Crossing Breeding On Secondary Blooming Tree Peony And Identification In The Early Stage

Tree peony (Peaonia suffruticosa Andr.) is a Chinese traditional ornamental plant with a long history in cultivation and wide application.But because of its concentrated florescence,its industrialization is limited. So prolonging the florescence and making it blossom in different seasons are very necessary for further development. Autumn flowering tree peonies usually re-bloom in autunm or winter unstably and in poor quality.They are not real secondry blooming cultivars.This paper chose some Secondary blooming cultivars to try to get some new hybrids which will re-bloom in autunm or winter stably. The author also provided a relatively simlpe and accurate method for early stage identification. The main results are as follows:The pollen grain viability test showed that at normal atmospheric temperature, the storage time of P.ostii, P.rockii, and P.delavayi were the longest, followed by P. suffruticosa Japan Group, autumn flowering caltivars, and it is proved that low temperature helped to extend the viability period of the pollen grains.49 cross-combinations were selected in crossing experiment, the parents included closed hybridization inside subsect.Vaginatea, hybridization between Subsect.Vaginatea and Subsect.Delavayanae.511 flowers and 1181 seeds were obstained,and from which 87 seedlings were grown until March 2011.There were 504 seeds from hybridization of Subsect.Vaginatea,from which 19 seedlings were grown.There were 677 seeds obstained from hybridization between two subsects, from which 68 seedlings were grown. P.delavayi×P.rockii, P.delavayi×'Lian He', P.ostii'Feng Dan Bai'x'Qiu Fa 1 Hao'and P.rockii×Qiu Fa 6 Hao'got higher setting percentage.The seed germination test indicated that the media of peat could raise rooting rate and improve the quality of roots; By treating roots with 400 mg/L GA for 2 hours, seed germination was accelerated.478 hybrid seeds were taken back to the laboratory and were treated in this way for germination, parts of germinated seedlings were selected for hybriding identification.The comparison between offsprings and their parents on leaf morphology, stomatal size, density and DNA showed that the real hybrids were close to the male parent on leaf morphology, and the size and density of stomatals were between the parents. Characteristics of leaf morphology and stomatal were not the indicators to identify the real hybrids in the early stage,. RAPD markers combing morphology might be a quickly and effective way for the hybrids indentifiction.