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.
