Effect of Water-Soluble Fraction of Petroleum Hydrocarbon on the Growth and Sporulation of Botryodiplodia theobromae (Pat.)

摘要

The control of fungal pathogens of economic crops in soil is crucial to sustainable food production and distribution. In this study, the effect of aqueous fractions of petroleum hydrocarbons was investigated on the growth and sporulation of Botryodiplodia theobromae (Pat.), a common fungal pathogen isolated from rotten cassava tubers. The fungal isolates were subjected to graded concentrations of the water-soluble fraction (WSF) of crude oil and monitored for their effects on the mycelial growth and spore germination using standard mycological media and techniques. Results revealed that the biological effects of the chemical fraction were concentration dependent and significant at P = 0.01 and 0.05 when compared with the controls. After 5 h, the least inhibitory effect against the spore germination was observed by the 1 mL WSF concentration with 87% spore germination. The effects were significantly different (P<0.01) at WSF concentrations of 7.0-9.0 mg/mL with percentage germination values of 44%, 46% and 29% respectively. The mycelial growths were also significantly reduced with the highest inhibition being 73% at 9.0 mg/mL. The mycelial dry weight remained significantly unchanged (P>0.05) at higher concentrations. Findings from this study suggest that aqueous soluble fractions of petroleum hydrocarbons can significantly inhibit the spores and mycelium growth of B. theobromae (Pat.). Thus, they could be exploited as template for biosynthesis of potential fungicide against the test phytopathogens.