated that the soil food web in the plant associations of leguminosae had a greater development potential to improve the ecological stability of the reclaimed land of copper-mine-tailings. On the other hand, the structure of soil food web in the plant associations of AL and IC were relatively stable in a structured state with fungal decomposition being dominant in the decomposition of soil organic matter. This indicated that the soil food web in the plant associations of gramineae was at a poor development level.

  3. Dynamics of the chemical composition and productivity of composts for the cultivation of Agaricus bisporus strains.

    PubMed

    de Andrade, Meire Cristina Nogueira; de Jesus, João Paulo Furlan; Vieira, Fabrício Rocha; Viana, Sthefany Rodrigues Fernandes; Spoto, Marta Helena Fillet; de Almeida Minhoni, Marli Teixeira

    2013-12-01

    Two compost formulations based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) were tested for the cultivation of three Agaricus bisporus strains (ABI-07/06, ABI-05/03, and PB-1). The experimental design was a 2 × 3 factorial scheme (composts × strains) with 6 treatments and 8 repetitions (boxes containing 12 kg of compost). The chemical characterization of the compost (humidity, organic matter, carbon, nitrogen, pH, raw protein, ethereal extract, fibers, ash, cellulose, hemicellulose, and lignin) before and after the cultivation of A. bisporus and the production (basidiomata mass, productivity, and biological efficiency) were evaluated. Data were submitted to variance analysis, and averages were compared by means of the Tukey's test. According to the results obtained, the chemical and production characteristics showed that the best performances for the cultivation of A. bisporus were presented by the compost based on oat and the strain ABI-07/06.

  4. Dynamics of the chemical composition and productivity of composts for the cultivation of Agaricus bisporus strains

    PubMed Central

    de Andrade, Meire Cristina Nogueira; de Jesus, João Paulo Furlan; Vieira, Fabrício Rocha; Viana, Sthefany Rodrigues Fernandes; Spoto, Marta Helena Fillet; de Almeida Minhoni, Marli Teixeira

    2013-01-01

    Two compost formulations based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) were tested for the cultivation of three Agaricus bisporus strains (ABI-07/06, ABI-05/03, and PB-1). The experimental design was a 2 × 3 factorial scheme (composts × strains) with 6 treatments and 8 repetitions (boxes containing 12 kg of compost). The chemical characterization of the compost (humidity, organic matter, carbon, nitrogen, pH, raw protein, ethereal extract, fibers, ash, cellulose, hemicellulose, and lignin) before and after the cultivation of A. bisporus and the production (basidiomata mass, productivity, and biological efficiency) were evaluated. Data were submitted to variance analysis, and averages were compared by means of the Tukey’s test. According to the results obtained, the chemical and production characteristics showed that the best performances for the cultivation of A. bisporus were presented by the compost based on oat and the strain ABI-07/06. PMID:24688503

  5. Effect of plant trichomes on the vertical migration of Haemonchus contortus infective larvae on five tropical forages.

    PubMed

    Oliveira, Aruaque L F; Costa, Ciniro; Rodella, Roberto A; Silva, Bruna F; Amarante, Alessandro F T

    2009-06-01

    The influence of trichomes on vertical migration and survival of Haemonchus contortus infective larvae (L3) on different forages was investigated. Four different forages showing different distributions of trichomes (Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Xaraes, Andropogon gayanus, and Stylosanthes spp.), and one forage species without trichomes (Panicum maximum cv. Tanzania), were used. Forages cut at the post-grazing height were contaminated with faeces containing L3. Samples of different grass strata (0-10, 10-20, >20 cm) and faeces were collected for L3 quantification once per week over four weeks. In all forages studied, the highest L3 recovery occurred seven days after contamination, with the lowest recovery on A. gayanus. In general, larvae were found on all forages' strata. However, most of the larvae were at the lower stratum. There was no influence of trichomes on migration and survival of H. contortus L3 on the forages.

  6. Genome wide transcriptional profiling of Herbaspirillum seropedicae SmR1 grown in the presence of naringenin

    PubMed Central

    Tadra-Sfeir, Michelle Z.; Faoro, Helisson; Camilios-Neto, Doumit; Brusamarello-Santos, Liziane; Balsanelli, Eduardo; Weiss, Vinicius; Baura, Valter A.; Wassem, Roseli; Cruz, Leonardo M.; De Oliveira Pedrosa, Fábio; Souza, Emanuel M.; Monteiro, Rose A.

    2015-01-01

    Herbaspirillum seropedicae is a diazotrophic bacterium which associates endophytically with economically important gramineae. Flavonoids such as naringenin have been shown to have an effect on the interaction between H. seropedicae and its host plants. We used a high-throughput sequencing based method (RNA-Seq) to access the influence of naringenin on the whole transcriptome profile of H. seropedicae. Three hundred and four genes were downregulated and seventy seven were upregulated by naringenin. Data analysis revealed that genes related to bacterial flagella biosynthesis, chemotaxis and biosynthesis of peptidoglycan were repressed by naringenin. Moreover, genes involved in aromatic metabolism and multidrug transport efllux were actived. PMID:26052319

  7. Molecular analysis of small grain cereal genomes: Current status and prospects

    SciTech Connect

    Moore, G.; Gale, M.D. ); Flavell, R.B. ); Kurata, N. )

    1993-05-01

    Recent developments in cereal genome analysis include generation of RFLP maps, flow sorting of chromosomes, identification of landmareks for genes and a more advanced model for cereal genome organization. These developments ar reviewed together with new prospects for the isolation of defined genes from large cereal genomes and for the production of a composite map of the ancestral grass genome to aid in the genetic analysis of all the Gramineae. The advances that can now come from comparative genome mapping are likely to promote further the new era of plant genetics. 65 refs., 2 figs.

  8. How will Mahanarva spectabilis (Hemiptera: Cercopidae) Respond to Global Warming?

    PubMed Central

    Auad, A. M.; Resende, T. T.; Hott, M. C.; Borges, C.A.V.

    2016-01-01

    The aim of this study was to determine the favorable constant temperature range for Mahanarva spectabilis (Distant) (Hemiptera: Cercopidae) development as well as to generate geographic distribution maps of this insect pest for future climate scenarios. M. spectabilis eggs were reared on two host plants (Brachiaria ruziziensis (Germain and Edvard) and Pennisetum purpureum (Schumach)), with individual plants kept at temperatures of 16, 20, 24, 28, and 32°C. Nymphal stage duration, nymphal survival, adult longevity, and egg production were recorded for each temperature*host plant combination. Using the favorable temperature ranges for M. spectabilis development, it was possible to generate geographic distribution. Nymphal survival was highest at 24.4°C, with estimates of 44 and 8% on Pennisetum and Brachiaria, respectively. Nymphal stage duration was greater on Brachiaria than on Pennisetum at 20 and 24°C but equal at 28°C. Egg production was higher on Pennisetum at 24 and 28°C than at 20°C, and adult longevity on Pennisetum was higher at 28°C than at 20°C, whereas adult longevity at 24°C did not differ from that at 20 and 28°C. With these results, it was possible to predict a reduction in M. spectabilis densities in most regions of Brazil in future climate scenarios. PMID:27012869

  9. How will Mahanarva spectabilis (Hemiptera: Cercopidae) Respond to Global Warming?

    PubMed

    Fonseca, M G; Auad, A M; Resende, T T; Hott, M C; Borges, C A V

    2016-01-01

    The aim of this study was to determine the favorable constant temperature range for Mahanarva spectabilis(Distant) (Hemiptera: Cercopidae) development as well as to generate geographic distribution maps of this insect pest for future climate scenarios. M. spectabilis eggs were reared on two host plants (Brachiaria ruziziensis(Germain and Edvard) and Pennisetum purpureum(Schumach)), with individual plants kept at temperatures of 16, 20, 24, 28, and 32 °C. Nymphal stage duration, nymphal survival, adult longevity, and egg production were recorded for each temperature*host plant combination. Using the favorable temperature ranges for M. spectabilis development, it was possible to generate geographic distribution. Nymphal survival was highest at 24.4 °C, with estimates of 44 and 8% on Pennisetum and Brachiaria, respectively. Nymphal stage duration was greater on Brachiaria than on Pennisetum at 20 and 24 °C but equal at 28 °C. Egg production was higher on Pennisetum at 24 and 28 °C than at 20 °C, and adult longevity on Pennisetum was higher at 28 °C than at 20 °C, whereas adult longevity at 24 °C did not differ from that at 20 and 28 °C. With these results, it was possible to predict a reduction in M. spectabilis densities in most regions of Brazil in future climate scenarios.

  10. Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

    NASA Astrophysics Data System (ADS)

    Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

    2015-11-01

    In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group (PFG) quantity factors during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunchgrasses to rhizome plexus and dense-plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

  11. Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

    NASA Astrophysics Data System (ADS)

    Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

    2015-08-01

    In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group quantity factors (PFGs) during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunch grasses to rhizome plexus and dense plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by Sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

  12. Gene distribution and isochore organization in the nuclear genome of plants.

    PubMed

    Montero, L M; Salinas, J; Matassi, G; Bernardi, G

    1990-04-11

    The genomic distribution of 23 nuclear genes from three dicotyledons (pea, sunflower, tobacco) and five monocotyledons of the Gramineae family (barley, maize, rice, oat, wheat) was studied by localizing these genes in DNA fractions obtained by preparative centrifugation in Cs2SO4/BAMD density gradients. Each one of these genes (and of many other related genes and pseudogenes) was found to be located in DNA fragments (50-100 Kb in size) that were less than 1-2% GC apart from each other. This definitively demonstrates the existence of isochores in plant genomes, namely of compositionally homogeneous DNA regions at least 100-200 Kb in size. Moreover, the GC levels of the 23 coding sequences studied, of their first, second and third codon positions, and of the corresponding introns were found to be linearly correlated with the GC levels of the isochores harboring those genes. Compositional correlations displayed increasing slopes when going from second to first to third codon position with obvious effects on codon usage. Coding sequences for seed storage proteins and phytochrome of Gramineae deviate from the compositional correlations just described. Finally, CpG doublets of coding sequences were characterized by a shortage that decreased and vanished with increasing GC levels of the sequences. A number of these findings bear a striking similarity with results previously obtained for vertebrate genes.

  13. Late glacial aridity in southern Rocky Mountains

    SciTech Connect

    Davis, O.K.; Pitblado, B.L.

    1995-09-01

    While the slopes of the present-day Colorado Rocky Mountains are characterized by large stands of subalpine and montane conifers, the Rockies of the late glacial looked dramatically different. Specifically, pollen records suggest that during the late glacial, Artemisia and Gramineae predominated throughout the mountains of Colorado. At some point between 11,000 and 10,000 B.P., however, both Artemisia and grasses underwent a dramatic decline, which can be identified in virtually every pollen diagram produced for Colorado mountain sites, including Como Lake (Sangre de Cristo Mountains), Copley Lake and Splains; Gulch (near Crested Butte), Molas Lake (San Juan Mountains), and Redrock Lake (Boulder County). Moreover, the same pattern seems to hold for pollen spectra derived for areas adjacent to Colorado, including at sites in the Chuska Mountains of New Mexico and in eastern Wyoming. The implications of this consistent finding are compelling. The closest modem analogues to the Artemisia- and Gramineae-dominated late-glacial Colorado Rockies are found in the relatively arid northern Great Basin, which suggests that annual precipitation was much lower in the late-glacial southern Rocky Mountains than it was throughout the Holocene.

  14. Paleoenvironment of the Lowest Hominid-bearing Bed in the Sangiran Area, Indonesia

    NASA Astrophysics Data System (ADS)

    Kitaba, I.; Hyodo, M.; Matsu'ura, S.; Kondo, M.; Takeshita, Y.; Aziz, F.; Kumai, H.

    2012-12-01

    The first hominid migration out of Africa and dispersion to the eastern Asia are one of the main anthropological issues. However, we do not have consensus on their ages and pathway. The Sangiran area, Indonesia, has yielded more than 80 Homo erectus fossils. The mandibular bone, Pithecanthropus B (Sangiran 1b), has been found around the T11 volcanic ash layer in the upper part of the Sangiran Formation (the Lower Pleistocene). This specimen is one of the oldest Sangiran hominid fossils. Magnetostratigraphy shows that the T11 lies around the lower boundary of the Jaramillo subchronozone (1.07 Ma). We carried out pollen analysis of the sequence across T11 to reveal paleoenvironment when the possible first hominid arrival occurred in the Sangiran area, and discuss the causes of the emigration and settlement. In the layer from 1.0 m below to 0.5 m above T11, herbaceous taxa including Gramineae (> 50%) is dominant. They are accompanied by the aquatic taxa Typha and freshwater algae Pediastrum. The abundance of Gramineae shows dry environment. This sequence is also characterized by occurrences of Casuarinaga and Lagerstroemia, Salix, Corylus and Myrica, all living in dry lowlands. These features show that there was an open forest near freshwater. Around 0.5 m above T11, a big change in environment occurred. In the sequence above it, Gramineae (30-50%) decreased and Casuarinaga almost disappeared. Additionally, an increase in spores (10-40%) preferring a wet land shows an occurrence of wetting. At the same time, Manilkara (20-50%) increased sharply and became a main component of vegetation. The percentages of Psidium and Musa rose slightly. These taxa consist of many edible fruits. The lowland taxa like Lagerstroemia or Salix disappeared, which might show an occurrence of cooling. These environmental changes are consistent with the previous study based on diatom analysis. The result shows that around T11 there was a transgression, which may be correlated with marine

  15. Nasal filters in prevention of seasonal rhinitis induced by allergenic pollen grains. Open clinical study.

    PubMed

    D'Amato, G; Liccardi, G; Salzillo, A; Russo, M; Narciso, P; Allegra, L

    2012-04-01

    Nasal filters (Sanispira) might represent a novel approach in preventing exacerbations of symptoms of seasonal allergic rhinitis by reducing pollen access to nasal cavities. Female and male voluntary patients between the ages of 18 and 64 years living in Naples area and affected by allergic rhinitis were recruited in an open clinical study. All were allergic to Parietaria pollen as assessed by skin-prick and/or RAST test with or without associated sensitization to other pollens such as Gramineae and Olea europaea. A pollen count was also carried out from 10th April until 30th of June 2011. The results of our study show positive statistical differences between the scores of common nasal symptoms and the reduced use of antihistaminic drugs in patients using nasal filters in comparison to non users. Nasal filters constitute a useful mean to reduce symptoms of seasonal allergic rhinitis in patients suffering from pollen allergy.

  16. Floristic diversity and vegetation analysis of Wadi Arar: A typical desert Wadi of the Northern Border region of Saudi Arabia.

    PubMed

    Osman, Ahmed K; Al-Ghamdi, Faraj; Bawadekji, Abdulhakim

    2014-12-01

    Wadi Arar in the Northern border region of Saudi Arabia is one of the most important Wadis of the Kingdom. The present study provides an analysis of vegetation types, life forms, as well as floristic categories and species distribution. A total of 196 species representing 31 families of vascular plants were recorded. Compositae, Gramineae and Leguminosae were the most common families. Therophytes and chamaephytes are the most frequent life forms, indicating typical desert spectrum vegetation. The distribution of these species in the different sectors of the Wadi as well as the phytochoria for the recorded species is provided. Ninety-one species (46.5%) are typical bi-regional. Furthermore, about 105 species (53.5%) are mono- or pluriregional taxa. The highest number of species (136 or 69.5%) was recorded for annual plants, while the lowest number of species (60% or 30.5%) was recorded for perennial, short perennial or annual to biennial species.

  17. Floristic diversity and vegetation analysis of Wadi Arar: A typical desert Wadi of the Northern Border region of Saudi Arabia

    PubMed Central

    Osman, Ahmed K.; Al-Ghamdi, Faraj; Bawadekji, Abdulhakim

    2014-01-01

    Wadi Arar in the Northern border region of Saudi Arabia is one of the most important Wadis of the Kingdom. The present study provides an analysis of vegetation types, life forms, as well as floristic categories and species distribution. A total of 196 species representing 31 families of vascular plants were recorded. Compositae, Gramineae and Leguminosae were the most common families. Therophytes and chamaephytes are the most frequent life forms, indicating typical desert spectrum vegetation. The distribution of these species in the different sectors of the Wadi as well as the phytochoria for the recorded species is provided. Ninety-one species (46.5%) are typical bi-regional. Furthermore, about 105 species (53.5%) are mono- or pluriregional taxa. The highest number of species (136 or 69.5%) was recorded for annual plants, while the lowest number of species (60% or 30.5%) was recorded for perennial, short perennial or annual to biennial species. PMID:25473364

  18. Seasonal prevalence of air-borne pollen and spores in Kuala Lumpur, Malaysia.

    PubMed

    Ho, T M; Tan, B H; Ismail, S; Bujang, M K

    1995-06-01

    Aerosampling using Rotorod samplers was conducted in the Institute for Medical Research, Kuala Lumpur, Malaysia, from December 1991 to November 1993. Samples were collected twice a week between 10.00 hours to 12.00 hours. Rods were stained and examined microscopically. A total of 8 and 20 types of pollens and mold spores were collected, respectively. More mold spores were collected than pollens. Grass pollen constituted more than 40 percent of total pollen counts. Gramineae pollen counts peaked in March and September. The most abundant mold spore was Cladosporium followed by Rust, Nigrospora, Curvularia and Smut. Cladosporium counts peaked in February and August. Rust counts peaked in June and December whereas counts for Nigrospora peaked in February and October. Highest counts of Smut were recorded in March and October. Curvularia counts peaked in January, June and September.

  19. Analysis of glabrous canary seeds by ELISA, mass spectrometry, and Western blotting for the absence of cross-reactivity with major plant food allergens.

    PubMed

    Boye, Joyce Irene; Achouri, Allaoua; Raymond, Nancy; Cleroux, Chantal; Weber, Dorcas; Koerner, Terence B; Hucl, Pierre; Patterson, Carol Ann

    2013-06-26

    Glabrous (hairless) canary seed belongs to the Poaceae (Gramineae) family and could serve as an alternative source of gluten-free cereal grain. In this study, allergenic cross-reactivities between hairless, dehulled canary seeds (Phalaris canariensis) and major allergenic proteins from gluten, soy, peanuts, tree nuts, sesame, and mustard were studied using commercial enzyme-linked immune sorbent assay (ELISA) kits specific for these target allergens. Mass spectrometry (MS) and immunoblotting were further used to assess for the presence of gluten-specific protein fragments. MS results revealed the likely presence of proteins homologous with rice, oat, corn, carrot, tomato, radish, beet, and chickpea. However, no presence of celiac-related gluten fragments from wheat, rye, barley, or their derivatives was found. Immunoblotting studies yielded negative results, further confirming the absence of gluten in the canary seed samples tested. No cross-reactivities were detected between canary seeds and almond, hazelnut, mustard, peanut, sesame, soy, walnut, and gluten using ELISA.

  20. Comparative Analysis of Benzoxazinoid Biosynthesis in Monocots and Dicots: Independent Recruitment of Stabilization and Activation Functions[W][OA

    PubMed Central

    Dick, Regina; Rattei, Thomas; Haslbeck, Martin; Schwab, Wilfried; Gierl, Alfons; Frey, Monika

    2012-01-01

    Benzoxazinoids represent preformed protective and allelophatic compounds that are found in a multitude of species of the family Poaceae (Gramineae) and occur sporadically in single species of phylogenetically unrelated dicots. Stabilization by glucosylation and activation by hydrolysis is essential for the function of these plant defense compounds. We isolated and functionally characterized from the dicot larkspur (Consolida orientalis) the benzoxazinoid-specific UDP-glucosyltransferase and β-glucosidase that catalyze the enzymatic functions required to avoid autotoxicity and allow activation upon challenge by herbivore and pathogen attack. A phylogenetic comparison of these enzymes with their counterparts in the grasses indicates convergent evolution by repeated recruitment from homologous but not orthologous genes. The data reveal a great evolutionary flexibility in recruitment of these essential functions of secondary plant metabolism. PMID:22415274

  1. New alpha-L-arabinofuranosidase produced by Streptomyces lividans: cloning and DNA sequence of the abfB gene and characterization of the enzyme.

    PubMed Central

    Vincent, P; Shareck, F; Dupont, C; Morosoli, R; Kluepfel, D

    1997-01-01

    A fully secreted alpha-l-arabinofuranosidase was cloned from the homologous expression system of Streptomyces lividans. The gene, located upstream adjacent to the previously described xylanase A gene, was sequenced. It is divergently transcribed from the xlnA gene and the two genes are separated by an intercistronic region of 391nt which contains a palindromic AT-rich sequence. The deduced amino acid sequence of the protein shows that the enzyme contains a distinct catalytic domain which is linked to a specific xylan-binding domain by a linker region. The purified enzyme has a specific arabinofuranose-debranching activity on xylan from Gramineae, acts synergistically with the S. lividans xylanases and binds specifically to xylan. From small arabinoxylo-oligosides, it liberates arabinose and, after prolonged incubation, the purified enzyme exhibits some xylanolytic activity as well. PMID:9148759

  2. Cymbopogon species; ethnopharmacology, phytochemistry and the pharmacological importance.

    PubMed

    Avoseh, Opeyemi; Oyedeji, Opeoluwa; Rungqu, Pamela; Nkeh-Chungag, Benedicta; Oyedeji, Adebola

    2015-04-23

    Cymbopogon genus is a member of the family of Gramineae which are herbs known worldwide for their high essential oil content. They are widely distributed across all continents where they are used for various purposes. The commercial and medicinal uses of the various species of Cymbopogon are well documented. Ethnopharmacology evidence shows that they possess a wide array of properties that justifies their use for pest control, in cosmetics and as anti-inflammation agents. These plants may also hold promise as potent anti-tumor and chemopreventive drugs. The chemo-types from this genus have been used as biomarkers for their identification and classification. Pharmacological applications of Cymbopogon citratus are well exploited, though studies show that other species may also useful pharmaceutically. Hence this literature review intends to discuss these species and explore their potential economic importance.

  3. Conversion of natural aldehydes from Eucalyptus citriodora, Cymbopogon citratus, and Lippia multiflora into oximes: GC-MS and FT-IR analysis.

    PubMed

    Ouédraogo, Igor W; Boulvin, Michael; Flammang, Robert; Gerbaux, Pascal; Bonzi-Coulibaly, Yvonne L

    2009-08-31

    Three carbonyl-containing extracts of essential oils from Eucalyptus citriodora (Myrtaceae), Cymbopogon citratus (Gramineae) and Lippia multiflora (Verbenaceae) were used for the preparation of oximes. The reaction mixtures were analyzed by GC-MS and different compounds were identified on the basis of their retention times and mass spectra. We observed quantitative conversion of aldehydes to their corresponding oximes with a purity of 95 to 99%. E and Z stereoisomers of the oximes were obtained and separated by GC-MS. During GC analysis, the high temperature in the injector was shown to cause partial dehydratation of oximes and the resulting nitriles were readily identified. Based on FT-IR spectroscopy, that revealed the high stability and low volatility of these compounds, the so-obtained oximes could be useful for future biological studies.

  4. Flora characteristics of Chenier Wetland in Bohai Bay and biogeographic relations with adjacent wetlands

    NASA Astrophysics Data System (ADS)

    Zhao, Yanyun; Lu, Zhaohua; Liu, Jingtao; Hu, Shugang

    2017-01-01

    A key step towards the restoration of heavily disturbed fragile coastal wetland ecosystems is determining the composition and characteristics of the plant communities involved. This study determined and characterized the community of higher plants in the Chenier wetland of Bohai Bay using a combination of field surveys, quadrat approaches, and multivariate statistical analyses. This community was then compared to other adjacent wetlands (Tianjin, Qinhuangdao, Laizhouwan, Jiaozhouwan, and Yellow River Delta wetland) located near the Huanghai and Bohai Seas using principal coordinate analysis (PCoA). Results showed a total of 56 higher plant species belonging to 52 genera from 20 families in Chenier wetland, the majority of which were dicotyledons. Single-species families were predominant, while larger families, including Gramineae, Compositae, Leguminosae, and Chenopodiaceae contained a higher number of species (each⩾6 species). Cosmopolitan species were also dominant with apparent intrazonality. Abundance (number of species) of temperate species was twice that of tropical taxa. Species number of perennial herbs, such as Gramineae and Compositae, was generally higher. Plant diversity in the Chenier wetland, based on the Shannon-Wiener index, was observed to be between the Qinhuangdao and Laizhouwan indices, while no significant difference was found in other wetlands using the Simpson index. Despite these slight differences in diversity, PCoA based on species abundance and composition of the wetland flora suggest that the Bohai Chenier community was highly similar to the coastal wetlands in Tianjin and Laizhouwan, further suggesting that these two wetlands could be important breeding grounds and resources for the restoration of the plant ecosystem in the Chenier wetland.

  5. Effect of gamma irradiation on the nutritional quality of Agaricus bisporus strains cultivated in different composts.

    PubMed

    Andrade, Meire C N; Jesus, João P F; Vieira, Fabrício R; Viana, Sthefany R F; Spoto, Marta H F; Minhoni, Marli T A

    2014-05-14

    The effect of irradiation doses (0, 125, 250 and 500 Gy) on the nutritional quality of A. bisporus mushrooms (strains ABI-07/06, ABI-05/03 and PB-1) cultivated in composts based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) was evaluated. The experimental design was 4 x 3 x 2 factorial scheme (irradiation doses x strains x composts), with 24 treatments, consisting of two repetitions each, totaling 48 experimental units (samples of mushrooms). The samples were irradiated in Cobalt-60 irradiator, model Gammacell 220 kGy, with dose rate of 0.740 kGy h-1, according to the treatments proposed. Subsequently, the control (unirradiated) and the other treatments were maintained at 4±1°C and 90% RH in a climatic chamber for carrying out the chemical analysis of the mushrooms on the 1st and 14th day of storage. It was found that all A. bisporus strains evaluated were food with excellent nutritional value, because they presented high protein and fiber contents and low ethereal extract content; the chemical characterization of the mushrooms was influenced by the compost type in which they were cultivated; gamma irradiation influenced the chemical composition of mushrooms.

  6. Availability and toxicity of cadmium to forage grasses grown in contaminated soil.

    PubMed

    Silva, Enilson B; Fonseca, Felipe G; Alleoni, Luís R F; Nascimento, Sandra S; Grazziotti, Paulo H; Nardis, Bárbara O

    2016-09-01

    It is important to know the mechanisms for forage development, especially those related to the tolerance of potentially toxic elements, when considering their use in phytoremediation in heavy metal contaminated areas. In this study, we evaluated plant growth, concentration, and the availability of cadmium (Cd) for forage grasses (Panicum maximum Jacq. cv. Aruana and cv. Tanzânia; Brachiaria decumbens cv. Basilisk; Brachiaria brizantha cv. Xaraés and cv. Marandu) cultivated in Cd contaminated soils. The experiments were performed under greenhouse conditions over a 90-day evaluation period, and the Cd rates were 2, 4, and 12 mg/kg of soil. The relative growth rate of the forage grasses decreased as Cd rates increased, and the following descending order of susceptibility was observed: Marandu > Xaraés > Aruana > Tanzânia > Basilisk, with regard to phytotoxicity in these plants. The forage Cd concentration increased in line with increases in the Cd rates. Cd contents extracted by Mehlich-1 and by diethylenetriaminepentaacetic acid presented high positive correlation with forage relative growth. The forage plants did not block Cd entry into the food chain because they were not capable of limiting Cd absorption.

  7. Pequi leaves incorporated into the soil reduce the initial growth of cultivated, invasive and native species.

    PubMed

    Allem, Laísa N; Gomes, Anabele S; Borghetti, Fabian

    2014-12-01

    Studies have identified the phytotoxicity of many native species of the Cerrado; however, most of them were conducted either in inert substrates, or using exaggerate proportions of plant material. We investigated the phytotoxicity of pequi leaves added to substrate soil in quantities compatible with the litter produced by this species. Pequi leaves were triturated and added to red latosol in concentrations of 0.75%, 1.5% and 3%; the control was constituted of leafless soil. These mixtures were added to pots and irrigated daily to keep them moist. Germinated seeds of the cultivated sorghum and sesame, of the invasive brachiaria and of the native purple ipê, were disposed in the pots to grow for five to seven days at 30°C within a photoperiod of 12 h. Seedlings of all the species presented a reduction in their initial growth in a dose-dependent way. In general, the root growth was more affected by the treatments than the shoot growth; moreover, signs of necrosis were observed in the roots of the sorghum, sesame and brachiaria. The phytotoxic effects generated by relatively small quantities of leaves, in a reasonable range of species within a soil substrate, suggest potential allelopathy of pequi leaves under natural conditions.

  8. Phytotoxicity of cardoon (Cynara cardunculus) allelochemicals on standard target species and weeds.

    PubMed

    Rial, Carlos; Novaes, Paula; Varela, Rosa M; Molinillo, José M G; Macias, Francisco A

    2014-07-16

    Cardoon (Cynara cardunculus L.) is a native plant to the Iberian Peninsula and the European Atlantic coast and invasive in American environments. Different solvents were used to perform cardoon extracts that were tested in phytotoxic bioassays. The ethyl acetate extract had the highest inhibitory activity so this was tested on the germination and growth of standard target species (lettuce, watercress, tomato, and onion) and weeds (barnyardgrass and brachiaria). The ethyl acetate extract was very active on root growth in both standard target species and weeds and it was therefore fractionated by chromatography. The spectroscopic data showed that the major compounds were sesquiterpene lactones. Aguerin B, grosheimin, and cynaropicrin were very active on etiolated wheat coleoptile, standard target species, and weed growth. The presence of these compounds explains the bioactivity of the ethyl acetate extract. The strong phytotoxicity of these compounds on important weeds shows the potential of these compounds as natural herbicide models.

  9. Spatial Simulation of the Dynamics of Establishment of Secondary Forest in Abandoned Pasture in the Central Amazon

    NASA Astrophysics Data System (ADS)

    Rebel, K. T.; Riha, S. J.; Rondon, M. A.; Feldpausch, T. R.; Fernandes, E. C.

    2001-05-01

    In the Amazon, approximately 35 million hectares of primary forest that was converted to pasture is now being abandoned. This represents about 70% of all pastureland that was previously established. The dynamics of reconversion of this land to secondary forest is of interest because the length of time required for pasture to convert to secondary forest will impact net primary productivity and the amount of carbon being stored on abandoned pastures. In addition, the length of time required for pasture to convert to secondary forest may depend on the size of the pasture, whether it is surrounded by primary or secondary forest, and on pasture productivity at the time of abandonment. Pasture productivity at the time of abandonment will depend primarily on the age structure of the pasture grasses and on weediness, which are influenced by grazing and fire history. Also, an understanding of the dynamics of conversion of pastureland to forest can serve as the basis for management strategies to inhibit pasture conversion. A spatial, dynamic model of the conversion of pasture to secondary forest was developed using the PCRaster Dynamic Modeling Package. This software provides a computer language specially developed for modeling temporal and spatial processes in a GIS, and is well suited for the development of ecological, dynamic models. The model of pasture conversion is implemented for the central Amazon. We assume that succession involves only three plant types: pasture grass, weeds and woody plants. The pasture grass is parameterized for Brachiaria (brizantha, humidicola), the weeds for Borreria and Rolandra, and the woody plants for Vismia spp. The model uses a 1m x 1m grid and 2-month time step. Each initial plant and each surviving propagule is referred to as a plant and only occupies one grid cell. A number of values are calculated for each grid cell for each time-step. These include whether vegetation is present and, if so, which species, the age of the species, the

  10. Seed deterioration in flooded agricultural fields during winter

    USGS Publications Warehouse

    Nelms, C.O.; Twedt, D.J.

    1996-01-01

    We determined rate of seed deterioration for 3 crops (corn, rice, and soybean) and 8 weeds commonly found in agricultural fields and moist-soil management units in the Mississippi Alluvial Valley (MAV). The weeds were broadleaf signalgrass (Brachiaria platyphylla), junglerice barnyardgrass (Echinochloa colonum), morningglory (Ipomoea sp.), panic grass (Panicum sp.), bull paspalum (Paspalum boscianum), red rice (Oryza sativa), hemp sesbania (Sesbania exaltata), and bristlegrass (Setaria sp.). Weed seeds, except morningglory, deteriorated slower than corn and soybean, whereas rice decomposed slower than all weed seeds except red rice and bull paspalum. For land managers desiring to provide plant food for wintering waterfowl, rice is clearly the most persistent small grain crop in the MAV. Persistence of weed seeds under flooded conditions throughout winter makes them a cost-effective alternative to traditional crops on land managed for waterfowl.

  11. Phytoremediation potential of paragrass--an in situ approach for chromium contaminated soil.

    PubMed

    Mohanty, Monalisa; Patra, Hemanta Kumar

    2012-09-01

    The present in situ phytoextraction approach uses paragrass (Brachiaria mutica (Forssk) Stapf) as a hyper accumulator for attenuation of chromium level in soil and mine waste water at South Kaliapani chromite mine area of Orissa. The bioconcentration factor (BCF) for Cr was maximum (0.334) in 100 days grown paragrass weeds. Transportation index (Ti) i.e. 6.16 and total accumulation rate (TAR) i.e. 8.2 mg kg(-1)day(-1) was maximum in 125 days old paragrass grown in Cr contaminated experimental cultivated plots. Cr bioaccumulation in roots was nearly 1000 times more than shoots. Paragrass showed luxuriant growth with massive fibrous roots when grown over Cr contaminated soils (11,170 mg/ kg dry soil). Cr bioaccumulation varies significantly with plant age, biomass and level of Cr contamination in irrigated mine waste water and soil. Paragrass could be used as hyperaccumulators as it showed rapid massive growth with a high tolerance to Cr.

  12. Is quality more important than quantity? Insect behavioural responses to changes in a volatile blend after stemborer oviposition on an African grass.

    PubMed

    Bruce, Toby J A; Midega, Charles A O; Birkett, Michael A; Pickett, John A; Khan, Zeyaur R

    2010-06-23

    Plants subjected to insect attack usually increase volatile emission which attracts natural enemies and repels further herbivore colonization. Less is known about the capacity of herbivores to suppress volatiles and the multitrophic consequences thereof. In our study, the African forage grass, Brachiaria brizantha, was exposed to ovipositing spotted stemborer, Chilo partellus, moths. A marked reduction in emission of the main volatile, (Z)-3-hexenyl acetate (Z3HA), occurred following oviposition but the ratio of certain other minor component volatiles to Z3HA was increased. While further herbivore colonization was reduced on plants after oviposition, the new volatile profile caused increased attraction of an adapted parasitoid, Cotesia sesamiae. Our results show that insect responses are dependent on the quality of volatile emission rather than merely the quantity in this multitrophic interaction.

  13. Changes in Biomass and Quality of Alpine Steppe in Response to N & P Fertilization in the Tibetan Plateau

    PubMed Central

    Dong, Junfu; Cui, Xiaoyong; Wang, Shuping; Wang, Fang; Pang, Zhe; Xu, Ning; Zhao, Guoqiang; Wang, Shiping

    2016-01-01

    In the alpine steppe zone on the Central Tibetan Plateau, a large amount of area has been degraded due to natural and artificial factors. N & P fertilization is widely accepted to recover degraded pastures in other regions all over the world. However, it is not clear how alpine steppe communities respond to N & P fertilization, and what is the optimal application rate, in the perspective of forage production. To attempt to explore these questions, in July 2013, two fencing sites were designed in Baingoin County with 12 treatments of different levels of nitrogen (N0: 0; N1: 7.5 g m-2 yr-1; N2: 15 g m-2 yr-1) & phosphate (P0: 0; P1: 7.5 gP2O5 m-2 yr-1; P2: 15 gP2O5 m-2 yr-1; P3: 30 gP2O5 m-2 yr-1). The results indicated N&P addition was capable to ameliorate the quality of the two sites in the Tibetan Plateau steppe. Increasing N application level resulted in significant increment in Gramineae and total biomass in the two sites. P addition significantly improved the quantity of Compositae, total biomass and the biomasss of other species in site II, while it only significantly improved the total biomass in site I. Gramineae was much more sensitive to N-induced changes than P-induced changes, and this indicated N addition was better to ameliorate the quality of plateau steppe than P-induced changes. No strong evidence was found for critical threshold within 15 g N m-2 yr-1, and there was decreasing tendency when P addition rate was above 15 g m-2 yr-1. N&P has the potential to accelerate soil acidification, which improved the content of available K, likely as a result of nonsignificant correlation between biomass and soil moisture. This work highlights the the tradeoffs that exist in N and P addition in recovering degraded steppe. PMID:27223104

  14. Holocene rapid climatic changes in the Okhotsk Sea and Amur watershed based on pollen analysis

    NASA Astrophysics Data System (ADS)

    Kokfelt, U.; Tiedemann, R.; Nuernberg, D.; Biebow, N.; Kozdon, R.; Lembke, L.; Kaiser, A.

    2003-04-01

    Recent investigations in the Sea of Okhotsk reveal high resolution records of rapid past climatic and vegetation pattern changes within this marginal sea and the adjacent Amur river drainage basin. The watershed of the Amur undergoes exteme seasonal as well as longer term climatic changes. A humid SE-Asia monsoon regime in summer is contrasted by cold, dry continental climate of Siberia in wintertime. Thus this region is crucial for our understanding of complex changes and shifts of athmospheric systems in the subarctic Far East and western North Pacific region. Gravity core LV28-4-4 was recovered from the continental margin off NE Sakhalin. Our age model consists of 16 AMS radiocarbon control points from planktic foraminifera and benthic shell fragments fit together by ninth order polynomial regressions. According to this, sedimentation rates exceed 100cm/kyr. Thus to date our investigations gain a temporal resolution of 200-600 years between discrete samples. We use analysis of terrestrial pollen and freshwater algae as proxies for vegetation changes in the Amur catchment area and the adjacent Siberian hinterland. Within this 930 cm long sequence, four pollen zones were distinguished: Pollen zone I (12,600-11,800 years BP), which comprises the Younger Dryas event, was dominated by non-arboreale taxa such as grasses (gramineae) and sedges (cyperaceae). The following pollen zone II (11,800-8,500 years BP) was in general dominated by birch (Betula) and elder (Alnus). The rise of spruce-dominated taiga (Picea jezoensis and P. glehnii) is clearly seen to the end of this zone and shows the preboreal warming. The oldest part of the pollen zone II has distinctly high values of birch and spruce and very low values of gramineae and cyperaceae suggesting a period of intense warming. Pollenzone III (8,500-3,600 years BP) is dominated by darkneedled taiga components and increased oak (Quercus) values and reflects the Holocene climatic optimum. The latest pollen zone IV

  15. Effects of hand weeding strip and nitrogen fertilizer on corn plants.

    PubMed

    da Silva, João Renato Vaz; Martins, Dagoberto; Cardoso, Leonildo A; Carbonari, Caio Antonio

    2005-01-01

    The objective of the present research was to evaluate effects of different strip weed control associated with nitrogen fertilizer on corn applied after planting. The experiment was set and conducted in Botucatu, São Paulo State, Brazil, and the hybrid planted was Dekalb 333-B. A completely randomized block design with four replications was used. Experimental plots were disposed as a factorial scheme 2 x 2 x 4, constituted by two types of weeding on row (with or without manual hoeing), two types of weeding on inter-row (with or without manual hoeing), and four nitrogen levels applied after planting (00, 60, 90, and 120 kg ha(-1)). Plots were composed by six rows with 5 m length. Nitrogen fertilizer was applied at 35 days after emergence (d.a.e). For weed community it was evaluated: weed density, dominancy, frequency, and relative importance. The main weed species were: Brachiaria plantiginea, Amaranthus retroflexus, Bidens pilosa, Cyperus rotunds, Brachiaria decumbens, Euphorbia heterofila, Oxalis latifolia, Acanthospermum hispidum, Commelina benghalensis. It was evaluated corn height at 40 and 100 d.a.e., first ear insertion height at 100 d.a.e., and final grain yield at harvesting. Plants and first ear insertion height were affected when nitrogen fertilizer was not applied. Treatments without weed control showed that weed interfered negatively with plants height. There were no correlation between weeds and nitrogen fertilizer for all parameters evaluated. Parcels without weed showed the highest ear weights and final grain production. Treatments that received nitrogen fertilizer, independently of studied arrangement, provided higher yields.

  16. Effects of biostimulation and nutritional supplementation on pubertal age and pregnancy rates of Nelore heifers (Bos indicus) in a tropical environment.

    PubMed

    Oliveira, C M G; Oliveira Filho, B D; Gambarini, M L; Viu, M A O; Lopes, D T; Sousa, A P F

    2009-07-01

    To determine effects of biostimulation (BIO) and dietary supplementation (BIO+S) on pubertal age and pregnancy rates, Nelore heifers (n=392) were randomly assigned to one of four treatment groups (n=98/group). All animals were in tropical environmental conditions, in the middle-west region of Brazil, grazing in pastures of Brachiaria brizantha, cv. Marandu; Panicum Maximum, cv. Tanzânia and Brachiaria humidícula. The heifers of the BIO group were kept in the presence of bulls while being maintained on pasture; the animals in the BIO+S group were kept in the presence of bulls while being managed on pasture and were fed a diet with greater energy and protein content to produce 0.49 kg of BW gain/day; the animals in control group (the NBIO) were kept away from bulls and under pasture conditions; and the animals in the NBIO+S group were kept away from bulls, were maintained on pasture, and were fed the same diet as the BIO+S group. Heifers were bred at 22-23 months of age, and pregnancy diagnosis was made 45 days after the end of the breeding season. There were differences (P<0.05) between groups regarding pubertal heifers up to 19 months (NPH), final body weight (FBW) and pregnancy rates (P<0.01), with an advantage for the animals in the BIO and BIO+S groups. Although the effect of a diet with greater protein and energy content was not clear in this experiment, the exposure of heifers to a male during the prepubertal period decreased age at the first breeding season, resulting in a significant reduction in age of first pregnancy in Nelore heifers kept under extensive management systems in a tropical environment.

  17. Morpho-anatomical adaptations to waterlogging by germplasm accessions in a tropical forage grass

    PubMed Central

    Cardoso, Juan Andrés; Rincón, Joisse; Jiménez, Juan de la Cruz; Noguera, Diana; Rao, Idupulapati M.

    2013-01-01

    Soil waterlogging reduces gas exchange between the soil and the atmosphere, leading to oxygen deprivation in the rhizosphere. Brachiaria spp. are the most widely sown forage grasses in tropical America. Among commercial Brachiaria grasses, B. humidicola shows superior tolerance to waterlogged soils based on maintenance of growth and reduced leaf chlorophyll loss and senescence. However, little is known about the underlying traits of waterlogging tolerance in B. humidicola or their intraspecific variation. For this purpose, an outdoor study was conducted using 12 germplasm accessions of B. humidicola that were grown in soil cylinders under drained or waterlogged soil conditions for 21 days. Dry mass production and morpho-anatomical responses (aerenchyma in shoots and roots, root diameter, proportional area of stele in roots, number of nodal and lateral roots, and length of the longest root) were determined. All accessions showed shorter roots and reduced root dry mass under waterlogged soil conditions. All accessions showed aerenchyma in shoots and roots under drained conditions but were further increased under waterlogging. All accessions showed a reduction in the proportional area of stele of roots in response to waterlogging. The accession (CIAT 26570) that showed a higher proportion of aerenchyma in shoots and roots and an increased number of nodal roots (with higher diameter and a reduction in the number of lateral roots) showed longer roots, less reduction in root dry mass and increased shoot growth under waterlogged conditions. We conclude that superior growth of one accession (CIAT 26570) under waterlogged soil conditions is probably a result of morpho-anatomical traits acting together to enhance root aeration and shoot ventilation. Further research is needed to test the ability to recover from waterlogging in B. humidicola accessions.

  18. A comparative study on hulled adlay and unhulled adlay through evaluation of their LPS-induced anti-inflammatory effects, and isolation of pure compounds.

    PubMed

    Choi, Goeun; Han, Ah-Reum; Lee, Joo Hee; Park, Ji-Youn; Kang, Unwoo; Hong, Jongki; Kim, Yeong Shik; Seo, Eun-Kyoung

    2015-03-01

    Coicis semen (=the hulled seed of Coix lacryma-jobi L. var. ma-yuen (Rom.Caill.) Stapf; Gramineae), commonly known as adlay and Job's tears, is widely used in traditional medicine and as a nutritious food. Bioassay-guided fractionation of the AcOEt fraction of unhulled adlays, using measurement of nitric oxide (NO) production on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells, led to the isolation and identification of two new stereoisomers, (+)-(7'S,8'R,7″S,8″R)-guaiacylglycerol β-O-4'-dihydrodisinapyl ether (1) and (+)-(7'S,8'R,7″R,8″R)-guaiacylglycerol β-O-4'-dihydrodisinapyl ether (2), together with six known compounds, 3-8. Compounds 3 and 4 exhibited inhibitory activities on LPS-induced NO production with IC50 values of 1.4 and 3.7 μM, respectively, and suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expressions in RAW 264.7 macrophage cells. Simple high-performance liquid chromatography with ultraviolet detection (HPLC/UV) was used to compare the AcOEt fraction of unhulled adlays responsible for the anti-inflammatory activity in RAW 264.7 cells and the inactive AcOEt fraction of hulled adlays.

  19. Chiral response of Oryzeae and Paniceae plants in alpha-methylbenzyl-3-p-tolyl urea agar medium.

    PubMed

    Omokawa, Hiroyoshi; Murata, Hiroshi; Kobayashi, Shoko

    2004-01-01

    The results presented here support the hypothesis that plants of the tribe Oryzeae respond enantioselectively and homogeneously to optically active 1-alpha-methylbenzyl-3-p-tolylurea (MBTU) in root growth inhibition, in contrast to Echinochloa species. The Oryzeae plants tested in this study belong to different genera (Oryza, Leersia, Chikusichloa and Zizania), to different species (O sativa, O glaberrima, O alta, O coarctata, O latifolia, O minuta, O rufipogon), to various ecospecies of Oryza (japonica, indica, japonica x indica, javanica) and to different levels of evolution [cultivated rice (O sativa and O glaberrima) and ancestral wild rice species]. In spite of their different phylogenic status and diverse sensitivity, the root growth of all members of the genus Oryza was inhibited more by R-MBTU than by S-MBTU. Zizania palustris, Z latifolia, Leersia oryzoides and Chikusichloa aquatica belonging to the tribe Oryzeae exhibited similar chiral recognition to the Oryza plants, suggesting that Oryzeae have a common chiral recognition mechanism in their response to optically active MBTUs. In contrast, Echinochloa plants (E crus-galli (L) Beauv var crus-galli and E colonum (L) Link), belonging into subfamily Panicoideae tribe Paniceae, responded in a different way, where their root growth was more sensitive to S-MBTU than to the antipodal R-MBTU. A reverse chiral response between the tribe Oryzeae and the genus Echinochloa was clearly indicated in this study. This diverse response may be relevant to Gramineae classification.

  20. Mechanism and capacities of reducing ecological cost through rice–duck cultivation

    PubMed Central

    Long, Pan; Huang, Huang; Liao, Xiaolan; Fu, Zhiqiang; Zheng, Huabin; Chen, Aiwu; Chen, Can

    2013-01-01

    BACKGROUND: Rice–duck cultivation is the essence of Chinese traditional agriculture. A scientific assessment of the mechanism and its capacity is of theoretical significance and practical value in improving modern agricultural technology. RESULTS: The duck’s secretions, excreta and their treading, pecking and predation decrease the occurrence of plant diseases, pests and weeds, enrich species diversity and improve the field environment. The rice–duck intergrowth system effectively prevents rice planthoppers and rice leafhoppers. The control effects can be up to 98.47% and 100% respectively; it also has effects on the control of Chilo suppressalis, Tryporyza incertulas and the rice leafrollers. Notable control results are found on sheath blight, while the effects on other diseases are about 50%. Harm from weeds is placed under primary control; prevention of weeds is sequenced by broadleaf weeds > sedge weeds > Gramineae weeds. Contents of soil organic matter, N, P and K are improved by the system; nutrient utilization is accelerated, resulting in decreased fertilizer application. Greenhouse gas emissions are reduced by 1–2% and duck fodder is saved in this system. There is also an obvious economic benefit. CONCLUSION: Compared to conventional rice cultivation, rice–duck cultivation shows great benefits to ecologic cost and economic income. © 2013 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:23703299

  1. Airborne pollen grains in Bursa, Turkey, 1999-2000,.

    PubMed

    Bicakci, Adem; Tatlidil, Sevcan; Sapan, Nihat; Malyer, Hulusi; Canitez, Yakup

    2003-01-01

    In this study, pollen grains were sampled by using a Lanzoni trap (Lanzoni VPPS 2000) in atmosphere of Bursa in 1999 and 2000. During two years. a total of 13,991 pollen grains/m3 which belonged to 59 taxa and unidentified pollen grains were recorded. A total of 7.768 pollen grains were identified in 1999 and a total of 6.223 in 2000. From these taxa, 36 belong to arboreal and 23 taxa to non-arboreal plants. Total pollen grains consist of 78.61% arboreal. 20.37% non-arboreal plants and 1.03% unidentified pollen grains. In the region investigated, Pinus sp., Olea sp., Platanus sp., Gramineae, Cupressaceae/Taxaceae, Quercus sp., Acer sp.. Morus sp. Xanthium sp., Castanea sp., Chenopodiaceae/Amaranthaceae, Corvlus sp., Artemisia sp., Urtica sp.and Fraxinus sp. were responsible for the greatest amounts of pollen. During the study period the pollen concentration reached its highest level in April.

  2. Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation

    USGS Publications Warehouse

    Ager, T.A.; Matthews, J.V.; Yeend, W.

    1994-01-01

    Gravels deposited by the ancestral Yukon River are preserved in terrace remnants on the margins of the Yukon River valley near the village of Circle in east-central Alaska. Plant fossils recovered from sandy silt lenses within these gravels include cones and needles of Picea and Larix and a variety of seeds. Seed types include several taxa which no longer grow in Alaska, such as Epipremnum, Prunus and Weigela. Pollen types recovered from these deposits represent tree and shrub taxa that grow in interior Alaska today, such as Picea, Larix, Betula and Alnus, as well as several taxa that no longer grow in interior Alaska today, such as Pinus, Tsuga, Abies and Corylus. Pollen of herb taxa identified include Gramineae, Cyperaceae, Caryophyllaceae, Compositae, Polemonium and Epilobium. The fossil flora from the gravels near Circle are similar and probably age-equivalent to the flora recovered from the Nenana Gravel in the Alaska Range 250 km to the south. Palynological and tectonic evidence summarized in this paper now suggests that the Nenana Gravel was deposited during the early and middle Pliocene. The presence of plant fossils of Tsuga, Abies, Pinus, Weigela and Prunus suggests that the mean annual temperature (MAT) of eastern interior Alaska during the early and middle Pliocene was perhaps 7-9??C warmer and less continental than today's MAT of -6.4??C. ?? 1994.

  3. Late Pleistocene and Holocene Beringia vegetation dynamic reconstructions based on a yedoma exposure, Itkillik (Alaska)

    NASA Astrophysics Data System (ADS)

    Lapointe Elmrabti, L.; Fortier, D.; Shur, Y.; Kanevskiy, M. Z.; Talbot, J.

    2013-12-01

    The Itkillik river area in Alaska (69°34‧ N, 150°52‧W), is part of the loosely defined region of Beringia, which was largely unglaciated during the last ice age. Beringia is known to have acted as a refugium for boreal trees and shrubs during the Pleistocene, but questions remain about the environmental history of North-Eastern Beringia, especially the extent and dynamics of the now extinct tundra-steppe biome. The 33-m-high Itkillik river exposure formed over the late Pleistocene / early Holocene (48,000 to 5,000 14C yr BP) and the exposed eolian sediments are largely undisturbed, offering a unique opportunity to examine a long term vegetation sequence in high latitude environment and link the vegetation reconstructions with the sedimentology and cryostratigraphy of the region. Because of the very low concentration of pollen in the sediments, we utilized an extraction method based on heavy-liquid (Sodium Polytungstate (SPT)) separation. Our results show a tundra-steppe vegetation type, characterized by the abundance of cyperacea and graminea taxa. Overall the pollen record of the Itkillik exposure will provide an important point of comparison to other sites localised in the circumpolar circle, especially in Siberia, as yedoma remains one of the most noticeable structures of the cold and dry periglacial environment of the Arctic and subarctic east Siberia. Implications of our findings for local climate reconstructions using pollen-climate transfer functions are discussed.

  4. Isoeugenin, a Novel Nitric Oxide Synthase Inhibitor Isolated from the Rhizomes of Imperata cylindrica.

    PubMed

    An, Hyo-Jin; Nugroho, Agung; Song, Byong-Min; Park, Hee-Juhn

    2015-12-01

    Phytochemical studies on the constituents of the rhizomes of Imperata cylindrica (Gramineae) were performed using high-performance liquid chromatography (HPLC). We also aimed to search for any biologically active substance capable of inhibiting nitric oxide (NO) formation in lipopolysaccharide (LPS)-activated macrophage 264.7 cells, by testing four compounds isolated from this plant. Four compounds, including a new chromone, isoeugenin, along with ferulic acid, p-coumaric acid, and caffeic acid were isolated and identified by NMR spectroscopy. The structure of isoeugenin was determined as 7-hydroxy-5-methoxy-2-methylchromone by the 2D-NMR technique. Among the four compounds, isoeugenin has the lowest IC50 value on the inhibition of NO production in LPS-activated macrophage RAW264.7 cells (IC50, 9.33 μg/mL). In addition, isoeugenin significantly suppressed the LPS-induced expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines mRNA levels. Taken together, these results suggest that the anti-inflammatory activity of isoeugenin is associated with the down-regulation of iNOS, COX-2, and pro-inflammatory cytokines in RAW264.7 cells. Accordingly, our results suggest that the new chromone isoegenin should be considered a potential treatment for inflammatory disease.

  5. Comparative anti-hyperglycemic potentials of medicinal plants.

    PubMed

    Villaseñor, Irene M; Lamadrid, Mary Rose A

    2006-03-08

    Validation of the ethnobotanical use of the leaves of Artemisia vulgaris Linn. (Compositae), Eucalyptus tereticornis Sm. (Myrtaceae), Solanum nigrum Linn. (Solanaceae), and Vitex negundo Linn. (Verbenaceae); stems of Nopalea cochinellifera (Linn.) Salm-Dyck (Cactaceae); roots of Imperata cylindrica Beauv. (Gramineae); dried bark of Syzygium cumini (Linn.) Skeels (Myrtaceae) as anti-diabetic agents using the oral glucose tolerance test showed that only the bark of Syzygium cumini and the leaves of Vitex negundo and Eucalyptus tereticornis exhibited anti-hyperglycemic activities when fed simultaneously with glucose. At the same dosages of 5 mg/20 g mouse, Syzygium cumini-treated mice showed a significant decrease in blood glucose levels (BGLs) at 30 min (alpha=0.10) and from 45 min onwards at alpha=0.05. Vitex negundo exhibited greater anti-hyperglycemic activity than Eucalyptus tereticornis. Both showed a significant decrease in BGLs at 60 min but at alpha=0.05 for Vitex negundo and at alpha=0.07 for Eucalyptus tereticornis. There was no significant lowering in BGLs for Imperata cylindrica and Solanum nigrum while there was even an increase in BGLs for Nopalea cochinellifera and Artemisia vulgaris.

  6. Response of aboveground biomass and diversity to nitrogen addition – a five-year experiment in semi-arid grassland of Inner Mongolia, China

    PubMed Central

    He, Kejian; Qi, Yu; Huang, Yongmei; Chen, Huiying; Sheng, Zhilu; Xu, Xia; Duan, Lei

    2016-01-01

    Understanding the response of the plant community to increasing nitrogen (N) deposition is helpful for improving pasture management in semi-arid areas. We implemented a 5-year N addition experiment in a Stipa krylovii steppe of Inner Mongolia, northern China. The aboveground biomass (AGB) and species richness were measured annually. Along with the N addition levels, the species richness declined significantly, and the species composition changed noticeably. However, the total AGB did not exhibit a noticeable increase. We found that compensatory effects of the AGB occurred not only between the grasses and the forbs but also among Gramineae species. The plant responses to N addition, from the community to species level, lessened in dry years compared to wet or normal years. The N addition intensified the reduction of community productivity in dry years. Our study indicated that the compensatory effects of the AGB among the species sustained the stability of grassland productivity. However, biodiversity loss resulting from increasing N deposition might lead the semi-arid grassland ecosystem to be unsustainable, especially in dry years. PMID:27573360

  7. Mastodon herbivory in mid-latitude late-Pleistocene boreal forests of eastern North America

    NASA Astrophysics Data System (ADS)

    Teale, Chelsea L.; Miller, Norton G.

    2012-07-01

    Skeletal remains of the extinct American mastodon have often been found with deposits of short, decorticated twigs intermixed with plant fragments presumed to be gastrointestinal or fecal material. If such deposits are digesta, paleobotanical evidence may be used to analyze mastodon foraging strategy, with implications for assessing habitat selection, ecological roles, and response to environmental change. To identify components of mastodon diet in mid-latitude late-Pleistocene boreall forests of eastern North America, plant macrofossils and pollen from a molar socket (Hyde Park site, New York) were compared with dispersed deposits associated with skeletal remains (Hiscock and Chemung sites, New York). Similar macrofossil condition and twig morphology among samples, but difference from a modern boreal fen analog, confirmed the deposits were digesta. Comparison of twigs with material from other paleontological sites and modern elephants suggested dimensions generally indicative of digesta. Picea formed the bulk of each sample but Pinus may have been locally important. Wintertime browsing of Salix and Populus, and springtime consumption of Alnus, were indicated. Evidence for Cyperaceae, Gramineae, and Compositae was ambiguous. If conifers, broadleaf trees, shrubs, and herbs were necessary to fulfill dietary requirements, mastodons would have been nutritionally stressed by rapid late-Pleistocene decrease in vegetational diversity.

  8. Population Dynamics of a Commercial Sponge in Biscayne Bay, Florida

    NASA Astrophysics Data System (ADS)

    Cropper, W. P.; Lirman, D.; Tosini, S. C.; DiResta, D.; Luo, J.; Wang, J.

    2001-07-01

    The dynamics of glove sponge ( Spongia graminea) population in Biscayne Bay, Florida were investigated using a series of matrix population models, a hydrodynamic model, and a GIS data base. Sponges at Billy's Point, on the eastern margin of Biscayne Bay, were sampled between 1993 and 1995 and resampled in 2000 for model calibration and testing. An iterative procedure was used to fit unmeasured fecundity and a growth parameter by minimizing the 1993 to 2000 simulated differences from the observed year 2000 size class distribution. A density dependent model was found to fit the total population size in 2000 better than the density independent matrix model. Systematic sampling of the bay was used to identify four local populations with sponge densities above 50 ha -1. The three western populations experienced salinity below 25, based on hydrodynamic model outputs for 1995, whereas the eastern Billy's Point population had a stable ocean salinity environment. The hydrodynamic model was used to simulate larval transport between local populations as lagrangian drifting particles. These simulations indicated that the Billy's Point population was likely to be demographically closed.

  9. Discovery and analysis of microRNAs in Leymus chinensis under saline-alkali and drought stress using high-throughput sequencing.

    PubMed

    Zhai, Junfeng; Dong, Yuanyuan; Sun, Yepeng; Wang, Qi; Wang, Nan; Wang, Fawei; Liu, Weican; Li, Xiaowei; Chen, Huan; Yao, Na; Guan, Lili; Chen, Kai; Cui, Xiyan; Yang, Meiying; Li, Haiyan

    2014-01-01

    Leymus chinensis (Trin.) Tzvel. is a perennial rhizome grass of the Poaceae (also called Gramineae) family, which adapts well to drought, saline and alkaline conditions. However, little is known about the stress tolerance of L. chinensis at the molecular level. microRNAs (miRNAs) are known to play critical roles in nutrient homeostasis, developmental processes, pathogen responses, and abiotic stress in plants. In this study, we used Solexa sequencing technology to generate high-quality small RNA data from three L. chinensis groups: a control group, a saline-alkaline stress group (100 mM NaCl and 200 mM NaHCO3), and a drought stress group (20% polyethylene glycol 2000). From these data we identified 132 known miRNAs and 16 novel miRNAs candidates. For these miRNAs we also identified target genes that encode a broad range of proteins that may be correlated with abiotic stress regulation. This is the first study to demonstrate differentially expressed miRNAs in L. chinensis under saline-alkali and drought stress. These findings may help explain the saline-alkaline and drought stress responses in L. chinensis.

  10. Colocalization of barley lectin and sporamin in vacuoles of transgenic tobacco plants

    SciTech Connect

    Schroeder, M.R.; Borkhsenious, O.N.; Raikhel, N.V. ); Matsuoka, K.; Nakamura, K. )

    1993-02-01

    Various targeting motifs have been identified for plant proteins delivered to the vacuole. For barley (Hordeum vulgare) lectin, a typical Gramineae lectin and defense-related protein, the vacuolar information is contained in a carboxyl-terminal propeptide. In contrast, the vacuolar targeting information of sporamin, a storage protein from the tuberous roots of the sweet potato (Ipomoea batatas), is encoded in an amino-terminal propeptide. Both proteins were expressed simultaneously in transgenic tobacco plants to enable analysis of their posttranslational processing and subcellular localization by pulse-chase labeling and electron-microscopic immunocytochemical methods. The pulse-chase experiments demonstrated that processing and delivery to the vacuole are not impaired by the simultaneous expression of barley lectin and sporamin. Both proteins were targeted quantitatively to the vacuole, indication that the carboxyl-terminal and amino-terminal propeptided are equally recognized by the vacuolar protein-sorting machinery. Double-labeling experiments showed that barley lectin and sporamin accumulate in the same vacuole of transgenic tobacco (Nicotiana tabacum) leaf and root cells. 35 refs., 5 figs., 3 tabs.

  11. Transferability of retrotransposon primers derived from Persimmon (Diospyros kaki Thunb.) across other plant species.

    PubMed

    Du, X Y; Hu, Q N; Zhang, Q L; Wang, Y B; Luo, Z R

    2013-06-06

    Retrotransposon-based molecular markers are powerful molecular tools. However, these markers are not readily available due to the difficulty in obtaining species-specific retrotransposon primers. Although recent techniques enabling the rapid isolation of retrotransposon sequences have facilitated primer development, this process nonetheless remains time-consuming and costly. Therefore, research into the transferability of retrotransposon primers developed from one plant species onto others would be of great value. The present study investigated the transferability of retrotransposon primers derived from 'Luotian-tianshi' persimmon (Diospyros kaki Thunb.) across other fruit crops, as well as within the genus using inter-retrotransposon amplified polymorphism molecular marker. Fourteen of the 26 retrotransposon primers tested (53.85%) produced robust and reproducible amplification products across all fruit crops tested, indicating their applicability across plant species. Four of the 13 fruit crops showed the best transferability performances: persimmon, grape, citrus, and peach. Furthermore, similarity coefficients and UPGMA clustering indicated that these primers could further offer a potential tool for germplasm differentiation, parentage identification, genetic diversity assessment, classification, and phylogenetic studies across a variety of plant species. Transferability was further confirmed by examining published primers derived from Rosaceae, Gramineae, and Solanaceae. This study is one of the few currently available studies concerning the transferability of retrotransposon primers across plant species in general, and is the first successful study of the transferability of retrotransposon primers derived from persimmon. The primers presented here will help reduce costs for future retrotransposon primer development and therefore contribute to the popularization of retrotransposon molecular markers.

  12. Application of yeast glycolipid biosurfactant, mannosylerythritol lipid, as agrospreaders.

    PubMed

    Fukuoka, Tokuma; Yoshida, Shigenobu; Nakamura, Junichi; Koitabashi, Motoo; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai; Kitamoto, Hiroko

    2015-01-01

    The spreading property of mannosylerythritol lipids (MELs) was investigated in connection with our search for new application in agriculture. The wetting ability of MEL solutions for hydrophobic surfaces was evaluated based on contact angle measurements for several surfactant solutions on abiotic and biotic surfaces. The contact angle of MEL-A solution on a hydrophobic plastic surface at 100 s after placement decreased to 8.4°, and those of other MEL solutions decreased more significantly compared to those of commonly-used nonionic surfactants. In addition, the contact angle of MEL solutions also dropped down to around 10° on various plant leaf surfaces. MEL solutions, in particular, efficiently spread even on poorly wettable Gramineae plant surfaces on which general nonionic surfactant solutions could not. Moreover, the wetting ability of MEL solutions was found to be greatly affected by the structural difference in their carbohydrate configuration. Furthermore, surface pretreatment with MEL solution led to more efficient spreading and fixing of microbial cells onto plant leaf surface compared to several conventional surfactants used in this study. These results suggested that MELs have a potential to use as a natural bio-based spreading agent, particularly as agrochemical spreader for biopesticides.

  13. Microbial hitchhikers on intercontinental dust: catching a lift in Chad

    PubMed Central

    Favet, Jocelyne; Lapanje, Ales; Giongo, Adriana; Kennedy, Suzanne; Aung, Yin-Yin; Cattaneo, Arlette; Davis-Richardson, Austin G; Brown, Christopher T; Kort, Renate; Brumsack, Hans-Jürgen; Schnetger, Bernhard; Chappell, Adrian; Kroijenga, Jaap; Beck, Andreas; Schwibbert, Karin; Mohamed, Ahmed H; Kirchner, Timothy; de Quadros, Patricia Dorr; Triplett, Eric W; Broughton, William J; Gorbushina, Anna A

    2013-01-01

    Ancient mariners knew that dust whipped up from deserts by strong winds travelled long distances, including over oceans. Satellite remote sensing revealed major dust sources across the Sahara. Indeed, the Bodélé Depression in the Republic of Chad has been called the dustiest place on earth. We analysed desert sand from various locations in Chad and dust that had blown to the Cape Verde Islands. High throughput sequencing techniques combined with classical microbiological methods showed that the samples contained a large variety of microbes well adapted to the harsh desert conditions. The most abundant bacterial groupings in four different phyla included: (a) Firmicutes—Bacillaceae, (b) Actinobacteria—Geodermatophilaceae, Nocardiodaceae and Solirubrobacteraceae, (c) Proteobacteria—Oxalobacteraceae, Rhizobiales and Sphingomonadaceae, and (d) Bacteroidetes—Cytophagaceae. Ascomycota was the overwhelmingly dominant fungal group followed by Basidiomycota and traces of Chytridiomycota, Microsporidia and Glomeromycota. Two freshwater algae (Trebouxiophyceae) were isolated. Most predominant taxa are widely distributed land inhabitants that are common in soil and on the surfaces of plants. Examples include Bradyrhizobium spp. that nodulate and fix nitrogen in Acacia species, the predominant trees of the Sahara as well as Herbaspirillum (Oxalobacteraceae), a group of chemoorganotrophic free-living soil inhabitants that fix nitrogen in association with Gramineae roots. Few pathogenic strains were found, suggesting that African dust is not a large threat to public health. PMID:23254516

  14. Global warming and allergy in Asia Minor.

    PubMed

    Bajin, Munir Demir; Cingi, Cemal; Oghan, Fatih; Gurbuz, Melek Kezban

    2013-01-01

    The earth is warming, and it is warming quickly. Epidemiological studies have demonstrated that global warming is correlated with the frequency of pollen-induced respiratory allergy and allergic diseases. There is a body of evidence suggesting that the prevalence of allergic diseases induced by pollens is increasing in developed countries, a trend that is also evident in the Mediterranean area. Because of its mild winters and sunny days with dry summers, the Mediterranean area is different from the areas of central and northern Europe. Classical examples of allergenic pollen-producing plants of the Mediterranean climate include Parietaria, Olea and Cupressaceae. Asia Minor is a Mediterranean region that connects Asia and Europe, and it includes considerable coastal areas. Gramineae pollens are the major cause of seasonal allergic rhinitis in Asia Minor, affecting 1.3-6.4 % of the population, in accordance with other European regions. This article emphasizes the importance of global climate change and anticipated increases in the prevalence and severity of allergic disease in Asia Minor, mediated through worsening air pollution and altered local and regional pollen production, from an otolaryngologic perspective.

  15. Genetic Divergence of an Avian Endemic on the Californian Channel Islands.

    PubMed

    Wilson, Amy G; Chan, Yvonne; Taylor, Sabrina S; Arcese, Peter

    2015-01-01

    The Californian Channel Islands are near-shore islands with high levels of endemism, but extensive habitat loss has contributed to the decline or extinction of several endemic taxa. A key parameter for understanding patterns of endemism and demography in island populations is the magnitude of inter-island dispersal. This paper estimates the extent of migration and genetic differentiation in three extant and two extinct populations of Channel Island song sparrows (Melospiza melodia graminea). Inter-island differentiation was substantial (G''ST: 0.14-0.37), with San Miguel Island having the highest genetic divergence and lowest migration rates. Santa Rosa and Santa Cruz Island populations were less diverged with higher migration rates. Genetic signals of past population declines were detected in all of the extant populations. The Channel Island populations were significantly diverged from mainland populations of M. m. heermanni (G''ST: 0.30-0.64). Ten mtDNA haplotypes were recovered across the extant and extinct Channel Island population samples. Two of the ten haplotypes were shared between the Northern and Southern Channel Islands, with one of these haplotypes being detected on the Californian mainland. Our results suggest that there is little contemporary migration between islands, consistent with early explanations of avian biogeography in the Channel Islands, and that song sparrow populations on the northern Channel Islands are demographically independent.

  16. Response of AM fungi spore population to elevated temperature and nitrogen addition and their influence on the plant community composition and productivity

    PubMed Central

    Zhang, Tao; Yang, Xue; Guo, Rui; Guo, Jixun

    2016-01-01

    To examine the influence of elevated temperature and nitrogen (N) addition on species composition and development of arbuscular mycorrhizal fungi (AMF) and the effect of AMF on plant community structure and aboveground productivity, we conducted a 5-year field experiment in a temperate meadow in northeast China and a subsequent greenhouse experiment. In the field experiment, N addition reduced spore population diversity and richness of AMF and suppressed the spore density and the hyphal length density (HLD). Elevated temperature decreased spore density and diameter and increased the HLD, but did not affect AMF spore population composition. In the greenhouse experiment, AMF altered plant community composition and increased total aboveground biomass in both elevated temperature and N addition treatments; additionally, AMF also increased the relative abundance and aboveground biomass of the grasses Leymus chinensis (Poaceae) and Setaria viridis (Gramineae) and significantly reduced the relative abundance and aboveground biomass of the Suaeda corniculata (Chenopodiaceae). Although elevated temperature and N addition can affect species composition or suppress the development of AMF, AMF are likely to play a vital role in increasing plant diversity and productivity. Notably, AMF might reduce the threat of climate change induced degradation of temperate meadow ecosystems. PMID:27098761

  17. Evolutionarily Distinct BAHD N-Acyltransferases Are Responsible for Natural Variation of Aromatic Amine Conjugates in Rice[OPEN

    PubMed Central

    Peng, Meng; Chen, Wei; Wang, Wensheng; Shen, Shuangqian; Shi, Jian; Wang, Cheng; Zhang, Yu; Zou, Li; Wang, Shouchuang; Wan, Jian; Liu, Xianqing; Gong, Liang; Luo, Jie

    2016-01-01

    Phenolamides (PAs) are specialized (secondary) metabolites mainly synthesized by BAHD N-acyltransferases. Here, we report metabolic profiling coupled with association and linkage mapping of 11 PAs in rice (Oryza sativa). We identified 22 loci affecting PAs in leaves and 16 loci affecting PAs in seeds. We identified eight BAHD N-acyltransferases located on five chromosomes with diverse specificities, including four aromatic amine N-acyltransferases. We show that genetic variation in PAs is determined, at least in part, by allelic variation in the tissue specificity of expression of the BAHD genes responsible for their biosynthesis. Tryptamine hydroxycinnamoyl transferase 1/2 (Os-THT1/2) and tryptamine benzoyl transferase 1/2 (Os-TBT1/2) were found to be bifunctional tryptamine/tyramine N-acyltransferases. The specificity of Os-THT1 and Os-TBT1 for agmatine involved four tandem arginine residues, which have not been identified as specificity determinants for other plant BAHD transferases, illustrating the versatility of plant BAHD transferases in acquiring new acyl acceptor specificities. With phylogenetic analysis, we identified both divergent and convergent evolution of N-acyltransferases in plants, and we suggest that the BAHD family of tryptamine/tyramine N-acyltransferases evolved conservatively in monocots, especially in Gramineae. Our work demonstrates that omics-assisted gene-to-metabolite analysis provides a useful tool for bulk gene identification and crop genetic improvement. PMID:27354554

  18. [Sensitization to pollen in the asthmatic child. A study of 86 cases].

    PubMed

    Zouari, Samia; Khaldi, Faouzia

    2006-08-01

    This retrospective study was designed to determine the place of pollen sensibilization in asthmatic child and to assess its epidemiological and clinical characteristics. 86 from 638 asthmatic child were allergic to pollen and included in the study. The mean age was 4 years (extremes : 1-12 years). The mean age of first respiratory manifestations was 1 and half years. The male/female ratio was 1.46. Asthmatic attacks was noted in 77% of cases, chronic cough was the only allergic manifestation in 16% of cases. Associated rhinitis or conjunctivitis were found in 55% of cases, atopic dermatitis was found in 4 patients (4.6% of cases). Atopic asthma was per annual in 78% of cases. Pollinic asthma was diagnosed in 51 child. Other sensibilization were found in 60% of cases. 26 child (32%) were allergic to pollen only and 18 child to sample pollen. The gramineae pollen sensibilization is the most common allergy, followed by olive tree and cypress tree and herbaceous pollens.

  19. Cross-reactivity to olive tree pollen and orchard grass pollen in patients with pollinosis.

    PubMed

    Miyahara, S; Nakada, M; Nishizaki, K; Kawarai, Y; Nishioka, K; Hino, H

    1997-06-01

    We studied 92 patients with allergic rhinitis in Syodoshima, Japan, during the pollen season between April and June to evaluate the cross-reactivity to different antigens, including pollen from the olive tree (Olea europaea) and orchard grass (Dactylis glomerata). Olive tree pollen was present in the atmosphere for 23 days, from May 19 to June 12, 1994. Specific IgE antibodies for olive tree pollen antigen were present in 21 (26.9%) of the 78 patients with allergic rhinitis. Nine (24.3%) of the 37 patients with allergic rhinitis exhibited positive skin reactivity to an extract of olive tree pollen. Fifteen (88.2%) of the 17 patients who had IgE reactivity in their sera to olive tree pollen antigen demonstrated allergic reactions to an extract of olive tree pollen. Specific IgE antibodies for orchard grass pollen antigen were present in 43 (48.3%) of the 89 patients with allergic rhinitis and 20 (95.2%) of the 21 patients who had IgE reactivity in their sera to olive tree pollen antigen. The inhibition test using the CAP System revealed that the reactivity of the IgE antibody specific for olive tree pollen antigen was inhibited dose-dependently by an extract of orchard grass pollen. These findings show that there is a reaction in some patients with grass (Gramineae) pollinosis that might be induced by olive tree pollen.

  20. Microbial hitchhikers on intercontinental dust: catching a lift in Chad.

    PubMed

    Favet, Jocelyne; Lapanje, Ales; Giongo, Adriana; Kennedy, Suzanne; Aung, Yin-Yin; Cattaneo, Arlette; Davis-Richardson, Austin G; Brown, Christopher T; Kort, Renate; Brumsack, Hans-Jürgen; Schnetger, Bernhard; Chappell, Adrian; Kroijenga, Jaap; Beck, Andreas; Schwibbert, Karin; Mohamed, Ahmed H; Kirchner, Timothy; de Quadros, Patricia Dorr; Triplett, Eric W; Broughton, William J; Gorbushina, Anna A

    2013-04-01

    Ancient mariners knew that dust whipped up from deserts by strong winds travelled long distances, including over oceans. Satellite remote sensing revealed major dust sources across the Sahara. Indeed, the Bodélé Depression in the Republic of Chad has been called the dustiest place on earth. We analysed desert sand from various locations in Chad and dust that had blown to the Cape Verde Islands. High throughput sequencing techniques combined with classical microbiological methods showed that the samples contained a large variety of microbes well adapted to the harsh desert conditions. The most abundant bacterial groupings in four different phyla included: (a) Firmicutes-Bacillaceae, (b) Actinobacteria-Geodermatophilaceae, Nocardiodaceae and Solirubrobacteraceae, (c) Proteobacteria-Oxalobacteraceae, Rhizobiales and Sphingomonadaceae, and (d) Bacteroidetes-Cytophagaceae. Ascomycota was the overwhelmingly dominant fungal group followed by Basidiomycota and traces of Chytridiomycota, Microsporidia and Glomeromycota. Two freshwater algae (Trebouxiophyceae) were isolated. Most predominant taxa are widely distributed land inhabitants that are common in soil and on the surfaces of plants. Examples include Bradyrhizobium spp. that nodulate and fix nitrogen in Acacia species, the predominant trees of the Sahara as well as Herbaspirillum (Oxalobacteraceae), a group of chemoorganotrophic free-living soil inhabitants that fix nitrogen in association with Gramineae roots. Few pathogenic strains were found, suggesting that African dust is not a large threat to public health.

  1. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water.

    PubMed

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-11-26

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant's ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters.

  2. Transfer of metals to plants and red deer in an old lead mining area in Spain.

    PubMed

    Reglero, M M; Monsalve-González, L; Taggart, M A; Mateo, R

    2008-11-15

    Lead mining in the Sierra Madrona mountains and the valley of Alcudia in Southern Spain began in the 1st millennium B.C., and the area was intermittently exploited up until the end of the 20th century. The degree of contamination by Pb, Zn, Cd, Cu, As and Se of soil, water and sediment, and the transfer to 13 species of plants, and then to red deer (Cervus elaphus) have been studied. Mined areas had higher concentrations in stream sediments than control areas. The highest concentrations were observed for Pb (1481 microg g(-1) d.w.) and As (1880 microg g(-1)) in the sediment of a stream flowing beside the spoil dump at Mina de Horcajo. Plants from mining sites contained consistently higher levels of Pb and As, and their concentrations in plants were correlated. The highest concentrations of Pb were in Gramineae (Pb: 97.5, As: 2.4 microg g(-1) d.w.), and the lowest in elmleaf blackberry (Rubus ulmifolius). The highest mean liver concentrations were found in red deer from the mining sites for Pb (0.805 microg g(-1) d. w.), Cd (0.554 microg g(-1)), Se (0.327 microg g(-1)), and As (0.061 microg g(-1)), although these were well below the levels associated with clinical poisoning.

  3. Arsenic (As), antimony (Sb), and lead (Pb) availability from Au-mine Technosols: a case study of transfer to natural vegetation cover in temperate climates.

    PubMed

    Wanat, Nastasia; Joussein, Emmanuel; Soubrand, Marilyne; Lenain, Jean-François

    2014-08-01

    Soils from old Au-mine tailings (La Petite Faye, France) were investigated in relation to the natural vegetation cover to evaluate the risk of metals and metalloids (Pb, As, Sb) mobilizing and their potential transfer to native plants (Graminea, Betula pendula, Pteridium aquilinum, Equisetum telmateia). The soils are classified as Technosols with high contamination levels of As, Pb, and Sb. The single selective extractions tested to evaluate available fraction (CaCl2, acetic acid, A-Rhizo, and DTPA) showed low labile fractions (<5 % of bulk soil contents), but still significant levels were observed (up to 342.6 and 391.9 mg/kg for As and Pb, respectively) due to the high contamination levels of soils. Even at high soil contaminations (considered as phytotoxic levels for plants), translocation factors for native plants studied are very low resulting in low concentrations of As, Sb, and Pb in their aerial part tissues. This study demonstrates the important role of (1) native plant cover in terms of "stabilization" of these contaminants, and (2) the poor effectiveness of extraction procedures used for this type of soil assemblages, i.e., rich in specific mineral phases.

  4. "Zahraa", a Unani multicomponent herbal tea widely consumed in Syria: components of drug mixtures and alleged medicinal properties.

    PubMed

    Carmona, M D; Llorach, R; Obon, C; Rivera, D

    2005-12-01

    In Unani system of medicine, drugs consist of complex formulae with more than three components, for which, literature analysing these mixtures as they are sold in the market is scarce. In this paper, the main botanical components of the herbal tea known as "Zahraa" in Damascus, which contains between 6 and 14 species components is elucidated: Alcea damascena (Mout.) Mout. (Malvaceae), Aloysia triphylla (L'Herit.) Britt. (Malvaceae), Astragalus cf. amalecitanus Boiss., Cercis siliquastrum L. subsp. hebecarpa (Bornm.) Yalt. and subsp. siliquastrum. (Leguminosae), Colutea cilicica Boiss. et Bal. in Boiss. (Leguminosae), Crataegus aronia (L.) Bosc. ex DC. (Rosaceae), Cytisopsis pseudocytisus (Boiss.) Fertig. (Leguminosae), Eleagnus angustifolia L. (Eleagnaceae), Equisetum telmateia Ehrh. (Equisetaceae), Helichrysum stoechas (L.) Moench. subsp. barrelieri (Ten.) Nyman. (Compositae), Matricaria recutita L. (Compositae), Mentha longifolia L. subsp. noeana (Boiss. ex. Briq.) Briq. (Labiatae), Mentha spicata L. subsp. condensata (Briq.) Greuter and Burdet (Labiatae), Micromeria myrtifolia Boiss. and Hohen. in Boiss. (Labiatae), Paronychia argentea Lam. (Caryophyllaceae), Phlomis syriaca Boiss. (Labiatae), Rosa damascena Mill. (Rosaceae), Salvia fruticosa Mill. (Labiatae), Sambucus nigra L. (Caprifoliaceae), Spartium junceum L. (Leguminosae), Zea mays L. (Gramineae).

  5. Genetic Divergence of an Avian Endemic on the Californian Channel Islands

    PubMed Central

    Wilson, Amy G.; Chan, Yvonne; Taylor, Sabrina S.; Arcese, Peter

    2015-01-01

    The Californian Channel Islands are near–shore islands with high levels of endemism, but extensive habitat loss has contributed to the decline or extinction of several endemic taxa. A key parameter for understanding patterns of endemism and demography in island populations is the magnitude of inter–island dispersal. This paper estimates the extent of migration and genetic differentiation in three extant and two extinct populations of Channel Island song sparrows (Melospiza melodia graminea). Inter–island differentiation was substantial (G''ST: 0.14–0.37), with San Miguel Island having the highest genetic divergence and lowest migration rates. Santa Rosa and Santa Cruz Island populations were less diverged with higher migration rates. Genetic signals of past population declines were detected in all of the extant populations. The Channel Island populations were significantly diverged from mainland populations of M. m. heermanni (G''ST: 0.30–0.64). Ten mtDNA haplotypes were recovered across the extant and extinct Channel Island population samples. Two of the ten haplotypes were shared between the Northern and Southern Channel Islands, with one of these haplotypes being detected on the Californian mainland. Our results suggest that there is little contemporary migration between islands, consistent with early explanations of avian biogeography in the Channel Islands, and that song sparrow populations on the northern Channel Islands are demographically independent. PMID:26308717

  6. Examining the competitive advantage of Diuraphis noxia (Hemiptera: Aphididae) biotype 2 over biotype 1.

    PubMed

    Merrill, Scott C; Randolph, Terri L; Peairs, Frank B; Michels, G J; Walker, C B

    2014-08-01

    The Russian wheat aphid, Diuraphis noxia (Kurdjumov) is a serious pest of small grains, such as wheat and barley. High population growth rates and a broad gramineae host range have allowed this aphid to successfully establish and become pestiferous across much of North America since its invasion in the mid-1980s. Resistant wheat cultivars were developed and provided control ofD. noxia until 2003, when a new biotype (designated RWA2, as contrasted with the original biotype's designation, RWA1) emerged and rapidly spread through dryland winter wheat-growing regions. RWA2 displaced RWA1 more quickly than expected, based on RWA2's advantage in RWA1-resistant wheat cultivars. Previous research suggested that RWA2 may out-compete RWA1 in cooler temperatures. Thus, we sought to determine if RWA2 had a competitive advantage over RWA1 during the overwintering period. We placed a known distribution of RWA1 and RWA2 aphids in the field for the winter at three sites across a latitudinal gradient (from northern Colorado to Texas) to test for a competitive advantage between these biotypes. We found overwhelming support for an overwintering competitive advantage by RWA2 over RWA1, with evidence suggesting a > 10-fold advantage even at our Texas site (i.e., the site with the mildest winter). This substantial overwintering advantage helps explain the quick dispersion and displacement of RWA1 by RWA2.

  7. Late Pleistocene Vertebrates and Other Fossils from Epiguruk, Northwestern Alaska

    NASA Astrophysics Data System (ADS)

    Hamilton, Thomas D.; Ashley, Gall M.; Reed, Katherine M.; Schweger, Charles E.

    1993-05-01

    Sediments exposed at Epiguruk, a large cutbank on the Kobuk River about 170 km inland from Kotzebue Sound, record multiple episodes of glacial-age alluviation followed by interstadial downcutting and formation of paleosols. Vertebrate remains from Epiguruk include mammoth, bison, caribou, an equid, a canid, arctic ground squirrel, lemmings, and voles. Radiocarbon ages of bone validated by concordant ages of peat and wood span the interval between about 37,000 and 14,000 yr B.P. The late Pleistocene pollen record is dominated by Cyperaceae, with Artemisia, Salix, Betula, and Gramineae also generally abundant. The fossil record from Epiguruk indicates that the Kobuk River valley supported tundra vegetation with abundant riparian willows during middle and late Wisconsin time. Large herbivores were present during the height of late Wisconsin glaciation as well as during its waning stage and the preceding interstadial interval. The Kobuk River valley would have been a favorable refugium for plants, animals, and possibly humans throughout the last glaciation.

  8. Mitogen-activated protein kinase 4-like carrying an MEY motif instead of a TXY motif is involved in ozone tolerance and regulation of stomatal closure in tobacco

    PubMed Central

    Yanagawa, Yuki; Yoda, Hiroshi; Osaki, Kohei; Amano, Yuta; Aono, Mitsuko; Seo, Shigemi; Kuchitsu, Kazuyuki; Mitsuhara, Ichiro

    2016-01-01

    The mitogen-activated protein kinases (MAPKs/MPKs) are important factors in the regulation of signal transduction in response to biotic and abiotic stresses. Previously, we characterized a MAPK from tobacco, Nicotiana tabacum MPK4 (NtMPK4). Here, we found a highly homologous gene, NtMPK4-like (NtMPK4L), in tobacco as well as other species in Solanaceae and Gramineae. Deduced amino acid sequences of their translation products carried MEY motifs instead of conserved TXY motifs of the MAPK family. We isolated the full length NtMPK4L gene and examined the physiological functions of NtMPK4L. We revealed that NtMPK4L was activated by wounding, like NtMPK4. However, a constitutively active salicylic acid-induced protein kinase kinase (SIPKKEE), which phosphorylates NtMPK4, did not phosphorylate NtMPK4L. Moreover, a tyrosine residue in the MEY motif was not involved in NtMPK4L activation. We also found that NtMPK4L-silenced plants showed rapid transpiration caused by remarkably open stomata. In addition, NtMPK4L-silenced plants completely lost the ability to close stomata upon ozone treatment and were highly sensitive to ozone, suggesting that this atypical MAPK plays a role in ozone tolerance through stomatal regulation. PMID:27126796

  9. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water

    PubMed Central

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-01-01

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant’s ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters. PMID:26703632

  10. Response of aboveground biomass and diversity to nitrogen addition – a five-year experiment in semi-arid grassland of Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    He, Kejian; Qi, Yu; Huang, Yongmei; Chen, Huiying; Sheng, Zhilu; Xu, Xia; Duan, Lei

    2016-08-01

    Understanding the response of the plant community to increasing nitrogen (N) deposition is helpful for improving pasture management in semi-arid areas. We implemented a 5-year N addition experiment in a Stipa krylovii steppe of Inner Mongolia, northern China. The aboveground biomass (AGB) and species richness were measured annually. Along with the N addition levels, the species richness declined significantly, and the species composition changed noticeably. However, the total AGB did not exhibit a noticeable increase. We found that compensatory effects of the AGB occurred not only between the grasses and the forbs but also among Gramineae species. The plant responses to N addition, from the community to species level, lessened in dry years compared to wet or normal years. The N addition intensified the reduction of community productivity in dry years. Our study indicated that the compensatory effects of the AGB among the species sustained the stability of grassland productivity. However, biodiversity loss resulting from increasing N deposition might lead the semi-arid grassland ecosystem to be unsustainable, especially in dry years.

  11. Response of AM fungi spore population to elevated temperature and nitrogen addition and their influence on the plant community composition and productivity

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Yang, Xue; Guo, Rui; Guo, Jixun

    2016-04-01

    To examine the influence of elevated temperature and nitrogen (N) addition on species composition and development of arbuscular mycorrhizal fungi (AMF) and the effect of AMF on plant community structure and aboveground productivity, we conducted a 5-year field experiment in a temperate meadow in northeast China and a subsequent greenhouse experiment. In the field experiment, N addition reduced spore population diversity and richness of AMF and suppressed the spore density and the hyphal length density (HLD). Elevated temperature decreased spore density and diameter and increased the HLD, but did not affect AMF spore population composition. In the greenhouse experiment, AMF altered plant community composition and increased total aboveground biomass in both elevated temperature and N addition treatments; additionally, AMF also increased the relative abundance and aboveground biomass of the grasses Leymus chinensis (Poaceae) and Setaria viridis (Gramineae) and significantly reduced the relative abundance and aboveground biomass of the Suaeda corniculata (Chenopodiaceae). Although elevated temperature and N addition can affect species composition or suppress the development of AMF, AMF are likely to play a vital role in increasing plant diversity and productivity. Notably, AMF might reduce the threat of climate change induced degradation of temperate meadow ecosystems.

  12. LcSAIN1, a novel salt-induced gene from sheepgrass, confers salt stress tolerance in transgenic Arabidopsis and rice.

    PubMed

    Li, Xiaoxia; Hou, Shenglin; Gao, Qiong; Zhao, Pincang; Chen, Shuangyan; Qi, Dongmei; Lee, Byung-Hyun; Cheng, Liqin; Liu, Gongshe

    2013-07-01

    Previously, we identified >1,500 genes that were induced by high salt stress in sheepgrass (Leymus chinensis, Gramineae: Triticeae) when comparing the changes in their transcription levels in response to high salt stress by next-generation sequencing. Among the identified genes, a gene of unknown function (designated as Leymus chinensis salt-induced 1, LcSAIN1) showed a high sequence identity to its homologs from wheat, Hordeum vulgare and Oryza sativa, but LcSAIN1 and its homologs produce hypothetical proteins with no conserved functional domains. Transcription of the LcSAIN1 gene was up-regulated by various stresses. The overexpression of LcSAIN1 in Arabidopsis and rice increased the greening rate of cotyledons, the fresh weight, root elongation, plant height and the plant survival rate when compared with control plants and conferred a tolerance against salt stress. Subcellular localization analysis indicated that LcSAIN1 is localized predominantly in the nucleus. Our results show that the LcSAIN1 gene might play an important positive modulation role in increasing the expression of transcription factors (MYB2 and DREB2A) and functional genes (P5CS and RAB18) in transgenic plants under salt stress and that it augments stress tolerance through the accumulation of compatible solutes (proline and soluble sugar) and the alleviation of changes in reactive oxygen species. The LcSAIN1 gene could be a potential resource for engineering salinity tolerance in important crop species.

  13. Sasa quelpaertensis phenylpropanoid derivative suppresses lipopolysaccharide-induced nitric oxide synthase and cyclo-oxygenase-2 expressions in RAW 264.7 cells.

    PubMed

    Moon, Ji-Young; Yang, Eun-Jin; Kim, Sang Suk; Kang, Ji-Yong; Kim, Gi-Ok; Lee, Nam Ho; Hyun, Chang-Gu

    2011-01-01

    3-O-p-Coumaroyl-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-O-β-D-gulcopyranosylpropanol (ESQ10) is a naturally occurring phenylpropanoid derivative isolated from Sasa quelpaertensis (Gramineae). In the present study, we discovered that ESQ10 inhibits nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. ESQ10 attenuated LPS-induced synthesis of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in parallel and inhibited LPS-induced interleukin-6 production, as determined by an enzyme-linked immunosorbent assay in the macrophages. The mechanism of the antiinflammatory action of ESQ10, i.e., suppression of nuclear factor (NF)-κB and mitogen-activated protein kinase activation, has been documented. However, ESQ10 could not influence LPS-mediated IκB-α degradation and extracellular signal-regulated kinase/c-Jun amino-terminal kinase phosphorylation at concentrations of up to 373 µM. To test the potential application of ESQ10 as a topical material, we also conducted a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on human HaCaT keratinocytes as well as human dermal fibroblast cells. In this assay, ESQ10 did not induce cytotoxicity. Taken together, the results suggest that ESQ10 may be considered an antiinflammatory candidate for treating inflammatory and skin diseases.

  14. Investigations of the Host Range of the Corn Cyst Nematode, Heterodera zeae, from Maryland

    PubMed Central

    Ringer, Chloe E.; Sardanelli, Sandra; Krusberg, Lorin R.

    1987-01-01

    The host range of the corn cyst nematode, Heterodera zeae, recently detected in Maryland, was investigated. A total of 269 plant entries, representing 68 families, 172 genera, and 204 species, was inoculated with cysts or a mixture of eggs and second-stage juveniles of H. zeae. The host range of the Maryland population of H. zeae was limited to plants of the Gramineae and included 11 tribes, 33 genera, 42 species, and 77 entries. All 22 corn (Zea mays) cultivars tested were hosts. Other economic hosts included certain cultivars of barley (Hordeum vulgare), oat (Arena sativa), rice (Oryza sativa), sorghum (Sorghum bicolor), sugar cane (Saccharum interspecific hybrid), and wheat (Triticum aestivum). Fall panicum (Panicum dichotomiflorum), a weed species common to cultivated fields in Maryland, was also a host for H. zeae. Other hosts included meadow foxtail (Alopecurus pratensis), Calamagrostis eipgeios, Job's tears (Coix Lachryma-Jobi), green sprangletop (Leptochloa dubia), witchgrass (Panicum capillare), broomcorn (Panicum miliaceum), fountain grass (Pennisetum rueppeli), reed canary grass (Phalaris arundinacea), common reed (Phragmites australis), eastern gamagrass (Tripsacum dactyloides), corn (Zea mays), and teosinte (Zea mexicana). PMID:19290286

  15. Atmospheric pollen count in Monterrey, Mexico.

    PubMed

    González-Díaz, Sandra N; Rodríguez-Ortiz, Pablo G; Arias-Cruz, Alfredo; Macías-Weinmann, Alejandra; Cid-Guerrero, Dagoberto; Sedo-Mejia, Giovanni A

    2010-01-01

    There are few reports of pollen count and identification in Mexico; therefore, it is important to generate more information on the subject. This study was designed to describe the prevalence of pollen in the city of Monterrey, Mexico, during the year 2004. Atmospheric pollen was collected with a Hirst air sampler, with an airflow of 10 L/minute during 2004. Pollen was identified with light microscopy; the average monthly pollen count as well as total was calculated from January 2004 to January 2005. The months with the highest concentration of pollen were February and March (289 and 142 grains/m(3) per day, respectively), and July and November had the lowest concentration (20 and 11 grains/m(3) per day, respectively). Most of the pollen recollected corresponded to tree pollen (72%). Fraxinus spp had the highest concentration during the year (19 grains/m(3) per day; 27.5% of the total concentration of pollen). Tree pollen predominated from January through March; with Fraxinus spp, Morus spp, Celtis spp, Cupressus spp, and Pinus spp as the most important. Weed pollen predominated in May, June, and December and the most frequently identified, were Amaranthaceae/Chenopodiaceae, Ambrosia spp, and Parietaria spp. The highest concentration of grass pollen was reported during the months of May, June, September, October, and December with Gramineae/Poaceae predominating. Tree pollen was the most abundant during the year, with the ash tree having the highest concentration. Weed and grass pollen were perennial with peaks during the year.

  16. Late Pleistocene Vertebrates and Other Fossils from Epiguruk, Northwestern Alaska

    USGS Publications Warehouse

    Hamilton, T.D.; Ashley, G.M.; Reed, K.M.; Schweger, C.E.

    1993-01-01

    Sediments exposed at Epiguruk, a large cutbank on the Kobuk River about 170 km inland from Kotzebue Sound, record multiple episodes of glacial-age alluviation followed by interstadial downcutting and formation of paleosols. Vertebrate remains from Epiguruk include mammoth, bison, caribou, an equid, a canid, arctic ground squirrel, lemmings, and voles. Radiocarbon ages of bone validated by concordant ages of peat and wood span the interval between about 37,000 and 14,000 yr B.P. The late Pleistocene pollen record is dominated by Cyperaceae, with Artemisia, Salix, Betula, and Gramineae also generally abundant. The fossil record from Epiguruk indicates that the Kobuk River valley supported tundra vegetation with abundant riparian willows during middle and late Wisconsin time. Large herbivores were present during the height of late Wisconsin glaciation as well as during its waning stage and the preceding interstadial interval. The Kobuk River valley would have been a favorable refugium for plants, animals, and possibly humans throughout the last glaciation.

  17. [Role of man in the history of vegetation of the Ellero valley (maritime Alps, Italy)].

    PubMed

    Ortu, Elena; David, Fernand; Caramiello, Rosanna

    2003-07-01

    The pollen analysis of a sediment core from a peat bog (Rifugio Mondovi) at the mountain belt (1760 m) in the Ellero Valley (Italian Maritime Alps) shows the postglacial vegetation history. The sequence starts at 12,000 BP during a peak of pine pollen; this first phase shows a low representation of birch and the presence of Tilia. Younger Dryas is characterised by increasing percentages of Artemisia, showing the presence of deciduous Quercus, fir and beech. Elm appears at the beginning of the Holocene during the second pine peak (9800 BP). A 3000-year hiatus is present. Sedimentation resumes at 6000 BP in a Rhododendron fir-wood. The present timberline at 1500 m, at the limit of the beech wood, is a result of the decline of the fir-wood at 2600 BP, which allowed an expansion of beech. During this period, there was a continual increase in Gramineae and deciduous oak and the first occurrences of evergreen oak are observed. The development of larch occurs at 1800 BP, together with walnut, chestnut, cereals and vine.

  18. [Spatial and temporal dynamics of the weed community in the Zoysia matrella lawn].

    PubMed

    Liu, Jia-Qi; Li, You-Han; Zeng, Ying; Xie, Xin-Ming

    2014-02-01

    The heterogeneity of species composition is one of the main attributes in weed community dynamics. Based on species frequency and power law, this paper studied the variations of weed community species composition and spatial heterogeneity in a Zoysia matrella lawn in Guangzhou at different time. The results showed that there were 43 weed species belonging to 19 families in the Z. matrella lawn from 2007 to 2009, in which Gramineae, Compositae, Cyperaceae and Rubiaceae had a comparative advantage. Perennial weeds accounted for the largest proportion of weeds and increased gradually in the three years. Weed communities distributed in higher heterogeneity than in a random model. Dominant weeds varied with season and displayed regularity in the order of 'dicotyledon-monocotyledon-dicotyledon weeds' and 'perennial-annual-perennial weeds'. The spatial heterogeneity of weed community in Z. matrella lawn was higher in summer than in winter. The diversity and evenness of weed community were higher in summer and autumn than in winter and spring. The number of weed species with high heterogeneity in summer was higher than in the other seasons. The spatial heterogeneity and diversity of weed community had no significant change in the three years, while the evenness of weed community had the tendency to decline gradually.

  19. [Phylogenetic diversity of airborne microbes in Qingdao downtown in autumn].

    PubMed

    Wang, Lin; Song, Zhi-wen; Xu, Ai-ling; Wu, Deng-deng; Xia, Yan

    2015-04-01

    To determine the community structure of airborne microbes in Qingdao downtown in autumn, the airborne bacteria and fungi were collected by the KC-6120 air sampler and analyzed using the 16S/18S rDNA gene clone library method. Phylogenetic analysis of airborne bacteria showed that they belonged to six major phylogenetic groups: Proteobacteria (78. 8%), Firmicutes (14.6%), Actinobacteria (4.0%), Planctomycetes (1.3%), Cyanobacteria (0.7%), and Deinococcus-Thermus (0.7%). The dominant genera of airborne bacteria included Acinetobacter (39.7%), Staphylococcus (11.3%), Sphingomonas (8.6%), Paracoccus (6.0%) and Massilia (5.3%). The main types of airborne fungi were Ascomycota (97.5%) and Basidiomycota (2.5%). Dominant genera of airborne fungi included Pyrenophora (76.5%), Xylaria (13.6%) and Exophiala (2.5%). The pathogens or conditioned pathogens, such as Acinetobacter, Staphylococcus, or Sphingomonas were detected in the airborne bacteria, whereas certain kinds of fungi, such as P. graminea, X. hypoxylon and Zasmidium angulare that could cause a variety of crop diseases were also detected.

  20. Studies in neotropical paleobotany. XIV. A palynoflora from the middle Eocene Saramaguacan formation of Cuba

    USGS Publications Warehouse

    Graham, A.; Cozadd, D.; Areces-Mallea, A.; Frederiksen, N.O.

    2000-01-01

    An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacan Formation, Camaguey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleo-climate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacan flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America.

  1. Studies in Neotropical paleobotany. XIV. A palynoflora from the Middle Eocene Saramaguacan Formation of Cuba.

    PubMed

    Graham, A; Cozadd, D; Areces-Mallea, A; Frederiksen, N O

    2000-10-01

    An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacán Formation, Camagüey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleoclimate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacán flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America.

  2. Betaine synthesis in chenopods: localization in chloroplasts

    SciTech Connect

    Hanson, A.D.; May A.M.; Grumet, R.; Bode, J.; Jamieson, G.C.; Rhodes, D.

    1985-06-01

    Plants from several families (Chenopodiaceae, Gramineae, Compositae) accumulate betaine (glycine betaine) in response to salt or water stress via the pathway: choline betainal (betaine aldehyde) betaine. Betaine accumulation is probably a metabolic adaptation to stress. Intact protoplasts from leaves of spinach (Spinacia oleracea) oxidized ( UC)choline to betainal and betaine, as did protoplast lysates. Upon differential centrifugation, the ( UC)choline-oxidizing activity of lysates sedimented with chloroplasts. Chloroplasts purified from protoplast lysates by a Percoll cushion procedure retained strong ( UC)choline-oxidizing activity, although the proportion of the intermediate, ( UC)betainal, in the reaction products was usually higher than for protoplasts. Isolated chloroplasts also readily oxidized ( UC)betainal to betaine. Light increased the oxidation of both ( UC)choline and ( UC)betainal by isolated chloroplasts. Similar results were obtained with another chenopod (Beta vulgaris) but not with pea (Pisum sativum), a species that accumulates no betaine. The chloroplast site for betaine synthesis in chenopods contrasts with the mitochondrial site in mammals.

  3. The Relationship between Plants Used to Sustain Finches (Fringillidae) and Uses for Human Medicine in Southeast Spain.

    PubMed

    Belda, Antonio; Peiró, Victoriano; Seva, Eduardo

    2012-01-01

    We analyzed plants that are traditionally used by wild bird hunters and breeders to capture and promote captive breeding of Fringillidae (finches or songbirds) in the province of Alicante, Spain. The majority of plants used in songbird breeding have medicinal properties in traditional human medicine (48 different uses); thus, another main goal was to show their relationships with human medical uses. We compiled a list of 97 plant species from 31 botanical families that are used to attract finches and identified 11 different use categories for these plants in finch keeping. The most common uses were for trapping birds and as a source of food for birds in captivity. Cannabis sativa has the greatest cultural importance index (CI = 1.158), and Phalaris canariensis (annual canary grass or alpist) was the most common species used to attract Fringillidae and was used by all informants (n = 158). Most of the 97 species are wild plants and mainly belong to the families Compositae, Gramineae, Cruciferae, and Rosaceae and also have medicinal properties for humans. In the study area, the intensification of agriculture and abandonment of traditional management practices have caused the population of many songbirds to decline, as well as the loss of popular ethnographic knowledge.

  4. [Effect of preparations exhibiting cytokinin-like activity on the specific density of leaf in grasses].

    PubMed

    Cherniad'ev, I I

    2002-01-01

    The effects of synthetic preparations exhibiting cytokinin-like activity (6-benzylaminopurine, Thidiazuron, and kartolin-2) on the specific leaf area (SLA) were studied in plants of the family Gramineae (wheat, Triticum aestivum L.; meadow fescue, Festuca pratensis Huds.; and reed fescue, F. arindinacea Schreb.). At the early stages of ontogeny (until the leaf area reached 50-60% of the maximum value), treatment of plants of the three species with cytokinin-like preparations caused an increase in SLA. The SLA value in these plants was correlated with the rate of photosynthetic assimilation of carbon dioxide and activities of carbon metabolism enzymes: ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39), NAD-malate dehydrogenase (EC 1.1.1.37), and NADP-glyceraldehydrophosphate dehydrogenase complex, which includes phosphoglycerate kinase (EC 2.7.2.3) and glyceraldehydrophosphate dehydrogenase (EC 1.2.1.13). However, there was no correlation of SLA with the activity of phospho(enol)pyruvate carboxylase (EC 4.1.1.31), an anaplerotic carboxylation enzyme of grasses. SLA is suggested to reflect the state and activity of the photosynthetic apparatus and can be recommended as a characteristic of photosynthesis variability (e.g., caused by cytokinin-like preparations).

  5. [Allergy, pollen and the environment].

    PubMed

    Terán, Luis Manuel; Haselbarth-López, Michelle Marie Margarete; Quiroz-García, David Leonor

    2009-01-01

    Allergic respiratory diseases such asthma and allergic rhinitis are a health problem throughout the world. In Mexico City, pollens are an important cause of allergic respiratory disease. Both, the geographic location- and the vegetation surrounding this City favor the distribution of pollens leading to respiratory disease in susceptible patients. Aerobiological studies have shown that during the mild dry winter there is a large amount of pollens in the environment with tree pollens being the most abundant of all. The most frequent tree pollens found in Mexico City include Fraxinus, Cupressaseae, Alnus, Liquidambar, Callistemon, Pinus, and Casuarina. In contrast, grass- and weed pollens predominate during the summer (rainy season) including Compositae, Cheno-Am, Ambrosia and Gramineae. An additional health problem in Mexico City is the air pollution that exerts a direct effect on individuals. This in turn increases pollen allergenicity by disrupting them leading to the release of their particles which then penetrate the human airways causing disease. Thus, the polluted environment along with global warming which is also known to increase pollen quantities by inducing longer pollen seasons may represent a health risk to Mexico City inhabitants.

  6. Analogous reserve distribution and tissue characteristics in quinoa and grass seeds suggest convergent evolution

    PubMed Central

    Burrieza, Hernán P.; López-Fernández, María P.; Maldonado, Sara

    2014-01-01

    Quinoa seeds are highly nutritious due to the quality of their proteins and lipids and the wide range of minerals and vitamins they store. Three compartments can be distinguished within the mature seed: embryo, endosperm, and perisperm. The distribution of main storage reserves is clearly different in those areas: the embryo and endosperm store proteins, lipids, and minerals, and the perisperm stores starch. Tissues equivalent (but not homologous) to those found in grasses can be identified in quinoa, suggesting the effectiveness of this seed reserve distribution strategy; as in cells of grass starchy endosperm, the cells of the quinoa perisperm endoreduplicate, increase in size, synthesize starch, and die during development. In addition, both systems present an extra-embryonic tissue that stores proteins, lipids and minerals: in gramineae, the aleurone layer(s) of the endosperm; in quinoa, the micropylar endosperm; in both cases, the tissues are living. Moreover, the quinoa micropylar endosperm and the coleorhiza in grasses play similar roles, protecting the root in the quiescent seed and controlling dormancy during germination. This investigation is just the beginning of a broader and comparative study of the development of quinoa and grass seeds. Several questions arise from this study, such as: how are synthesis and activation of seed proteins and enzymes regulated during development and germination, what are the genes involved in these processes, and lastly, what is the genetic foundation justifying the analogy to grasses. PMID:25360139

  7. The Relationship between Plants Used to Sustain Finches (Fringillidae) and Uses for Human Medicine in Southeast Spain

    PubMed Central

    Belda, Antonio; Peiró, Victoriano; Seva, Eduardo

    2012-01-01

    We analyzed plants that are traditionally used by wild bird hunters and breeders to capture and promote captive breeding of Fringillidae (finches or songbirds) in the province of Alicante, Spain. The majority of plants used in songbird breeding have medicinal properties in traditional human medicine (48 different uses); thus, another main goal was to show their relationships with human medical uses. We compiled a list of 97 plant species from 31 botanical families that are used to attract finches and identified 11 different use categories for these plants in finch keeping. The most common uses were for trapping birds and as a source of food for birds in captivity. Cannabis sativa has the greatest cultural importance index (CI = 1.158), and Phalaris canariensis (annual canary grass or alpist) was the most common species used to attract Fringillidae and was used by all informants (n = 158). Most of the 97 species are wild plants and mainly belong to the families Compositae, Gramineae, Cruciferae, and Rosaceae and also have medicinal properties for humans. In the study area, the intensification of agriculture and abandonment of traditional management practices have caused the population of many songbirds to decline, as well as the loss of popular ethnographic knowledge. PMID:22611428

  8. Metal concentrations and mycorrhizal status of plants colonizing copper mine tailings: potential for revegetation.

    PubMed

    Chen, Baodong; Tang, Xiangyu; Zhu, Yongguan; Christie, Peter

    2005-05-01

    A field survey of metal concentrations and mycorrhizal status of plants growing on copper mine tailings was conducted in Anhui Province, China. Available phosphorus and organic matter in the tailings were very low. High concentrations of Pb, Zn, As and Cd as well as Cu were observed on some sites. The dominant plants growing on mine tailings belonged to the families Gramineae and Compositae, and the most widely distributed plant species were Imperata cylindrica, Cynodon dactylon and Paspalum distichum. Coreopsis drummondii also grew well on the arid sites but not on wet sites. Very low or zero arbuscular mycorrhizal (AM) fungal colonization was observed in most of the plants, but extensive mycorrhizal colonization was recorded in the roots of C. drummondii and C. dactylon. Metal concentrations in plant tissues indicated that I. cylindrica and P. distichum utilized avoidance mechanisms to survive at high metal concentrations. The investigation suggests that remediation and revegetation of heavy metal contaminated sites might be facilitated by selection of tolerant plant species. Isolation of tolerant AM fungi may also be warranted.

  9. Zero Tillage cotton systems and soil quality

    NASA Astrophysics Data System (ADS)

    Landers, J. N.; de Freitas, P. L.

    2012-04-01

    Monocropping in cotton production systems negates the benefits of zero tillage. With cotton in a 3-year rotation including other summer and cover crops, such as soybeans and intensive-rooting Brachiaria spp., research on sandy soils in Bahia improved soil fertility, structure and biological activity. Cotton is a deep tap-rooted crop, sensitive to physical and chemical impediments to root development; this has engendered a paradigm of heavy soil preparation operations to remove these. But, ZT can overcome such obstacles, allowing the cotton crop to benefit from cost reductions and a number of other benefits, especially erosion control.. Soil quality has three principal dimensions. Maximum yields only occur when soil fertility, structure and biological activity are in balance. Under Zero Tillage management of Brazilian soils, the processes of nutrient availability, nutrient cycling and efficiency result from increasing SOM and higher CEC. ZT system fertility is also strongly influenced by total annual aerial and root biomass generation; C:N ratios of the biomass, changes in aeration in residue breakdown processes (for roots, dependent on internal drainage), reduced fixation of Phosphorus fertilizers, the possibility of surface application of P and K, use of deep-rooted cover crops to re-cycle nutrients and deleterious effects of over-liming. Soil physical parameters undergo a transformation : greater water holding capacity, a small increase in bulk density (ameliorated by a reversal of soil aggregate breakdown inherent to conventional tillage by the binding action of root exudates and fungal hyphae), enhanced particle aggregate size protects SOM from oxidation; old root holes create semi-permanent macro-pores which facilitate rooting, aeration and rainfall infiltration.. Soil life of all types benefits from ZT management and contributes to soil fertility and structural improvements, plus enhancing certain biological controls of pathogenic organisms and allelopathic

  10. The next chapter of direct phytolith 14C dating: debunking the myth of occluded photosynthetic carbon exclusivity

    NASA Astrophysics Data System (ADS)

    Santos, G.; Harutyunyan, A.; Alexandre, A. E.; Reyerson, P. E.; Gallagher, K. L.; Isabelle, B. D.

    2014-12-01

    Radiocarbon dating of carbon (C) encapsulated in phytoliths (phytC) is currently used in many Earth Science disciplines for absolute chronologies and paleoclimatic reconstructions; however, the usefulness of phytC has been hampered by inadequate extraction methods[1] and uncertainties regarding its origin as purely photosynthetic [2,3,4]. An early investigation measuring isotopes from Gramineae spp. grown in free-air C enrichment experiments (FACE), showed that part of of its phytC is from a non-photosynthetic source, thus indicating a dual origin[5]. To demonstrate that non-photosynthetic sources within phytC could be from soil C stocks, we measured 14C-AMS phytC extracted from a set of Sorghum bicolor growing on known 14C and d13C bulk substrates and hydroponic solutions. The phytolith concentrates and a silica blank were extracted at UCI, CEREGE and Wisconsin using an improved protocol [1,2]. We also measured CO2 fluxes and isotopic signatures of microbial respiration, percentage of biomass and phytolith extracts produced, and isotopic signatures of the local air and bulk-plant during the growing season of 2012. This allowed comparison of the belowground substrate and nutrient C contributions to phytC 14C results. Meanwhile, NanoSIMS analyses of phytolith polished sections was used to locate phytC in the phytolith siliceous structure [6]. These results will be shown and discussed. [1] Corbineau et al. 2013 R. Paleobot. Palyn. 197: 179 [2] Santos et al. 2010 T. Radiocarbon 52:113 [3] Santos et al. 2012a Biogeosci. 9:1873 [4] Santos et al. 2012b Biogeosci. Discussion 9:C6114 [5] Reyerson et al. 2013 AGU Fall meeting 2013 (Abstract ID: 1803125). [6] Alexandre, et al., submitted.

  11. Proton magnetic resonance characterization of phoratoxins and homologous proteins related to crambin

    SciTech Connect

    Lecomte, J.T.J.; Kaplan, D.; Llinas, M.; Thunberg, E.; Samuelsson, G.

    1987-02-24

    The mistletoe protein toxins, phoratoxins A and B, viscotoxins A3 and B have been investigated by /sup 1/H NMR spectroscopy at 300 and 600 MHz. The five polypeptides define a set of closely related homologues, containing 46 amino acid residues each, in a structure constrained by three cystine bridges. Their methyl and aromatic spectra were analyzed and a number of signals identified and assigned via comparative criteria, two-dimensional chemical-shift correlated spectroscopy, acid-base titration, and proton Overhauser experiments in /sup 1/H/sub 2/O. The spectra indicate a compact globular conformation and a common folding pattern for the toxins. In particular, use was made of well-resolved aliphatic and aromatic resonances in order to compare the mistletoe proteins with the thionins, a set of homologous toxins from gramineae, and with crambin, a closely related polypeptide from a crucifer. The authors observe that while all the investigated proteins have very similar secondary and tertiary structures, they differ widely in their dynamic characteristics as probed by the amide NH /sup 1/H-/sup 2/H exchange kinetics in deuteriated solvents. The temperature dependence of the /sup 1/H NMR spectrum also indicates that the toxins are endowed with a thermally very stable native (ground-state) structure, with little evidence of large amplitude structural breathings up to approx.370 K, although irreversible chemical degradation (denaturation) becomes evident at temperatures greater than or equal to 350 K. It is concluded that the mistletoe toxins afford valuable rigid structures for NMR conformation studies.

  12. A Holocene vegetation record from the Mississippi River Valley, southeastern Missouri

    USGS Publications Warehouse

    King, J.E.; Allen, W.H.

    1977-01-01

    Pollen preserved in a peat deposit from a large swamp, the Old Field in the Mississippi River Valley near Advance, Missouri, records radiocarbon-dated vegetation changes between 9000 and about 3000 years ago. The principal feature of both the percentage and influx pollen diagrams is the replacement of arboreal pollen, primarily Quercus, Fraxinus, and Cephalanthus, with Gramineae and NAP between 8700 and 5000 years BP. This vegetation shift is interpreted as reflecting a decrease in the extent of the Old Field swamp and its associated bottomland forest species along with the expansion of a grass-dominated herb community, as a result of a reduction in available ground water. The desiccation of the swamp during this period indicates a reduction in precipitation within the ground-water source area and a shift to a drier climate in the southern Midwest. The pollen suggests that the lowest water levels and driest climate in southeastern Missouri lasted from 8700 to 6500 years BP, at which time there is a partial reappearance of swamp species. Relatively dry conditions, however, continued until at least 5000 years BP. Although pollen influx data are lacking from the upper part of the profile, the relative pollen frequencies suggest an increase in trees after 5000 BP. The replacement of the arboreal vegetation by grasses and herbs between 8700 and 5000 years BP reflects the period of maximum expansion of the Prairie Peninsula in southeastern Missouri. The Old Field swamp provides the first pollen evidence that the vegetational changes along the southern border of the Prairie Peninsula were chronologically similar to those on the northern and northeastern margins. ?? 1977.

  13. Soil properties and species composition under different grazing intensity in an alpine meadow on the eastern Tibetan Plateau, China.

    PubMed

    Yang, Zhen'an; Xiong, Wan; Xu, Yingyi; Jiang, Lin; Zhu, Erxiong; Zhan, Wei; He, Yixin; Zhu, Dan; Zhu, Qiuan; Peng, Changhui; Chen, Huai

    2016-12-01

    As the main form of land use and human disturbance of grassland, livestock grazing has great influences on the soil resources and plant communities. This study observed the variation of soil properties and community characteristics of four treatments of different grazing intensity (no grazing, UG; light grazing, LG; moderate grazing, MG; and heavy grazing, HG) in an alpine meadow of Sichuan Province on the northeastern margin of the Tibetan Plateau. The results showed that grazing increased the pH, soil bulk density (BD), and contents of total carbon (TC) and total nitrogen (TN), and the BD increased while the others decreased with the grazing intensity. At the community level, with the increase of the grazing intensity, the vegetation coverage (R (2) = 0.61, P < 0.001), mean height of community (R (2) = 0.37, P < 0.001), aboveground biomass (R (2) = 0.54, P < 0.001), litter biomass (R (2) = 0.84, P < 0.001), and percentage of aboveground biomass of palatable grasses to total biomass (R (2) = 0.74, P < 0.001) significantly decreased, while the belowground biomass (R (2) = 0.72, P < 0.001) and the root/shoot (R/S) ratio (R (2) = 0.65, P < 0.001) increased. The species richness was the greatest at LG and the total biomass at UG. With grazing, the dominant species of the plant community shifted from palatable grasses (Gramineae and Cyperaceae) to unpalatable grasses (Compositae and Ranunculaceae). Based on the results, LG may be the optimal grassland management mode to be used in the long time in the alpine meadow of the Tibetan Plateau.

  14. A novel, in vivo, indoor method to preserve rice black-streaked dwarf virus in small brown planthopper using wheat seedling as a bridge host.

    PubMed

    Ren, Chunmei; Cheng, Zhaobang; Yang, Liu; Miao, Qian; Fan, Yongjian; Zhou, Yijun

    2014-11-01

    Rice black-streaked dwarf virus (RBSDV) naturally infects Gramineae plants through small brown planthopper (SBPH) as a vector. However, RBSDV cannot be transmitted to the SBPH offspring through transovarian transmission. Wheat plant, an important intermediate host in winter, is essential for the completion of the annual cycle of RBSDV in farm ecosystem. We developed a novel, in vivo, indoor method to preserve RBSDV in SBPH using wheat seedling as a bridge host. The temperature range of 23-27°C was initially selected to rear the insects and plants. Before initiating the scheme cycle, viruliferous SBPH was obtained by feeding the virus-free 1st to 2nd instar nymphs with RBSDV-infected rice plants. Four to six RBSDV-infected SBPH were placed per plant to inoculate wheat seedlings at two-to-four leaf stages. After 48 h of inoculation, the viruliferous SBPH were removed. Five mated, newly emerged virus-free SBPH females were then transferred onto each inoculated plant and allowed to lay eggs for 48 h. The newly hatched SBPH were raised on wheat seedlings until the 2nd instar nymph stage, and then transferred onto healthy rice seedlings for further development until 5th instar nymphs or adults. These newly obtained viruliferous SBPH can be used for inoculating new wheat seedlings in the succeeding maintenance cycles, or for further experiments. We discovered that the incubation period of RBSDV in wheat seedlings synchronized with the gestation period of SBPH eggs at four to six inoculated viruliferous SBPH per plant and lasted for approximately seven days. In addition, this period was optimal for enhancing the SBPH infection ratio because SBPH nymphs can only acquire the virus after they hatch. The RBSDV infection ratio of the SBPHs acquired through this method consistently exceeded 50%.

  15. Four QTLs determine crown rust (Puccinia coronata f. sp. lolii) resistance in a perennial ryegrass (Lolium perenne) population.

    PubMed

    Muylle, H; Baert, J; Van Bockstaele, E; Pertijs, J; Roldán-Ruiz, I

    2005-11-01

    Crown rust resistance is an important selection criterion in ryegrass breeding. The disease, caused by the biotrophic fungus Puccinia coronata, causes yield losses and reduced quality. In this study, we used linkage mapping and QTL analysis to unravel the genomic organization of crown rust resistance in a Lolium perenne population. The progeny of a pair cross between a susceptible and a resistant plant were analysed for crown rust resistance. A linkage map, consisting of 227 loci (AFLP, SSR, RFLP and STS) and spanning 744 cM, was generated using the two-way pseudo-testcross approach from 252 individuals. QTL analysis revealed four genomic regions involved in crown rust resistance. Two QTLs were located on LG1 (LpPc4 and LpPc2) and two on LG2 (LpPc3 and LpPc1). They explain 12.5, 24.9, 5.5 and 2.6% of phenotypic variance, respectively. An STS marker, showing homology to R genes, maps in the proximity of LpPc2. Further research is, however, necessary to check the presence of functional R genes in this region. Synteny at the QTL level between homologous groups of chromosomes within the Gramineae was observed. LG1 and LG2 show homology with group A and B chromosomes of oat on which crown rust-resistance genes have been identified, and with the group 1 chromosomes of the Triticeae, on which leaf rust-resistance genes have been mapped. These results are of major importance for understanding the molecular background of crown rust resistance in ryegrasses. The identified markers linked to crown rust resistance have the potential for use in marker-assisted breeding.

  16. The spectrum of olive pollen allergens.

    PubMed

    Rodríguez, R; Villalba, M; Monsalve, R I; Batanero, E

    2001-07-01

    Olive pollen is one of the most important causes of seasonal respiratory allergy in Mediterranean countries, where this tree is intensely cultivated. Among the high number of protein allergens detected in this pollen, 8 - Ole e 1 to Ole e 8 - have been isolated and characterized. Ole e 1 is the most frequent sensitizing agent, affecting more than 70% of the patients suffering of olive pollinosis, although others, such as Ole e 4 and Ole e 7, have also been shown to be major allergens. In this context, the prevalence of many olive pollen allergens seems to be dependent on the geographical area where the sensitized patients live. Some of the olive allergens have been revealed as members of known protein families: profilin (Ole e 2), Ca(2+)-binding proteins (Ole e 3 and Ole e 8), superoxide dismutase (Ole e 5) and lipid transfer protein (Ole e 7). No biological function has been demonstrated for Ole e 1, whereas Ole e 4 and Ole e 6 are new proteins without homology to known sequences from databases. cDNAs encoding for Ole e 1, Ole e 3 and Ole e 8 have been overproduced in heterologous systems. The recombinant products were correctly folded and exhibited the functional activities of the natural allergens. In addition to the Oleaceae family, other species, such as Gramineae or Betulaceae, contain pollen allergens structurally or immunologically related to those of the olive tree. This fact allows to detect and evaluate antigenic cross-reactivities involving olive allergens. The aim of this research is the development of new diagnostic tools for olive pollinosis and new approaches to improve the classical immunotherapy.

  17. A major allergen from pollen defines a novel family of plant proteins and shows intra- and interspecies [correction of interspecie] cross-reactivity.

    PubMed

    Barral, Patricia; Batanero, Eva; Palomares, Oscar; Quiralte, Joaquín; Villalba, Mayte; Rodríguez, Rosalía

    2004-03-15

    Olive tree (Olea europaea) pollen is a main cause of allergy associated with extensive areas of Europe and North America. Ole e 10, a small (10.8 kDa) and acidic (pI 5.8) protein, has been identified as a major allergen from the olive pollen, isolated, and characterized. Circular dichroism analysis gave 17% alpha helix, 33% beta sheet, and 21% beta turn for its secondary structure. Based on amino acid sequences of tryptic peptides, the protein was cloned and sequenced. The allergen consists of a single polypeptide chain of 102 aa, with a signal peptide of 21 residues. Ole e 10 showed homology with the C-terminal domain of another olive allergen, Ole e 9 (1,3-beta-glucanase, 53% identity), with deduced sequences from Arabidopsis thaliana genes (42-46% identity) and with polypeptide segments (Cys boxes) of proteins involved in yeast development (Epd1/Gas-1p/Phr2 families; 42-43% similarity). Ole e 10 showed 55% prevalence for olive-allergic patients and exhibited an IgE response dependent on its conformation. Remarkable IgE cross-reactivity was detected with Ole e 9, but no correlation was observed between the individual IgE responses to both allergens. Ole e 10 shares IgE B cell epitopes with proteins from Oleaceae, Gramineae, Betulaceae, Chenopodiaceae, Cupressaceae, Ambrosia, and Parietaria pollens, latex, and vegetable foods, such as tomato, kiwi, potato, and peach. These data indicate that Ole e 10 is a new pan-allergenic plant protein that shows notable intra- and interspecie IgE cross-reactivity and is a powerful candidate to be involved in pollen-latex-fruit syndrome.

  18. Holocene vegetational history of the Kootenai River Valley, Montana

    NASA Astrophysics Data System (ADS)

    Mack, Richard N.; Rutter, N. W.; Valastro, S.

    1983-09-01

    Pollen records in the Kootenai and Fisher River drainages in western Montana reveal a fivezone sequence of Holocene vegetation change. Deposition of Glacier Peak Ash-Layer G (ca. 10,540 ± 660 yr B.P.) in the lowermost sediments (clay intermixed with pebbles) at Tepee Lake gives a minimum date for the initiation of sedimentation. Initial vegetation on the newly deglaciated terrain was dominated by Pinus (probably white bark pine) with small amounts of Gramineae, Picea and Abies, reflecting a relatively cool, moist macroclimate. Two vegetation units appear to contribute to Pollen Zone II (ca. 11,000-7100 yr B.P.): arboreal communities with pines, along with Pseudotsuga or Larix, or both, and treeless vegetation dominated by Artemisia. Pollen Zone II represents an overall warmer macroclimate than occurred upon ice withdrawal. After ca. 7100 yr B.P. (Pollen Zone III) diploxylon pines became a major pollen contributor near both Tepee Lake and McKillop Creek Pond, indicating an expansion of xerophytic forest ( P. contorta and P. ponderosa) along with an increase in the prominence of Pseudotsuga menziesii or Larix occidentalis, or both. Artemisia briefly expanded coverage near Tepee Lake concomitant with the Mazama ashfall ca. 6700 yr B.P. A short-term climatic trend with more available water began after ca. 4000 yr B.P. as Abies (probably A. grandis) along with Picea engelmannii became a more regular component of the forest surrounding both sites. Emergence of the modern macroclimate is indicated primarily with the first regular appearance of Tsuga heterophylla in the pollen record by ca. 2700 yr B.P., synchronous with the development of western hemlock forest within the same latitudes in northern Idaho and northeastern Washington.

  19. Chromatographic analysis of wheatgrass extracts

    PubMed Central

    Khan, Masood Shah; Parveen, Rabea; Mishra, Kshipra; Tulsawani, Rajkumar; Ahmad, Sayeed

    2015-01-01

    Aim: Wheatgrass (WG) is the shoot of Triticum aestivum Linn. belongs to the family Gramineae, and possess high chlorophyll content and essential vitamins, minerals, vital enzymes, amino acids, dietary fibers etc., It has been shown to possess anti-cancer, anti-ulcer, antioxidant, and anti-arthritic activity due to the presence of biologically active compounds, and minerals. Therefore, in the present study, high-performance thin layer chromatography (HPTLC), and high-performance liquid chromatography (HPLC) methods for qualitative and quantitative analysis have been proposed, which will help in quality evaluation of wheat grass extract. Materials and Methods: Samples for analysis were prepared in methanol and water simply by sonication. These were applied on pre-coated silica plate and chromatograms were developed using toluene: Ethyl acetate: Formic acid. HPLC analysis was done on Waters HPLC system using water, methanol, and acetonitrile as mobile phase. Merck C18 column has been used. Results: HPTLC finger printing of alcoholic extracts of WG was carried out and found 10–11 spots at different wavelengths 254, 366, and 435 nm. HPLC fingerprinting produced 22 peaks at 256 nm. Quantitative HPTLC analysis was done to determine the gallic acid content, and was found to be 0.077% w/w in aqueous extract. By HPLC, the content of gallic acid and rutin was found to be 0.07%, and 0.04% w/w in aqueous extract of WG. Conclusion: The developed HPLC and HPTLC fingerprinting method can be used for the quality control, and standardization of WG and its extracts used as nutritional supplement. PMID:26681880

  20. Susceptibility of the bruchid Callosobruchus maculatus (Coleoptera: Bruchidae) and its parasitoid Dinarmus basalis (Hymenoptera: Pteromalidae) to three essential oils.

    PubMed

    Ketoh, Guillaume K; Glitho, Adole I; Huignard, Jacques

    2002-02-01

    The bruchid Callosobruchus maculatus (F.) causes major losses during the storage of seeds of Vigna unguiculata (Walp.) in West Africa. An endemic parasitoid, the pteromalid Dinarmus basalis (Rond.) reduces the increase in bruchid populations in stores and could be used for biological control. African farmers often introduce essential oils into granaries at harvest time. In Togo, essential oils were extracted from two Gramineae, Cymbopogon nardus (L.) and Cymbopogon schoenanthus (L.) and from a Lamiaceae, Ocimum basilicum (L.). The major components of these essential oils were citronellal in C. nardus, carene-2 and piperitone in C. schoenanthus and estragol in O. basilicum. Cymbopogon schoenanthus was the most toxic oil for C. maculatus adults. D. basalis adults were more susceptible to the three essential oils than the adults of their hosts C. maculatus. In the presence of cowpea seeds, the LC50s of the three essential oils were lower than in their absence, suggesting that the seeds may absorb a part of the volatiles. High doses of three essential oils slightly affected the survival of the fourth instar or the pupae of C. maculatus. This high survival was due to protection of larvae from volatiles by the surrounding seeds. The D. basalis were more affected by the oil volatiles than their hosts. Sub-lethal doses of essential oils reduced the duration of the adult life of both insect species and fecundity of the females. The differences in sensitivity of the host and its parasitoid could influence their population dynamics. The introduction of the essential oils into storage systems potentially could reduce density of parasitoid populations and increase seed losses.

  1. HvHMA2, a P(1B)-ATPase from barley, is highly conserved among cereals and functions in Zn and Cd transport.

    PubMed

    Mills, Rebecca F; Peaston, Kerry A; Runions, John; Williams, Lorraine E

    2012-01-01

    Manipulation of crops to improve their nutritional value (biofortification) and optimisation of plants for removal of toxic metals from contaminated soils (phytoremediation) are major goals. Identification of membrane transporters with roles in zinc and cadmium transport would be useful for both aspects. The P(1B)-ATPases play important roles in heavy metal allocation and detoxification in Arabidopsis and it is now important to elucidate their roles in monocots. We identified nine P(1B)-ATPases in barley and this study focuses on the functional characterization of HvHMA2, providing evidence for its role in heavy metal transport. HvHMA2 was cloned using information from EST analysis and 5' RACE. It possesses the conserved aspartate that is phosphorylated during the reaction cycle of P-type pumps and has motifs and key residues characteristic of P(1B)-ATPases, falling into the P(1B-2) subclass. Homologous sequences occur in three major sub-families of the Poaceae (Gramineae). Heterologous expression in Saccharomyces cerevisiae demonstrates that HvHMA2 functions as a Zn and Cd pump. Mutagenesis studies show that proposed cation coordination sites of the P(1B-2) pumps are crucial for the metal responses conferred by HvHMA2 in yeast. HvHMA2 expression suppresses the Zn-deficient phenotype of the Arabidopsis hma2hma4 mutant indicating that HvHMA2 functions as a Zn pump in planta and could play a role in root to shoot Zn transport. When expressed in Arabidopsis, HvHMA2 localises predominantly to the plasma membrane.

  2. Selection of Candidate Reference Genes for Gene Expression Analysis in Kentucky Bluegrass (Poa pratensis L.) under Abiotic Stress.

    PubMed

    Niu, Kuiju; Shi, Yi; Ma, Huiling

    2017-01-01

    Kentucky bluegrass (Poa pratensis L.) belong to Gramineae and is widely used in lawns, golf courses, landscapes, and sport fields as a prominent cool-season grass. Gene expression patterns during different stages of plant development can provide clues toward the understanding of its biological functions. The selection and validation of reference genes are the first steps in any real-time quantitative PCR gene expression study. Therefore, suitable reference genes are necessary for obtaining reliable results in real-time quantitative PCR analyses of Kentucky bluegrass. In the present study, 9 candidate reference genes were chosen, and their expression stability in the leaves and roots of Kentucky bluegrass under different stresses (drought, salt, heat, and cold) were evaluated using the GeNorm, NormFinder, BestKeeper, and RefFinder programs. The results showed that the expression stability of the candidate reference genes was dependent on the experimental conditions. The combination of SAM with GAPDH was the most stable in leaves under salt stress and cold stress, while TUB combined with ACT or GAPDH was stable in roots under salt or cold stress, respectively. ACT and SAM maintained stable expression in drought-treated leaves, and GAPDH combined with ACT was stable in drought-treated roots. SAM and TUB exhibited stable expression in heat-treated leaves. ACT and RPL were stable in heat-treated roots. In addition, the expression patterns of PpFEH in response to drought and cold stress were used to confirm the reliability of the selected reference genes, indicating that the use of an inappropriate reference gene as the internal control will cause erroneous results. This work is the first study on the expression stability of reference genes in Kentucky bluegrass and will be particularly useful in the selection of stress-tolerance genes and the identification of the molecular mechanisms conferring stress tolerance in this species.

  3. Changing of dominant atmospheric circulation since LGM recorded by a lake core in the central Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Wang, J.; Lu, X.; Daut, G.; Kasper, T.; Haberzettl, T.; Schwalb, A.; Maeusbacher, R.

    2013-12-01

    The mechanism of climate changes and some abrupt events on the Tibetan Plateau since LGM exists many uncertainties. Further understanding is possibly provided by a continue lake core records in the Nam Co (4718 asl, 2015 km2) on the central Tibetan Plateau. The 11m long core collected in 90m deep water area has a well age-depth distribution according to 32 14C dating data. 24-19 kaBP, higher Pediastrum suggested a shallow water condition. 19-16.5kaBP, decreased Pediastrum and Cyperaceae suggested water depth increasing and wetland reducing. Pinus, Picea and Abies were over than 30% during 24-16.5 kaBP, implying a different climate condition than it at present. 16.5-14.2 kaBP, humidity was enhanced according to Cyperaceae, Gramineae, Artemisia and Chenopodiacen. Pinus, Picea and Abies were less than 10%, suggesting climate shifted in lake area. 14.2-13.2 kaBP, Fe/Mn, Ca and Sr/Ba indicated water depth increase while total pollen concentration (TPC) and TOC (endogenesis source) reflected temperature rising. 13.2-11.5 kaBP, cold-dry climate was reflected by lake volume changing based upon Fe/Mn, Ca, Sr/Ba and Pediastrum, and the decreasing of TOC and TCP. 11.5-8.5 kaBP, a good water and heat condition was indicated by pollen assemblages and geochemistry, and the best period was within 10.2-9.3 kaBP. 8.5-5.8 kaBP, the best water-heat condition gradually weakened according to decreased TCP but stable TOC. After 5.8 kaBP, climate tended to be dry. In general, there were not only existed several climatic change events in the Nam Co lake area, but also occurred climatic type shifting since LGM.

  4. A comparison of stable caesium uptake by six grass species of contrasting growth strategy.

    PubMed

    Willey, N J; Martin, M H

    1997-01-01

    Six plant species in the family Gramineae were used to investigate the relationship between Cs uptake, nutrient regime and plant growth strategy sensu Grime (1979: Plant Growth Strategies and Vegetation Processes, John Wiley). The roots of 66 day old Elymus repens (L.) Gould., Bromus sterilis L., Agrostis stolonifera L., Anthoxanthum odoratum L., Festuca ovina L. and Nardus stricta L. plants grown in acid-washed sand at high and low nutrient levels were exposed to a 96 h pulse of stable Cs at 0.05 mM, 0.15 mM, 0.3 mM, 1.0 mM and 3.0 mM concentrations. Different nutrient regimes induced large differences in dry wt in E. repens, B. sterilis and A. stolonifera plants but only small differences in N. stricta and F. ovina plants. At high nutrient concentrations, A. stolonifera, A. odoratum, F. ovina and N. stricta shoots showed significantly greater increases in internal Cs concentration with rising external Cs concentrations than did E. repens and B. sterilis shoots. The relationship between increases in shoot and external Cs concentrations was statistically indistinguishable between species in plants grown at the low nutrient concentration. These patterns of Cs uptake ensured that with long-term high K concentrations the more competitive plants (E. repens and B. sterilis) accumulated higher concentrations of Cs from low external concentrations than did non-competitive plants or competitive plants grown at low nutrient levels. It is suggested that the relationship between plant growth strategy sensu Grime (1979) and Cs accumulation patterns may help to explain the different concentrations to which species accumulate radiocaesium from the soil.

  5. Succession of Bacterial Community Structure and Diversity in Soil along a Chronosequence of Reclamation and Re-Vegetation on Coal Mine Spoils in China

    PubMed Central

    Li, Yuanyuan; Wen, Hongyu; Chen, Longqian; Yin, Tingting

    2014-01-01

    The growing concern about the effectiveness of reclamation strategies has motivated the evaluation of soil properties following reclamation. Recovery of belowground microbial community is important for reclamation success, however, the response of soil bacterial communities to reclamation has not been well understood. In this study, PCR-based 454 pyrosequencing was applied to compare bacterial communities in undisturbed soils with those in reclaimed soils using chronosequences ranging in time following reclamation from 1 to 20 year. Bacteria from the Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria, Planctomycetes and Bacteroidetes were abundant in all soils, while the composition of predominant phyla differed greatly across all sites. Long-term reclamation strongly affected microbial community structure and diversity. Initial effects of reclamation resulted in significant declines in bacterial diversity indices in younger reclaimed sites (1, 8-year-old) compared to the undisturbed site. However, bacterial diversity indices tended to be higher in older reclaimed sites (15, 20-year-old) as recovery time increased, and were more similar to predisturbance levels nearly 20 years after reclamation. Bacterial communities are highly responsive to soil physicochemical properties (pH, soil organic matter, Total N and P), in terms of both their diversity and community composition. Our results suggest that the response of soil microorganisms to reclamation is likely governed by soil characteristics and, indirectly, by the effects of vegetation restoration. Mixture sowing of gramineae and leguminosae herbage largely promoted soil geochemical conditions and bacterial diversity that recovered to those of undisturbed soil, representing an adequate solution for soil remediation and sustainable utilization for agriculture. These results confirm the positive impacts of reclamation and vegetation restoration on soil microbial diversity and suggest that the most important

  6. Selection of Candidate Reference Genes for Gene Expression Analysis in Kentucky Bluegrass (Poa pratensis L.) under Abiotic Stress

    PubMed Central

    Niu, Kuiju; Shi, Yi; Ma, Huiling

    2017-01-01

    Kentucky bluegrass (Poa pratensis L.) belong to Gramineae and is widely used in lawns, golf courses, landscapes, and sport fields as a prominent cool-season grass. Gene expression patterns during different stages of plant development can provide clues toward the understanding of its biological functions. The selection and validation of reference genes are the first steps in any real-time quantitative PCR gene expression study. Therefore, suitable reference genes are necessary for obtaining reliable results in real-time quantitative PCR analyses of Kentucky bluegrass. In the present study, 9 candidate reference genes were chosen, and their expression stability in the leaves and roots of Kentucky bluegrass under different stresses (drought, salt, heat, and cold) were evaluated using the GeNorm, NormFinder, BestKeeper, and RefFinder programs. The results showed that the expression stability of the candidate reference genes was dependent on the experimental conditions. The combination of SAM with GAPDH was the most stable in leaves under salt stress and cold stress, while TUB combined with ACT or GAPDH was stable in roots under salt or cold stress, respectively. ACT and SAM maintained stable expression in drought-treated leaves, and GAPDH combined with ACT was stable in drought-treated roots. SAM and TUB exhibited stable expression in heat-treated leaves. ACT and RPL were stable in heat-treated roots. In addition, the expression patterns of PpFEH in response to drought and cold stress were used to confirm the reliability of the selected reference genes, indicating that the use of an inappropriate reference gene as the internal control will cause erroneous results. This work is the first study on the expression stability of reference genes in Kentucky bluegrass and will be particularly useful in the selection of stress-tolerance genes and the identification of the molecular mechanisms conferring stress tolerance in this species. PMID:28261247

  7. Post-zygotic Reproductive Isolation Between Sympatric Taxa in the Chamaecrista desvauxii Complex (Leguminosae–Caesalpinioideae)

    PubMed Central

    Costa, Cristiana Barros Nascimento; Lambert, Sabrina Mota; Borba, Eduardo Leite; de Queiroz, Luciano Paganucci

    2007-01-01

    Background and Aims Differences in the mating systems and the mechanisms of reproductive isolation between Chamaecrista desvauxii var. graminea and C. desvauxii var. latistipula were examined in the Chapada Diamantina, Brazil. These taxa occur sympatrically, and their populations demonstrate marked morphological differences. The objective of the present work was to determine if reproductive isolation mechanisms exist between these two populations of C. desvauxii, and to determine the influence of these putative mechanisms on their genetic differentiation. Methods Field observations were made of floral biology, phenology and floral visitation, and experiments on intra- and interpopulation pollination and germination rates of the resultant seeds were performed. A genetic examination of the populations was undertaken using four allozyme loci. Key Results The varieties examined demonstrated overlapping of flowering periods during the months of June to September. The main pollinator for both varieties was the bee Bombus brevivillus. Both varieties are self-compatible, and a large number of fruits are formed in cross-pollinations with high seed germination rates. Inter-taxa pollinations result in high levels of fruit production, but no seeds are formed. Two of the four loci examined were diagnostic for the varieties, and exclusive high-frequency alleles were encountered at the other loci, leading to a high genetic distance between the two populations (0·495). Conclusions Pre-zygotic barriers were not found between the two varieties, and these remain isolated due to post-zygotic events. The two varieties demonstrate marked differences in their morphology, floral biology, phenology and genetic make-up, all of which indicate that they should be treated as two distinct species. A complete revision involving the other varieties of the C. desvauxii complex will be necessary in order to define these two taxa formally. PMID:17331960

  8. The response of southern California ecosystems to Younger Dryas-like rapid climate change: Comparison of glacial terminations 1 and 5.

    NASA Astrophysics Data System (ADS)

    Heusser, L. E.; Hendy, I. L.

    2015-12-01

    The Younger Dryas is a well-known rapid climatic cooling that interrupted the Marine Isotope Stage (MIS) 1-2 deglacial warming of Termination 1. This cool event has been associated with ice sheet readvance, meridional overturning, circulation changes, and southward movement of the Intertropical Convergence Zone. In Southern California, the Younger Dryas has been associated with cooler SST, low marine productivity, a well-ventilated oxygen minimum zone, and a wetter climate. Similar rapid cooling events have been found at other terminations including Termination 5 at the MIS 11-12 deglaciation (~425 Ka) identified by ice rafting events in the North Atlantic. Here we present new pollen census data from a unique suite of cores taken from the sub-oxic sediments of Santa Barbara Basin (MV0508-15JC, MV0805-20JC, MV0508-33JC, 29JC and 21JC). These short cores, collected on a truncated anticline within SBB, provide the opportunity to examine the response of southern California terrestrial and marine ecosystems to rapid climate change during the MIS 11-12 deglaciation (Termination 5), which is identified by a bioturbated interval within a sequence of laminated sediments. During Termination 1, changes in Southern California precipitation are reflected in pollen- based reconstructions Southern California vegetation. The high precipitation of glacial montane-coniferous assemblages of pine (Pinus) and Juniper (Juniperus/Calocedrus) transitions into interglacial drought, as expresssed by arid oak (Quercus)/chaparral vegetation. The Younger Dryas interrupts the transition as a high-amplitude pulse in pine associated with increased Gramineae (grass). Termination 5 differs, as the high precipitation of glacial montane-coniferous assemblages do not transition into arid oak/chaparral vegetation. However, a Younger Dryas-like rapid climate event was associated with increased pine and grass.

  9. Integrated karyotyping of sorghum by in situ hybridization of landed BACs.

    PubMed

    Kim, Jeong-Soon; Childs, Kevin L; Islam-Faridi, M Nurul; Menz, Monica A; Klein, Robert R; Klein, Patricia E; Price, H James; Mullet, John E; Stelly, David M

    2002-04-01

    The reliability of genome analysis and proficiency of genetic manipulation are increased by assignment of linkage groups to specific chromosomes, placement of centromeres, and orientation with respect to telomeres. We have endeavored to establish means to enable these steps in sorghum (Sorghum bicolor (L.) Moench), the genome of which contains ca. 780 Mbp spread across n = 10 chromosomes. Our approach relies on fluorescence in situ hybridization (FISH) and integrated structural genomic resources, including large-insert genomic clones in bacterial artificial chromosome (BAC) libraries. To develop robust FISH probes, we selected sorghum BACs by association with molecular markers that map near the ends of linkage groups, in regions inferred to be high in recombination. Overall, we selected 22 BACs that encompass the 10 linkage groups. As a prelude to development of a multiprobe FISH cocktail, we evaluated BAC-derived probes individually and in small groups. Biotin- and digoxygenin-labeled probes were made directly from the BAC clones and hybridized in situ to chromosomes without using suppressive unlabelled C0t-1 DNA. Based on FISH-signal strength and the relative degree of background signal, we judged 19 BAC-derived probes to be satisfactory. Based on their relative position, and collective association with all 10 linkage groups, we chose 17 of the 19 BACs to develop a 17-locus probe cocktail for dual-color detection. FISH of the cocktail allowed simultaneous identification of all 10 chromosomes. The results indicate that linkage and physical maps of sorghum allow facile selection of BAC clones according to position and FISH-signal quality. This capability will enable development of a high-quality molecular cytogenetic map and an integrated genomics system for sorghum, without need of chromosome flow sorting or microdissection. Moreover, transgeneric FISH experiments suggest that the sorghum system might be applicable to other Gramineae.

  10. Ethnobotanic importance of plants used in pigeon-breeding in Eastern Spain

    PubMed Central

    2013-01-01

    Background The importance that birds of the Columbidae family have had throughout history is visible on the Mediterranean coast. Pigeon fancying is the art of breeding and training carrier pigeons and currently, several breeds exist. The sport of racing pigeons consists in covering a distance at maximum possible speed. However, pigeon breeding has another modality called “sport pigeon”, where several males follow a female. This study focusses on ethnobotanical knowledge of native and exotic plant species that are used for diet, breeding, stimulation, healing illnesses and staining the plumage of pigeons bred in captivity. Methods Using semi-structured interviews, we gathered information about the different plant species traditionally used for pigeon-breeding in the region of Valencia. Background material on remedies for bird illnesses was gathered from folk botanical references, local books and journals.The plant species were collected in the study area, then identified in the laboratory using dichotomous keys and vouchered in the ABH (Herbarium of Alicante University). We used Excel ® 2003 to perform a simple statistical analysis of the data collected. Results We collected 56 species of plants (and one variety) that included 29 botanical families. The total number of species was made up of 35 cultivated and 21 wild plants. The most common were Gramineae (14 species), Leguminosae (6 species), and Compositae (4 species). Conclusions Pigeon breeding is an immensely popular activity in Eastern Spain, and ethnobiological knowledge about breeding pigeons and caring for them is considerable. The names and traditional uses of plants depend on their geographical location, vernacular names serve as an intangible heritage. Feeding, environmental features, and genetic makeup of individuals are relevant aspects in the maintenance of avian health. PMID:23688245

  11. Cyanobacteria associated with Anopheles albimanus (Diptera: Culicidae) larval habitats in southern Mexico.

    PubMed

    Vázquez-Martínez, M Guadalupe; Rodríguez, Mario H; Arredondo-Jiménez, Juan I; Méndez-Sanchez, José D; Bond-Compeán, J Guillermo; Cold-Morgan, Michelle

    2002-11-01

    Cyanobacteria associated with Anopheles albimanus Wiedemann larval habitats from southern Chiapas, Mexico, were isolated and identified from water samples and larval midguts using selective medium BG-11. Larval breeding sites were classified according to their hydrology and dominant vegetation. Cyanobacteria isolated in water samples were recorded and analyzed according to hydrological and vegetation habitat breeding types, and mosquito larval abundance. In total, 19 cyanobacteria species were isolated from water samples. Overall, the most frequently isolated cyanobacterial taxa were Phormidium sp., Oscillatoria sp., Aphanocapsa cf. littoralis, Lyngbya lutea, P. animalis, and Anabaena cf. spiroides. Cyanobacteria were especially abundant in estuaries, irrigation canals, river margins and mangrove lagoons, and more cyanobacteria were isolated from Brachiaria mutica, Ceratophyllum demersum, and Hymenachne amplexicaulis habitats. Cyanobacteria were found in habitats with low to high An. albimanus larval abundance, but Aphanocapsa cf. littoralis was associated with habitats of low larval abundance. No correlation was found between water chemistry parameters and the presence of cyanobacteria, however, water temperature (29.2-29.4 degrees C) and phosphate concentration (79.8-136.5 ppb) were associated with medium and high mosquito larvae abundance. In An. albimanus larval midguts, only six species of cyanobacteria were isolated, the majority being from the most abundant cyanobacteria in water samples.

  12. Vegetation-derived cues for the selection of oviposition substrates by Anopheles albimanus under laboratory conditions.

    PubMed

    Torres-Estrada, José Luis; Meza-Alvarez, R Amanda; Cibrián-Tovar, Juan; Rodríguez-López, Mario H; Arredondo-Jiménez, Juan I; Cruz-López, Leopoldo; Rojas-Leon, Julio C

    2005-12-01

    Oviposition response of gravid Anopheles albimanus Wiedemman (Diptera: Culicidae) females to water containing Brachiaria mutica, Cynodon dactylon, Jouvea straminea, Fimbristylis spadicea, and Ceratophyllum demersum was investigated. Gravid An. albimanus females deposited similar egg numbers in cups containing natural plants in water from natural breeding sites and in cups containing natural plants in distilled water. Gravid mosquitoes deposited significantly more eggs in cups containing natural plants in water from natural breeding sites than in cups containing artificial plants in water from the corresponding natural breeding sites. These results were confirmed in experiments conducted in a wind tunnel, indicating that female response is mediated by chemical cues from plants. Bioassays with organic extracts of all 5 plant species indicated that these extracts at 100%, 10%, and 1% concentrations had an oviposition repellent effect, while attractiveness was observed at 0.1%, 0.01%, and 0.001%. Gas chromatography and mass spectrometry analysis of the organic extracts found in all 5 plants showed a mixture of terpenoid and alcohol compounds, among them: guaiacol, phenol, isoeugenol, longifolene, caryophyllene, phenyl ethyl alcohol, and p-cresol. These results suggest that middle-range volatiles from plants may function as chemical cues for the female's oviposition response in this mosquito species.

  13. Change in growth performance of crossbred (Ankole × Jersey) dairy heifers fed on forage grass diets supplemented with commercial concentrates.

    PubMed

    Mutimura, Mupenzi; Ebong, Cyprian; Rao, Idupulapati Madhusudana; Nsahlai, Ignatius Verla

    2016-04-01

    Rearing heifers for dairy cow replacement is a challenge in smallholder dairy farms in the tropics due to feed shortage. The objective of this study was to evaluate Brachiaria hybrid cultivar Mulato II as a forage resource for improving growth performance of dairy heifers under cut-and-carry feeding system in Rwanda. Sixteen crossbred (Ankole × Jersey) heifers (mean weight 203 ± 35 kg) were randomly allocated to two dietary treatments viz: Mulato II with 2 kg/day of commercial concentrates (MCC) and Napier grass (Pennisetum purpureum) with the same supplement (NCC), for a period of 12 weeks. Mineral lick and water were provided ad libitum. Daily feed intake and fortnightly live weight were measured. Average daily gains and feed conversion ratio (FCR) were calculated. Results showed that absolute daily dry matter intake (g DMI/day) and relative intake (g/kg of metabolic body weight--BW(0.75)) were higher in heifers fed on MCC than in heifers fed on NCC (P < 0.001). FCR was lower (P < 0.001) in MCC than NCC diets. Final body weight (FBW) and body weight gain (BWG) did not differ between the two groups of heifers (P > 0.05). Average daily weight gain (ADWG) also not differed significantly (P > 0.05). Based on numerical body weight changes and nutritive values, Mulato II showed potential to be integrated into local cut-and-carry feeding systems for better heifer rearing to facilitate dairy cow replacement.

  14. Sound absorption coefficient in situ: an alternative for estimating soil loss factors.

    PubMed

    Freire, Rosane; Meletti de Abreu, Marco Henrique; Okada, Rafael Yuri; Soares, Paulo Fernando; GranhenTavares, Célia Regina

    2015-01-01

    The relationship between the sound absorption coefficient and factors of the Universal Soil Loss Equation (USLE) was determined in a section of the Maringá Stream basin, Paraná State, by using erosion plots. In the field, four erosion plots were built on a reduced scale, with dimensions of 2.0×12.5m. With respect to plot coverage, one was kept with bare soil and the others contained forage grass (Brachiaria), corn and wheat crops, respectively. Planting was performed without any type of conservation practice in an area with a 9% slope. A sedimentation tank was placed at the end of each plot to collect the material transported. For the acoustic system, pink noise was used in the measurement of the proposed monitoring, for collecting information on incident and reflected sound pressure levels. In general, obtained values of soil loss confirmed that 94.3% of material exported to the basin water came from the bare soil plot, 2.8% from the corn plot, 1.8% from the wheat plot, and 1.1% from the forage grass plot. With respect to the acoustic monitoring, results indicated that at 16kHz erosion plot coverage type had a significant influence on the sound absorption coefficient. High correlation coefficients were found in estimations of the A and C factors of the USLE, confirming that the acoustic technique is feasible for the determination of soil loss directly in the field.

  15. Testing the Amazon savannization hypothesis: fire effects on invasion of a neotropical forest by native cerrado and exotic pasture grasses.

    PubMed

    Silvério, Divino V; Brando, Paulo M; Balch, Jennifer K; Putz, Francis E; Nepstad, Daniel C; Oliveira-Santos, Claudinei; Bustamante, Mercedes M C

    2013-06-05

    Changes in climate and land use that interact synergistically to increase fire frequencies and intensities in tropical regions are predicted to drive forests to new grass-dominated stable states. To reveal the mechanisms for such a transition, we established 50 ha plots in a transitional forest in the southwestern Brazilian Amazon to different fire treatments (unburned, burned annually (B1yr) or at 3-year intervals (B3yr)). Over an 8-year period since the commencement of these treatments, we documented: (i) the annual rate of pasture and native grass invasion in response to increasing fire frequency; (ii) the establishment of Brachiaria decumbens (an African C4 grass) as a function of decreasing canopy cover and (iii) the effects of grass fine fuel on fire intensity. Grasses invaded approximately 200 m from the edge into the interiors of burned plots (B1yr: 4.31 ha; B3yr: 4.96 ha) but invaded less than 10 m into the unburned plot (0.33 ha). The probability of B. decumbens establishment increased with seed availability and decreased with leaf area index. Fine fuel loads along the forest edge were more than three times higher in grass-dominated areas, which resulted in especially intense fires. Our results indicate that synergies between fires and invasive C4 grasses jeopardize the future of tropical forests.

  16. [Soil microbial activity variation after land use changes in savannah, Llanos Orientales, Venezuela].

    PubMed

    Gómez, Yrma; Paolini, Jorge

    2011-03-01

    In West plains of Venezuela, the traditional land use of the Trachypogon savannah, has been the extensive grazing. The pressure over these savannahs to obtain a major animal productivity has stimulated the introduction of exotic forage plants, such as Brachiaria brizantha and Andropogon gayanus. In spite that great savannah extensions have been subject to this land use change, information about the effect that pastures and grazing activity have on microbial activity in these soils is scarce. So the objective of this study was to determine the impact that the extensive grazing and cover substitution have on microbial activity. The soil sampling was carried out during the dry and rainy seasons. The employed parameters to determine changes in soil microbial activity were the substrate induced respiration (SIR), basal respiration (BR), the dehydrogenase activity (DHS), the fluorescein diacetate hydrolysis (FDA) and the arginene ammonification (AA). The similarity of the structural soil characteristics studied allows us to infer, that the differences in the microbiological parameters are determined by climatic conditions and soil management. The results show that there is a low microbial activity in these soils. The rainy season caused an increase in all the microbiological parameters determined. B. brizantha made a greater contribution to soil carbon and promoted a greater heterotrophic activity. The extensive grazing and the low stocking rate in the West plain savannas did not affect the microbial activity in these soils.

  17. Testing the Amazon savannization hypothesis: fire effects on invasion of a neotropical forest by native cerrado and exotic pasture grasses

    PubMed Central

    Silvério, Divino V.; Brando, Paulo M.; Balch, Jennifer K.; Putz, Francis E.; Nepstad, Daniel C.; Oliveira-Santos, Claudinei; Bustamante, Mercedes M. C.

    2013-01-01

    Changes in climate and land use that interact synergistically to increase fire frequencies and intensities in tropical regions are predicted to drive forests to new grass-dominated stable states. To reveal the mechanisms for such a transition, we established 50 ha plots in a transitional forest in the southwestern Brazilian Amazon to different fire treatments (unburned, burned annually (B1yr) or at 3-year intervals (B3yr)). Over an 8-year period since the commencement of these treatments, we documented: (i) the annual rate of pasture and native grass invasion in response to increasing fire frequency; (ii) the establishment of Brachiaria decumbens (an African C4 grass) as a function of decreasing canopy cover and (iii) the effects of grass fine fuel on fire intensity. Grasses invaded approximately 200 m from the edge into the interiors of burned plots (B1yr: 4.31 ha; B3yr: 4.96 ha) but invaded less than 10 m into the unburned plot (0.33 ha). The probability of B. decumbens establishment increased with seed availability and decreased with leaf area index. Fine fuel loads along the forest edge were more than three times higher in grass-dominated areas, which resulted in especially intense fires. Our results indicate that synergies between fires and invasive C4 grasses jeopardize the future of tropical forests. PMID:23610179

  18. Selecting plants and nitrogen rates to vegetate crude-oil-contaminated soil.

    PubMed

    Kirkpatrick, W D; White, P M; Wolf, D C; Thoma, G J; Reynolds, C M

    2006-01-01

    Phytoremediation can be effective for remediating contaminated soils in situ and generally requires the addition of nitrogen (N) to increase plant growth. Our research objectives were to evaluate seedling emergence and survival of plant species and to determine the effects of N additions on plant growth in crude-oil-contaminated soil. From a preliminary survival study, three warm-season grasses--pearlmillet (Pennisetum glaucum [L.] R. Br.), sudangrass (Sorghum sudanense [Piper] Stapf [Piper]), and browntop millet (Brachiaria ramosa L.)--and one warm-season legume--jointvetch (Aeschynomene americana L.)--were chosen to determine the influence of the N application rate on plant growth in soil contaminated with weathered crude oil. Nitrogen was added based on total petroleum hydrocarbon-C:added N ratios (TPH-C:TN) ranging from 44:1 to 11:1. Plant species were grown for 7 wk. Root and shoot biomass were determined and root length and surface area were analyzed. Pearlmillet and sudangrass had higher shoot and root biomass when grown at a TPH-C:TN (inorganic) ratio of 11:1 and pearlmillet had higher root length and surface area when grown at 11:1 compared with the other species. By selecting appropriate plant species and determining optimum N application rates, increased plant root growth and an extended rhizosphere influence should lead to enhanced phytoremediation of crude-oil-contaminated soil.

  19. Occurrence and diversity of arbuscular mycorrhizal fungi in trap cultures from soils under different land use systems in the Amazon, Brazil

    PubMed Central

    Leal, Patrícia Lopes; Stürmer, Sidney Luiz; Siqueira, José Oswaldo

    2009-01-01

    The aim of this work was to evaluate the occurrence of arbuscular mycorrhizal fungi (AMF) species diversity in soil samples from the Amazon region under distinct land use systems (Forest, Old Secondary Forest, Young Secondary Forest, Agroforestry systems, Crops and Pasture) using two distinct trap cultures. Traps established using Sorghum sudanense and Vigna unguiculata (at Universidade Regional de Blumenau -FURB) and Brachiaria decumbens and Neonotonia wightii (at Universidade Federal de Lavras - UFLA) were grown for 150 days in greenhouse conditions, when spore density and species identification were evaluated. A great variation on species richness was detected in several samples, regardless of the land use systems from where samples were obtained. A total number of 24 AMF species were recovered using both methods of trap cultures, with FURB′s traps yielding higher number of species. Acaulospora delicata, A. foveata, Entrophospora colombiana and two undescribed Glomus species were the most abundant and frequent species recovered from the traps. Number of species decreased in each genus according to this order: Acaulospora, Glomus, Entrophospora, Gigaspora, Archaeospora, Scutellospora and Paraglomus. Spore numbers were higher in Young Secondary Forest and Pastures. Our study demonstrated that AMF have a widespread occurrence in all land use systems in Amazon and they sporulate more abundantly in trap cultures from land uses under interference than in the pristine Forest ecosystem. PMID:24031328

  20. Investigation of the water purification efficiency of flood irrigation system by using flora succession as an index.

    PubMed

    Yuan, Yu-Kang; Huang, Chih-Min

    2010-03-01

    A flood irrigation system was constructed to remove nutrient-based water pollutants through the various natural treatment mechanisms of plants and microorganisms. Species of plants were allowed to proliferate naturally within the system. The succession of flora was then utilized as an index to evaluate the water purification efficiency of the flood irrigation system. The natural growth of plants during the test period indicated what part of the irrigation system would recover most efficiently from nutrient-based contamination. From the first stage of observation (50 days) to the second stage (50 days), the average processing efficiencies of Nitrate Nitrogen (NO3(-)-N) and Ortho-phosphate (PO4(3-)) were improved 1.7% and 70.3%, respectively. After the 60th day, the Compositae family flourished in the system. At the same time, removal rate of Nitrate Nitrogen was increased dramatically which may be related to prevalence of the Compositae family. Trends indicate that the Ortho-phosphate concentration of the irrigated water was low, and Brachiaria mutica of Poaceae were dominant which may have lead to the phenomenon of phosphorus released in the flood irrigation system.

  1. Assessment and kinetics of soil phosphatase in Brazilian Savanna systems.

    PubMed

    Ferreira, Adão S; Espíndola, Suéllen P; Campos, Maria Rita C

    2016-05-31

    The activity and kinetics of soil phosphatases are important indicators to evaluate soil quality in specific sites such as the Cerrado (Brazilian Savanna). This study aimed to determine the activity and kinetic parameters of soil phosphatase in Cerrado systems. Soil phosphatase activity was assessed in samples of native Cerrado (NC), no-tillage (NT), conventional tillage (CT) and pasture with Brachiaria brizantha (PBb) and evaluated with acetate buffer (AB), tris-HCl buffer (TB), modified universal buffer (MUB) and low MUB. The Michaelis-Menten equation and Eadie-Hofstee model were applied to obtain the kinetic parameters of soil phosphatase using different concentrations of p-nitrophenol phosphate (p-NPP). MUB showed the lowest soil phosphatase activity in all soils whereas AB in NC and NT presented the highest. Low MUB decreased interferences in the assessment of soil phosphatase activity when compared to MUB, suggesting that organic acids interfere on the soil phosphatase activity. In NC and NT, soil phosphatase activity performed with TB was similar to AB and low MUB. Km values from the Michaels-Menten equation were higher in NC than in NT, which indicate a lower affinity of phosphatase activity for the substrate in NC. Vmax values were also higher in NC than in NT. The Eadie-Hofstee model suggests that NC had more phosphatase isoforms than NT. The study showed that buffer type is of fundamental importance when assessing soil phosphatase activity in Cerrado soils.

  2. Ticks (Acari: Ixodidae) associated with wildlife and vegetation of Haller park along the Kenyan coastline.

    PubMed

    Wanzala, W; Okanga, S

    2006-09-01

    This artcile describes the results obtained from a tick survey conducted in Haller park along the Kenyan coastline. The survey aimed at evaluating tick-host associations, assessing tick population density, and providing baseline information for planning future tick control and management in the park. Ticks (2,968) were collected by handpicking from eight species of wildlife and by dragging in 14 selected sites within the park. A considerable proportion of ticks were also collected from leaves, stems, and bark of most dominant trees, namely, Casuarina equisetifolia L. (Forst. and Forst.), Cocos nucifera L., Adansonia digitata L., Musa paradisiaca L., and Azadiracta indica Adr. Juss. Dragging was conducted in sites predominantly occupied by Cynodon dactylon L. (Pers.), Cenchrus ciliaris L., Stenotaphrum dimidiatum L. (Kuntze.) Brongn., and Brachiaria xantholeuca Hack. Ex Schinz Stapf. and Loudetia kagerensis K. Schum. Hutch. Eight tick species were identified, and the collection included Rhipicephalus pravus Dönitz 1910, Rhipicephalus pulchellus Gerstäcker 1873, Hyalomma marginatum rufipes Koch 1844, Amblyomma gemma Dönitz 1910, Amblyomma hebraeum Koch 1844, Amblyomma sparsum Neumann 1899, Amblyomma nuttalli Dönitz 1909, and Boophilus decoloratus Koch 1844. Given that the identified tick species are known to parasitize humans as well as livestock, there exist risks of emergence of zoonotic infections mediated by tick vectors. In the recreational environment of Haller park, where tick vectors share habitats with hosts, there is a need to develop sustainable and effective tick control and management strategies to minimize economic losses that tick infestation may cause.

  3. Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation.

    PubMed

    Lopes Leal, Patrícia; Varón-López, Maryeimy; Gonçalves de Oliveira Prado, Isabelle; Valentim Dos Santos, Jessé; Fonsêca Sousa Soares, Cláudio Roberto; Siqueira, José Oswaldo; de Souza Moreira, Fatima Maria

    Spore counts, species composition and richness of arbuscular mycorrhizal fungi, and soil glomalin contents were evaluated in a soil contaminated with Zn, Cu, Cd and Pb after rehabilitation by partial replacement of the contaminated soil with non-contaminated soil, and by Eucalyptus camaldulensis planting with and without Brachiaria decumbens sowing. These rehabilitation procedures were compared with soils from contaminated non-rehabilitated area and non-contaminated adjacent soils. Arbuscular mycorrhizal fungi communities attributes were assessed by direct field sampling, trap culture technique, and by glomalin contents estimate. Arbuscular mycorrhizal fungi was markedly favored by rehabilitation, and a total of 15 arbuscular mycorrhizal fungi morphotypes were detected in the studied area. Species from the Glomus and Acaulospora genera were the most common mycorrhizal fungi. Number of spores was increased by as much as 300-fold, and species richness almost doubled in areas rehabilitated by planting Eucalyptus in rows and sowing B. decumbens in inter-rows. Contents of heavy metals in the soil were negatively correlated with both species richness and glomalin contents. Introduction of B. decumbens together with Eucalyptus causes enrichment of arbuscular mycorrhizal fungi species and a more balanced community of arbuscular mycorrhizal fungi spores in contaminated soil.

  4. Soil biological attributes in arsenic-contaminated gold mining sites after revegetation.

    PubMed

    Dos Santos, Jessé Valentim; de Melo Rangel, Wesley; Azarias Guimarães, Amanda; Duque Jaramillo, Paula Marcela; Rufini, Márcia; Marra, Leandro Marciano; Varón López, Maryeimy; Pereira da Silva, Michele Aparecida; Fonsêca Sousa Soares, Cláudio Roberto; de Souza Moreira, Fatima Maria

    2013-12-01

    Recovery of arsenic contaminated areas is a challenge society faces throughout the world. Revegetation associated with microbial activity can play an essential role in this process. This work investigated biological attributes in a gold mining area with different arsenic contents at different sites under two types of extant revegetation associated with cover layers of the soil: BS, Brachiaria sp. and Stizolobium sp., and LEGS, Acacia crassicarpa, A. holosericea, A. mangium, Sesbania virgata, Albizia lebbeck and Pseudosamanea guachapele. References were also evaluated, comprising the following three sites: B1, weathered sulfide substrate without revegetation; BM, barren material after gold extraction and PRNH (private reserve of natural heritage), an uncontaminated forest site near the mining area. The organic and microbial biomass carbon contents and substrate-induced respiration rates for these sites from highest to lowest were: PRNH > LEGS > BS > B1 and BM. These attributes were negatively correlated with soluble and total arsenic concentration in the soil. The sites that have undergone revegetation (LEGS and BS) had higher densities of bacteria, fungi, phosphate solubilizers and ammonium oxidizers than the sites without vegetation. Principal component analysis showed that the LEGS site grouped with PRNH, indicating that the use of leguminous species associated with an uncontaminated soil cover layer contributed to the improvement of the biological attributes. With the exception of acid phosphatase, all the biological attributes were indicators of soil recovery, particularly the following: microbial carbon, substrate-induced respiration, density of culturable bacteria, fungi and actinobacteria, phosphate solubilizers and metabolic quotient.

  5. Bacterial rhizosphere and endosphere populations associated with grasses and trees to be used for phytoremediation of crude oil contaminated soil.

    PubMed

    Fatima, Kaneez; Afzal, Muhammad; Imran, Asma; Khan, Qaiser M

    2015-03-01

    Different grasses and trees were tested for their growth in a crude oil contaminated soil. Three grasses, Lolium perenne, Leptochloa fusca, Brachiaria mutica, and two trees, Lecucaena leucocephala and Acacia ampliceps, were selected to investigate the diversity of hydrocarbon-degrading rhizospheric and endophytic bacteria. We found a higher number of hydrocarbon degrading bacteria associated with grasses than trees and that the endophytic bacteria were taxonomically different from rhizosphere associated bacteria showing their spatial distribution with reference to plant compartment as well as genotype. The rhizospheric soil yielded 22 (59.45 %), root interior yielded 9 (24.32 %) and shoot interior yielded 6 (16.21 %) hydrocarbon-degrading bacteria. These bacteria possessed genes encoding alkane hydroxylase and showed multiple plant growth-promoting activities. Bacillus (48.64 %) and Acinetobacter (18.91 %) were dominant genera found in this study. At 2 % crude oil concentration, all bacterial isolates exhibited 25 %-78 % oil degradation and Acinetobacter sp. strain BRSI56 degraded maximum. Our study suggests that for practical application, support of potential bacteria combined with the grasses is more effective approach than trees to remediate oil contaminated soils.

  6. Contrasting strategies to cope with drought conditions by two tropical forage C4 grasses

    PubMed Central

    Cardoso, Juan Andrés; Pineda, Marcela; Jiménez, Juan de la Cruz; Vergara, Manuel Fernando; Rao, Idupulapati M.

    2015-01-01

    Drought severely limits forage productivity of C4 grasses across the tropics. The avoidance of water deficit by increasing the capacity for water uptake or by controlling water loss are common responses in forage C4 grasses. Napier grass (Pennisetum purpureum) and Brachiaria hybrid cv. Mulato II are tropical C4 grasses used for livestock production due to their reputed resistance to drought conditions. However, there is scant information on the mechanisms used by these grasses to overcome water-limited conditions. Therefore, assessments of cumulative transpired water, shoot growth, leaf rolling, leaf gas exchange, dry mass production and a number of morpho-physiological traits were recorded over a period of 21 days under well-watered or drought conditions. Drought reduced shoot dry mass of both grasses by 35 %, yet each grass exhibited contrasting strategies to cope with water shortage. Napier grass transpired most available water by the end of the drought treatment, whereas a significant amount of water was still available for Mulato II. Napier grass maintained carbon assimilation until the soil was fairly dry, whereas Mulato II restricted water loss by early stomatal closure at relatively wet soil conditions. Our results suggest that Napier grass exhibits a ‘water-spending’ behaviour that might be targeted to areas with intermittent drought stress, whereas Mulato II displays a ‘water-saving’ nature that could be directed to areas with longer dry periods. PMID:26333827

  7. Population dynamics of caterpillars on three cover crops before sowing cotton in Mato Grosso (Brazil).

    PubMed

    Silvie, P J; Menzel, C A; Mello, A; Coelho, A G

    2010-01-01

    Direct seeding mulch-based cropping systems under a preliminary cover crop such as millet are common in some areas of Brazil. Lepidopteran pests that damage cotton, soybean and maize crops can proliferate on cover crops, so preventive chemical treatments are necessary. Very little data is available on these pests on cover crops. This paper presents the dynamics of Spodoptera frugiperda, S. eridania, Mocis latipes and Diatraea saccharalis caterpillars monitored at Primavera do Leste, Mato Grosso state (Brazil) during the of 2005/2006 and 2006/2007 cropping seasons on four cover crops, i.e. finger millet (Eleusine coracana), pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolor) and ruzigrass (Brachiaria ruziziensis). The pests were visually counted on plants within a 1 m2 transect (wooden frame). Caterpillars were reared to facilitate identification of collected species and parasitoids. Many S. frugiperda caterpillars were observed on millet in 2005, with a maximum of 37 caterpillars/m2. On sorghum, we found 30 caterpillars/m2, or 0.83 caterpillars/plant. The Diatraea borer attacked sorghum later than the other pests. M. latipes was also observed on millet. The millet cover crop had to be dried for at least 1 month before direct drilling the main cotton crop in order to impede S. frugiperda infestations on cotton plantlets, thus avoiding the need for substantial resowing. The comparative methodological aspects are discussed.

  8. [Performance and parasitologic infestation of male dairy cattle supplemented with proteic salt containing or not homeopathic medicines].

    PubMed

    Signoretti, Ricardo D; Veríssimo, Cecília José; De Souza, Fernando Henrique M; Garcia, Tamires Da S; De Oliveira, Elisa Marcela; De Souza, Karen G; Mourão, Gerson Barreto

    2008-09-01

    The objective of this study was to evaluate the performance and parasitologic infection of male dairy cattle submitted to supplemental proteic salt with and without the use of homeopathic medicines. Were used crossbred Gir x Holstein castrated males calves, with 10 months of age and live weight of 150.75 kg, distributed in a completely randomized design with eight replicates per treatment, totaling 16 animals. The calves of each treatment remained in a pasture of Brachiaria brizantha cv. Marandu, managed in continuous grazing system for 8 months. The treatments employed were: supplementation with 300 g/animal/day of protein (40% of crude protein (CP) and 25% CP in the dry and rainy season, respectively) added or not with 5 g/animal/day of the homeopathic medicines FATOR PRO® and C & MC®. The addition of homeopathic medicines in the protein supplement did not affect (P > 0.05) the development of body male crossbred to pasture. The counting of the larvae and adults of ticks in scrapings were lower (P < 0.05) in animals that did not receive homeopathic medicines in the protein supplement. The females tick in the body anterior third (simplifying counting), nymphs in scrapings and the number of eggs per gram of helminths were not affected (P > 0.05) by the treatments. It was concluded that the use of homeopathic medicines did not affect the development of male crossbred Gir x Holstein dairy cattle neither their parasitic infection.

  9. Carbon footprint related to cattle production in Brazil, management practices and new alternatives.

    NASA Astrophysics Data System (ADS)

    de Figueiredo, Eduardo; de oliveira, Ricardo; Berchielli, Telma; Reis, Ricardo; La Scala, Newton

    2013-04-01

    Brazil has the World largest commercial beef cattle herd, over 209.5 million heads in 2010 and is the leading exports of cattle meat. It has been argued that this activity has an important impact on GHG emissions, but a variety of options exists for greenhouse gases (GHG) mitigation in agriculture. Among those, the most prominent options are associated to the improvement of crops and grazing land management. Our study is focused on the GHG balance related to the improvement of brachiaria spp. pasture, leading to increases in the animal stocking rate and meat production per area and time. This study is based on the IPCC (2006) methodology and others Brazil specific data and results presented by scientific literature to estimate GHG balance (emissions sources and sinks) for three scenarios proposed for brachiaria pasture: 1) degraded pasture, 2) managed pasture and 3) crop-livestock-forest integration system (CLFIS). The approach takes into account the amounts of supplies per hectare used for each of the simulated scenario projected over a 20 years period. The GHG estimates are presented in kg CO2eq per kg of liveweight, considering the following emission sources and sinks within farm-gate: i) CH4 from enteric fermentation, ii) CH4 from manure deposited on pasture, iii) N2O emissions from urine and dung deposited by cattle on pasture, iv) N2O emissions from N synthetic fertilizer, v) N2O emissions from crop residues as of N-fixing crops and pasture renewal returned to soils, vi) CO2 from potassium use, vii) CO2 from phosphorus use, viii) CO2 from insecticides use, ix) CO2 from herbicides use, x) CO2 emissions due to lime application, xi) emissions due to diesel combustion, xii) eucalyptus biomass sequestration and xiii) soil carbon sequestration. We considered initial body weight of 200 kg for each heifer and a final slaughter weight of 450 kg head-1 for all scenarios; for degraded pasture a stocking rate of 0,5 head ha-1 year-1 and liveweight gain of 83 kg head-1

  10. Changes in Carbon Emissions in Colombian Savannas Derived From Recent Land use and Land Cover Change

    NASA Astrophysics Data System (ADS)

    Etter, A.; Sarmiento, A.

    2007-12-01

    ,500 Ha among the different savanna ecosystem types. Highest frequencies and largest burned areas occur in the less accessible well-drained savannas of the southern part of the region. The analysis also reveals a close relationship between land tenure and fire regimes, with highest frequencies in Indigenous Reserves, followed by private land ranches and National Parks, indicating that most fires are human induced. By 2000 more than 500k hectares of natural savannas were transformed to sown pastures (Brachiaria spp.), and some 100k hectares were planted with oil palm and irrigated rice. Such changes have taken place in more accessible areas and slightly better soils. In areas subject to land use change and intensification a significant reduction in fire frequency can be observed. Because such land use changes have been occurring in savanna types with better soils and higher aerial biomass values, the average effect on reduction of C-emissions is some 30 to 50% larger than the effect on fire area reduction. Our results indicate a reduction of fire frequencies greater than 80% in areas where savannas were replaced by introduced Brachiaria pastures. However the reduction in C emissions from fire reduction in these pastures is exceeded by the parallel emissions from the increase in the cattle stocking rates with a net effect of an additional emission of 0.5 Gt.CO2 equivalents. We make preliminary projections of future emission trends based on the land use change model, and we discuss the likely effects of future sources and sinks of C expected from the increase of irrigated rice crops and from projected oil palm and timber plantations.

  11. Seasonal change in CO2 and H2O exchange between grassland and atmosphere

    NASA Astrophysics Data System (ADS)

    Saigusa, N.; Liu, S.; Oikawa, T.; Watanabe, T.

    1996-03-01

    The seasonal change in CO2 flux over an artificial grassland was analyzed from the ecological and meteorological point of view. This grassland contains C3 and C4 plants; the three dominant species belonging to the Gramineae; Festuca elatior (C3) dominated in early spring, and Imperata cylindrica (C4) and Andropogon virginicus (C4) grew during early summer and became dominant in mid-summer. CO2 flux was measured by the gradient method, and the routinely observed data for the surface-heat budget were used to analyze the CO2 and H2O exchange between the grassland and atmosphere. From August to October in 1993, CO2 flux was reduced to around half under the same solar-radiation conditions, while H2O flux decreased 20% during the same period. The monthly values of water use efficiency, i.e., ratio of CO2 flux to H2O flux decreased from 5.8 to 3.3 mg CO2/g H2O from August to October, the Bowen ratio increased from 0.20 to 0.30, and the ratio of the bulk latent heat transfer coefficient CE to the sensible heat transfer coefficient CH was maintained around 0.40-0.50. The increase in the Bowen ratio was explained by the decrease in air temperature from 22.3 °C in August to 16.6 °C in October without considering biological effects such as stomatal closure on the individual leaves. The nearly constant CE/CH ratios suggested that the contribution ratio of canopy resistance to aerodynamic resistance did not change markedly, although the meteorological conditions changed seasonally. The decrease in the water use efficiency, however, suggested that the photosynthetic rate decreased for individual leaves from August to October under the same radiation conditions. Diurnal variations of CO2 exchange were simulated by the multi-layer canopy model taking into account the differences in the stomatal conductance and photosynthetic pathway between C3 and C4 plants. The results suggested that C4 plants played a major role in the CO2 exchange in August, the contribution of C4 plants

  12. Guanaco traces and hunting strategies at Alto Patache North Chilean fog oasis

    NASA Astrophysics Data System (ADS)

    Larrain, H.; Cereceda, P.; Pérez, L.

    2010-07-01

    1. In foregoing Fog Conferences, some of us have made explicit the rich botanic and faunistic inventory to be found at this Chilean Fog site. This was specially apparent under strong ENSO conditions, as it happened in 1997/98 in the area. Among the mammal biggest species represented, the guanaco (Lama guanicoe Müller) merits special mention. Clear traces of their presence and eventual hunting and slaughtering by primitive populations have survived until present times. Among them, the myriads of guanaco trails still covering practically all the slopes along the foggy area, close to the sea, and their wollowing and defecating places are found. Also, although less studied, plant eating traces left behind by roaming camelids can be seen. 2. Guanaco hunting traces still visible at Alto Patache can be portrayed differently through : A) Analysis of lithic artifacts used as arms in hunting operations; B) Botanic response to animal attack; C) Examination of topographic traits used by primitive man in guanaco hunting strategies. A. Hundreds of lithic instruments made of stone, were abandoned by hunters in situ, some of them were intact, some fragmented, which would demonstrate a direct relationship with hunting and slaughtering, and also their elaboration in workshops at place. Lithic points, scrapers and knives were found at places specially apt for hunting or slaughtering activities. Total isolation of the mountain fog site previous to our arrival in 1996, favoured their conservation at place. B. Careful observation of some local plants showed clear traces of guanaco feeding habits. As a proof thereof, old cactus of the species Eulychnia iquiquensis show in their basal portions clear signals in the forms of scars, caused by the eating by guanacos. Guanaco faeces were found at the foot of Ephedra plants. Many dead Stipa ichu plants (Gramineae), in different areas of the oasis provide evidence of cutting close to their basis, caused by sharp guanaco tooth under severe food

  13. Aploneura lentisci (Homoptera: Aphididae) and Its Interactions with Fungal Endophytes in Perennial Ryegrass (Lolium perenne)

    PubMed Central

    Popay, Alison J.; Cox, Neil R.

    2016-01-01

    Aploneura lentisci Pass. is endemic to the Mediterranean region where it is holocyclic, forming galls on its primary host, Pistacia lentiscus and alternating over a 2-year period between Pistacia and secondary hosts, principally species of Gramineae. This aphid is widely distributed in Australia and New Zealand on the roots of the common forage grasses, ryegrass (Lolium spp.) and tall fescue (Schedonorus phoenix) where it exists as permanent, anholocyclic, parthenogenetic populations. Previous studies have indicated that infestations of A. lentisci significantly reduce plant growth and may account for differences in field performance of Lolium perenne infected with different strains of the fungal endophyte Epichloë festucae var. lolii. These obligate biotrophs protect their host grasses from herbivory via the production of alkaloids. To confirm the hypothesis that growth of L. perenne is associated with the effect of different endophyte strains on aphid populations, herbage and root growth were measured over time in two pot trials that compared three fungal endophyte strains with an endophyte-free control. In both pot trials, aphid numbers were lowest on plants infected with endophyte strain AR37 at all sampling times. In plants infected with a common toxic strain naturalized in New Zealand, aphid numbers overall were lower than on uninfected plants or those infected with strain AR1, but numbers did not always differ significantly from these treatments. Populations on AR1-infected plants were occasionally significantly higher than those on endophyte-free. Cumulative foliar growth was reduced in AR1 and Nil treatments relative to AR37 in association with population differences of A. lentisci in both trials and root dry weight was reduced in one trial. In four Petri dish experiments survival of A. lentisci on plants infected with AR37 declined to low levels after an initial phase of up to 19 days during which time aphids fed and populations were similar to those on

  14. Relationship between Pollen Counts and Weather Variables in East-Mediterranean Coast of Turkey

    PubMed Central

    Karakoç, Gülbin Bingöl; Yilmaz, Mustafa; Pinar, Münevver; Kendirli, Seval Güneçer; Çakan, Halil

    2004-01-01

    Background: Aeroallergen sampling provides information regarding the onset, duration and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment. Objectives: This atmospheric survey reports (1) airborne pollen contributions in Adana in one-year period (2) pollen onset, duration and peak level (3) the relationship between airborne pollen and selected meteorological variables and; (4) effects on symptoms in pollen allergic children. Methods: Pollen sampling was performed with a volumetric Burkard Spore Trap. Meteorological data were measured daily from April 2001 to April 2002. Asthma symptom scores were investigated in 186 pollen allergic children that were on follow up in pediatric allergy outpatient clinics during same period. Results: Average measurements included 82.5% tree pollen, 7.7% grass pollen and 9.8% herb pollen 54 taxa were identified during one year. The most prominent tree pollens were Cupressaceae, Eucalyptus and Pinus. The most common herb was Chenopodiaceae pollen family. When airborne pollen levels were examined in relation to single meteorological conditions; daily variations in total pollen counts were not significantly correlated with any variable studied (humidity, rainfall, temperature and wind) (p>0.05). On the other hand, statistically significant relationship between pollen concentration and symptom scores were found (p>0.05). Positive correlations were seen between both Gramineae and Herb pollen, and humidity and rainfall from March to July. However, positive correlations were detected between tree pollen counts and temperature and humidity in May and June. Conclusion: This survey is the first volumetric airborne pollen analysis conducted in the survey area in Adana. This study suggested that the effects of weather on pollen count and symptom scores in this population could not be clearly identified with the evaluation of one-year data. However, pollen counts had effect on allergic

  15. Recent pollen spectra and zonal vegetation in the western USSR

    NASA Astrophysics Data System (ADS)

    Peterson, G. M.

    The relationship of modern pollen spectra to present-day vegetation is critical to the reconstruction of vegetation and climate from fossil pollen spectra. This study uses isopoll maps to illustrate the pollen-vegetation relationships in the Soviet Union west of 100°E and presents descriptive statistics for 544 modern samples of arboreal pollen and for 370 samples of herb pollen obtained from the Soviet palynological literature. Data are assembled from this large geographic region and presented in a standardized form on a scale which can be used to relate quantitative pollen data to zonal vegetation and climatic variables and to make comparisons with other regions. In order to show the relationship between pollen types and major ecotones in forested and non-forested areas, the pollen data are presented as percentages of a sum including both arboreal and non-arboreal pollen. Major pollen types which attain values of 10% or more in at least one vegetation zone include Betula (birch), Cyperaceae (sedges), Picea (spruce), Pinus (total pine), Pinus sibirica, Ericaceae (heath family), Gramineae (grasses), Artemisia (sage), and Chenopodiaceae (i.e., saltbush, Russian thistle, pigweed family). Samples from the tundra and forest-tundra have high values of Ericaceae (heath family), birch, alder, and sedge pollen. In the boreal forest, pine, spruce, and birch pollen predominate. In the mixed and deciduous forests, Tilia (linden), Quercus (oak), Ulmus (elm), and Corylus (hazel) pollen attain maximum values. In the forest-steppe and steppe zones, arboreal pollen decreases in importance and is replaced by non-arboreal pollen types. Pollen of Artemisia and Chenopodiaceae predominates in the semi-desert zones. In spite of variation in the pollen spectra arising from the use of different sediment types (soil, peat, and river sediments), and human disturbance of vegetation, the pollen spectra are clearly related to zonal vegetation. Pollen spectra from the western USSR show

  16. Growth and cell wall changes in stem organs under microgravity and hypergravity conditions

    NASA Astrophysics Data System (ADS)

    Hoson, Takayuki; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro

    Gravity strongly influences plant growth and development, which is fundamentally brought about by modifications to the properties of the cell wall. We have examined the changes in growth and cell wall properties in seedling organs under hypergravity conditions produced by centrifugation and under microgravity conditions in space. Hypergravity stimuli have been shown to decrease the growth rate of various seedling organs. When hypergravity suppressed elongation growth, a decrease in cell wall extensibility (an increase in cell wall rigidity) was induced. Hypergravity has also been shown to increase cell wall thickness in various mate-rials. In addition, a polymerization of certain matrix polysaccharides was brought about by hypergravity: in dicotyledons hypergravity increased the molecular size of xyloglucans, whereas hypergravity increased that of 1,3,1,4-β-glucans in monocotyledonous Gramineae. These mod-ifications to cell wall metabolism may be responsible for a decrease in cell wall extensibility, leading to growth suppression under hypergravity conditions. How then does microgravity in-fluence growth and cell wall properties? Here, there was a possibility that microgravity might induce changes similar to those by hypergravity, because plants have evolved and adapted to 1 g condition for more than 400 million years. However, the changes observed under microgravity conditions in space were just opposite to those induced by hypergravity: stimulation of elonga-tion growth, an increase in cell wall extensibility, and a decrease in cell wall thickness as well as depolymerization of cell wall polysaccharides were brought about in space. Furthermore, growth and cell wall properties varied in proportion to the logarithm of the magnitude of grav-ity in the range from microgravity to hypergravity, as shown in the dose-response relation in light and hormonal responses. Thus, microgravity may be a `stress-less' environment for plant seedlings to grow and develop

  17. Holocene Enviromental Changes in AN Amazonian Floodplain Lake

    NASA Astrophysics Data System (ADS)

    Moreira, L.; Moreira-Turcq, P. F.; Turcq, B.; Cordeiro, R. C.

    2011-12-01

    The floodplains lakes are built due to the fluctuations in the level of the rivers, which causes the formation of bars and accumulation of sediment carried by the rivers and its tributaries. Thus, significant quantities of organic matter can accumulate within these lakes that might represent important carbon sinks. The organic sedimentation process in the floodplains remains unknown as well as very little is known about past conditions in the Amazonian floodplains. Because these gaps, the aim of this work is to provide, through sedimentological, mineralogical and organic geochemical analysis of a 124-cm long core collected in Lago Comprido (eastern Amazonia), evidences of paleoenviromental changes during the Holocene. The core COM1 was analysed using radiocarbon dates, organic carbon concentration, C/N ratio, delta 13C and diatoms. The core points out different sedimentary environments that occurs in the last 9900 years cal BP. The record is divided into three phases: - phase III (124-94 cm, 9900 to 3200 cal years BP): this interval is characterized by delta 13C values typical of graminea, suggesting dry conditions with longer low water levels of the Amazon River. Supporting evidence for driest conditions during this period comes from low organic carbon values due to oxidation and absence of diatoms in the sediment. The carbon flux was very low, reaching an average of 0.9 g C/m2/year. - phase II (93-46 cm, 3200 to 940 years cal BP): increasing lake level beginning in this phase. The delta 13C values ranged between -25% and -29%, which are thought to represent terrestrial plants. This may indicate the presence of a flooded vegetation in this site. The freshwater planktonic diatoms Aulacoseira sp start to increase in this phase, additional evidence that the period of the annual high water stands was probably longer than before. Carbon flux increases, reaching an average of 5 g C/m2/year. - phase I (45-0cm, < 940 years cal BP): the delta 13C values and CN ratios did

  18. Studies in Neotropical Paleobotany. XV. A Mio-Pliocene palynoflora from the Eastern Cordillera, Bolivia: implications for the uplift history of the Central Andes.

    PubMed

    Graham, A; Gregory-Wodzicki, K M; Wright, K L

    2001-09-01

    An assemblage of 33 fossil pollen and spores, recovered from the 3600-m high Pislepampa locality of E. W. Berry, Eastern Cordillera, Bolivia, adds considerably to our knowledge of three aspects of the region in late Neogene time: (1) the paleovegetation, (2) the paleoclimate, and (3) the paleoelevation of the Central Andes. The plant microfossils recognized are Isoetes, Lycopodium (three types), Cnemidaria, Cyathea (three types), Grammitis, Hymenophyllum, Pteris, trilete fern spores (two types), Danaea, monolete fern spores (four types), Podocarpus, Gramineae, Palmae, Ilex, cf. Oreopanax, Cavanillesia, cf. Pereskia, Compositae (three types), Ericaceae, Tetrorchidium, and unknowns (three types). The diversity of the Compositae suggest that this flora has a maximum age around the Miocene-Pliocene boundary, that is, 6-7 million years. All members of the paleocommunity presently grow in the bosque montano húmedo (cloud forest) along the eastern slope of the Central Andes of Bolivia, which occurs between MATs (mean annual temperatures) of ∼10° and 20°C. The Pislepampa flora probably represents the lower limits of this forest because the fossil leaves collected by Berry from the same locality all have entire margins, suggesting that the flora grew near the cloud forest-tropical forest transition. Presently, the lower limit of the cloud forest forest has MATs of ∼20°C, a mean annual precipitation between 1000 and 1500 mm, and that part containing most of the identified genera of fossil pollen is found at elevations ∼1200-1400 m. These conditions are thus inferred for the Pislepampa flora; however, because of the uncertainty of the magnitude of global climate change and of possible changes in the ecological range of plant genera, we estimate an error of at least ±1000 m for the paleoelevation estimate. When the total uplift is corrected for probable amounts of erosionally driven isostatic rebound, the paleoelevation estimate suggests that from one-third to one

  19. The Neogene Environment of the Beardmore Glacier, Transantarctic Mountains

    NASA Astrophysics Data System (ADS)

    Ashworth, A. C.; Cantrill, D. J.; Francis, J. E.; Roof, S. R.

    2004-12-01

    Discontinuous sequences of Neogene marine and non-marine glacigenic sequences, including the Meyer Desert Formation (MDF), occur throughout the Transantarctic Mountains. The upper 85m of the MDF, consisting of interbedded diamictites, conglomerates, sandstones and siltstones, outcrops in the Oliver Bluffs on the Beardmore Glacier at 85° 07'S, 166° 35'E. The location is about 170 km south of the confluence of the Beardmore Glacier with the Ross Ice Shelf and about 500 km north of the South Pole The glacial, fluvioglacial and glaciolacustrine facies of the MDF represent a dynamic glacial margin which advanced and retreated on at least four occasions. On at least one occasion, the retreat was sufficiently long for plants and animals to colonize the head of a major fjord which existed in the place of the existing Beardmore Glacier. From the fossils we have identified at least 18 species of plants, 3 species of insects, 2 species of freshwater mollusks, and a species of fish. The plant fossils consist of pollen, seeds, fruits, flowers, leaves, wood, and in situ plants. The plants include a cryptogamic flora of mosses and liverworts, conifers, and angiosperms in the families Gramineae, Cyperaceae, Nothofagaceae, Ranunculaceae, Hippuridaceae, ?Caryophyllaceae, and ?Chenopodiaceae or ?Myrtaceae. The plants grew in a weakly developed soil developed on a complex periglacial environment that included moraines, glacial outwash streams, well-drained gravel ridges, and poorly drained depressions in which peat and marl were being deposited. The fossil assemblage represents a mosaic tundra environment of well- and poorly-drained micro-sites, in which nutrient availability would have been patchily distributed. Antarctica has been essentially in a polar position since the Early Cretaceous and at 85° S receives no sunlight from the middle of March until the end of September. Today, the annual radiation received is about 42% that of Tierra del Fuego at 55° S. During the Neogene

  20. [Species-dependence of the pattern of plant photosynthetic rate response to light intensity transition from saturating to limiting one].

    PubMed

    Chen, Yue; Xu, Da-Quan

    2007-12-01

    By observing the photosynthetic responses of leaves to changes in light intensity and CO(2) concentration it was found that among the more than 50 plant species examined 32 species and 25 species showed respectively the V pattern and L pattern of the photosynthetic response to light intensity transition from saturating to limiting one (Figs.1 and 2 and Table 1). The pattern of photosynthetic response to light intensity transition is species-dependent but not leaf developmental stage-dependent (Fig.3). The species-dependence was not related to classification in taxonomy because the photosynthetic response might display the two different patterns (V and L) in plants of the same family, for example, rice and wheat (Gramineae), soybean and peanut (Leguminosae). It seemed to be related to the pathway of photosynthetic carbon assimilation because all of the C(4) plants examined (maize, green bristlegrass and thorny amaranth) displayed the L pattern. It might be related to light environment where the plants originated. The V pattern of photosynthetic response to light intensity transition was often observed in some plants grown in shade habitats, for example, sweet viburnum and Japan fatsia, while the L pattern was frequently observed in those plants grown in sunny habitats, for example, ginkgo and cotton. Furthermore, the ratio of electron transport rate to carboxylation rate in vivo measured at limiting light was far higher in the V pattern plants (mostly higher than 10) than in the L pattern plants (mostly lower than 5), but the ratio measured at saturating light had no significant difference between the two kinds of plants (Table 2). These results can be explained in part by that the V pattern plant species have larger light-harvesting complex (LHCII) and at saturating light the reversible dissociation of some LHCIIs from PSII reaction center complex occurs. The pattern of photosynthetic response to light intensity transition and the ratio of electron transport rate

  1. Last glacial pollen record from Lanzhou (Northwestern China) and possible forcing mechanisms for the MIS 3 climate change in Middle to East Asia

    NASA Astrophysics Data System (ADS)

    Jiang, Hanchao; Mao, Xue; Xu, Hongyan; Thompson, Jessica; Wang, Ping; Ma, Xiaolin

    2011-03-01

    The vegetation on the northeastern margin of the Tibetan Plateau is highly sensitive to climatic changes and thus represents a potentially interesting environmental archive. Pollen samples from the Fanjiaping Loess section in Lanzhou on the western Chinese Loess Plateau (CLP) were analyzed in conjunction with OSL dating. The results indicate that pollen zone B (60.6-46.0 ka, correlative to the early MIS 3) had the greatest abundances of Cupressaceae, Tsuga, Gramineae and Cyperaceae of the entire section, suggesting a warm phase during the last glacial period. These pollen taxa decreased significantly in abundance in the zones C (46.0-39.0 ka) and D (39.0-27.0 ka), reflecting a substantial climate cooling from the middle MIS 3 to MIS 2. These results correlate with climate records from the South China Sea, the CLP, Baikal Lake, North America, North Atlantic Ocean and other regions, and probably correspond with the decline of northern high-latitude insolation and the increase of global ice volume from 50 to 20 ka. In particular, arboreal pollen, fern spore and algae abundances declined sharply since ˜40 ka, while shrub and herb pollen reached the highest abundances. Conifer pollen Picea and Abies abundance also rose markedly and increased up the section. This implies significant climate deterioration and likely corresponded with substantial growth of the polar ice sheets since ˜40 ka. The decreasing temperature caused by an insolation decline during the last glacial period probably reinforced the cooling effect in a 'snow/ice/albedo' feedback, which would result in less climate sensitivity to radiative forcing. Meanwhile, vegetation decline in the Northern Hemisphere during the last glacial period and tundra development at high latitudes possibly caused additional cooling, enhancing the growth of polar ice sheets since 40 ka. The development of polar ice sheets increased the polar-to-equator temperature and pressure gradients, strengthening the westerlies and

  2. Dung beetles (Coleoptera: Scarabaeidae) attracted to dung of the largest herbivorous rodent on earth: a comparison with human feces.

    PubMed

    Puker, Anderson; Correa, César M A; Korasaki, Vanesca; Ferreira, Kleyton R; Oliveira, Naiara G

    2013-12-01

    The capybara, Hydrochoerus hydrochaeris (L.) (Rodentia: Caviidae), is the largest herbivorous rodent on Earth and abundant in the Neotropical region, which can provide a stable food source of dung for dung beetle communities (Coleoptera: Scarabaeidae: Scarabaeinae). However, the use of capybara dung by dung beetles is poorly known. Here, we present data on the structure of the dung beetle community attracted to capybara dung and compare with the community attracted to human feces. Dung beetles were captured with pitfall traps baited with fresh capybara dung and human feces in pastures with exotic grass (Brachiaria spp.), patches of Brazilian savanna (Cerrado), and points of degraded riparian vegetation along the Aquidauana river in Anastácio and Aquidauana, Mato Grosso do Sul, Brazil. In traps baited with human feces, 13,809 individuals of 31 species were captured, and in those baited with capybara dung 1,027 individuals belonging to 26 species were captured. The average number of individuals and species captured by the traps baited with human feces was greater than for capybara dung in all habitats studied. Composition of the communities attracted to human feces and capybara dung formed distinct groups in all habitats. Despite the smaller number of species and individuals captured in capybara dung when compared with human feces, capybara dung was attractive to dung beetles. In Brazil, the legalization of hunting these rodents has been debated, which would potentially affect the community and consequently the ecological functions performed by dung beetles that use the feces of these animals as a resource. In addition, the knowledge of the communities associated with capybaras may be important in predicting the consequences of future management of their populations.

  3. Intake, digestibility and rumen dynamics of neutral detergent fibre in cattle fed low-quality tropical forage and supplemented with nitrogen and/or starch.

    PubMed

    Souza, Marjorrie A; Detmann, Edenio; Paulino, Mário F; Sampaio, Cláudia B; Lazzarini, Isis; Valadares Filho, Sebastião C

    2010-08-01

    The objective of this work was to evaluate the effects of nitrogenous compounds and/or starch supplementation on the intake, digestibility and rumen dynamics of neutral detergent fibre (NDF) in cattle fed low-quality tropical forage. Four crossbred heifers (Holstein x Zebu) with a body weight 231.9 +/- 15.5 kg and fitted with ruminal cannulae were used. The forage fed to the animals consisted of low-quality signal grass (Brachiaria decumbens Stapf.) hay, with an average crude protein (CP) level of 51.6 g/kg, on a dry matter (DM) basis. Four treatments were evaluated: control, without supplementation; supplementation with nitrogenous compounds (CP of the roughage was raised to 100 g/kg), on a DM basis; supplementation with starch at a ratio of 200 g/kg DM of roughage; and supplementation with nitrogenous compounds and starch as described above. A mixture of urea, ammonium sulphate and albumin was used as a source of nitrogenous compounds at a ratio of 4.5:0.5:1.0. The experiment was carried out according to a 4 x 4 Latin square design in a 2 x 2 factorial arrangement. There was a positive effect of the nitrogenous compound supplementation on the DM and NDF intake (P < 0.01). In contrast, starch supplementation decreased forage intake (P < 0.10). Nitrogen supplementation increased the digestibility coefficient of DM and NDF (P < 0.05). Supplementation with nitrogen and starch together increased the microbial assimilation of nitrogenous compounds in the rumen (P < 0.05). We observed that nitrogen supplementation increased the estimated weighted degradation rate of NDF by 14.8%, whilst starch supplementation decreased this rate by 32.5%.

  4. Intake and digestibility in cattle fed low-quality tropical forage and supplemented with nitrogenous compounds.

    PubMed

    Sampaio, Claudia B; Detmann, Edenio; Paulino, Mario F; Valadares Filho, Sebastiao C; de Souza, Marjorrie A; Lazzarini, Isis; Paulino, Pedro V Rodrigues; de Queiroz, Augusto C

    2010-10-01

    The effects of supplementation with nitrogenous compounds on intake, digestibility, and microbial protein synthesis in cattle fed low-quality tropical forage were assessed. Five rumen fistulated crossbred Holstein x Gir heifers were used, with initial average live weight of 180 +/- 21 kg. Signal grass (Brachiaria decumbens) hay (48.6 g kg(-1) of crude protein (CP), on a dry matter (DM) basis) was used as roughage. Five treatments were defined according to nitrogen supplementation level (0, 20, 40, 60, and 80 g of CP kg(-1) above the CP level of the hay). A mixture of urea, ammonium sulfate, and albumin at the ratios of 4.5:0.5:1.0, respectively, was used as nitrogen source. The experiment consisted of five experimental periods, according to a 5 x 5 Latin square design. The average CP contents in the diets were 51.9, 71.1, 86.0, 116.7, and 130.2 g kg(-1), on a DM basis. A quadratic effect was detected (P < 0.10) of the CP levels in the diets on DM and neutral detergent fiber intake (kg/day), with maximum response at the levels of 102.4 and 100.5 g CP kg(-1) DM, respectively. The average daily concentration of rumen ammonia nitrogen showed increasing linear pattern (P < 0.01) as function of CP levels in the diet, with estimated value of 9.64 mg dL(-1) equivalent to the maximum DM intake. Microbial nitrogen flow in the intestine was linearly and positively related (P < 0.01) with the CP levels in the diet.

  5. Methane Production of Different Forages in In vitro Ruminal Fermentation

    PubMed Central

    Meale, S. J.; Chaves, A. V.; Baah, J.; McAllister, T. A.

    2012-01-01

    An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on CH4 production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, Gliricidia sepium, Leucaena leucocephala and Stylosanthes guianensis and non-leguminous shrub species included Annona senegalensis, Moringa oleifera, Securinega virosa and Vitellaria paradoxa. Leaves were harvested, dried at 55°C and ground through a 1 mm screen. Serum bottles containing 500 mg of forage, modified McDougall’s buffer and rumen fluid were incubated under anaerobic conditions at 39°C for 24 h. Samples of each forage type were removed after 0, 2, 6, 12 and 24 h of incubation for determination of cumulative gas production. Methane production, ammonia concentration and proportions of VFA were measured at 24 h. Concentration of aNDF (g/kg DM) ranged from 671 to 713 (grasses), 377 to 590 (leguminous shrubs) and 288 to 517 (non-leguminous shrubs). After 24 h of in vitro incubation, cumulative gas, CH4 production, ammonia concentration, proportion of propionate in VFA and IVDMD differed (p<0.05) within each forage type. B. ruziziensis and G. sepium produced the highest cumulative gas, IVDMD, total VFA, proportion of propionate in VFA and the lowest A:P ratios within their forage types. Consequently, these two species produced moderate CH4 emissions without compromising digestion. Grazing of these two species may be a strategy to reduce CH4 emissions however further assessment in in vivo trials and at different stages of maturity is recommended. PMID:25049482

  6. Oxisol decapitated recovery with green manure and sewage sludge: Effect on growth of Astronium fraxinifolium

    NASA Astrophysics Data System (ADS)

    Souto Filho, S. N.; Marchini, D. C.; de Arruda, O. G.; Giácomo, R. G.; Alves, M. C.

    2012-04-01

    Incorrect use of land and large buildings in rural areas are causing changes to it, making them less productive and thus increasing the degraded areas. Techniques aimed at ecological restoration of degraded soils have been investigated. In recovery planning a degraded area, the great challenge to be achieved is the establishment of a A horizon, so that from then on, the process is catalyzed by the biosphere, and there may be other horizons, as the natural conditioning. In this sense the positive changes were investigated in an environment of decapitated Savannah Oxisol, which was removed a layer 8.5 m thick to build a hydroelectric power plant. For recovery, we used a native tree species, green manure, sewage sludge and grass. The studied soil is under human intervention techniques for recovery for seven years. The experimental design was randomized blocks with five treatments and five replications. The treatments were: 1-Control- bare soil (without management), 2-Astronium fraxinifolium Schott; 3-A. fraxinifolium + Canavalia ensiformis; 4- A. fraxinifolium + Raphanus sativus by 2005 was replaced in 2006 by Crotalaria juncea; 5- A. fraxinifolium + Brachiaria decumbens + sewage sludge (60 t ha-1, dry basis). We studied in 2010 and 2011 the development of tree species (stem diameter and plant height), the fresh and dry matter of green manures and B. decumbens. The results were analyzed by performing the variance analysis and Tukey test at 5% probability to compare averages. The rate of plant growth during the periods studied in the treatment with sewage sludge was higher than other treatments, so this is the most appropriate management for the recovery of degraded soil under study.

  7. Acaricidal activity of thymol against larvae of Rhipicephalus microplus (Acari: Ixodidae) under semi-natural conditions.

    PubMed

    Araújo, Laryssa Xavier; Novato, Tatiane Pinheiro Lopes; Zeringota, Viviane; Matos, Renata Silva; Senra, Tatiane Oliveira Souza; Maturano, Ralph; Prata, Márcia Cristina Azevedo; Daemon, Erik; Monteiro, Caio Márcio Oliveira

    2015-09-01

    This is the first study to investigate the activity of thymol on Rhipicephalus microplus larvae under semi-natural conditions. For this purpose, tests were conducted in pots with Brachiaria decumbens seedlings containing cattle tick larvae. Thymol, diluted in ethanol 50° GL, was tested at concentrations of 2.5, 5.0, 10.0, 15.0, and 20.0 mg/mL, along with the control group treated with the solvent alone. Each treatment was composed of five pots (1 pot = a repetition). The experiment was performed in three steps. On the first day, the larvae were applied at the base of the signalgrass. Twenty-four hours later, approximately 25 mL of the solution was applied with thymol on the top of the vegetation in each pot. The survival of the larvae was measured 24 h after application of the solutions. Each pot was analyzed individually, and the grass fillets contained larvae were cut with scissors, placed in Petri dishes, and taken to the laboratory to count the number of living larvae. At the highest concentrations (10, 15, and 20 mg /mL), the number of live larvae declined by more than 95 % in relation to the control group. The lethal concentration 50 % (LC50) and LC90 values were 3.45 and 9.25 mg/ml, respectively. The application of thymol in semi-natural conditions starting concentration of 10 mg/mL significantly reduced the number of living R. microplus larvae.

  8. A paradigm shift towards low-nitrifying production systems: the role of biological nitrification inhibition (BNI)

    PubMed Central

    Subbarao, G. V.; Sahrawat, K. L.; Nakahara, K.; Rao, I. M.; Ishitani, M.; Hash, C. T.; Kishii, M.; Bonnett, D. G.; Berry, W. L.; Lata, J. C.

    2013-01-01

    Background Agriculture is the single largest geo-engineering initiative that humans have initiated on planet Earth, largely through the introduction of unprecedented amounts of reactive nitrogen (N) into ecosystems. A major portion of this reactive N applied as fertilizer leaks into the environment in massive amounts, with cascading negative effects on ecosystem health and function. Natural ecosystems utilize many of the multiple pathways in the N cycle to regulate N flow. In contrast, the massive amounts of N currently applied to agricultural systems cycle primarily through the nitrification pathway, a single inefficient route that channels much of this reactive N into the environment. This is largely due to the rapid nitrifying soil environment of present-day agricultural systems. Scope In this Viewpoint paper, the importance of regulating nitrification as a strategy to minimize N leakage and to improve N-use efficiency (NUE) in agricultural systems is highlighted. The ability to suppress soil nitrification by the release of nitrification inhibitors from plant roots is termed ‘biological nitrification inhibition’ (BNI), an active plant-mediated natural function that can limit the amount of N cycling via the nitrification pathway. The development of a bioassay using luminescent Nitrosomonas to quantify nitrification inhibitory activity from roots has facilitated the characterization of BNI function. Release of BNIs from roots is a tightly regulated physiological process, with extensive genetic variability found in selected crops and pasture grasses. Here, the current status of understanding of the BNI function is reviewed using Brachiaria forage grasses, wheat and sorghum to illustrate how BNI function can be utilized for achieving low-nitrifying agricultural systems. A fundamental shift towards ammonium (NH4+)-dominated agricultural systems could be achieved by using crops and pastures with high BNI capacities. When viewed from an agricultural and

  9. Evaluation of local energy sources in milk production in a tropical silvopastoral system with Erythrina poeppigiana.

    PubMed

    Jiménez-Ferrer, Guillermo; Mendoza-Martínez, Germán; Soto-Pinto, Lorena; Alayón-Gamboa, Armando

    2015-06-01

    An experiment was carried out to determine the effect of four local energy sources (sorghum grain, green banana, polished rice, and sugarcane molasses) fed to dairy cows on intake, milk production and composition, and economic viability in a silvopastoral system in Costa Rica (Turrialba). Twelve grazing cows (Jersey × Central American Milking Creole), with a mean live weight of 332 kg (SD 34), were supplemented with 0.5 kg of dry matter (DM)/100 kg/LW of Erythrina porppigiana fresh foliage daily. Experimental design was a replicated change-over 4 × 4 Latin Square. The pasture composition was 11 and 17 % of star grass (Cynodon niemfuensis), 32 and 28 % of ruzzi grass (Brachiaria rusisiensis), and 45 and 42 % of natural grasses (Axonopus compresus and Paspalum conjugatum) at initial and final times of the essay, respectively. The grass allowance was 30.14 DM/cow/day. Significant differences were found among treatments for variable milk fat content (P < 0.05). Sorghum presented the highest (41.2 g/kg milk) content of milk fat, followed by green banana (39.2 g/kg milk), polished rice (38.3 g/kg milk) and molasses (38.1 g/kg milk). Non-significant differences (P > 0.05) resulted for total milk production (sorghum 9.0 kg/cow/day; green banana 8.9 kg/cow/day; polished rice 8.8 kg/cow/day; molasses 8.6 kg/cow/day) and fat-corrected milk (FCM). The financial analysis showed that all treatments were economically viable; however, supplementation with green bananas and molasses were the most favorable due to the low costs incurred.

  10. Assessment of land use in protected areas of the state of Sao Paulo, Brazil

    NASA Astrophysics Data System (ADS)

    Iori, P.; da Silva, R. B.; Dias Junior, M. S.; Paz González, A.

    2012-04-01

    It is of universal knowledge that the soil, a basic natural resource, is renewable only if conserved or used correctly(Primavesi, 2002). It is salient for Araújo et al. (2007) that the establishment of index of soil quality is an important tool in the functions of control, supervision and monitoring of areas for environmental protection. The objective of this study was to compare the quality of the soil by means of a comparative diagram in different soil uses in permanent preservation areas (APP). The study was conducted in areas near the Ribeira de Iguape river in the city of Registro - São Paulo - Brazil, belonging to the Atlantic Forest domain, a Haplic Cambisol. The following uses of the soil had been evaluated: a) banana culture (CBAN) without agricultural traffic of machines; b) degraded pasture (PDEG) with extensive system predominantly Brachiaria decumbens L. c) use silvopastoral (MPIs), consisted in a kills with a traffic free for the animals, and d) native vegetation (MNAT), proposed in this study as a reference area.The following physical indicators were analyzed: bulk density (BD), total soil porosity (TP), macroporosity (Ma), microporosity (Mi), water dispersible clay (ADA), flocculation index (FI), preconsolidation pressure (PP), soil shear strength (SS), soil resistance to penetration (RP). To construct the comparative diagram the values for each attribute of the soil in each land use were related to the values of the native forest. It was feasible to use the comparative model in the qualitative evaluation of soil use, allowing separate environments under different uses. According to the comparative diagram of banana culture is the use that most negatively impacts the physical and mechanical soil due to the smaller size of the lower polygon.

  11. Plant species affect colonization patterns and metabolic activity of associated endophytes during phytoremediation of crude oil-contaminated soil.

    PubMed

    Fatima, K; Imran, A; Amin, I; Khan, Q M; Afzal, M

    2016-04-01

    Plants coupled with endophytic bacteria hold great potential for the remediation of polluted environment. The colonization patterns and activity of inoculated endophytes in rhizosphere and endosphere of host plant are among the primary factors that may influence the phytoremediation process. However, these colonization patterns and metabolic activity of the inoculated endophytes are in turn controlled by none other than the host plant itself. The present study aims to determine such an interaction specifically for plant-endophyte systems remediating crude oil-contaminated soil. A consortium (AP) of two oil-degrading endophytic bacteria (Acinetobacter sp. strain BRSI56 and Pseudomonas aeruginosa strain BRRI54) was inoculated to two grasses, Brachiaria mutica and Leptochloa fusca, vegetated in crude oil-contaminated soil. Colonization patterns and metabolic activity of the endophytes were monitored in the rhizosphere and endosphere of the plants. Bacterial augmentation enhanced plant growth and crude oil degradation. Maximum crude oil degradation (78%) was achieved with B. mutica plants inoculated with AP consortium. This degradation was significantly higher than those treatments, where plants and bacteria were used individually or L. fusca and endophytes were used in combination. Moreover, colonization and metabolic activity of the endophytes were higher in the rhizosphere and endosphere of B. mutica than L. fusca. The plant species affected not only colonization pattern and biofilm formation of the inoculated bacteria in the rhizosphere and endosphere of the host plant but also affected the expression of alkane hydroxylase gene, alkB. Hence, the investigation revealed that plant species can affect colonization patterns and metabolic activity of inoculated endophytic bacteria and ultimately the phytoremediation process.

  12. Evidence of Allopolyploidy in Urochloa humidicola Based on Cytological Analysis and Genetic Linkage Mapping.

    PubMed

    Vigna, Bianca B Z; Santos, Jean C S; Jungmann, Leticia; do Valle, Cacilda B; Mollinari, Marcelo; Pastina, Maria M; Pagliarini, Maria Suely; Garcia, Antonio A F; Souza, Anete P

    2016-01-01

    The African species Urochloa humidicola (Rendle) Morrone & Zuloaga (syn. Brachiaria humidicola (Rendle) Schweick.) is an important perennial forage grass found throughout the tropics. This species is polyploid, ranging from tetra to nonaploid, and apomictic, which makes genetic studies challenging; therefore, the number of currently available genetic resources is limited. The genomic architecture and evolution of U. humidicola and the molecular markers linked to apomixis were investigated in a full-sib F1 population obtained by crossing the sexual accession H031 and the apomictic cultivar U. humidicola cv. BRS Tupi, both of which are hexaploid. A simple sequence repeat (SSR)-based linkage map was constructed for the species from 102 polymorphic and specific SSR markers based on simplex and double-simplex markers. The map consisted of 49 linkage groups (LGs) and had a total length of 1702.82 cM, with 89 microsatellite loci and an average map density of 10.6 cM. Eight homology groups (HGs) were formed, comprising 22 LGs, and the other LGs remained ungrouped. The locus that controls apospory (apo-locus) was mapped in LG02 and was located 19.4 cM from the locus Bh027.c.D2. In the cytological analyses of some hybrids, bi- to hexavalents at diakinesis were observed, as well as two nucleoli in some meiocytes, smaller chromosomes with preferential allocation within the first metaphase plate and asynchronous chromosome migration to the poles during anaphase. The linkage map and the meiocyte analyses confirm previous reports of hybridization and suggest an allopolyploid origin of the hexaploid U. humidicola. This is the first linkage map of an Urochloa species, and it will be useful for future quantitative trait locus (QTL) analysis after saturation of the map and for genome assembly and evolutionary studies in Urochloa spp. Moreover, the results of the apomixis mapping are consistent with previous reports and confirm the need for additional studies to search for a co

  13. [Influence of three types of riparian vegetation on fluvial erosion control in Pantanos de Centla, Mexico].

    PubMed

    Sepúlveda-Lozada, Alejandra; Geissen, Violette; Ochoa-Gaona, Susana; Jarquín-Sánchez, Aarón; de la Cruz, Simón Hernández; Capetillo, Edward; Zamora-Cornelio, Luis Felipe

    2009-12-01

    Wetlands constitute very important ecological areas. The aim of this study was to quantify the soil losses due to fluvial erosion from 2006 to 2008 in two riverbanks under three types of vegetal coverage dominated by Haematoxylum campechianum, Dalbergia brownei and Brachiaria mutica, in the Pantanos de Centla Biosphere Reserve, SE Mexico. The relationship between the texture, organic matter and pH of soils and soil losses was evaluated. We used erosion sticks to estimate soil losses in 18 plots (three plots per type, three vegetation types, two riverbanks). Soil loss decreased in this order: H. campechianum>B. mutica>D. brownei indicating that D. brownei scrubland has the most potential to retain soil. The higher erosive impact within H. campechianum sites can be related with the low density of these trees in the study areas, as well as the lack of association with other types of vegetation that could reinforce the rooting of the soil profile. Furthermore, soil losses in H. campechianum sites were dependent on soil texture. The soils under this type of vegetal coverage were mainly sandy, which are more vulnerable to the erosive action in comparison with fine textured soils or soils with higher clay content, like the ones found in D. brownei and B. mutica sites. Soil losses of 100 % in the second year (B. mutica plots) can be attributed to the distribution of roots in the upper soil layer and also to livestock management along riverbanks. This study recognizes the importance of D. brownei scrublands in riverbank soil retention. Nevertheless it is necessary to consider the role of an entire vegetal community in future research.

  14. Carbon Isotope Discrimination in Forest and Pasture Ecosystems of the Amazon Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Ehleringer, J. R.; Ometto, J.; Ometto, J.; Flanagan, L. B.; Martinelli, L. A.; Moreira, M. Z.; Higuchi, N.

    2001-12-01

    Our objective was to measure the stable carbon isotope composition of leaf tissue and CO2 released by respiration (\\deltaR), and to use this information as an estimate of changes in ecosystem isotopic discrimination that occur in response to seasonal and interannual changes in environmental conditions, and land-use change (forest-pasture conversion). We made measurements in primary forest and pastures in the Amazon Basin of Brazil. At the Santarem forest site \\deltaR values showed a seasonal cycle varying from less than -29\\permil to approximately -26\\permil. The observed seasonal change in \\deltaR was correlated with variation in the average monthly precipitation. In contrast there was no significant seasonal variation in \\deltaR at the Manaus forest site (average δ _{R} approximately -28‰ ), consistent with a narrower range of variation in monthly precipitation than occurred in Santarem. Despite substantial (9‰ ) vertical variation in leaf δ ^{13}C, the average δ _{R} values observed for both forest sites were similar to the δ ^{13}C values of the most exposed, sun foliage of the dominant tree species. This suggested that the major portion of recently respired carbon dioxide in these forests was metabolized carbohydrate fixed by the sun leaves at the top of the forest canopy. There was no significant seasonal variation observed in the δ ^{13}C values of leaf organic matter for the forest sites. We sampled in pastures dominated by the C_{4} grass, Brachiaria spp., which is planted after forest vegetation has been cleared. The carbon isotope ratio of respired CO_{2} in pastures was enriched in ^{13}C by approximately 10‰ compared to forest ecosystems. A significant temporal change occurred in δ _{R} after the Manaus pasture was burned. Burning removed much of the encroaching C_{3} shrub vegetation and so allowed an increased dominance of the C_{4} pasture grass, which resulted in higher δ _{R}$ values.

  15. Transcriptome analysis of differentially expressed genes during embryo sac development in apomeiotic non-parthenogenetic interspecific hybrid of Pennisetum glaucum.

    PubMed

    Sahu, Pranav Pankaj; Gupta, Sarika; Malaviya, D R; Roy, Ajoy Kumar; Kaushal, Pankaj; Prasad, Manoj

    2012-07-01

    Apomixis results in the production of genetically uniform progeny, derived from the fertilization independent development (parthenogenesis) of an unreduced egg cell (apomeiosis). To identify genes involved in the apomeiosis, a comparative transcriptome analysis of differentially expressed genes during embryo sac (ES) development in a sexual Pennisetum glaucum (genotype 81A1) and its apomeiotic (aposporic) non-parthenogenetic interspecific hybrid (BC1GO) was investigated. BC1GO exhibited the partitioned apomeiosis component, whereby the second apomixis component viz., parthenogenesis was completely lacking. A total of 96 non-redundant transcripts were recovered using suppression subtractive hybridization and classified into 11 different categories according to their putative functions. Amongst the identified transcripts, many of them belonged to unknown function (40%) followed by those involved in protein metabolism, stress response, pollen/ovule/embryo development, and translation/protein modification process. A data search of transcriptional profiling in other apomictic species revealed that 75% of the differentially expressed transcripts have not been reported in previous studies. By macroarray analysis, we identified differential expression pattern of 96 transcripts, 45 (47%) of which showed ≥2-fold induction in apomeiotic BC1GO. Further, the obtained results were validated by quantitative real-time polymerase chain reaction to have a comparative expression profiling of eight selected up-regulated transcripts (≥2.5-fold) between BC1GO and 81A1 at different phases of ovule development. In silico mapping demonstrated that 13 transcripts were located onto rice chromosome 2, region syntenic with the apospory locus as reported in Brachiaria brizantha and Paspalum notatum. The expression patterns of these transcripts showed a significant difference at differentiating megaspore mother cell and gametogenesis stages thereby suggesting their involvement in floral

  16. Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil.

    PubMed

    Lammel, D R; Azevedo, L C B; Paula, A M; Armas, R D; Baretta, D; Cardoso, E J B N

    2015-11-01

    Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC), organic (OC) and integrated management systems containing intercropping of Brachiaria decumbens (IB) or Arachis pintoi (IA) were sampled. Total organic carbon (TOC), microbial biomass carbon (MBC) and nitrogen (MBN), microbial activity (C-CO2), metabolic quotient (qCO2), the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF) colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils) method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

  17. Changes in nutrient dynamics throughout water transfers in a Tropical Forest and Pasture of Rondonia, Brazil

    NASA Astrophysics Data System (ADS)

    Piccolo, M. D.; Neill, C.; Krusche, A.; Laclau, J. P.; Cerri, C. C.

    2006-12-01

    The clearing of tropical forest in the Brazilian Amazon for cattle pasture since the 70s is a globally important land use change that has consequences for soil biogeochemical cycles. Generally, five to ten years after deforestation, pastures become degraded due to inadequate management practices. Development of strategies for restoration of low productivity pastures constitutes the main goal for Rondônia state. We analyzed the concentrations of the main nutrient of the biogeochemical cycles in three representative land uses at Fazenda Nova Vida, in central Rondônia (10o30'S, 62o30'W). The treatments were: (1) native forest; (2) pasture dominated by the forage grass Brachiaria brizantha but containing some weeds, under non- intensive management and; (3) a section of the same pasture that was subjected to tilling, replanting and fertilization (NPK + micronutrients) to eliminate weeds and improve grass productivity. Water samples from rain, throughfall, overland flow, tension lysimeter and zero-tension lysimeter (1.0 m soil depth), were collected during the rainy seasons from January to May of 2002 and 2003. The concentrations of C (DOC and DIC), inorganic-N (NH4+, NO3- and NO2-), Na+, K+, Mg2+, Ca2+, SO42- and Cl- were measured in all treatments. Rain water was dominated by the nutrients (NH4+, Na+, K+, Ca2+ and Cl-) and DOC. Forest throughfall was enriched in most of the elements. Concentrations of elements in the overland flow showed higher variations in the pasture and in the plowed pasture, however samples were not collected in forest. Soil solution waters (tension lysimeter) and lysimeter waters (zero-tension lysimeter) too had higher variations for elements concentrations in all treatments. Forest clearing for pasture and pasture submitted to tillage practices profoundly influence soil properties and, consequently, the nutrient availability in soil profiles. The soil solution composition may be indicative of altered patterns of nutrient availability in this

  18. Bio-concentration of chromium--an in situ phytoremediation study at South Kaliapani chromite mining area of Orissa, India.

    PubMed

    Mohanty, Monalisa; Pattnaik, Mausumi M; Mishra, Aruna K; Patra, Hemanta K

    2012-01-01

    Mine waste water at South Kaliapani usually contains toxic levels of hexavalent Cr(VI). The present in situ study was conducted at South Kaliapani chromite mine area in Orissa state, India, to assess the phytoremediation ability of three plants, namely, rice (Oryza sativa L.), paragrass (Brachiaria mutica), and an aquatic weed (Eichhornia crassipes), in attenuating Cr(VI) from mine waste water and to correlate the bio-concentration factors (BCF) of Cr. Water hyacinth (E. crassipes) showed 24% to 54% reduction whereas paragrass (B. mutica) was able to reduce 18% to 33% of Cr(VI) from mine water. This reduction was studied over a period of 100 days of plant growth. The reduction was observed through a passage of a sum total of 2,000 sq. ft. cultivated plots and ponds separately. Reduction in Cr(VI) content in mine water varies with plant age as well as with the distance of passage. Cr accumulation and BCF values increased with high soil Cr levels as well as the age of plants. High BCF and transportation index (Ti) values, i.e., 10,924 and 32.09, respectively, were noted for water hyacinth. The Ti values indicated that the root-to-shoot translocation of Cr was very high after 100 days of growth. The total accumulation rate was maximum (8.29 mg Cr kg dry biomass(-1) day (-1)) in paragrass. The BCF values for roots were noted to be higher than those of leaves, stems, and grains of the 125-day-old plants. Hence, paragrass and water hyacinth may be used as tools of phytoremediation to combat the problem of in situ Cr contamination.

  19. Feed Intake, Digestibility, and N Retention in Cattle Fed Rice Straw and Para Grass Combined with Different Levels of Protein Derived from Cassava Foliage

    PubMed Central

    Sath, K.; Sokun, K.; Pauly, T.; Holtenius, K.

    2012-01-01

    Eight male cattle of Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava foliage supplementation (Manihot esculenta) on intake, digestibility and N retention. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a 4×4 double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cattle selected cassava leaves in preference to petioles. Petiole intake decreased from 64 to 48% of offered petioles when the cassava foliage proportion increased from the lowest to the highest level. The cattle consumed all the leaves at the two lower levels of cassava foliage inclusion and 91% at the highest level. Rice straw intake decreased significantly as the level of cassava foliage increased. Intake of DM, OM, NDF, and ADF increased significantly with increasing intake of cassava foliage. Daily DM intake per 100 kg BW increased from 2.7 to 3.2 kg with increasing cassava foliage intake. No effect on CP digestibility was detected when the level of cassava foliage increased. Digestibility of DM, OM, NDF and ADF was significantly higher in the group fed no cassava foliage than in the other groups. N retention increased from 16 to 28 g/d with the first level of cassava foliage inclusion, but levelled out at the two highest levels. N excretion increased in both faeces and urine as a response to higher intake of cassava foliage. Maximum N retention occurred when 40% of total N intake came from cassava foliage (equivalent to 1.3 g CP/kg BW). PMID:25049650

  20. Achieving food security for one million sub-Saharan African poor through push-pull innovation by 2020.

    PubMed

    Khan, Zeyaur R; Midega, Charles A O; Pittchar, Jimmy O; Murage, Alice W; Birkett, Michael A; Bruce, Toby J A; Pickett, John A

    2014-04-05

    Food insecurity is a chronic problem in Africa and is likely to worsen with climate change and population growth. It is largely due to poor yields of the cereal crops caused by factors including stemborer pests, striga weeds and degraded soils. A platform technology, 'push-pull', based on locally available companion plants, effectively addresses these constraints resulting in substantial grain yield increases. It involves intercropping cereal crops with a forage legume, desmodium, and planting Napier grass as a border crop. Desmodium repels stemborer moths (push), and attracts their natural enemies, while Napier grass attracts them (pull). Desmodium is very effective in suppressing striga weed while improving soil fertility through nitrogen fixation and improved organic matter content. Both companion plants provide high-value animal fodder, facilitating milk production and diversifying farmers' income sources. To extend these benefits to drier areas and ensure long-term sustainability of the technology in view of climate change, drought-tolerant trap and intercrop plants are being identified. Studies show that the locally commercial brachiaria cv mulato (trap crop) and greenleaf desmodium (intercrop) can tolerate long droughts. New on-farm field trials show that using these two companion crops in adapted push-pull technology provides effective control of stemborers and striga weeds, resulting in significant grain yield increases. Effective multi-level partnerships have been established with national agricultural research and extension systems, non-governmental organizations and other stakeholders to enhance dissemination of the technology with a goal of reaching one million farm households in the region by 2020. These will be supported by an efficient desmodium seed production and distribution system in eastern Africa, relevant policies and stakeholder training and capacity development.

  1. Cover cropping alters the diet of arthropods in a banana plantation: a metabarcoding approach.

    PubMed

    Mollot, Gregory; Duyck, Pierre-François; Lefeuvre, Pierre; Lescourret, Françoise; Martin, Jean-François; Piry, Sylvain; Canard, Elsa; Tixier, Philippe

    2014-01-01

    Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey.

  2. Cover Cropping Alters the Diet of Arthropods in a Banana Plantation: A Metabarcoding Approach

    PubMed Central

    Mollot, Gregory; Duyck, Pierre-François; Lefeuvre, Pierre; Lescourret, Françoise; Martin, Jean-François; Piry, Sylvain; Canard, Elsa; Tixier, Philippe

    2014-01-01

    Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey. PMID:24695585

  3. Achieving food security for one million sub-Saharan African poor through push–pull innovation by 2020

    PubMed Central

    Khan, Zeyaur R.; Midega, Charles A. O.; Pittchar, Jimmy O.; Murage, Alice W.; Birkett, Michael A.; Bruce, Toby J. A.; Pickett, John A.

    2014-01-01

    Food insecurity is a chronic problem in Africa and is likely to worsen with climate change and population growth. It is largely due to poor yields of the cereal crops caused by factors including stemborer pests, striga weeds and degraded soils. A platform technology, ‘push–pull’, based on locally available companion plants, effectively addresses these constraints resulting in substantial grain yield increases. It involves intercropping cereal crops with a forage legume, desmodium, and planting Napier grass as a border crop. Desmodium repels stemborer moths (push), and attracts their natural enemies, while Napier grass attracts them (pull). Desmodium is very effective in suppressing striga weed while improving soil fertility through nitrogen fixation and improved organic matter content. Both companion plants provide high-value animal fodder, facilitating milk production and diversifying farmers’ income sources. To extend these benefits to drier areas and ensure long-term sustainability of the technology in view of climate change, drought-tolerant trap and intercrop plants are being identified. Studies show that the locally commercial brachiaria cv mulato (trap crop) and greenleaf desmodium (intercrop) can tolerate long droughts. New on-farm field trials show that using these two companion crops in adapted push–pull technology provides effective control of stemborers and striga weeds, resulting in significant grain yield increases. Effective multi-level partnerships have been established with national agricultural research and extension systems, non-governmental organizations and other stakeholders to enhance dissemination of the technology with a goal of reaching one million farm households in the region by 2020. These will be supported by an efficient desmodium seed production and distribution system in eastern Africa, relevant policies and stakeholder training and capacity development. PMID:24535391

  4. Effect of supplementation of beef cattle with different protein levels and degradation rates during transition from the dry to rainy season.

    PubMed

    Fernandes, Rodolfo Maciel; de Almeida, Chafic Mustafé; Carvalho, Bruna Caldas; Alves Neto, João Alexandrino; Mota, Verônica Aparecida Costa; de Resende, Flávio Dutra; Siqueira, Gustavo Rezende

    2016-01-01

    The objective of this study was to evaluate the effect of increasing the supply of protein with different degradation rates on the performance and metabolism of growing Nellore cattle reared on Brachiaria brizantha cv. Marandu pasture during the transition period from the dry to rainy season. The experiment was installed on an area of 34 ha, divided into 12 paddocks with an average area of 2.85 ha. In the performance evaluation were utilized 72 recently weaned, non-castrated Nellore cattle with an initial body weight (BW) of 199 kg (SEM = 16). The following supplements were used: energy protein supplement containing 25% crude protein (CP) (C-25) and energy protein supplements containing 40% CP with one third highly degradable CP and two thirds poorly degradable CP (40-1/3NPN), one half highly degradable CP and one half poorly degradable CP (40-1/2NPN), and two thirds highly degradable CP and one third poorly degradable CP (40-2/3NPN). Higher protein degradation rates reduced supplement intake (P < 0.01). In the first period, animals consuming supplement 40-1/3NPN exhibited higher average daily gain (ADG) (0.30 kg/day), similar to that of animals receiving supplement 40-1/2NPN (P = 0.04). In the second period, supplement 40-2/3NPN resulted in lower ADG (0.19 kg/day less than the other supplements). There was no effect of supplement on animal performance in the third period (P > 0.10), when ADG was 0.56 kg/day. In conclusion, the response to supplementation is associated with interactions with characteristics of the forage canopy. Supplementation with a true protein source will be beneficial only during the early stage of the dry-rainy season transition period.

  5. Soil, water, and nutrient losses from management alternatives for degraded pasture in Brazilian Atlantic Rainforest biome.

    PubMed

    Rocha Junior, Paulo Roberto da; Andrade, Felipe Vaz; Mendonça, Eduardo de Sá; Donagemma, Guilherme Kangussú; Fernandes, Raphael Bragança Alves; Bhattharai, Rabin; Kalita, Prasanta Kumar

    2017-04-01

    The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha(-1)) and BUR (5.20tha(-1)) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (p<0.05). Our findings indicated that the traditional pasture management adopted in the Atlantic Rainforest needs to be rethought and burned management should be avoided. Based on the water, soil, and nutrient losses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome.

  6. Herbarium of the University of Malaga (Spain): Vascular Plants Collection

    PubMed Central

    García-Sánchez, José; Cabezudo, Baltasar

    2013-01-01

    Abstract The herbarium of University of Málaga (MGC Herbarium) is formed by four biological collections. The vascular plants collection (MGC-Cormof) is the main collection of the herbarium. MGC-Cormof dataset aims to digitize and publish data associated with over 76.000 specimens deposited in the collection, of which 97.2% of the specimens are identified at species level. Since 2011, the University of Malaga’s Central Research Service (SCAI) has been responsible for maintaining the herbariums and the dataset. The collection is growing continuously, with an annual intake of about 1.500 specimens. Nearly 96% of the collection is digitized, by Herbar v3.7.1 software (F. Pando et al. 1996–2011), making over 73.000 specimens accessible through the GBIF network (http://data.gbif.org/datasets/resource/8105/). At present, 247 families and 8.110 taxa, distributed in angiosperms (93.97%), ferns and fern allies (4.89%) and gymnosperms (1.14%), constitute the MGC-Cormof collection. The families and genera best represented in the collection are Compositae, Leguminosae, Gramineae, Labiatae, Caryophyllaceae, Teucrium, Silene, Asplenium, Linaria and Quercus. Most of the specimens are from the Western Mediterranean Region, fundamentally Southern Spain (Andalusia: 82% of specimens) and Northern Morocco (2.17%). Approximately, 63% of the specimens are georeferenced. The identification of the specimens in the collection has been carried out by the plant biology department at the University of Malaga and plus 40% of the specimens has been reviewed by experts. The MGC-Cormof dataset has been revised by DarwinTest v3.2 tool (Ortega-Maqueda and Pando 2008) before being published in GBIF. The data included in this database are important for conservation works, taxonomy, flora, cartography, phenology, palynology, among others. El Herbario de la Universidad de Málaga (Herbario MGC) está constituido por cuatro colecciones biológicas. La colección de plantas vasculares (MGC Cormof) es

  7. Herbarium of the university of malaga (Spain): vascular plants collection.

    PubMed

    García-Sánchez, José; Cabezudo, Baltasar

    2013-01-01

    The herbarium of University of Málaga (MGC Herbarium) is formed by four biological collections. The vascular plants collection (MGC-Cormof) is the main collection of the herbarium. MGC-Cormof dataset aims to digitize and publish data associated with over 76.000 specimens deposited in the collection, of which 97.2% of the specimens are identified at species level. Since 2011, the University of Malaga's Central Research Service (SCAI) has been responsible for maintaining the herbariums and the dataset. The collection is growing continuously, with an annual intake of about 1.500 specimens. Nearly 96% of the collection is digitized, by Herbar v3.7.1 software (F. Pando et al. 1996-2011), making over 73.000 specimens accessible through the GBIF network (http://data.gbif.org/datasets/resource/8105/). At present, 247 families and 8.110 taxa, distributed in angiosperms (93.97%), ferns and fern allies (4.89%) and gymnosperms (1.14%), constitute the MGC-Cormof collection. The families and genera best represented in the collection are Compositae, Leguminosae, Gramineae, Labiatae, Caryophyllaceae, Teucrium, Silene, Asplenium, Linaria and Quercus. Most of the specimens are from the Western Mediterranean Region, fundamentally Southern Spain (Andalusia: 82% of specimens) and Northern Morocco (2.17%). Approximately, 63% of the specimens are georeferenced. The identification of the specimens in the collection has been carried out by the plant biology department at the University of Malaga and plus 40% of the specimens has been reviewed by experts. The MGC-Cormof dataset has been revised by DarwinTest v3.2 tool (Ortega-Maqueda and Pando 2008) before being published in GBIF. The data included in this database are important for conservation works, taxonomy, flora, cartography, phenology, palynology, among others. El Herbario de la Universidad de Málaga (Herbario MGC) está constituido por cuatro colecciones biológicas. La colección de plantas vasculares (MGC Cormof) es la colecci

  8. Evaluating the composition and processing potential of novel sources of Brazilian biomass for sustainable biorenewables production

    PubMed Central

    2014-01-01

    Background The search for promising and renewable sources of carbohydrates for the production of biofuels and other biorenewables has been stimulated by an increase in global energy demand in the face of growing concern over greenhouse gas emissions and fuel security. In particular, interest has focused on non-food lignocellulosic biomass as a potential source of abundant and sustainable feedstock for biorefineries. Here we investigate the potential of three Brazilian grasses (Panicum maximum, Pennisetum purpureum and Brachiaria brizantha), as well as bark residues from the harvesting of two commercial Eucalyptus clones (E. grandis and E. grandis x urophylla) for biofuel production, and compare these to sugarcane bagasse. The effects of hot water, acid, alkaline and sulfite pretreatments (at increasing temperatures) on the chemical composition, morphology and saccharification yields of these different biomass types were evaluated. Results The average yield (per hectare), availability and general composition of all five biomasses were compared. Compositional analyses indicate a high level of hemicellulose and lignin removal in all grass varieties (including sugarcane bagasse) after acid and alkaline pretreatment with increasing temperatures, whilst the biomasses pretreated with hot water or sulfite showed little variation from the control. For all biomasses, higher cellulose enrichment resulted from treatment with sodium hydroxide at 130°C. At 180°C, a decrease in cellulose content was observed, which is associated with high amorphous cellulose removal and 5-hydroxymethyl-furaldehyde production. Morphological analysis showed the effects of different pretreatments on the biomass surface, revealing a high production of microfibrillated cellulose on grass surfaces, after treatment with 1% sodium hydroxide at 130°C for 30 minutes. This may explain the higher hydrolysis yields resulting from these pretreatments, since these cellulosic nanoparticles can be easily

  9. Structural quality of on Oxisol in recovery for 18 years

    NASA Astrophysics Data System (ADS)

    dos Santos Batista Bonini, C.; Alves, M. C.; Marchini, D. C.; Garcia de Arruda, O.; Nilce Souto Filho, S.

    2012-04-01

    Incorrect use of soil and large buildings construction in rural areas are causing changes to it, making them less productive and thus increasing the degraded areas. Techniques aimed at ecological restoration of degraded soils have been investigated. In this sense we investigated the positive changes in the structural quality of a soil that was beheaded in human intervention techniques for recovery for 18 years, having been used green manures, gypsum and pasture. The studied area is located in Mato Grosso do Sul, Brazil. The experimental design was a completely randomized with seven treatments and four replications. The treatments were: control (tilled soil without culture); Stizolobium aterrium; Cajanus cajan; lime+S. aterrimum; lime+C. cajan; lime+gypsum+S. aterrimum; lime+gypsum+C. cajan. In 1994, all treatments with C. cajan were replaced by Canavalia ensiformis and in 1999, Brachiaria decumbens was implanted in all treatments. Data from vegetated treatments were compared with the control bare soil and native vegetation (savannah). We evaluated the distribution and aggregate stability in water, soil samples were collected in 2010 in the depths: 0.00-0.10; 0.10-0.20 and 0,20-0.40 m. The results were analyzed by analysis of variance, following Scott-Knott test (5%) of probability to compare averages. Evaluating the results is noted that in the depth of 0.00-0.10 m, the control bare soil and savannah soil had lower and higher DMP, respectively. All recovery treatments were DMP greater than found for the bare soil control. Treatments: S. aterrimum, lime + gypsum + C. cajan and lime + gypsum + S. aterrimum and the savannah control were similar in the depth of 0.00-0.10 m. All of the recovery treatment in the depth from 0.00-0.10 m with values is close to the native vegetation of the savannah. Depths of 0.10-0.20 and 0.20-0.40 m results obtained for DMP treatments in recovery are similar to the bare soil, except for treatments with S. aterrimum and lime + gypsum + S

  10. Greenhouse gas emission from cattle urine deposition in pasture under tropical conditions.

    NASA Astrophysics Data System (ADS)

    Mancebo Mazzetto, Andre; Simões Barneze, Arlete; Josefine Feigl, Brigitte; Clemente Cerri, Carlos; Willem van Groenigen, Jan

    2014-05-01

    Animal production systems are important sources of greenhouse gases (GHG), especially methane (CH4) and nitrous oxide (N2O). Brazilian beef production is almost exclusively (more than 90%) pasture-based, and most GHG emissions from this system originate from urine patches. GHG emissions from urine patches have been extensively studied in temperate climates, but not for tropical conditions. Here we examined the driving factors of N2O emission from urine patches (U treatment) in the tropics, as well as the role of the nitrification inhibitor DCD (dicyandiamide - U+DCD treatment) in mitigating emissions. We measured the emission of CH4 and N2O from beef cattle urine (360 kg N ha-1) in Rondônia state (Brazil, tropical climate), during two different seasons (winter and summer), with and without the application of DCD (10 kg ha-1). We hypothesized that the high temperature and periodical rainfall can decrease GHG emissions from urine patches through accelerating mineralization of urine-N. The cumulative emissions during winter were 10.8 and 39.2 mg N-N2O m-2 (U and U+DCD treatment, respectively), and 126.2 and 129.5 mg N-N2O m-2 during summer (U and U+DCD treatment, respectively). No effects of DCD were detected in summer, but DCD retarded the main peak of N2O emission. Otherwise, during winter U+DCD treatment had the higher cumulative N2O emission (p≤0.05). The emission factors determined were 0.08 and 0.13% (winter U and U+DCD, respectively) and 0.38 and 0.37% (summer U and U+DCD, respectively), significantly lower than the IPCC default value of 1%. We hypothesize that biological nitrification inhibition (BNI) is the main reason for such low emission factors, since Brachiaria grasses naturally inhibits the nitrification process. In this situation the use of DCD is not recommended. The fast decomposition of DCD in warmer climates leads to a short-term effect in nitrification inhibition. The excess of N due to DCD decomposition can trigger a priming-effect, increasing

  11. Chemical, green and organic manure effects on chemical properties on a savannah oxisol and on corn under conventional tillage and no-tillage

    NASA Astrophysics Data System (ADS)

    Mannigel, Anny R.; Alves, Marlene C.; Valério Filho, Walter V.

    2015-04-01

    Modern agriculture, in general, has always been based on the concept that natural resources are endless; however, this concept is changing. Concern for the environment is increasingly becoming part of farming practices, either by the awareness of society, or because the high cost of fertilizers or even the exhaustion of soils. The objective of this research was to evaluate the effects of the green manure and mineral fertilizer and/or organic manure and, on the chemical properties of an Oxisol, on "Savannah" (cerrado) area in Mato Grosso do Sul-Brazil, cultivated with corn (Zea mays L.) on the following management conditions: no-tillage and conventional tillage, on area previously under pasture (Brachiaria decumbens). The experimental design was a randomized blocks and the tested treatments were: control (without organic manure or chemical fertilizer); chemical fertilizer, as recommended for the culture and based on the chemical soil analysis; organic manure (cow manure); organic manure + half of the mineral fertilizer recommended rate; and the green manure Crotalaria juncea and Pennisetum americanum. The chemical analyses were the soil chemical analysis to the intent of soil fertility. Corn yield was evaluated. The collect of soil samples were realized in depths of 0.00-0.05 m and 0.05-0.10 m and 0.10-0.20 m. The organic manure and the organic manure + half of the mineral recommended rate increased P, Ca, Mg, K and Organic Matter in the first depth (0.00 - 0.05 m). These treatments also increased K and Mg at the second depth analyzed (0.05 - 0.10 m) and K in the depth from 0.10 - 0.20 m. Under conventional tillage management presents better crop results with an average grain yield of 3649 kg ha-1 versus 2374 kg ha-1 obtained under no-tillage. The use of chemical fertilizer, organic manure + half of the mineral recommended rate, Crotalaria juncea, organic manure and Pennisetum americanum increased corn yield by 84, 79, 58, 44 and 41 %, respectively.

  12. Effectiveness of Biomass Harvesting from Stormwater Detention Areas in Reducing Phosphorus Discharges

    NASA Astrophysics Data System (ADS)

    Shukla, A.; Shukla, S.

    2014-12-01

    Stormwater Detention Areas (SDAs) in agricultural landscapes are considered to be the most important Best Management Practice by state agencies in Florida. Two main processes responsible for Phosphorus (P) retention in SDAs are soil adsorption and plant uptake. Long term pumping of agricultural drainage may saturate the SDA's soil with P which can put these systems at the risk of becoming a source of P. Given that these systems already occupy part of the farmland and are costly to build, interventions are needed to sustain SDAs as a sink of P. Soil and vegetation P content at two SDAs (SDA1 and 2) in south Florida was quantified in addition to inflow and outflow P loads. Analyses showed that soil was saturated with limited to no P adsorption capacity remaining. Negative Soil Phosphorus Storage Capacity (SPSC) indicated that soil was at a risk of P release. Given these conditions, the only avenue to remove P from SDAs without any potentially undesirable ecological impacts, was biomass harvesting. At SDA1, results showed that harvesting the aboveground biomass would result in 19% extra P retention if the current vegetation (Para grass, Brachiaria mutica) is harvested. Given that aboveground tissue P content of Para grass is very low, replacing it with another native grass (Maidencane, Panicum hemitomon) and harvesting it annually could retain most of the incoming P load. A similar analysis showed that at SDA2, almost 40% additional P could be retained by harvesting aboveground biomass of the dominant vegetation (Torpedo Grass, Panicum repens and Smartweed, Polygonum hydropiperoides). A spatial analysis in conjunction with SPSC values and aboveground plant P indicated that biomass harvesting can transform both the SDAs from a source to sink in 2 to 3 years. A fifty year net present value analysis showed that overall it is an economically feasible strategy with an average annual benefit of 3,223 and 34,825 for SDA1 and 2, respectively. Harvesting aboveground biomass

  13. Arbuscular mycorrhizal fungal communities in sub-Saharan savannas of Benin, West Africa, as affected by agricultural land use intensity and ecological zone.

    PubMed

    Tchabi, Atti; Coyne, Danny; Hountondji, Fabien; Lawouin, Louis; Wiemken, Andres; Oehl, Fritz

    2008-04-01

    The rapid decline of soil fertility of cultivated lands in the sub-Saharan savannas of West Africa is considered to be the main cause of the increasingly severe constraints of food production. The soils in this tropical area are highly fragile, and crop yields are limited by characteristically low levels of available phosphorus. Under such preconditions, the multiple benefits of the arbuscular mycorrhizal (AM) symbiosis are likely to play a pivotal role for maintaining natural soil fertility by enhancing plant nutrient use efficiency, plant health, and stabilization of a favorable soil structure. Thus, it is important to explore the impact of the commonly applied farming practices on the native AM fungal community. In the present study, we determined the AM fungal species composition in three ecological zones differing by an increasingly prolonged dry season from South to North, from the Southern Guinea Savanna (SG), to the Northern Guinea Savanna (NG), to the Sudan Savanna (SU). In each zone, four "natural" and four "cultivated" sites were selected. "Natural" sites were three natural forest savannas (at least 25-30 years old) and a long-term fallow (6-7 years old). "Cultivated" sites comprised a field with yam (Dioscorea spp.) established during the first year after forest clearance, a field under mixed cropping with maize (Zea mays) and peanut (Arachis hypogaea), a field under peanut, and a field under cotton (Gossypium hirsutum) which was the most intensively managed crop. Soil samples were collected towards the end of the wet season in each zone. AM fungal spores were extracted and morphologically identified. Soil subsamples were used to inoculate AM fungal trap cultures using Stylosanthes guianensis and Brachiaria humidicola as host plants to monitor AM root colonization and spore formation over 10 and 24 months, respectively. A total of 60 AM fungal species were detected, with only seven species sporulating in the trap cultures. Spore density and species

  14. Isotopic ((13)C) fractionation during plant residue decomposition and its implications for soil organic matter studies.

    PubMed

    Schweizer; Fear; Cadisch

    1999-07-01

    Carbon isotopic fractionations in plant materials and those occurring during decomposition have direct implications in studies of short-and longer-term soil organic matter dynamics. Thus the products of decomposition, the evolved CO(2) and the newly formed soil organic matter, may vary in their (13)C signature from that of the original plant material. To evaluate the importance of such fractionation processes, the variations in (13)C signatures between and within plant parts of a tropical grass (Brachiaria humidicola) and tropical legume (Desmodium ovalifolium) were measured and the changes in (13)C content (signatures) during decomposition were monitored over a period of four months. As expected the grass materials were less depleted in (13)C (-11.4 to -11.9 per thousand) than those of the legume (-27.3 to -25.8 per thousand). Root materials of the legume were less (1.5 per thousand) depleted in (13)C compared with the leaves. Plant lignin-C was strongly depleted in (13)C compared with the bulk material by up to 2.5 per thousand in the legume and up to 4.7 per thousand in the grass. Plant materials were subsequently incubated in a sand/nutrient-solution/microbial inoculum mixture. The respiration product CO(2) was trapped in NaOH and precipitated as CaCO(3), suitable for analysis using an automated C/N analyser coupled to an isotope ratio mass spectrometer. Significant depletion in (13)C of the evolved CO(2) was observed during the initial stages of decomposition probably as a result of microbial fractionation as it was not associated with the (13)C signatures of the measured more decomposable fractions (non-acid detergent fibre and cellulose). While the cumulative CO(2)-(13)C signatures of legume materials became slightly enriched with ongoing decomposition, the CO(2)-C of the grass materials remained depleted in (13)C. Associated isotopic fractionation correction factors for source identification of CO(2-)C varied with time and suggested errors of 2-19% in the

  15. The requirements for rumen-degradable protein per unit of fermentable organic matter differ between fibrous feed sources

    PubMed Central

    Soliva, Carla R.; Amelchanka, Sergej L.; Kreuzer, Michael

    2015-01-01

    Ruminant feed evaluation systems use constant minimum requirements of rumen-degradable protein (RDP) and often relate this to apparently degradable organic matter (OM). However, studies with tropical forages indicate that RDP: apparently degraded OM might not be constant across high-fiber diets. This was tested with semi-continuous ruminal cultures (Rusitec) using dried contrasting low-protein fiber sources: brachiaria hay (high in fiber, medium lignified), apple pomace (medium in fiber, highly lignified), and sugar beet pulp (medium in fiber and lignification). Each feed was incubated at 14 g dry matter day−1 with 0, 0.85, 1.7, 3.4, 6.8, 13.6, or 27.2 mg g−1 urea. The amount of urea needed to reach a similar basal concentration of ammonia in the incubation fluid was tested for each feed in advance. Apparent fiber and OM degradability were determined after 48 h of incubation. Data was evaluated by regressions and analysis of variance. The response curve of incubation fluid ammonia to urea supplementation was similar in slope in all feeds. Plateaus in apparent OM degradability in relation to ammonia concentration were determined. The ammonia concentration where apparent OM and fiber degradability reached 95% of maximum was approached in the order of pomace < pulp < hay. With regard to fiber degradability, a plateau was reached at ≥ 80 g kg−1 crude protein only with hay and pomace, whilst a linear relationship existed between RDP and OM degradation for pulp. In hay the ratio RDP: OM degraded was equal to 1.6 but was only 1.0 in the other feeds. There was no obvious lack of branched short-chain fatty acids at low RDP. Thus, the hypothesis was confirmed but the demand for RDP seems even higher in tropical forage compared to food industrial byproducts. The efficiency of urea to promote apparent OM and fiber degradation was also variable. Thus, it seems that minimum thresholds of either RDP or ruminal ammonia concentration may not be reflected appropriately by

  16. Carbon isotope discrimination in forest and pasture ecosystems of the Amazon Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Ometto, Jean P. H. B.; Flanagan, Lawrence B.; Martinelli, Luiz A.; Moreira, Marcelo Z.; Higuchi, Niro; Ehleringer, James R.

    2002-12-01

    Our objective was to measure the stable carbon isotope composition of leaf tissue and CO2 released by respiration (δr), and to use this information as an estimate of changes in ecosystem isotopic discrimination that occur in response to seasonal and interannual changes in environmental conditions, and land-use change (forest-pasture conversion). We made measurements in primary forest and pastures in the Amazon Basin of Brazil. At the Santarém forest site, δr values showed a seasonal cycle varying from less than -29‰ to approximately -26‰. The observed seasonal change in δr was correlated with variation in the observed monthly precipitation. In contrast, there was no significant seasonal variation in δr at the Manaus forest site (average δr approximately -28‰), consistent with a narrower range of variation in monthly precipitation than occurred in Santarém. Despite substantial (9‰) vertical variation in leaf δ13C, the average δr values observed for all forest sites were similar to the δ13C values of the most exposed sun foliage of the dominant tree species. This suggested that the major portion of recently respired carbon dioxide in these forests was metabolized carbohydrate fixed by the sun leaves at the top of the forest canopy. There was no significant seasonal variation observed in the δ13C values of leaf organic matter for the forest sites. We sampled in pastures dominated by the C4 grass, Brachiaria spp., which is planted after forest vegetation has been cleared. The carbon isotope ratio of respired CO2 in pastures was enriched in 13C by approximately 10‰ compared to forest ecosystems. A significant temporal change occurred in δr after the Manaus pasture was burned. Burning removed much of the encroaching C3 shrub vegetation and so allowed an increased dominance of the C4 pasture grass, which resulted in higher δr values.

  17. Mineral Status in Cattle Fed Rice Straw and Para Grass Combined with Different Levels of Protein Derived from Cassava Foliage

    PubMed Central

    Sath, K.; Pauly, T.; Holtenius, K.

    2013-01-01

    Eight male cattle of the Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava (Manihot esculenta) foliage supplementation on mineral metabolism in growing cattle fed rice straw and para grass as basal diet. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a 4×4 double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cassava foliage intake was lower than the planned levels. DM consumption was significantly affected by cassava foliage supplementation, with the largest intake observed at the two highest levels of cassava foliage supplementation. Rice straw intake showed the opposite pattern, with lower intake at higher cassava foliage supplementation. No refusals occurred for para grass in any of the treatments. Ca, P, Mg, K, S and Mn intake increased significantly with increasing intake of cassava foliage, but Na intake was not affected by treatment. Faecal excretion of Ca, Mg, S and Mn increased significantly with increasing cassava foliage intake. There were no differences between P, K and Na excretion in faeces. There was a significant diet effect on Mg, S and Mn digestibility. Mg and Mn digestibility increased with increasing cassava foliage supplementation, while S digestibility decreased. Ca, P, K and Na digestibility was not affected by diet. There was a significant effect of treatment on P retention, with the highest value observed for supplementation with 1.6 g CP/kg BW cassava foliage. Ca and Mg showed similar trends, with the highest retention again for supplementation with 1.6 g CP/kg BW cassava foliage. There were weak but significant positive correlations between nitrogen retention and the macro minerals Ca, P and Mg. Furthermore, retention of all these minerals was positively correlated. Mineral losses in urine were not affected

  18. Evidence of Allopolyploidy in Urochloa humidicola Based on Cytological Analysis and Genetic Linkage Mapping

    PubMed Central

    Vigna, Bianca B. Z.; Santos, Jean C. S.; Jungmann, Leticia; do Valle, Cacilda B.; Mollinari, Marcelo; Pastina, Maria M.; Garcia, Antonio A. F.

    2016-01-01

    The African species Urochloa humidicola (Rendle) Morrone & Zuloaga (syn. Brachiaria humidicola (Rendle) Schweick.) is an important perennial forage grass found throughout the tropics. This species is polyploid, ranging from tetra to nonaploid, and apomictic, which makes genetic studies challenging; therefore, the number of currently available genetic resources is limited. The genomic architecture and evolution of U. humidicola and the molecular markers linked to apomixis were investigated in a full-sib F1 population obtained by crossing the sexual accession H031 and the apomictic cultivar U. humidicola cv. BRS Tupi, both of which are hexaploid. A simple sequence repeat (SSR)-based linkage map was constructed for the species from 102 polymorphic and specific SSR markers based on simplex and double-simplex markers. The map consisted of 49 linkage groups (LGs) and had a total length of 1702.82 cM, with 89 microsatellite loci and an average map density of 10.6 cM. Eight homology groups (HGs) were formed, comprising 22 LGs, and the other LGs remained ungrouped. The locus that controls apospory (apo-locus) was mapped in LG02 and was located 19.4 cM from the locus Bh027.c.D2. In the cytological analyses of some hybrids, bi- to hexavalents at diakinesis were observed, as well as two nucleoli in some meiocytes, smaller chromosomes with preferential allocation within the first metaphase plate and asynchronous chromosome migration to the poles during anaphase. The linkage map and the meiocyte analyses confirm previous reports of hybridization and suggest an allopolyploid origin of the hexaploid U. humidicola. This is the first linkage map of an Urochloa species, and it will be useful for future quantitative trait locus (QTL) analysis after saturation of the map and for genome assembly and evolutionary studies in Urochloa spp. Moreover, the results of the apomixis mapping are consistent with previous reports and confirm the need for additional studies to search for a co

  19. - and Cross-Polarization 13C NMR Evidence of Alterations in Molecular Composition of Humic Substances Following Afforestation with Eucalypt in Distinct Brazilian Biomes

    NASA Astrophysics Data System (ADS)

    Silva, I. R.; Soares, E. M.; Schmidt-Rohr, K.; Novais, R.; Barros, N.; Fernandes, S.

    2010-12-01

    The effect of planting fast growing tree species on SOM quality in tropical regions has been overlooked. In the present study 13C-NMR approaches were used to evaluate the impact of eucalypt cultivation on humic and fulvic acids molecular composition. The results indicate that the replacement of native vegetation by eucalypt plantations increased the relative contribution of aliphatic groups in HA from soils previously under Atlantic Forest, Grassland, and the Cerrado (Curvelo site only). The same trend was observed for FA, except in the Curvelo site. A trend for degradation and smaller contribution of O-alkyl C (carbohydrates) in HA was observed in soils under eucalyptus in Atlantic Forest and Cerrado. For FA such decreases were seen in Cerrado and Grassland biomes after eucalypt planting. In the area cultivated with pasture in the Atlantic Forest biome and in the Grassland soil, the largest contributions of lignin-derived compounds were detected in HA. The HA from the Cerrado at the Curvelo site, where the woody vegetation is virtually devoid of grassy species, showed the lowest intensity of lignin signal then those from the Cerrado sensu stricto in Itacambira, where grass species are more abundant. At our study sites, charred material are most likely derived from burning of the native vegetation, as naturally occurs in the Cerrado region, or anthropogenic fires in the Grassland biome. Burning of harvest residues in eucalypt fields was also a common practice in the early rotations. The replacement of native vegetation by eucalypt plantations increases the relative contribution of nonpolar alkyl groups in HA from soils previously under Atlantic Forest, Grassland, and the Cerrado (Curvelo site only) biomes. There is evidence of substantial contribution of lignin-derived C to HA and FA, especially in sites planted with Brachiaria sp pastures. Eucalypt introduction decreases the relative contribution of carbohydrates in HA and FA. 13C DP/MAS NMR functional groups in

  20. Root adaptations to soils with low fertility and aluminium toxicity

    PubMed Central

    Rao, Idupulapati M.; Miles, John W.; Beebe, Stephen E.; Horst, Walter J.

    2016-01-01

    Background Plants depend on their root systems to acquire the water and nutrients necessary for their survival in nature, and for their yield and nutritional quality in agriculture. Root systems are complex and a variety of root phenes have been identified as contributors to adaptation to soils with low fertility and aluminium (Al) toxicity. Phenotypic characterization of root adaptations to infertile soils is enabling plant breeders to develop improved cultivars that not only yield more, but also contribute to yield stability and nutritional security in the face of climate variability. Scope In this review the adaptive responses of root systems to soils with low fertility and Al toxicity are described. After a brief introduction, the purpose and focus of the review are outlined. This is followed by a description of the adaptive responses of roots to low supply of mineral nutrients [with an emphasis on low availability of nitrogen (N) and phosphorus (P) and on toxic levels of Al]. We describe progress in developing germplasm adapted to soils with low fertility or Al toxicity using selected examples from ongoing breeding programmes on food (maize, common bean) and forage/feed (Brachiaria spp.) crops. A number of root architectural, morphological, anatomical and metabolic phenes contribute to the superior performance and yield on soils with low fertility and Al toxicity. Major advances have been made in identifying root phenes in improving adaptation to low N (maize), low P (common bean) or high Al [maize, common bean, species and hybrids of brachiariagrass, bulbous canarygrass (Phalaris aquatica) and lucerne (Medicago sativa)]. Conclusions Advanced root phenotyping tools will allow dissection of root responses into specific root phenes that will aid both conventional and molecular breeders to develop superior cultivars. These new cultivars will play a key role in sustainable intensification of crop–livestock systems, particularly in smallholder systems of the

  1. Pore size distribution of a deeply excavated Oxisol after 19 years reclamation

    NASA Astrophysics Data System (ADS)

    dos Santos Batista Bonini, Carolina; de Cássia Marchini, Débora; Alves, Marlene Cristina; García de Arruda, Otton; Paz-Ferreiro, Jorge

    2013-04-01

    Digging of the local soil and using it as a raw material for construction purposes has been identified as a non-negligible source of land degradation. Techniques aimed at soil profile reconstruction and ecological restoration of soils truncated by mechanical excavation using heavy machinery have been investigated Both, total soil porosity and pore size distribution are important properties for soil management as well as for assessing the recovery of soil function after land degradation. In this way, macropores are responsible for aeration, whereas water storage depends on soil meso- and micropores in the soil and the optimal pore-size distribution is also an indicator of soil quality. We investigated the changes in the pore size distribution of a soil that was beheaded to extract raw materials after a 19 year period of reclamation, which involved the use of green manures, gypsum and pasture for the purpose of profile recovery. The studied area is located in Mato Grosso do Sul State, Brzil. A field trial was performed following a completely randomized experimental design with seven treatments and four replications. Starting 1992, the initial treatments were: 1) control (tilled bare soil), 2)Stizolobium aterrium, 3)Cajanus cajan, 4)lime+S. aterrimum, 5) lime+C. cajan, 6) lime + gypsum + S. aterrimum, 7) lime + gypsum+C. cajan. In 1994, all treatments with C. cajan were replaced by Canavalia ensiformis and in 1999, Brachiaria decumbens was implanted in all the experimental plots. Data from vegetated treatments were compared with bare soil (control) and native vegetation (Savannah). Soil samples were collected in 2011 at the 0.00-0.10, 0.10-0.20, and 0.20-0.40 m depths. Treatment differences were assessed by analysis of variance, following the Scott-Knott test (5%) of probability to compare averages. Macroporosity of the 0.00-0.10 m top layer was above the 0.10 m3m-3 threshold considered as critical for plant growth. On the 0.10-0.20 m layer only treatments with C

  2. Caesium-137 soil-to-plant transfer for representative agricultural crops of monocotyledonous and dicotyledonous plants in post-Chernobyl steppe landscape

    NASA Astrophysics Data System (ADS)

    Paramonova, Tatiana; Komissarova, Olga; Turykin, Leonid; Kuzmenkova, Natalia; Belyaev, Vladimir

    2016-04-01

    The accident at the Chernobyl nuclear power plant in 1986 had a large-scale action on more than 2.3 million hectares agricultural lands in Russia. The area of radioactively contaminated chernozems of semi-arid steppe zone with initial levels of Cs-137 185-555 kBq/m2 in Tula region received the name "Plavsky radioactive hotspot". Nowadays, after the first half-life period of Cs-137 arable chernozems of the region are still polluted with 3-6-fold excess above the radioactive safety standard (126-228 kBq/m2). Therefore, qualitative and quantitative characteristics of Cs-137 soil-to-plant transfer are currently a central problem for land use on the territory. The purpose of the present study was revealing the biological features of Cs-137 root uptake from contaminated arable chernozems by different agricultural crops. The components of a grass mixture growing at the central part of Plavsky radioactive hotspot with typical dicotyledonous and monocotyledonous plants - galega (Galega orientalis, Fabaceae family) and bromegrass (Bromus inermis, Gramineae family) respectively - were selected for the investigation, that was conducted during the period of harvesting in 2015. An important point was that the other factors influenced on Cs-137 soil-to-plant transfer - the level of soil pollution, soil properties, climatic conditions, vegetative phase, etc. - were equal. So, biological features of Cs-137 root uptake could be estimated the most credible manner. As a whole, general discrimination of Cs-137 root uptake was clearly shown for both agricultural crops. Whereas Cs-137 activity in rhizosphere 30-cm layer of arable chernozem was 371±74 Bq/kg (140±32 kBq/m2), Cs-137 activities in plant biomass were one-two orders of magnitude less, and transfer factor (TF) values (the ratio of the Cs-137 activities in vegetation and in soil) not exceeded 0.11. At the same time bioavailability of Cs-137 for bromegrass was significantly higher than for galega: TFs in total biomass of the

  3. Soil-Water Repellency and Critical Humidity as Cleanup Criteria for Remediation of a Hydrocarbon Contaminated Mud

    NASA Astrophysics Data System (ADS)

    Guzmán, Francisco Javier; Adams, Randy H.

    2010-05-01

    The majority of soil remediation programs focus mainly on reducing the hydrocarbon concentration, based on the assumption that the primary impact is toxicity and/or leachates and that these are directly proportional to concentration. None-the-less, interference with natural soil-water interactions are frequently more damaging, especially for sites contaminated with very viscous, weathered hydrocarbons. Therefore, the kind of hydrocarbons present in the soil and their interactions with soil surfaces may be more important than the overall hydrocarbon concentration in terms of soil restoration. One recently patented technology, the Chemical-Biological Stabilization process, focuses specifically on restoring soil fertility as the main objective for remediation of sites with agricultural use. This method was recently validated at an industrial scale by the treatment of 150 cubic meters of bentonitic drilling muds (70,5% fines) from an old sulphur mine, which were contaminated with very weathered oil (4° API), consisting of 31% asphaltenes. This material was treated by adding 4% (w/w, dry) of calcium hydroxide, followed by 4% (w/w, dry) of sugar cane cachasse (a fine fibered agricultural waste), thoroughly mixing between additions using an excavator. After the soil had dried sufficiently and the pH was <8, a fine-rooted, C-4 tropical grass (Brachiaria humidicola) was planted by seed. Over a two year period this material was monitored for several factors including field moisture (%H), field capacity (FC), and soil water repellency. MED was measured on air dried soil and WDPT values were calculated from the extrapolation of penetration time vs. ethanol molarity functions (Rx=0,99). Additionally, water penetration times were measured at different humidities to determine critical moisture levels for absorption in <5s and <60s. Initially, the FC increased from 24,9%H to 33,8%H (in 4½ months), probably due to the addition of the organic amendment. Over the next 6½ months

  4. Effects of Sapindus saponaria fruits on ruminal fermentation and duodenal nitrogen flow of sheep fed a tropical grass diet with and without legume.

    PubMed

    Abreu, A; Carulla, J E; Lascano, C E; Díaz, T E; Kreuzer, M; Hess, H D

    2004-05-01

    Six adult African-type hair sheep (BW = 40.3 +/- 6.3 kg) fitted with ruminal and duodenal cannulas were subjected to four treatments. Sheep were offered basal diets at a rate of 80 g of DM/kg of metabolic BW (equivalent to ad libitum access) consisting either of a low-quality grass hay (Brachiaria dictyoneura, 3.7% CP, DM basis) alone or in combination with a forage legume (Cratylia argentea, 18.6% CP, DM basis) in a 3:1 ratio (DM basis). In addition, 0 or 8 g of DM of Sapindus saponaria fruits (12.0% crude saponins, DM basis) per kilogram of metabolic BW was administered intraruminally. Supplementation of C. argentea increased intakes of OM (+21%; P < 0.01) and CP (+130%; P < 0.001), as well as ruminal fluid ammonia N concentrations (from 2.40 to 8.43 mg/dL; P < 0.001). Apparent OM and N digestibilities were not affected by legume addition, but ADF digestibility decreased by 10% (P < 0.01). Total ruminal VFA concentration was unchanged, but acetate:propionate was lower (P < 0.01) and isobutyrate proportion was greater (P < 0.001) with the legume addition. Legume supplementation increased duodenal flows of total N (+56%; P < 0.001), nonammonia N (+52%; P < 0.001), ruminal escape N (+80%; P < 0.001), and microbial N (+28%; P < 0.05). Microbial efficiency was not affected by legume addition. Supplementation of S. saponaria increased (P < 0.05) dietary OM intake by 14%, but had no effect on CP intake and ruminal fluid ammonia concentration or on OM and N digestion. Digestibility of ADF was decreased (P < 0.01) by 10% with S. saponaria as was acetate:propionate (P < 0.001) and the isobutyrate proportion (P < 0.001). Ruminal protozoa counts increased (P < 0.01) by 67% with S. saponaria. Duodenal N flows were not significantly affected by S. saponaria supplementation, except for microbial N flow (+34%; P < 0.01). Microbial efficiency was greater (P < 0.05) by 63% with the addition of S. saponaria. Few interactions between legume and S. saponaria supplementation were

  5. Phosphorus, carbon- and nitrogen interactions in productive and degraded tropical pastures

    NASA Astrophysics Data System (ADS)

    Oberson, A.; Hegglin, D. D.; Nesper, M.; Rao, I.; Fonte, S.; Ramirez, B.; Velasquez, J.; Tamburini, F.; Bünemann, E. K.; Frossard, E.

    2011-12-01

    Pastures are the main land use in deforested areas of tropical South America. The highly weathered soils of these regions usually have low total and available phosphorus (P) contents. Low P availability can strongly limit plant and animal productivity and other soil ecosystem functions. Most introduced pastures of Brachiaria spp. are grass-alone (GA) while some are grass-legume (GL) pastures. The majority of the introduced pastures, particularly the grass-alone are at some state of degradation (GD). Pasture degradation induces severe loss of plant biomass production, with drastic ecological and economic implications. Although the importance of P deficiency in pasture degradation has been recognized, the knowledge generated on stoichiometry of carbon (C), nitrogen (N) and P along pathways of the nutrient cycles of pastures, with different botanical composition and productivity, has been very limited. We will present results of a case study realized during 2010 to 2011 in the forest margins agro-ecosystem of the department of Caquetá, Colombia. Our objectives were to determine: i) whether P availability is lower in degraded compared to productive pastures, and ii) whether the introduction of legumes in the pasture increases P availability through enhanced biological P cycling through plant growth, plant litter decomposition and the soil microbial biomass; and iii) whether pasture types (GA vs GL) and the state of pasture degradation affect the C:N:P ratios in nutrient pools of the soil-plant system. An on-farm study was conducted on nine farms in the department of Caquetá, Colombia. On every farm three different pasture types were studied: degraded grass alone pastures (GD), productive grass-alone pastures (GA) and productive grass-legume pastures (GL). Basic soil characteristics and indicators on soil P status, microbial P cycling, plant biomass production, plant litter deposition and nutrient concentrations in plant tissue were determined. Analysis of P, C and N

  6. Changes in CO2, N2O and NO Emissions in Response to Conventional Tillage and No-tillage Management Practices in the State of Rondonia, Brazil

    NASA Astrophysics Data System (ADS)

    Passianoto, C. C.; Ahrens, T. D.; Feigl, B. J.; Steudler, P. A.; Do Carmo, J. B.; Melillo, J. M.

    2002-12-01

    Land management in the Brazilian State of Rondonia is undergoing a new phase at the start of 21st century. In the 1970s and afterwards, vast tracts of tropical forest were cleared and planted to pasture for cattle grazing. With decades of use, the productivity of these pastures has declined. Now, in an effort to restore productivity, new land management regimes are being implemented that involve either tillage or no-tillage options combined with various combinations of fertilizer application, herbicide use and the planting of a cash crop prior to the planting of forage grasses. We are studying a subset of these restoration practices in a large-scale (>3 ha), replicated field experiment in an area of degraded pasture at Fazenda Nova Vida, a 22,000 ha cattle ranch in central Rondonia. Here we report on the emissions of carbon dioxide (CO2), nitrous oxide (N2O) and nitric oxide (NO) from the initial phases (first six months) of three of the treatments. The treatments are - 1) control; 2) conventional tillage followed by planting of forage grass (Brachiaria brizantha) and fertilizer additions; 3) no-tillage/herbicide treatment followed by two plantings, the first being a cash crop of rice followed by forage grass. In treatment 3, the rice was fertilized. Relative to the control, tillage increased CO2 emission by 37% over the first two months, while the no-tillage/herbicide regime decreased CO2 emissions by 7% over the same period. The cumulative N2O emissions over the first two months from the tillage regime (0.94 kg N ha-1) were much higher than the N2O releases from either the no-tillage/herbicide regime (0.64 kg N ha-1) or the control treatment (0.04 kg N ha-1). The highest levels of N2O fluxes from both management regimes were observed following nitrogen fertilizations. The cumulative NO releases over the first two months were largest in the tillage treatment (0.98 kg N ha-1), intermediate in the no-tillage treatment (0.72 kg N ha-1), and smallest in the control

  7. The period from the Last Interglacial to the Last Glacial Maximum (MIS 5 - 2) in different archives of southern Italy

    NASA Astrophysics Data System (ADS)

    Sauer, Daniela; Wagner, Stephen; Al-Sharif, Riyad; Brückner, Helmut; Scarciglia, Fabio; Mastronuzzi, Giuseppe; Stahr, Karl

    2010-05-01

    Sediment cores from S Italy provide excellent archives of Late Pleistocene climate and vegetation changes, particularly from the Lago Grande di Monticchio (Allen et al., 2000; Brauer et al., 2007), the crater lakes of the central West coast of Italy, Valle di Castiglione, Lagaccione, Lago di Vico, Stracciacappa (Follieri et al., 1998) and the marine core GNS84-C106 in the Gulf of Salerno (Di Donato et al., 2008). These records show that woody Mediterranean vegetation covered the region during most of the Last Interglacial (from 129-127 ka BP until 115-116 ka BP). In the last phase of the interglacial (from 115-116 ka BP until about 110 ka BP), the forest composition changed, showing an increase in Abies and Alnus and a decrease in Mediterranean taxa. The interglacial was terminated by the Melisey I Stadial, during which grasses and Betula predominated. Forests spread again during St. Germain I, but they consisted mainly of Fagus, Abies and various deciduous trees. A steppe phase (Melisey II) followed, in which Chenopodiaceae prevailed, before St. Germain II set in, with forests dominated by Abies, Ulmus and Carpinus. From the end of St. Germain II until the Lateglacial, steppe, composed of Artemisia, Gramineae and Chenopodiaceae, predominated, with week expansions of trees (mainly Pinus and Juniperus) during several periods. What information can be obtained from terrestrial geo-archives for the same region and time? Sea level highstands, corresponding to interglacial and interstadial periods, created marine terraces along the coasts of S Italy. We are currently carrying out a geomorphological, sedimentological and pedological study on a flight of 11 uplifted marine terraces in the central Gulf of Taranto, the lowermost of them falling into the time span of interest. The terraces generally comprise a gravel body, deposited in a littoral environment, covered by a layer of fine sediments of varying thickness. The latter were deposited when the terrace was still close

  8. Phytoreovirus-like sequences isolated from salivary glands of the glassy-winged sharpshooter Homolodisca vitripennis (Hemiptera: Cicadellidae)

    SciTech Connect

    Katsar, C.S.; Hunter, W.B. . E-mail: Whunter@ushrl.ars.usda.gov; Sinisterra, X.H.

    2007-03-15

    GWSS occurs, such as in southern California, will provide a better understanding of the potential role of the GWSS as a disease vector in the spread of phytoreoviruses and other plant pathogens. The sequences have been deposited in NCBI database under the accession numbers (EF058280) for GWSS-V1, WHSg013C11 and (EF058281) for GWSS-V2, WHSg024H02. (author) [Spanish] Dos fragmentos de 610 y 839 pares de bases fueron aislados apartir de una genoteca de expresion derivada de las glandulas salivales del cucarron de las alas cristalinas (GWSS), Homalodisca vitripennis, Germar 1821 (syn. H. coagulata) el cual es vector de la enfermedad de Pierce de las uvas. Los resultados de alineamiento utilizando BLASTX, BLASTP y el analisis filogenetico utilizando PAUP indicaron que los fragmentos de DNA estaban relacionado de manera mas cercana a viruses en la familia Reoviridae, genero Phytoreovirus, y especificamente a los virus del enanismo del arroz (RDV) y al virus del tumor de las grietas (WTV). El cucarron de las alas cristalinas es un saltahoja que se alimenta no solo del xilema sino tambien del floema y del mesofilo. Saltahojas del genero Agallian, son los principales vectores de WTV, el cual infecta el floema de plantas dicotiledoneas tumoraciones en las hojas y en las raices. WTV es transmitido por saltahojas y es el unico reovirus que es capaz de infectar tanto tejidos del xilema como del floema. El comportamiento alimentario del GWSS y su amplio rango de hospederos que incluye pastos y plantas herbaceas y lenosas podria proveer la interaccion entre estos dos organismos facilitando la adquisicion y tranmision de fitoreovirus por el GWSS. Un adecuado monitoreo de el incremento en la expansion de reoviruses en cultivos de gramineas asociados al los vinedos en donde GWSS ocurre en regiones tales como el sur de California, y en general el sur de los Estados Unidos, podria proveer un mejor entendimiento del papel del GWSS como vector de fitoreovirus y otros patogenos de plantas