Management of postharvest green mold decay in common mandarin and Indian gooseberry with Bacillus licheniformis SR-14

Abstract

Common mandarin and Indian gooseberry are extremely important fruits and used in several countries for their medicinal properties. Bacillus licheniformis SR-14 strain was tested in vitro for their antagonistic properties against Penicillium digitatum, the causal agent of postharvest green mold decay in common mandarin and Indian gooseberry. In dual culture bioassay as circular and semicircular patterns, the isolate quantitatively inhibits the growth of the pathogen by more than 72 and 57 %, respectively. In vitro plate assay detected that the strain produces hydrolytic enzymes like protease, chitinase and volatile compound. Treatment with the antagonist also resulted in the induction of defense enzymes like, phenylalanine ammonia lyase, β-1, 3-glucanase and higher phenol accumulation compared to control. In vivo application of the antagonist revealed that the maximum mean disease index reached to 1.16 and 1.41 in Indian gooseberry and mandarin, which showed around 65 and 63 % reduction in disease severity, respectively when compared to control. These experiments suggest that the strain could be considered as a promising mean for the control of mandarin and Indian gooseberry postharvest green mold decay and its use may be an effective method to improve the integrated disease management strategy.