Correlation and Path Coefficient Analysis for Grain Yield and Its Attributes in F1 and F2 Generations of Bread Wheat (Triticum aestivum L.) under Normal and Late-Sown (Heat Stress) Conditions
Vaibhav Chauhan *
Department of Genetics and Plant Breeding, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India.
Sarvendra Kumar
Department of Genetics and Plant Breeding, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India.
Vijay Kumar Yadav
Department of Genetics and Plant Breeding, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India.
Som Veer Singh
Department of Genetics and Plant Breeding, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India.
C. L. Maurya
Department of Seed Science and Technology, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
Correlation and path coefficient analyses divide the relationships between grain yield and its component traits into direct and indirect effects, thereby facilitating the selection of superior genotypes, particularly under terminal heat stress. Assessing the association of grain yield with its component traits under contrasting sowing conditions may support selection in bread wheat (Triticum aestivum L.). This study examined genotypic and phenotypic correlations and the direct and indirect effects of yield-related and physiological traits in F₁ and F₂ generations. Nineteen parents (14 lines and 5 testers) were used to develop 70 F1s and 70 F2s through line × tester mating (159 treatments) and were evaluated in a randomised block design with three replications at Nawabganj Farm, C.S. Azad University of Agriculture and Technology, Kanpur (U.P.), during the 2024-25 Rabi season under normal (15-25 November) and late (25-30 December) sowing environments. Eighteen characters were assessed at the genotypic and phenotypic levels. Biological yield per plant had the highest positive and highly significant genotypic correlation with grain yield per plant in both F1 and F2 generations under both normal and late-sown conditions, while harvest index also showed highly significant positive correlations with grain yield. Days to 50% heading were negatively correlated with grain yield in late F1, normal F2 and late F2. Under late sowing, highly significant positive associations of grain yield with proline content and pollen viability were observed in F1 and F2 generations, and canopy temperature depression also showed a highly significant positive association. Genotypic path analysis revealed that biological yield had the highest positive direct effect on grain yield, while harvest index also showed a positive direct effect under both sowing conditions and in both generations. Therefore, biological yield, harvest index and tillering capacity along with earliness and heat-responsive physiological traits should be considered for wheat improvement.
Keywords: Wheat, grain yield, correlation, path coefficient, heat stress, late sowing