Multivariate Analysis of Genetic Variation in Winter Rapeseed (Brassica napus L.) Cultivars
J. Agr. Sci. Tech
Designing breeding programs for winter rapeseed (Brassica napus L.) cultivars with improved seed and oil yields requires information about the genetic variability of traits. In this study, 28 winter rapeseed cultivars were evaluated for genetic variation and relationships between 11 agro-morphological characters during 2010 and 2011. Cultivars and cultivar × year interaction showed significant variation for all studied traits. Genotypic coefficients of variation indicated that yield, number of
... t yield, number of branches per plant, and plant height had the highest variation. Broad sense heritability estimates ranged from 6% to 87% for seed yield and pod length, respectively. Positive correlation was found between seed yield with number of pods per plant, number of branches per plant, days to flowering, and days to ripening. The result of factor analysis showed three independent factors that explained 71% of the total variability, which were named 'productivity', 'phenology and oil', and 'pod length', respectively. According to the first factor, RGS003, Opera, and Hayola were identified as high seed yielding cultivars. Based on all three factors, Lilian, Licord, and Ella were identified as the best cultivars concerning seed yield and oil content.