Abstract: Using SDS-PAGE electrophoresis analytic method, a study on the change of drought-induced protein in leaves of alfalfa cultivars under different extents of drought stress was conducted. The result showed that there was a direct correlation between the change of drought-induced protein and drought stress intensity. As drought intensity increased gradually, the drought-induced protein increased initially. and then decreased. The amount of drought-induced protein varied among the different alfalfa cultivars. Those with strong drought-resistance could induce gene to produce more protein to adapt to the drought, while those lacking in drought-resistance would be weakened or lose self-adjustment. Thus, less drought-induced protein was produced. All the strong drought-resistance cultivars, after 15 days under drought stress, were induced to produce a new soluble protein pattern, while only CW300 and Archer Ⅱamong those weak in drought-resistance gave soluble protein pattern. All this indicates that the different cultivars possess distinct genetic diversities. Strong drought-resistance is an important property for breeding new cultivars.

Key words: Medicago sativa, Drought stress, Drought- induced protein

摘要： 利用SDS-PAGE电泳分析法探讨干旱对供试苜蓿品种叶片可溶性蛋白的变化及其与干旱强度的关系。结果表明:可溶性蛋白的变化与干旱强度有直接关系,随着干旱胁迫强度的增加某些可溶性蛋白的变化表现为先增强后减弱;干旱胁迫诱导蛋白量的变化各异,抗旱性强的品种能诱导基因更强的表达以适应干旱胁迫,而抗旱性较弱的品种可能减弱或丧失其自我调节能力,产生的干旱诱导蛋白量比前者少;在干旱15d时,抗旱性强的品种均被诱导产生新的蛋白带,只有两个抗旱性弱的品种出现该谱带;供试苜蓿品种的抗旱性存在明显的遗传多样性,其中抗旱性强的品种是苜蓿抗旱性选育的重要种质资源。

关键词: 紫花苜蓿, 干旱胁迫, 干旱诱导蛋白