1症状大豆胞囊线虫主要为害根部,被害植株发育不良,矮小。苗期:当2~3片真叶形成后,由于根部受害,感病后子叶和真叶变黄,发育迟缓;成株感病地上部矮化和黄萎,结荚少或不结荚,严重者全株枯死。病株根系不发达,侧根显著减少,细根增多,根瘤稀少。发病初期拔起病株观察,可见根上附有许多白色或黄褐色小颗粒,即胞囊线虫雌成虫,这是鉴别胞囊线虫病的重要特 1 Symptoms Soybean cyst nematode is the main root damage, poor plant development, short stature. Seedling: when 2 ~ 3 true leaves formed, due to root damage, cotyledons and true leaves after the disease yellowing, developmental delay; adult plant dwarf and Verticillium wilt, pod less or no pod, Severe whole plant dead. The diseased roots are underdeveloped, the lateral roots are significantly reduced, the fine roots are increased, and the nodules are scarce. Early onset of diseased plants observed, we can see the root with many small white or brown particles, namely female cyst nematode, which is an important identification of cyst nematode disease