Chimonanthus praecox is an important ornamental plant and cut flower material in China. It blooms in the freezing winter and its flower emits charming fragrance. However, in different region the flowering time is variable. In order to understand the flowering mechanism of Ch. praecox in the winter, we studied the flower bud differentiation in Spring City-Kunming using paraffin sectioning method in the present study. Meanwhile we compared the differentiation process difference from different regions. It was found that the temperature is the key factor for its flower bud differentiation and blossom of Ch. praecox. In the process of bud differentiation, the temperature 20 °C was the optimum for inducing changes from vegetative axillary buds to reproductive buds and subsequent morphological differentiation in Ch. praecox. Furthermore in the first three differentiation periods—tepal primordial stage, staminal primordial stage and pistil primordial stage, Kunming took the shortest time to finish the process due to very rapid temperature rise to 20 °C, whereas, in Zhengzhou the time for these differentiations was the longest, which may be caused by the slow temperature rise. After May, the high temperature stress forced the flower buds into the first long dormant period in all regions except Kunming. In Kunming, the average temperature was only 20–25 °C, so the flower bud continued to differentiate. In all regions, Kunming is the first to complete whole flower bud differentiation even on the early August, and started the second dormancy very early but very long. In the other regions, the plants went through a shorter dormancy and the low temperature broke the dormancy rapidly. Contrarily the plants of Kunming spent a longer period for the low temperature. Thus, the low temperature less than 10 °C is a key factor to breaking the second dormancy. Surely the regular effects of temperature on flower bud differentiation and blossom is very helpful for florescence regulation of Ch. praecox.

Chimonanthus praecox是我国重要的观赏植物和切花材料。它在寒冷的冬天开花，它的花朵散发出迷人的香气。但是，在不同的地区，开花时间是可变的。为了了解Ch的开花机制。本研究采用石蜡切片法对春城-昆明的花芽分化进行了研究。同时我们比较了不同地区的分化过程差异。研究发现，温度是其花芽分化开花的关键因素。早泄. 在芽分化过程中，20 ℃是诱导植物腋芽向生殖芽转变和随后形态分化的最佳温度。早泄. 此外，在前三个分化期——花被初生期、雄蕊初生期和雌蕊初生期，昆明由于温度上升到20℃的速度非常快，完成该过程的时间最短，而在郑州，这些分化的时间是最长，可能是温度上升缓慢造成的。5月以后，高温胁迫迫使除昆明以外的所有地区的花蕾进入第一个长休眠期。在昆明，平均气温只有20～25℃，花芽继续分化。在所有地区，昆明是第一个在8月初完成全花芽分化的，第二次休眠很早但很长。在其他地区，植物经历了较短的休眠期，低温迅速打破了休眠期。相反，昆明的植物受低温影响的时间更长。因此，低于10℃的低温是打破第二次休眠的关键因素。当然，温度对花芽分化和开花的规律性影响对花期调控很有帮助。通道。早泄。