【作者】 姜金仲；

【导师】 李云；

【作者基本信息】 北京林业大学 ， 林木遗传育种， 2009， 博士

【摘要】 四倍体刺槐(Tetraploidy Robinia pseudoacacia)是由人工诱导二倍体刺槐(2X)体细胞加倍(4X)而育成(具有植物同源四倍体的生物学属性),是水土保持、防风固沙、改良土壤、营造饲料型灌木林的优良树种;为了奠定四倍体刺槐进一步遗传改良基础及揭示染色体同源加倍对四倍体刺槐花器官、种子发育及成熟表现型的影响,对四倍体刺槐花器官、种子的发育与变异进行了为期5年的系统研究,主要研究内容及结论如下。利用扫描电镜、石蜡切片及田间观察等方法观察分析了四倍体刺槐的花序发育进程、小花花器原基的分化进程、雄配子发育进程、雌配子发育进程及胚珠的发育进程,结果表明,四倍体刺槐各个花器官发育进程中的主要大环节和二倍体刺槐是一致的,但发育时间均有不同程度的滞后、一些发育细节上表现出不同程度的不稳定性。初步探索了四倍体刺槐胚珠败育规律及其与内源激素的关系。利用上述方法及TTC染色法对四倍体刺槐花序及花器的形态、结构、育性与开花授粉习性进行了研究。与二倍体刺槐相比:四倍体刺槐花器官的形态普遍表现出了巨大性变异;花粉及胚珠的育性均有不程度的降低;二倍体刺槐有一定异花授粉的可能性,四倍体刺槐则为严格的自花授粉。四倍体刺槐无性群体中不同个体之间及同一个体不同花序及小花之间,在花序形态,小花着生方式及结构方面均表现出了明显的性状不稳定性变异。利用解剖、生理生化指标测定、流式细胞仪、形态及重量分类等方法研究了四倍体刺槐种子及种子胚变异。染色体同源加倍使四倍体刺槐种子单粒重、有胚率和萌发率明显降低;四倍体刺槐不同重量级别的种子在种子解剖结构、有胚率、白色胚率及萌发率等方面表现出极大的差异;二倍体刺槐种子胚、胚乳及种皮重量接近等比,四倍体刺槐种子三者的比例严重失调。四倍体刺槐种子胚按照子叶数量、颜色及饱满程度,可以划分出5个类型,不同类型种子胚在可溶性蛋白含量、过氧化物酶活性、生命力、组织培养特性及平均重量方面明显不同。染色体同源加倍对四倍体刺槐花器及种子发育大环节影响不大,但能引起其形态、结构、育性及生理生化活性发生明显变异,这种变异具有一定的遗传改良意义。四倍体刺槐种子经温汤浸种或5-氮杂胞苷浸种,可以提高萌发率;初步探索了如何利用四倍体刺槐种子培养、成熟胚或幼胚培养等促萌措施、最大限度地保存四倍体刺槐有性过程中创造的变异资源。综合利用上述促萌措施,已得到四倍体刺槐一年生实生苗300株,二年生实生苗15株,3年生实生苗4株。更多还原

【Abstract】 Tetraploidy(4X)Robinia pseudoacacia(TRP) is bred by doubling diploid(2X) R pseudoacacia(DRP) (thereby it belong to autotetraploid).And it is a fine tree species used for conserving water and soil,.checking winds,fixing drifting sand,improving soil and construting shrubbery for fodder.To further improve genetically TRP and reveal autotetrapliod-biological property of development and variation of floral organ and seed from TRP, the development and variation have been researched for 5 years and the research contents and main conclusions are as follows.By scanning electron microscop,paraffin section,field obaervation and TTC staining methods,the development of inflorescence,floret anlage,male and female and ovule were studied and so were mophology, structure,fertility,flowering and pollination habit of inflorescence and flower organs forTRP.The key links in above developments are consistent with ones of DRP but accompanied by development hysteresis in different degrees.The inflorescens mophology,attachment and structure of florets show obvious trait-instability variation among individuals in TRP clone stand,inflorescences and florets on same individual.In virtue of dissecting,determinating index of physiology and biochemistry,flow cytometry,classifying based on mophology and weight,the variations of seed and seed-embryo were researched. Chromosome-homologically-doubling make individual seed weight,embryo rate of seed and germinating rate of TRP reduce obviously.There are huge variations with seed instruture,embryo rate of seed,white embryo rate and germinating rate of seed among different weitht-sorts seed of TRP.According to amount,color and plump degree of cotyledon,the seed embryo of TRP can be divided into 5 classes and the soluble protein content,peroxydase activity,vitality,tissue cultural character vary among different seed embryo types of TRP.Hot water and 5-azaC treatment can promote germination of seed of TRP,by which 300 one- years-old seedlings,15 two-years-old seedlings and 4 three-years-old seedling have been developed.更多还原