1971 年 84 巻 996 号 p. 399-409
Two types of spontaneous polyploidy were found in the interspecific hybrids. One of those is the binucleate cells (24II+2BI at MI) which were observed with a frequency between 3 and 8 per cent in PMCs of Lilium×'Tsukiha' (2n=24+ IB, I2+ IB1), an artificial hybrid of L. maximowiczii 'Akatsuki'×L. purnilum 'Golden Gleam'. The other is a multiple allotriploid hybrid L. x 'Fire King' (2n=36, 12III), one of Stooke's Hybrids. The increase in ploidy in the latter may have arisen spontaneously from fertilization between a normal haploid gamete and an unreduced one during the breeding program.
The karyotypes of these two hybrids are heterozygous with respect to various secondary constrictions. The extent of chromosome pairing, however, indicates the close genomic relationships of the parental species.