中文摘要：

以高抗白粉病的野生甜瓜[Cucumis melo L.ssp.agrestis（Naud.）Greb]‘Yuntian 930’和易感病的甜瓜[Cucumis melo L.ssp.melo（Pang.）Greb]‘0544’为试材,研究二者的叶片结构差异及接种白粉病菌后的活性氧代谢、保护酶活性、多胺含量及相关基因表达量的变化。结果表明：抗性材料‘Yuntian930’的叶片刺毛数量、蜡质含量及栅栏组织/海绵组织比值均显著高于易感病材料‘0544’。与易感病材料‘0544’相比,接种白粉病菌后,抗病材料‘Yuntian 930’的H_2O_2、O_2~和MDA含量上升缓慢,且能维持在较低水平;而SOD、POD和CAT等酶活性显著高于前者。此外,接种白粉病菌后,‘Yuntian 930’的多胺含量及多胺合成相关基因表达量均迅速上升,且最高值显著高于易感病材料‘0544’。这些结果表明,‘Yuntian 930’的抗病性与其叶片形态结构和较高的抗氧化能力、较高的多胺合成能力有关。

英文摘要：

The leaf structure, reactive oxygen species generation, antioxidant enzyme activities, polyamine contents, and expression profiles of polyamine synthesis related genes were compared between a resistant melon variety （Yuntian 930） and a susceptible cultivar （0544） after the inoculation with Podosphaera xanthii. The results showed that the bristles number, waxes content, and ratio of palisade/spong were significantly higher in ‘Yuntian 930’ than those in ‘0544’ After inoculation with P xanthii, the contents of H_2O_2、O_2 and MDA in ‘0544’ rose more slowly and kept a lower level in ‘Yuntian 930’ than in ‘0544’ .However, the activitiesofSOD, POD, CAT in ‘Yuntian 930’ were markedly higher. In addition, the polyamine content and the abundance of polyamine synthesis related genes were increased quickly and reach higher levels in ‘Yuntian 930’ than those in ‘0544’ , after the inoculation with P. xanthii. These results indicated that, the higher resistance to powdery mildew in ‘Yuntian 930’ was related to the leaf morphological structure, higher antioxidant capacity, and higher polyamine synthesis capability.