Estimation of Genetic Diversity among Bread Wheat (Triticum aestivum L. em. Thell) Genotypes

Abstract

Triticum aestivum L. em. Thell, known as bread wheat, is a vital staple crop globally, contributing significantly to caloric and protein intake. Its hexaploid nature, comprising three genomes (AA, BB, DD), resulted from natural hybridization, enhancing its agricultural significance. The advent of high-yielding cultivars during the Green Revolution drastically increased wheat yields, and its adaptability and self-pollinating characteristics further solidified its importance in food production. Genetic diversity within Triticum aestivum is crucial for improving traits such as stress tolerance and yield. This study highlights the necessity of estimating genetic variability among wheat genotypes, utilizing 24 genotypes. The study assesses the genetic parameters and diversity of various morpho-physiological traits in bread wheat genotypes, focusing on their variability and potential for genetic improvement. Key genetic parameters including the coefficient of variation (CV), genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), and genetic advance as a percentage of mean (GAM) were estimated for traits such as days to heading, plant height, peduncle length, and grain yield. Days to heading exhibited low variability, while plant height showed considerable genetic variation, indicating a good potential for improvement. The wheat genotypes were grouped into five distinct clusters based on Mahalanobis divergence and Tocher's method, revealing significant genetic diversity. Cluster I, comprising eighteen genotypes, displayed the highest intra-cluster distance, while Clusters III and V showed the greatest inter-cluster distance. Trait analysis across clusters highlighted variations in days to heading, plant height, grain yield, and other traits, emphasizing the genetic diversity and potential for selective breeding in wheat.