黔中地区火灾对马尾松外生菌根真菌群落的影响

林火会对森林植被及其相关联的微生物群落产生重要影响。为揭示火灾对马尾松外生菌根真菌(ectomycorrhizal fungi,EMF)群落的影响,本研究以火灾马尾松林为研究对象,以周边立地条件相对一致、未火灾马尾松林为对照,采用形态鉴定与分子生物学技术相结合的研究方法,分析火灾对马尾松EMF群落的影响。共鉴定出马尾松EMF OTUs 69个,隶属于2门7纲15目18科23属,且担子菌门丰富度明显高于子囊菌门。火灾显著改变了马尾松EMF群落的组成和结构,其中火灾马尾松林中EMF群落的优势属主要为蜡蘑属Laccaria、红菇属Russula和棉革菌属Tomentella,未火灾马尾松林中EMF群落的优势属主要为乳菇属Lactarius、棉革菌属Tomentella和土生空团菌属Cenococcum。火灾样地马尾松的EMF群落相对于对照样地在组成与结构上存在明显差异,表现出特有OTUs高于共有OTUs。相对于未火灾马尾松林,火灾马尾松EMF群落的多样性指数和丰富度指数呈下降趋势(P>0.05)。RDA分析表明,pH和TP是影响马尾松EMF群落的重要环境因子。综上所述,火灾干扰是影响黔中地区马尾松EMF群落的重要生态因素之一。

Effects of fire on the community of ectomycorrhizal fungi of Pinus massoniana in central Guizhou,Southwest China

Forest fires can make a notable impact on forest vegetation and associated microbial communities. In this study, the ectomycorrhizal fungi (EMF) community between post-fire forest of Pinus massoniana and non-fire P. massoniana forest with relatively consistent surrounding conditions was compared, and the influence of fire on EMF community was analyzed by combining morphological identification and molecular biology technology. A total of 69 OTUs of EMF was identified, belonging to 2 phyla, 7 classes, 15 orders, 18 families, and 23 genera. The abundance of Basidiomycota was significantly higher than that of Ascomycota. Fire significantly changed the composition and structure of the EMF community of P. massoniana. The dominant genera of EMF community in the post-fire P. massoniana forest were Laccaria, Russula and Tomentolla, while those in the non-fire P. massoniana forest were Lactarius, Tomentolla and Cenococcum. The EMF community of P. massoniana in post-fire plots has obvious differences in composition and structure as compared with that in the control plot, showing that the specific OTUs is higher than the common OTUs. Compared with non-fire P. massoniana forest, post-fire P. massoniana forest showed a downward trend (P>0.05) in diversity index and abundance index of EMF community. RDA analysis shows that pH and TP are important environmental factors affecting EMF community of P. massoniana. To sum up, fire disturbance is one of the important ecological factors affecting the EMF community of P. massoniana in central Guizhou.