【作者】 李冬梅；

【导师】 赖钟雄； 潘东明；

【作者基本信息】 福建农林大学 ， 果树学， 2003， 硕士

【摘要】 本研究以龙眼“红核子”、“十二月龙眼”等品种胚性愈伤组织诱导出的小子叶形体胚为材料，采用石蜡切片、蛋白质电泳、可溶性糖和淀粉含量测定等手段，研究了光照条件、蔗糖浓度、PEG、ABA、椰乳等因素对龙眼体胚成熟的影响，以探讨龙眼体胚成熟机理。主要研究结果如下： 一、比较了光照、蔗糖浓度、PEG、ABA、椰乳等因素对龙眼体胚成熟的影响。黑暗和高浓度蔗糖(5％)有利于龙眼体胚的成熟，经过75d的“成熟培养”，体胚增大明显，白色，结实；椰乳对龙眼体胚成熟有利；光照、低糖、PEG、ABA均不利于龙眼体胚的成熟。 二、龙眼体胚经历黑暗和高浓度蔗糖(5％)的正常成熟过程，其体胚在细胞形态学上有共性，在体胚成熟过程中可见到明显的子叶和胚芽原基形成，生长点的细胞排列紧密，染色较深，富含淀粉粒；光照、低糖、PEG、ABA条件下成熟的体胚即使在成熟初期阶段能观察到子叶和芽原基，但到成熟后期时子叶断裂，胚芽原基消失，且细胞结构松散，染色较深的细胞较少。 三、龙眼体胚成熟过程和每个成熟阶段都可检测到特异蛋白质。在黑暗低糖和ABA同时作用下，龙眼体胚成熟过程中蛋白质合成最活跃，可检测到的蛋白质组分最多，蛋白质分子量变化范围最大，且大部分都在10～30KD之间；PEG作用下体胚成熟过程中蛋白质合成受阻，可检测到的蛋白质组分最少。 四、在高浓度蔗糖(5％)的作用下，龙眼体胚成熟过程各阶段总糖、果糖、蔗糖含量变化呈双峰型，而没有高糖作用的体胚成熟过程中可溶性糖含量的变化呈单峰型。龙眼体胚经过正常成熟后能够高频率萌发似乎与其可溶性总糖、蔗糖积累有关。 五、在光照低糖、光照高糖、黑暗低糖和PEG的作用下，龙眼体胚成熟过程中淀粉含量变化相似，整个成熟过程中淀粉含量变化呈单峰型；黑暗低糖、黑暗低糖和ABA、黑暗高糖和ABA、黑暗高糖和椰乳的作用下，龙眼体胚成熟过程中淀粉含量变化呈双峰型。而在黑暗和高浓度蔗糖(5％)作用下经历正常成熟的体胚，3个供试材料中淀粉含量变化也很相似，淀粉含量总的趋势都是上升。更多还原

【Abstract】 In this experiment the mechanism of the somatic embryo maturation was studied using small cotyledonary embryos induced from embryogenic calli(EC) in Dimocarpus longan Lour. cvs. "Honghezi" and " Shieryuelongyan " . The effects of light, sucrose concentration, PEG, ABA and coconut milk on the maturation of somatic embryos were compared through the observation of optical microscope of paraffin section, the analyses of specific proteins by SDS-PAGE and the examination of soluble sugars and starches. The main results were described as follows:1. The effects of light, sucrose concentration, PEG, ABA and coconut milk on the maturation culture of somatic embryos were compared. High concentration of sucrose (5%) in the dark was beneficial to somatic embryo maturation, and somatic embryos became bigger, white and compacted after maturation culture for 75 days. Coconut milk was also beneficial to somatic embryo maturation . Light, low concentration of sucrose in darkness, PEG, ABA were not suitable for somatic embryo maturation.2. The histomorphological characteristics of somatic embryos matured on the condition of high concentration of sucrose (5%)in the dark were similar, and the distinct cotyledons and blastic primodia were observed during somatic embryo maturation; moreover, the cells of the growth point arranged closely, dyed deeply and contained many starch grains. Although the formation of the cotyledons and blastic primodia were observed at the early stage of somatic embryo maturation on the conditions of light, low concentration of sugar, ABA, PEG, the cotyledons broke, the blastic primodia disappeared, and the cell construction was loose and with few cells dyed deeply during the latter period of maturation.3. Specific proteins were examined at the tested stages of somatic embryo maturation. In the treatment supplemented with low concentration of sucrose (2%) and ABA in darkness, the synthesis of the proteins was the most active, the components of the proteins examined were the most, the ranges of the proteins molecular weight were the widest, and most of them were between 10 KD and 30 KD.The synthesis of the proteins was inhibited in the treatment with low concentration of sucrose (2%) and PEG in darkness, and the components of the proteins examined were the fewest.4. There existed 2 peaks in the changes of the contents of the total soluble sugars, fructose, sucrose in the treatments with high concentration of sucrose (5%), while only 1 peak in the treatments without high concentration of sucrose. Somatic embryos could germinate at high frequency after normal maturation of high concentration of sucrose, which apparently have relation with their accumulation of the total soluble sugars and sucrose.5. In the treatments with low concentration of sucrose (2%) in the light, high concentration of sucrose (5%) in the light, or low concentration of sucrose (2%) and PEG in darkness, the changes of the starch contents were similar, and there existed only 1 peak during somatic embryo maturation, while 2 peaks in the treatments with low concentration of sucrose (2%) in darkness, low concentration of sucrose (2%) and ABA in darkness, high concentration of sucrose (5%) and ABA in darkness, high concentration of sucrose (5%) and coconut milk(5%) in darkness. In the treatments supplemented with 5% sucrose in darkness, the changes of the starch contents of "Honghezi I", "Honghezi II" and "Shieryuelongyan" embryoids were also similar with the ascending trend.更多还原