Character association and stress indices for yield components in Saltol introgressed backcross inbred lines of rice (Oryza sativa L.)

Abstract

Correlation, path coefficient and stress indices for yield and its components were studied in 32 Saltol introgressed backcross inbred lines (BIL) of rice along with a tolerant parent FL 478, susceptible check IR 29 and two recurrent parents viz., ADT 37 and CR 1009 Sub1 under normal and saline environments during rabi, 2016. Grain yield per plant showed positive significant association with all traits except 100 grain weight under normal environment and it showed positive significant association with all traits except panicle length, spikelet fertility and 100 grain weight under saline condition. The direct positive effects of number of tillers per plant, number of productive tillers per plant, number of filled grains per panicle and spikelet fertility on grain yield under normal and saline environment indicating direct selection of these traits would be effective for increasing grain yield. Under salinity, negative and significant association was shown by stress susceptibility index (SSI) and grain yield in contrast to positive and significant association shown by stress tolerance index (STI) and grain yield. These associations could be useful in identifying salt tolerant and sensitive high yielding genotypes. The lines viz., BIL 108, BIL 752, BIL 1101, BIL 1079, BIL 1094 and BIL 1095 had exhibited higher values of stress tolerance index in salinity.