CROSSES OF CHINESE AND JAPANESE TREE PEONY AND A PRIMARY STUDY ON IN VITRO CULTURE OF HYBRID EMBRYOS

1. Chinese and Japanese groups were entirely compatible with each other according to the results from 14 combinations including regular, reserve and self-crosses, but the fertility varied between combinations, especially the female stock. Hybrid seeds normally germinated into seedlings after passing a cold- or GA₃ -treatment stage.
2. 1/2 and full-strength MS media were optimal for younger embryos before harvest and mature ones at harvest, respectively, but they had the same effect on post-mature embryos after harvest. The germination of embryos cultured in vitro was significantly inhibited when the endosperm was attached to them.
3. Cultured-embryo seedlings established well after about 2 months. Their growth was accelerated so much with the disappearance of epicotyl dormancy that 5-6-month-old seedlings were comparable to two-year-old seedlings from germinated seeds. Therefore, embryo culture in vitro should be a versatile technique benefiting the breeding of tree peony.

Download Adobe Acrobat Reader (free software to read PDF files)