罗田板栗外生菌根真菌多样性研究

Community structure of ectomycorrhizae fungi associated with Castanea mollissima in major producing area of Chinese chestnut (Luotian)

【目的】为了解中国板栗主产区(罗田)的板栗地下外生菌根真菌多样性,对罗田地区80年以上的代表性板栗园的板栗外生菌根真菌群落组成和形态特征进行研究,并在形态分类的基础上对其进行分离鉴定。【方法】共采集到300份板栗根系样品,根据形态、颜色和分叉程度等特征进行分类后获得55个外生菌根类型。每种类型选取3个重复根段制备混合样品,对混合样品进行ITS分析。【结果】前50位的OTU分属于34属、15个未分类种和其他类群。其中丰度前20的类群占95.99%:Basidiomycota约占60%,包含Lactarius、Guehomyces、Inocybe、Russula和unclassified_Thelephoraceae 5个主要属;Ascomycota约占30%;Mortierellomycota约占5%,其余5%则属于未分类的真菌。在分离得到的22种外生菌根真菌中,Trichoderma物种丰富度最高(6种),其次是Fusarium(4种)、Penicillium(3种)、Talaromyces(3种)、Pestalotiopsis(2种),Ilyonectria、Castanediella和Leptodontidium各1种。其中与Fusarium、Trichoderma、Talaromyces和Penicillium等4种真菌同源性较高的11株菌已被报道具有生防功能,分离得到11株菌也可能具有较好的生物防治潜力。【结论】本研究系统揭示了中国板栗主产区的板栗外生菌根真菌群落组成,分离得到具有生物防治功能的菌根真菌,为进一步提高板栗抗性奠定基础。

【Objecctive】The present paper aimed to know the below-ground ectomycorrhizal status of Castanea mollissima in the major producing area(Luotian county) of Chinese chestnut. The EMF community composition, morphological and molecular identification of C. mollissima were investigated in representative ≥80-year-old chestnut orchards in Luotian. 【Method】300 root samples of C. mollissima were collected and a total of 55 ECM morphotypes were obtained based on morphological characters.【Result】The top50 OTUs were assigned to 34 genera, 15 unclassified species and other taxa. The top 20 taxa in abundance accounted for 95.99% of the top50 OTUs, which were belonged to Basidiomycota(account for 60%, contained five dominant genera: Lactarius, Guehomyces, Inocybe, Russula and unclassified_Thelephoraceae), Ascomycota(30%), Mortierellomycota(5%), and other(5%) were belonged to unclassified fungi. Furthermore, among the 22 EMF identified, genus Trichoderma had the largest variety of strains(6), followed by Fusarium(4), Penicillium(3), Talaromyces(3), Pestalotiopsis(2), and other three genera: Ilyonectria, Castanediella, and Leptodontidium each possessed 1 specie. Of these fungi, 11 strains sharing high homology with strains which belonged to Fusarium, Trichoderma, Talaromyces and Penicillium were reported with biocontrol function previously, which indicated the 11 strains isolated might also have the potential of biological control. 【Conclusion】This was the first study to characterize the ECM communities in major producing area of Chinese chestnut, which would lay a foundation for improving chestnut resistance by ectomycorrhizal fungi.