Inhibition of Phytophthora species, agents of cocoa black pod disease, by secondary metabolites of Trichoderma species.

Environ Sci Pollut Res Int. 2017 Sep 30. doi: 10.1007/s11356-017-0283-9. [Epub ahead of print] Pakora GA1,2, Mpika J3, Kone D4, Ducamp M5, Kebe I6, Nay B1, Buisson D7. Author information 1 Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique (CNRS UMR 7245), 57 rue Buffon, CP54, 75005, Paris, France. 2 Département de Biosciences, Laboratoire Pharmacodynamie Biochimique, Université Felix Houphouët-Boigny, BP 582, Abidjan, 22, Côte d'Ivoire. 3 Station de Recherche de Bimbresso, CNRA, 01 BP 1536, Abidjan, 01, Côte d'Ivoire. 4 Laboratoire de Physiologie Végétale, Université de Cocody Abidjan, BP V34, Abidjan, Côte d'Ivoire. 5 UMR BGPI-CIRAD, TA A 54/K, Campus International de Baillarguet, 34398, Montpellier Cedex 5, France. 6 Laboratoire de Phytopathologie, CNRA, BP 808, Divo, Côte d'Ivoire. 7 Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique (CNRS UMR 7245), 57 rue Buffon, CP54, 75005, Paris, France. buisson@mnhn.fr. Abstract Cocoa production is affected by the black pod disease caused by several Phytophthora species that bring, about each year, an estimated loss of 44% of world production. Chemical control remains expensive and poses an enormous risk of poisoning for the users and the environment. Biocontrol by using antagonistic microorganisms has become an alternative to the integrated control strategy against this disease. Trichoderma viride T7, T. harzanium T40, and T. asperellum T54, which showed in vivo and in vitro antagonistic activity against P. palmivora, were cultured and mycelia extracted. Inhibition activity of crude extracts was determined, and then organic compounds were isolated and characterized. The in vitro effect of each compound on the conidia germination and mycelia growth of four P. palmivora, two P. megakaria, and one P. capsici was evaluated. T. viride that displayed best activities produced two active metabolites, viridin and gliovirin, against P. palmivora and P. megakaria strains. However, no activity against P. capsici was observed. Besides being active separately, these two compounds have a synergistic effect for both inhibitions, mycelia growth and conidia germination. These results provide the basis for the development of a low-impact pesticide based on a mixture of viridin and gliovirine. KEYWORDS: Cacao; Gliovirin; Phytophthora; Synergistic effect; Trichoderma virens; Viridin PMID: 28965291 DOI: 10.1007/s11356-017-0283-9