Han Feng-Yi, Zhang Yi-Rong, Wang Si-Rong, Yang Zhi-Jie, Zheng Yong, Deng Mi-Lin, He Ji-Zheng, Lin Yong-Xin
1 Cultivation Base of State Key Laboratory for Subtropical Mountain Ecology, Fuzhou 350117, China.
2 School of Geographical Sciences, Fujian Normal University, Fuzhou 350117, China.
Ying Yong Sheng Tai Xue Bao. 2024 Jun;35(6):1681-1688. doi: 10.13287/j.1001-9332.202406.011.
Rhizosphere is a vital area for substance exchange and energy transfer between roots and soil microorganisms. Therefore, diazotrophs in the rhizosphere play a pivotal role in facilitating plant nitrogen acquisition. We investigated the variability in the abundance and community structure of soil diazotrophs and the influencing factors across rhizosphere soils of in three locations: Baisha State-owned Forest Farm in Longyan City (BS), Sanming Forest Ecosystem and Global Change Research Station (SM), and Wuyishan National Forest Park in Nanping City (WYS), located in the western region of Fujian Province, quantified the diazotrophic abundance by using real-time quantitative PCR, and assessed the community structure by high-throughput sequencing. The results showed that soil pH, C:N ratio, and C:(N:P) stoichiometry in SM were notably lower compared to those in BS and WYS. In SM, the abundance of the gene was 6.38×10 copies·g, significantly lower than 1.35×10 copies·g in BS and 1.10×10 copies·g in WYS. Additionally, α diversity index of diazotrophs was lower in SM compared to BS and WYS, while the community structure of diazotrophs in rhizosphere soils of BS and WYS was similar, which differed significantly from that in SM. The diazotrophic sequences in the three forest farms could be divided into 5 phylum, 8 classes, 15 orders, 23 families and 33 genera, with Proteobacteria, α-proteobacteria, and as the dominant phylotypes. Soil pH, available phosphorus, NO-N and C:(N:P) ratio were identified as significant factors influencing both the abundance and community structure of genes, with soil pH performing the greatest. Taken together, there were spatial variations in the distribution of diazotrophic abundance and community structure in rhizosphere soils, with soil pH as the primary driving factor.
根际是根系与土壤微生物之间进行物质交换和能量传递的重要区域。因此，根际中的固氮菌在促进植物氮素获取方面发挥着关键作用。我们调查了福建省西部三个地点（龙岩市白沙国有林场（BS）、三明森林生态系统与全球变化研究站（SM）、南平市武夷山国家森林公园（WYS））根际土壤中土壤固氮菌的丰度和群落结构的变异性及其影响因素，采用实时定量PCR定量固氮菌丰度，通过高通量测序评估群落结构。结果表明，与BS和WYS相比，SM的土壤pH值、碳氮比和碳:（氮:磷）化学计量显著较低。在SM中，nifH基因的丰度为6.38×10⁵拷贝·g⁻¹，显著低于BS的1.35×10⁶拷贝·g⁻¹和WYS的1.10×10⁶拷贝·g⁻¹。此外，SM中固氮菌的α多样性指数低于BS和WYS，而BS和WYS根际土壤中固氮菌的群落结构相似，与SM的显著不同。三个林场的固氮菌序列可分为5个门、8个纲、15个目、23个科和33个属，以变形菌门、α-变形菌纲和弗兰克氏菌属为优势系统发育型。土壤pH值、有效磷、硝态氮和碳:（氮:磷）比被确定为影响nifH基因丰度和群落结构的显著因素，其中土壤pH值的影响最大。综上所述，固氮菌丰度和群落结构在根际土壤中的分布存在空间变异，土壤pH值是主要驱动因素。
