滇鼠刺花的形态发生(鼠刺科)

在扫描电镜下,观察了滇鼠刺(Itea yunnanensis Franch.)花的形态发生.花3朵一束,排成总状花序.花器官为轮状结构,向心发生;花萼以2/5螺旋式相继发生,5个花瓣原基几乎同步地在花萼内侧与其互生的位置发生.雄蕊单轮对萼.当雄蕊发生后,花顶中心的分生组织开始凹陷,成为浅锅状;在其周围出现一个环状的分生组织,随之,2心皮原基产生,进而发育为马蹄形.初期的心皮相互分离,随着进一步发育,心皮内卷,彼此靠近、紧贴,逐渐于腹面合生,形成2室的中轴胎座;花柱的腹维管束通过薄壁组织连通;花期柱头融合,因此该种为合生心皮.对鼠刺属(Itea)及相关类群花发育性状和花结构进行了比较,支持把鼠刺属提升为鼠刺科(Iteaceae)的观点.     

西南美木滇鼠刺

滇鼠刺(Itea yunnanensis Franch.)为鼠刺科(也有学者主张将之归入虎耳草科)常绿灌木或小乔木,高1—10m,叶薄革质,卵形或椭圆形,长5—10cm,宽2.5—5cm,先端尖,边缘具锯齿;总状花序顶生,常俯弯至下垂,长达20cm。蒴果长约6mm,在每个菱形的蒴果内产有很多黑色的纺锤形细小种子。     

榛属（桦木科）花序及花的形态发生

在扫描电镜下观察了桦木科榛属榛、毛榛和滇榛的花序和花的形态发生过程。榛属雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基;每个花原基分化出2个心皮原基,形成二心皮雌蕊;雌蕊基部有2层花被原基,内层花被原基环状,外层花被发生于花原基近轴面和远轴面,近轴面和远轴面的花被不均等分化,外层花被发生早于内层花被。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成。每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出2枚次级苞片和4。6个雄蕊原基,形成4—6枚雄蕊,每个雄蕊具4个药囊,在雄蕊原基分化形成4药囊雄蕊过程中．出现雄蕊原基纵裂。并且花丝纵裂至基部。为进一步全面探讨桦木科属间系统演化关系提供了证据。     

华中五味子（五味子科）雄花和雌花的形态发生

通过扫描电镜观察了中国特有种华中五味子（ＳｃｈｉｓａｎｄｒａｓｐｈｅｎａｎｔｈｅｒａＲｅｈｄｅｔ．Ｗｉｌｓ）,雄花和雌花的形态发生过程,雄花：花被片和雄蕊连续向顶发生,未见有雌性结构的分化,花药的分化先花丝,雄蕊始终螺旋状排列在柱状花托上,雌花：花被片和心皮也为２／５序列连续地螺旋状向顶发生,未见有雄性结构的分化,心皮原基近轴面基部边缘的活动不明显,心皮为对折型：胚珠原基在心皮近轴面上近边缘处发生     

澜沧尧花（瑞香科）的花部形态发生及其系统学意义

通过扫描电镜对澜沧荛花Wikstroemia delavayi花部的形态发生过程进行了观察和分析,旨在为该属的系统学研究提供花部发育形态学资料.澜沧荛花花部的发生和早期发育呈远轴面向近轴面的顺序,但这一式样由于近轴面的器官在早期发育之后生长加速发生了转变.因此,花开放时所表现的所谓辐射对称,显然是由同一轮器官的异率生长所导致的次生现象.花盘发生于花萼筒基部的远轴面上,与花萼、雄蕊的发生间隔时间较长.花盘原基在下轮雄蕊着生处凹陷或间断,与之相对应,花盘裂片与下轮雄蕊呈互生.由此,花盘显然不是花托的一部分,也不是象花萼、雄蕊和心皮一样的独立结构,将其解释为雄蕊群的一部分更合理.花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性,这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有一定意义.根据对雌蕊群的发生和发育过程观察,该种的子房是由一个近轴面的可育心皮和一个远轴面的不育心皮融合而成的单室子房,为假单心皮雌蕊.尽管荛花属和瑞香属均属于单室子房,但澜沧荛花的子房维管束中的腹束排列于中轴位置,而目前资料显示瑞香属植物的腹束接近于侧膜位置,这方面仍需进一步研究.     

毛尾刺虫无性生殖周期中的形态和形态发生

利用蛋白银染色法研究了毛尾刺虫的形态及无性生殖周期中的形态发生,其过程为：（１）后仔虫口原基出现在左缘棘毛内侧深层,其内的毛基体组装成整齐排列的小膜并分化成新ＡＺＭ１,ＡＺＭ２和口侧膜,（２）前仔虫口原基出现在老仔虫ＡＺＭ２之前方深处,其随后发育成前仔虫的ＡＺＭ２口侧膜及ＡＺＭ１的一部分,并更新老结构的ＡＺＭ１中第７－１１片小膜,（３）额腹横棘毛原基为５列,分别以３：３：２：２：３方式分化最终产出     

单性木兰（木兰科）花的形态发生

报道了单性木兰(Kmeria septentrionalis Dandy)花的形态发生过程。发现过去一直被认为是雌花条状披针形的“内轮花被片”,实际为退化雄蕊,它形态发生的时间与位置均与雄花的雄蕊相同,在成熟结构中仍可见药室残迹,说明单性木兰的雌性花是由两性花退化而来。通过与K. duperreana(Pierre) Dandy和Magnolia thailandica Noot. &; Chalermglin雌花的比较,发现它们雌花的形态相同,从而得知人们长期以来对此3种植物雌花的认识有误,原一直认为的“内轮花被片”实为退化雄蕊。     

榛属 (桦木科) 花序及花的形态发生

在扫描电镜下观察了桦木科榛属榛、毛榛和滇榛的花序和花的形态发生过程。榛属雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基;每个花原基分化出2个心皮原基,形成二心皮雌蕊;雌蕊基部有2层花被原基,内层花被原基环状,外层花被发生于花原基近轴面和远轴面,近轴面和远轴面的花被不均等分化,外层花被发生早于内层花被。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成。每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出2枚次级苞片和4~6个雄蕊原基,形成4~6枚雄蕊,每个雄蕊具4个药囊,在雄蕊原基分化形成4药囊雄蕊过程中,出现雄蕊原基纵裂,并且花丝纵裂至基部。为进一步全面探讨桦木科属间系统演化关系提供了证据。     

鼠刺科鼠刺属一新种

Itea tenuinervia S. Y. Liu,sp.nov.Affinis I. riperiae Coll. et Hemsl. quaeplantisad 6 m altis,foliis obovato-oblongis,ellipticis vellanceolatis,racemo pendulo,pedicellis(3～ 5 mmlongis) etpetalis(4 mm longis) omnine brevioribusdiffert;etiam species I. tho…     

峨眉尖舌苣苔（苦苣苔科）花部形态发生及其系统学意义

观察了峨眉尖舌苣苔（Ｒｈｙｎｃｈｏｇｌｏｓｓｕｍｏｍｅｉｅｓｅ）花序及花的形态过程,并同近缘类群进行比较和分析,结论如下：１）峨眉大苣台花发生组织通常的总状花序分生组织已发生开变和位偏从而导致不平衡分化,形成花偏向于腹部一侧的变了形的总状花序,２）花冠和能育雄蕊的两侧性可能和退化雄蕊相关。３）该种雄蕊早期的发生和发育过程仍保持着祖先群群中轴肥座的系统发生式样,并在随后的发育过程中转变成侧膜胎座,４     

马先蒿属植物花冠分化与繁殖适应的研究进展

结合已有的研究报道和作者近年来的工作,对马先蒿属（Pedicularis）植物的花冠多样化成因与繁殖适应特性进行了总结和探讨。通过对该属4种进化花冠型的花器官发生和分化的研究发现,花部各器官在发生和发育初期基本一致,后期上唇形态的分化是导致成熟花形态结构产生较大差异的重要阶段。孢粉学研究认为,花冠类型与花粉萌发孔类型之间具有显著相关性;萌发沟的演化可能与繁殖适应有一定的关系。分子系统学研究表明,多样化的花冠类型在不同的谱系内经过若干次的独立进化而表现出了高度的平行演化（parallelism）。传粉生物学研究证实,该属植物花冠多样化与其主要传粉者熊蜂属（Bombus）昆虫的传粉行为存在较为密切的关系。具有相同（似）花冠类型的马先蒿可能被同种或不同种的熊蜂以相同的方式访问,但在花粉落置位置上存在显著差异,这可能有助于同域分布重叠的物种间在生殖上的机械隔离,而花冠的分化在一定程度上促进了新的物种形成。     

Floral morphogenesis in Euptelea (Eupteleaceae, Ranunculales)

BACKGROUND AND AIMS: Based on molecular phylogenetic studies, the unigeneric family Eupteleaceae has a prominent phylogenetic position at or near the base of Ranunculales, which, in turn, appear at the base of eudicots. The aim of the present paper is to reveal developmental features of the flowers and to put the genus in a morphological context with other basal eudicots. METHODS: Flowers in all developmental stages of Euptelea pleiosperma were collected in the wild at intervals of 7-10 d in the critical stages and studied with a scanning electron microscope. KEY RESULTS: Remnants of a perianth are lacking throughout flower development. Floral symmetry changes from monosymmetric to asymmetric to disymmetric during development. Asymmetry is expressed in that the sequence of stamen initiation is from the centre to both lateral sides on the adaxial side of the flower but starting from one lateral side and proceeding to the other on the abaxial side. Despite the pronounced floral disymmetry, a dimerous pattern of floral organs was not found. The carpel primordia arise between the already large stamens and alternate with them. Stamens and carpels each form a somewhat irregular whorl. The carpels are ascidiate from the beginning. The stigma differentiates as two crests along the ventral slit of the ovary. The few lateral ovules alternate with each other. CONCLUSIONS: Although the flowers have some unusual autapomorphies (wind pollination, lack of a perianth, pronounced disymmetry of the floral base, long connective protrusion, long temporal gap between androecium and gynoecium initiation, small space for carpel initiation), they show some plesiomorphies at the level of basal eudicots (free carpels, basifixed anthers, whorled phyllotaxis), and thus fit well in Ranunculales.     

商陆属植物的花器官发生

为进一步研究商陆科的系统位置提供花器官发生和发育的证据,在扫描电子显微镜下观察了商陆Phytolacca acinosa、多雄蕊商陆P. polyandra和垂序商陆P. americana的花器官发生.结果表明: 商陆属植物花被的发生均为2/5型螺旋发生.在同一个种不同的花蕾中,花被的发生有两种顺序:逆时针方向和顺时针方向.远轴侧非正中位的1枚先发生.雄蕊发生于环状分生组织.在单轮雄蕊的种中8-10枚雄蕊为近同时发生;两轮雄蕊的种8枚内轮雄蕊先发生,6-8枚外轮雄蕊随后发生,内轮雄蕊为同时发生,外轮雄蕊发生次序不规则.心皮原基也发生于环状分生组织,8-10枚心皮原基为同时发生.在后来的发育过程中,商陆的心皮发育成近离生心皮雌蕊;其他2种心皮侧壁联合发育成合生心皮雌蕊.对商陆属植物花器官发生的类型及发育形态学做了分析,结果支持商陆科在石竹目系统发育中处于原始地位的观点.     

Chaotic Floral Phyllotaxis and Reduced Perianth in Achlys (Berberidaceae)

Among the 16 genera of the Berberidaceae Achlys is the only one with a reduced perianth, an irregular floral phyllotaxis, and variable stamen number. Early floral stages show an unstable (chaotic) arrangement of the organ primordia. Only the single carpel of the gynoecium has a more fixed position in that the placenta is formed in the adaxial half of the flower. The irregularities in the androecium may be caused by the lack of influence of a perianth on floral symmetry. On the other hand, the regular orientation of the carpel is perhaps due to the early polarity of the flower, whereby the abaxial half of the flower is larger (with further developed stamen primordia) at the time when carpel polarity is established.     

极度濒危植物云南蓝果树的形态修订

极度濒危植物云南蓝果树(Nyssa yunnanensis)是雄性两性异株植物,其发表时仅根据雄花模式和果模式。作者通过野外观察和标本研究,发现目前对其雄花描述不全或不准确且缺乏两性花的描述,故本文修订了其雄花形态的原始描述,并且补充描述了其两性花和果实的形态特征。     

Floral ontogeny in ficinia and isolepis (cyperaceae), with focus on the nature and origin of the gynophore

BACKGROUND AND AIMS: The generic delimitations of Ficinia and Isolepis, sister genera in the Cypereae, are blurred. Typical Ficinia flowers have a lobed gynophore, which envelops the base of the nutlet, whereas in Isolepis the character is considered to be absent. Some former species of Isolepis, lacking the gynophore, were recently included in Ficinia. The floral ontogeny of representative taxa in Ficinia and Isolepis were investigated with the aim of evaluating the origin and nature of the gynophore in the Cypereae. METHODS: The spikelet and floral ontogeny in inflorescences collected in the field was investigated using scanning electron microscopy (SEM) and light microscopy (LM). KEY RESULTS: SEM images of Isolepis setacea and I. antarctica, Ficinia brevifolia, F. minutiflora, F. zeyheri and F. gracilis, and LM sections of F. radiata, show that the gynoecium in Ficinia is elevated above the flower receptacle by the development of a hypogynous stalk. From its apex, a (often three-)lobed cup is formed, which envelopes the basal part of the later nutlet. In developing flowers of I. antarctica, a rudimentary hypogynous stalk appears. In I. setacea, rudiments of a hypogynous stalk can be observed at maturity. In F. radiata and F. zeyheri, intralocular hairs are present in the micropylar zone. At the surface of developing gynoecia in flowers of F. gracilis, star-shaped cuticular structures appear which disappear again at maturity. CONCLUSIONS: The overall floral ontogeny of all species studied occurs following a typical scirpoid pattern, though no perianth primordia are formed. The gynophore in Ficinia originates as a hypogynous stalk, from which the typical gynophore lobes develop. The gynophore is not homologous with the perianth.     

台闽苣苔(苦苣苔科)花部器官的形态发生

在扫描电镜下对台闽苣苔 (T. oldhamii (Hemsl.) Solereder)进行了花部器官形态发生的观察,为探索该类群的个体发育、类群间的系统发育关系和进化趋势提供依据.研究发现该属植物萼片、花冠和雄蕊发生式样均为五数花类型,它们各自来源于花原基上分化出来的萼片原基、花冠原基和雄蕊原基;花冠与雄蕊的两侧对称性与花冠上唇生长稍快和退化雄蕊原基发育迟滞相关;萼片原基的发生和发育的顺序是不一致的:萼片原基发生的式样为近轴中原基-远轴2原基-2侧原基,发育式样则为近轴中萼片-2侧萼片-远轴2萼片,花蕾时为镊合状排列.花冠裂片原基的发生和发育式样是一致的,即远轴中裂原基(下唇中裂片)-远轴2侧裂原基(下唇2侧裂片)-近轴2裂原基(上唇2裂片).花蕾期卷迭式为覆瓦状排列,从外向内:下唇中裂片-下唇2侧裂片-上唇2裂片或下唇2侧裂片-上唇2裂片-下唇中裂片.雄蕊原基与花冠裂片原基互生,前方雄蕊原基在发生上稍迟于后方雄蕊原基,后者与退化雄蕊原基几乎同时发生,但较小,并与近轴心皮(或柱头上唇)对生.将该属与玄参科(Scrophulariaceae)的地黄属( Rehmannia )、苦苣苔科(Gesneriaceae)的异叶苣苔属( Whytockia)和尖舌苣苔属(Rhynchoglossum )的花部器官比较发现,这四个属在这方面呈现出多样性和交叉.过去一直按子房室数和胎座类型划分玄参科(子房2室、中轴胎座)和苦苣苔科(子房1室、侧膜胎座)这一做法受到了质疑.