Department of Microbiology, University of Hawaii at Manoa, Honolulu, Hawaii 96822.
Appl Environ Microbiol. 1985 May;49(5):1128-33. doi: 10.1128/aem.49.5.1128-1133.1985.
The effect of several biotic and abiotic factors on the pattern of competition between two strains of Rhizobium japonicum was examined. In two Minnesota soils, Waseca and Waukegan, strain USDA 123 occupied 69% (Waseca) and 24% (Waukegan) of the root nodules on Glycine max L. Merrill cv. Chippewa. USDA 110 occupied 2% of the root nodules in the Waseca soil and 12% of the nodules in the Waukegan soil. Under a variety of other growth conditions-vermiculite, vermiculite amended with Waseca soil, and two Hawaiian soils devoid of naturalized Rhizobium japonicum strains-USDA 110 was more competitive than USDA 123. The addition of nitrate to or the presence of antibiotic-producing actinomycetes in the rhizosphere of soybeans did not affect the pattern of competition between the two strains. However, preexposure of young seedings to USDA 110 or USDA 123 before transplantation into soil altered the pattern of competition between the two strains significantly. In the Waseca soil, preexposure of cv. Chippewa to USDA 110 for 72 h increased the percentage of nodules occupied by USDA 110 from 2 to 55%. Similarly, in the Hawaiian soil Waimea, nodule occupancy by USDA 123 increased from 7 to 33% after a 72-h preexposure.
研究了几种生物和非生物因素对两株根瘤菌竞争模式的影响。在明尼苏达州的两个土壤（Waseca 和 Waukegan）中，菌株 USDA 123 占据了 Glycine max L. Merrill cv. Chippewa 根瘤的 69%（Waseca）和 24%（Waukegan）。 USDA 110 占据了 Waseca 土壤中 2%的根瘤和 Waukegan 土壤中 12%的根瘤。在各种其他生长条件下（蛭石、添加了 Waseca 土壤的蛭石和两个没有天然根瘤菌菌株的夏威夷土壤），USDA 110 比 USDA 123 更具竞争力。在大豆根际添加硝酸盐或存在产生抗生素的放线菌不会影响两株菌之间的竞争模式。然而，在移栽到土壤之前，将幼苗预先暴露于 USDA 110 或 USDA 123 会显著改变两株菌之间的竞争模式。在 Waseca 土壤中，将 cv. Chippewa 预先暴露于 USDA 110 72 小时，使 USDA 110 占据的根瘤百分比从 2%增加到 55%。同样，在夏威夷土壤 Waimea 中，经过 72 小时的预先暴露，USDA 123 占据的根瘤比例从 7%增加到 33%。
