Interspecific hybrids between <Emphasis Type="Italic">Dendranthema morifolium</Emphasis> (Ramat.) Kitamura and <Emphasis Type="Italic">D. nankingense</Emphasis> (Nakai) Tzvel. achieved using ovary rescue and their cold tolerance characteristics

Ovary rescue was employed to create six interspecific hybrids from the cross between Dendranthema morifolium (Ramat.) Kitamura ‘rm20-12’ (2n = 54) and its wild diploid relative D. nankingense (Nakai) Tzvel. (2n = 18). The morphology of the hybrids differed from that of either parent. The leaf length and width of all three D. morifolium × D. nankingense hybrids exceeded that of the parents, as did the plant height of two and the inflorescence diameter of another of the hybrids. One of the reciprocal hybrids was heterotic for leaf length and width. All the hybrids bore yellow flowers. The cold tolerance of five hybrids was significantly superior to that of their D. morifolium parent. Interspecific hybridization clearly provides an effective means of cultivar improvement in chrysanthemum.