Genetic diversity, population structure and host resistance to phytophthora fruit rot in the solanaceae.

摘要

Production of eggplant (Solanum melongena) and pepper (Capsicum annuum), the third and fourth most important solanaceous crops worldwide, are limited by diseases caused by the oomycete pathogen Phytophthora capsici Leonian. In peppers, fruit rot resistance 3 and 5 days post inoculation (dpi) was mapped in an F6 recombinant inbred line population between a resistant, landrace Serrano and susceptible, cultivated Jalapeño. Isolate-specific interactions were evident and 10 quantitative trait loci were identified in the population with low to moderate effects. Diverse collections of eggplants (99) and peppers (160) were evaluated for genetic diversity, population structure, and fruit rot resistance to two isolates of P. capsici. In the eggplant and pepper collections, four genetic clusters were detected by Bayesian analysis. Resistance to one or both isolates was found for at least one accession in both collections. In the eggplant collection, population structure was detected when individuals were grouped by the following predefined categories: disease resistance, country of origin, continent of origin, and fruit shape. In the pepper collection, population structure was detected when individuals were grouped by disease resistance, country of origin, and continent of origin. These results provide a baseline for future work utilizing global pepper and eggplant resources, and developing Phytophthora fruit rot resistant cultivars.