Studies of the embryo culture on the interspecific hybridization of Chrysanthemum

1. In th the crossings of _??_Chrysanthemum boreale 2x×_??_Ch. pacificum and _??_Ch. boreale 4x×_??_Ch. pacificum, the F1 hybrids usually can not be obtained. In these crossings the fertilization occurs, but the embryos collapse in the early stage of development. 2. In both crossings the embryos were excised before they collapsed and cultured in nutrient media. In Ch. boreale 2x×Ch. pacificum no F1 hybrid was obtained, while in Ch. boreale 4x× Ch. pacificum a F1 hybrid (2n=63) was raised. 3. The embryo culture was successful by using two media; the embryos were put into Brink's medium from which the yeast extract had been removed, and after germination, they were transferred into the medium which had been devised by the author.