猕猴桃苗不同生长时期根际细菌群落结构分析

Analysis on rhizosphere bacterial community structure of Kiwifruit seedlings at different growth stages

【目的】探究猕猴桃苗不同生长时期根际土壤细菌群落组成及土壤养分间的相互关系。【方法】采用Illumina-MiSeq高通量测序研究猕猴桃苗不同生长阶段(生长前期、速生期、生长后期)的根际微生物群落结构组成及其多样性。运用CANOCO和R语言软件对土壤细菌群落与土壤环境因子间关系进行RDA和相关性热图分析。【结果】随着猕猴桃苗不断生长,土壤pH、速效N、速效P均出现先升高后降低趋势,速效K则随着猕猴桃苗生长逐渐降低;高通量测序共得到25822个细菌OTUs,分属于28门53纲172科226属,其中变形菌门(Proteobacteria,35.84%)、酸杆菌门(Acidobacteria,17.69%)、放线菌门(Actinobacteria,12.6%)是猕猴桃苗不同生长时期土壤的优势菌门;土壤细菌群落多样性指数和丰富度指数在猕猴桃生长初期与速生期和生长后期有显著差异;不同生长时期相对丰富度大于1%的菌门中,Cyanobacteria随着猕猴桃苗不断生长而逐渐减少,Actinobacteria、Latescibacteria、Acidobacteria的相对含量先升高后降低。【结论】猕猴桃苗根际土壤细菌群落组成和根际土壤养分发生变化受猕猴桃苗不同生长时期的影响,土壤根际主要养分和pH是影响土壤根际细菌群落结构比例变化的重要因子。

[Objective]The relationship between rhizosphere bacterial community structure and soil nutrients at different growth stages was explored.[Method]The structural composition and diversity of rhizosphere microbial community at different growth stages(early growth stage,rapid growth stage and late growth stage)of kiwifruit seedlings were studied by high-throughput sequencing of Illumina MiSeq.RDA and correlation heat map were obtained by CANOCO and R language software to analyze the relationship between soil bacterial community and soil environmental factors.[Result]With the growth of kiwifruit seedlings,the pH,available N and available P in soil show the trends of first increasing and then decreasing,while the available K gradually decreased.A total of 25822 bacterial OTUs were obtained by high-throughput sequencing,which individually belong to 226 genera,172 families,53 classes and 28 phyla.Among these bacteria,Proteobacte-ria(35.84%),Acidobacteria(17.69%)and Actinobacteria(12.6%)were the predominant phyla of kiwifruit seedlings in different growth time.The richness index and the diversity index of soil bacterial community at early growth stage were significantly rapid growth stage and late growth stage.Among the phyla whose relative abundance were high than 1%in different growth time,Cyanobacteria gradually decreased as the kiwifruit seedlings grew,as the relative contents of Actinobacteria,Latescibacteria and Acidobacteria increased first and then decreased.[Conclusion]The rhizosphere bacterial community composition and soil nutrients changed at different growth stages of kiwifruit seedlings.The main nutrients and pH of soil were important factors affecting the ratio soil bacterial community structure.