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【目的】为表征长达35年轮作与施肥条件下东北黑土微生物群落特征,解析长期施肥及作物对土壤微生物丰度和群落结构的影响,探讨东北黑土微生物群落变化与施肥及不同作物间的相互关系,为进一步改良耕作制度与施肥方式提供依据。【方法】依托黑龙江省农业科学院长期定位试验站,选取玉米和大豆两种作物季的4个不同施肥处理:不施肥处理(CK)、有机肥处理(M)、无机肥处理(NPK)和有机肥配施无机肥处理(MNPK)的耕层土壤为研究对象,处理前加字母m表示玉米季样品,加字母s表示大豆季样品。借助Illumina Miseq高通量测序平台和Real-time PCR技术,以16S rRNA基因为分子标靶,研究作物与施肥方式对黑土中微生物群落结构和丰度的影响,分析群落变化与土壤化学性质的相关性。【结果】玉米季土壤16S rRNA基因拷贝数(6.32×10~8—8.83×10~8/ng DNA)比大豆季的低(0.96×10~9—2.30×10~9/ng DNA);玉米季土壤微生物多样性(ACE指数为3 674.58—4 034.84)也低于大豆季(ACE指数为4 167.47—4 887.36);玉米季的细菌丰度以Acidobacteria(24.47%—27.90%)最高,而大豆季丰度最高的是Proteobacteria(27.78%—34.40%),Bacteroidetes和Actinobacteria丰度在两季作物中差异明显。同一作物季的有机肥无机肥配施处理的16Sr RNA基因拷贝数高于无机肥处理,且有机肥配施无机肥处理的微生物α多样性指数也比无机肥处理的高(sMNPK的Chao1指数比sNPK高出11.89%);不同施肥处理之间群落组成存在差异,Alphaproteobacteria在sMNPK和sNPK处理的相对丰度分别比sCK增加3.31%、5.24%;Gammaproteobacteria在sMNPK和sNPK处理均比sCK处理增加1.72%和1.2%,二者相对丰度变化大。相关性分析显示,16Sr RNA基因拷贝数与土壤硝态氮和速效钾正相关;微生物菌落多样性指数与土壤全氮、硝态氮、铵态氮、有效磷和速效钾等化学性质密切相关。【结论】东北黑土不同作物季和不同施肥均会影响土壤微生物丰度、α多样性和群落结构。有机肥无机肥配施能够有效改变微生物群落结构,提高微生物的丰度和多样性,并提高土壤p H,减缓土壤酸化。
【Objective】 In order to characterize the microbial community characteristics of black soil in Northeast China under 35 years of rotation and fertilization, the effects of long-term fertilization and soil microbial abundance and community structure were analyzed, and the changes of microbial community and fertilization in Northeast China were discussed. Relationship, provide the basis for further improvement of farming system and fertilization mode. 【Method】 Four different fertilization treatments of corn and soybean were selected based on the long-term experiment station of Heilongjiang Academy of Agricultural Sciences: CK, M, NPK and organic Topsoil with fertilizers and inorganic fertilizers (MNPK) was used as the study object. Before treatment, the letter m was used to represent the maize season sample and the letter s to indicate the soybean season sample. Using Illumina Miseq high-throughput sequencing platform and Real-time PCR technology, the 16S rRNA gene was used as a molecular target to study the effects of crop and fertilization on microbial community structure and abundance in black soil, and to analyze the correlation between community change and soil chemical properties Sex. 【Result】 The results showed that 16S rRNA gene copy number (6.32 × 10 ~ 8-8.83 × 10 ~ 8 / ng DNA) in maize field was lower than that in soybean season (0.96 × 10 ~ 9-2.30 × 10 ~ 9 / ng DNA) Soil microbial diversity (ACE index: 3 674.58-4 034.84) was also lower than that in soybean season (ACE index was 4 167.47-4 887.36); the bacterial abundance in maize was highest in Acidobacteria (24.47% -27.90%), while soybean The highest seasonal abundance was Proteobacteria (27.78% -34.40%). The abundances of Bacteroidetes and Actinobacteria were significantly different between the two seasons. The copy number of 16S rRNA gene in the same crop season was higher than that of inorganic fertilizers, and the α diversity index of organic fertilizer treated with inorganic fertilizers was also higher than that of inorganic fertilizers (Chao1 index of sMNPK sP and sNPK, respectively. The relative abundance of Alphaproteobacteria in sMNPK and sNPK was increased by 3.31% and 5.24%, respectively, compared with that of sCK. Gammaproteobacteria increased 1.72% in sMNPK and sNPK compared with sCK, And 1.2%, the relative abundance of both changes. Correlation analysis showed that 16Sr RNA gene copy number was positively correlated with soil nitrate nitrogen and available potassium. The diversity index of microbial colonies was closely related to the chemical properties of soil total nitrogen, nitrate nitrogen, ammonium nitrogen, available phosphorus and available potassium. 【Conclusion】 Different crop seasons and different fertilizations of black soil in Northeast China affect soil microbial abundance, α diversity and community structure. Fertilizer application of organic manure can effectively change the microbial community structure, increase the abundance and diversity of microorganisms, increase soil p H and slow soil acidification.