抄録
The ploidy level of Cyclamen rohlfsianum was analyzed through the measurement of the relative fluorescent intensity (RFI) of nuclei stained with 6-diamidino-2-phenylindole (DAPI) using flow cytometry (FCM), and through the observation of mitotic and meiotic chromosomes, as compared with those of C. persicum (2n=2x=48, Cpe2x), C. rohlfsianum (Cro2, 2n=96), C. purpurascens (2n=2x=34, Cpu3) and a hybrid (2n=65) of C. rohlfsianum (Cro2, 2n=96)×C. purpurascens (2n=2x=34, Cpu3). The mean chromosome pairing at diakinesis and/or metaphase I of PMCs in Cro2, Cpu3 and their hybrid was 0.65I+47.07II+0.03III+0.28IV, 0.16I+16.92II and 17.00I+24.00II, respectively. These findings suggest that Cro2 is an autotetraploid (2n=4x=96) and the Cro2×Cpu3 hybrid is an allotriploid (2n=3x=65), produced by crossing an autotetraploid and diploid. The chromosome number of Cro3 was 2n=144, equal to 1.5 times that of Cro2 (2n=4x=96) and the DNA content of Cro3 estimated by the RFI value corresponded to approximately 1.5 times that of Cro2, suggesting that Cro3 is an autohexaploid (2n=6x=144). Twelve C. rohlfsianum plants of uncertain chromosome number were classified into 3 autotetraploids and 9 autohexaploids by FCM analysis, suggesting intraspecific differentiation concerning the ploidy level in C. rohlfsianum.
