Study On Hybrid Breeding And Cross Compatibility Of Prunus Mume

Mei flower(Prunus mume),one of the traditional Chinese flowers,mainly located in Changjiang River,Zhujiang River and southwest China.It also has a long history of cultivation and application.Currently cultivars of cold-resistant Mei flower have bred,but most of their flowers are white,light pink and losing typical fragrance.In order to breed new cultivars of Mei with cold resistant,fragrant,bright color and leaves colored,hybrid breeding and embryo culture were carried out.And pollen tube growth,dynamic change of fruit setting rate,embryo culture was preliminary studied.From the above researches,it could aim to explore cross-compatibility and breeding new cultivars in Mei flower.The main results are as follows:1.P.mume ’Xiang Ruibai’,P.mume ’Dan Fenghou’,P.mume ’Meiren’ were used as female parent.Male parent includes 7 interspecies and 26 intraspecies hybridization combinations.70 crosses were conducted and 22135 flowers were pollinated including 16 interspecific crosses of 7898 flowers and 54 intraspecific crosses of 14237 flowers.Interspecific crosses obtained 85 seeds,breeding l seedling(P.mume ’Dan Fenghou’×P.persica ’Baihua Shanbitao’).Intraspecific crosses obtained 1048 seeds,breeding 328 seedlings,which consist of 48 seedlings using P.mume ’Xiang Ruibai’ as female parent,245 seedling using P.mume ’Dan Fenghou’ as female parent,35 seedling using P.mume’Meiren’ as female parent.2.Interspecific crosses of P.mume were generally low in fruiting rate.The highest one was P.mume ’Dan Fenghou’×P.persica ’Baihua Shanbitao’ which was only 4.43%.The interspecific crosses using P.mume ’Meiren’ as female parent did not obtain hybrid seed,all of which are showing obvious cross incompatibility.3.The crosses using P.mume ’Xiang Ruibai’ and P.mume ’Dan Fenghou’ as female parent,which hybrid fruiting rate was 15%in mean.However,the crosses using P.mume’Meiren’ as female parent,the average fruiting rate was only 4.01%.Even there was great different in some crosses.Several excellent male parents were selected,including P.mume ’Chaotang Gongfeng’,P.mume ’Kouban Dahong’,P.mume `Midan Tiaozhi’,P.mume ’Fentai Chuizhi’,P.mume ’Duo’e Zhusha’.4.Incompatible pollen tubes were observed in interspecific crosses with fluorescent microscope,which appearing as pollen tubes twined,twisted,ends enlarged.Whereas pollen tubes could observed in the ovary after pollination 120h.P.mume ’Meiren’ × P.persica ’Dan Fen’ presented better compatibility,its pollen tubes’ growth velocity was rapider and the percentage of these penetrated ovary was higher.In intraspecific crosses,pollen tubes observed in the ovary after pollination 96h.But the percentage of these penetrated ovary was different from combinations.5.Slight difference in interspecific crosses and intraspecific crosses after pollination 10d in P.mume.However,the fruit setting rate of interspecific crosses was higher than intraspecific crosses during 10～30d after pollination.During 40d after pollination,the fruit setting rate was close to zero in interspecific crosses.6.Embryo culture is a good way to obtain P.mume ’Meiren’ seedlings rapidly.The most suitable medium for embryo culture was 2/3 WPM+0.0 mg/L 6-BA+0.0 mg/L IBA+1.0 g/L acticarbon.