Genomic relationships between Turnera orientalis (Urb.) Arbo (6x) and T. occidentalis Arbo & Shore (6x) (Turneraceae, subseries Turnera)

LOPEZ, ALICIA; POGGIO, LIDIA; FERNÁNDEZ, AVELIANO

ANNALES BOTANICI FENNICI

FINNISH ZOOLOGICAL BOTANICAL PUBLISHING BOARD

Año: 2009

0003-3847

Aiming to differentiate Turnera orientalis (2n=6x=30) from Turnera occidentalis (2n=6x=30), classic and molecular cytogenetic techniques were used. Numerous hybrids were obtained from controlled crosses between T. orientalis and T. occidentalis. The analysis of their pollen viability and the failure to obtain F2 provided evidence of reproductive isolation. The present study reports for the first time the karyotype 22 metacentric + 8 submetacentric for T. occidentalis, and confirms the karyotype of T. orientalis. These species differ in the chromosome pair with secondary constriction and satellite. FISH analysis of these species showed six rDNA sites located on different chromosome pairs.  Although the meiotic chromosome pairing of hybrids suggested a close relationship of the two species, the karyotype and mapped location of rDNA sites were different between both taxa supporting that T. orientalis and T. occidentalis are two distinct species