降香黄檀内生细菌多样性研究

The diversity of endophytic bacteria in Dalbergia odorifera

【目的】降香黄檀是我国濒危树种,降香黄檀的高效培育一直是国内外研究的热点问题。本研究旨在为合理利用降香黄檀内生细菌资源提供科学依据,因此对降香黄檀内生细菌的群落结构及多样性进行探讨。【方法】采用高通量测序技术分析降香黄檀内生细菌的群落结构及多样性,同时测定并分析了降香黄檀心材边材的理化性质,包括含水率、pH值、灰分含量、热水抽提物含量、钙元素含量、钾元素含量和镁元素含量。【结果】经过测序共获得301585条序列,有效序列平均长度为447.5 bp;得到4678个OTUs,分属24门51纲104目200科329属。在门的水平上,心材优势菌为变形菌门和蓝细菌门,边材优势菌为变形菌门。在属的平上,心材优势菌为肠杆菌属,边材优势菌为肠杆菌属和不动杆菌属。丰度指数、香侬指数和辛普森指数的结果显示降香黄檀心材内生细菌的多样性大于边材。降香黄檀的内生细菌无论是数量还是多样性,在心材和边材上都存在差异。研究发现降香黄檀心材和边材灰分含量、热水提取物、pH值、Ca含量和K含量都存在明显差异。【结论】降香黄檀内生细菌的群落结构及多样性,心材均大于边材;引起降香黄檀内生细菌群落结构差异的主要木材环境因子有灰分含量、热水提取物、pH值、Ca含量和K含量;降香黄檀的各项理化性质中对其内生细菌群落结构影响较大的是含水率和pH值,其中pH值影响最大。

【Objective】Dalbergia odorifera is an endangered tree species in China.Efficient cultivation of D.odorifera has always been a hot research topic at home and abroad.In order to provide a scientific basis for the rational use of D.odorifera endophytic bacteria resources,the community structure and diversity of D.odorifera endophytic bacteria were discussed.【Method】High-throughput sequencing technology was used to analyze the community structure and diversity of D.odorifera endophytic bacteria.At the same time,the physical and chemical properties of D.odorifera heartwood and sapwood were determined and analyzed,including water content,pH,ash content,hot water extract content,calcium content,potassium content and magnesium content.【Result】After sequencing,a total of 301,585 sequences were obtained,with an average effective sequence length of 447.5 bp;4678 OTUs were obtained,belonging to 24 phyla,51 classes,104 orders,200 families and 329 genera.At the phylum level,the dominant bacteria in the heartwood are the Proteobacteria and Cyanobacteria.At the genus level,the dominant bacteria in the heartwood are Enterobacter,and the dominant bacteria in the sapwood are Enterobacter and Acinetobacter.The results of Chao 1,Shannon,and Simpson showed that the diversity of endophytic bacteria in the heartwood of D.odorifera was greater than that of the sapwood.The number and diversity of endophytic bacteria in D.odorifera are different in heartwood and sapwood.The study found that D.odorifera heartwood and sapwood ash content,hot water extract,pH,Ca content and K content are significantly different.【Conclusion】D.odorifera endophytic bacterial community structure and diversity,heartwood is larger than sapwood,the main wood environmental factors that cause differences in D.odorifera endophytic bacteria community structure are ash content,hot water extract,pH,and Ca Content and K content.Among the various physical and chemical properties of D.odorifera,the most significant impact on the structure of its endophytic bacterial community is the water content and pH value,of which pH value has the greatest impact.