【作者】 郝晨；

【导师】 李云；

【作者基本信息】 北京林业大学 ， 林木遗传育种， 2006， 硕士

【摘要】 四倍体刺槐(Tetraploid Robinia pseudoacacia L．)是从韩国引进的人工诱变的大叶四倍体刺槐，具有速生、叶大肥厚、条粗、枝密、营养价值高，较强的抗逆性等十分优良的特性，是水土保持、发展畜牧业的优良品种。在我国的北方地区，四倍体刺槐可作为我国重要的多用途经济树种，是重要的造林先锋树种。 杂交育种技术是培育优良树木品种的有效方法，在主要经济树木育种中已得到广泛的应用。但四倍体刺槐的胚败育与低结实率现象非常严重，通过人工杂交得到的杂种胚更是因严重败育而难以获得杂种植株，因而其人工育种迄今仍属空白。因此，需要探索其败育机理、建立延缓胚败育及对早期幼胚进行抢救的方法和手段。 本论文对四倍体刺槐的大、小孢子发生和雌、雄配子体发育全过程进行细胞观察，以及对其相应时期的花芽形态相关性进行了研究，为今后进行栽培和育种方面的工作提供理论依据，为其胚胎学研究提供资料，也为花器离体培养提供科学依据。 胚胎学试验结果表明：四倍体刺槐花药壁发育为基本型，中层早期解体，绒毡层为腺质绒毡层，成熟绒毡层细胞为单核，小孢子母细胞减数分裂过程中，细胞质分裂为同时型，四分体多为正四面体型，少数为左右对称型，生殖细胞游离在营养细胞质内后，细胞壁消失。成熟花粉粒为2-细胞型，具三或四个萌发孔，表面具粗网状饰纹。孢原细胞向内分裂形成造孢细胞，其中只有一个发育成大孢子母细胞，大孢子母细胞产生不均等的二分体、线型或T型排列的四分体，合点端的为功能大孢子，胚囊发育为蓼型。两极核受精前融合或不融合，双珠被、厚珠心、弯生型胚珠，反足细胞早期退化，两个助细胞分别在受精前后退化，成熟胚囊为8核。 幼胚离体培养结果表明：在含有2，4-D2mg／L，6-BA1mg／L，CH300mg／L，的MS培养基上培养，幼胚胚性愈伤组织生长最好，形成的淡绿色的愈伤组织可以得到胚性愈伤组织。将这些愈伤组织转移到含有BA3.0mg／L+NAA0.5mg／L+KT3.0mg／L的MS培养基上培养可以形成不定芽。更多还原

【Abstract】 Tetraploid Black Locust was a quadruploid trees pecies from which a large-leaved and fast growing Black Locust introduced from South Korea was manned induced, which has such many excellent characteristics as fast growing, large leave, robust seedlings, excellent resistance entironmental restoration and biomass production. Black locust is a multipurpose legume tree species in our country and one of the important silviculture harbingers in northern region of our country.Crossbreeding as a effective way to cultivate excellent trees variety has been extensively applied on major economic trees breeding. Embryo abortion and Low seed seting percentage of Tetraploid Black Locust is very serious, and the result through hybridization is too serious to gain hybrid plant, so its artificial breeding remains blank up to now. Therefore it is necessary to expound the abortive mechanism, and to fend the method of puting of abortion and rescuing young embryo.In this paper, deals with the development of megaspore & microspore genesis and the formation of female& male gametophytes in Tetraploid Robinia psendoacacia. The characteristic of cytological development period of it’ s microspore and corresponding shape of flower bud and their interrelation were investigated. Therefore, this research aims at providing a theoretic basis for the culture and breeding, and in order to be applied to guide suitable data in it’ s embryology and the vitro culture of floral organ. The results of embryology were as follow:In addition, The anther is 4-sporangiateand its anther wall formation conforms to the dicotyledonous basical type. And also the two middle layers are ephemeral. The tapetum, of which each cell always remains uninucleate, is the secretory type. The cytokinesis after meiotic division of PMCs is simulataneous. Most microspore arrangement in the tetrad is tetrahedral, a few is obilateral. After the generative cell becomes free in the cytoplasm of the vegetative cell, its wall disappears. Besides, The mature pollen grains are binuclear with 3 or 4 apertures. They are triporate with thick netlike exine sculpture on their surfaces.The archesporial Cells cut off primary parietal cells and sporogenous cells, of which only one cell is functional. The megasport mother cell gives rise to unequal dyad and the linear tetrad. The chalazal megaspore in line type or T-type tetrad is functional. The development of embryo nary sac is of the polygonum type. The nuclear membranes of two polar nuclei fuse each other or don’t before fertilization.. The mature ovules are campylotropous with dual-integrment and crassinucellate. Three更多还原