为实现梅花(Prunus mume)高效遗传转化, 并为梅花遗传改良奠定技术基础。以早绿萼、单粉垂枝、香瑞白和香雪宫粉4个梅花品种叶片为外植体, 以WPM为基本培养基, 探讨不同种类与浓度的植物生长调节剂对不同梅花品种叶片愈伤组织诱导效率的影响, 并以香瑞白愈伤组织为受体材料, 采用农杆菌介导法, 探究并优化菌液浓度、侵染时间、共培养时间3个关键转化参数对愈伤组织遗传转化的影响。结果表明, 不同梅花品种的最佳愈伤组织诱导培养基及诱导率存在差异。早绿萼与香瑞白的最佳愈伤组织诱导培养基均为WPM+1.0 mg∙L–1 6-BA+1.0 mg∙L–1 TDZ+0.5 mg∙L–1 2,4-D, 诱导率最高分别为61.70%和66.67%; 单粉垂枝最佳愈伤组织诱导培养基为WPM+1.0 mg∙L–1 6-BA+0.5 mg∙L–1 TDZ+0.3 mg∙L–1 2,4-D, 诱导率最高可达84.38%; 香雪宫粉最佳愈伤组织诱导培养基为WPM+0.5 mg∙L–1 6-BA+0.5 mg∙L–1 TDZ+1.0 mg∙L–1 2,4-D, 诱导率最高为66.67%。以香瑞白愈伤组织为材料的遗传转化实验表明, 最适宜条件为菌液浓度OD600=0.7, 侵染15分钟, 共培养5天, 转化率最高为17.00%。研究表明4个梅花品种愈伤组织诱导所需植物生长调节剂存在显著的品种特异性, 在此基础上成功获得香瑞白阳性转基因愈伤组织, 为梅花重要性状的基因功能验证和遗传改良提供技术支撑。

INTRODUCTION: Prunus mume, a renowned traditional flower in China, plays a significant role in garden landscapes. However, conventional artificial hybridization breeding methods for P. mume face challenges such as lengthy breeding cycles and limited genetic variation. Therefore, establishing an efficient regeneration and genetic transformation system for P. mume is of great importance for its breeding advancement. 

RATIONALE: To establish an efficient genetic transformation system for P. mume and lay a technical foundation for its genetic improvement, leaves from four cultivars (Zao Lve, Danfen Chuizhi, Xiang Ruibai, and Xiangxue Gongfen) were used as explants. Based on WPM medium, the effects of different types and concentrations of plant growth regulators on callus induction efficiency were systematically evaluated. Using callus derived from Xiang Ruibai, an Agrobacterium-mediated transformation method was applied to optimize three key parameters—bacterial suspension concentration, infection time, and co-cultivation time—and to assess their impacts on transformation efficiency. This study provides a foundation for establishing a complete and efficient genetic transformation system for P. mume. 

RESULTS: The optimal callus induction medium and induction rates varied among different P. mume cultivars. For Zao Lve and Xiang Ruibai, the most effective medium was WPM supplemented with 1.0 mg∙L–1 6-BA, 1.0 mg∙L–1 TDZ, and 0.5 mg∙L–1 2,4-D, achieving induction rates of 61.70% and 66.67%, respectively. For Danfen Chuizhi, the best medium was WPM with 1.0 mg∙L–1 6-BA, 0.5 mg∙L–1 TDZ, and 0.3 mg∙L–1 2,4-D, resulting in an induction rate of 84.38%. For Xiangxue Gongfen, the optimal formulation was WPM containing 0.5 mg∙L–1 6-BA, 0.5 mg∙L–1 TDZ, and 1.0 mg∙L–1 2,4-D, which yielded an induction rate of 66.67%. In genetic transformation experiments using callus from Xiang Ruibai, the highest transformation efficiency (17.00%) was obtained under the following conditions: bacterial suspension OD600=0.7, infection time of 15 minutes, and co-cultivation period of 5 days. 

CONCLUSION: This study systematically compared the hormone requirements of four P. mume cultivars, revealing significant cultivar-specific differences in callus induction. Based on these findings, the positive transgenic callus of Xiang Ruibai was successfully obtained. This provides a technical foundation for verifying gene functions and conducting genetic improvement of important traits in P. mume.