Effect of moisture stress on different cucurbits: a morpho-physiological and biochemical perspective

Climate change poses a major threat to global crop production and food security, with cucurbit crops particularly vulnerable to heat, drought, and other climatic stresses. In this study, seven Cucurbitaceae species—bottle gourd, sponge gourd, ridge gourd, pumpkin, ash gourd, Summerfit (an interspecific hybrid of snap melon), and cucumber—were evaluated for tolerance to moisture stress. Plants were subjected to two irrigation regimes (50% and 75% of field capacity) after 15 days of transplanting, and morphological, physiological, and biochemical traits were assessed after 65 days. Severe reductions in growth and physiological performance occurred at 50% field capacity, indicating intense water-deficit stress. Bottle gourd exhibited the lowest reduction in relative water content (7.72%), while ash gourd showed the lowest reduction in membrane stability index (22.88%). Hierarchical clustering grouped bottle gourd and ash gourd as highly drought-tolerant species. Principal component analysis confirmed their superior performance, with higher catalase activity, root length, root surface area, root volume, root density, shoot length, and shoot dry weight under moisture stress. These findings suggest that ash gourd and bottle gourd enhance water uptake through improved root architecture, making them promising rootstocks for cucumber cultivation in water-limited environments.