Multivariate Analysis of Genetic Diversity in Brassica species for Yield and Agronomical Traits

Abstract

Brassica species is a vital oilseed crop group in India, contributing significantly to edible oil production owing to its adaptability to diverse agro-climatic conditions. Despite its economic importance, productivity remains constrained by an array of biotic and abiotic stresses, emphasizing the need for genetic improvement through the identification of diverse and high-yielding genotypes. The present investigation was undertaken during the Rabi 2024 at the Research Farm, ZARS, Morena, RVSKVV, Gwalior, MP, to assess the genetic divergence among 73 Brassica genotypes employing Mahalanobis D² statistics and Principal Component Analysis. The experiment was laid out in a randomized block design with two replications, and observations were recorded on 16 quantitative traits. Mahalanobis D² analysis revealed the formation of six distinct clusters, indicated presence of considerable genetic variability among the genotypes. Genotypic distribution indicated maximum aggregation in Cluster I (36 genotypes), followed by Cluster III (15), Cluster II (10) and Cluster V (9), while Cluster IV (2) and Cluster VI (1) exhibited minimal representation. Cluster III exhibited the highest seed yield (24.83g), biological yield (52.53 g) and harvest index (47.96%), while cluster IV displayed early flowering and maturity. The highest inter-cluster distance (203.42) was recorded between clusters III and IV, suggested their potential use in hybridization to exploit heterosis. The first four principal components contributed 78.60% of the total variation, with PC1 alone accounting for 37.64%, primarily influenced by yield and phenological traits in PCA analysis. The study identified diverse genotypes such as Banarasi Rai, GSC-7, Giriraj, RH-406, PC-6 and China Cabbage, which can serve as potential parents in breeding programmes aimed to enhance yield and stress tolerance.