以野生和栽培甜瓜为试材,通过人工接种白粉病菌,对两份材料的抗性进行了鉴定,结果表明野生种质对甜瓜白粉病菌生理小种Race1具有抗性。基因测序发现野生种质与栽培品种的MLO基因序列相差85个碱基。进一步利用荧光标记的农杆菌介导法将Cm MLO2基因在野生种质中表达,白粉病菌能够感染阳性转化植株,说明Cm MLO2突变使野生种质缺失MLO蛋白,导致对白粉病的负调控作用被解除,从而启动了对白粉病菌的广谱抗性。
The resistance of cultivar and wild species had been identified used the method of leaves inoculate with Podosphaera xanthii. The results showed that the wild germplasms were resistance to Podosphaera xanthii Race1. There were 85 bp differences between wild and cultivated species after cloning and sequence analysis of their MLO gene. Then CmMLO2 was expressed in wild germplasm using fluorescence-labeled Agrobacterium-mediated method. A positive transgenic plant was successful invasion by Podosphaera xanthii Race1. These results suggested that wild species maybe failing encoded MLO protein,resulting the function of MLO negative regulation to Podosphaera xanthii was losing,which caused wild species had a broad-spectrum resistance to Podosphaera xanthii.