Evaluation of Germplasm for Reproductive Stage Salinity Tolerance in Rice (Oryza sativa L.)

Abstract

The current study was carried out to identify salt tolerant genotypes by screening 76 rice germplasm at reproductive stage salinity stress. The test entries were subjected to salt stress under field conditions and salinity was noted at different intervals of crop growth period i.e., 30 and 67 days after sowing and at the time of harvesting with the pH value of 5.4 and electrical conductivity of 4.3 dSm-1, 5.3 dSm-1and 7.2 dSm-1 respectively. The characters namely, salinity score, days to 50 percent flowering, plant height, panicle length, productive tillers/plant, number of filled grains/panicle, total number of grains/panicle, spikelet fertility and grain yield/plant were studied under saline conditions. Variability, heritability and genetic advance as percent of mean showed high genotypic and phenotypic coefficient of variation for grain yield plant-1indicating the presence of considerable amount of variation among the genotypes for potential yield improvement through selection. The trait grain yield per plant had high heritability coupled with high genetic advance as percent of mean indicating that it is regulated by additive gene action and therefore selection could be practiced based on phenotypic performance. Association studies under saline conditions, revealed favorable and significant correlation of grain yield per plant with days to 50% flowering, panicle length, plant height, total number of grains per panicle, number of filled grains per panicle and productive tillers per plant whereas, spikelet fertility and plant height on the other hand, recorded negative non-significant correlation, indicating the undesirable causes of salinity on plant growth and yield potential.