The microbial community of fruit peel tissues helps to improve fruit quality and resistance to pathogens. There are few reports on the community structure and diversity of endophytic microbes of pitaya peel tissues. This study analyzed the composition and diversity of the endophytic microbial communities in the peel tissues of young healthy fruits and diseased fruits at the early stage of canker disease, and predicted microbial functions to understand the characteristics, through Illumina MiSeq high-throughput sequencing technology. The results showed that there was no significant difference in the diversity and structure of the endophytic bacterial and fungal communities between healthy and diseased peel tissues of pitaya young fruits. In the peel tissues of healthy fruits, Proteobacteria, Actinobacteriota, Firmicutes, Bacteroidota, Deinococcota, Desulfobacteriota and Chloroflexi were the dominant bacterial phyla, and Ascomycota, unclassified_k_Fungi, Basidiomycota and Mucoromycota were the dominant fungal phyla. In the early stage of canker disease, the bacterial phyla Proteobacteria, Actinobacteriota and Deinococcota, as well as fungal phylum Ascomycota, significantly decreased, while bacterial phylum Desulfobacteriota and fungal phylum unclassified_k_Fungi significantly increased in average relative abundance. Compared with the healthy fruits peel, with differences in the proportion of the above microbes, the expression levels of chemoheterotrophy, aerobic chemoheterotrophy, methylotrophic and methanol oxidation functions of endophytic bacteria in diseased fruits peel significantly decreased, the proportion of potentially_pathogenic groups of endophytic bacteria significantly increased, the proportion of saprotroph, pathotroph, pathotroph symbiotroph of endophytic fungi significantly decreased, and the proportion of unknown trophic fungi significantly increased. The results would provide biological information on the endophytic microbes in pitaya fruits peel, to reveal the role in the occurrence of pitaya canker disease and provide theoretical basis for utilizing the function of beneficial microorganisms.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |