Antifungal activity of 2-decanone against Monilinia fructicola and its application in combination with boscalid in mitigating brown rot disease in peach fruit

Peach fruit is highly susceptible to Monilinia fructicola ( M. fructicola ), a pathogen that causes significant postharvest losses. Enhancing the efficacy and reducing the dosage of chemical fungicides are critical for controlling brown rot caused by M. fructicola . Natural volatile organic compounds (VOCs) have been proposed as a selective method for managing postharvest pathogen infection. Among these, 2-decanone, a natural volatile produced by fungi and insects, has demonstrated potential in inhibiting pathogen growth. In this study, 60 μL/L 2-decanone effectively inhibited the growth of M. fructicola mycelia. It also reduced spore germination and appressorium formation by downregulating the expression of MfBmp1 and MfPls1 , respectively. In addition, 2-decanone induced spore apoptosis by increasing reactive oxygen species (ROS) accumulation and exacerbating mitochondrial damage. When applied to peach fruit, 2-decanone fumigation significantly reduced disease incidence and lesion diameter compared to the control group, without adversely affecting fruit quality during storage. Furthermore, we observed that 2-decanone exhibited synergistic effects when combined with boscalid, effectively inhibiting the growth of M. fructicola . Applying boscalid 15 days before harvest and fumigating with 2-decanone postharvest provided similar brown rot suppression as boscalid alone but used only one-tenth the amount of fungicide. Overall, 2-decanone fumigation presents an effective strategy for controlling postharvest brown rot disease in peaches, and its combined use with boscalid introduces a promising approach for enhancing postharvest peach fruit preservation.