渗透胁迫条件下不同抗旱性小麦品种萌发期生理生化指标的变化

为给小麦苗期抗旱鉴定提供依据。以17个抗旱性不同的小麦品种为材料，在渗透胁迫（-0．975MPa）条件下。研究了小麦萌发后期部分生理生化指标的变化，并在旱棚池栽控水条件下对品种的抗旱性进行了比较鉴定。结果表明，在渗透胁迫条件下，不同小麦品种萌发期胚芽鞘的脯氨酸含量、胚芽鞘和胚根的MDA含量升高，而胚芽鞘和胚根的SOD、CAT活性以及可溶性蛋白质含量下降。其中胚芽鞘脯氨酸含量、CAT活性、SOD活性均与抗旱指数、抗旱系数相关极显著，反映抗旱性强弱趋势基本一致，可作为小麦早期的抗旱性鉴定指标。渗透胁迫条件下胚芽鞘脯氨酸、CAT和SOD的T／CK值（胁迫测定值／对照值）分别大于2．2、0．8和0．8为强抗旱性品种，而抗旱性弱的品种则分别小于1.5、0．65和0．4。

Effect of Osmotic Stress on Physiological and Biochemical Indices at Germination Stage of Different Drought-Resistant Wheat

In this research,the effect of osmotic stress(-0.975 MPa) on the coleoptile and radicle growth was studied with 17 drought resistant wheat genotypes at germination stage,and several physiological and biochemical indices were analyzed.The results showed the variation and ranking of genotypes based on the relative value(T/CK) of proline content,SOD and CAT activity of plumule was rather similar to that based on the yield reduction rate in field water deficit experiment.So the above physiological and biochemical indices could be suggested for drought tolerance identification in wheat. For drought tolerant genotypes,the relative value(T/CK) of proline content,SOD or CAT activity of plumule should be larger than 2.2,0.8 and 0.8,respectively,while for drought sensitive ones,the relative value should be less than 1.5,0.65 and 0.4,respectively.