不同生態型摩西球囊黴菌株對蜈蚣草砷吸收的影響

砷超富集植物——蜈蚣草無論是在野外或是在室內均能被叢枝菌根真菌（AM真菌）侵染，但其對蜈蚣草砷吸收及轉運的機理尚不清晰。本研究將分離於湖南省郴州市金川塘某鉛鋅尾礦蜈蚣草根際土壤（Glomus mosseae BGC GD01,簡稱污染菌株）和云南省未污染土壤（G.mosseae BGC YN05，簡稱非污染菌株）的2種摩西球囊霉菌株分別接種於非污染生態型和污染生態型蜈蚣草根際，8周后利用菌根化蜈蚣草幼苗在濃度為100μmol·L^-1砷（Na₂HAsO₄·7H₂O）營養液中進行為期24h的水培試驗。結果表明，2種生態型摩西球囊霉菌株分別與蜈蚣草形成中等程度侵染，侵染率為25.2%～31.3%。無論是接種污染菌株或是非污染菌株，均明顯促進了蜈蚣草根部對磷的吸收。在24h水培試驗期間，接種非污染菌株顯著促進了蜈蚣草根部砷的吸收，但接種污染菌株對蜈蚣草根部砷吸收的促進作用有限，說明AM真菌對蜈蚣草砷吸收存在種內差異。


Pteris vittata, as an arsenic (As) hyperaccumulator, can be colonized by arbuscular mycorrhizal (AM) fungi either in controlled conditions or at field sites. However, the physiological mechanisms of AM fungi affecting the As accumulation and translocation in P. vittata are not fully elucidated. In this study, two isolates of Glomus mosseae were obtained from the rhizosphere of P. vittata growing on an As-contaminated site in Jinchuantang of Hunan Province (G. mosseae BGC GD01A, metal-contaminated isolate) and from the clean soil in Yunnan Province (G. mosseae BGC YN05, uncontaminated isolate). The isolates were inoculated to the rhizosphere of As-contaminated and uncontaminated P. vittata, respectively. After 8 weeks of inoculation, a 24-h water culture experiment was conducted with the P. vittata seedlings colonized by AM fungi and exposed to 100 μmol·L^-1 of As (Na₂HAsO₄·7H₂O). Both the two isolates could colonize on P. vittata roots at moderate level (25.2%-31.3%). The inoculation either with metal-contaminated isolate or with uncontaminated isolate promoted the P uptake by P. vittata roots obviously. During the 24 h culture, the inoculation with uncontaminated isolate promoted the As uptake by P. vittata roots significantly, while the inoculation with metal-contaminated isolate only had a slight effect in promoting the As uptake, showing that there was an intraspecific difference of AM fungi in their effects on the As uptake by P. vittata. Copyright © 2013 中國生態學學會.