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 microsporederived 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.