Effects of Genetic Relationships between Different Oaks (Quercus spp.) on Their Rhizosphere Bacterial Communities

There is a complex symbiotic relationship between plants and rhizosphere bacteria: the rhizosphere exudate of plants can affect the rhizosphere bacterial community. Abiotic factors such as soil properties and climatic characteristics can also affect plants and their rhizosphere bacteria. However, it is still unclear the effect of genotypes of different Quercus species on their rhizosphere bacteria. In this study, we explore the diversity and abundance of rhizosphere bacterial communities in five Quercus species: Quercus. Aliena (AS), Quercus. dentate [1], Quercus. Mongolica (MS), Quercus. Variabilis (VS) and Quercus. Wutaishanica [2]. We found that the rhizosphere bacterial alpha diversity indexs were significantly different, showing that AS had the highest bacterial alpha diversity and richness in the roots, while VS had the lowest bacterial alpha diversity and richness in the roots. Besides, we found the top two dominant phyla with obvious changes in relative abundance is Proteobacteria (28.7%-38.9%), Firmicutes (11.2%-23.9%). The genetic relationship between Q. Aliena and Q. dentate is relatively close, the relative abundance of rhizosphere bacteria (such as Proteobacteria and Bacteroidota) is similar to each other. Conversely, the relative abundance of rhizosphere bacteria (such as Bacteroidota and Acidobacteria) varies greatly due to the genetic relationship of Q. variabilis compared to the others relatively distant. Therefore, our results suggest that the diversity and relative abundance of rhizosphere bacteria is correlation with the genetic relationship among different Quercus species.