ANTAGONISM OF Bacillus licheniformis M2–7 AGAINST PHYTOPATHOGEN FUNGI OF Mangifera indica L.

Abstract

The biological control using organisms that inhibit growth or the appearance of pests or diseases has proven to be a successful alternative for mango disease control. In this work, in vitro analyses were carried out with Bacillus licheniformis M2–7 and B. licheniformis LYA12 strain derived from M2–7 against the phytopathogenic fungi Aspergillus oryzae, Colletotrichum sp., and Aspergillus niger. Besides, the effect of bacteria on the micellar structure of phytopathogenic fungi was observed and evaluated through real-time PCR, the expression of two main metacaspases (casA and casB) that triggers the process of programmed cell death in fungi. The results obtained showed that both bacterial species inhibited by 45, 40, and 35 % the fungal growth of Aspergillus oryzae , Colletotrichum sp., and Aspergillus niger, respectively. The bacteria presence affected the mycelial appearance of the fungi because they presented fragmentation of the hyphae with intracellular inclusion bodies, swellings, malformations and scarce growth of the hyphae. The gene expression results conclude that the LYA12 and M2-7 strains against A. oryzae and A. niger have a fungicidal effect; therefore, the bacterial strains could be used in disease control in mango.