基于高通量测序的福建北部马铃薯晚疫病株根际土壤细菌群落分析

High-throughput sequencing of bacterial community in the rhizosphere soil of potato infected by late blight in northern Fujian province

摘要:

【背景】马铃薯晚疫病是一种由致病疫霉[Phytophthora infestans (Mont.) de Bary]引起的毁灭性病害，当环境条件适宜时，残留在土壤中的病原菌会侵染马铃薯植株导致病害的发生。【目的】明确健康马铃薯植株与发病植株的根际土壤细菌结构与多样性。【方法】采集马铃薯晚疫病发病地的健康植株根际土壤(M2J)和发病植株根际土壤(M2G)，对土样中的细菌群落进行基于Illumina Miseq测序平台的宏基因组高通量测序分析。【结果】发病植株根际土壤细菌的优质序列比健康植株少3.31% (1 747条)，OTU少24.58% (1 466个)。在门水平上，健康植株和发病植株根际土壤微生物组成相似，但相对丰度存在显著差异。其中发病后植株根际土壤菌群变形菌门(Proteobacteria)相对丰度增加17.70%，绿弯菌门(Chloroflexi)相对丰度增加了1.58%，而酸杆菌门(Acidobacteria)相对丰度降低了6.13%，放线菌门(Actinobacteria)相对丰度降低了4.28%，芽单胞菌门(Gemmatimonadetes)相对丰度降低了1.41%，疣微菌门(Verrucomicrobia)相对丰度降低了3.11%。在属水平上，发病植株根际的Rhodanobacter和鞘氨醇单孢菌属(Sphingomonas)相对丰度比健康植株增加了8.63%和3.51%；而Vicinamibacteraceae、norank_f__norank_o__Vicinamibacterales、norank_f__Gemmatimonadaceae、Chujaibacter和黄杆菌属(Flavobacterium)的相对丰度低于健康马铃薯植株。【结论】感染马铃薯晚疫病后的植株根际土壤细菌结构和多样性显著低于健康植株，细菌菌落多样性降低，且部分优势细菌门、属类群占比发生改变。

关键词:马铃薯;晚疫病;根际微生物;多样性

Abstract:

[Background] Potato late blight is a devastating disease caused by Phytophthora infestans(Mont.) de Bary.When environmental conditions are suitable,the P. infestans remaining in the soil will infect potato plants and cause late blight.[Objective] To clarify the bacterial community structure and diversity of the rhizosphere soil of healthy and diseased potato plants.[Methods] The rhizosphere soil samples of healthy (M2J) and diseased (M2G) potato plants in a potato field with late blight occurrence were collected.The metagenomic high-throughput sequencing was performed on the Illumina MiSeq platform to analyze the bacterial communities in the soil samples.[Results] The soil samples of diseased plants had 1 747 fewer high-quality sequences and 1 466 fewer OTUs than those of healthy plants.At the phylum level,the microorganisms in the rhizosphere soil had similar community composition while different abundance between healthy plants and diseased plants.After the occurrence of late blight,the relative abundance of Proteobacteria and Chloroflexi in the rhizosphere soil increased by 17.70% and 1.58%,respectively,while that of Acidobacteria,Actinobacteria,Gemmatimonadetes,and Verrucomicrobia decreased by 6.13%,4.28%,1.41%,and 3.11%,respectively.At the genus level,the relative abundance of Rhodanobacter and Sphingomonas in the rhizosphere of diseased plants increased by 8.63% and 3.51% compared with healthy plants;while the Vicinamibacteraceae,norank_f__norank_o__Vicinamibacterales,norank_f__Gemmatimonadaceae,Chujaibacter and Flavobacterium have lower species abundance than healthy plants.[Conclusion] The community structure and diversity of bacteria in the rhizosphere soil of plants infected with P. infestans were significantly lower than those of healthy plants,and the proportions of some dominant bacterial phyla and genera changed after disease occurrence.

Key words:potato;late blight;rhizosphere microorganisms;diversity