| Five potato varieties (V7, Atlantic, Experiment 2, Dafeng 8, and Jingzhang 3) were grown in water combined with potassium fertilizer treatment through a pot experiment. Specifically, we established two water gradients (maintaining 80%~85% of the soil’s maximum field water capacity, three rounds of drought and rehydration) and two levels of potassium fertilizer (0 and 180 kg·hm-2) to invest relationship between drought adaptability and potassium nutrient characteristic in different potato varieties. The results showed that the drought adaptation ability of various potato varieties was ranked as Experiment 2 >V7>Dafeng 8>Atlantic>Jingzhang 3. The drought adaptation ability of varieties was positively correlated with their potassium nutrient characteristics. The contribution of potassium utilization efficiency, plant potassium absorption, tuber potassium absorption, and potassium absorption efficiency to drought adaptation was 28.44%, 15.08%, 14.01%, and 8.55%, respectively. The correlation between water use efficiency and potassium utilization efficiency, plant potassium absorption and tuber potassium absorption were all significantly positively correlated in potato under both normal water condition and drought treatment (P＜0.05). The water use efficiency showed highest correlation ]with potassium use efficiency, with correlation coefficients of 0.97 and 0.96, respectively, under normal water condition and drought treatment. It is assumed that potato varieties with strong potassium utilization ability can enhance their adaptive ability to drought by improving water use efficiency. The research results indicate that, Experiment 2 is more suitable for the popularization of planting in the northern arid areas. |