Identification of physiological traits at seedling stage associated with salt tolerance in wheat variety KH 65 using RILs

Abstract

Salinity is a major stress affecting production and productivity of wheat across the world. Understanding physiological traits associated with salt tolerance can help in breeding for improving wheat under salt stress. In the present investigation, physiological traits in 3rd leaf at seedling stage and grain yield at maturity were studied in a population of RILs derived from a cross between salt tolerant (Kharchia 65) and susceptible (HD 2009) cultivars under control (pH 8.2) and sodic condition (pH 9.2) in microplots. Though, HD 2009 had higher yield under control conditions, it exhibited higher reduction in yield (44.7%) under sodic stress as compared to KH 65 (9.8%). There was asignificantly lower accumulation of Na+ content and higher accumulation of K+, proline and chlorophyll content in 3rd leaf of KH 65 as compared to HD 2009 under sodic stress. Na+ content exhibited significant negative correlation (P<0.01) while K+/Na+ ratio, proline content and chlorophyll content showed significant positive correlation (P<0.01) with grain yield (GY) under sodic condition. First and second principal component analysis (PCA) explained total variation of 66.43% (PCI 50.18 % and PCII 16.25%) among different traits under sodic conditions. Na+ content made independent group with strong negative correlation with grain yield and K+/Na+ ratio while proline content and thousand grain weight (TGW) were grouped together along with GY. The study demonstrated that low Na+ concentration and high K+/Na+ ratio, proline and chlorophyll content at seedling stage are important physiological traits contributing towards yield under sodic stress. The information is useful in breeding programme of wheat for salt tolerance.