Scientific publications
Marie Elvia Akong
Patrice Zemko Ngatsi
William Norbert Kuaté Tueguem
Thierry Atindo Songwe
Hubert Boli
Claire Stéphane Tsogo
Journal of Tropical Biodiversity and Biotechnology
Cercospora malayensis induced leaf spot is a dangerous okra disease that reduces crop yields. The aim of this study is to use leaf extract from Crinum zeylanicum to regulate the growth of Cercospora malayensis in vitro. The pathogen was isolated from okra leaves from the Meyomessala and Akonolinga localities that had typical disease symptoms. Phytochemical screening and GC-MS analysis of C. zeylanicum leaf extracts were carried out. The mycelial growth and germination of C. malayensis isolates 1 and 2 were evaluated with concentrations of 15, 30, 60, and 120 μL mL-1, fungicide (3.33 g L-1), and control. Minimum inhibition concentrations (MIC50 and MIC90) were evaluated. The results showed the presence of alkaloids, phenols, terpenoids and sterols in the leaf extracts. In acetone (AcE), methanol (ME) and aqueous (AqE) extracts, 32; 39 and 10 chemical compounds, respectively were found by GC-MS analysis. The most prevalent biochemically active compounds were n-Hexadecanoic acid (35.04 %), Cis-Vaccenic acid (31.76 %), Quinoline-7-carboxylic acid, 2-phenyl-, methyl ester (26.63 %), 9,12-Octadecadienoic acid (Z,Z)- methyl ester (16.89 %) and 9,12-Octadecadienoic acid (Z,Z) (10.83 %). AqE, AcE and ME extracts at 120 μL mL-1 inhibited 100 % of mycelial growth and conidial germination of isolates 1 and 2 compared to the control. The lowest MICs (MIC50 and MIC90) were 6.79 and 10.98 μL mL-1 for isolate 1 and 7.48 and 11.22 μL mL-1 for isolate 2, respectively. C. zeylanicum it is possible to use extracts for their volatile biochemical substances in a C. malayensis control program.
