Assessment of Genetic Variability and Pollen Viability in Rice (Oryza sativa L.) Germplasm for Low Temperature Tolerance at Reproductive Stage

A panel of rice genotypes consisting of the mini core, lowland and upland genotypes were evaluated for their ability to withstand cold stress to assess their genetic variability and pollen viability. The analysis of variance revealed highly significant differences among the genotypes for all the traits studied in ENV 1. Days to 50% flowering, plant height and spikelet fertility showed highest genotypic and phenotypic variance in all the three environments. Overall correlation analysis showed that spikelet fertility and biological yield were highly correlated with grain yield. Pollen viability test under cold stress condition relative to timely sown were studied and genotypes performing well were BAM 5889, BAM 5179, and BAM 4408. Among the mini core rice accessions studied, genotypes performing well under both timely and late sown environment were BAM 4115, UR 100, BAM 5179, BAM 3808, LR 11, BAM 4483 and UR 3.