Evaluating the Resistance of Tomato Cultivars to Algerian <i>Phytophthora infestans</i> Genotypes under Controlled Trial

Abstract

Late blight is a destructive disease of solanaceous crops such as tomato (Solanum lycopersicum L.), caused by the Oomycete Phytophthora infestans (Mont.) de Bary. Late blight is generally controlled by fungicide applications, which quickly become ineffective due to the appearance of new P. infestans genotypes that can overcome the resistance of improved tomato cultivars and cause total production losses. The aim of this study is to assess the resistance level of tomato cultivars under controlled conditions and inoculations were carried out on detached leaflets (cvs. Trakia, Saint Pierre and Marmande) using inoculums of the major P. infestans clonal lineages found in Algeria such as EU_13_A2 (n = 1), EU_23_A1 (n = 2) and EU_2_A1 (n = 1) (three replicates of each isolate). This investigation showed that the choice of resistant cultivars can help control late blight and provide economic and environmental advantages by reducing the use of inputs.

Keywords

• resistance
• late blight
• <i>Phytophthora infestans</i>
• tomato