Assessment of genetic divergence in thirty-five genotypes of oilseed Brassica species

Abstract

The experimental material comprised of 35 genotypes including 20 F2s/F3s and 15 parents of different Brassica species. The Mahalanobis’s D2 statistics of genetic divergence indicated the presence of wider genetic diversity among genotypes in both year 2015-16 and 2016-17. All 35 genotypes were grouped into six clusters in 2015-16 and five clusters in 2016-17. Highest number of genotypes were accommodated in C I followed by cluster II during 2015-16. While in 2016-17 cluster I was the largest with 31 genotypes. The inter and intra cluster distance of the 35 genotypes showed wide range of estimation in both years. The highest inter-cluster distance was observed between cluster II & IV followed by cluster II & V and cluster III & VI in 2015-16. In 2016-17 the cluster II & V showed maximum inter-cluster distance followed by cluster III & IV and cluster IV & V. The maximum intra-cluster distance was shown by cluster I. The relative contribution of each character towards divergence was maximum for oil yield per plant in 2015-16 followed by seeds per siliqua, oil content, test weight, plant height and days to maturity. While in 2016-17, test weight contributed maximum towards divergence followed by oil yield per plant, oil content, Seeds per siliqua, secondary branches and siliqua length.