Genetic Variability and Trait Association Studies for Yield Related Traits in Bread Wheat (Triticum aestivum L.)

Abstract

The present investigation was carried out to assess genetic variability and trait association for yield and
yield-contributing traits in bread wheat (Triticum aestivum L.). A total of 296 wheat genotypes, including
292 lines from the Wheat Association Mapping Initiative (WAMI) spring wheat panel and four check
varieties, were evaluated during Rabi 2024–2025 at the Main Experiment Station, Acharya Narendra
Deva University of Agriculture and Technology, Kumarganj, Ayodhya, Uttar Pradesh. The experiment
was laid out in an Augmented Randomized Complete Block Design with six blocks. Observations were
recorded for days to anthesis, days to maturity, plant height, spike length, spikelets per spike, grains per
spike, test weight and grain yield per plant. Analysis of variance revealed significant differences among
genotypes for most of the studied traits, indicating the presence of substantial genetic variability.
Descriptive statistics showed a wide range for plant height, grains per spike, test weight and grain yield
per plant, suggesting considerable phenotypic diversity in the experimental material. The highest GCV
and PCV were recorded for grain yield per plant, followed by grains per spike, spikelets per spike, test
weight and spike length. High heritability coupled with high genetic advance was observed for grain
yield per plant, grains per spike, spikelets per spike, test weight and spike length, indicating the
predominance of additive gene action and good response to selection. Correlation analysis showed that
grain yield per plant had significant positive association with spike length, spikelets per spike, grains per
spike and test weight. Path coefficient analysis further confirmed that spike length had the highest
positive direct effect on grain yield per plant, followed by spikelets per spike, test weight and grains per
spike. Therefore, these traits may be considered as important selection criteria for improving grain yield
in bread wheat breeding programmes.