Chromosome numbers in wild and semidomesticated Brazilian Capsicum L. (Solanaceae) species: do x = 12 and x = 13 represent two evolutionary lines?

Abstract

Chromosome numbers were determined in 29 accessions of wild and semidomesticated Capsicum species from the EMBRAPA Hortaliças (Brazil) germplasm collection. 2n = 24 was found in C. baccatum var. praetermissum, C. chinense, C. flexuosum and C. parvifolium, while C. buforum, C. campylopodium, C. cornutum, C. schottianum, C. villosum var. villosum and five other native south-eastern Brazilian species not yet taxonomically named all had 2n = 26 chromosomes. These are the first chromosome number determinations for C. cornutum, C. schottianum, C. villosum var. villosum and the five other Brazilian taxa. Our data confirm published data for C. baccatum var. praetermissum, C. campylopodium, C. chinense, C. flexuosum and C. parvifolium, but not for C. buforum. The prevalence of 2n = 26 chromosomes among Brazilian species, along with the morphological and ecological characteristics presented by the wild and semidomesticated species occurring in Brazil, form a pattern different from that found in Andean wild and semidomesticated species. This supports the hypothesis that there are two different evolutionary lines in the genus and that the native south-eastern Brazilian species belong to the ancestral Capsicum gene pool.

cytogenetics, cytotaxonomy, morphology, peppers