丛枝菌根真菌改善镉胁迫下植物根系和土壤微环境的效应

为探究Cd胁迫下丛枝菌根真菌(AMF)对植物根系和土壤微环境的影响,以黑麦草为供试植物、变形球囊霉(Glomus versiforme)为供试AMF,以Cd浓度(0、10、20、30 mg·kg^-1)和是否对黑麦草接种AMF为双因素,设计8个处理,开展盆栽试验。结果显示:随着Cd浓度增加,AMF侵染率和孢子数量显著(P<0.05)降低。相同Cd浓度下,接种AMF显著(P<0.05)改善了黑麦草的根系构型(根系总长度、根系总投影面积、根系总体积、根尖数、根分叉数)。在相同Cd浓度下,接种AMF显著(P<0.05)增加了土壤中真菌、细菌和放线菌的数量,土壤微生物生物量碳、微生物生物量氮含量,以及土壤多酚氧化酶活性,和土壤易提取球囊霉素相关土壤蛋白和总球囊霉素相关土壤蛋白含量。这说明,接种AMF能够通过改善植物根系和微生物环境、提高土壤相关酶活性和球囊霉素含量等,增加植物抗性。

Effects of arbuscular mycorrhizal fungi on plant roots and soil microenvironment under cadmium stress

In order to explore the effects of arbuscular mycorrhizal fungi (AMF) on plant roots and soil microorganism,a pot experiment was carried out with Lolium perenne as test plant, and Glomus versiforme as test AMP. Two factors were set: whether Lolium perenne was inoculated with AMF, and Cd concentration (0, 10, 20, 30 mg·kg^-1). It was shown that AMF infection rate and spore number were significantly (P<0.05) decreased with the increasing Cd concentration.Under the same Cd concentration, inoculation of AMF significantly (P<0.05) improved the root architecture (total root length, total root projection area, total root volume, number of root tips and number of root bifurcations) of Lolium perenne.Under the same Cd concentration, inoculation of AMF significantly (P<0.05) increased the number of fungi, bacteria, actinomycetes in soil,contents of soil microbial biomass carbon, soil microbial biomass nitrogen,soil polyphenol oxidase activity, and the contents of easily extractable glomalin-related soil protein and total glomalin-related soil protein. Therefore, it was concluded that AMF could increase plant resistance by improving plant roots and microbial environment, and increasing soil related enzyme activities and glomus content.