不同栽培模式对辣椒根际连作土壤微生物区系和酶活性的影响

目的揭示玉米大豆间作体系种间互作下根际微生物群落功能和结构的变化。方法通过玉米间作大豆田间小区试验，采用BIOLOG和高通量测序技术对玉米抽雄期(大豆花荚期)的根际微生物群落进行功能和结构解析。结果(1) 大豆根际微生物群落碳源代谢功能多样性高于玉米。与各自单作相比，间作玉米Shannon指数显著提高3.5% (P<0.05)，Simpson指数显著降低13.1% (P<0.05)；间作大豆Simpson指数显著提高7.8% (P<0.05)，具有趋同性。(2) 与单作相比，玉米大豆间作体系中玉米根际可检测细菌总量显著增加 (P<0.05)，大豆根际可检测细菌总量呈降低趋势 (P>0.05)；物种多样性和遗传多样性变化不显著 (P>0.05)；玉米和大豆的根际细菌群落均出现新种属，菌种组成趋同与变异共存。(3) 与单作相比，玉米大豆间作体系中根际装甲菌门 (Armatimonadetes) 的相对丰度显著增加 (P<0.05)，其余优势类群无显著差异 (P>0.05)。受玉米大豆互作影响，酸杆菌门 (Acidobacteria) 的相对丰度由差异不显著 (P>0.05) 变为显著 (P<0.05)，芽单胞菌门 (Gemmatimonadetes)、芽单胞菌属 (Gemmatimonas)、Gaiella、纤线杆菌属(Ktedonobacter) 和罗河杆菌属(Rhodanobacter) 的相对丰度则由差异显著 (P<0.05) 变为不显著 (P>0.05)。结论玉米间作大豆改变玉米和大豆的根际微生物群落功能和结构，趋同与趋异共存，以趋同性为主。

Structural and functional microbial diversity along a eutrophication gradient of interconnected lakes undergoing anthropopressure

PurposeTo reveal the change rules of rhizosphere microbial community function and structure under the interaction of two crops in the intercropping system of maize (Zea mays L.) and soybean (Glycine max). MethodFunction and structure of rhizosphere microbial communities in maize tasseling stage/soybean flowering pod stage were analyzed synchronously by BIOLOG and high throughput sequencing technology under maize and soybean intercropping field plot experiment. Results1) Microbial community carbon source metabolic function diversity of soybean rhizosphere was higher than that of maize. Compared with monoculture of each other, Shannon index of intercropped maize was significantly increased by 3.5% (P<0.05), Simpson index significantly decreased by 13.1% (P<0.05), while Simpson index of intercropped soybean was significantly increased by 7.8% (P<0.05), which made the each other became similar. 2) Compared with monoculture, the total amount of detectable bacteria in maize rhizosphere increased significantly after intercropping (P<0.05), while the total amount of detectable bacteria in soybean showed a decreasing trend (P>0.05). However, there was no significant change in species diversity and genetic diversity (P>0.05). Under the influence of interspecific interaction, there were new species in the rhizosphere bacterical community of both species. As for species composition convergence and variation coexist. 3) Compared with monoculture, the relative abundance of Armatimonadetes in rhizosphere increased significantly in maize and soybean intercropping system (P<0.05), but there was no significant difference in other dominant groups (P>0.05). The relative abundance of Acidobacteria changed from insignificant (P>0.05) to significant (P<0.05) under the interaction of maize and soybean, while the relative abundance of Gemmatimonadetes, Gemmatimonas, Gaiella, Ktedonobacter and Rhodanobacter changed from significant (P<0.05) to insignificant (P>0.05) under the interaction of maize and soybean. ConclusionThe function and structure of rhizosphere microbial community were changed by maize and soybean intercropping. Convergence coexists with divergence, mainly with convergence.