生姜根系不同生态位细菌群落多样性特征、组成及结构差异

生姜作为常见的调味品和传统中药材，是我国重要的经济作物之一。作为取食部分的生姜块茎与根系直接相连，其产量、品质与根相关细菌群落密切相关。然而，关于生姜根系微环境中细菌群落的特点仍鲜有报道，土壤环境能否衍生出宿主特异性内生菌群落尚不清楚。以生姜根系不同生态位细菌群落为研究对象，采用高通量测序技术，对非根际、根际及根内细菌进行16S rRNA基因测序。结果表明，不同生态位细菌群落多样性存在显著差异，其中非根际及根际细菌群落多样性(Shannon index, Observed species, Faith′s PD)显著高于内生菌群落。同时，各生态位共现网络稳定性和复杂度表现为非根际>根际>根内细菌群落。而在组成上，细菌群落在不同生态位差异显著(R²=0.57,P=0.001)。其中变形菌门(Proteobacteria)是根内的优势门，该门类下假单胞菌属(Pseudomonas)、短波单胞菌属(Brevundimonas)、寡养单胞菌属(Stenotrophomonas)及泛菌属(Pantoea)在根内显著富集。在根际细菌中，拟杆菌门(Bacteroid...

Characteristics of bacterial community diversity, composition and structure in different niches of ginger root

Ginger, as a common condiment and traditional Chinese medicine, is one of the important economic plants in China. The plump tuber as a feeding part is closely related to the root system, so the yield and quality of tuber is also deeply affected by the bacteria related to root. However, there are few reports on bacteria in ginger root micro environment, and it is unclear whether the soil environment can derive host specific endophytes. In this research, the bacterial community composition in different niches of ginger (bulk soil, rhizosphere soil, and root) were explored and characterized. The results showed that the alpha diversity (Shannon index, Observed species, and Faith''s PD) of bulk soil bacteria and rhizosphere bacteria was significantly higher than that of endophytes. The stability and complexity trend of niche co-occurrence network was bulk soil bacteria > rhizosphere bacteria > endophytes. Bacterial community composition could be significantly separated by niche (R²=0.57, P=0.001). Proteobacteria was significantly enriched in roots. Under this phylum, the dominant bacteria were Pseudomonas, Brevundimonas, Stenotrophomonas and Pantoea etc. Among rhizosphere bacteria, Bacteroidetes and Firmicutes were significantly enriched. The abundance advantage was mainly contributed by Sphingosphaga, Bacillus and Chryseobacterium. Bacterial communities were affected by some soil environmental factors. Soil pH was closely related to bacterial communities in bulk soil. Available phosphorus was significantly related to the composition of rhizosphere bacterial communities, while there was no factor associated with endophytes. Further traceability analysis showed that 42.8% of rhizosphere bacteria originated from bulk soil, while 47.3% of endophytes originated from rhizosphere, which proved that there was niche level transmission in ginger root related bacterial community. In short, the bacterial diversity, stability and categories of bacterial communities in different niches of roots were significantly different, which reflects the screening and filtration effect of roots. By analyzing the composition of bacterial communities in different root niches, the similarities and differences of bacterial communities in different root niches were clarified, which laid a foundation for the development and utilization of ginger root related bacterial communities.