Biological Control of Ustilaginoidea virens Using Chelerythrine Suspension

Abstract

Background: High efficiency, low toxicity, and environmentally safe pesticides are increasingly being sought and developed to ensure sustainable development and high-yield agricultural production. Chelerythrine has strong inhibitory effects against the mycelial growth of crop pathogens such as Fusarium oxysporum, Anthrax, and grey mold. Our previous studies have shown that chelerythrine inhibits fungus spore germination by up to 86.7% and induces the apoptosis of Ustilaginoidea virens cells. The application of chelerythrine as a green biological pesticide would not only enhance agricultural production but also enhance ecological protection. Materials and Methods: The formulation of a chelerythrine suspension concentrate was selected. According to the ratio of experimental design requirements to preparation sample, six groups were set up in the field assay; the first spraying was performed approximately 7 days before the rice rupture period, and the second spraying was performed after 10 days. The control effect was investigated at the milk-ripe stage. The present study preliminarily investigates the safety of chelerythrine as a pesticide using the oral acute toxicity test for mice. Results: In the present study, the effect of chelerythrine as the main ingredient in suspension concentrate formulations and its field effect on rice false smut (RFS) was investigated. The pesticide in the suspending agent was sprayed twice and had superior effects with regard to the prevention and control of RFS in the field. The control effect was 95.88% at an application rate of 192 mL/ha, with low residue, environmentally safe, and low resistance characteristics. An acute toxicity test following intragastric administration in mice showed that the LD50 of chelerythrine suspension was 1580 mg·kg−1, which was much lower than those of other low-toxicity commercial pesticides. Conclusion: Chelerythrine suspension was a low-toxicity agent and exhibited the characteristics of an environmentally friendly plant pesticide. The application of chelerythrine suspension could facilitate the achievement of the goal of pesticide reduction efficiency.