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1.
莲科系统学和遗传多样性研究现状   总被引:1,自引:0,他引:1  
分析回顾了莲科的系统位置、莲品种分类的现状与问题和莲的遗传多样性。莲科(Nelumbonaceae)植物传统上被归入睡莲科(Nymphaeaceae)。许多研究表明,莲科与睡莲科在形态、细胞、孢粉等方面差异很大,因而建立莲科,置于睡莲目(Nymphaeales)、毛茛目(Ranunculales)或莲目(Nelumbonales)中。分子系统学研究发现,睡莲科为被子植物的基部类群之一,而莲科则是真双子叶植物的基部类群之一,与山龙眼科和悬铃木科有密切关系。莲科含莲(Ndumbo nucifera)和美洲黄莲(N.lutea)两种,间断分布于太平洋的两岸。莲在我国有悠久的栽培历史和广大的栽培面积,栽培品种超过600个。由于杂交和反复回交的原因,品种之间的遗传关系非常复杂。莲的遗传资源的研究还很不充分,尤其是野生类型。对一些栽培品种的研究其实验材料又含有美洲黄莲的遗传组分,因而多高估了莲的遗传多样性。  相似文献   

2.
睡莲目的数量分支分类学研究   总被引:1,自引:0,他引:1  
本文应用数量分支分类学的Farris-Wagner方法,研究了睡莲目10个已知属的系统发育关系。结果表明,唾莲目可分为3个科:莲科、睡莲科和金鱼藻科。本文还讨论了数量分支分析在植物分类学中的应用问题。  相似文献   

3.
睡莲科三属植物叶的比较解剖学研究   总被引:3,自引:0,他引:3  
报道了睡莲科的睡莲属、莼菜属和萍蓬草属三属植物叶的比较解剖学特征。结果表明,莼菜属叶柄仅具一个维管束,其余二个属均有数个维管束,且维管束为有限的、星散排列,这一特征与单子叶植物的很相似;叶柄基本组织中,除萍蓬草属无气道外,其它两个属均有气道;在睡莲属和萍蓬草属中存在星状石细胞,而莼菜属中则无此细胞;莼菜属和萍蓬草属具腺毛,睡莲属无腺毛。由于睡莲科此三属植物叶的解剖学特点存在很大的差异,因此认为睡莲科的这三属可能来源于不同的祖先,因此建议将莼菜属和萍蓬草属从睡莲科中分离出来。分别独立为莼菜科和萍蓬草科。  相似文献   

4.
睡莲科的核型分析及其分类学位置的探讨   总被引:5,自引:0,他引:5  
本文对睡莲科6属6种代表植物的核型进行了研究,并探讨了它的分类学位置。结果如下:莲2n=16=9sm+4m+3st;王莲2n=24=8sm+8m+8T,蓝睡莲2n=28,可配成14对,染色体小,第l号染色体上有2条随体;萍蓬草2n=34=18m+16sm;芡实2n=58,可配成29对,染色体小,第l号染色体有2条随体,莼菜2n=72,可配成36对,染色体按大小可分成大,中、小三个类别。除莲外,其它5种植物的核型为首次报道。莼菜的体细胞染色体数目2n=72和国外报道的2n=80不相一致。莲的染色体以及形态学特征和其它睡莲科分类群显著不同,可将其从睡莲科中独立出来,并成立莲科和莲目。原归属于睡莲科的分类群仍组成睡莲目,并分别置于莼菜科和睡莲科。  相似文献   

5.
睡莲科叶比较解剖   总被引:11,自引:2,他引:9       下载免费PDF全文
本文报道了睡莲科6个种比较解剖学的研究结果。莼菜的叶柄具一对维管束,其它5个种为 有限的、星散排列维管束,它们与单子叶植物相似;叶柄基本组织中除萍蓬草无气道外,其它种均有。叶为两面叶页,毛茛型气孔局限分布于叶腹面,但莲叶背面亦发育有少量气孔。莲的气孔在发育时属单唇型,成熟时则呈毛茛型。排水器、厚壁异细胞只见于莲。腺毛及吸水器除莲外,供研究的其它种在叶背面均存在。除莼菜及莲外,其它种都有星状石细胞。 根据本文的观察结果,我们认为莼菜属是睡莲科中较简化的属,它和Cabomba属有密切的亲缘关系,它们可独立成莼菜科(Cabombaceae),包括于睡莲目内。睡莲属、 萍蓬草属、芡属和王莲属(Victoria)彼此亲缘关系密切,可留于睡莲科。莲属具独特的形态,与睡莲科的其它属亲缘关系不甚密切,因此,不但可分立为莲科,而且可独立成莲目。  相似文献   

6.
睡莲科的系统发育:核糖体DNA ITS区序列证据   总被引:13,自引:1,他引:12       下载免费PDF全文
以金鱼藻Ceratophyllum demersum为外类群,使用PAUP4.0b4A软件对睡莲科Nymphaeaceae植物7属11个代表种的ITS区序列进行了系统发育分析。采用最大简约法分析获得了3个最简约树,步长为1125,一致性指数(CI)和维持性指数(RI)值分别为0.7618和0.7214。利用3个最简约树获取严格一致树。结果表明:(1)莲属Nelumbo位于系统树的基部,自展支持率为100%,可从睡莲科中独立出来成立莲科Nelumbonaceae和莲目Nelumbonales;(2)萍蓬草属Nuphar是一单系类群,位于分支Ⅱ的基部,并和睡莲科其他属(不包括莲属)植物聚在一起构成姐妹群,故萍蓬草属仍应置于睡莲科中;(3)水盾草属Cabomba和莼菜属Brasenia聚成一小支并构成姐妹群,自展支持率为99%,说明这两属之间亲缘关系较近;(4)睡莲属和芡实属Euryale、王莲属Victoria聚成一小支并构成姐妹群,自展支持率为94%,说明三者亲缘关系较近,仍应置于睡莲科中。  相似文献   

7.
《植物杂志》2012,(2):18-23
热带亚热带植物展览温室建于1965年,总面积1820平方米,以收集、保存、研究和展示热带、亚热带植物资源为目标,是开展植物多样性迁地保护和科学普及教育的重要场所。目前已收集展示棕榈科、仙人掌和多肉植物、蕨类植物、天南星科、兰科、凤梨科、百合科、山茶科、睡莲科等植物1100余种(含变种、  相似文献   

8.
睡莲科在被子植物中地位比较特殊,形态上复杂、多样,是系统研究的重要材料之一。一直以来,该科的解剖学上无导管的特征倍受关注。基于APG分类系统,对睡莲科的6个属的管状分子研究的现状做介绍和比较,并就其中存在的问题做了分析,指出过渡态导管需要统一的判断标准;而睡莲科的管状分子有必要做进一步的研究。  相似文献   

9.
莲属(Nelumbo Adans.)的系统学研究进展和莲科的确立   总被引:1,自引:0,他引:1  
本文介绍了莲属的系统学研究的历史和最新研究成果.综述了莲属从睡莲科中独立出来,单独成科的形态学、解剖学、细胞学、孢粉学、胚胎学、植物化学、分子生物学及花器官发生等多方面的证据,并对莲科的系统学地位进行了总结。  相似文献   

10.
荷花与莲     
正荷花与睡莲同为水生植物,因两者的叶及花的形态相似,不仅普通人经常无法识别,还长期被经典分类学家归为同一科——睡莲科。但随着后来形态学及分子生物学研究的不断深入,证明莲属植物与睡莲属存在巨大区别,应从睡莲科中独立出来,成为莲科。荷花同睡莲的主要识别特征在于:前者为挺水植物,立叶及花均高高伸出水面,叶片不开裂;后者为浮水植物,叶片及花浮于或略高水面,叶片均有一半径深度V字开口或裂缝。最简单的办法判断,睡莲的叶片肯定有开口,  相似文献   

11.
Phylogenetic systematics of the nymphaeales   总被引:2,自引:0,他引:2  
A cladistic analysis was applied to reveal the phylogenetic relationships among the Nymphaeales. Seventeen out of twenty three characters in gross morphology, anatomy and palynology were analyzed, for their evolutionary polarities. From the results of the present analysis, the phylogenetic status of each genus and their relationships were clarified: 1)Nelumbo is a distinct taxon and is presumed to have originated from an ancestral stock of the Nymphaeales; 2)Ceratophyllum has a close phylogenetic relationship withCabomba; and 3) in the Nymphaeaceaesensu stricto, Nuphar and the remaining genral constitute a monophyletic group. A conclusion obtained from the present analysis was that the following three families should be recognized in the Nymphaeales; Nelumbonaceae Nymphaeaceae, and Ceratophyllaceae. The generaBrasenia andCabomba are traditionally classified in the Nymphaeaceae or in the independent family Cabombaceae. However, they should be included in the family Ceratophyllaceae.  相似文献   

12.
Observations have been made on the pollination ecology of Cabomba caroliniana Gray in Texas. Flowers are trimerous with morphologically similar perianth parts. The adaxial corolla spurs are nectariferous and attract small Diptera (e.g. Notiphila cressoni and Hydrellia bilobifera). Anthesis occurs for 2 consecutive days with flowers opening about 10:00 a.m. and closing around 4 p.m. on each day. First-day flowers have short, indehiscent stamens and longer pollen-receptive stigmata which arch outward over the nectaries. In 2nd-day flowers the stamens have elongated to the level of the stigmata and extrorse dehiscense occurs above the nectaries. Stigmata of 2nd-day flowers are pressed together at the center of the flower and are nonreceptive to pollen. Insects attracted to 2nd-day flowers in search of nectar become dusted with pollen (due to the position and extrorse dehiscence of the anthers) and as insects fly to 1st-day flowers, achieve cross-pollination by virtue of the stigmata position over the nectaries. Seed anatomy is similar to that of other nymphaeaceous genera (i.e., abundant perisperm, little cellular endosperm, a haustorial nucellar “tube,” and a small dicotyledonous embryo). Pollination morphology and comparative xylem anatomy support the segregation of Cabomba from the Nymphaeaceae, sensu stricto. The anatomical correlations between seeds and the myophilous pollination syndrome (found elsewhere in Nymphaeaceae, sensu lato), however, suggest a phyletic relationship.  相似文献   

13.
Pit membranes of stem tracheids of all recognized species of Barclaya, an Indomalaysian genus of Nymphaeaceae, were studied with scanning electron microscopy (SEM). Pit membranes of the tracheids are composed of two thick layers, both constructed of fibrils much larger than those of tracheary elements of angiosperms other than Nymphaeaceae. The outer (distal) layer, which comprises the continuous primary wall around the tracheids, is spongiform, perforated by porosities of relatively uniform size, and confined to or most prominent on end walls of stem tracheids. The second layer consists of thick widely spaced fibrils that are oriented axially and are laid down proximally (facing the cell lumen) to the first (outer) layer, although continuous with it. These axial fibrils are attached at their ends to the pit cavities. This peculiar microstructure is not known outside Nymphaeaceae except in Brasenia and Cabomba (Cabombaceae, Nymphaeales), and has not been previously described for Barclaya. The longitudinally oriented threads and strands in perforation plates of secondary xylem of wood and stems of a variety of primitive woody angiosperms (e.g., Illicium) are not homologous to the pit membrane structure observed in stem tracheids of Barclaya, which, like other Nymphaeaceae, has only primary xylem and no perforation plates. The tracheid microstructure reported here is different from pit structures observed in any other group of vascular plants, living or fossil. The tracheid stem microstructures of Barclaya and other Nymphaeaceae appear to be a synapomorphy of Nymphaeaceae and Cabombaceae, and need further study with respect to ultrastructure and function.  相似文献   

14.
The examination of the primary xylem of roots of Nelumbo has revealed the presence of vessel elements with intra-face, transversely-rowed to obliquely-rowed bordered pitted side walls and scalariformly perforated end walls. Whole mounts of macerated xylem, serial sections of roots, and cells through which a water suspension of India ink particles under slight or no pressure was passed, were the means of investigation. It is our opinion that this discovery does not support theories which derive monocotyledons from the Nymphaeaceae. A discussion leading to this conclusion is presented.  相似文献   

15.
Geraniin, an antimicrobial hydrolyzable tannin against fish pathogenic bacteria, was isolated from Nymphaea tetragona (Nymphaeaceae).  相似文献   

16.
形态学研究显示睡莲科Nymphaeaceae具有许多原始性状。睡莲科又被称为“古草本”。最新的分子系统发育研究显示,睡莲科是现存被子植物系统树根部附近最早分异谱系的演化支之一,对研究被子植物(有花植物)的起源与早期进化具有重要价值,但有关睡莲科的范围和系统位置存在争议。被子植物的起源与辐射一直是植物学家关注的热点。本文对该科系统位置的研究历史与现状进行了评述。  相似文献   

17.
A host race is a population that is partially reproductively isolated from other conspecific populations as a direct consequence of adaptation to a specific host. The initial step in host race formation is the establishment of genetically based polymorphisms in, for example, morphology, preference, or performance. In this study we investigated whether polymorphisms observed in Galerucella nymphaeae have a genetic component. Galerucella nymphaeae, the water lily leaf beetle, is a herbivore which feeds and oviposits on the plant hosts Nuphar lutea and Nymphaea alba (both Nymphaeaceae) and Rumex hydrolapathum and Polygonum amphibium (both Polygonaceae). A full reciprocal crossing scheme (16 crosses, each replicated 10 times) and subsequent transplantation of 1,001 egg clutches revealed a genetic basis for differences in body length and mandibular width. The heritability value of these traits, based on midparent-offspring regression, ranged between 0.53 and 0.83 for the different diets. Offspring from Nymphaeaceae parents were on average 12% larger and had on average 18% larger mandibles than offspring from Polygonaceae parents. Furthermore, highly significant correlations were found between feeding preference of the offspring and the feeding preference of their parents. Finally, two fitness components were measured: development time and survival. Development time was influenced by diet, survival both by cross type and diet, the latter of which suggest adaptation of the beetles. This suggestion is strengthened by a highly significant cross x diet interaction effect for development time as well as for survival, which is generally believed to indicate local adaptation. Although no absolute genetic incompatibility among putative host races was observed, survival of the between-host family offspring, on each diet separately, was lower than the survival of the within-host family offspring on that particular host. Survival of offspring of two Nymphaeaceae parents was about two times higher on Nymphaeaceae than on Polygonaceae, whereas survival of offspring of two Polygonaceae parents was 11 times higher on Polygonaceae than on Nymphaeaceae (based on untransformed data). Based on these results, we conclude that genetically determined polymorphisms in morphology and feeding preference exist in G. nymphaeae, resulting in differential performance. Furthermore, in each diet separately, offspring of between-host family crosses were less fit than offspring of within-host family crosses. These results support the hypothesis that within this species two host races can be distinguished.  相似文献   

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