Cytogenetic characterization of three Argentinian populations of Rhodophiala bifida (Amaryllidaceae)

DAVIÑA, JULIO, R.; BRUERA, CAMILA, R.; HONFI, ANA I.

Foz do Iguaçú

Congreso; International Congress of Genetics; 2018

Sociedade Brasileira de Genética

Rhodophiala bifida is a bulb endemic species from South America with potential ornamental value conferred by its large-sized and red-colored zygomorphic flowers, despite this, there are few cytogenetic studies available on this native taxon. The aim of this work is to provide a karyomorphological description of three natural populations of R. bifida (B1, H1867, Misiones; G21, Buenos Aires) from Argentina. Chromosomes were analyzed by classical Feulgen technique and asymmetry was analyzed by several indexes. Idiograms were drawned using FreeCAD v0.16. Two populations have 2n = 18 and the other 2n= 18+2B. B chromosomes are polytipic, not polymorphic, in analyzed populations and both shares the same morphology and size. Species karyotypes are bimodal and asymmetric which formulaes are composed by 4 m + 14 sm (B1, G21) or 4 m + 14 sm + 2 B (H1867). Small differences in total chromosome length (TCL) were observed between populations, 138.2 μm (G21), 156.2 μm (B1 population) and 152.4μm (H1867). Stebbins´ category of asymmetry was the same for B1 and G21 population karyotypes (3B) but not for H1867 (3A), if B chromosomes are considered. This is the first karyotype description and report of homozigous two B chromosomes presence in R. bifida.