Use of Bacillus velezensis JNS-1 from vermicompost against strawberry root rot

Lili Jiang ¹ Haohao Yan ² Yingzi Yin ¹ Ran Dong ¹ Chong Wu ^1*

• ¹ Shandong Institute of Pomology, Taian, China
• ² Shandong Agricultural University, Taian, Shandong Province, China

China has the largest strawberry global cultivation area. This study adopted an experimental method to explore the effect of adding vermicompost on the yield and quality of strawberries, as well as the influence of microbial community composition and activity in soilless cultivation systems. The addition of vermicompost significantly increased the activity of three soil enzymes: cellulase, urease, and acid phosphatase. In addition, it significantly increased the nitrogen content of strawberry-planted substrate-including through NO3-N, alkaline-N contents and organic matter-as well as the available K and cation exchange capacity. However, it had no significant effect on the available-P content of the substrate. Application of vermicompost effectively improved strawberry plant growth by transforming microbial diversity and increasing the level of beneficial microbial transcription. Application of vermicompost transformed the microbial diversity of the substrate. The average plant yield of the first crop fruit in the treatment including vermicompost was significantly higher than that in the control. Then, a biocontrol strain JNS-1 was isolated and identified as Bacillus velezensis from the vermicompost. We found that JNS-1 had a good direct inhibitory effect against the mycelial growth of Fusarium oxysporum and Neopestalotipsis sp. The strain JNS-1 as Bacillus velezensis according to its morphological and the 16S rRNA gene sequences. In greenhouse pot experiments and field trials, Bacillus velezensis JNS-1 can be effective in controlling strawberry root rot. The study focused on using B. velezensis JNS-1 to enhance the health and quality of strawberry, and provides a theoretical basis for the use of B. velezensis JNS-1 in strawberry fields.