Evaluation of drought stress resistance in two cultivars of point and bush beans

Among abiotic stresses, drought is one of the most important environmental factors that limit the production of crops and sometimes reduces the average of the yield up to 50 percent. In order to investigate the effect of drought stress on some of the biochemical and physiological characteristics of bean (Phaseolus vulgaris L.), a factorialfield experiment was conducted in the form of randomized complete block design with three replications at the University of Guilan in which drought stress was applied at three levels (30, 60 and %100 (control)) of crop capacity using two cultivars including point bean (Ghaffar cultivar) and bush bean (G-18) for 12 days from three-leaf stage (V3) onward and was harvested 33 days after planting. The results of ANOVA showed that at the levels of %30 and %60 of FC, water stress led to a significant reduction in the relative water content (RWC) and a significant increase in protein, proline, malondialdehyde (MDA) and soluble carbohydrates, compared to control level. At the level of %30 of FC, the protein content and soluble sugars had a significant increase in Ghaffar cultivar compared with G-18 cultivar. Increased protein accumulation under drought stress is sometimes performed to produce nitrogen storage to be used in plant cellular metabolic processes during drought stress. Also, in drought stress of %60 of FC, Ghaffar, and G-18 cultivar showed an increase in proline content with the average of 4.19 and 2.1 mg/g fresh weight, respectively, in comparison to controls with 2.36 and 1.48 mg/g fresh weight. The results of the current study showed that Ghaffar cultivar was less affected under drought stress by using different mechanisms of water stress tolerance such as increasing proline and soluble sugars content, compared with G-18 cultivar. Since the studied characteristic in this study is suitable criteria to identify drought tolerant cultivars, according to the current results, Ghaffar cultivar was recognized as drought tolerant cultivar compared with G-18 cultivar.

کلیدواژه ها:

Physiological characteristics ، Drought stress ، Bean cultivars