In vitro Study of the Antifungal Activity of Essential Oils from Syzygium aromaticum, Eucalyptus globulus, Cymbopogon giganteus, and C. citratus against Strains of Lasiodiplodia theobromae and Pseudocercospora fijiensis in the Kisangani Region (DR Congo)
Asumani Kamusose Martin *
Laboratory of Microbiology and Phytopathology, Faculty of Natural Sciences and Biotechnology, University of Kisangani, DR Congo.
Akwakwa Hopla Gabriel
Laboratory of Microbiology and Phytopathology, Faculty of Natural Sciences and Biotechnology, University of Kisangani, DR Congo.
Osako Omelonga Louison
Department of Biology-Chemistry, Isangi Higher Pedagogical Institute, DR Congo.
Liyeye Jean-Pierre
General Reference Hospital, Makiso Kisangani, DR Congo.
Limba Kimwanga Mukwa KIBUKA
National Cocoa Research Program, National Institute for Agronomic Study and Research in Yangambi, DR Congo.
Kwembe Gonganape Jean-Trésor
Laboratory of Natural Product Chemistry, Faculty of Natural Sciences and Biotechnology, University of Kisangani, DR Congo.
Onautshu Odimba Didy
Laboratory of Microbiology and Phytopathology, Faculty of Natural Sciences and Biotechnology, University of Kisangani, DR Congo.
*Author to whom correspondence should be addressed.
Abstract
The aim of this study was to evaluate in vitro the antifungal activity of essential oils from Syzygium aromaticum, Eucalyptus globulus, Cymbopogon giganteus, and C. citratus against strains of Lasiodiplodia theobromae and Pseudocercospora fijiensis. The hydrodistillation technique was used to extract the essential oils. L. theobromae strains were isolated from mesocarp fragments collected from diseased cocoa plants, while P. fijiensis strains were obtained by the method of spore discharge onto Water Agar medium followed by transfer to Potato Dextrose Agar (PDA) medium. The method of mycelial growth inhibition on PDA solid medium in Petri dishes was applied to assess the sensitivity of the strains to the essential oils of the aromatic plants studied.
The results obtained show that all essential oils from the tested aromatic plants have remarkable inhibitory effects on the mycelial growth of the studied L. theobromae and P. fijiensis strains. However, no mycelial growth (0 mm in diameter) was observed during nearly three days of incubation.
Keywords: Antifungal, essential oil, Lasiodiplodia theobromae, Pseudocercospora fijiensis, Kisangani