Optimization of parameters for Agrobacterium mediated transformation of black gram (Vigna mungo L. Hepper) using cotyledon explants

Agrobacterium tumefaciens strain LBA4404 harbouring binary vector pCAMBIA 2301, which contains a neomycin phosphotransferase gene (nptII) and a β-glucuronidase (GUS) gene (uid A) was used for transformation of Vigna mungo cotyledon derived calli. Wounding of explants before infection, osmotic effects of infection and cocultivation media had an effect on the competence of the tissue as well as transforming ability of Agrobacterium cells. Transient GUS expression studies revealed that a cell density of 108 cells/ml, 100 μM acetosyringone and 330 μM cysteine were effective in increasing the transformation frequency and obtaining stable transformants with a 3.8% transformation efficiency. IBA pulse treatment was effective in root induction of kanamycin selected putative transformants. Molecular analysis using polymerase chain reaction (PCR) of nptII gene confirmed the transgenic nature of T0 transformants.Key words: Black gram, genetic transformation, Agrobacterium tumefaciens, cotyledon

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Not AvailableAn efficient protocol for shoot bud induction and proliferation employing half cotyledonary node with intact cotyledon explants derived from two-day-old seedlings of mung bean pre-conditioned on 6- benzylaminopurine (BAP) has been achieved. Explants were cultured for four weeks each on MS B5 + 12.5 μM BAP and MS B5 + 5 μM BAP +0.05 μM α- naphthaleneacetic acid (NAA ), respectively, as shoot bud induction and shoot elongation and proliferation media, gave the best regeneration response. The removal of the pre-existing buds from explants at 12 days in shoot bud induction medium led to enhanced regeneration response. Light microscopic observations on 14-day-old explants confirmed direct organogenesis route of regeneration. Elongated shoots (>2 cm) excised from the regenerating cultures were successfully rooted on half MS B5 medium containing 2.46 μM indolebutyric acid (IBA). About 90% of the rooted plantlets, efficiently hardened in pots having soil and farm yard manure, flowered and produced pods with viable seeds upon reaching maturity.Not Availabl

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Not AvailableElevated carbon dioxide is known to impact crop growth and productivity. Groundnut is a very important edible oilseed crop raised mostly under rainfed situations worldwide. In the present study, two cultivars of groundnut (Arachis hypogaea L.) viz., JL 24 and ICGV 91114 were raised in open top chambers at two elevated CO2 levels (550 and 700ppm) during Kharif 2010 to investigate the effect of raised levels of CO2 on various growth parameters and seed quality. The seed oil and protein contents were higher in JL 24 compared to ICGV 91114 in all the treatments and showed a declining trend with elevated carbon dioxide concentrations. The oil and protein contents in ICGV 91114 showed a decline at 550 ppm of CO2 and a slight increase at 700 ppm of CO2 . The saturated fatty acids (palmitic and stearic) showed a decreasing trend while oleic acid (omega-9) registered an increasing trend in JL 24 at elevated CO2 levels. The trend was similar in ICGV 91114 except at 550 ppm of CO2 where oleic acid registered a decline before an increase at 700 ppm. Linoleic acid (omega- 6) content decreased at 550 ppm and then increased slightly at 700 ppm of CO2 in JL 24, whereas it showed a reverse trend in ICGV 91114. In general, the saturated fatty acid levels decreased in both the genotypes while a corresponding increase was observed in unsaturated fatty acids under elevated CO2 concentrations which could prove to be beneficial from the human nutritional point of view under future changed climatic scenario.Not Availabl

Optimization of Agrobacterium mediated genetic transformation of cotyledonary node explants of Vigna radiata

Not AvailableA reproducible and highly efficient protocol for genetic transformation mediated by Agrobacterium has been established for greengram (Vigna radiata L. Wilczek). Double cotyledonary node (DCN) explants were inoculated with Agrobacterium tumefaciens strain LBA 4404 harboring a binary vector pCAMBIA 2301 containing neomycin phosphotransferase (npt II) gene as selectable marker, β-glucuronidase (GUS) as a reporter (uidA) gene and annexin 1 bj gene. Important parameters like optical density of Agrobacterium culture, culture quantity, infection medium, infection and co-cultivation time and acetosyringone concentration were standardized to optimize the transformation frequency. Kanamycin at a concentration of 100 mg/l was used to select transformed cells. Transient and stable GUS expressions were studied in transformed explants and regenerated putative plants, respectively. Transformed shoot were produced on regeneration medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime and rooted on ½ MS medium. Transient and constitutive GUS expression was observed in DCN explants and different tissues of T0 and T1 plants. Rooted T0 and T1 shoots confirming Polymerase Chain Reaction (PCR) positive for npt II and annexin 1bj genes were taken to maturity to collect the seeds. Integration of annexin gene into the greengram genome was confirmed by Southern blotting.Not Availabl

Mapping of QTLs for morphophysiological and yield traits under water-deficit stress and well-watered conditions in maize

Maize productivity is significantly impacted by drought; therefore, improvement of drought tolerance is a critical goal in maize breeding. To achieve this, a better understanding of the genetic basis of drought tolerance is necessary. Our study aimed to identify genomic regions associated with drought tolerance-related traits by phenotyping a mapping population of recombinant inbred lines (RILs) for two seasons under well-watered (WW) and water-deficit (WD) conditions. We also used single nucleotide polymorphism (SNP) genotyping through genotyping-by-sequencing to map these regions and attempted to identify candidate genes responsible for the observed phenotypic variation. Phenotyping of the RILs population revealed significant variability in most of the traits, with normal frequency distributions, indicating their polygenic nature. We generated a linkage map using 1,241 polymorphic SNPs distributed over 10 chromosomes (chrs), covering a total genetic distance of 5,471.55 cM. We identified 27 quantitative trait loci (QTLs) associated with various morphophysiological and yield-related traits, with 13 QTLs identified under WW conditions and 12 under WD conditions. We found one common major QTL (qCW2–1) for cob weight and a minor QTL (qCH1–1) for cob height that were consistently identified under both water regimes. We also detected one major and one minor QTL for the Normalized Difference Vegetation Index (NDVI) trait under WD conditions on chr 2, bin 2.10. Furthermore, we identified one major QTL (qCH1–2) and one minor QTL (qCH1–1) on chr 1 that were located at different genomic positions to those identified in earlier studies. We found co-localized QTLs for stomatal conductance and grain yield on chr 6 (qgs6–2 and qGY6–1), while co-localized QTLs for stomatal conductance and transpiration rate were identified on chr 7 (qgs7–1 and qTR7–1). We also attempted to identify the candidate genes responsible for the observed phenotypic variation; our analysis revealed that the major candidate genes associated with QTLs detected under water deficit conditions were related to growth and development, senescence, abscisic acid (ABA) signaling, signal transduction, and transporter activity in stress tolerance. The QTL regions identified in this study may be useful in designing markers that can be utilized in marker-assisted selection breeding. In addition, the putative candidate genes can be isolated and functionally characterized so that their role in imparting drought tolerance can be more fully understood

Minutes, 2009 December 10

<p>* Indicate the statistical significance compared over baseline (BL) period at p<0.01.</p><p>Inter Scenario variation in generation time of <i>S. litura</i> in future climate change scenarios across peanut growing locations.</p

Model and Scenario Variations in Predicted Number of Generations of <i>Spodoptera litura</i> Fab. on Peanut during Future Climate Change Scenario

<div><p>The present study features the estimation of number of generations of tobacco caterpillar, <i>Spodoptera litura</i>. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM) of future data on daily maximum (T.max), minimum (T.min) air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1). This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF) -2020, Distant future (DF)-2050 and Very Distant future (VDF)—2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1–2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18–22% over baseline. Analysis of variance (ANOVA) was used to partition the variation in the predicted number of generations and generation time of <i>S. litura</i> on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%), model (1.74%) and scenario (0.74%). The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of <i>S. litura</i> may increase due to projected increase in temperatures in future climate change periods.</p></div

Inter Model and Scenario variation in number of generations of <i>S. litura</i> in future climate change scenarios.

<p>Inter Model and Scenario variation in number of generations of <i>S. litura</i> in future climate change scenarios.</p

Details and Abbreviations of Models.

<p>Details and Abbreviations of Models.</p

Inter model and Scenario variation in generation time of <i>S. litura</i> in future climate change scenarios.

<p>Inter model and Scenario variation in generation time of <i>S. litura</i> in future climate change scenarios.</p