马尾松根生产苗与常规苗外生菌根真菌多样性特征

以湖南省林业科学院龙伏试验基地3年生常规方法培养的马尾松苗Pinus massoniana（以下简称常规苗）和3年生马尾松根生产（root production method,RPM）苗根、根际土为研究对象,采用 Illumina MiSeq 测序技术研究其根系及根际土壤外生菌根真菌（ectomycorrhizal fungi,ECMF）群落结构特征,旨在探明其土壤微生境的差异,进而为人工接种菌根真菌及改良常规苗的土壤微生境奠定基础。测序共获得170 148条ECMF序列,划分为20个OTUs（operational taxonomic units,OTU）,隶属于2门、3纲、7目、8科、11属。Chao1丰富度指数、Ace丰富度指数、Simpson多样性指数与Shannon-Wiener多样性指数均表现为常规苗根际土的OTUs丰富度高于RPM苗根际土,并且根样OTUs丰富度低于根际土样（P<0.05）。不同样品的ECMF优势属占比也不同,RPM苗根样中占比最大的为Amphinema（47.89%）,常规苗根样为Tomentella（70.60%）;RPM苗土样中占比最大的为Tylospora（62.33%）,常规苗土样为Tomentella（55.69%）。冗余分析表明,土壤pH值对ECMF的影响程度最大,其次为速效磷和有机质;同时,不同理化因子对群落多样性指数及优势属的影响也存在差异。

Ectomycorrhizal fungal community structure characteristics of Pinus massoniana seedlings breeded by root production method and ordinary breeding method

The roots and rhizosphere soil of 3-year-old Pinus massoniana seedlings (hereinafter abbreviated to ordinary seedlings) breeded by conventional methods and 3-year-old pot culture seedlings breeded by root production method (RPM) (hereinafter abbreviated to RPM seedlings) in Longfu Experimental Base of Hunan Academy of Forestry Sciences were selected as experimental materials, and the ectomycorrhizal fungi (ECMF) of the roots and rhizosphere soil were investigated by Illumina MiSeq sequencing technology for the purposes of finding out the difference community structure of ECMF in different soil microenvironment, providing reference data for artificial inoculation of mycorrhizal fungi and improving the soil microenvironment of ordinary seedlings, and ultimately increasing the survival rate and stress resistance ability of the seedlings. A total of 170 148 ECMF sequences was obtained and they were divided into 20 OTUs (operational taxonomic units, OTUs), belonging to 2 phyla, 3 classes, 7 orders, 8 families and 11 genera. Chao1 richness index, ACE richness index, Simpson diversity index and Shannon Wiener diversity index showed that the OTUs richness of ECMF in ordinary seedling rhizosphere soil was higher than that in RPM seedling rhizosphere soil, and the OTUs richness of ECMF in root sample was lower than that in rhizosphere soil (P<0.05). The dominant genera of ECMF in different samples were different. Amphinema (47.89%) in root samples of RPM seedlings accounted for the largest proportion of ECMF; Tomentella were dominant (70.60%) in ordinary seedlings. Tylospora (62.33%) in RPM seedlings was dominant and Tomentella (55.69%) was dominant in rhizosphere soil samples of ordinary seedlings. Redundancy analysis showed that soil pH had the greatest impact on ECMF, while available phosphorus and organic matters less impacted. Different physical and chemical factors had different effects on community diversity index and dominant genera of ECMF.