The influence of extracts from senescent corn leaves on sexual reproduction in Cochliobolus carbonum

Abstract

The biochemical requirements for the formation of perithecia, asci, and ascospores in Cochliobolus carbonum are present in senescent corn leaves. A chloroform–methanol extract from senescent corn leaves was found to support perithecial formation. Efforts were made to identify the compounds responsible for the observed activity.The qualitative and quantitative effects of several concentrations of the crude chloroform–methanol extract and of some fractions separated therefrom on the sexual process were studied. Sterol and watersoluble fractions stimulated perithecial formation. Each was active when applied alone, but stimulation was greater when the fractions were combined. Fatty acid fractions did not increase the number of perithecia formed. Neither the crude extract nor any of the components tested stimulated ascus and ascospore formation.It is suggested that the mode of action of perithecial stimulating chemicals extracted from senescent corn leaves is nutritional. The rationale for this belief is discussed.