Evaluation of pepper (Capsicum annuum L.) varieties to several methods of inoculation with Verticillium dahliae Kleb. in different conditions

Katya Vasileva and Velichka Todorova

Abstract: Verticillium wilt caused by Verticillium dahliae Kleb. of pepper (Capsicum species) is an important soilborn disease. Surveys of ten Bulgarian commercial pepper (Capsicum annuum L.) varieties were conducted to gain information on the incidence of diseases. Several methods of inoculation with the pathogen of Verticillium dahliae Kleb. have been used to test the resistance of the varieties in different conditions. Field and greenhouse diagnostics along with laboratory assays of wilted plants revealed that the wilting was caused by Verticillium dahliae Kleb. In the Verticillium field with additional infection at second observation Kurtovska kapia 1 (23.12%) was least affected. At first monitoring of Verticillium field without additional infection it was found that the varieties Kapia UV, Kaloyan, Kurtovska kapia 1, Ivaylovska kapia, Sivria 600 and Stryama did not attack by the pathogen but at second – only variety Kaloyan was non infected. Under greenhouse conditions least affected varieties in both observations are Kurtovska kapia 1 (17.35%–19.64%), Zlaten medal 7 (10.00%–10.00%), Milkana F1 (10.31%–27.11%). Explicably, an infestation index is comparatively lower in the conventional field with natural background and Verticillium field than other variants with artificial inoculation. In all investigated variants of testing the varieties Kurtovska kapia 1, Milkana F1 and Stryama were with the highest level of resistance to Vericillium dahliae Kleb. In pathogenicity tests, isolates of V. dahliae Kleb. caused symptoms in inoculated pepper identical to those in field and greenhouse-grown pepper plants. Results indicate that diseases, posing the most serious challenge to pepper cultivars in Bulgaria. The best hope for control of Verticillium wilt in most crops lies in the development of new wilt-resistant varieties, or the incorporation of resistance into commercial varieties.

Keywords: pepper; resistance; Verticillium dahliae Kleb.

Date published: 2020-04-30