外来入侵物种的入侵机制是入侵生物学的核心科学问题。已有假说主要从天敌、资源和生态位几方面阐述了入侵种的入侵性。但是现有的入侵理论只能解释部分入侵物种的入侵性，所以新的入侵理论令人期待。
2006年至今，中科院动物研究所孙江华研究组以红脂大小蠹－伴生菌为研究模型，以多物种协同作用为切入点，开展了红脂大小蠹入侵机制的研究，继2007年提出外来种与本地种种间协同入侵后，最近又提出了红脂大小蠹伴生菌L. procerum的共生入侵机制。
一方面，中国红脂大小蠹伴生菌L. procerum通过降低寄主油松抗性和诱导寄主油松产生红脂大小蠹聚集化合物（3-carene）来协助红脂大小蠹在入侵地中国的侵入；另一方面，中国红脂大小蠹通过携带其伴生菌L. procerum和诱导寄主油松产生抑制其它伴生菌生长的化合物来协助中国红脂大小蠹伴生菌L. procerum在入侵地中国的侵入。由此从虫－菌种间协同、虫－寄主相互作用、菌－寄主相互作用和菌－菌种间竞争4个方面验证了红脂大小蠹与其中国伴生菌L. procerum的共生关系在入侵地的发展和保持，从而说明红脂大小蠹及其中国伴生菌L. procerum的入侵性。最终提出新的入侵模式——共生入侵。部分数据在线发表在植物学期刊New Phytologist上。
该研究得到国家基金委杰出青年科学基金（30525009）和中科院相关资助。（生物谷Bioon.com）
生物谷推荐原文出处：
New Phytologist DOI：10.1111/j.1469-8137.2010.03316.x
Complex interactions among host pines and fungi vectored by an invasive bark beetle
Min Lu 1 , Michael J. Wingfield 2 , Nancy E. Gillette 3 , Sylvia R. Mori 3 and Jiang-Hua Sun 1
1 State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China ; 2 Tree Protection Co-operation Programme, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa ; 3 PSW Research Station, USDA Forest Service, Berkeley, CA 94701, USA
ABSTRACT
Recent studies have investigated the relationships between pairs or groups of exotic species to illustrate invasive mechanisms, but most have focused on interactions at a single trophic level.
Here, we conducted pathogenicity tests, analyses of host volatiles and fungal growth tests to elucidate an intricate network of interactions between the host tree, the invasive red turpentine beetle and its fungal associates.
Seedlings inoculated with two strains of Leptographium procerum isolated from Dendroctonus valens in China had significantly longer lesions and higher mortality rates than seedlings inoculated with other fungal isolates. These two strains of L. procerum were significantly more tolerant of 3-carene than all other fungi isolated there, and the infection of Chinese pine (Pinus tabuliformis) seedlings by these two strains enhanced the production and release of 3-carene, the main attractant for D. valens, by the seedlings.
Our results raise the possibility that interactions among the fungal associates of D. valens and their pine hosts in China may confer advantages to these strains of L. procerum and, by extension, to the beetles themselves. These interactions may therefore enhance invasion by the beetle–fungal complex.
