Genetic diversity analysis in Indian mustard (Brassica juncea L. Czern and Coss) genotypes using agro-morphological parameters

Abstract

An experiment was conducted using 45 genotypes including local cultivars, advanced lines and notified varieties of Indian mustard for genetic diversity analysis through Mahalanobis’s D2 method. The study was conducted in RBD design with 3 replications having plot size of 1.5 x 5 m2 and row spacing of 30 x 10 cm. Data were recorded on 14 different agro-morphological characters viz. days to 50% flowering, days to maturity, plant height (cm), number of primary and secondary branches per plant, main shoot length (cm), leaf area index, root width and length ratio, number of siliqua per plant, siliqua length (cm), number of seeds per siliqua, seed yield per plant (g), 1000 seed weight (g) and oil content (%). The analysis of variance revealed significant differences among the genotypes for all characters under study. The genotypes were grouped into 7 clusters using Tocher’s method, with cluster I containing maximum genotypes (18 genotypes) followed by cluster III (9 genotypes), cluster IV (8 genotypes), cluster II (6 genotypes), cluster VI (2 genotypes) while cluster V and VII with single genotype each. Root width and length ratio, siliqua per plant, main shoot length and 1000 seed weight were the major contributors for genetic diversity among the genotypes with 23%, 21.80%, 21.32% and 20.51% respectively. The cluster IV exhibited maximum intra-cluster distance followed by cluster VI (844.272) while maximum inter-cluster distance was found between cluster V and VII (7273.532). Selection of diverse genotype containing desirable characters from the cluster and utilizing in hybridization programme will likely produce trangressive segregants and heterotic F1s.

Keywords

• brassica juncea l.
• genetic divergence
• mahalanobis’s d2 analysis
• cluster analysis