摘要： 以梅树（Prunus mume Sieb. et Zucc.）早花品种‘粉红朱砂’（‘Fenhong Zhusha’）和‘淡妆宫粉’（‘Danzhuang Gongfen’），中花品种‘淡粉’（‘Dan Fen’）和‘寒红’（‘Han Hong’），以及晚花品种‘南京红’（‘Nanjing Hong’）和‘晚跳枝’（‘Wantiao Zhi’）为研究对象，对花芽发育过程中花芽的纵径和横径、外部形态和纵剖面结构以及鳞片开裂率进行了测量和观察，并采用RT-qPCR技术分析了花芽中成花基因pm-FD3、pm-AP2和pm-LFY以及看家基因S3a、homol、hsc、somX2、FRIGIDA-like和Subunit37e的相对表达量变化。观察结果显示：供试6个梅树品种花芽的纵径和横径随花芽发育整体呈增大趋势，在花芽发育早期增长迅速，且早花品种的花芽生长速率最快，晚花品种较慢。6个品种中，品种‘粉红朱砂’花芽鳞片开裂率最大，且在2018年1月16日超过50％，而在2018年1月24日前其余5个品种花芽鳞片开裂率均低于50％；总体上看，花芽鳞片开裂率以早花品种最高，晚花品种最低。根据花芽发育的各项指标，确定品种‘粉红朱砂’、‘淡妆宫粉’、‘淡粉’、‘寒红’、‘南京红’和‘晚跳枝’的开花日期分别为2018年的1月16日、2月11日、2月15日、2月23日、2月28日和3月4日。RT-qPCR分析结果显示：在梅树花芽发育过程中，成花基因和看家基因的表达特性以及相对表达量明显不同。其中，pm-LFY和Subunit37e基因在6个品种的花芽发育过程中均持续表达，而pm-FD和FRIGIDA-like基因仅在中花和晚花品种的花芽发育过程中持续表达，其余基因均间断表达；早花品种的成花基因和看家基因的最高表达日期总体上早于中花和晚花品种，且距开花日期的间隔天数也明显短于晚花品种；此外，有些成花基因与部分看家基因的最高表达日期一致或相近。综合分析结果表明：在梅树花芽发育过程中，其花芽结构和外部形态变化以及成花基因和部分看家基因的高表达特性均与其花期早晚相对应；早花品种“早开花”的特性与部分基因的快速启动有关，对花芽中成花基因和看家基因的相对表达量进行分析有助于梅树花期的预测。

Taking earlyflowering cultivar ‘Fenhong Zhusha’ and ‘Danzhuang Gongfen’， middleflowering cultivar ‘Dan Fen’ and ‘Han Hong’， and lateflowering cultivar ‘Nanjing Hong’ and ‘Wantiao Zhi’ of Prunus mume Sieb. et Zucc. as research objects， their vertical and horizontal diameters， external morphology， longitudinal section structure， and scale cracking ratio of flower bud during their development progress were measured and observed， meanwhile changes in relative expression levels of flowering gene pm-FD3， pm-AP2 and pm-LFY， and house-keeping gene S3a， homol， hsc， somX2， FRIGIDA-like and Subunit37e in flower bud were analyzed by using RTqPCR technology. The observation result shows that vertical and horizontal diameters of flower bud of six cultivars of P. mume tested show a tendency to increase with development of flower bud in general， and grow fast in early development stage of flower bud， flower bud growth rate of early-flowering cultivars is the fastest， while that of late-flowering cultivars is slower. Among six cultivars， scale cracking ratio of flower bud of cultivar ‘Fenhong Zhusha’ is the largest， which exceeds 50％ on January 16， 2018， while that of other five cultivars is lower than 50％ before January 24， 2018； in general， that of early-flowering cultivars is the highest， while that of late-flowering cultivars is the lowest. According to each development index of flower bud， flowering dates of cultivar ‘Fenhong Zhusha’， ‘Danzhuang Gongfen’， ‘Dan Fen’， ‘Han Hong’， ‘Nanjing Hong’ and ‘Wantiao Zhi’ are January 16， February 11， February 15， February 23， February 28 and March 4 in 2018， respectively. The RT-qPCR analysis result shows that expression characteristics and relative expression levels of flowering- and house-keeping genes are evidently different during development progress of flower bud of P. mume. In which， pm-LFY and Subunit37e genes continuously express during development progress of flower bud of six cultivars， while pm-FD and FRIGIDA-like genes only continuously express during development progress of flower bud of middle- and late-flowering cultivars， and other genes all discontinuously express； the highest expression dates of flowering and house-keeping genes of early-flowering cultivars are earlier than those of middle- and late-flowering cultivars in general， and their interval days to flowering date are evidently shorter than those  of late-flowering cultivars； in addition， the highest expression dates of some flowering and house-keeping genes are identical or similar. The comprehensive analysis result shows that structure and external morphology change of flower bud and high expression characteristics of flowering and some house-keeping genes all correspond to the date of flowering period during development progress of flower bud of P. mume； “early flowering” characteristics of early-flowering cultivars are associated with fast initiation of some genes， and analysis on relative expression levels of flowering and house-keeping genes in flower bud can help to predict flowering period of P. mume.