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 5×10⁹ 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.