王香生, 连延浩, 郭辉, 任永哲, 辛泽毓, 林同保, 王志强. 小麦红花间作系统根际微生物群落结构及功能分析[J]. 中国生态农业学报 (中英文), 2023, 31(4): 516−529. DOI: 10.12357/cjea.20220354
引用本文: 王香生, 连延浩, 郭辉, 任永哲, 辛泽毓, 林同保, 王志强. 小麦红花间作系统根际微生物群落结构及功能分析[J]. 中国生态农业学报 (中英文), 2023, 31(4): 516−529. DOI: 10.12357/cjea.20220354
WANG X S, LIAN Y H, GUO H, REN Y Z, XIN Z Y, LIN T B, WANG Z Q. Effects of wheat/safflower intercropping on rhizosphere microbial community function and structure[J]. Chinese Journal of Eco-Agriculture, 2023, 31(4): 516−529. DOI: 10.12357/cjea.20220354
Citation: WANG X S, LIAN Y H, GUO H, REN Y Z, XIN Z Y, LIN T B, WANG Z Q. Effects of wheat/safflower intercropping on rhizosphere microbial community function and structure[J]. Chinese Journal of Eco-Agriculture, 2023, 31(4): 516−529. DOI: 10.12357/cjea.20220354

小麦红花间作系统根际微生物群落结构及功能分析

Effects of wheat/safflower intercropping on rhizosphere microbial community function and structure

  • 摘要: 研究小麦红花间作系统作物根际土壤微生物群落结构及功能变化, 对后期构建合理的小麦红花间作种植模式和地区适宜性评价具有重要意义。本研究在田间设置小麦红花间作(2∶1)模式, 以小麦单作、红花单作为对照, 基于Illumina Miseq高通量测序平台研究了小麦红花根际土壤细菌和真菌群落结构特征和功能变化, 在成熟期, 分别测定小麦红花产量。结果表明: 小麦红花间作土地当量比为1.01, 间作优势并不明显; 小麦、红花根际微生物多样性指数分析结果表明, 间作提高了小麦根际细菌多样性和真菌的丰富度, 但显著降低了小麦根际细菌的丰富度和真菌多样性; 间作显著提高了红花根际细菌的多样性, 但降低了红花根际真菌的多样性及细菌和真菌的丰富度。主坐标分析(PCoA)和群落均衡性分析结果表明, 间作显著改变了红花根际微生物群落结构。小麦红花根际优势细菌门为变形菌门、酸杆菌门和拟杆菌门, 在单作小麦、间作小麦、单作红花和间作红花中平均相对丰度总占比分别为65.94%、70.57%、71.39%和70.07%, 优势真菌为子囊菌门、担子菌门, 平均相对丰度总占比分别为75.99%、68.17%、93.23%和69.88%。间作显著提高了红花根际酸杆菌门、Rokubacteria以及真菌的被孢霉门的相对丰度, 对小麦各菌门并未造成显著影响。功能预测结果表明, 间作显著提高了红花根际好氧氨氧化、硝化作用、发酵、硝酸盐还原等养分循环过程, 结合相关性分析结果发现细菌MND1属与这些过程显著正相关, 且其相对丰度在红花根际表现为间作显著高于单作。此外, 间作显著提高了红花根际丛枝菌根功能基因的相对丰度, 降低了植物病原菌类功能基因的相对丰度; 在属水平, 间作显著提高了红花根际被孢霉属、Wickerhamomyces等有益菌属的相对丰度, 显著降低了镰刀菌属、链格孢属致病真菌属的相对丰度。共现网络分析结果表明, 间作可一定程度上提高小麦根际微生物网络的复杂性, 降低红花根际微生物网络的复杂性; 此外, 镰刀菌属位于红花根际微生物网络的中心, 间作可通过影响红花根际微生物间的相互作用明显降低镰刀菌属的数量。综上, 小麦红花间作体系中, 处于竞争劣势的红花可通过改善根际微生物群落组成, 提高根际养分循环过程, 进而缓解在养分等资源竞争上的不利地位; 此外, 间作可显著降低红花根际致病类病原菌的相对丰度, 对减少红花病害的发生及土壤中致病菌总量均具有重要意义。

     

    Abstract: Studying the structure and function of rhizosphere soil microbial communities in wheat/safflower intercropping systems is of great significance for the construction of appropriate wheat/safflower intercropping patterns and regional suitability evaluation. In this study, a wheat/safflower intercropping (2∶1) pattern was set in the field, and wheat monoculture and safflower monoculture were used as controls, based on Illumina Miseq high-throughput sequencing platform. The community structure and functional changes of bacteria and fungi in the rhizosphere soil of wheat/safflower intercropping were studied, and safflower and wheat yield were measured at maturity. The results showed that the wheat/safflower intercropping land equivalent ratio was 1.01, the intercropping advantage was not obvious. The wheat and safflower intercropping increased the bacterial diversity and fungal richness of the wheat rhizosphere, but significantly decreased the bacterial richness and fungal diversity. Intercropping significantly increased bacterial diversity in the rhizosphere of safflower but decreased fungal diversity and bacterial and fungal richness in the rhizosphere of safflower. A principal coordinate analysis and equilibrium analysis of the rhizosphere soil microbial community showed that intercropping significantly changed the microbial community structure in the rhizosphere of safflower. Proteobacteria, Acidobacteria, and Bacteroidetes were the dominant bacteria in the rhizospheres of wheat and safflower, their average total proportions of relative abundances were 65.94%, 70.57%, 71.39%, and 70.07% for monocultured wheat, intercropped wheat, monocultured safflower and intercropped safflower, respectively. Ascomycota and Basidiomycota were the dominant fungi, the their average total proportions of relative abundances were 75.99%, 68.17%, 93.23% and 69.88% for monocultured wheat, intercropped wheat, monocultured safflower and intercropped safflower, respectively. Intercropping significantly increased the relative abundance of Acidobacteria, Rokubacteria, and Mortierellomycota in the rhizosphere of safflower, while it had no significant effect on wheat. Our functional prediction results showed that intercropping significantly improved nutrient cycling processes, such as ammonia oxidation, nitrification, fermentation, and nitrate reduction in the rhizosphere of safflower. Combined with the correlation analysis results, MND1 genus of bacteria was significantly positively correlated with these processes, and its relative abundance in the rhizosphere of safflower was significantly higher in intercropping than in the monoculture. In addition, intercropping significantly increased the relative abundance of arbuscular mycorrhizal functional genes in the rhizosphere of safflower, and significantly decreased the relative abundance of plant pathogenic functional genes. At the genus level, intercropping significantly increased the relative abundance of beneficial bacteria, such as Moralella and Wickerhamomyces, in the rhizosphere of safflower. The relative abundances of pathogenic fungi belonging to Fusarium and Alternaria was significantly decreased. In conclusion, under a wheat/safflower intercropping system, safflower at a competitive disadvantage can improve the rhizosphere microbial community composition and nutrient cycling process, thus alleviating the disadvantage of nutrient competition. The co-occurrence network analysis results showed that intercropping could improve the complexity of the rhizosphere microbial network of wheat and reduce the complexity of the rhizosphere microbial network of safflower, to some extent. In addition, Fusarium is located in the center of the rhizosphere microbial network of safflower, and intercro