白粉病胁迫对甜瓜同工酶谱的影响

[目的]研究甜瓜幼苗叶片中的SOD、POD、CAT同工酶与甜瓜白粉病之间的关系.[方法]以白粉病感病甜瓜品种伽师和白粉病抗病甜瓜品种MR -1为材料,利用PAGE电泳方法分析三种同工酶在接种白粉病前后酶谱的变化.[结果]感病品种伽师和抗病品种MR -1的POD、CAT、SOD受白粉病胁迫后,同工酶谱均有变化,POD酶带在第3d时有新的酶带出现,伽师:P4 (Rf=0.80),MR -1∶P1(Rf=0.68),且感病品种伽师比抗病品种MR-1的POD活性变化更迅速；CAT同工酶无新的酶带出现,但两品种的两条CAT同工酶酶带分别在接种白粉病后3和12d出现两次峰值；SOD同工酶酶活性变化相对较弱,无新的酶带出现,但SOD同工酶酶带S1(Rf=0.50)的活性有变化呈6d增强9d降低的趋势.同时,在接种白粉病后甜瓜白粉病抗病品种MR -1的POD、CAT、SOD酶活性始终比甜瓜白粉病感病品种伽师的酶活性强.[结论]甜瓜幼苗期接种白粉病菌后SOD、CAT、POD的活性变化可以作为衡量甜瓜抗病性的生化指标.

Effects of Powdery Mildew Stress on Isoenzymes of Melon

【Objective】To determine the relationship between isozymes of SOD,POD,CAT of melon seedlings and powdery mildew.【Method】The changes of three kinds of isozymes in susceptible variety of Jiashi melons and MR-1 of resistance variety before and after inoculating powdery mildew were analyzed by using PAGE electrophoresis.【Result】Activity of the 3 kinds of isoenzyes changed and POD emerged a new enzyme after inoculating powdery mildew three days compared with control: jiashi P4(Rf=0.80),MR-1:P1(Rf=0.68),and the changes of the activity of POD isozyme in Jiashi was violent than that in MR-1 during the treatment.The isoenzyes of CAT didn't produce new lane,but two peaks emerged after inoculating powdery mildew 3 days and 12 days.The activity change of SOD was weak compared with others,but the lane of S1(Rf=0.68) had a trend that was higher than that of contrast in day 6 and were lower in day 9.【Conclusion】The defense enzymes SOD,CAT,POD can be used as a measure of indicators of resistance to powdery mildew in melon.