Evaluation of Genetic Diversity in Indian and Exotic Brassica Juncea Genotypes through Phenotypic

Abstract

Background: Rapeseed-mustard stands as one of India's key oilseed crops, yet its genetic diversity remains largely unexplored. A comprehensive understanding of this aspect is crucial for effectively harnessing genotypes in crop enhancement endeavors.

Methods: This study aimed to assess the genetic diversity among 95 diverse genotypes of Brassica juncea (L.) grown in paired rows of 4 m length with a spacing of 30 x 10-15 cm (row × plant). Data were collected on 11 distinct agro-morphological traits.

Results: The 95 genotypes were categorized into five distinct clusters based on Manhattan dissimilarity coefficients. Clusters V and IV contained the highest number of genotypes (35 and 23 genotypes, respectively), while cluster II had the fewest (three genotypes). Manhattan dissimilarity coefficients ranged from 0.741 to 8.299. The largest dissimilarity (8.299) was observed between genotypes DRMRIJ-15-133 and M 62. Cluster III exhibited medium plant height with medium early maturity, while cluster I displayed the highest mean values for most agro-morphological traits. This study underscores the significant genetic diversity among genotypes, offering potential utility in future breeding programs aimed at developing mustard cultivars and managing germplasm effectively.