AN ELECTROPHORETIC STUDY OF EVOLUTION IN CAPSICUM (SOLANACEAE).

Abstract

Most recent treatments of the peppers, genus Capsicum (Solanaceae), recognize four or five domesticated taxa and 20 or more wild species (Eshbaugh, 1980a). The distribution of the species is fairly well documented with the exception of the Brazilian taxa. The genus includes a number of wide ranging species as well as several narrow endemics, e.g., C. galapagoensis, C. cardenasii, etc. All taxa are at least facultative self-fertilizers with the exception of C. cardenasii. A survey of chromosome numbers indicates n = 12 or 13 (Pickersgill, 1977), suggesting two lines of evolution which may eventually require some realignment at the generic level. Changing concepts on evolution of the genus have led from the hypothesis of C. frutescens as the single wild progenitor of all the domesticates (Davenport, 1970; Ramalingam, 1972; Jett, 1973), to four or five distinct progenitors each giving rise to a domesticate (Heiser et al., 1971) and alternatively, to three independent lines of evolution leading to domesticated C. baccatum, C. pubescens, and a complex of C. annuum, C. chinense, and C. frutescens (Eshbaugh, 1980b). Various approaches to investigating and understanding evolution in the genus have included comparative morphological investigation, karyotype analysis (Ohta, 1962; Shopova, 1966; Pickersgill, 1977) and the study of breeding behavior (Pickersgill, unpubl.; Eshbaugh, 1975). We use the technique of starch gel electrophoresis to provide data for a different perspective of evolution in Capsicum. Re-