Resistance to Phytophthora Blight of Pepper

Phytophthora capsici causes crown, root, and fruit rot as well as foliar lesions in peppers. We conducted field trials in 2015 and 2016 to evaluate 32 commercial and experimental pepper cultivars against a mixed-isolate inoculum in North Carolina. Cultivars Martha-R and Meeting were classified as highly resistant to P. capsici.

Greenhouse experiments were also conducted to determine the response of 48 pepper cultivars when inoculated individually with two isolates from North Carolina and an isolate from Michigan. Phytophthora capsici isolates exhibited different levels of virulence in pepper cultivars screened for resistance. Landraces CM334 and Fidel as well as the cultivars Martha-R, Meeting, and Intruder were categorized as highly resistant or resistant to the three isolates tested.

Today, host resistance remains a promising management strategy to control P. capsici in pepper, and our study highlighted the importance of accounting for pathogen diversity when screening for resistance.