低温胁迫对WL系列紫花苜蓿品种抗氧化生理的影响

Antioxidant characteristics and cold resistance evaluation of WL series alfalfa varieties under low temperature stress

摘要:

【目的】 研究紫花苜蓿在低温胁迫下抗氧化生理特性的变化规律，评价不同秋眠级品种的抗寒性。【方法】 选取美国WL系列12个紫花苜蓿品种作为供试材料，于科尔沁沙地种植，越冬前挖取苜蓿越冬材料，模拟4 ℃（CK）和-20 ℃低温胁迫处理，测定根颈丙二醛（MDA）含量和超氧化物歧化酶 （SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）活性，结合相关性分析、主成分分析和隶属函数分析评价抗寒能力。【结果】 与对照相比，低温胁迫下供试的12个苜蓿品种的SOD、CAT和POD的活性和 MDA含量均增加；与其他品种苜蓿相比，WL168HQ、WL298HQ和WL354HQ的抗氧化酶活性较高， MDA的含量较低。对抗氧化酶活性和丙二醛含量进行相关性分析发现，在低温胁迫下，CAT和SOD 与MDA呈显著负相关（P＜0.05）。【结论】 运用隶属函数评价12个品种的抗寒性为：WL168HQ＞ WL329HQ ＞ WL298HQ ＞ WL319HQ ＞ WL349HQ ＞ WL358HQ ＞ WL366HQ ＞ WL377HQ ＞ WL363HQ ＞ WL354HQ ＞ WL343HQ ＞ WL440HQ。建议在科尔沁沙地种植WL系列苜蓿品种选择WL168HQ、WL298HQ、WL319HQ和WL329HQ秋眠级数低、抗寒性强的苜蓿品种。

Abstract:

【Objective】 To investigate the physiological responses of alfalfa to low-temperature stress and to identifyvarieties with high cold resistance.【Method】 Twelve alfalfa varieties of the 'WL' series from the United States were selected as test materials and planted in the Horqin sandy land. Alfalfa overwintering materials were dug prior to overwintering in order to simulate 4 ℃ （ CK ） and -20 ℃ low temperature stress treatment. Malondialde hyde （MDA） content and the activities of superoxide dismutase （SOD），catalase （CAT），and peroxidase （POD） in the root neck were measured. Cold resistance was evaluated using correlation analysis，principal component analysis， and membership function analysis.【Result】 The results showed that compared with the control，the activities of SOD，CAT and POD and the content of MDA in all 12 alfalfa varieties increased under low temperature stress. Com pared with other varieties of alfalfa，WL168HQ，WL298HQ and WL354HQ showed relatively higher antioxidant en zyme activity and lower MDA content. Correlation analysis of antioxidant enzyme activities and malondialdehyde con tent revealed that CAT and SOD had significant negative correlations with MDA under low-temperature stress （P＜0.05）.【Conclusion】Based on membership function analysis，the cold resistance of the 12 varieties was： WL168HQ＞ WL329HQ＞ WL298HQ＞ WL319HQ＞ WL349HQ＞ WL358HQ＞ WL366HQ＞WL377HQ＞ WL363HQ＞WL354HQ＞WL343HQ＞WL440HQ. It is recommended to choose WL168HQ，WL298HQ， WL319HQ，and WL329HQ alfalfa varieties for planting WL series alfalfa varieties in Horqin sandy land，due to their low fall dormancy level and high cold resistance