Control Effects of Different Bacillus Strains Against Postharvest Alternaria alternata of Super-early Maturing Peach and Analysis of Volatile Organic Compounds of Its Fermented Broth

In order to investigate the control effects of fermented broth of Bacillus strains and volatile organic compounds against postharvest Alternaria alternata of the"JinLiuZaoHong"super-early maturing peach, the injury inoculation method, post-harvest soaking method and plate-to-plate method were studied. The antibacterial activity and the effect of three Bacillus strains HB-2, B1 and X on postharvest quality of super-early maturing peach, and the antibacterial activity of volatile organic compounds of fermented broth was analyzed by the two-sealed-base-plates method and headspace solidphase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) method. The results showed that fermented broth of three Bacillus strains could significantly inhibit the colonization growth of Alternaria alternata (p<0.05) compared with the control group, and they also significantly delayed the decreasing of vitamin C contents, titratable acid contents and firmness and maintained quality, with the order of HB-2>X>B1.In addition, the volatile organic compound sproduced by three Bacillus strains fermented broth had significant inhibitory effect on the expansion of Alternaria alternata colonies with the inhibitory rate reached above 50%, and 28, 31 and 30 kinds of compounds were identified in HB-2, B1 and X, respectively, such as alcohols, esters, ketones, acids, phenols, alkanes and so on. Bacillus HB-2, B1 and X would have potential application for the biological control of postharvest diseases of super-early maturing peach.