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Soybean cyst nematode larvae directly infect soybean roots, directly related to the population density and the harm caused to plants, so look the nematode larvae hyperparasite is an important way for biological control of soybean cyst nematode. \Separation of the trapping and direct separation of soybean cyst nematode larvae isolated from soil samples parasitic fungi, the Hirsutella (Minnesota Hirsutella 30 were detected in 32 soil samples; of Luo Sili Hirsutella 2) Aureobasidium Acremonium Phoma Paecilomyces section seven each from Alternaria, Trichoderma, Chaetomium Cong Terrier spore, 4 parts, 3 parts, 3, 2, 1 part and soil samples were detected, and Pasteurella found in 38 soil samples. Hirsutella, Minnesota, of Luosi Li Hirsutella and Pasteurella the soil sample detection rates were 20.5%, 1.4% and 26.0%, respectively. Hirsutella mainly located in Heilongjiang Province, soil samples detection rate of 19.2%, Shaanxi, Henan and Liaoning, a small amount of the distribution. Pasteurella mainly distributed in the Huang-Huai-Hai region, Anhui, Henan, Jiangsu and Shandong, soil samples were detected in 10.2%, 6.8%, 3.4% and 2.7%, respectively, Heilongjiang, Jilin, Liaoning and Beijing also has a small amount of the distribution. Hirsutella and Pasteurella the parasitic rate most of the second instar larvae of the soybean cyst nematode is less than 50%, but can be as high as 100% in individual soil samples. The comparison shows that the direct separation and trapping separation Pasteurella separation trapping soil samples detection rate (21.9%) was significantly higher than the direct separation method (11.6%), two separate methods of Hirsutella soil samples detection rate (16.4%) is almost the same. On the the 5.8s rDNA base sequence of a Thomson Hirsutella strains and Luo Sili Hirsutella six strains ITS1-ITS4 area measurement results support the the morphological classification results. From different host nematode Luo Sili Hirsutella kinship than the same host Luo Sili Hirsutella far. Pasteurella and Hirsutella parasitic rate factor analysis results showed that the population density of the soybean cyst nematode parasitism rate was positively correlated, but not significantly. Hirsutella parasitic sandy loam, slightly alkaline, low organic matter content of the soil is high; Pasteurella parasitic rate and soil factors was not significant. The host range of the test showed that the strains of the Hirsutella the two -, Hirsutella 136, Minnesota soybean cyst nematode, Bursaphelenchus xylophilus, saprophytic nematodes, insects, nematodes, etc. In addition to the root-knot nematode and an insect pathogenic nematodes variety The nematodes have parasitic; Luo Sili Hirsutella ATCC46487 tested nematodes parasitic, and 136 the parasitic higher than Minnesota Hirsutella. Pasteurella only attached to the soybean cyst nematode, and the attachment of many spore count, average 6 / nematodes.
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