Abstract

Salinity stress is a major threat to food production, and its intensity is increasing gradually. It causes ion toxicity, oxidative stress and osmotic stress, resulting in decreased vegetative growth and yield of wheat (Triticum aestivum L.). In plant breeding, genetic variability is a basic requirement to develop cultivar that performs best under different climatic conditions. In this study, eleven females and four males were assessed for morphological, physiological and biochemical traits using North Carolina Mating Design II (NCM-II). The 44 wheat crosses along with 15 parents were planted under normal (0.9 dS m-1) and salt affected field (10.2 dS m-1). The analysis of variance (ANOVA) revealed highly significant differences among genotypes for most of the attributes. Treatments had substantial effect on the expression of all the traits except for plant height, grain weight/spike and relative water content. Interaction of genotypes with treatments showed highly significant differences for all the attributes except for plant height, grains/spike and photosynthetic rate. General combing ability revealed that parents LLR-20, 9459, LLR-14, STW-118, Chenab-2000 and Millat-11 are the best general combiners presenting additive gene action. Cross combinations LLR-20× LLR-14, TW-161× Millat-11, 9459 × Millat-11, Ujala-16× Millat-11, TOB-66 × Millat-11 and Galaxy-11 × Chenab-2000 indicated significant specific combing ability effects which exhibited non-additive gene action. Among 14 Simple Sequence Repeat (SSR) markers, gwm410 marker was the most informative having highest PIC value (0.37) and high genetic diversity (0.50). Cluster analysis showed that maximum genetic diversity (0.54) was observed between Chenab-2000 and TW-161 followed by TOB-66 and STW-118 (0.44). These findings suggested that considering physio-morphological, biochemical and molecular characterization, genetically diverse parents might be used as crossing parents to develop high yielding varieties in future breeding programs to uncover the salinity responsive genes in wheat.