FUNGISTATIC EFFECT OF SOILS ON NEMATOPHAGOUS FUNGI AND THEIR PREPARATIONS
土壤抑菌作用对食线虫真菌及其制剂的影响*

Soil inhibits germination of many fungal propagules- Sensitivity to soilfungistasis may increase the long-term survival of fungal propagules in soil. However,fungi for the use of biological control, especially root-colonizers used as seed-treatment,need to overcome the soil fungistasis in order to colonize and multiple on the plantroots. Paecilomyces lilacinus and Verticillium Chlamydosporium are are multiple on the plantagents for soybean cyst-nematode. In this study, fungistatic effects of 11 soil samplesfrom soybean fields in the northeast and Huanghuai hiver region of China on 4 iso-lates and their preparations (P. lilacinus: M - 14, V chlamydosporium: JN-11, SH -26,BQL-1) associated with Heterodera glycines were tested. The results showed thegermination of pure spores of those fungi was greatly inhibited by the soils fromSuxian in Anhul, Jinan Academy of Agricultural Scienees in Shandong, Bejing andBaoquanling farm in Heilongiiang, and the germination rates of the fungal sporeswere normally below 30%, while the soils from Jingiia in Shandong, Kaifeng inHenan and No'853 farm in Heilongiiang were less infective, and the germinati0n ratesof the spores were ranged from 40% to 80%. There were some different sensitivitiesof the isolates to same soil. The germination rate of spores in filtrate of liquld cul-ture was increased to over 50%, while the germination of the spores in preparationswhich combined with complex additives was greatly enhanced, and the rate was over80%. Soil fungistasis was influenced by the soil microflora. Generally, fungistatic ef-fect was stronger when the microflora was richer. Mechanism research indicated thatfungistatic activity was mainly contributed by water soluble compounds.