丛枝菌根根外菌丝对不同形态氮素的吸收能力

本试验以玉米为宿主植物,以Glomus mosseae和Glomus intraradices为接种剂,采用空气隔板分室-半液培系统,在植株收获前48 h向菌丝室供应15N标记的不同形态氮素,探讨丛枝菌根根外菌丝吸收传递不同形态氮素的能力。结果表明,丛枝菌根根外菌丝吸收传递15N能力因菌种和氮素形态而异。丛枝菌根真菌G.intraradices吸收传递15N的能力高于G.mosseae,根外菌丝吸收传递不同形态15N的能力为15NH4+>15N-Gln>15N-Gly>15NO3-。根外菌丝吸收传递的15N对植株氮营养的贡献仅为0.004%~0.032%。

UPTAKE OF DIFFERENT FORMS OF NITROGEN BY HYPHAE OF ARBUSCULAR MYCORRHIZAL FUNGI

A two-compartment incorporating air-gap device and()~(15)N_labeling technique was used to investigate the uptake of different forms of N by arbuscular mycorrhizal fungi(AMF).Maize(Zea mays L.) was in association with Glomus mosseae,or Glomus intraradices.Solutions labeled with different forms of()~(15)N were supplied to the hyphae compartment 48 h before harvesting.The result showed that the uptake capability of()~(15)N varied with fungi species and N forms supplied.Percentage of()~(15)N taken up over 48 h by G.intraradices was higher than that by G.mosseae.The uptake capability of()~(15)N by AMF was in the order of()~(15)NH~+_4>()~(15)N-Gln>()~(15)N-Gly>()~(15)NO~-_3.()~(15)N uptake by AMF hyphae accounted for 0.004%～0.032% of total N uptake.