Drought Tolerance Evaluation and Verification of Fifty Pakchoi (Brassica rapa ssp. chinensis) Varieties under Water Deficit Condition

Reduced available water resources have become the main limiting factor for production of leafy vegetable, such as pakchoi, which can be effectively addressed by growing water-efficient varieties. Therefore, it is particularly important evaluation and verification drought tolerant In this study, 50 different varieties pakchoi were detected their morphological physiological indicators under both normal-irrigated water-deficiency environments. Based on systematic analysis these using methods, significant identified prediction model was established followed validation The results showed that considerable differences observed in all conditions deprivation compared with normal irrigation. Frequency distribution revealed indictors sensitivity changes to water-deficient ordered follows: aboveground fresh dry weight, belowground root volume, length, activity, soluble sugar. Correlation each indicator significantly or extremely associated other indices, indicating there a certain degree association between indices. Principal component (PCA) turned 16 into four independent components, cumulative contribution ratio 80.147%. According tolerance comprehensive value (D-value) cluster analysis, ranked relation classified five categories, among them Jinhui, Qingguan, Dongyue, Xiazhijiao, Hanszifei, highly drought-tolerant cultivars. Moreover, stepwise regression demonstrated sugar, average diameter, leaf number selected key used screening identifying drought-pakchoi Furthermore, capacity further validated one representative variety from groups treated water-deficit stress. It verified consistent varieties, closely related increasing epidermal stomatal density, maintaining high photosynthesis, antioxidant enzyme activity reduce damage (ROS). proposed provide basis leaf-vegetable drought-tolerances, well could effective water-saving production.