In Vitro Formation of Sexual Stage of Thielaviopsis paradoxa from Sugarcane in Puerto Rico

Abstract

Two strains of Thielaviopsis paradoxa, one light and one dark, were isolated from diseased cuttings of sugarcane in Puerto Rico. Perithecia were produced when the dark strain was crossed with the light strain in potato dextrose agar medium at 24° to 28° C. The perithecia obtained are characteristic of Ceratocystis paradoxa (horn-like appendages on the base of the perithecia and long, pointed ostiolar hyphae). Ascospore isolations consistently resulted in the recovery of typical T. paradoxa culture. No perithecia were produced when cultures of the same isolates were crossed. This constitutes the first report on formation of the sexual stage of T. paradoxa from sugarcane in vitro