TITLE:
Biological Activity of Syzygium aromaticum and Ravensara aromatica Essential Oils from Madagascar and Their Possible Use against Postharvest Mango Anthracnose
AUTHORS:
Soloniony Navalonamanitra Andrianjafinandrasana, Marc Chillet, Isabelle Ratsimiala Ramonta, Jean-Michel Leong Pock Tsy, Jerôme Minier, Pascal Danthu
KEYWORDS:
Biological Activity, Syzygium aromaticum, Ravensara aromatic, Fungitoxicity, Anthracnose, Essential Oils
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.11,
November
13,
2020
ABSTRACT: The fungitoxicity of five Malagasy essential oils
(Eos) against Colletotrichum asianum was assessed in terms of conidial
germination and mycelial growth. Their effect on defense-related compounds
content, physicochemical properties and anthracnose lesions in mango fruits was also determined. Four of the
tested Eos were from Ravensara aromatica leaves, and the last Eo was
extracted from clove leaves. Their chemical compositions were then determined
through GC-MS analysis and the active compound of the most fungitoxic Eo was
determined by testing the toxicity of its major component to C. asianums spore germination, mycelial growth and its ability to inhibit anthracnose
development on mango fruits. The R. aromatica Eos tested were fungistatic to C. asianum, whereas clove Eo was fungitoxic and the 4 chemotypes of R. aromatica Eo exhibited variable inhibiting capabilities: 1) all tested doses of all Eos (112.5 and 225 μL/L of air) were effective against C. asianum mycelial
growth (10% - 100%
inhibition) but doses of 225 μL/L
were more inhibitory than those of 112.5 μL/L, 2) Conidial germination was more resistant to Eos toxicity since only 225 μL/L of methyl eugenol chemotype of R. aromatica Eo, all tested doses of
the sabinene chemotype
of R. aromatica Eo and clove Eo were found
inhibitory toward conidial germination of C. asianum. 30 μL/L of sprayed clove Eoweretested on inoculated
mangoes and were found to be effective against anthracnose development without affecting the resorcinol content in mango peel and the
physicochemical properties of mango pulp. Tests on the major components of
clove Eo showed fungitoxic activities against mycelial growth and conidial
germination of C. asianum similar to those of clove
Eo.