STUDY OF VARIABILITY AND GENETIC DIVERGENCE IN MUSTARD (Brassica spp.)

Abstract

The field experiment was conducted with 25 mustard (Brassica sp.) genotypes at the farm division field of Hajee Mohammad Danesh Science and Technology University, Dinajpur during November-2010 to Februry-2010 to study variability and genetic diversity present among 25 mustard genotypes (Brassica sp.). Eleven quantitative characters viz. plant height, days to 50% flowering, days to maturity, number of primary branches per plant, number of secondary branches per plant, number of siliqua/plant, diameter of siliqua, length of siliqua, number of seed per pod, 100 seed weight and yield per plant were taken into consideration. The analysis of variance revealed remarkable variability among the genotypes for the characters concerned. The magnitudes of phenotypic coefficient of variations were higher than corresponding genotypic coefficients of variation. Higher genotypic as well as phenotypic coefficient of variations were computed for number of secondary branches per plant, number of siliqua /plant, number of primary branches per plant and yield per plant. Heritability estimates were higher for all the characters except number of secondary branches/plant. High heritabilities coupled with high magnitude of genetic advances were estimated for secondary branches per plant, number of siliqua /plant, number of primary branches per plant and yield per plant. Cluster analysis was used for grouping of 25 mustard (Brassica sp.) and the genotypes were belonging to six clusters. Cluster IT had maximum (13) and cluster IV, V and VI had the minimum number (2) of genotypes. The highest inter-cluster distance was observed between cluster I and IV and the lowest between cluster V and VI. Cluster II (D=4.91) have highest intra-cluster distance where lowest in cluster II (5.607). The characters plant height and number of secondary branches per plant, number of siliqua/plant had maximum contribution towards divergence among the mustard genotypes. Considering variability and diversity analysis, the genotypes, BARI-11, BARI-12, BARI-9 from cluster III for higher yield, early flowering and fruit maturity; the genotypes DAULAT and BARI-14 from cluster IV for higher number of siliqua/plant, number of secondary branches/ plant, yield/ plant might be considered as better parents for future hybridization program.