水分胁迫下AM真菌和根瘤菌对沙打旺生长及养分吸收的影响

利用温室盆栽试验研究水分胁迫下接种丛枝菌根（Arbuscular mycorrhizal，AM）真菌和根瘤菌（Rhizobium meliloti）对沙打旺(Astragalus adsurgens Pall.) 生长和养分吸收的影响。在土壤相对含水量65%和35%条件下，分别设不接种（对照）、单接根瘤菌、单接摩西球囊霉(Glomus mosseae)和双接根瘤菌与摩西球囊霉等4个处理。结果发现：干旱胁迫显著抑制沙打旺AM真菌侵染率（P<0.05），而接种根瘤菌在两种水分条件下均显著促进摩西球囊霉对沙打旺根系的侵染（P<0.05）。接种AM真菌不仅显著提高沙打旺对P的吸收（P<0.05），而且明显促进根瘤的生长。无论是在干旱条件下或是在正常供水条件下，双接根瘤菌与摩西球囊霉处理对沙打旺生长及养分吸收的效应显著高于单接菌处理，植株地上部、地下部生物量以及N、P、K等吸收量均为最大。结果表明：AM真菌与根瘤菌双接种技术在干旱、半干旱区受损生态系统的植被恢复中具有一定的应用潜力。

Inoculation of arbuscular mycorrhizal fungi and Rhizobium on the growth and nutrition uptake of Astragalus adsurgens Pall. under water stress

A pot trial was conducted in greenhouse to investigate the effects of arbuscular mycorrhizal (AM, Glomus mosseae) and Rhizobium on the growth and nutrition uptake of Astragalus adsurgens Pall. under water stress. There were four treatments, including control (no inoculation), inoculation of Rhizobium, inoculation of G. mosseae and dual inoculation of Rhizobium and G. mosseae, either in 35% or 65% of soil relative water content. The results showed that water stress significantly (P<0.05) decreased the mycorrhizal infection of A. adsurgens, while the inoculation of Rhizobium significantly (P<0.05) increased the infection regardless of water condition. The inoculation of G. mosseae not only significantly increased P uptake of A. adsurgens, but also increased the growth of root nodules. Regardless of water condition, the dual inoculation of G. mosseae and Rhizobium was superior to the single inoculation with either G. mosseae or Rhizobium. Both the largest biomass of shoot and root and the highest uptake of N, P and K were recorded in the dual inoculation treatment. Therefore, the dual inoculation of G. mosseae and Rhizobium might be a promising approach for revegetation of damaged ecosystem in arid and semi-arid regions.