TAXONOMIC AND GENETIC STUDIES ON THE CULTIVATED PEPPERS, CAPSICUM ANNUUM L. AND C. FRUTESCENS L.

Abstract

DURING A BREEDING program with cultivated peppers, the senior author received seed of an unusual type (P. I. 129,325) from the Division of Plant Exploration and Introduction, United States Department of Agriculture. This lot-listed on receipt as Accession 390-had been collected in an abandoned field north of Santa Rosa, Province of El Oro, Ecuador. It was found to differ materially from typical cultivated varieties, except Tabasco, a type which it strongly resembled. Subsequent attempts to hybridize Tabasco and Ac. 390 with other cultivated varieties have been largely unsuccessful, although the two readily crossed with each other. At the present time the varieties of pepper commonly cultivated are considered by most horticulturists and taxonomists in the United States to constitute a single species, Capsicum frutescens L. The difficulty in hybridizing Tabasco and Ac. 390 with other cultivated varieties suggested that these two forms belong to a distinct species. Recently, a number of collections belonging to the TabascoAc. 390 type have been grown, and detailed taxonomic investigations have been undertaken. On the basis of crossing experiments and morphological studies of a large collection of living material, we are convinced that there are valid grounds for retention of two species for the commonly cultivated peppers. HISTORY.-In his Hortus Cliffortianus of 1937, Linnaeus described two species of Capsicum -C. annum and C. frutescens-and in his Mantissa of 1767, two additional ones-C. grossum and C. baccaturn. During the next 100 years, over fifty new species were proposed-most of which were based on cultivated material. Irish (1898) accepted only Linnaeus' two original species and stated that all the leading commercial varieties should be referred to C. annum. Bailey (1923) recognized only one cultivated species and chose the name C. frutescens in preference to C. annuum. Erwin (1932) accepted Bailey's treatment and assigned all the varieties he studied to C. frutescens, and Miller and Fineman (1937), on the basis of hybridization experiments, supported the taxonomic views of Bailey and Erwin. Shaw and Khan (1928) recognized two cultivated species in India, using the names C. frutescens and C. annuum. Bravo (1934) also recognized both species among Mexican peppers. The name, Capsicum frutescens, has been generally used in the United States for cultivated peppers, whereas authors elsewhere-following the