VARIABILITY, CHARACTER ASSOCIATION AND DIVERGENCE IN RAPESEED ADVANCED LINES

Abstract

A fleld experiment was conducted with 33 genotypes of IJi-cissica rcipa including three commercially cultivated varieties as checks to study their inter-genotypic variability: correlation, path coefficient and genetic diversity considering 9 different morphological characters at the experimental farm of Shcr-e-Bangla Agricultural University. Dhaka during October, 2011 to February, 2012. The genotypes were found to differ significantly for all the characters studied. 6-9 showed best result in term of early maturity and higher yield per plant than check varieties. 0-6: 0-30: 027; 0-15 and 6-12 also gave higher yield with early maturity. The characters plant height and number of siliquae per plant were highly influenced by the environment whereas, number of primary branches per plant, number of seeds per siliqua, siliqua length, 1000-seed weight and seed yield per plant influenced least. Moreover, the number of primary branches per plant. 1000-seed weight and seed yield per plant showed moderate broad sense heritability while number of siliquae per plant exhibited the highest heritability followed by days to maturity, number of secondary branches per plant, siliqua length, number of seeds per siliqua and plant height. The significant positive correlation with seed yield per plant was found in number of primary branches per plant and ntnnber of secondary branches per plant and significant negative correlation with number of seeds per siliqua. However, the highest significant positive correlation was found between number of siliquae per plant and seed yield per plant. Path coefficient analysis showed that the number of siliquae per plant had maximum positive direct effect on seed yield followed by plant height, number of primary branches per plant, 1000-seed weight, days to maturity and number of secondary branches per plant. Number of siliquae per plant. number of primary branches per plant and number of secondary branches per plant were the most important contributors to seed yield per plant which cotild be taken in consideration for future hybridization program. Different multivariate analysis techniques were used to classify 33 Arcessica rapcz genotypes. The genotypes were grouped into five clusters. The highest inter-cluster distance was observed between clusters Ill and V whereas the maximum intra-cluster distance was found in cluster 1. Therefore, the genotypes belonging to cluster T and cluster V. cluster 111 and cluster V and cluster 111 and cluster IV have been selected for future hybridization program. The role of number of siliquae per plant in both the vectors were important components for genetic divergence in these materials. Considering group distance and other agronomic perfhrmance the inter-genotypie crosses between 6-27 and 0-31, (1-26 and 0-27, 0-27 and 0-32, (i-30 and (1-31, 0-20 and 0-33. (1-20 and (1-33 might be suitable choice for future hybridization program.