Characterization of spatio-temporal variations in carposphere microbial diversity of olive in Longnan, China.

The fruit surface microbiome influences quality formation and disease occurrence, yet carposphere microbial diversity and functions remain poorly studied. This study employed 16S rRNA and ITS high-throughput sequencing technology to investigate the spatiotemporal variation patterns of the olive carposphere microbiome in Longnan City, Gansu Province, China, with respect to cultivars, maturity stages, and geographical locations. The results showed that the olive carposphere bacterial communities were dominated by Proteobacteria, and their abundance increased with fruit ripening. Methylobacterium-Methylorubrum showed significant enrichment at the mature stage, while Streptococcus served as a dominant genus across all geographical regions. For fungal communities, Ascomycota was the predominant phylum, while Nothophoma and Aureobasidium identified as the major genera. Diversity analyses revealed that both bacterial and fungal communities in the olive carposphere varied with cultivar, maturation stage, and geographical location. Among these factors, geographical location emerged as the most dominant driver, which implies that the environment and human activities play an important role in determining the carposphere microbiome. These findings enhance our understanding of the microbial diversity in olive carposphere, also provide valuable species information for the future use of microbial technology to modulate the fruit quality and prevent and control biological diseases.