Molecular characterization and genetic diversity of different rice (Oryza sativa L.) genotypes for salt tolerance

The present study involved evaluation of 12 genotypes of rice under control salt and field conditions. The characters studied were days to 50% flowering, plant height (cm), panicles bearing tillers/plant, spikelets/panicle, grains/panicle, panicle length, spikelet fertility (%), test weight (g), biological yield/plant (g), harvest index (%), and grain yield/plant (g).After 7 days of salinisation, all the genotypes viz., IR68144-2B-2-2-3-1-120, IR-68144-2B-2-2-3-1-127, IR-91167-99-1-1-1-3, IR-91167-133-1-1-2-3, NUD-3, NDR-359, IR-28, FL-478, NUD-2, CSR-13, Ayyar and NDRK-2008 were salinity tolerance. After 14 days of salinisation, FL-478 were tolerant, while IR68144-2B-2-2-3-1-120, IR-68144-2B-2-2-3-1-127, IR-91167-133-1-1-2-3, NUD-3, NUD-2 and CSR-13 were moderately tolerant genotypes and NDR-359 were susceptible genotype. After 21 days of salinisation, FL-478 were tolerant genotype, while IR-91167-99-1-1-1-3, NUD-3, NUD-2, CSR-13 and NDRK-2008 were moderately tolerant genotypes and genotypes IR68144-2B-2-2-3-1-120, IR-68144-2B-2-2-3-1-127, IR-91167-133-1-1-2-3, NDR-359, IR-28 and Ayyar were susceptible genotype. Under salinity condition at reproductive stages of rice genotypes Ayyar followed by showed highly tolerant to salinity at reproductive stage. The genotype NUD-3, NDRK-2008 and IR-91167-99-1-1-1-3 exhibited highly susceptible to salinity at reproductive stage. The higher magnitude of positive direct effect on grain yield/plant exerted by biological yield/plant and harvest index under control condition, under saline condition biological yield/plant followed by harvest index and spikelets/panicle showed positive and direct effect on grain yield/plant. Under field condition positive and direct effect on grain yield exerted by biological yield/plant followed by harvest index, spikelets/panicle and spikelet fertility. In the present study, the 12 genotypes of rice were grouped into four different non-overlapping clusters under saline, field and control conditions. The highest intra cluster distance was recorded for cluster IV under controlled condition, cluster II under saline condition and cluster III under field condition. Under controlled condition highest inter cluster distance recorded in cluster II and cluster IV. Under saline condition, cluster II and cluster III had highest inter cluster distance. Under field condition, the highest inter cluster distance recorded in cluster I and cluster IV. RM 10772 exhibited polymorphism in 12 rice genotypes, while RM10745 exhibited Monomorphism in 12 rice genotypes.