【作者】 周庆源；

【导师】 傅德志； 靳晓白；

【作者基本信息】 中国科学院研究生院（植物研究所） ， 植物学， 2005， 博士

【摘要】 最近的一系列分子系统发育分析一致认定睡莲目为3个最早的被子植物谱系(即包括Amborellaceae、睡莲目和一个由八角目、Trimeniaceae、Austrobaileyaceae组成的分支在内的ANITA)之一,这些研究结果和新近发现的早白垩世时期的睡莲类植物花化石的记录,支持过去长期认为睡莲目代表原始类群的观点。作为睡莲目组成之一的睡莲科,虽然在被子植物分类系统中一直处于关键的核心的系统发育位置,但对于这个科的生殖生物学和生殖形态学的研究还没有得到足够的重视。本文对睡莲科的王莲属、萍蓬草属和睡莲属的花的生物学、Nuphar microphylla的胚胎学、睡莲科的花粉形态学、睡莲科的胚珠和种子的发育形态学、以及睡莲科的柱头的形态解剖学开展了深入细致的研究工作。本文所研究的睡莲科植物的花都具有开花生物钟的特性,在开花时期花器官的开放和闭合呈现有规律的运动。睡莲科的有些种植物(如睡莲属的一些种)的花是白天开放晚上闭合,而另外一些种(如王莲属)的花却是晚上开放白天闭合。睡莲科的不同物种的花的开花天数不同,一般是2到数天。花大多是雌性先熟的,通常从开花的第二天开始释放花粉。睡莲科的不同属植物在开花时间,花的气味,花的颜色,各种花器官的形状和功能,以及传粉者方面存在很大差异。克鲁兹王莲的花具有大型的,单生的,多数花器官,花器官呈现有规律的开放和闭合运动,雌性先熟,能散发强烈气味,能够改变颜色,温度发生变化等特征。作者认为这些特征是高度特化的,它们适应于昆虫传粉。对Nuphar microphylla的花的生物学研究支持Lippok等人的观点:在任何居群,蝇、蜜蜂和甲虫对传粉贡献的相对大小更多地取决于这些昆虫的相对丰富度和可替换食物的多少,而不是取决于旧世界与新世界的萍蓬草属植物之间的雄蕊长度的差异。本研究首次在Nuphar microphylla中发现了一种新的4细胞5核雌配子体(具有1个卵细胞,2个助细胞和1个具有2个单倍体核的中央细胞)类型,这种雌配子体通过受精作用将产生三倍体的胚乳。作者认为这种雌配子体可能是最小的性功能单位,代表着被子植物的祖征。睡莲科是一个具有多形态花粉的科,花粉沟有远极单槽和环槽两种类型。当前研究建议萍蓬草属的远极单槽花粉在睡莲科中是最原始类型。花粉形态学研究支持睡莲科是一个原始类群的观点。更多还原

【Abstract】 The Nymphaeales were consistently identified by recent molecular phylogenetic analyses as one of the three earliest lineages of angiosperms (the ANITA clades: Amborellaceae, Nymphaeales, Illiciales, Trimeniaceae, and Austrobaileyaceae), which, together with the new record of fossils of water lily flowers from the Early Cretaceous, support the long-held view that the Nymphaeales represent a primitive taxon. The critical phylogenetic position of the Nymphaeaceae, which belong to the Nymphaeales, has not so far drawn much attention of researchers to the characters of reproductive biology and reproductive morphology that might represent plesiomorphies in the angiosperms evolution. The present studies carefully investigated the floral biology of Victoria, Nuphar and Nymphaea, the embryology of Nuphar microphylla, the pollen morphology of the Nymphaeaceae, the developmental morphology of the ovule and seed of the Nymphaeaceae, the morphology and anatomy of the stigma in the Nymphaeaeceae. The flowers of the Nymphaeaceae studied all show the phenomenon of biological clock. The regular opening and closing movements of the floral organs occur during anthesis. Some species are day-blooming, whilst the others are night-blooming. The flowers are mostly protogynous and they are open two to several days (depending on the species) with pollen release usually commencing on the second day of flowering. The different genera of the Nymphaeaceae exhibit considerable variation in the timing of flower opening, flower odor, flower color, the form and function of various flower parts and the preference of pollinators. Based on my studies on Victoria cruziana, it is suggested that the flowers of Victoria are highly specialized for and adapted to pollination by insects. My investigations on the floral biology of Nuphar microphylla support the contention of Lippok et al. that the relative contribution of flies, bees, and beetles to pollen transfer in any one population depends more on the relative abundance of these insects and alternative food sources than on stamen length differences between the Old World and New World pond lilies. Here I report in Nuphar microphylla a new pattern of four-celled/five-nucleate female gametophyte (with an egg cell, two synergids, and a central cell with two haploid nuclei). I speculate that this type of female gametophyte may be the minimal sexually functional size, and that it is likely to be plesiomorphic for flowering plants. The Nymphaeaceae is an eurypalynous family. Pollen aperture of this family can be divided into two types—anasulcus and zonasulculus. It is suggested that the anasulcate pollen of Nuphar represents the most primitive pollen type in the Nymphaeaceae. The view that the Nymphaeaceae is one of the most primitive angiospermous families is supported by pollen morphology. In all the species of the Nymphaeaceae examined, the inner integument arises as a ring, but the outer integument initiates as a semiannular outgrowth interrupted on the concave side of the funiculus, then the outer integument becomes hood-shaped. The outer integument is hood-shaped at early stages of ovule development, but becomes cup-shaped later in Nymphaea rubra, N. lotos, N. mexicana, Euryale ferox, and Victoria cruziana. It is suggested that the hood-shaped outer integument is primitive and the cup-shaped one is derived in Nymphaeaceae. The family is highly diverse in stigma type. The stigmatic surface in Nymphaea is covered with numerous crowded multicellular papillae. The stigma in Nuphar and Euryale is unicellular-papillate. The stigmatic surface appears bumpy in Victoria. Den Hartog’s hypothesis that Ondinea is closely related to Nymphaea is supported bystigma morphology.更多还原