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经过9年在塔里木盆地边缘干旱区对伽师县等3个相互隔离的甜瓜霜霉病流行系统的实地调查研究,提出了甜瓜霜霉病远距离传播的三级空间结构。一个甜瓜霜霉病流行系统单元是在一个绿洲内,围绕可提供初侵染病原的黄瓜温室区而形成的,其空间结构分为区系(包含若干种植区)、种植区(包含若干田块)和田块三级结构。伽师甜瓜霜霉病流行区系分为3个种植区,甜瓜霜霉病每年春季最先从位于种植一区发生霜霉病的黄瓜温室附近的甜瓜开始发生,之后甜瓜霜霉病由近向远逐步传播。种植二区和种植三区甜瓜霜霉病的初发病时间(初发病中心出现的时间)比种植一区的分别平均晚20和45d,发病中心与初菌源地的平均距离分别是56.4和106.5km,表明此地甜瓜霜霉病菌远距离传播经历了从种植一区到种植二区,再从种植二区到种植三区的传播过程。
After nine years of field investigation on the epidemic system of three isolated melon downy mildew in Jiashi County in the arid region of Tarim Basin, the tertiary spatial structure of melon downy mildew was proposed. A melon downy mildew epidemic system unit is formed in an oasis around the cucumber greenhouse zone which provides the first infestation of the pathogen. Its spatial structure is divided into fauna (including several growing areas), planting areas (including several fields ) And Tian three-tier structure. Jiashi melon downy mildew epidemic division is divided into three planting areas, melon downy mildew first spring of each year in the planting of a cucumber downy mildew greenhouse cucumber greenhouse melons began to occur, after the melon downy mildew from near to the Far from the spread. The initial onset time (initial onset time) of the first generation of melon downy mildew in the second district and the planting three districts was 20 and 45 days later than that of the first district respectively, and the average distances between the center of incidence and the first origin were 56.4 and 106.5 km, indicating that the long-distance transmission of downy mildew caused by downy mildew has gone through from planting area to planting area two, then from planting area two to planting area three spreading process.