ABSTRACT Citrus fruits are subject to the postharvest disease of rotting due to fungal infections during storage, transportation and sales, resulting in a large economic loss. Biological antimicrobials are favoured as an environmentally friendly method with low safety risks. The endophytes of citrus were isolated and identified and found that Burkholderi sp. LG83 was a new type of biocontrol bacterium that had an obvious antifungal growth effect. In vivo biocontrol antagonism assays demonstrated that the cell‐free fermentation supernatant of Burkholderi sp. LG83 significantly inhibited the expansion of postharvest fungi. Specifically, 7 out of 10 and 8 out of 10 treated fruits were completely protected against Penicillium italicum and Penicillium digitatum infections, achieving disease inhibition rates of 70% and 80%, respectively. Statistical analysis via Fisher's Exact Test confirmed that the biocontrol efficacy of the endophytic supernatant was significantly superior to the negative control ( p < 0.05), exhibiting a disease management potential comparable to that of prochloraz, a widely applied commercial fungicide. The strong antifungal components of secondary metabolites include cinnamaldehyde, cinnamic acid, dodecanoic acid, and phenazine‐1‐carboxylic acid (PCA). These metabolites can damage the fungal structure, consume a significant amount of energy, and produce a large number of reactive oxygen species, thereby promoting the death of the fungus. LG83 is an effective biological control and has important application potential in the postharvest management of disease in citrus fruits.
Wu et al. (Fri,) studied this question.