Studies on Pollen Viability and Its Storage Conditions of Pingyin Rose Studies on Pollen Viability and Its Storage Conditions of Pingyin Rose Research on Quantitative Taxonomy of Cultivars in Pingyin Rose Studies on Pollen Submicroscopic Morphology and Cultivars Classification inPingyin Rose Research on Quantitative Taxonomy of Cultivars in Pingyin Rose Studies on Pollen Submicroscopic Morphology and Cultivars Classification inPingyin Rose The Effect of Polyphenol Content and Polyphenol Oxidase Activity on in VitroRooting of Pingy in Rose Cultivars The Effect of Polyphenol Content and Polyphenol Oxidase Activity on in VitroRooting of Pingy in Rose Cultivars