Screening of beans (Phaseolus vulgarisL.) genotypes for drought tolerance

Abstract

Drought is an important factor limiting crop yield and food insecurity globally. Sixty- percent of the bean production areas are prone to drought and subsequently result in eighty-percent of yield reduction. It is emerging as a rising threat to farming communities in Bhutan. Limited studies on crop drought tolerance done in Bhutan. Six bean genotypes (Orey serbu, Orey regtang, Orey brokchilu, Yadhipa orey, Kerongree orey, Brokopali) chose to ascertain drought tolerance. The study was a factorial experiment with Completely Randomized Design (CRD) with six treatments and three replications. Genotypes were subjected to drought stress after 50% flowering till the start of pod formation. The drought condition induced for ten days during the pod formation and the irrigation resumed till harvesting. Means of water-stressed genotypes compared to their corresponding non- stressed with an All-pairwise comparison using the Bonferroni test at the significant level p<.05. The growth (leaf area, relative water content, root length, shoot weight, maturity) and yield parameters (the number of pods, pod length, the number of seeds number per pod, seed weight) determined during the time of harvest. There were significant differences (p<.05) in all the parameters measured under stress and non-stress conditions. Water-stress decreases plant growth and development of all the bean genotypes. With regards to drought susceptibility index (DSI), Orey serbu(1), Orey regtang(1), Yadhipa orey(1), and Kerongree orey(1) had the lowest DSI value. The lesser the susceptible indices, the greater is the tolerance level to the drought and vice versa.

Are Traditional Lima Bean (Phaseolus lunatus L.) Landraces Valuable to Cope with Climate Change? Effects of Drought on Growth and Biochemical Stress Markers

“…Khalil et al [55] proved the role of soil texture on tolerance to water stress related to the decrease in fresh weight in roots and shoots. Similar results have been reported on other growth parameters, such as the reduction in vegetative growth or the number of leaves in Phaseolus vulgaris [56,57]. Emam et al [58] investigated the impact of water stress on the growth and development of two common bean cultivars and concluded that all growth parameters were significantly reduced with moisture deficit.…”

Resilience of soybean cultivars to drought stress during flowering and early-seed setting stages

“…However, more research is required in this area. Previous study in soybean also reported a decline in flower load, and seed-set percentage when exposed to drought stress during the gametogenesis-bloom period 55,56 . Apparently, the injury to flowers or pollen caused by drought directly affected seed number, particularly in cultivars that are sensitive to drought stress.…”