Preliminary Study On Wide Cross Breeding Of Rose V—Shrub Roses

In this study, the wild rose and chinese traditional rose as male parent, as well as Chinas and modern roses with excellent ornamental characters as the female parent were chosen for cross breeding research. The effect of the microbial agent, stratification medium, NaHCO3solution and activated carbon on dormancy breaking and germination of rose seeds were also studied. The main results of this thesis are as follows:1.48varieties of modern roses and chinas as female parent were selected in this study,23varieties were tested by using flow cytometry at ploidy level,18of them were tetraploid,4varieties were diploid,1varietie was triploid.2. In order to obtain new cultivars of shrub rose with strong resistance, Rosa primula, Rosa xanthina f. spontanea. Rosa laxa with strong resistance and good shrub traits, and part of Rosa ’Parsons’ Pink China’and Rosa ’Ruanxianghong’as male parents, combining with morden roses as female parents were chosen to design77cross combinations. A total of1183flowers were pollinated,127hips and690mature hybrid seeds were obtained. Only2seedlings were obtained from hybrid seeds in2011, while31seedlings were obtained in2012. The higher cross-compatibility groups with more than50%fruit setting rate are:’George Vancouver’×R.laxa,’William Baffin’×R.laxa,’Purple Heart’×R.laxa,’Black Cherry’×R.laxa. while lower cross-compatibility groups with30-50%fruit setting rate are:’Parsons’Pink China’×R.primula,’Odorata"×R.laxa,’Love’X R.laxa,’Lilac Rose"×R. laxa,’Yellow Dagmar Hastrup"×R.laxa,"Autumn Sunset’×R.laxa.3. The heterozygosity of hybrid seedling was identified by morphology and ploidy identification. One hybrid seedling of’Parsons’Pink China"×R. primula was testified as true hybrid4. After the warm stratification for4weeks and cold stratification for12weeks, the Sporotrichum Thermophile agent showed a positive effect on R.laxa germination. with57.3%germination rate. Straw cellulose-decomposing microbes and Sporotrichum Thermophile agent can break seed dormancy of the specie R.brunonii. at a significant level with the maximum germination rate of13.3%. Humus soil plus activated carbon is most suitable for seed germination of Rosa brunonii with germination rate of76.7%, followed by Kanuma soil plus activated carbon (65.6%) and sand plus activated carbon (54.4%). The seed germination rate of R.laxa was significantly increased at NaHCO3concentration value of0.1%,0.5%,1%and3%, and germination rates are84.3%,85.6%,85.6%and80.0%respectively, which were significantly higher than the control group(50.0%).