Dry Lands Research Institute and Department of Soil and Environmental Sciences, University of California, Riverside, California 92521, and Biology Department and Systems Ecology Research Group, San Diego State University, San Diego, California 92182.
Appl Environ Microbiol. 1987 Jan;53(1):36-40. doi: 10.1128/aem.53.1.36-40.1987.
Soil samples were collected from the surface (0 to 0.6 m) and phreatic (3.9 to 4.5 m) root systems of a Prosopis glandulosa woodland in the Sonoran Desert of southern California. P. glandulosa seedlings were inoculated with these soils, and rhizobia were isolated from nodules. The phreatic soil, characterized by constant moisture and temperature but low nutrient availability, favored slow-growing (SG) isolates as nodule occupants (85%). SG isolates from the surface and phreatic soil were distinct based on differences in colony morphology. Isolates from the surface soil, characterized by high nutrient availability and widely fluctuating water content and temperature, were equally represented by fast-growing and SG rhizobia. Most SG isolates (83%) had nodule relative efficiencies of <0.80, whereas 54% of the fast-growing isolates had relative efficiency values of >0.80.
从加利福尼亚州南部索诺兰沙漠的一株牧豆树林地的表层（0 至 0.6 米）和潜水根系统（3.9 至 4.5 米）中采集了土壤样本。将这些土壤接种到牧豆树幼苗上，并从根瘤中分离出根瘤菌。潜水土壤的特点是水分和温度恒定，但养分供应不足，有利于生长缓慢（SG）的菌株作为根瘤菌占据者（85%）。来自表层和潜水土壤的 SG 分离株在菌落形态上存在差异。表层土壤中的分离株具有高养分供应和广泛波动的含水量和温度，其快速生长和 SG 根瘤菌的比例相等。大多数 SG 分离株（83%）的根瘤相对效率<0.80，而 54%的快速生长分离株的相对效率值>0.80。
