Abstract: Reseeding Medicago falcata in Hulunbuir meadow grassland can effectively improve grassland productivity and forage quality,and promote the restoration of degraded grassland. In order to solve the problems of weak growth of yellow alfalfa seedlings and low success rate of establishment,this experiment adopted indoor pot experiment. The no-sterilized soil of degraded grassland in Hulunbuir was used as the matrix soil,and the commonly used species of degraded grassland,yellow alfalfa,was used as the research object to explore the effects of arbuscular mycorrhizal fungi (AMF) on the growth of Medicago falcata seedlings. The results showed that the growth of alfalfa seedlings was regulated by the type and combination of AMF inoculation. After the single inoculation of Funneliformis mosseae,the aboveground and underground biomass of alfalfa decreased,while the simultaneous inoculation of F. mosseae and C. etunicatum significantly increased the underground biomass and total biomass of alfalfa,counteracting the negative effect of the single inoculation of F. mosseae. The joint inoculation of F. mosseae and C. etunicatum activated soil available phosphorus,increased soil nitrogen content,and promoted the absorption of Fe,K,Mg,Mn and P by the roots of alfalfa,thus promoting the growth of alfalfa. Therefore,simultaneous inoculation of F. mosseae and C. etunicatum might promote the growth of alfalfa seedlings and improve the success rate of alfalfa reseeding in Hulunbuir degraded meadow grassland.

Key words: Arbuscular mycorrhizal fungi, Co-inoculation, Degraded soil, Reseeding, Medicago falcata

摘要： 将本土草种黄花苜蓿(Medicago falcata)补播呼伦贝尔草甸草原中，能够提高草地生产力和牧草品质，促进退化草地恢复。为解决原位补播黄花苜蓿幼苗生长弱、建植成功率低的问题，本试验以未灭菌的呼伦贝尔退化草地土壤为基质土，当地常用补播物种-黄花苜蓿为研究对象，探究丛枝菌根真菌(AMF)种类及组合对黄花苜蓿幼苗生长的影响。结果表明，黄花苜蓿幼苗的生长受到AMF种类和组合的调控。同时接种摩西斗管囊霉(Funneliformis mosseae)和幼套近明球囊霉(Claroideoglomus etunicatum)显著提高了黄花苜蓿的地下生物量和总生物量，抵消F. mosseae单接种的负效应。共同接种F. mosseae和C. etunicatum活化了土壤速效磷，提高了土壤氮含量，促进了黄花苜蓿根系对铁、钾、镁、锰、磷的吸收，因而促进了黄花苜蓿的生长。因此，在呼伦贝尔退化草甸草原进行黄花苜蓿补播时，同时接种F. mosseae和C. etunicatum可能促进黄花苜蓿幼苗生长，提高建植成功率。

关键词: 丛枝菌根真菌, 共同接种, 退化土壤, 补播, 黄花苜蓿