Effect of host extract on growth and sporulation of Cercospora lactucae-sativae

Abstract

Cercospora lactucae-sativae is a slow growing hemibiotrophic fungus that proves difficult to isolate and sporulate on many growth media. The study focussed on the use of a simple isolation procedure for C. lactucae-sativae and examined the effect of host extract on growth and sporulation of C. lactucae-sativae on PDA and Water Agar. The mean colony diameter was significantly greater than that of the control treatment for WA + LE at 1%, 2% and 4% only, and for all of the LE concentrations on PDA. The mean conidial concentration was significantly different from the control treatment for all concentrations on WA at and above 2% LE, while on PDA there were no significant differences between any of the treatment including the control. PCR has confirmed that the leaf spot disease affecting lettuce cultivation in Trinidad is caused by C. lactucae-sativae.