为探明褐斑病空间分布对夏玉米光合酶和保护酶活性的影响,通过2年人工定量接菌田间小区试验,研究了8叶期、10叶期、吐丝期和灌浆期褐斑病在单株夏玉米上的空间分布规律及其对4个生育期植株不同叶位叶片光合酶和保护酶活性的影响。试验结果表明:褐斑病能使夏玉米叶片保护酶、光合酶的活性明显下降,叶片MDA含量显著增高,且空间分布病级越高,影响越大,玉米早衰也越严重。 In order to investigate the effect of spatial distribution of brown spot on the photosynthetic enzyme and protective enzyme activities of summer maize, two-year artificial quantitative inoculation field experiments were carried out to study the effects of brown leaf spot on the 8-leaf stage, 10-leaf stage, silking stage and filling stage The Spatial Distribution of Summer Maize and Its Effects on the Activity of Photosynthetic Enzymes and Protective Enzymes in Leaves at Different Leaf Positions in Four Growth Stages. The results showed that brown spot could significantly reduce the activity of protective enzymes and photosynthetic enzymes in summer maize leaves, and significantly increase the content of MDA in the leaves. The higher the degree of spatial distribution was, the more serious the premature aging was.