Screening of Tomato (Lycopersicum esculentum L.) Varieties Resistant to Anthracnose Caused by Colletotrichum coccodes

Abstract

Anthracnose caused by Colletotrichum coccodes is one of the major disease problems in tomato (Lycopersicum esculentum) cultivation in Sri Lanka. Currendy fungicides are used to control this disease at an alarming scale. However, the use of resistant varieties is feasible, economical, and a reliable method to control the disease. There are about eighteen tomato cultivars available in Sri Lanka, which show differential disease response to this pathogen. Therefore, the current study was focused on developing a method in vitro to identify the resistant varieties of tomato to this disease. Studies were undertaken to find whether there was a relationship between varietal resistance/susceptibility and influence of conidia differentiation by leaf exudates of different tomato varieties. Stimulatory compounds which are responsible for conidia differentiation into appressoria were found in leaf exudates of all tested varieties of tomato. Percentage of conidia germination and appressoria formation in leaf exudates of varieties showed significant correlation