Low-temperature accumulation is one of the essential stages in the growth process of woody ornamental plants. In this study, two different low-temperature treatments, 6 °C and 10 °C, were used to analyze the effects of different low-temperature treatments on dormancy release and flowering of the ‘Gulihong’ plant using artificial low temperatures. Based on the experimental results, four typical early-blooming Prunus mume cultivars widely planted in Yangling area of Henan Province, China, including ‘Zaoyudie’, ‘Zaohualve’, ‘Nanjing gongfen’, and ‘Gulihong’, were selected as the experimental materials. The effects of low-temperature accumulation on the flowering characteristics of different cultivars were analyzed using a 6 °C artificial low-temperature treatment. The suitable cultivation temperature for early-blooming cultivars was screened to provide a theoretical basis for further exploration of P. mume bonsai cultivation techniques. The results showed that the flowering rate, flower diameter, flowering quantity, flowering uniformity, and bud development in the 6 °C treatment were significantly better than those in the 10 °C treatment. Furthermore, under 6 °C low-temperature treatment, the flowering rate and quality of different cultivars showed an increasing trend with the accumulation of low temperature, with ‘Gulihong’ exhibiting the highest flowering rate. Therefore, chill accumulation plays a significant role in promoting flowering quality.

Low temperature plays a vital role in the growth and development of woody plants. In this research, based on the ability of artificial low temperatures to break dormancy, the Utah model was used to determine the chilling requirements (CR) of four early flowering Prunus mume Sieb. et Zucc. (Rosaceae) cultivars, which are widely found in the Henan area of China. In addition, changes in the carbohydrates, antioxidant enzyme activities, and endogenous hormone contents of the flower buds (FBs) of the above-mentioned P. mume cultivars were measured during the low-temperature storage process, and the physiological changes of the four cultivars during the low-temperature induction period were explored. The main research conclusions are as follows: (1) the CRs of ‘Gulihong’, ‘Nanjing gongfen’, ‘Zaoyudie’, and ‘Zaohualve’ were 408CU, 396CU, 372CU, and 348CU, respectively. All the P. mume cultivars belonged to cultivars with a low chilling demand. They also bloomed 4 months earlier, and (2) during the process of releasing dormancy at low temperatures, the contents of soluble sugar (SS) in the osmoregulation system of the four Prunus mume cultivars showed an upward trend, while the content of starch (ST) basically showed an opposite trend to the increase in chilling. The superoxide dismutase (SOD) activity in the FBs of each cultivar gradually decreased with the increase in cold and remained at a low level, while the peroxidase (POD) activity showed an opposite trend, and the dynamic changes of the catalase (CAT) activity generally showed a trend of first increasing and then decreasing. The content of abscisic acid (ABA) showed a trend of increasing first and then decreasing as a whole. The changing trend of gibberellin (GA₃) content was similar to that of ABA. In addition, it was found that before dormancy was released, the SS and Pro contents of cultivars with lower CRs and early FB germination were significantly higher than those of other cultivars with higher CRs and the contents of ST and SP were lower. The cultivars with higher CRs and late FB germination had higher ABA content, lower GA₃ contents, and their enzyme activities were significantly higher than those of the cultivars with lower CR. Therefore, the changes in the content of various substances in FBs are related to the amount of cooling required by the cultivar and at what point the FBs germinate, and the changes in their contents can be used as one of the indicators for judging the dormancy process of FBs.

Low-temperature accumulation is one of the essential stages in the growth process of woody ornamental plants. In this study, two different low-temperature treatments, 6℃ and 10℃, were used to analyze the effects of different low-temperature treatments on dormancy release and flowering of the 'Gulihong' plant using artificial low temperatures. Based on the experimental results, four typical early-blooming Prunus mume cultivars widely planted in Yangling area of Henan Province, China, including 'Zaoyudie', 'Zaohualve', 'Nanjing gongfen', and 'Gulihong', were selected as the experimental materials. The effects of low-temperature accumulation on the flowering characteristics of different cultivars were analyzed using a 6℃ artificial low-temperature treatment. The suitable cultivation temperature for early-blooming P. mume cultivars was screened to provide a theoretical basis for further exploration of P. mume bonsai cultivation techniques. The results showed that the flowering rate, flower diameter, flowering quantity, flowering uniformity, and bud development in the 6℃ treatment were significantly better than those in the 10℃ treatment. The flowering rate and quality of different cultivars gradually increased with the accumulation of low-temperature. Therefore, chill accumulation plays a significant role in promoting flowering quality.

Low-temperature plays a vital role in the growth and development of woody plants. In this research, based on the way of artificial low temperature to break dormancy, the Utah model was used to determine the chilling requirements of four early-flowering Prunus mume cultivars, which were widely planted in Henan area of China. At the same time, changes in the carbohydrates, antioxidant enzyme activities, and endogenous hormone contents of the flower buds (FBs) of the above P.mume cultivars were measured during the low-temperature storage process, and the physiological changes of the four cultivars during the low-temperature induction period were explored. The main research conclusions are as follows: (1) The chilling requirements of ‘Gulihong’, ‘Nanjing gongfen’, ‘Zaoyudie’ and ‘Zaohualve’ were 408CU, 396CU, 372CU and 348CU respectively. All the P.mume cultivars belonged to low chilling demand cultivars. The P.mume also bloomed 4 months earlier (2) During the process of releasing dormancy at low temperature, the contents of soluble sugar (SS) in the osmoregulation system of the four Prunus mume cultivars showed an upward trend, while the contents of starch (ST) basically showed an opposite trend with the increase of chilling. The superoxide dismutase (SOD) activity in the FBs of each cultivar gradually decreased with the accumulation of cold and maintained at a low level, the peroxidase (POD) activity showed the opposite trend, and the dynamic changes of the catalase (CAT) activity generally showed a trend of first increasing and then decreasing. The content of abscisic acid (ABA) showed a trend of increasing first and then decreasing as a whole. The changing trend of gibberellin (GA3) content was similar to that of ABA. In addition, it was found that before dormancy was released, the SS and Pro contents of cultivars with lower chilling requirements and early FB germination were significantly higher than those of other cultivars with higher chilling requirements, and the contents of ST and SP were lower. The cultivars with higher chilling requirement and late flower bud germination had higher ABA content, lower GA3 contents, and their enzyme activities were significantly higher than those of the cultivars with lower chilling requirement. Therefore, the changes in the content of various substances in FBs are related to the amount of cooling required by the cultivar and the sooner or later the FBs germinate, and the changes in their contents can be used as one of the indicators for judging the dormancy process of FBs.

Heat requirements play an important role in plant flowering, and control the flowering period of woody ornamental plants to a certain extent. In this study, the perennial potted seedlings of four typical Prunus mume cultivars 'Xiaolve', 'Baixuzhusha', 'Fenghou' and 'Danfenghou' were used as materials. The way of regulating the cultivation temperature is adopted to achieve the purpose of relieving the natural dormancy and forcing the blooming of P. mume. Its content includes the research on the heat requirements of P. mume cultivars widely planted in Beijing, and the analysis of the influence of different facility cultivation temperatures on the flowering characteristics of P. mume, providing a theoretical basis for further exploring the cultivation techniques of P. mume bonsai flowering regulation. The results showed that, according to the Growing degree-hour model, the HR of 'Xiaolve', 'Baixuzhusha', 'Fenghou' and 'Danfenghou' flower buds were 3583.70 GDH℃, 3217.30 GDH ℃, 3996.50 GDH ℃, 4732.20 GDH ℃, respectively. According to the effective accumulated temperature model, the HRs of above cultivars were 350.65 ℃, 319.30 ℃, 510.30 ℃, 558.50 ℃, respectively. In addition, the temperature of different cultivation facilities did not significantly change the flowering quality such as flower diameter and fragrance. Temperature also affects the growth and development speed, affecting the flowering time. Under the facility environment with higher temperatures, the flowering process is faster and the flowering period is shorter.