Department of Agronomy and Soil Science, University of Hawaii, Honolulu, Hawaii 96822.
Appl Environ Microbiol. 1984 May;47(5):1080-3. doi: 10.1128/aem.47.5.1080-1083.1984.
Experiments were conducted to determine the influence of a toxin-producing fungus on a rhizobial population in yeast-mannitol medium and in a tropical soil. The fungus, which was isolated from a highly weathered soil (Tropeptic Eutrustox), was identified as a Metarhizum sp. The density of rhizobial populations established in yeast-mannitol medium in the absence of the fungus was 10 times higher than that established in its presence. However, the fungus did not exert similar antagonistic influence on the rhizobial population incubated with it in the sterilized test soil. Rhizobial growth activity in yeast-mannitol medium was also insensitive to the presence of the fungus when the medium was amended with 1% (wt/vol) kaolinite or montmorillonite. The results suggest that clay minerals may be responsible for protecting rhizobia against toxin-producing fungi in soil.
实验旨在确定产毒真菌对酵母甘露醇培养基和热带土壤中根瘤菌种群的影响。该真菌是从高度风化的土壤（Tropeptic Eutrustox）中分离出来的，被鉴定为 Metarhizium sp.。在不存在真菌的情况下，酵母甘露醇培养基中根瘤菌种群的密度比存在真菌时高 10 倍。然而，该真菌对在灭菌试验土壤中与其共同孵育的根瘤菌种群没有类似的拮抗影响。当培养基中添加 1%（wt/vol）高岭土或蒙脱石时，真菌的存在对酵母甘露醇培养基中根瘤菌的生长活性也没有影响。这些结果表明，粘土矿物可能负责保护土壤中的根瘤菌免受产毒真菌的侵害。
