Pearson J N, Abbott L K, Jasper D A
Soil Science and Plant Nutrition, School of Agriculture, The University of Western Australia, Nedlands W A 6009.
New Phytol. 1994 May;127(1):101-106. doi: 10.1111/j.1469-8137.1994.tb04263.x.
We investigated the competition between two arbuscular mycorrhizal fungi, Glomus sp. [isolate WUM 10(1)] and Scutellospora calospora [isolate WUM 12(3)] during the colonization of subterranean clover at four concentrations of soil phosphorus (P). When the clover seedlings were 4 wks old we collected data for plant growth, P uptake, mycorrhizal colonization and soluble carbohydrate status of the roots. The percent and total colonization by Glomus sp. was reduced to a much greater extent than S. calospora when the soil P status was increased. When both fungi were inoculated together, S. calospora was unaffected by the presence of Glomus sp. or the P status of the soil; Glomus sp., however, was reduced to a far greater extent when in the presence of S. calospora than compared to when it was inoculated alone, Associated with the decreases in colonization by Glomus sp., when inoculated alone, with S. calospara and with increases in the level of P applied to the soil, were decreases in the concentration of soluble carbohydrates within the root. We propose that root carbohydrates directly influence the outcome of competition between these two isolates during the colonization of subterranean clover.
我们研究了两种丛枝菌根真菌，即球囊霉属（Glomus sp.）[分离株WUM 10(1)]和褐盾孢囊霉（Scutellospora calospora）[分离株WUM 12(3)]在四种土壤磷（P）浓度下对地下三叶草定殖过程中的竞争情况。当三叶草幼苗长到4周龄时，我们收集了有关植物生长、磷吸收、菌根定殖以及根系可溶性碳水化合物状况的数据。当土壤磷状况提高时，球囊霉属的定殖百分比和总定殖率比褐盾孢囊霉下降的幅度更大。当两种真菌一起接种时，褐盾孢囊霉不受球囊霉属的存在或土壤磷状况的影响；然而，与单独接种相比，球囊霉属在与褐盾孢囊霉共同存在时定殖率下降的幅度要大得多。与球囊霉属单独接种、与褐盾孢囊霉共同接种时定殖率的降低以及土壤施磷水平的提高相关的是，根系中可溶性碳水化合物的浓度降低。我们认为，在地下三叶草定殖过程中，根系碳水化合物直接影响这两种分离株之间竞争的结果。
