Colonization of Bacillus licheliformis Wl0 on the surface of apple and orange fruit

LING Zheng; JI Zhao-lin; ZHANG Ji-bing; XU Jing-you; CHEN Xi-jun; TONG Yun-hui

Abstract：Bacillus licheniformis WlO was a novel antagonistic bacterium against plant pathogens.For better understanding its role in bioeontrol mechanisms the colonizing ability of WI0 on the surface of apple and orange fruit was studied in this pa-per.W10 isolate was marked with rifampicin and the marked bacteria were inoculated to the surface of fruit of apple and or-ange.The bacteria on the surface of the inoculated fruit were isolated by the culture medium with rifampicin at stated periods.The results showed that W10 could colonize on the surface of apple and organ fruit.The persistent time of colonization reached 15 d on the apple fruit while that was 30 d on the orange. The higher bacterial concentration (10~(10) cfu· mL~(-1)) applied,the more favorably colonized W10 on those fruit surface.The colonizing ability of WlO was the strongest at 15℃ ,muchmore than that of at 5℃ and 10 ℃.Moreover,higher relative humidity (RH 95% to 100%)in preservation period of fruit was favorable for W10 colonization,and more bacteria could be reclaimed on that condition.In comparison with inoculation of WIO only, pre-inoculation of pathogen bad a negative effect on colonization of W10.Above experiment results implied that W10 colonizing ability was affected by some factors,that higher bacterial concentration and suited temperature and higher relative humidity and pre-eolonization of pathogen were needed in order to promote the bacterial colonization on the fruit sur-face of apple and orange.