A GENETICALLY-CONTROLLED NECROTIC SPOTTING OF CORN LEAVES

Abstract

Corn plants of several cultivars were found in the field in 1972 and 1973 with a prominent pattern of small whitish necrotic spots on their leaves. No organisms could be isolated from the lesions. They start as water-soaked spots, and certain environmental conditions favor their appearance. The condition was shown to be seed-transmitted. Self-pollinating affected plants and cross-pollinations between affected and healthy plants resulted in genetically significant ratios of affected and healthy plants which supported the hypothesis that the condition is controlled by a single dominant gene. It very closely resembles a genetically-controlled necrotic leaf spotting produced by Neuffer and Calvert with a mutagen acting on pollen grains.