Genetic evaluation of yield and yield components at advanced generations in rapeseed (Brassica napus L.)

Three varieties of rapeseed namely Foseto, Option500 and Goliath including F2 and F3 generations (crosses among them) were planted in a complete randomized block design for evaluation of genetic variation, heritability, genetic advance and relationships between yield and its components, in experimental field of Rice and Citrus Research Institute, University of Agricultural Science and Natural Resources of Sari, Iran. The results indicated that the maximum phenotypic and genotypic variation related to the number of pod/plant and seed yield, and also their heritability in F2 and F3 generations were 94, 83 and 89, 96% including the good genetic advance in F2 and F3 generations, 33.81, 40.5 and 45.69, 53.7%, respectively. These genetic values express the role of additive effect of the genes controlling the heritability of the studied traits, so, selection of the agronomic important traits at the early generations will be effectiveness. The correlation between phenotype and genotype showed, the positive and significant relationship among seed yield, number of pod/plant, number of branch/plant, 1000 grain weight and pod length in F2 and F3 generations. The path analysis also indicated, the direct effect of the number of pod/plant in F2 and number of branch/plant in F3 generation, so these traits can be good criteria for selection at the segregating generations in rapeseed breeding pro-ram.