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

In this paper, the compatibility and fertility of Chinese and Japanese cultivar groups of Paeonia ×suffruticosa were investigated by crossing, and hybrid embryos with or without endosperm were cultured in vitro on different media to evaluate the value of in vitro culture in tree peony breeding.
The main results were:

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.

XXVII International Horticultural Congress – IHC2006: International Symposium on Ornamentals, Now!

Fangyun Cheng, Noriaki Aoki

Chinese cultivar, cross, embryo culture, Japanese cultivar, tree peonies (P. ×suffruticosa)

https://doi.org/10.17660/ActaHortic.2008.766.48