RELATIONSHIP BETWEEN GENETIC-DISTANCE AND HETEROSIS FOR YIELD AND MORPHOLOGICAL TRAITS IN WINTER CANOLA (BRASSICA-NAPUS L)

Genetic distance among canola cultivars was estimated through multivar iate analysis. Thirty cultivars from various sources were analyzed and clustered based upon five morphological characteristics and yield com ponents-crown diameter, number of branches plant(-1), number of pods p lant(-1), number of seeds pod(-1) and yield plant(-1) - and placed in three distinct clusters. Two cultivars from each cluster were selected as parents and 15 partial-diallel inter- and intra-cluster crosses we re made between the six selected parents and evaluated at two location s in Michigan in 1990/1991. The association between genetic distance a nd mid-parent heterosis was investigated. The correlation between gene tic distance and heterosis was positive and highly significant for see d yield, number of pods plant - 1, and number of seeds pod(-1). Cluste ring, based on yield and yield-component traits, demonstrated that int er-cluster heterosis was greater than intra-cluster heterosis in the m ajority of cases.