不同生长年限华重楼根际土壤微生物多样性研究

Microbial diversity in rhizosphere soil of Paris polyphylla var.chinensis in different growth years

为探究华重楼生长发育与土壤微生物群落结构变化的关系,该研究利用Illumina高通量测序技术对3年生、5年生、7年生、9年生等4个不同生长年限的华重楼根际土壤细菌16S rRNA和真菌18S序列进行测序分析。结果表明:(1)不同生长年限根际土壤中主要优势细菌均为变形菌门、酸杆菌门、放线菌门和绿弯菌门;优势真菌为子囊菌门、担子菌门与毛霉门。(2)不同生长年限华重楼根际土壤中细菌物种较真菌物种更丰富,多样化程度更高。细菌多样性随着华重楼生长年限的增加呈降低、升高、再降低的“И”型规律,最低点在第5年,最高点在第7年;真菌多样性则随着生长年限的增加呈先升高后下降的“Λ”型规律,最高点在第7年。细菌群落丰富度随着生长年限的增加呈先升高后下降的“Λ”型规律,第7年时丰富度最高;而真菌丰富度随着生长年限增长变化不大。(3)UPGMA聚类分析显示,随着生长年限的推进根际土壤微生物群落结构演变明显,细菌群落演变比较剧烈的时期是在定植后第7年,而真菌群落则在定植后第5年。(4)Spearman相关性分析发现,速效钾和全氮是影响华重楼根际土壤细菌组成的主要因子,全钾是影响真菌组成的主要因子。综上认为,不同生长发育时期的华重楼根际土壤微生物群落组成和结构不同,而第5至第7年是根际土壤微生物群落多样性发生重大变化的关键时期。

In order to explore the relationship between the growth of Paris polyphylla var.chinensis and the microbial community structure changes of the rhizosphere soil,the Illumina high-throughput sequencing technique was used to sequence the 16S rRNA gene of bacteria and 18S sequences of fungal at four different growth years,including three years,five years,seven years and nine years.The results were as follows:(1)Proteobacteria,Acidobacteria,Actinobacteria and Chloroflexi were dominant bacteria in the rhizosphere soil of P.polyphylla in different growth years.The dominant fungi phylas were Ascomycota,Basidiomycota and Mucoromycota.(2)The bacterium species in the rhizosphere of Paris polyphylla in different growth years were more abundant than fungus species,and the degree of diversification was higher.The bacterial diversity decreased first and increased,and then decreased again with the increase of growth years showed a pattern of“И”,and the lowest point was in the 5th year and the highest point was in the 7th year.The fungal diversity showed a pattern of“Λ”that first increased and then decreased with the increase of growth years,and the highest point was in the 7th year.The abundance of bacterial communities also showed a pattern of“Λ”that first increased and then decreased with the increase of growth years,and the highest point was also in the 7th year.The abundance of fungi did not change much as the year growing.(3)The UPGMA cluster analysis showed that the microbial community structure of the rhizosphere soil evolved significantly.The period that the bacterial community evolved more drastically was in the 7th year after planting,and the fungal community was in the 5th year.(4)Spearman correlation analysis found that total nitrogen and available potassium were the main factors affecting the composition of rhizosphere soil bacteria,and total potassium was the main factor affecting the composition of fungi.All the above results indicate that the composition and structure of the soil microbial community in the rhizosphere of wild P.polyphylla at different growth and development stages,and the 5th to the 7th year is a critical period for significant changes in the diversity of the soil microbial community.