The Identification and Development of Sunflower Germplasm with Resistance to Alternaria Blight

Abstract

The purpose of this study was to develop a system for identifying sunflower germplasm with resistance to Alternaria blight, which is caused by the necrotrophic fungus, 'Alternaria helianthi'. Field and greenhouse screening procedures were studied, so that a complementary system could be developed. Components of resistance measured in the greenhouse were tested for their correlation' with epidemic parameters obtained from field experiments. The following procedures are recommended to screen sunflower lines for their resistance to Alternaria blight under greenhouse conditions. The first or second pair of leaves of seedling plants at the V8 growth stage were inoculated using inoculum grown on sunflower leaf extract agar for 5-10 days. Approximately 30 spores were applied to each leaf. Inoculated plants were misted and subjected to a dew period of 48h inside a sealed plastic tent.