Genetic Analysis for Grain Yield and Yield Related Traits in Bread Wheat (Triticum aestivum L.)

Abstract

Understanding the genetic basis and evolutionary history of drought-tolerant wheat genotypes was the principal aim of this investigation. Twenty-seven wheat genotypes were assessed under normal and drought conditions using a Randomized Complete Block Design (RCBD). Line × Tester analysis was employed to study combining ability, heritability and gene action in a plot size of 12.3 m². The experiment comprised four replications, two under normal irrigation and two under drought stress. Drought-tolerant genotypes Fareed-06, Ghazi-19, Sadiq-21, Bwp-79, Nishan-21 and Jauhar-16 were used as lines, while three drought-susceptible genotypes (181601, NR-535 and NR-179) served as testers. Eighteen F₁ crosses were developed from these nine genotypes. Analysis of variance revealed statistically significant differences among crosses and genotypes for all parameters examined in both environments. Under normal conditions, significant differences were detected among lines for plant height, grains spike⁻¹ and biological yield plant⁻¹. Under water stress, significance was confined to grains spike⁻¹. Fareed-06 demonstrated maximum General Combining Ability (GCA) for tillers plant⁻¹, biological yield plant⁻¹ and grain yield plant⁻¹ in both environments. Cross combinations Jauhar-16 × 181601 and Bwp-79 × NR-535 proved superior in both conditions. Non-additive gene action was predominant for all traits except grains spike⁻¹ under both environments. Plant height, flag leaf area, tillers plant⁻¹, grains spike⁻¹, and biological yield plant⁻¹ exhibited high broad-sense heritability (h²). Genotypes Fareed-06 and 181601, together with crosses Jauhar-16 × 181601 and Bwp-79 × NR-535, are recommended for future drought-tolerance wheat breeding programs.