Abstract: Using the grafted seedlings of two loquat varieties (Changhong No.3 and Jiefangzhong) as experimental materials, the effects of water stress on physiological determinations in loquat leaves were studied. With the increase of water stress, the content of proline in loquat leaves increased and the content of protein decreased. The activities of H⁺-ATPase in organelles of loquat leaves increased under light or moderate water stress. Under severe water stress, the activities of H⁺-ATPase in cytoplasm decreased greatly, being lower than those of the control, while the activities of H⁺-ATPase in mitochondria and chloroplast were still higher than those of the control. Under the same level of water stress, the decrements of protein in loquat leaves of Changhong No.3 was less than that of Jiefangzhong, while the increments of H⁺-ATPase activities in mitochondria and chloroplast were higher than those in Jiefangzhong. These showed that Changhong No.3 was better than Jiefangzhong in the resistance to drought.

Key words: loquat, water stress, physiological determinations

摘要： 随着水分胁迫程度的加强,枇杷叶片脯氨酸含量增加,可溶性蛋白质含量下降。轻度及中度水分胁迫均使枇杷叶片各细胞器H⁺-ATPase活性增强;严重水分胁迫时,细胞胞质H⁺-ATPase活性急剧下降到对照以下水平,而线粒体及叶绿体的H⁺-ATPase活性仍保持高于对照的水平。同一程度的水分胁迫条件下,长红3号叶片可溶性蛋白质含量降幅小于解放钟,而线粒体和叶绿体H⁺-ATPase活性增幅则大于解放钟,说明长红3号抵御干旱的能力比解放钟强。

关键词: 枇杷, 水分胁迫, 生理指标