Screening of stages and indexes for cucumber wet-cold tolerance identifi-cation

DING Yuanyuan; PAN Yupeng; LIU Hanqiang; MENG Huanwen; CHENG Zhihui

doi:10.16861/j.cnki.zggc.2024.0737

Abstract：To screen the stages and indexes for cucumber wet-cold tolerance identification,three stage seedlings of 3 culti-vars with different wet-cold tolerance,and seedlings at 2 leaf stage of 8 different wet-cold tolerant cultivars were treated in growth chamber under wet-cold(9℃/5℃+RH 95％)condition taking 28℃/18℃+RH 75％as the control.The growth and physiologic indexes of seedlings were collected and their relative values were analyzed.The results showed that wet-cold treatment significantly inhibited the growth and physiologic metabolism of cucumber seedlings,and induced antioxidant,osmotic regulation and enzyme protection reactions.Under wet-cold stress,the growth and physiologic index-es of seedlings at 2-leaf,3-leaf and 4-leaf stage could better indicate the wet-cold tolerance of the cultivars,but the 2-leaf stage was better for early identification.Based on cluster analysis,correlation analysis and variation analysis,plant height,fresh mass and dry mass of seedlings were first recommended in morphological indexes,followed by stem diameter and length and width of the first true leaf.The content of proline,activity of catalase,stomatal conductance,transpiration rate,activity of peroxidase,content of malonaldehyde and concentration of intercellular carbon dioxide were first suggested in physiologic indexes,followed by content of superoxide anion free radical,electron transport rate,actual quantum efficiency,non-photochemical quenching coefficient.