112 research outputs found

    Agronomic Traits in Tall Fescue Populations under Irrigated and Rain-Fed Conditions

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    Grasslands and native rangelands are the predominant land-use all over the world. Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] is a cool-season perennial grass widely grown throughout the temperate regions of the world and an important component of the grasslands. Drought can have serious consequences on performance of agriculture, soil and plant health, and economics. Developing drought tolerant plants that can maintain productivity during drought, will have great environmental and economic benefits to farmers. A tall fescue population was developed by crossing a drought tolerant genotype to a susceptible genotype. The population was evaluated for different morphological and yield traits under irrigated and rain-fed conditions at the University of Wyoming, USA. Large variations among the 252 tall fescue genotypes for several traits of interest have been observed. Plants under irrigated conditions were about 1.5 times more vigorous and 1.9 times taller than those grown in rain-fed conditions. Rain-fed conditions greatly reduced the tillering ability (\u3c 2.6 fold) of tall fescue plants. Plants under irrigated conditions were 2.9 times more productive than those grown in rain-fed condition. The largest difference in a year for water content (WC) between the plants grown in the two conditions was 8.06%. Genotypes with better tolerance to drought have been identified in the population which could be useful to develop drought tolerant tall fescue cultivars

    Dig Up Tall Fescue Plastid Genomes For The Identification of Morphotype-Specific DNA Variants

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    Background Tall fescue (Festuca arundinacea Schreb.) is an important cool-season perennial grass species. Hexaploid tall fescue has three distinct morphotypes used either as forage or turf purposes. Its chloroplast genome is conserved due to it being maternally inherited to the next generation progenies. To identify morphotype-specific DNA markers and the genetic variations, plastid genomes of all three tall fescue morphotypes, i.e., Continental cv. Texoma MaxQ II, Rhizomatous cv. Torpedo, and Mediterranean cv. Resolute, have been sequenced using Illumina MiSeq sequencing platform. Results The plastid genomes of Continental-, Rhizomatous-, and Mediterranean tall fescue were assembled into circular master molecules of 135,283 bp, 135,336 bp, and 135,324 bp, respectively. The tall fescue plastid genome of all morphotypes contained 77 protein-coding, 20 tRNAs, four rRNAs, two pseudo protein-coding, and three hypothetical protein-coding genes. We identified 630 SNPs and 124 InDels between Continental and Mediterranean, 62 SNPs and 20 InDels between Continental and Rhizomatous, and 635 SNPs and 123 InDels between Rhizomatous and Mediterranean tall fescue. Only four InDels in four genes (ccsA, rps18, accD, and ndhH-p) were identified, which discriminated Continental and Rhizomatous plastid genomes from the Mediterranean plastid genome. Here, we identified and reported eight InDel markers (NRITCHL18, NRITCHL35, NRITCHL43, NRITCHL65, NRITCHL72, NRITCHL101, NRITCHL104, and NRITCHL110) from the intergenic regions that can successfully discriminate tall fescue morphotypes. Divergence time estimation revealed that Mediterranean tall fescue evolved approximately 7.09 Mya, whereas the divergence between Continental- and Rhizomatous tall fescue occurred about 0.6 Mya. Conclusions To our knowledge, this is the first report of the assembled plastid genomes of Rhizomatous and Mediterranean tall fescue. Our results will help to identify tall fescue morphotypes at the time of pre-breeding and will contribute to the development of lawn and forage types of commercial varieties

    Characterization of non polar-polar solvent extracts from some tea plantation shade tree leaves with special reference to antioxidant and antibacterial activities

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    Beneficial properties of shade trees of tea plantations other than their medicinal properties have been extensively studied. This research was initiated to explore the properties of some shade trees with special emphasis on their antioxidant and antibacterial properties. Leaves from shade tree like Dalbergia sissoo (DS), Cassia siamea (CS), Derris robusta (DR), Leucaena leucocephala (LL), Acacia lenticularis (AL) and Melia azedarach (MA) were used for the study. Characterization of shade tree leaves by determination of moisture, crude fibre and ash content and tests of non polar – polar solvent extracts for steroid, tannins, cardiac glycosides and coumarin, free radical scavenging, ferric reducing power, NO scavenging activities, quantification of Flavonoids and antibacterial activity were conducted. The average moisture, crude fibre and ash percentage of shade tree plants were found to be 62.95, 11.28 and 1.86 respectively. Methanol, ethanol, acetone and ethyl acetate respectively proved to be the most potent solvent for various phytochemical extractions as it gave positive results for tests like tannin, steroid, cardiac glycosides and coumarin. AL (91.46%), DR (92.69%), LL (94.32%) and MA (93.34%) leaf extracts showed a high level of DPPH scavenging activity in their water extracts. In DS (88.11%) and CS (83.23%) maximum DPPH scavenging activity was observed in Diethyl ether and Methanol extracts respectively.  Acetone extracts were more active than the water extracts in exhibiting ferric reducing power and NO scavenging activity. Summation of the quantity revealed that DS showed maximum presence of flavonoids and acetone as most potential for isolation of flavonoids. The decreasing order of summative antibacterial activity was recorded in DS, followed by CS, DR, AL, MA and LL. Chloroform showed the highest summative inhibition zone followed by ethanol, ethyl acetate, diethyl ether, acetone, water,  hexane, benzene and methanol. The antioxidant and antibacterial potential of shade trees were established

    Normal form for singular Bautin bifurcation in a slow-fast system with Holling type III functional response

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    Over the last few decades, complex oscillations of slow-fast systems have been a key area of research. In the theory of slow-fast systems, the location of singular Hopf bifurcation and maximal canard is determined by computing the first Lyapunov coefficient. In particular, the analysis of canards is based on the genericity condition that the first Lyapunov coefficient must be non-zero. This manuscript aims to further extend the results to the case where the first Lyapunov coefficient vanishes. For that, the analytic expression of the second Lyapunov coefficient and the investigation of the normal form for codimension-2 singular Bautin bifurcation in a predator-prey system is done by explicitly identifying the locally invertible parameter-dependent transformations. A planar slow-fast predator-prey model with Holling type III functional response is considered here, where the prey population growth is affected by the weak Allee effect, and the prey reproduces much faster than the predator. Using geometric singular perturbation theory, normal form theory of slow-fast systems, and blow-up technique, we provide a detailed mathematical investigation of the system to show a variety of rich and complex nonlinear dynamics including but not limited to the existence of canards, relaxation oscillations, canard phenomena, singular Hopf bifurcation, and singular Bautin bifurcation. Additionally, numerical simulations are conducted to support the theoretical findings

    Mother-to-child HIV transmission and its correlates in India: systematic review and meta-analysis

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    BACKGROUND: In India, preventing mother-to-child transmission (PMTCT) of Human Immunodeficiency Virus (HIV) remains one of the foremost challenge in community health. Countrywide MTCT of HIV is estimated to be > 10,000 annually. Aims of present study are to find out the prevalence of HIV and correlates of HIV transmission among children given birth by HIV infected mother through systematic review along with meta-analysis. METHODS: All avaiable articles are retrieved using MEDLINE, Cochrane Library, Science Direct, EMBASE, Google Scholar and PUBMED following guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) are applied to critically reviewing the selected articles. STATA 13.0 is used to preparation of forest plot for Meta-analysis. For assessment of heterogeneity and publication biases I2 statistics along with Begg and Mazumdar's test and Egger's tests are used. Odds ratio (OR) along with forest plots have been showing with 95% confidence interval (CI). RESULTS: All together 10 studies including 1537 pairs of mothers and new births are assessed in present meta-analysis. Present analysis revealed the prevalence of HIV due to MTCT in India as 8.76% (95% CI; 5.76, 12.31). Analysis of subgroups exhibit a higher pooled prevalence in eastern region of India, 10.83% (95% CI: 5.9, 17.81) and lower in in Western region in India, 6.37% (95% CI: 4.65, 8.49). Status of MTCT before and after initiation of universal ART are 10.23% (95% CI 6.61, 14.55) and 7.93% (95% CI 4.18, 12.76) respectively. Associated factors with MTCT of HIV include absence of maternal prevention of MTCT intervention, OR = 10.82 (95% CI: 5.28, 22.17), lacking in administration of infant ARV (antiretroviral), OR = 8.21 (95% CI: 4.82, 14.0) and absence of medical facility during childbirth OR = 3.73 (95% CI: 1.67, 8.33). CONCLUSIONS: In India, pooled HIV prevalence of MTCT as high as 8.78% (95% CI; 5.76, 12.31) among babies born to infected mothers warrants urgent need of focused intervention for providing ART (PMTCT intervention), ensuring proper infant ARV prophylaxis, and avoiding delivery without proper medical facility to pregnant women with HIV for reduction of occurrence in HIV transmission from mothers to children

    Molecular Characterization of Jatropha curcas Resources and Identification of Population-Specific Markers

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    Jatropha curcas L. is cited as one of the best candidates for future oil and biodiesel production. It is widespread in many tropical and subtropical countries but has not yet received much genetic improvement. The objective of this study was to collect Jatropha germplasm and characterize it with molecular markers. A total of 64 genotypes, collected from seven geographic locations on two continents, were analyzed with 32 simple sequence repeat and two candidate gene-specific primers (ISPJ-1 gene and Curcin-P2 gene promoter). In general, markers were found to be highly conserved, and many (40%) were monomorphic in the studied populations. Polymorphic primers, which amplified population-specific fragments, were identified. The polymorphic information content of the polymorphic markers ranged from 0.03 to 0.47. Genetic similarity analysis identified two distinct groups at 0.73 DICE similarity coefficient. Group I included germplasm collected from the islands of Cuba and Cape Verde, and group II consisted of Brazil, Mozambique, and Senegal populations. Island genotypes were found to be very distinct compared to their mainland counterparts. Sequencing of monomorphic fragments identified single nucleotide polymorphism (SNP) between these two groups. High-resolution melting analysis of the SNP in the Jcps9 locus further confirmed the two gene pools. Sequencing of polymorphic fragments of the Jc03 locus identified a deletion in a (GT)4 repeat motif in the genotypes in group II. Several population-specific microsatellites and SNP markers have been recognized. The distinct Jatropha genotypes and the population-specific molecular markers identified in this study will be valuable resources in breeding programs

    Tall Fescue Expressed Sequence Tag and Simple Sequence Repeats: Important Resources for Grass Species

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    Expressed sequence tag (EST) databases have been growing exponentially. The simple sequence repeat (SSR) has become one of the most useful molecular marker systems in plant breeding and is widely used in cultivar fingerprinting, genetic diversity assessment, molecular mapping and marker-assisted selection. ESTs are a potential source for SSRs. The EST-SSR markers are of high quality and have versatile applications in molecular breeding (Bughrara et al., 2003; Saha et al., 2004 a, b, c). Here, we present an overview of our efforts to develop SSRs from tall fescue ESTs and their application for the genetic improvement of forage and turf grass species

    Isolation of intact chloroplast for sequencing plastid genomes of five festuca species

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    Isolation of good quality chloroplast DNA (cpDNA) is a challenge in different plant species, although several methods for isolation are known. Attempts were undertaken to isolate cpDNA from Festuca grass species by using available standard protocols; however, they failed due to difficulties separating intact chloroplasts from the polysaccharides, oleoresin, and contaminated nuclear DNA that are present in the crude homogenate. In this study, we present a quick and inexpensive protocol for isolating intact chloroplasts from seven grass varieties/accessions of five Festuca species using a single layer of 30% Percoll solution. This protocol was successful in isolating high quality cpDNA with the least amount of contamination of other DNA. We performed Illumina MiSeq paired-end sequencing (2 × 300 bp) using 200 ng of cpDNA of each variety/accession. Chloroplast genome mapping showed that 0.28%–11.37% were chloroplast reads, which covered 94%–96% of the reference plastid genomes of the closely related grass species. This improved method delivered high quality cpDNA from seven grass varieties/accessions of five Festuca species and could be useful for other grass species with similar genome complexity

    Hepatitis B Infection, Eastern India

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    Transcriptome of Endophyte-Positive and Endophyte-Free Tall Fescue Under Field Stresses

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    This article is a study that represents the first transcriptome analysis of E+ and E− Texoma tall fescue under freezing and chilling temperatures in the natural field environment
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