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Sivakumar P.,ADAC and RI | Rajesh S.,National Research Center for Soybean | Gnanam R.,Tamil Nadu Agricultural University | Manickam A.,Tamil Nadu Agricultural University
Acta Biologica Hungarica | Year: 2011

We report a high frequency regeneration protocol in cowpea (Vigna unguiculata Walp. var. C 152) via somatic embryogenesis from 10-d-old primary leaf explants. A study was conducted to examine the effect of somaclonal variations in in vitro derived cowpea plants under field conditions. The regenerated plantlets were successfully transferred to field after hardening in vitro and grown for collecting R0, R1 and R2 seeds. The seeds of R1 and R2 generations were subsequently, grown under field conditions and their various biometrical traits were compared and evaluated with non-tissue cultured cowpea plants as check. There was no detectable somaclonal variation induced in R0- R2 in any of the biometrical traits. The results indicate that the inclusion of different plant growth promoters at specified concentrations and duration in our earlier tissue culture work did not induce any detectable mutation. The RAPD analysis also shows that there is no genetic variation among R2 cowpea plants. The somatic embryogenesis protocol we report could thus be safely applied for high frequency true-to-type regeneration and transformations protocols without any somaclonal variation. © 2011 Akadémiai Kiadó, Budapest.

Alderman P.D.,University of Florida | Alderman P.D.,International Maize and Wheat Improvement Center | Boote K.J.,University of Florida | Jones J.W.,University of Florida | Bhatia V.S.,National Research Center for Soybean
Field Crops Research | Year: 2015

Pigeonpea (Cajanus cajan (L.) Millsp.) is an important crop in Asia, Africa, Latin America and Caribbean. Despite pigeonpea's global importance there is a dearth of crop simulation models available for studying pigeonpea growth. The objectives of this study were to adapt the CSM-CROPGRO model for simulating pigeonpea growth and development through parameter modification and to illustrate the use of a sequential parameter estimation technique using a dataset from Gainesville, FL in 1984 and a dataset from India in 2003. The sequential approach to parameter estimation using a hybrid Metropolis-Hastings-Gibbs algorithm worked well at estimating physiologically plausible values for parameters with good correspondence to measured data. Reasonable results were obtained despite the use of approximations for measurement errors for the Gainesville dataset, which contained only treatment means. This study demonstrated that CROPGRO can be used to simulate the growth and development of pigeonpea. However, further testing of CROPGRO with more extensive pigeonpea datasets should be undertaken to confirm the accuracy of the parameter estimates developed from this study. Further theoretical and practical research into the parameter estimation approach is needed. © 2015 Elsevier B.V.

Jumrani K.,National Research Center for Soybean | Bhatia V.S.,National Research Center for Soybean
Field Crops Research | Year: 2014

High temperatures due to significant change in cropping systems and global warming are threatening chickpea production in its current area of cultivation. However, there are limited studies elucidating the impact of elevated temperature on development, growth and yield of chickpea. The present study was aimed at understanding the physiological response of chickpea cultivars when grown at elevated temperatures. Three cultivars (BG 256, JG 412 and JG 218) were grown at day/night temperatures of 26/16, 30/18, 34/20 and 38/22°C under green-house conditions. One set was also grown under ambient conditions where crop season average maximum and minimum temperatures were 25.5 and 12.1°C, respectively. Onset of flowering and maturity were hastened progressively as the temperatures increased. The rate of leaf area development and vegetative biomass was significantly higher at 26/16 and 30/18°C compared with ambient, 34/20 and 38/22°C. Increased vegetative growth was not reflected in seed yield which was highest (16gplant-1) in plants grown at ambient temperature and significantly declined at elevated temperatures. The reduction in yield was low (10%) at 26/16°C, moderate (23%) at 30/18°C and very severe at 34/18°C (64%) and 38/22°C (78%). The yield related traits most affected by high temperature were pod number and harvest index. Reduced pod number was mainly on account of reduction in reproductive efficiency (pod to flower ratio) indicating that under high temperatures reproductive development was impaired. Cultivar BG 256 performed relatively better than other two cultivars and significant interaction of cultivars with temperature was observed for most of the traits studied. It is concluded that for heat tolerance in chickpea, breeding efforts needs to be focused on improving the reproductive efficiency. © 2014 Elsevier B.V.

Singh R.K.,National Research Center for Soybean | Singh R.K.,Indian Agricultural Research Institute | Bhatia V.S.,National Research Center for Soybean | Bhat K.V.,National Research Center for Fingerprinting | And 4 more authors.
Genetics and Molecular Biology | Year: 2010

Forty-four soybean genotypes with different photoperiod response were selected after screening of 1000 soybean accessions under artificial condition and were profiled using 40 SSR and 5 AFLP primer pairs. The average polymorphism information content (PIC) for SSR and AFLP marker systems was 0.507 and 0.120, respectively. Clustering of genotypes was done using UPGMA method for SSR and AFLP and correlation was 0.337 and 0.504, respectively. Mantel's correlation coefficients between Jaccard's similarity coefficient and the cophenetic values were fairly high in both the marker systems (SSR = 0.924; AFLP = 0.958) indicating very good fit for the clustering pattern. UPGMA based cluster analysis classified soybean genotypes into four major groups with fairly moderate bootstrap support. These major clusters corresponded with the photoperiod response and place of origin. The results indicate that the photoperiod insensitive genotypes, 11/2/1939 (EC 325097) and MACS 330 would be better choice for broadening the genetic base of soybean for this trait. © 2010, Sociedade Brasileira de Genética.

Singh R.K.,National Research Center for Soybean | Singh R.K.,Indian Institute of Sugarcane Research | Tara Satyawathi C.,National Research Center for Soybean | Tara Satyawathi C.,Indian Agricultural Research Institute | And 2 more authors.
National Academy Science Letters | Year: 2010

The Indian soybean cultivare are derived from a limited number of ancestors, hence their genetic base are narrow. Knowledge of genetic diversity patterns in ancestors, cultivars and exotic germplasm provides better understanding for selection of diverse parents. The objective of this research was to assess the genetic diversity within and between three gene pools comprising of 11 Indian soybean ancestors (ISA), 21 Indian soybean cultivars and 23 exotic germplasm. A total of 548 DNA fragments were generated by 52 RAPD primers, of which 382 (69.7%) were polymorphic. The polymorphism information content (PIC) ranged from zero (monomorphic loci) to 0.5. Maximum genetic diversity (59.5±0.06) was observed between the Indian soybean cultivars and the exotic germplasm. Clustering and principal component analysis separated to these genotypes into three distinct groups corresponding to their genetic relationship and origin. Mantel test (r = 0.975) indicates very good fit for the clustering pattern with high bootstrap support (100%). The reported diversity patterns demonstrated a valuable guide for finding and incorporating new genes into elite Indian soybean.

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