Abstract:

The root microbiota is susceptible to the influence of the plant growth stages and genotypes. To explore the differences in the rhizosphere bacterial flora of flue-cured tobacco varieties and their interactions, the new tobacco variety Zhongchuan 208 and CV87 were used as test materials in the present study. By utilizing 16S rRNA sequencing, sequences of the rhizosphere bacterial flora were obtained. Through methods such as diversity and compositional analysis, a detailed comparison of the rhizosphere bacterial flora of two flue-cured tobacco varieties at various growth stages was conducted. It was revealed that genotypes and growth stages affected the structure of rhizosphere bacterial communities and the relationships between bacteria. For Zhongchuan 208, the highest diversity was observed during the early blooming stage, while for CV87, the highest diversity was found during the maturity stage. There were 435 and 282 edges (correlation data) between species in the rhizosphere bacterial flora of Zhongchuan 208 and CV87, respectively, indicating that the interactions within rhizosphere bacterial flora of Zhongchuan 208 were richer and more complex than those of CV87. During the rosette and vigorous growth stages, the genus Azoarcus in the rhizosphere of Zhongchuan 208 was relatively abundant, which may help the plant obtain nitrogen through nitrogen fixation, thereby promoting the plant growth. In the rhizosphere of CV87, Ramlibacter maintained a relatively high abundance during the rosette and vigorous growth stages, which may participate in the activation of the antioxidant system of plant to enhance the resistance to diseases and other processes. The findings provided both data and theoretical basis for a deeper understanding of the compositional patterns and the interaction mechanisms of the rhizosphere microbiome of flue-cured tobacco.

Key words: flue-cured tobacco, rhizosphere microbiome, diversity analysis, taxonomic composition