基于宏基因组测序揭示不同施肥方式对茶园土壤微生物群落的季节性影响

Metagenomic analyses reveal the seasonal effects of different fertilization methods on soil microbial community in tea garden

为揭示不同施肥方式对茶园土壤微生物群落的季节性影响,采用宏基因组测序,比较分析了同一茶园习惯施肥(CF)、微生物有机肥配施控释复合肥(MC),在冬季至夏季3个时间点[11月14日(CF1、MC1)、3月1日(CF2、MC2)、5月15日(CF3、MC3)]的土壤微生物群落组成和结构。结果表明,共获得311211956条高质量测序数据和1763759个Unigenes。主成分和相关性分析表明,MC1和CF1的土壤微生物基因丰度聚为一类,其他独聚一类。不同季节,CF和MC的细菌、古菌、真菌分别占微生物总数的88%~89%、0.8%~2.0%、0.02%~0.10%;古菌数量逐渐增加,真菌数量先增加后降低。CF2、CF3的古菌数量分别高于MC2、MC3,而真菌数量相反;CF2、CF3的细菌、真菌丰度分别显著低于MC2、MC3,古菌丰度相反。MC1、MC2、MC3之间的细菌、古菌、真菌丰度存在显著差异,而CF1与CF3的真菌丰度接近。相较于CF,MC提高了土壤细菌中的变形菌门、放线菌门、芽单胞菌门、绿弯菌门、拟杆菌门、硝化螺旋菌门、装甲菌门相对丰度,降低了酸杆菌门、疣微菌门、浮霉菌门相对丰度;提高了古菌中的奇古菌门相对丰度,降低了广古菌门、泉古菌门、深古菌门相对丰度;提高了真菌中的毛霉门、捕虫霉门、隐真菌门相对丰度,降低了担子菌门相对丰度。总体上,CF和MC优势细菌门、优势古菌门、优势真菌门相对丰度的季节性变化趋势存在一定差异。茶园土壤微生物群落组成和结构呈现一定的季节性、施肥方式性变化规律;微生物有机肥配施控释复合肥可以提高土壤细菌丰度、真菌数量和丰度,降低古菌数量和丰度,改变土壤优势菌群的组成,为充分利用微生物资源、提高茶树养分利用率等提供了理论依据。

To reveal the seasonal effects of different fertilization methods on soil microbial community,the soil microbial community structure and composition in a tea garden under conventional fertilization(CF)and bio-organic fertilizer combined with controlled-release compound fertilizer(MC)were analyzed by metagenomic sequencing at three dates from winter to summer[Nov 14(CF1,MC1),Mar 1(CF2,MC2),and May 15(CF3,MC3)].The results showed that 311211956 high-quality reads and 1763759 Unigenes were obtained.The principal component and correlation analysis showed that the soil microbial gene abundances of MC1 and CF1 treatments were clustered into one category,while the other treatments were clustered into one category,respectively.In different seasons,bacteria,archaea and fungi of CF and MC accounted for 88%-89%,0.8%-2.0%and 0.02%-0.10%of total microorganisms,respectively.The number of archaea gradually was increased,while fungal number was first increased and then decreased.The bacterial and fungal abundances of CF2 and CF3 treatments were significantly lower than that of MC2 and MC3 treatments,respectively,with the opposite abundance of archaea.The number of archaea was higher in CF2 and CF3 treatments than in MC2 and MC3 treatments,respectively,while fungal number was reversed.Significant differences in the abundances of bacteria,archaea and fungi were observed among MC1,MC2 and MC3 treatments,but not between CF1 and CF3 treatments.At the phylum level of bacteria,compared with CF treatment,MC treatment had higher relative abundance of Proteobacteria,Actinobacteria,Gemmatimonadetes,Chloroflexi,Bacteroidetes,Nitrospirae and Armatimonadetes,as well as lower relative abundance of Acidobacteria,Verrucomicrobia and Planctomycetes.Among the archaea taxa,MC resulted in higher relative abundance of Thaumarchaeota,as well as lower relative abundance of Euryarchaeota,Crenarchaeota and Candidatus Bathyarchaeota.Among the fungal taxa,MC treatment induced higher relative abundance of Trichoderma,Tracheomycetes and Cryptomycetes,as well as lower relative abundance of Staphylinidae.Generally,the seasonal change trend of the relative abundance of the dominant bacterial phylum,archaebacterial phylum and fungal phylum showed a certain degree of differences in CF and MC treatments.These results indicated that changes in soil microbial community structure and composition in tea garden were probably both season-and fertilization method-dependent.Bio-organic fertilizer combined with controlled-release compound fertilizer increased bacterial abundance and fungal number and abundance,decreased archaea number and abundance,and influenced soil dominant flora composition.These findings provided an important resource for making full use of microbial resources and improving nutrient utilization of tea plants.