COMPARATIVE ASSESSMENT OF GENETIC DIVERSITY BETWEEN BRASSICA NAPUS AND BRASSICA JUNCEA BASED ON PHENOTYPIC TRAITS

Abstract

Rapeseed and mustard crops’ extensive promotion for crop diversification and their potential to favorably respond to breeding programs depends on their existing nature and the magnitude of genetic variability. Therefore, the progressive research sought to estimate the genetic diversity of 40 genotypes of Brassica napus (20) and Brassica juncea (20) based on phenotypic characters. The material, grown in randomized complete block design, had three replications during winter 2020– 2021. The mean square from analysis of variance demonstrated significant differences for all the parameters among examined varieties, indicating that utilized material contained sufficient genetic variability. Regarding average performance, two mustard genotypes, Dhoom-I and Anmol Raya, performed better for seed yield plant-1 and can undergo assessment in upcoming breeding programs for enhancing seed yield. Meanwhile, high heritability occurred in oil content, silique length, 1000-seed index weight, and plant height. Diversity analysis, cluster mean, and total divergence contribution revealed maximum differences for various traits and possessed noteworthy sources for future breeding programs. The magnitude of cluster distance indicated that cluster VI comprised two mustard genotypes (Early Raya and Sindh Raya) and cluster IV consisted of three rapeseed genotypes (Rohi Sarson, hyola-401, and Kn-277), demonstrating that maximum distance is more diverse and helpful for upcoming heterotic recombination. Comparing genetic variation between rapeseed and mustard genotypes showed that rapeseed genotypes displayed more genetic variability in the first three components of PCA than its counterpart, yet expressing that mustard genotypes also have enormous valuable genetic resources. Similarly, genotypes Rohi Sarson, hyola-401, and Kn-277 resulted in the highest genotypic scores in three-dimensional graphs; hence, these genotypes are more diverse and can benefit future hybridization programs.