Multivariate Analysis of Genetic Variation in Winter Rapeseed ( Brassica napus L . ) Cultivars

Abstract

Designing breeding programs for winter rapeseed ( Brassica napus L . ) cultivars with improved seed and oil yields requires information a bout the genetic variability of traits. In this study, 28 winter rapeseed cultivars were ev aluated for genetic variation and relationships between 11 agro-morphological charact ers 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 branches per plant, and plant height had the highest variation. Broad s ense heritability estimates ranged from 6% to 87% for seed yield and pod length, respective ly. Positive correlation was found between seed yield with number of pods per plant, n umber of branches per plant, days to flowering, and days to ripening. The result of fact or 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 yiel ding cultivars. Based on all three factors, Lilian, Licord, and Ella were identified a s the best cultivars concerning seed yield and oil content. Keyword : Diversity, Factor analysis, Genetic variability, Selection.