Search

A field experiment was conducted during rabi season 2018-19 to study the response of 23 cowpea genotypes grown under residual moisture condition in rice-fallow situation of Goa state. Analysis of variance revealed significant differences among the genotypes for all the eleven characters, justifying the selection of genotypes for the study. The estimate of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were high (>20%) for seed yield, straw yield, pods per plant and 100 seed weight. Heritability and genetic advance as per cent mean estimates were high for most of the characters except for days to 50 per cent flowering, days to maturity and plant height. Characters plant height, pods per plant, straw yield and harvest index showed positive and significant association with seed yield. Path analysis based on seed yield, as a dependent variable, revealed that straw yield and harvest index had the highest positive direct effect on seed yield. Therefore, maximum importance should be given to these traits during the selection for achieving the higher seed yield under rice-fallow situation. Three promising genotypes identified from this study viz., PCP-1131, SKAU-C-407 and RC 101 would serve as dual-purpose cowpea under rice-fallow areas due to their high seed yield and straw yield. [ABSTRACT FROM AUTHOR]

Salt stress is a major abiotic stress affecting the productivity of rice crop worldwide. This study screened a set of 71 rice genotypes collected from coastal parts of Goa and Karnataka states in India for seedling stage salinity tolerance to identify genotypes alternative to standard salt-tolerant donors Pokkali, FL478, etc. Phenotyping for seedling stage tolerance was carried out under micro plots at an induced salinity of 12 dS/m. For haplotyping, 14 Saltol QTL linked simple sequence repeat (SSR) markers on chromosome 1 were utilized. On the basis of the response to salt stress, 10 genotypes were found tolerant, 16 moderately tolerant, 29 sensitive and 15 as highly sensitive. Among the SSR markers, marker RM10871 was the most polymorphic with a polymorphic information content of 0.90, exhibiting 14 different alleles followed by RM10793 (0.84) and RM3412 (0.80) with 8 and 7 alleles, respectively. These markers also exhibited high values for the effective number of alleles (Ne) and gene diversity (I). The haplotype analysis revealed that the allelic constitution of the Saltol region of 10 tolerant genotypes from our study varied in comparison to the reference tolerant check FL478. Further, the haplotype of three tolerant genotypes, namely, Goa Dhan 2, Panvel 1 and Goa wild rice (GWR) 005 appears to be completely different from the FL478 haplotype indicating tolerance in these genotypes is controlled by genomic region other than Saltol. These three genotypes with probable novel regions for seedling stage salt tolerance can be considered for enhancing salinity tolerance of rice cultivars. [ABSTRACT FROM AUTHOR]