Location: Crop Improvement and Protection ResearchTitle: Screening of wild and cultivated Capsicum germplasm reveals new sources of Verticillium wilt resistance Author
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2015
Publication Date: 4/27/2015
Citation: Gurung, S., Short, D.P., Hu, X., Sandoya, G., Hayes, R.J., Subbarao, K.V. 2015. Screening of wild and cultivated Capsicum germplasm reveals new sources of Verticillium wilt resistance. Plant Disease. doi: 10.1094/PDIS-01-15-0113-RE. Interpretive Summary: Verticillium wilt is a destructive disease of pepper caused by the soil dwelling fungus Verticillium dahliae. This disease attacks many important crop and growing resistant varieties is the most sustainable method to control the disease. However, most commercial pepper varieties lack resistance to Verticillium wilt. We tested 397 unique strains, also called accessions, of wild and cultivated pepper from the National Plant Germplasm System of the USDA with two strains of Verticillium wilt in hopes of identifying resistant plants. In total, we identified eight accessions of pepper with resistance to both Verticillium wilt strains. Two of the accessions are Capsicum annuum, which is the most widely grown pepper species. These two accessions were determined in separate research to be resistant to a different disease caused by another soil dwelling microbe named Phytophthora capsici. These sources of multiple disease resistant peppers will be useful for breeding improved pepper varieties.
Technical Abstract: Verticillium wilt caused by Verticillium dahliae is an important soilborne disease of pepper (Capsicum species) worldwide. Most commercial pepper cultivars lack resistance to this pathogen. Our objective was to identify resistance to multiple V. dahliae isolates in wild and cultivated Capsicum accessions from the core collection of the National Plant Germplasm System of the USDA. Screening of 397 Capsicum accessions against two V. dahliae isolates (Vdca59, VdCf45) was performed in a greenhouse. Seventy-eight accessions selected from this screen were further evaluated in a follow-up experiment. In total, 21 (26.92%) and 13 (16.66%) Capsicum accessions tested were resistant to isolates VdCa59 and VdCf45, respectively. Eight accessions (Grif 9073, PI 281396, PI 289397, PI 438666, PI 439292, PI 439297, PI 555616, and PI 594125) were resistant to both V. dahliae isolates. On the basis of Germplasm Resources Information Network data, two of the Capsicum annuum accessions Grif 9073 and PI 439297 were also resistant to Phytophthora capsici. These sources of multiple disease resistance will be useful to pepper breeding programs.