Genetic Variation of Morpho-physiological Characters in Wheat

Abstract

Wheat (Triticum aestivum L.) is a globally important staple crop, yet its production is challenged by climate variability, soil constraints, and genetic limitations. Despite extensive breeding efforts, limited studies have comprehensively analyzed morpho-physiological traits across diverse wheat genotypes under agroecological zone (AEZ-9) conditions in Bangladesh. Therefore, this study was conducted with 17 wheat genotypes following a Randomized Complete Block Design (RCBD) with three replications at the Field Laboratory of the Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh, from December 2023 to April 2024 to assess genetic variability, heritability, expected genetic advance, and interrelationships among key morpho-physiological traits. Statistical analyses conducted by R programming revealed that significant genetic variation among the genotypes for all studied traits. High heritability coupled with high genetic advance was observed for grain-filling rate, 1000-grain weight, and yield per plant, indicating strong additive gene effects and potential for selection. Correlation analysis showed that grain-filling rate, spike number, and days to maturity were positively associated with yield, suggesting their importance in wheat improvement programs. Path coefficient analysis further confirmed the direct contribution of grain-filling rate to yield. These findings underscore the significance of grain-filling rate and spike number as key selection criteria for improving wheat yield under AEZ-9 conditions. Future breeding programs should prioritize these traits to develop high-yielding, stress-tolerant wheat varieties.