土壤抑菌作用对食线虫真菌及其制剂的影响*

通过我国东北及黄淮海地区主要大豆种植区11种土壤对4株定殖于大豆胞囊线虫真菌淡紫拟青霉（Paecilomyceslilacimus）M-14,厚垣孢子轮枝菌（Verticilliumchlamydosporium）JN-11SH-26和BQL－1孢子的抑制作用及其影响因子的研究，表明土壤抑菌作用普遍存在，但依土壤条件、菌种类型而异，其中以安徽宿县、济南农科院、北京、黑龙江宝泉岭农场的土壤抑菌作用最强，洗涤悬液中孢子萌发率多小于30％，济南敬家、河南开封、黑龙江八五三农场等地土壤抑菌现象不明显，孢子萌发率一般在40～80％。同一土壤对4个菌株的影响是一致的。将菌种液体发酵培养，其滤液孢子萌发率一般可提高至50％以上。加入复合添加剂制得菌剂后，孢子萌发率进一步提高。土壤中微生物数量对其抑菌作用的强弱有很大影响。一般来说土壤中微生物数量越多，抑菌作用表现得也越明显。机理探讨表明土壤中存在着一些水溶性及挥发性的抑制因子，其中水溶性成分是主导因素。

FUNGISTATIC EFFECT OF SOILS ON NEMATOPHAGOUS FUNGI AND THEIR PREPARATIONS

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.