Genetic Variability and Interrelationships among Quantitative Traits in Rapeseed (Brassica napus l.) Advanced Lines

Abstract

Improvement of the new rapeseed (Brassica napus L.) cultivars requires efficient tools to monitor traits relationship in a breeding program. Thirty six rapeseed genotypes were evaluated based on randomized complete block design with three replications at Baykola Agricultural Research Station during 2010-11 and 2011-12 growing seasons. Significant genotypes effects were exhibited for phenological traits, plant height, yield components, seed and oil yields, indicating significant genetic differences among the genotypes. Broad sense heritability values were greater for days to flowering (0.98), pods per plant (0.71) and seeds per pod (0.77), indicating that these traits are controlled mainly by genetic effects and therefore selection of these traits may be effective for improving seed yield. Pods per plant and seeds per pod were significant positive correlated with seed yield and the results of stepwise regression analysis indicated that these traits explained 73% of total yield variation. On the basis of cluster analysis, all the genotypes were classified in three groups, and the group with high mean values of plant height, pods per plant and seeds per pod had also high mean values of seed and oil yields.