Biocontrol ability and action mechanism of dihydromaltophilin againstColletotrichum fructicolacausing anthracnose of pear fruit

BACKGROUND Anthracnose caused byColletotrichum fructicolais one of the most important diseases in pear fruit, resulting in huge economic losses. Public awareness of protecting the environment and food safety, together with pathogen resistance to many key fungicides have led to an urgent need to develop alternative strategies for controlling fruit diseases. Here, the antifungal activity of a natural product, dihydromaltophilin [heat-stable antifungal factor (HSAF)], againstC. fructicola in vitroandin vivowas investigated to determine its efficacy for anthracnose management. RESULTS HSAF exhibited pronounced antifungal activity againstin vitromycelial growth ofC. fructicola, with a half-inhibition concentration of 0.43 mg L-1. Hyphae treated with HSAF showed defects such as hyperbranching, swelling and depolarized growth. Conidia germination in the pathogen was inhibited by HSAF in a dose-dependent manner. In the presence of 4 mg L(-1)HSAF, conidia germination was significantly delayed, and germ tube growth was inhibited. HSAF at 8 mg L(-1)completely blocked conidia germination inC. fructicola. In addition, HSAF disrupted coordination of cytokinesis with growth and nuclear division, induced reactive oxygen species production in conidia, and damaged the integrity of the conidia cell wall. Moreover, anin vivotest confirmed that 50 mg L(-1)HSAF significantly reduced the development of anthracnose decay in pear fruit caused byC. fructicola. CONCLUSION HSAF was highly effective in reducing pear anthracnose caused byC. fructicolaand has great potential to become a new type of fruit preservative.

Automated summary

This study shows that HSAF has strong antifungal activity against pear anthracnose caused by C. fructicola, effectively reducing disease development. HSAF inhibits mycelial growth and conidia germination of the pathogen, demonstrating great potential as a new type of fruit preservative.