Production of Volatile Organic Compounds of Fusarium oxysporum f. sp. lycopersici on Coinoculation with the Metabolites of Chaetomium globosum

Abstract

e present study focused on divulging the effect of 15 and 30 days old culture filtrates of Chaetomium globosum on the mycelial growth and toxin production of Fusarium oxysporum f. sp. lycopersici. The cell-free culture (CFC) filtrate of C. globosum was inoculated in the liquid medium of F. oxysporum f. sp. lycopersici. The results revealed that mycelial growth was reduced in the CFC filtrate of C. globosum inoculated medium compared to control (pathogen alone). The mycelial dry weight of the F. oxysporum f. sp. lycopersici was 0.864g in fifteen days old CFC filtrate followed by 30 days old CFC filtrate of C. globosum (1.374g) amended medium. Metabolites from the CFC filtrate and control were extracted separately using chloroform followed by ethyl acetate and the extract was subjected to GC-MS analysis. GC-MS analyses showed that methyl ester group was present in 15 days old culture filtrate condensate compared to 30 days old CFC. The compounds are methyl tetradecanoate, octadecanoic acid, methyl ester, and DL-Proline, 5-oxo-, methyl ester. Thirty days old culture filtrate condensate of C. globosum contained more phenol groups like phenol 2,4-bis (1,1-dimethylethyl) at 17.62 RT followed by diisooctyl phthalate, 17-pentatriacontene, cholestan-3-ol, 2-methylene-, (3a,5a) and bicycle [4.1.0]heptanes,-3-cyclopropyl,-7-hydroxymethyl,trans. Metabolites of F. o. f. sp. lycopersici were also characterized by GC-MS, which showed very few volatile compounds like methyl tetradecanone , oleic acid, eicosyl ester, methyl stearate, and bis(2-ethylhexyl)phthalate. These compounds were not detected in co-inoculation of 15 and 30 days old CFC filtrate of C. globosum and F. o. f. sp. lycopersici. The difference in the volatile profile may be due to the effect of the metabolites of C. globosum on F. o. f.sp. lycopersici.