Cytogenetic studies on wild Chrysanthemum from China. V. F1-hybrids of Chrysanthemum lavandulaefolium var. sianense*Ch. boreale.

The karyotypes and chromosome configurations in the F1-hybrids between Chrysanthemum lavandulaefolium var. sianense from China and Ch. boreale from Japan were investigated.2. The karyotype of sianense is more primitive than that of boreale, because sianense has more symmetrical karyotype and more satellite chromosome than boreale. Therefore, it is assumed that sianense is a primitive species in genus Chrysanthemum.3. In spite of the small difference in the karyotypes of both species, the genomes of both species are almost homologous because of the high rate of homomorphic bivalent formation in their F1-hybrids.