Cytogenetic studies in Cyclamen persicum, C. graecum (Primulaceae) and their hybrids

Haploids, diploids and tetraploids of Cyclamen persicum (2n=x=24, 2x=48 and 4x=96), C. graecum (2n=84) and their interspecific hybrids (2n=45, 3x=66, 4x=90) were analyzed cytologically. The mean chromosome association per PMC at diakinesis or at metaphase I in meiosis was 23.29–23.39 I + 0.31–0.36 II in C. persicum (x), 0.17–0.23 I + 23.88–23.92 II in C. persicum (2x), 0.52–1.18 I + 46.39–46.78 II + 0.03–0.09 III + 0.41–0.48IV in C. persicum (4x) and 0.40–0.46I + 41.34–41.63 II + 0.02 III + 0.07–0.21IV in C. graecum. The mean chromosome association per PMC at diakinesis or at metaphase I was 0.47–0.62 I + 44.69–44.76 II in the hybrid (2n=90) of C. persicum (4x) × C. graecum, 38.48–42.50 I + 1.27–3.26 II in microspore-derived plants (2n=45) from the hybrid (2n=90) by anther culture and 26.22–26.67 I + 19.67–19.89 II in the hybrid (2n=66) of C. persicum (2x) × C. graecum. The results indicate that C. graecum is an autotetraploid, the hybrid (2n=4x=90) is an amphidiploid, the microspore-derived plant (2n=45) is a polyhaploid and the hybrid (2n=3x=66) is a sesquidiploid. Based on studies of meiosis, the ploidy levels and the origin of C. graecum and C. persicum are discussed in comparison with several species in the genus Cyclamen.