摘要： 采用等电聚焦凝胶电泳比较了抗、感白粉病小麦品种的过氧化物酶同工酶酶谱，发现抗、感品种之间的叶片过氧化物酶同工酶pI 6.1酶带（位于过氧化物酶同工酶等电聚焦凝胶电泳酶谱pI 6.1）在拔节期至白粉病发生期表现水平有很大差别。抗病品种中编码pI 6.1酶带的基因终生正常表达，该酶带在小麦全生育期均有较强的活性，染色后着色深，多属一级酶带。而该基因的表达在感病品种拔节之后受到抑制，酶带变得模糊不清甚至消失踪迹，多为三级、零级酶带。感染白粉病之后酶活性才回升，再度表现为一、二级酶带。为了探索造成这一差异的原因，比较了119株抗病品种与感品种杂交F2代和65株抗病品种/感病品种//感病品种的BC1代植株叶片过氧化物酶同工酶IEF酶谱，证明感病品种成株的pI 6.1酶带活性下降是因另一隐性基因所至。

关键词: 小麦, 过氧化物酶同工酶, 生化标记

Abstract: The isoelectric focusing gel electrophoretic approach was used in this study to compare the peroxidase isozyme bands of wheat varieties, which were either resistant or susceptible to powdery mildew.Great difference was found in the pI 6.1 band of peroxidase isozyme in leaves of resistant/susceptible varieties from the jointing stage to the occurrence of powdery mildew.The genes of the pI 6.1 band in the resistant varieties had a life-long normal expression.This band had a strong activity in the whole growing period of wheat and belonged to the first-class band category.When the expression was suppressed after the jointing stage of the susceptible varieties, resulting in ambiguity or even disappearance of the band, the band often belonged to the category of Class 3 or Class 0 bands.The enzyme gained activity after the infection of powdery mildew, resulting in the formation of Class 1 or Class 2 bands.In order to find the factors causing this difference, the peroxidase isozyme IEF bands in leaves were compared between the 119 F2 plants of resistant/susceptible varieties and the 65 BC1 plants of resistant/susceptible varieties.Results show that the decrease in the activity of the pI 6.1 band in susceptible adult plants is caused by another recessive gene.

Key words: Wheat, Peroxidase isozyme, Biochemical marker