【作者】 陈荣珠；

【导师】 沈应柏； 罗晓芳；

【作者基本信息】 北京林业大学 ， 植物学， 2012， 硕士

【摘要】 连香树(Cercidiphyllum japonicum Sieb. et Zucc)为我国二级保护珍稀濒危植物,具有很高的科研、药用及观赏价值。目前,连香树较多采用扦插、嫁接及种子繁殖,但这些繁殖方法繁殖率低、繁殖周期长,远不能满足园林绿化及科研等的苗木需求。本文以连香树(Cercidiphyllum japonicum Sieb. et Zucc)种子为试验材料,测定了种子的生理指标并探究了温度、光照及化学试剂对种子发芽率的影响,筛选出最佳的种子发芽条件。所测的生理指标为：种子的千粒重为0.721g,自然条件下种子活力为42.44%；即使采用KT、GA3(?)(?)10%PEG等溶液提前浸泡种子,并在光照条件下培养时,其萌发率分别仅为37.12%、36.31%和31.01%,由此可见,当连香树以种子进行繁殖时发芽率偏低,推测可能原因是种子胚存在某种抑制物质从而导致后熟。为了提高连香树的快速繁殖能力,本实验中我们重点采用了植物组织培养技术来建立此种濒危植物的高效繁殖体系。以一年生带腋芽的茎段和种子苗的茎段为外植体,利用植物组织培养技术,建立并优化了连香树的离体再生体系。实验结论如下：获得无菌材料的最佳消毒方法为：先用70%的酒精消毒30s,再用0.1%的升汞消毒12min和6min,存活率分别为23.33%和22.22%；最佳的芽增殖配方为MS+6-BA1.0mg/L+NAA0.5mg/L+GA32.0mg/L+蔗糖30g/L+琼脂7g/L+pH6.0,增殖系数高达6.33；最佳的生根配方为1/2MS+IBA2.0mg/L+NAA0.5mg/L+6-BA0.5mg/L+AC2.0g/L+蔗糖30g/L+琼脂7g/L+pH6.0,生根率、根数及根分别为80%、5.5条和6.51cm；用高效液相色谱法测定了生根苗在生根培养过程中四种内源激素(IAA、ABA、CTK、GA3)的时间动态变化情况时,发现IAA的含量高于ABA、CTK、GA3的含量,IAA含量和IAA/ABA值是调控生根的主要因子,ABA、CTK、GA3含量与生根呈负相关；以茎段和叶片外植体时,为诱导愈伤组织的最佳培养基为MS+2,4-D2.0mg/L+6-BA0.1mg/L+蔗糖30g/L+琼脂7g/L+pH6.0+暗培养。更多还原

【Abstract】 Cercidiphyllum japonicum Sieb. et Zucc with high scientific research medicinal and ornamental values is a kind of precious and endangered plant of the national second-grade protection in China. In present, the propagations mostly are cottage breeding grafting and seed propagation. But, these propagations are low productivity and long multiplication cycle, while the quantity of plantlet is far from the needs of offorstation and scientific researches.In this paper, we tested the physiological indexes of seeds which were influenced by temperature light and chemical reagents to select the best codition of germination of Cercidiphyllum japonicum Sieb. et Zucc. The results of physiological indexes included that the1000-seed weight was0.721g and the the seed vigor was42.44%in natural condition. Although the seeds were soaked in the KT GA3and10%PEG solution ahead of time, the germinations were only37.12%36.31%and31.01%respectively. This showed that the embryo of the seeds having inhibitory substance to lead afterripening when lower production with seeds. To enhance the ability of rapid propogation of Cercidiphyllum japonicum Sieb. et Zucc, we used the technique of plant tissue culture and established rapid propogation system.We established and optimized the regeneration system with axillary buds and the stems of seeding seeds by using the technique of plant tissue culture. The resultes represented below:The best antiseptic method of asepetic materials was that the explants were sterilized with0.1%HgCl2for12min and6min.respectively after disinfected by70%etanol for30s, and the survival rates respectively reached23.33%and22.22%in1/2MS medium.The best proliferation medium of shoot clums is MS+6-BA1.0mg/L+NAA0.5mg/L+GA32.0mg/L+sugar30g/L+agar7g/L+pH6.0, with the highest multiplication rate of6.33. The optimized rooting culture medium is1/2MS+IBA2.0mg/L+NAA0.5mg/L+6-BA0.5mg/L+AC2.0g/L+sugar30g/L+agar7g/L+pH6.0, while the rooting rate root number and the root length is. respectively80%5.5and6.51cm. A positive correlation is found between rooting and the content of IAA and the value of IAA/ABA using high performance liquid chromatography in rooting culture The optium inducing callu medium by leaf and stem is MS+2,4-D2.0mg/L+6-BA0.1mg/L+sugar30g/L+agar7g/L+pH6.0, and the callus induction is61.11%and77.78%in darkness.更多还原