松乳菇是一种名贵菌根型食用菌，主要与松科植物形成菌根关系，是全球首个通过菌根技术实现规模化人工培育的伞菌。云南是我国松乳菇的主要产地之一，云南森林土壤多为富含铝铁的红壤，植物可吸收磷含量较低，低磷限制林木生长进而影响松乳菇的产量。植物根系分泌物（如有机酸、酸性磷酸酶等含碳分子）对增加土壤可利用磷含量起着重要作用，根际分泌物也影响着根际微生物群落形成。松乳菇菌根在低磷条件下的分泌物及其对宿主植物磷吸收和根际微生物群落塑造等相关研究十分缺乏。本项目以松乳菇外生菌根为研究对象，分析不同菌株与松树组合在低磷条件下根系和菌根分泌物动态变化；探究其对根际微生物群落和宿主植物磷吸收和生长的影响；初步探讨低磷诱导的外生菌根碳分泌分配的分子和代谢基础。从而揭示松乳菇菌根适应低磷环境的生理机制，为后期松乳菇-松树共生组合筛选及在磷贫瘠地区建立种植园提供科学依据。

Lactarius deliciosus is a valuable edible mycorrhizal mushroom, and mainly have symbiosis relationship with Pinaceae. It is the first agarics cultivated in large scale using mycorrhizal techniques around the world. Yunnan Province is one of the main producting area of L.deliciosus in China, while a large proportion of Yunnan’s forest soil is red soil, which contains high content of Fe and Al but low concentration of plant available phosphorus (orthophosphate, Po). Low Po will limit plants growth and thus their eco-function and mushroom-yield. Root exudates (including low molecular weight carboxylates, amino acids, phosphatases etc) can mobilize both organic and inorganic phosphorus, hence increase the concentration of rhizosphere plant available phosphorus. Moreover, root exudates play an important role in assembling rhizosphere microbial community. However, the exudates of L.deliciosus ectomycorrhizas and their physiological roles in response to low phosphorus availability remain unclear. This project aims to analyze ectomycorrhizosphere exudates of L.deliciosus associated pine and study the physiological roles of these exudates. Meanwhile, molecular mechanisms underlying root exudates and carbon allocation of L.deliciosus ectomycorrhiza under low phosphorus availability will also be explored in this study. The obtained information may serve as reference for guiding selection of pine – L.deliciosus associate combination, and establishing L.deliciosus plantation in phosphorus barren area.