Inhibition Effect Of Postharvest Pathogens Fungi Of Fruit By Aureobasidin A

Aureobasidin A (AbA), an antifungal cyclic depsipeptide produced by Aureobasidium pullulans R106, is an effective antibiotic against a wide range of fungi and protozoa.Here we report the inhibitory effects of AbA on spore germination, germ tuber elongation and hyphal growth of five pathogenic fungi including Penicillium digitatum, P. italicum, P. expansum, Botrytis cinerea and Monilinia fructicola, which are major pathogens causing postharvest diseases of a variety of fruits. AbA inhibited five pathogenic fungi by reducing conidial germination rates, delaying conidial germination initiation, restricting elongation of germ tuber and mycelium, as well as inducing abnormal alternations of morphology of germ tubes and hyphae of these fungi. the stage of germling was more sensitive than the stages of hyphal extension. The sensitivity of these fungi to AbA was pathogen species-dependent. P. digitatum was the most sensitive and M. fructicola the least.The experiment which fungicidal infection of fruit was caused by P. digitatum and B. cinerea, shows that AbA was more effective than Imazalil(An effective pesticide in prevention and treatment citrus green mold) in citrus green mold and shows that AbA could reduce the strawberry gray mold incidence and severity. By observed by transmission electron microscope, we consider that AbA make cell membrane disruption and make cell plasma to leak, to disrupt or kill the cell.