Abstract
Abiotic stresses are the major constraint that limits the productivity of potatoes. Among all the major abiotic stresses, drought is the main stress that is increasing on a yearly basis. Therefore, the current field study was conducted to evaluate the morphological and yield characteristics of 29 potato genotypes. Plants were divided into control and drought stress groups, and plants were acclimatized to drought stress 45 days after sowing (DAS). The irrigation regime was maintained at 3-day interval for control group plants, while for the drought stress treatment, the field was irrigated at 6-day interval. Performance of potato plants was observed by measuring morpho-physiological and yield traits that included canopy temperature, chlorophyll contents, growth duration, plant height, stand establishment, and number of stems per plant. Finally, potato tuber traits were measured (number of tubers, tuber weight, and marketable tuber weight). All potato breeding lines showed contrasting behaviour in response to drought stress. Results showed that potato breeding lines 7, 9, 11, 20, 12, 16, 22, 21, 10, and 18 suggested tolerance as they showed the least reduction in yield characteristics, whereas genotypes 1, 26, 24, 4, 27, 6, 8, 29, 23, 26, 3, and 5 showed poor performance as they failed to cope with stress conditions. Broad sense heritability showed 77% variability that suggested decreased effect of environment on potato genotypes for the selection of high-yielding tubers. The resilient potato breeding lines showed the potential to be stably used as potato breeding material for stress tolerance. These tolerant lines can be used by future breeding programmes to develop resilient cultivars to cope with drought stress problems and to ensure food security.
