Abstract

Eight rapeseed cultivars were studied for variability, heritability and correlation analysis of seed yield and yield components in Southern Iran for two years (2009 and 2010). These genotypes were planted in field arranged on randomized completely blocks design with three replications at the Research Centre of Islamic Azad University of Firoozabad, 95 km of Shiraz. The studied traits were days from emergence to flowering, days from emergence to physiological maturity, plant height, pod length, pods number on main stem, pods per plant, seeds per pod, 1000-seed weight, harvest index and grain yield. Results showed that genetic variability of genotypes was significant for all traits except for pod length and seeds per pod. Interaction between year and genotype was highly significant for seeds per pod. Based on broad sense heritability of traits and correlation between grain yields and other traits, pods per plant, 1000-grain weight and pods on main stem had high direct effect on grain yield in both years. Therefore, selection for increasing grain yield through these traits might be more successful. Selection of desirable varieties to increase grain yield is based on yield component. Based on the results of cluster analysis, the genotypes were grouped into four clusters irrespective of the geographical divergence. Therefore, Modena and Sarigol cultivars were the best resources to increase grain yield during both years and Okapi cultivar was the worst.

Key words: Rapeseed, heritability, correlation, grain yield.