Genetic Resources of Capsicum

Abstract

Peppers belong to the genus Capsicum of the Solanaceae family and represent plants producing fruits with variable degrees of pungency (highly pungent to nonpungent). Peppers are native to the tropical and temperate Americas. Capsaicinoids (the secondary metabolite responsible for pungency) are uniquely produced in the genus Capsicum, which consists of approximately 35 species. There are five widely domesticated and cultivated species (C. annuum, C. frutescens, C. chinense, C. baccatum, and C. pubescens). The wild progenitor C. annuum var. glabriusculum chili pepper (chiltepin) typically has small-round, erect, highly pungent, deciduous, and soft-fleshed fruits. Capsicum genetic resources have been successfully used in modern plant breeding programs to develop and commercialize sweet and hot pepper cultivars with diverse market types. Primarily these include breeding for abiotic and biotic stresses and speciality traits for industrial extraction. However, unlike the closely related tomato, the use of wild Capsicum germplasm in pepper improvement programs is extremely limited. There are currently no wild Capsicum species listed as vulnerable, threatened, or endangered by the US Endangered Species Act. However, this is likely inaccurate as tropical rainforest is being used for agriculture and other forms of habitat modification, resulting in the natural habitat of wild Capsicum germplasm being lost. The genetic resources against biotic stresses have the potential to be depleted, due to the rapid evolution of new pathotypes. Therefore, the search for new resistance source against specific pathogens and their deployment in commercial cultivars is a continuous process. Ensuring alignment of national and international policy regulations is needed so that unique Capsicum genetic resources are able to be collected, conserved, and distributed, which is critical to the overall success of ex situ conservation.