康定冬虫夏草子囊孢子弹射期土壤细菌群落研究

Study on the Soil Bacterial Community of Ophiocordyceps sinensis During Ascospores Ejection in Kangding

为探究四川甘孜藏族自治州康定市冬虫夏草(Ophiocordyceps sinensis)在子囊孢子弹射期土壤理化因子和细菌群落组成,找出可能影响冬虫夏草子囊孢子弹射的关键菌群,为更好开展冬虫夏草人工抚育奠定基础。以康定冬虫夏草人工抚育基地土壤为研究对象,对冬虫夏草虫体周际土壤和对照土壤进行高通量测序和土壤理化因子分析。结果显示:冬虫夏草虫体周际有机质(OM)、总氮(TN)、碱解氮(AN)、pH、镉(Cd)、铅(Pb)、汞(Hg)和砷(As)均显著低于对照地(P<0.05),有相对更高含量的速效钾。样品细菌群落划分为33门、126纲、230目、375科、592属。门水平上,Proteobacteria、Acidobacteria和Actinobacteria为相对丰度最高的前三个门,三者占样品相对丰度比78.29%~81.47%,且Proteobacteria与Hg、AN和OM呈正相关;Acidobacteria与AP呈正相关,与OM、TN、Pb和As呈负相关;Actinobacteria与AK和OM呈正相关。属水平上,Rhodoplanes、DA101(未命名)、Candidatus Solibacter、Ralstonia、Ochrobactrum、Rhodococcus等无论是否在冬虫夏草产地都有分布,以Rhodoplanes在J1、J2和J3中平均相对丰度分别为6.33%、6.28%和4.41%,显著高于J4的1.96%。研究结果对冬虫夏草子囊孢子弹射期其虫体周际土壤重金属、常规理化性质及土壤细菌组成有了进一步的认识,对更好开发康定市冬虫夏草资源具有重要意义。

In order to explore the soil bacterial communities and soil physiochemical properties associated with Ophiocordyceps sinensis in Kangding during their ascospore ejection period and also with the aim to lay a foundation for better artificial cultivation of O.sinensis.The rhizosphere soils of O.sinensis artificial raising base of Kangding were used as the research object to perform the high-throughput sequencing and soil physicochemical factor analysis.The results showed that the content of organic matter(OM),total nitrogen(TN),available nitrogen(AN),pondus hydrogenii(pH),cadmium(Cd),plumbum(Pb),hydrargyrum(Hg)and arsenic(As)in the rhizosphere soils of O.sinensis were significantly lower than those in control soils(P<0.05),while relatively more AK were detected in O.sinensis rhizosphere soils.The bacterial community of the samples was divided into 33 phyla,126 classes,230 orders,375 families and 592 genera.At phylum level,Proteobacteria,Acidobacteria and Actinoacteria were the first three abundant phyla and their relative abundance accounted for 78.29%to 81.47%.Proteobacteria was positively correlated with Hg,AN and OM.Acidobacteria was positively correlated with AP and negatively correlated with OM,TN,Pb and As.Actinobacteria was positively correlated with AK and OM.At genus level,whether in the periphery of O.sinensis or not,Rhodoplanes,DA101,Candidatus Solibacter,Ralstonia,Ochrobactrum,Rhodococcus and so on were all distributed.The average relative abundances of Rhodoplanes in J1,J2 and J3 were 6.33%,6.28%and 4.41%respectively,which were significantly higher than that in J4(1.96%).The results of this study provided a further understanding of the soil heavy metals,conventional soil properties and soil bacterial community of O.sinensis during the ascospore ejection period,which is of great significance for the better development of O.sinensis resources in Kangding.