Changes in bacterial diversity and community structure in rhizosphere soil of lavender with different continuous cropping years

Lavender (Lavandula angustifolia Mill) is a plant of the genus Lavender in the family Lamiaceae, which has a wide range of commercial value. Understanding the impact of continuous cropping years on bacterial diversity and community structure changes in the rhizosphere soil of lavender is of great significance for the growth status, yield, and further application of lavender. Collect soil samples from Huocheng County, Ili, Xinjiang, with planting years of 1 year, 3 years, and 5 years, as well as 3 groups of soil samples without planting lavender. Perform high-throughput Illumina sequencing on 16S rDNA sequences. Analyze the sequencing results, compare the bacterial diversity and community distribution patterns of each sample group, and their correlation with planting years. Alpha diversity analysis shows that with the increase of continuous cropping years, both Shannon index and Chao1 index first decrease and then increase. A total of 48 phyla, 53 classes, 127 orders, 253 families, and 562 genera were detected in the soil for planting lavender. At the phylum level, Acidobacteria, Proteobacteria, and Actinobacteria are dominant phyla, and the relative abundance of Acidobacteria and Actinobacteria decreases and then increases with age, while Proteobacteria increases and then decreases. At the genus level, the dominant bacterial genera are an unclassified genus in the phylum Acidobacteria, Sphingomonas, and Stenotrophobacter. The relative abundance of Sphingomonas first decreases and then increases, while the unclassified genus and Acidobacter in the phylum Acidobacteria first increase and then decrease. Beta diversity also showed significant changes compared to unplanted soil, with the first and fifth years being similar, both showing significant differences from the third year or related to changes in soil pH.These results indicate that continuous cultivation of lavender resulted in changes in the structure and diversity of bacterial communities in the rhizosphere soil. This article provides a theoretical basis for the growth and yield increase of lavender, and a reference for the scientific management of lavender soil.