干旱胁迫和复水对扁蓿豆幼苗生理特性的影响

摘要

采用温室模拟干旱胁迫-复水法,研究不同干旱程度对6份扁蓿豆种质材料幼苗生理特性的影响,分别于莲续干旱胁迫1,4,7,10 d以及复水2d后,对其叶片相对含水量、细胞膜透性、丙二醛含量、脯氨酸含量、可溶性蛋白含量5个抗旱生理指标进行测定分析,结果表明:扁蓿豆叶片相对含水量随干旱胁迫程度增强而降低,在复水后快速恢复；细胞膜透性、丙二醛含量及可溶性蛋白含量随干旱程度的增加而升高,而脯氨酸含量则呈先下降后上升的趋势;5个生理指标中脯氨酸含量对干旱胁迫最敏感.采用欧氏距离法对5个生理指标进行综合聚类分析,将6份扁蓿豆种质材料划分为3个抗旱等级,即相对抗旱的包括MR4和MR5；中等抗旱的包括MR1、MR2和MR3；对干旱胁迫最敏感的是MR6.%The drought resistance of 6 germplasm materials of Medicago ruthenica was identified and evaluated using simulated drought stress and rehydration in a green house. The relative water content of leaves,cell membrane permeability,maiondialdehyde content, proline content and soluble proiein content were measured at 1 ,4,7,10 d of drought stress and 2 days after rehydration. The relative water content of Medicaga ruthenica leaves decreased with drought stress enhanced,but rapid recovery after rehydration. Cell membrane permeability,malondialdehyde content and soluble protein content increased with drought stress enhanced,but proline content was first decreased and then increased. Proline content was the moat sensitive to drought stress in five physiological indexes. The three drought resistant classes :high drought resistance ( MR4 and MR5 ) .medium drought resistance ( MR 1 , MR2 and MR3 ) and weak drought resistance ( MR6)were classified using the above 5 physiological indexes by the Euclidean distancernclustering method.