【作者】 樊莉丽；

【导师】 彭方仁；

【作者基本信息】 南京林业大学 ， 森林培育， 2012， 博士

【摘要】 本文以连云港后云台山国家森林公园内人工栽植的楸树（Catalpa bungei C.A. Meyer）为材料，首次对其有性生殖过程和繁育系统特征进行了较为系统的研究。分别从个体、种群和环境角度，分析该地区楸树自然不结实的原因，并重点对其自交不亲和性进行了组织形态学观察，主要结论如下：1.楸树花器官分化顺序为：花萼→雄蕊→花冠→雌蕊。药壁发育为双子叶型，具异型腺质绒毡层，小孢子母细胞减数分裂为同时型，四合花粉，二细胞型，无萌发孔。雌蕊2心皮合生，胚珠多数、倒生、单珠被、薄珠心，胚囊发育为单胞蓼型。杂交种胚发育类型为十字花型，合子休眠期内发生位移，约20d后分裂；胚乳具典型吸器结构。2.花芽分化、大小孢子和雌雄配子发育均正常，自交不育并非由雄性或雌性不育引起，而是由自交不亲和性所致。楸树自交花粉管在雌蕊不同部位均有抑制表现，以柱头和子房内抑制程度最深，花粉管最终停止生长的部位是子房，时间在合子形成前，为合子前晚期自交不亲和类型。3.楸树繁育系统属异交为主的混合交配类型，具有自交不亲和性，并有向自交演化的倾向。花部形态具典型虫媒花传粉综合征。开花类型为大量花爆发式开放型。种群盛花期持续时间长，个体间开花同步性强。4.该地区楸树自然不结实的根本原因是：楸树本身的自交不亲和性，以及由种群构成、传粉模式、和环境因素引发的花粉受限。更多还原

【Abstract】 The breeding system and sexual reproduction process of cultivated Catalpa bungei C. A.Meyer in Yuntaishan National Forest Park in Lianyungang City were investigated for the firsttime. The reason for its barrenness was analyzed from aspects of individual, population andenvironment, and histological observation was performed for characterizing its self-incompatibil-ity. The main results are concluded as follows:1. The differentiation procedure of flower organs in C. bungei were as follows: sepal formation,stamen formation, petal formation, and pistil formation. The development of anther wall wasclassified as dicotyledonous, and the tapetum was of glandular heterotypic. Meiotic divisions inmicrospore mother cells were followed by smiultaneous cytokinesis and resulted in tetrahedraltetrad. The mature pollen grains were2-celled and nonaperturate. The species showed superiorovary,2-locules, and axial placenta with many ovules. The ovule was anatropous, unitegmic andtenuinucellatae. The development of embryo sac was of polygonum type, and hybrid embryo wascruciferous type. Zygote displacement occurred during the dormancy, and division taken place atabout20days after pollination. Endosperm was cellular and eventually developed intohaustorium cell with typical structure in both mycropyle and chalazal.2. The processes of flower bud differentiation, microsporogenesis, and megasporogenesis werenormal. It shows that male or female sterility wasn’t the reason for barrenness happened in C.bungei. Self-sterility happened in C. bungei caused by its self-incompatibility. Self pollen tubeswere inhibited at different parts of pistil, especially in the stigma and ovary. The site of pollentube incompatibility reactions taken place was in the ovary, and the time was pre-zygotic, whichindicates the occurrence of pre-zygotic late-acting self-incompatibility in C. bungei.3. The breeding system of C. bungei was self-incompatibility, predominantly outcrossing butmixed with selfing, and the likely evolutionary tendency was from outcrossing to selfing. Theflower was entomogamy type whith typical entomophilous pollination syndrome. Blossom was“mass-flowering blomming” pattern. The full-bloom stage lasted for a long time in the populatio-n, and blossoms were synchronized between individuals.4. It is concluded that one reason for barrenness of C.bungei in Yuntaishan National ForestPark in Lianyungang City is self-incompatibility happened in the individuals, and the other ispollen-limitation caused by population composition, pollination models, and environmentalfactors.更多还原