不同甜瓜品种蔓枯病抗性与抗坏血酸过氧化物酶 基因 表达的关系

 蔓枯病是威胁甜瓜最重要的病害之一，该病是由西瓜壳二孢菌(Ascochyta citrullina Smith, 无性世代是泄根亚隔孢壳Didymella bryoniae)引起的，在甜瓜的幼苗期至采收期均可发生。在中国厚皮甜瓜栽培品种中尚未发现蔓枯病抗性较好且综合性状优良的品种，多数甜瓜抗蔓枯病材料均为薄皮小果，关于甜瓜与蔓枯病菌的互作机理目前报道较少，厚皮甜瓜和薄皮甜瓜与蔓枯病菌的互作机理差异以及不同品种的薄皮甜瓜间与蔓枯病菌的互作机理差异未见任何报道。在低温高湿环境下甜瓜发生蔓枯病的几率比在适宜生长环境下大大增高，抗坏血酸过氧化物酶(ascrobate peroxidase gene，APX，EC1. 11. 1.11) 是植物耐受逆境胁迫的主要因子，调节活性氧水平，与过氧化氢、一氧化氮一起参与防卫反应和细胞死亡，有可能调节MAPK的级联反应，应对多种环境胁迫因子。本研究拟探讨不同甜瓜品种与蔓枯病菌互作时APX转录水平的变化，初步解释APX在甜瓜与蔓枯病菌互作中的作用。

Relationship between the resistance to gummy stem blight in the different varieties of melon and the transcript profile of ascorbate peroxidase gene

Ascorbate peroxidase gene(APX) plays important roles when plants are in stresses,low temperature and high humidity make it easy that melon are invaded by stem blight disease pathogen Didymella bryoniae.The resistances of melon of 13 varieties to the disease were valued and APX relative expression levels after the inoculation with D.bryoniae strain DB11 were analysed by real time RT-PCR.Eleven varieties with pellicle were resistant to the disease,and 2 thick-skinned ones were high sensitive.It indicated that APX might play roles in the melon resistance to stem blight disease,and the roles in different varieties were not the same.