炭基肥对植烟黄壤细菌、真菌群落结构和多样性的影响

【目的】探究施用炭基肥对植烟黄壤质量影响的微生物学机制,为应用炭基肥培育植烟黄壤肥力提供科学依据。【方法】2016年,以烤烟品种云烟87和贵州黄壤为供试材料,通过大田试验,设置不施肥(NF)、常规肥(CF,条施有机肥和烤烟专用基肥,穴施烤烟专用追肥)和炭基肥(BF,条施炭基有机肥和炭基复混肥,穴施烤烟专用追肥) 3个处理,2年后采集样品,采用Illumina Miseq高通量测序技术,剖析土壤细菌、真菌群落结构和多样性的响应差异,揭示影响微生物的主要土壤因子。【结果】与NF处理和CF处理比较,BF处理烤烟产量提高,土壤碱解氮和有效磷含量显著提高。BF处理土壤细菌OTUs数量最大(1592),显著大于其余两处理;土壤细菌丰富度和多样性指数最高。BF处理土壤真菌OTUs数量最小(280);土壤真菌丰富度和多样性指数最低。BF处理土壤细菌群落物种最多样,属于25个门,CF处理属于23个门,NF处理仅属于22个门。细菌门水平,BF处理拟杆菌门(Bacteroidetes)相对丰度(1.50%)提高,Latescibacteria相对丰度(0.11%)降低;与NF处理比较,拟杆菌门、Latescibacteria相对丰度差异显著。真菌门水平,BF处理接合菌门(Zygomycota)相对丰度(2.18%)显著降低;与NF处理相比,壶菌门(Chytridiomycota)相对丰度(0.01%)显著降低。真菌属水平,BF处理镰刀菌属(Fusarium)相对丰度(5.83%)显著降低;与NF处理相比,BF处理被孢霉属(Mortierella,2.11%)、葡萄穗霉属(Stachybotrys,0.90%)、链格孢属(Alternaria,0.01%)(烟草赤星病病原菌)相对丰度显著降低。不同施肥处理下,引起细菌群落结构变化的最主要土壤因子为pH,导致真菌群落结构变化的最主要土壤因子为有效磷。【结论】炭基肥引发土壤生物化学环境改变,进而导致土壤细菌、真菌群落结构和多样性发生变化,优化土壤生态。

Effect of biochar-based fertilizer on bacterial and fungal community composition, diversity in tobacco-planting yellow soil

Objective] This study was to explore the effect of biochar-based fertilizer application on the microbiological mechanism of the quality of tobacco-planting yellow soil. Methods] In 2016, 3 different treatments were designed:no fertilizer (NF), conventional fertilizer (CF) and biochar-based fertilizer (BF). Illumina miseq sequencing was applied to analyze soil bacterial and fungal communities. Results] Compared with NF and CF treatments, the yield of flue-cured tobacco was increased, the contents of soil alkaline hydrolyzed N and available P were increased significantly in the BF treatment. In the BF treatment, the number of operational taxonomic units (OTUs, 1592), abundance and diversity indexes of soil bacterial community were the highest. However, the number of OTUs (280), abundance and diversity indexes of soil fungal community were the lowest. The relative abundance of Bacteroidetes (1.50%) was increased in the BF treatment, whereas Latescibacteria (0.11%) was decreased. There were significant differences in the relative abundance of Bacteroidetes and Latescibacteria between BF and NF treatments. In addition, BF significantly decreased the relative abundance of Zygomycota (2.18%). Compared with the NF treatment, the relative abundance of Chytridiomycota (0.01%) was significantly decreased in the BF treatment. BF changed the fungal community at the genus level and significantly decreased the relative abundance of Fusarium (5.83%). Compared with the NF treatment, the relative abundance of Mortierella (2.11%), Stachybotrys (0.90%) and Alternaria (0.01%), was decreased significantly in the BF treatment. The most important soil factor causing the change of bacterial community structure was pH, and the most important soil factor causing the change of fungal community structure was available P. Conclusion] Biochar-based fertilizers cause changes in soil biochemical environment, lead to changes in community structure, diversity of soil bacteria and fungi and then optimize soil ecology.