STUDIES ON THE INVESTIGATION AND INTRODUCTION OF THE WILD FLOWER PAEONIA SUFFRUTICOSA ANDR.VAR.PAPAVERACEA (ANDR.) KERNER IN SHENNONGJIA Ultrastructural studies of microsporogenesis and development of male gametophyte in Paeonia suffruticosa Comparison of Photosynthetic Characteristics between Potted and Field Paeonia suffruticosa Andr. Efficient Induction of Callus and Plant Regeneration From Paeonia suffruticosa Andr Propagation with Etiolated Softwood Cuttings of Five Dwarf Cultivars ofChinese Tree Peony Propagation with Etiolated Softwood Cuttings of Five Dwarf Cultivars ofChinese Tree Peony Comparison of Photosynthetic Characteristics between Potted and Field Paeonia suffruticosa Andr. ISSR analysis on genetic diversity of Paeonia suffruticosa in Hunan province