【作者】 周楠楠；

【导师】 方炎明；

【作者基本信息】 南京林业大学 ， 植物学， 2010， 硕士

【摘要】 红桤木(Alnus rubra)具有广泛的应用前景和商业价值,已在我国江苏及周边地区引种成功。以南京六合的红桤木为试验材料,本论文观察和测定了红桤木的花粉形态和花粉生活力及贮藏特性,系统地研究了红桤木花芽分化、雌雄配子体形成、双受精和胚胎发育等有性生殖的完整过程,以期为桤木属的杂交育种和红桤木的进一步推广提供理论依据,也为桦木科花粉及胚胎学研究积累资料。主要结果如下：(1)花粉具显著的孔室,多为4-5孔,孔与孔之间有带状加厚,属桦木型。红桤木生态适应幅度广,可以在中国进行较大面积推广。(2)用TTC染色法和离体培养法对其生活力进行了测定,同时探讨了不同贮藏方法和解冻温度对花粉生活力的影响。结果表明：TTC法不适于红桤木花粉生活力的测定；花粉在10%蔗糖+0.1%硼酸的培养基上培养8h后萌发率最高；随着贮藏时间的延长花粉生活力下降,适宜贮藏温度为-20℃；超低温保存后,花粉以自来水冲洗解冻效果最好,但超低温保存并没有延长花粉保存时间。(3)雌、雄花葇荑状,其小花序外被1枚初级苞片和2枚次级苞片、2枚三级苞片,先形成的2枚次级苞片和后形成的2枚三级苞片均来源于小花序原基,位于中间的花原基比两侧的分化要早。雌、雄花发育进程表现出不同步性,传粉与受精间隔期约为2个月。(4)胚胎学特征：腺质绒毡层,倒生胚珠,单珠被,厚珠心,线型或“T”型大孢子四分体,蓼型胚囊,核型胚乳,多孢原细胞,最终发育为一个胚囊,极个别为两个胚囊,合点端大孢子为功能型大孢子。(5)花粉败育、胚囊败育、胚胎发生过程中胚囊萎缩退化等原因可能是红桤木结实率低的原因。更多还原

【Abstract】 Red alder (Alnus rubra) has broad application prospects and commercial values, it has been successfully introducted to Jiangsu Province and its surrounding areas in China. In this paper, we observed and measured pollen morphology, pollen viability and storage characteristics of red alder based the material from Luhe, Nanjing. The whole process of sexual reproduction e.g. differentiation of flower buds, formation of male and female gametophytes, double fertilization and embryonic development, were also comprehensively studied. We expect to provide a theoretical basis for breeding practice of Alnus and further promote of red alder and also accumulate data for pollen and embryo studies of Betulaceae. The main conclusions are as follows:(1) The pollen of red alder belongs to birch-type with clear apertures and mostly 4-5 inaperturate, there were belt thickening between inaperturates. Red alder had a wide range of ecological adaptation, so it is feasible to spread it in large area of china.(2) Pollen viabilities of red alder were tested by TTC staining and in vitro culture methods. The effects of different storage methods and different thawed temperatures on the germination of pollen were also investigated. The results showed that TTC method was not suitable for determination of red alder pollen; The rate of pollen germinate reached the highest after incubated for 8h on the media supplemented with 10% sucrose and 0.1% boric acid. Pollen viability decreased with the extension of storage time. The-20℃was a better temperature for red alder pollen storage. Through tap water was the best method for pollen thawed in cryopreservation, but pollen storage time was not extended under cryopreservation condition.(3) Female and male inflorescences were amentiferous. Each cymelet had one primary bract, two secondary bracts and two tertiary bracts. The two secondary bracts developed earlier than the two tertiary ones, all were originated from cymelet primordia. Female and male flowers developmental process showed a lack of synchronization, and pollination and fertilization interval was about two months.(4)Embryonic characteristics:glandular tapetum, anatropous ovules, single integument, thick nucellar, linear or "T"-type megaspore tetrad, polygonum-type embryo sac, nuclear-type endosperm, multiple archesporia and eventually developed into a embryo sac, a very few with two embryo sacs, chalazal end as the functional megaspore.(5) The low rates of seed sets in red alder may be caused by pollen abortion, embryo sac abortion and embryo sac shrinkage occurring in the process of embryogenesis.更多还原