高加索三叶草对不同降温模式的抗寒生理响应

Physiological response of Caucasian clover to different cooling modes

为探究高加索三叶草(Trifolium ambiguum)对不同降温模式的生理响应,本研究通过非冷驯化降温(Non‐cold Acclimation,NA)和冷驯化降温(Cold‐Acclimation,CA)对高加索三叶草进行-6℃胁迫处理,观察叶片抗冻形态表现并测定6项生理指标,利用主成分分析筛选评价高加索三叶草在不同降温模式下的抗寒性的生理指标。结果表明:NA组和CA组的叶片在-6℃处理2 h后均能保持正常形态,且绝大部分叶片在24 h内能恢复正常;恢复7 d后,所有参试植株均重新长出新的叶片;随着冷冻胁迫时间的延长,CA组的丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、可溶性蛋白含量和可溶性糖含量均显著高于NA组;过氧化物酶(POD)活性、MDA含量和可溶性糖含量可作为NA组的抗寒指标,可溶性蛋白含量、SOD活性和叶绿素含量可作为CA组的抗寒指标。综上所述,高加索三叶草对于不同降温模式能启动相应的耐寒生理响应,具有较强的抗寒能力,具备在高寒草地引种栽培的潜力。

In order to explore the physiological response of Caucasian clover to different cooling modes,non‐cold acclimation(NA)and cold acclimation(CA)were applied to Caucasian clover at-6℃.The leaf morphology was observed,and six physiological indexes were measured.Principal component analysis was used to screen the physiological indexes suitable for evaluating the cold resistance of Caucasian clover under different cooling modes.The results showed that the leaves of NA group and CA group maintained normal morphology after being exposed to-6℃for 2 h.Most of the leaves returned to normal morphology within 24 hours.After 7 days of recovery,all the tested plants started to grow new leaves again.With the increase in the time duration of cold stress,the MDA content,SOD activity,soluble protein content and soluble sugar content were significantly higher in CA group than those in NA group.The POD activity,MDA content and soluble sugar content could be used as cold‐resistance indexes of NA group,while soluble protein content,SOD activity and chlorophyll content could be used as cold‐resistance indexes of CA Group.In summary,Caucasian clover could deploy different physiological response to different cooling mode,and demonstrated strong ability of cold resistance.It has the potential to be introduced and cultivated in alpine grassland.