Karyological studies in Jaborosa (Solanaceae)

CHIARINI, FRANCO E.; BARBOZA, GLORIA E.

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

Año: 2008 vol. 156 p. 467 - 478

0024-4074

Sixteen species of Jaborosa (Solanaceae), including eight endemic to Argentina, were studied karyologically. The numbers n = 12 and/or 2n  = 24 were found in all species, the majority of the cases being new reports. Mitotic chromosomes are small to medium-sized, the average length varying from 2.95 to 4.93 mm. All species have 1-3 chromosome pairs with satellites. Karyotypes, obtained for 13 species, are slightly asymmetrical: A1 ranged from 0.228 to 0.483; A2 ranged from 0.095 to 0.182; Paszko’s asymmetry index, AI, ranged from 0.84 to 3.47. In all species, metacentric chromosomes are the most common, sub-metacentrics follow in frequency, whereas sub-telocentrics are rare. Morphological similarities or sectional arrangement were reflected neither in a Principal Components Analysis plot nor in plots of asymmetry indices, but the species can be singled out by their karyotype formulae and the different karyotype parameters taken. In Jaborosa, a notably diversified genus, exo-morphological evolution has taken place together with evident chromosome rearrangements, whose disposition is different and not as clear as in related genera.