Identification of Effective Traits on Grain Yield Improvement in Bean Cultivars (Phaseolus vulgaris L.) Under Different Moisture Stress Conditions

In order to identify the most important effective traits on grain yield and to evaluated the genetic diversity of 9 bean cultivars, three separated experiments, were conducted at three conditions of normal, moisture stress before podding and moisture stress after podding, based on randomized complete block design with three replications. Results showed that the difference between the cultivars was significant for all traits, except seed number per plant. Result also indicate that the cultivars had different genetic potential in different moisture conditions. The maximum grain yield belonged to Daneshkade and Dorsa cultivars and the minimum to Sayad and Goli in three conditions. Total grain yield was significantly reduced through the transition from non-moisture stress to moisture stress condition. Indicating the significant effect of moisture stress on grain yield. In fact, the effect of different moisture conditions was significant on the majority of traits, except the traits of days to 50% podding, days from planting to maturity and harvest index. Correlation results indicated that the traits of pod weight per plant, biological yield, pods number per plant, seed number per plant, harvest index, 100-kernel weight and seed filling period had significant and positive correlation with grain yield. The results of stepwise regression showed that the traits of pod weight per plant, harvest index, biological yield and number of pods per plant were the most important effective traits on economic yield. The highest genotypic and phenotypic variation coefficient belonged to pods per plant in all conditions.