Abstract
Field experiments were conducted at the Student Instructional Farm of Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya, during the Rabi seasons of 2023-24 and 2024-25 to examine associations among grain yield, yield-attributing traits, and grain zinc and iron concentrations in 50 biofortified wheat lines with three checks, using an augmented design. Correlation analysis showed that days to 50% flowering was positively associated with spike length but negatively associated with biological yield and grain yield. Days to maturity was positively associated with plant height and negatively associated with harvest index and grain yield. Plant height was positively related to peduncle length, grain weight per spike, and test weight, but negatively related to tiller traits. Spikelets per spike, grains per spike, biological yield, and harvest index showed significant positive associations with grain yield. Grain iron concentration was positively associated with grains per spike, whereas zinc concentration was positively associated with peduncle length. Phenotypic path coefficient analysis indicated that harvest index and biological yield had the largest direct positive effects on grain yield. The negative associations of days to 50% flowering and days to maturity with grain yield were mainly attributable to indirect effects through biological yield and harvest index, while the direct effects of most other traits were comparatively small. These results identify harvest index and biological yield as the principal direct contributors to grain yield within the evaluated biofortified wheat material, with other traits contributing mainly through indirect associations.