4个紫花苜蓿品种对低温胁迫的生理响应及抗寒性评价

本研究选取'肇东'、'龙牧801'、'东农1号'、'敖汉'4种紫花苜蓿(Medicago sativa)作为研究对象,进行低温胁迫试验,通过对生理生化指标和叶片解剖结构的观测分析,综合比较了4种紫花苜蓿的抗寒性.结果表明:低温胁迫下,4种紫花苜蓿相对电导率、丙二醛含量、可溶性糖含量、游离脯氨酸含量、过氧化物酶和超氧化物歧化酶活性与对照相比有所上升,其中'肇东'各个指标的上升幅度均最大.通过隶属函数综合分析得出,4种紫花苜蓿的抗寒性为'肇东'>'龙牧801'>'东农1号'>'敖汉'.通过观测4种苜蓿的解剖结构发现,抗寒性较强的'肇东'和'龙牧801'的叶片厚度、栅栏组织厚度和海绵组织厚度小于抗寒性较弱的'敖汉',且细胞结构更为紧密.

Evaluation of physiological response and cold resistance of four alfalfa cultivars to low temperature stress

Four alfalfa (Medicago sativa) cultivars, ‘Zhaodong’, ‘Longmu 801’, ‘Dongnong No. 1’, and ‘Aohan’, were studied. The cold resistance of the four alfalfa cultivars was comprehensively compared by analyzing physiological biochemical indexes and leaf anatomical structure. The relative electrical conductivity, malondialdehyde content, soluble sugar content, free proline content, peroxidase, and superoxide dismutase activity of the alfalfa cultivars increased compared with the control. Among them, ‘Zhaodong’ had the highest increase in each indicator. Through a comprehensive analysis of the membership function, it was concluded that the cold resistance of the alfalfa cultivars from high to low is as follows: ‘Zhaodong’ > ‘Longmu 801’ > ‘Dongnong No. 1’ > ‘Aohan’. By observing the anatomical structure of the alfalfa cultivars, it was found that the blade thickness, palisade tissue thickness, and sponge tissue thickness of ‘Zhaodong’ and ‘Longmu 801’ with strong cold resistance were less than that of ‘Aohan’, which was less cold resistant, and the cell structure was tighter than that of ‘Aohan’.