Genetics of salt tolerance in rice

Abstract

Salt tolerance studies were conducted under controlled conditions by using solution and pot culture techniques at the International Rice Research Institute. Varieties Nona Bokra and Pokkali (tolerant), Damodar and Jhona 349 (moderately tolerant), and IR28 and IR35657-33-2 (sensitive) were selected for genetic analysis of traits under salinization (EC 12 dS/m) at the seedling and reproductive stages. Both additive and dominance effects were important in the inheritance of all the traits studied. Shoot length, Na and Ca content in the shoots, and dry weight of shoots and roots showed significant additive effects with a high degree of heritability. Genes controlling Na and Ca levels in shoots were found to be partially dominant. At least three groups of genes were found to be involved in the inheritance of Na and Ca levels at the seedling stage. Highly significant additive effects were also observed for plant height and yield/plant, with high heritability values. Selection on the basis of shoot length, Na level in the shoots, dry weight of shoots and roots, plant height, and yield/plant showing predominance of additive effects and high heritability values could lead to the development of salt-tolerant cultivars.