GENETIC DIVERSITY IN RAPESEED MUSTARD (Brassica rapa L.) GENOTYPES

Abstract

An experiment was carried out with 51 genotypes of Braswica rapa including two commercially cultivated varieties as cheeks to study their inter-genotypic variability, con-elation, path co-efficient and genetic divergence considering 10 different morphological characters at the experimental farm of SAU, Dhaka during November 2012 to February 2013. Significant variation was observed among all the genotypes for all the characters studied except thousand seed weight. High CCV value was observed for number of secondary branches per plant. High heritability values along with low genetic advance in percent of mean were obtained for number of seeds per siliqua, seed yield per plant, number of secondary branches per plant and days to 50% [lowering. Highly significant positive association of seed yield per plant was observed with number of siliqua per plant, thousand seed weight,numbcr of seeds per siliqua, number of primary branches per plant.Path analysis showed that , yield per plant had the highest direct effect on number of siliqua per plant, number of seeds per siliqua and thousand seed weight. By using different niultivariate analysis techniques all the genotypes were grouped into five cluster, PCA, PCO. C\'A analysis gave almost similar result. Cluster ill had maximum (19) and Cluster I had minimum (2) number of genotypes. The highest inter-cluster distance was observed between cluster I and cluster V (10.43). The highest intra cluster distance was cluster V (0.459). The lowest intra cluster distance was cluster 1 (0.0). Moderate or intermediate inter cluster distance was found between cluster 1 and cluster IV (4.47) and cluster III and cluster V (4.86). Considering the magnitude of genetic distance, contribution of different characters towards the total divergence, magnitude of cluster mean for different characters and field performance the genotypes 0-35 and G-47 from cluster Ill and CI, 0-I8. 0-41 and (i-46 from cluster V would be suitable for highest yield per plant for future hybridization programme.lnvolvement of such diverse genotypes in crossing program produces desirable segregates. So, divergent genotypes are recommended to use as parent in hybridization program.