基于高通量测序的樟子松叶部病害分析及叶际真菌群落多样性研究

High-throughput Sequencing Analysis of Leaf Disease of Pinus sylvestris var.mongolica and Diversity of Interleaf Fungal Communities

本文通过探究樟子松针叶不同发病程度的真菌群落多样性,为叶部病害的鉴定与防治提供有价值的信息。对樟子松针叶进行采样,通过高通量测序技术对所采集的样本进行真菌群落多样性分析。对相对丰度最高的真菌进行BLAST比对,构建系统发育树并进行分析。9个针叶样本中物种相对丰度主要分布于子囊菌门(Ascomycota)、担子菌门(Basidiomycota)之中,罗兹菌门(Rozellomycota)的真菌也极少量存在于针叶内。其中“门”水平上子囊菌门是相对丰度占比最大的优势门。优势科为球腔菌科,该科在3个不同林区重病样本W3-3、T78-3、T87-3中的占比分别为92%、92%、29%。研究发现,不同林区群落组成结构有一定差异,并且不同发病程度引起物种组成均匀度不同,表明发病后真菌的相对丰度既受到发病程度的影响也受到地理环境的影响。随着发病程度提升,D.septosporum占比提高。基于病原菌的ITS序列构建发育树,确认引起3个林区樟子松叶部病害松针红斑病的病原菌为松穴褥盘孢菌。

This paper investigates the fungal community diversity of Pinus sylvestris var.Mongolica needles under different degrees of disease,which can provide valuable information for the identification and control of foliar diseases.The needles of Pinus sylvestris var.mongolica were sampled,and the collected samples were analyzed for fungal community diversity by high-throughput sequencing technology.The fungi with high relative abundance were compared by BLAST,and phylogenetic trees were constructed and analyzed.The relative abundance of species in the nine conifer samples was mainly distributed among Ascomycota and Basidiomycota,and a minimal amount of Rozellomycota fungi were also present in the conifer.The Ascomycota was the dominant phylum with the largest relative abundance at the"phylum"level.The Mycosphaerellaceae accounted for 92%,92%,and 29%of the heavy disease samples W3-3,T78-3,and T87-3 from three different forestry sites,respectively.It was found that there were some differences in the community composition structure of different forest sites,and different levels of incidence caused different evenness of species composition,indicating that the relative abundance of fungi after incidence was influenced by both the level of incidence and the geographical environment.The percentage of Dothistroma septosporum increased as the degree of incidence increased.A phylogenetic tree was constructed based on the ITS sequences of the pathogenic fungus,and the pathogenic fungus causing the Dothistroma pini Hulbary in the foliar parts of camphor pine in the three forest sites was confirmed to be D.septosporum.