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. 2 n = 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 2 n = 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 2 n = 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.

Meiotic analysis of interspecific hybrids between Capsicum frutescens and Capsicum chinense

“…The meiotic analysis of the hybrids allowed observing 12 chromosomes in bivalent association in diakinesis (Figure 1a), corroborating the literature for diploid parental species, with 2n=2x=24 chromosomes (Pozzobon et al 2006, Moscone et al 2007). This result is expected, since the parental species, C. frutescens and C. chinense, differ only by the presence of an annular constriction in the calyx, typical of the species C. chinense (IPGRI 1995).…”

Meiose e viabilidade polínica em acessos de Capsicum annuum e Capsicum baccatum

“…A análise meiótica dos acessos permitiu observar 12 cromossomos em associação bivalente, em diacinese e metáfase I (Figura 1a e 1b, respectivamente), corroborando o que a literatura registra para essas espécies conhecidas como diploides, com 2n=2x=24 cromossomos (POZZOBON et al, 2006;MOSCONE et al, 2007).…”

A Meiotic Study of the Wild and Semi-domesticated Brazilian Species of Genus Capsicum L. (Solanaceae)

“…var. praetermissum, C. chinense, C. flexuosum and C. parvifolium (2nϭ24) all other taxa have 2nϭ26 (Pozzobon et al 2006).…”

“…Morton & Stand., C. mirabile Martius, C. campylopodium Sendtner and 1 unidentified Capsicum sp. However, Pozzobon et al (2006) recently found 2nϭ26 for 9 more species from Brazil and suggested that xϭ12 and xϭ13 represent different evolutionary trends in the genus. Meiotic behavior evaluation has been performed in the xϭ12 wild and domesticated species as well as in some hybrids, aiming at verifying genomic diversification during evolution as well as possible inter-specific phylogenetic relations (Otha 1961, Lippert et al 1966, Shopova 1966a, 1966b, Carluccio and Saccardo 1977, Pickersgill 1971, 1977, 1991, Saccardo and Ramulu 1977, Egawa and Tanaka 1984, Mirkova and Molchova 1985, Kumar et al 1987, Raghuvanshi and Saxena 1991, Moscone 1992, Bapa Rao et al 1992, Lanteri and Pickersgill 1993, Tong and Bosland 1999, Panda et al 2004.…”