Multiple factors drive the abundance and diversity of the diazotrophic community in typical farmland soils of China
Multiple factors drive the abundance and diversity of the diazotrophic community in typical farmland soils of China
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DOI：
10.1093/femsec/fiz113
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发表时间：
2019-08-01
影响因子：
4.2
通讯作者：
He, Ji-Zheng
中科院分区：
文献类型：
--
作者：
Han, Li-Li;Wang, Qing;He, Ji-Zheng
生物固氮通过将大气中的N-2转化为土壤中的植物有效氮，在氮循环中起着重要作用。但固氮菌在不同类型土壤中的活性及其分布规律还有待进一步研究。采用定量聚合酶链反应（PCR）、乙炔还原法和nifH基因MiSeq测序等方法，对152个高地土壤样品的固氮菌丰度、固氮酶活性、多样性和群落组成进行了研究。结果表明，3种土壤类型的固氮菌丰度和固氮酶活性存在差异。重氮营养菌群落主要由慢生根瘤菌、固氮菌、黏菌、脱硫弧菌和甲基杆菌组成。共生固氮菌慢生根瘤菌在土壤中分布广泛，而自生固氮菌的分布变异较大，受多种因素影响较大。作物类型和土壤性质直接影响固氮菌α多样性，而土壤性质、气候因子和空间距离共同影响固氮菌群落。网络结构是完全不同的所有三种类型的土壤中，最复杂的相互作用观察到红壤。这些结果表明，固氮菌在3种土壤类型中的活动和分布不同，它们在中国农业土壤氮素输入中所起的作用也不同，受多种环境因素的影响。
Biological nitrogen fixation plays an important role in nitrogen cycling by transferring atmospheric N-2 to plant-available N in the soil. However, the diazotrophic activity and distribution in different types of soils remain to be further explored. In this study, 152 upland soils were sampled to examine the diazotrophic abundance, nitrogenase activity, diversity and community composition by quantitative polymerase chain reaction, acetylene reduction assay and the MiSeq sequencing of nifH genes, respectively. The results showed that diazotrophic abundance and nitrogenase activity varied among the three soil types. The diazotrophic community was mainly dominated by Bradyrhizobium, Azospirillum, Myxobacter, Desulfovibrio and Methylobacterium. The symbiotic diazotroph Bradyrhizobium was widely distributed among soils, while the distribution of free-living diazotrophs showed large variation and was greatly affected by multiple factors. Crop type and soil properties directly affected the diazotrophic alpha-diversity, while soil properties, climatic factors and spatial distance together influenced the diazotrophic community. Network structures were completely different among all three types of soils, with most complex interactions observed in the Red soil. These findings suggest that diazotrophs have various activities and distributions in the three soil types, which played different roles in nitrogen input in agricultural soil in China, being driven by multiple environmental factors.