Correlation and Path Coefficient Analysis of Yield, Morpho-Physiological and Quality Traits in Wheat (Triticum aestivum L.) Genotypes

Problem: Understanding the intricate interactions between yield, morphophysiological, and quality variables is critical for developing effective selection techniques in wheat (Triticum aestivum L.) breeding. Approach: This two-year study (2023-2025) investigated these connections by evaluating 43 different wheat genotypes in ideal (Talwandi Sabo, 2023-24) and late-sown heat stress (Ongole, 2024-25) field conditions, with quality attributes assessed through laboratory analysis. Correlation coefficient analysis and path analysis were used to assess the nature and magnitude of relationships, as well as the direct and indirect contributions to grain yield and quality. Findings: All of the investigated traits showed significant genotypic variance. Under ideal conditions, grain yield per plot had a high positive genotypic correlation with biological yield per plot (rg =0.833**) and test weight (rg =0.213**), with biological yield per plot having a very substantial positive direct effect (1.3183) on grain yield. In contrast, days to maturity exhibited a high negative genotypic connection with yield (rg = -0.523**). Under heat stress, grain yield per plot was strongly and positively correlated with the number of grains per spike (rg =0.802**), grain weight per spike (rg =0.803**), and grain yield per plant (rg =0.733**); path analysis revealed that grain weight per spike had the largest positive direct effect (2.5916) on yield under these conditions. Protein content had a limited direct link with grain yield but was impacted by other morpho-physiological variables. Seedling dry weight, a measure of early vigor, had a substantial positive relationship with eventual plant biomass. Conclusion: These findings demonstrate that qualities such as biological yield and test weight are important for selection under ideal conditions, but spike components (grains per spike, grain weight per spike) and effective heat escape mechanisms (e.g., improved phenology) are vital under heat stress. Path analysis successfully identified features having the greatest direct influence on production.