Genetic Analysis of Yield and Yield Attributing Traits in Brassica napus Using F2 Progenies of Diallel Crosses

Background and Objective: Rapeseed (Brassica napus L.) is a leading oilseed crop in Bangladesh but its yield is almost lower comparing to the others rapeseed growing countries in the world.In the present study, diallel analysis in rapeseed was carried out to evaluate potential lines, hybrids and nature of gene action involved in the inheritance regarding yield and yield attributing traits. Materials and Methods:A total number of 21plant materials were used in this experiment whereas six were used as parents and 15 were as F 2 segregating generations.The experiment was laid out in Randomized Complete Block Design (RCBD) with 3 replications.All data were analyzed by using one way analysis of variance (ANOVA) with the help of computer software package MSTAT-C program, followed by Duncan multiple range test.The combining ability analysis was performed using mean values according to Griffing's Model I and Method II.Results: Analysis of combining ability showed highly significant GCA (general combining ability) and SCA (specific combining ability) effects for the studied traits.Based on GCA, out of 15 crosses, the best general combiners were Nap-9908 for number of siliquae/plant, seed/siliqua and seed yield/plant.The higher magnitude of GCA variance was observed than that of SCA variance for all the studied characters except days to 50% flowering and number of secondary branches/plant.Similarly, based on SCA, the best combiners were Nap-9905×Nap-205 for number of primary branches and seed yield/plant, Nap-9901×Nap-205 for secondary branches, siliqua length and seeds/siliqua and Nap-9908×Nap-9901 for number of siliqua/plant could be utilize in future rapeseed breeding program.In the Vr-Wr graph, the partial dominance was observed for secondary branches/plant and seed yield/plant but except the two characters, all other characters showed over dominance.The graphical analysis also indicates wide genetic diversity among the parents.Conclusion: After assessing all the characters, Nap-9908 is the best general combiner and Nap-9905×Nap-205 is the best cross combiner and could be used as genetic materials for the higher rapeseed production in Bangladesh.