Genetic analysis of salt tolerance in early growth stages of rapeseed (Brassica napus L.) genotypes

Abstract

Genetic parameters for different characteristics related to salinity tolerance were estimated using 8 x 8 diallel crosses in rapeseed (8. napus). Salt stress was induced by adding incremental levels of NaCI to Hoaglands solution in a sand culture until electrical conductivity of 12.9dSm-1 was attained. Analysis of variance revealed significant general and specific combining ability mean squares for all studied characteristics, indicating the involvement of both additive and non-additive gene actions in the inheritance of 20'2 characters. High ratios of 2 gca 2 and high (2 O'gca + O'sca ) narrow-sense heritability estimates were observed for Ca2+, K+, Na+, K+/Na+, Ca2+lNa+, and stress tolerance index (TOL), indicating the prime importance of additive effects in their genetic control. Significant positive correlations were observed between shoot dry weight and Ca2+lNa+ (0.531**), and K+lNa+ (0.562**). The results revealed that the parents BL2, Ceres, and Shiralee and the crosses Falcon x BL2, BL2 x Ceres and Ceres x Shiralee were superior to perform effective selection for salinity tolerance in rapeseed.