广东省本地油茶和引种油茶根际土壤微生物群落特征

Characteristics of microbial communities in rhizosphere soils of native and introduced Camellia oleifera in Guangdong Province

摘要:

【背景】近年来，油茶低效林面积较大，根际土壤微生物影响林木抗性和生长，对林业可持续发展具有重要意义。【目的】了解广东省本地油茶和引种油茶根际土壤微生物群落特征。【方法】利用高通量测序分析油茶根际土壤微生物群落组成。【结果】油茶根际土壤细菌有26门77纲201目377科593属676种，真菌有14门50纲121目266科502属631种。油茶根际土壤中的优势细菌为酸杆菌门和变形菌门，优势真菌为子囊菌门和担子菌门。两种油茶根际土壤微生物组成差异显著，本地油茶根际土壤的细菌多样性显著高于引种油茶。在门水平上，脱硫杆菌门细菌和罗兹菌门、被孢霉门真菌的相对丰度在两种油茶间差异显著，Amorphotheca在本地油茶根际土壤中特异性富集。两种油茶根际土壤细菌碳代谢相对丰度差异显著，真菌以腐生营养型为主，其次为病理营养型和共生营养型。本地油茶根际土壤中显著富集土壤腐生菌，而共生营养型真菌(尤其是丛枝菌根真菌)相对丰度(6.43%)显著低于引种油茶中(21.83%)。此外，有机质和养分含量是影响油茶根际土壤微生物群落的关键因子。【结论】本地油茶和引种油茶根际土壤微生物群落组成和结构差异显著，Amorphotheca和丛枝菌根真菌分别在本地油茶和引种油茶中显著富集，油茶根际土壤养分含量可能是影响其微生物群落组成的主要因子。

Abstract:

[Background] In view of the large area of Camellia oleifera with low efficiency, revealing the rhizosphere soil microorganisms affecting plant resistance and growth is essential for the sustainable development of forestry. [Objective] To understand the microbial community characteristics in the rhizosphere soils of native and introduced varieties of C. oleifera in Guangdong Province. [Methods] High-throughput sequencing was employed to analyze the microbial composition in the rhizosphere soil of C. oleifera. [Results] There were 676 species of bacteria belonging to 593 genera, 377 families, 201 orders, 77 classes, 26 phyla and 631 species of fungi belonging to 502 genera, 266 families, 121 orders, 50 classes, 14 phyla in the rhizosphere soil of C. oleifera. Acidobacteriota and Proteobacteria were the dominant bacteria and Ascomycota and Basidiomycota the dominant fungi. The rhizosphere soil microbial composition was significantly different between the native and induced varieties of C. oleifera. The bacterial diversity was significantly higher in the rhizosphere soil of the native variety than that of the introduced variety. At the phylum level, Desulfobacterota, Rozellomycota, and Mortierellomycota showed significantly different relative abundance between the two varieties. Amorphotheca was specifically enriched in the rhizosphere soil of the native variety. The relative abundance of carbon metabolism was significantly different between the rhizosphere soils of two varieties. Saprophytic fungi were dominant in the rhizosphere soil of C. oleifera, followed by pathotrophic and symbiotrophic fungi. Saprophytic fungi were significantly enriched in the rhizosphere soil of the native variety, while symbiotrophic fungi (especially arbuscular mycorrhizal fungi) had significantly lower relative abundance in the rhizosphere soil of the native variety than that of the introduced variety (6.43% vs. 21.83%). In addition, the organic matter and nutrients were key factors affecting the rhizosphere soil microbial community of C. oleifera. [Conclusion] The microbial community composition and structure in the rhizosphere soils of native and introduced C. oleifera were significantly different. Amorphotheca and arbuscular mycorrhizal fungi were significantly enriched in native and introduced C. oleifera, respectively. Nutrients may be the key factors affecting microbial communities in the rhizosphere soil of C. oleifera.