Selection Criteria and Genetic Variability Studies in Salinity Tolerant Rice Genotypes

Abstract

The field experiment was carried out using 72 rice genotypes at Agricultural Research Station, Kampasagar, Nalgonda district which is located at geographical co-ordinates of 16.8536 N latitude and 79.4569 longitudes. Analysis of variance revealed significant genotypic difference for all the traits studied indicating that a large amount of variability present in germplasm and there is a scope for selecting promising genotypes to develop salinity tolerant rice varieties. The values of genotypic and phenotypic coefficients of variation (GCV and PCV) were moderate for Total no. of tillers/plant (16.72 and 17.70), No. of effective tillers/plant (15.82 and 17.90) and spikelet fertility (%) (19.14 and 20.38), grain length (mm) (12.83 and 13.62) and grain breadth (15.54 and 16.01); low for days to 50% flowering (6.72 and 696). Selection for these traits would offer better scope for genotypes A close difference between phenotypic and genotypic coefficient of variation revealed that there was a little influence of environment on the expression of the character studied. Selection for these traits would offer better scope for development of these traits. High heritability coupled with high genetic advance as percent of mean was observed for all the traits except for plant height and reproductive stage salinity stage scoring indicating the preponderance of additive type of gene action for the expression of this characters and selection may be effective for improving this character. The study of simple correlation in the present investigation suggested that positive and significant assosiation of yield with number of filled grains per panicle (0.8477**), spikelet fertility (0.6621**), productive tillers (0.4107**) test weight (0.4105**) panicle length (0.2864**), plant height (0.2815**). However, it exhibited significant and negative correlation with seedling mortality (-0.9124**Present study revealed that there was good amount of genetic variability in the traits number of effective tillers per plant, panicle length, grains/panicle and test weight, selection would be more effective for developing these traits.