中文摘要：

以甜瓜感病品种‘白皮脆’、单基因抗源（PI140471、PI157082、PI511890、PI482398、PI420145）和聚合抗源（145-082、082-890、082-398、145-471、145-890和890-398）为材料,采用梯度浓度蔓枯病菌孢子液接种鉴定以及RT-PCR技术,研究不同材料蔓枯病抗性表现以及抗蔓枯病基因（苯丙氨酸解氨酶基因,PAL）在不同材料及不同组织中的表达情况。结果显示：当接种蔓枯病菌孢子液浓度为5×10^9个/mL时,单基因抗源已开始出现感病现象,而聚合基因抗源仍表现为高抗或抗,其中145-471（PI420145×PI140471）抗性显著高于单基因抗源亲本和其它聚合抗源材料,表现为高抗（RI＜1.0）。抗蔓枯病基因PAL在不同抗性材料根、茎、叶中的表达均呈先上调而后下降并趋于稳定的变化趋势,但变化快慢和幅度均不同。研究表明,甜瓜抗蔓枯病基因的聚合能够提高其对蔓枯病的抗性,但不同抗病基因聚合后的抗性表现存在一定差异;抗蔓枯病基因PAL的表达与甜瓜蔓枯病抗性有密切关系,其表达时间与表达量差异可能是影响不同材料抗病能力差异的重要因素;该研究鉴定筛选的高抗蔓枯病材料145-471可用于甜瓜的抗蔓枯病聚合育种。

英文摘要：

With the susceptible variety ‘Baipicui’,single-sources（PI140471,PI157082,PI511890,PI482398,PI420145） and pyramided genes materials（145-082,082-890,082-398,145-471,145-890,890-398） as the tested materials,we investigated the different resistant performance by gradient spores vaccination identification and the different expression of PAL by RT-PCR method.The results showed that when the spores concentration was 5×10^9 mL^-1,the single-sources began to appear susceptible,but the pyramided genes materials still showed high resistance or resistance.The pyramided genes materials 145-471（PI420145×PI140471） showed the highest resistance（RI〈1.0）.Real-time PCR analysis showed that the PAL expression in different tissues were first increased and then reduced to stable,but the change speed and range were different.This study indicated that pyramiding resistance genes could enhance the resistance to GSB,but the resistance performance of different polymeric genes is not the same.The pyramided hybrid 145-471 can be used for pyramiding breeding of melon.The defense gene PAL played an important role in the melon resistance to GSB processes,its higher and earlier expression in the pyramided genes materials can provide higher resistance.