CYTOGENETIC CHARACTERIZATION OF THE GERMPLASM OF WILD CHILI PEPPERS: CAPSICUM EXIMIUM

AGUILERA, P.M.; DEBAT, H. J.; GRABIELE, M.

TAXON

INT ASSOC PLANT TAXONOMY

Lugar: Viena; Año: 2017 vol. 66 p. 6 - 8

0040-0262

In: Marhold K (ed.), IAPT/IOPB chromosome data 26. TAXON 66(6): 2 (edición impresa resumida, ISSN 0040-0262); E6-E7 (online full version, ISSN 1996-8175). Capsicum eximium is a wild hot chili pepper native to south Bolivia and northwest Argentina, occurring at Jujuy, Salta and Tucuman provinces of this country. The species grows as an herb, shrub or tree (0.6-6 m), with stellate flowers, white with violet lobules, greenish in the tube, and spherical red hot fruits. In Bolivia, given its pungent nature, C. eximium is used as a spice. The metaphase 45S rDNA FISH pattern of C. eximium presented here is consistent with five chromosome pairs that hold ten ribosomal signals of different size at terminal regions (p2, 5, 12; q7, 11). In addition, four of the 45S rDNA FISH signals occurred at the expected active NOR chromosome pairs nos. 7 and 12, respectively. Extra 45S rDNA loci at chromosome pairs nos. 2, 5 and 11 are NOR-inactive and were revealed as CMA enhanced (CMA+) highly GC-rich cHet regions in earlier analysis. Collectively, the 45S ribosomal fraction comprises 2.26 µm (3.21%) of the haploid genome of C. eximium and the ratio of euchromatin to rDNA in this taxon is 20.87:1. The present FISH approach by means of a Capsicum specific 45S rDNA probe in the wild hot chili pepper C. eximium permitted to uncover a detailed and comprehensive cytological map for this taxon. In this sense, each chromosome of the complement can be further recognized via different markers, either morphological and/or related to rDNA and cHet.