Control of Southern Root-knot Nematodes on Tomato and Regulation of Soil Bacterial Community by Biofumigation with Zanthoxylum bungeanum Seed

Biofumigation is an environmentally friendly strategy used to control nematodes and plant diseases. The volatile oil of Zanthoxylum bungeanum has high insecticidal and antibacterial activity. However, it is not known if the seed of Z . bungeanum is a suitable material for biofumigation to control southern root-knot nematodes (SRKN) on tomato, and how it may regulate the soil bacterial community structure. We used pot experiments in the greenhouse to determine the effects of Z. bungeanum seeds on SRKN, plant growth parameters, soil physicochemical and microbial characteristics. A total of 26 volatile components, including nematicidally active substances, were identified from Z. bungeanum seeds. Z. bungeanum seed biofumigation significantly reduced the SRKN population by 88.89% and 81.55% on the 50th and 100th day after transplanting, respectively. Compared to the control, the total soluble sugar, soluble solids, soluble protein, titratable acid, root activity and the fruit yield per tomato plant increased significantly. The content of soil alkali-hydrolyzed nitrogen, available potassium and the soil enzyme activities were also significantly increased. The soil bacterial diversity and the co-occurrence network complexity were increased by Z. bungeanum seed biofumigation. Relatively more keystone OTUs in biofumigation soil had potential plant growth-promoting capabilities. The function of Z. bungeanum seed increasing tomato production in SRKN-infected soil depends on directly killing SRKN and improving soil properties. These results indicate that Z. bungeanum seed can be used as both a nematicide and a high quality organic fertilizer in tomato production.