【作者】 李永强；

【导师】 郭卫东； 陈文荣；

【作者基本信息】 浙江师范大学 ， 植物学， 2010， 硕士

【摘要】 中国樱桃(Prunus pseudocerasus Lindl.)作为我国重要的果树种类之一,但其相关的研究报导较少。花芽分化是果树由营养生长阶段向生殖阶段的转折,它是果树生命周期中至关重要的生命现象之一。休眠是多年生落叶果树抵御不良环境的一种有效过程。落叶果树满足低温需求量顺利地完成自然休眠是进行下一个生长发育循环所必须经历的重要阶段,休眠已成为限制果树设施栽培发展的制约因素,同时也限制了落叶果树向暖热带地区发展。樱桃的开花物候期早,花期易受低温危害,这是造成浙中地区樱桃产量低而不稳的主要原因之一。因此,在容易遭受倒春寒侵袭的地区,选择开花晚的品种进行露地栽培,以免造成不必要的损失。本论文研究了樱桃花芽的整个发育过程,包括花芽分化、休眠和萌发的问题。通过生理学和形态学的方法对浙江地区的中国樱桃花芽生理分化期和形态分化期进行界定。通过摘叶和生理指标的测定确定短柄樱桃09年花芽的生理分化期为7月5号至7月25号,花芽形态分化开始于7月下旬,整个分化时期可分为花蕾分化期、花萼分化期、花瓣分化期、雄蕊分化期及雌蕊分化期这5个时期,在7月15号以前尚未开始形态分化,花原基和苞片原基的分化最早出现在7月15号；花萼分化期集中在8月；花冠原基的分化此期一般从9月上旬开始,可延续到9月中旬。花芽进入花瓣分化期后,其分化进程加速,很快过渡到下一时期。雄蕊原基最早出现在9月上旬,10月上旬除一小部分的花芽处于雄蕊分化期,其余全部进入雌蕊分化期。整个分化时间约持续70 d左右。通过田间温度记录仪连续三年对短柄樱桃花芽需冷量和金华地区冬季低温积累量进行了统计研究。结果表明：短柄樱桃花芽自然状态下打破休眠是在12月的中下旬。通过三年数据的比较与分析,犹他模型的统计结果比0-7.2℃、≤7.2℃模型更稳定,估计短柄樱桃需冷量在300 C.U左右；统计结果同时显示金华地区冬季的冷温积累量可以达到1000 C.U左右。通过形态解剖研究浙江地区中国樱桃休眠过程中花器官发育情况,整个休眠期间,花芽的内部细胞通过分裂,扩大和分化导致了器官的形成。雄蕊原基的发育最为明显,发育至通过维管组织相连的四个小孢子囊的花药结构,在打破休眠时花药发育为小孢子母细胞阶段。相同夜温条件下,通过设置六个不同的昼温度处理,研究了不同温度对中国樱桃花芽萌发过程中花器官发育的影响。结果表明,温度对樱桃花芽萌发的形态解剖和生理有显著影响。温度越高,花芽发育越快,开花越早。在35/10℃处理条件下,绝大多数花芽到达花序可见期便停止生长,不能正常开花而脱落；30/10℃处理极显著地抑制了花冠、雄蕊及雌蕊的发育,花药不能正常开裂散粉。在进行温度处理前,花药已发育到小孢子母细胞阶段。昼温30℃以上处理15天,小孢子母细胞不能进行正常减数分裂而导致雄性败育。25/10℃处理能进行减数分裂,形成四分体,但形成的花粉粒部分败育。通过测定在六个温度处理下中国樱桃花芽中丙二醛(MDA)含量的变化,探讨了不同温度下膜脂过氧化作用的情况。35/10℃、30/10℃、25/10℃三个处理下,MDA含量均是在花序可见期后开始升高；20/10℃、15/10℃、10/10℃三个处理相对稳定。表明昼温高于25℃造成了膜脂过氧化伤害。对浙中山区主栽的3个中国樱桃品种‘短柄’、‘黑珍珠’、‘大鹰嘴’的开花物候期、花器官、果实性状进行了观察。结果表明：3个品种开花物侯期有明显差异,‘大鹰嘴’花期最早,‘短柄樱桃’最晚。不同品种的雌蕊长度和子房直径无显著差异,花瓣颜色、形状、花冠大小差异显著,花粉量也存在显著差异。花冠直径与单果重存在明显的相关关系。对短柄樱桃花粉萌发率、花粉管伸长速率进行研究表明蔗糖对于维持樱桃花粉外界环境渗透压作用很明显,添加适量的硼酸有利于离体花粉的萌发。当蔗糖的浓度为30 g/L、硼酸的浓度为3 g/L时短柄樱桃花粉内外的渗透压保持平衡,离体萌发率最高。通过温度试验表明,在25℃条件下花粉萌发率和花粉管伸长速率均达到最高,说明早春低温不利于中国樱桃花粉萌发,影响授粉受精。更多还原

【Abstract】 Chinese cherry(Prunus pseudocerasus Lindl.) is one of the important fruit tree species in South China, but has less research reports. Flower bud differentiation is the transition from the vegetative growth stage to the reproductive phase, and essential to the life cycle of fruit trees, which is one of the phenomenas of life. Dormancy is an effective process to resist adverse environment for perennial deciduous fruit trees. Deciduous fruit trees meet the chilling requirement and successfully complete dormancy is an important stage for the the next cycle of growth and development. Dormancy not only has become a limited factor for cultivation of fruit trees, but also limits the development of deciduous fruit trees cultivating to the warm tropical regions. The flowering phenology of cherry is early, and the phase of flowering is susceptible to the hazards of low temperature. This is one of the main reasons that the cherry productions are low and unstable. Therefore, the areas which vulnerable to be attacked by late spring coldness, we can select late flowering varieties in open field cultivation, so as to avoid unnecessary losses. This paper studied the whole process of development of the cherry flower bud, including the problems of flower bud differentiation, dormancy and germination.We defined the stage of physiological differentiation and morphological differentiation of the Chinese cherry flower buds in Zhejiang Province by the method of physiological and morphological. The period of physiological differentiation of Short-petiole cherry flower buds was defined in 2009 by picking off leaves and measuring physiological indicators, the results indicated that the phase started from July 5 to 25. Morphological differentiation began in late July. The whole process can be divided into the alabastrum differentiation stage, sepal primordial differentiation stage, petal primordial differentiation stage, and stamen and pistil primordial differentiation stage. Flower buds in a certain condition of non-differentiation., the stage of flower and bract primordia differentiation first appeared in the July 15. Most flower buds were found in the sepal primordial differentiation stage in August. The petal primordial differentiation started at the beginning of September, can be extended to mid-September after the petal primordial differentiation stage, the process accelerate, and soon translate to the next period. Stamen primordia differentiation first appeared in early September, all came into the pistil primordial differentiation stage except a small part of flower buds at stamen differentiation stage. The whole process approximately continues for 70 days.The chilling requirement of Short-Petiole Cherry and the accumulation of low temperature in Jinhua were calculated by temperature recorder during three years. The results showed that the time of dormancy breaking of Short-Petiole cherry flower bud under natural conditions is Sometime in December. Utah model results were more stable than 0-7.2℃,≤7.2℃models through analysing the three-year data; the chilling requirement of Short-Petiole cherry flower bud can reach about 300 C.U. The data also indicated that in Jinhua area, the chilling accumulation in winter was about 1000 C.U. The development of floral organs were researched during the process of dormancy. Cell division, enlargement, and differentiation, which lead to organogenesis, take place throughout the entire "dormancy" period. Stamen primordial develops to the structure of anthers which have four tetrasporangiates with the two locules in each of the two lobes being joined by connective tissue. In stage of dormancy breaking, anthers develop to the phase of pollen mother cells (PMC).Effect of temperatures on the development of flower organs of Cerasus pseudocerasus were examined at different day-temperatures (10-35℃) and the same night-temperature (10℃). The results showed that temperature significantly affected the morphology and physiology of flower buds. The higher the temperature, the earlier the flower buds developed and blossomed. In treatments with 35/10℃, the majority of flower buds was developmentally stopped at tight cluster stage and thus led to no flowering. In treatments with 30/10℃, development of flower, stamen and ovary was significantly inhibited and anthers did not normally dehisce. Paraffin section observation showed that anthers were developed to the microsporocyte stage before treatments with different temperatures. Fifteen days after treatments with the day-temperatures above 30℃, microsporocytes were stuck with tepetal cells and thus led to inhibition of normal meioses and stamen abortion. To investigate the status of membrane lipid peroxidation, contents of malondiadehyde (MDA) were detected in flower buds of Cerasus pseudocerasus treated with 6 different day-temperatures, respectively. The results showed that the contents of MDA increased after the stage of tight cluster in treatments with 35/10℃,30/10℃, and 25/10℃, respectively, whereas MDA levels were relatively stable in treatments with 20/10℃,15/10℃,10/10℃, respectively. This finding indicates that membrane lipid peroxidation damage was occurred at the day-temperature above 25℃.Characters of blossom phenophase, floral organs and fruits of three Chinese cherry cultivars,’Duan bing’,’Hei zhenzhu’,’Da yingzui’were observed in Zhejiang mountainous areas. The result showed that cultivars’the blossom phenophase greately differed among these cultivars,’Da yingzui’blossomed firstly,’Hei zhenzhu’latest. No significant difference was observed in pistil length and ovary diameter among the three cultivars. There were significant differences in petal color, shape, corolla size and Pollen quantity. A significant correlation was found between corolla diameter and fruit weight. Sucrose is important for the cherry pollen to maintain the external osmotic pressure. Pollen germination ratio、pollen tube elongation rate of Duan bing cherry were also studied. The results indicated the addtion of an appropriate amount of boric acid greatly benefited germination of vitro pollen. When concentration of sucrose was 30g/L, boric acid was 3g/L, inside and outside of’Duan bing’osmotic pressure comes to balance; the ratio of pollen germination under this condition was the highest. Temperature experiments showed that the temperature of 25℃was the optimal temperature for the pollen germination and pollen tube elongation rate. These results implied the fairly low temperature in the early spring was a obstacle for the pollen germination and pollination of Chinese cherry.更多还原