有机种植对茶园土壤微生物群落组成与多样性的影响

Influence of Organic Planting on Soil Microbial Community Composition and Diversity in Tea Gardens

为揭示有机种植对土壤微生物群落组成和多样性的影响,以云南省勐腊县3座代表性古茶山(蛮砖、易武、攸乐)的古茶园、现代茶园、橡胶园、荒地4种类型土壤为研究对象,采用Illumina MiSeq PE300高通量测序技术测定其细菌和真菌群落结构,分析有机种植及种植年限对土壤理化性质、微生物群落结构特征与多样性的影响。结果表明,有机种植可促进土壤有机质积累和氮磷钾养分含量提高。3座茶山土壤细菌共有运算分类单元(Operational taxonomic unit,OTU)数目为381个,其中,易武荒地特有OTU最多(293个),蛮砖橡胶园特有OTU最少(28个);而真菌共有OTU数目仅为24个,蛮砖古茶园特有OTU最多(337个),易武现代茶园特有OTU最少(55个)。细菌的Shannon多样性指数达5.88~6.62,明显高于真菌的2.71~4.30。茶园土壤优势细菌和真菌门与非茶园土壤基本相似,但酸微菌目(Acidimicrobiales)、慢生根瘤菌属(Bradyrhizobium)、Varibacter属、黄色杆菌科(Xanthobacteraceae)、硝化螺菌属(Nitrospira)、Bryobacter属、Acidibacter属、浮霉菌科(Planctomycetaceae)等在不同茶山和土地利用方式间的相对丰度差异显著;与荒地和橡胶园相比,茶园土壤真菌群落的毛壳菌科(Chaetomiaceae)、青霉菌属(Penicillium)、镰刀菌属(Fusarium)、木霉属(Trichoderma)、被孢霉属(Mortierella)、伞菌目(Agaricales)和散囊菌纲(Eurotiomycetes)等的相对丰度较高。细菌群落丰度指数Chao1与土壤全氮和全磷呈显著正相关,3座茶山的细菌群落组成较真菌群落更为稳定。除个别茶园土壤外,有机种植下土壤细菌丰度随年限增加而上升,真菌丰度随年限增加先降低后升高,现代茶园和古茶园细菌与真菌的多样性水平则随种植年限增加而下降。

To reveal the influence of organic planting on the community composition and diversity of soil microbial community,4 types of soils(ancient tea gardens,modern tea gardens,rubber fields,wastelands)were used as the research objects in 3 representative ancient tea mountains(Manzhuan,Yiwu and Youle)in Mengla County,Yunnan Province.The community composition of bacteria and fungi were identified using Illumina MiSeq PE300 high-throughput sequencing technology.The effects of organic planting and planting years on soil physical and chemical properties,microbial community composition characteristics and diversity were analyzed.The results show that organic planting could promote soil organic matter accumulation and increase the contents of nitrogen,phosphorus and potassium nutrients.The common number of bacteria OTUs in the soils of three tea gardens and non-tea gardens was 381.Among them,Yiwu Wasteland had highest number of unique OTUs(293),while the Rubber Land of Manzhuan had the lowest number of unique OTUs(28).The total number of fungi OTUs was only 24,with the highest number of fungi OTUs unique to Manzhuan ancient tea garden(337)and the lowest number of OTUs unique to Yiwu Modern Tea Garden(55).In addition,The Shannon diversity index of bacteria reached 5.88-6.62,which was significantly higher than that of fungi(2.71-4.30).The dominant bacteria and fungi in tea garden soils were basically similar to those in non-tea garden soil.However,there were significant differences in relative abundance among identified Acidimicrobiales,Bradyrhizobium,Varibacter,Xanthobacteraceae,Nitrospira,Bryobacter,Acidibacter and Planomyceteaceae among different tea mountains and land use modes.Compared with wasteland and rubber land,the relative abundance of Chaetomiaceae,Penicillium,Fusarium,Trichoderma,Mortierella,Agaricales and Eurotiomycetes in tea garden soil fungal communities were significantly higher than those in other soils.The abundance index of bacterial community Chao1 was significantly and positively correlated with soil TN and TP,and the bacterial community composition was more stable than the fungal community composition of the three mountains with ancient tea plants.Except for some tea garden soils,the abundance of soil bacteria increased with the increase of organic planting and planting years,while the abundance of fungi decreased and then increased with the beginning of organic planting.The diversity level of bacteria and fungi in modern and ancient tea gardens decreased with the increase of organic planting and planting years.