M. M. Majidi - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Islamic Republic of Iran.
Y. Sharafi - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Islamic Republic of Iran.
M. Jafarzadeh - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Islamic Republic of Iran.
A. Mirlohi - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Islamic Republic of Iran.

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, ۲۸ winter rapeseed cultivars were evaluated for genetic variation and relationships between ۱۱ agro-morphological characters during ۲۰۱۰ and ۲۰۱۱. 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 sense heritability estimates ranged from ۶% to ۸۷% 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 ۷۱% of the total variability, which were named ‘productivity’, ‘phenology and oil’, and ‘pod length’, respectively. According to the first factor, RGS۰۰۳, 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.

Diversity, Factor Analysis, Genetic variability, Selection