Journal of Crop Breeding

In order to investigate the relationships between major agronomy traits and grain yield in rapeseed, two apetalous flowers (Hylite201) and petalled (Hyola401) rapeseed cultivars were planted in three plant densities and two planting patterns was carried out in a split plot-factorial design based on randomized complete block design with three replications at Rice Research Institute of Iran at Rasht during 2005-2006 cropping seasons. Yield and yield component traits were measured in all treatment. Results showed that there were significant differences between the measured traits which denoted a high rate of variation in rapeseed cultivars. Yield had a significant positive correlation with number of pods per plant, pod length, number of seeds per pod and number of lateral branches in each of the conditions of pattern, cultivars type and plant density, while had a significant negative correlation with plant height. The correlation between yield and yield component was different in various conditions that showed the effect of conditions. Stepwise regression analysis in each condition indicated that special trait entered to the model as effective traits to explain total grain yield variation. Results of path coefficient analysis at different conditions also showed that number of pods per plant in most conditions of studied had the highest direct effect and the lowest indirect effect through other trait on grain yield, so considered the major traits in grain yield enhancement in the most conditions.