为媒人开放的凤仙花

凤仙花是凤仙花科凤仙花属(Impatiens)植物的泛称,历来以其奇特而美丽的花吸引着人们的注意,我国民间广泛栽培的指甲花(I. balsamina)就是其中的一种。古时候的人们在化妆时常用它的花来染红指甲,指甲花因此而得名。指甲花的花为两性花,左右对称,萼片3枚,其中两枚侧萼片很小,另一枚大,花瓣状,称为唇瓣,舟形,基部具有一个长距,距的末端有蜜腺,可分泌蜜汁;花瓣5枚,上面一枚圆形的为旗瓣,两侧的为冀瓣,每个冀瓣两裂,是由两个侧生花瓣结合而成的,因此看上去一朵花只有3枚花瓣。指甲花代表了凤仙花属植物花的基本结构与形态,此类结构的花,能够高…     

毛舞花姜花器官的发生与发育

通过扫描电镜观察了毛舞花姜(Globba barthei Gagne p.)的花序及花器官的发生与发育。3枚萼片原基首先于花顶连续发生,随后花顶的中心凹陷形成环状原基,环状原基进一步分化形成三枚花瓣—雄蕊共同原基,并在花顶的中心形成花杯。共同原基分化形成花瓣和三枚内轮雄蕊,紧接着外轮雄蕊在花杯的顶点发生。远轴的两枚内轮雄蕊延伸生长并相互融合形成了唇瓣,近轴的一枚形成了可育雄蕊;近轴的两枚外轮雄蕊发育形成了成熟花结构中的侧生退化雄蕊,而远轴的一枚缺失。近轴的两枚外轮雄蕊原基起始的同时,3枚心皮原基也在中心花杯的内侧发生而后与外轮雄蕊相间排列。对毛舞花姜花序的发生和发育的观察发现,在花序轴的头几片初级苞片中产生的是珠芽原基而非蝎尾状小花序原基,其形态特征类似于早期的蝎尾状小花序原基,由此推测珠芽很可能是蝎尾状小花序的变异。     

掌叶木的花器官发生及其系统学意义

利用扫描电子显微镜和光学显微镜观察了掌叶木的花器官发生过程。观察结果表明: 花序原基最先发生, 然后形成两个大小不一的花原基; 萼片原基的发生不同步, 螺旋状向心发生; 4-5枚花瓣原基以接近轮状方式近同时发生; 不存在花瓣-雄蕊复合原基; 7-8枚雄蕊原基为近同时发生, 其生长较花瓣原基快; 心皮原基最后发生, 3枚心皮原基为同时发生。花为单性花。在雌花中, 子房膨大而雄蕊退化。在雄花中, 雄蕊正常发育, 子房退化。讨论了掌叶木花器官发生和发育的系统学意义。     

突脉金丝桃的花器官发生及其系统学意义

利用扫描电镜（SEM）观察了突脉金丝桃（Hypericum przewalskii）（金丝桃科）的花部器官发生发育过程。结果表明,突脉金丝桃2枚苞片原基首先发生,花原基在苞片原基的包裹中完成发育。在苞片原基发生后,5枚萼片原基沿2/5圆周依次发生。萼片原基发生近完成时,5枚雄蕊—花瓣共同原基在萼片原基之间的角隅处近同时发生,此后,雄蕊—花瓣共同原基下部向外伸展形成花瓣原基,上部向上凸起形成与花瓣原基相对的雄蕊原基,之后雄蕊原基由内向外依次分化发育产生次生雄蕊原基,随着次生雄蕊原基的发育和数目的增多,形成了5束雄蕊。次生雄蕊原基发生的同时,5枚心皮原基近同时发生。突脉金丝桃雄蕊束的发生方式表明,金丝桃属的雄蕊束可能起源于5基数的单轮雄蕊。金丝桃科与藤黄科植物花瓣及雄蕊原基发生方式的显著不同,支持了APG Ⅲ系统将金丝桃亚科从藤黄科中独立为金丝桃科的观点。     

单瓣与重瓣垂丝海棠花器官形态发育比较观察

为探究垂丝海棠重瓣花成花原因,该研究以单瓣垂丝海棠和重瓣垂丝海棠为实验材料,应用体式显微镜和扫描电镜观察垂丝海棠单瓣、重瓣品种花器官分化过程;解剖观察重瓣垂丝海棠大蕾期的花与盛开的花,统计其花器官的形态与数目;应用R语言对重瓣垂丝海棠的花瓣数目与其余各轮花器官数目进行相关性分析。结果显示：(1)单瓣和重瓣垂丝海棠的花器官分化均分为萼片原基分化期、花瓣原基分化期、雄蕊原基分化期、雌蕊原基分化期,且各轮花器官按照向心顺序依次分化发育。(2)在花瓣原基分化期,单瓣垂丝海棠仅分化出一轮(5枚)均匀分布于两枚萼片交汇处的花瓣原基,而重瓣垂丝海棠分化出两轮分布散列的花瓣原基,第一轮为5~7枚,第二轮为7~10枚。(3)在重瓣垂丝海棠各轮花器官中存在较多萼片瓣化、雄蕊瓣化、雌雄蕊异常发育的情况。(4)重瓣垂丝海棠各轮花器官数目间相关性分析结果显示,其花瓣数目与雄蕊数目以及瓣化中的雄蕊数目间存在明显的正相关关系,该现象与常规雄蕊瓣化植物表现的雄蕊数目减少、花瓣数目增多的现象不同。研究表明,重瓣垂丝海棠花瓣数目的增多并不完全依赖于雄蕊变瓣,暗示垂丝海棠重瓣花成花原因的多元性与复杂性。     

蓝堇草属(毛茛科)花形态发生的扫描电子显微镜观察

花的发生和发育过程研究可以发现早期进化的轨迹,为系统发育的研究提供重要线索。蓝堇草属(Leptopyrum)为毛茛科唐松草亚科一单种属,仅包含蓝堇草一种,其花的发生和发育过程仍为空白。为了深入理解唐松草亚科乃至毛茛科花发育多样性和演化规律,该文运用扫描电子显微镜(SEM)观察了蓝堇草各轮花器官的形态发生和发育过程。结果表明:该属植物所有的萼片、花瓣、雄蕊和雌蕊均为螺旋状发生,花器官排列式样也为螺旋状; 5枚萼片原基宽阔,5枚花瓣原基圆球形、位于萼片原基的间隔,且在后期表现为延迟发育现象,雄蕊原基较小、为圆球形;花瓣原基和雄蕊原基连续发生,无明显的时空间隔,但与萼片原基有时空间隔;心皮原基为马蹄形对折,柱头组织由单细胞乳突组成;胚珠倒生、具单珠被。该属花器官螺旋状排列、胚珠具单珠被在唐松草亚科中是独有的性状,花发育形态学证据支持了该属的特殊性。     

马先蒿属花冠无喙类的花器官发生

对花冠无喙类密穗马先蒿(Pedicularis densispica)和大王马先蒿(P．rex)的花器官电镜扫描发现,两种不同花冠型(无齿和具齿)的马先蒿花部器官发生和发育初期十分相似,表现为明显的单轴对称。2个萼片原基首先发生于花顶的近轴侧位,然后沿花顶边缘向远轴端发育形成--马蹄形结构。密穗马先蒿在近轴中部又出现1枚萼片原基,随后马蹄形结构分化出4枚萼片,并与近轴中部的原基愈合后构成5齿萼片;而大王马先蒿的2齿萼片直接由马蹄形结构发育而成。5枚独立的花瓣原基随后发生,但发育相对滞后;除近轴中部位置1枚空缺外,4枚雄蕊原基与花瓣原基位置呈交互发生;2个心皮原基同时在拱形花顶的近轴和远轴端发生,剩余的花顶形成中间的隔膜,并与2个心皮形成中轴胎座。对马先蒿与金鱼草(Antirrhinum majus)和毛地黄(Digitalis purpurea)花器官发生和发育初期的特征进行了比较,讨论了马先蒿属花冠对称性变化的意义。     

长喙毛茛泽泻的花器官发生

用扫描电镜对长喙毛茛泽泻的花器官发生进行了观察。该种的花器官发生在泽泻科中既典型又比较特殊。其特殊之处在于从花原基的发生直至最外轮６枚雄蕊原基的发生过程存在单向发育：３个萼片和原基和３个花瓣原基的发生存在次序性,萼片原基和花瓣原基均为顺时针发生,邻近花序侧生分支复合芽的萼片原基和花瓣原基倾向于优先发生;     

泽苔草的花器官发生

本文用扫描电镜观察了泽苔草的花器官发生过程,观察结果表明：花萼以螺旋状方式向心发生,花瓣以接近轮状方式近同时发生,不存在花瓣雄蕊复合原基。雄蕊和心皮均以轮状向心方式发生,6枚雄蕊分两轮分别在对萼和对瓣的位置先后发生,至发育的后期排成一轮,但仍分别处于对萼和对瓣的位置;随后发生的第一轮3个心皮原基与3枚萼片相对,第二、三轮心皮原基分别为1~3个,与前一轮心皮相间排列向心发生。本文首次揭示了泽苔草花被的外轮3个萼片螺旋状发生方式,这种螺旋状方式很可能是泽泻科植物的花部结构在进化过程中适应环境而保留下来的一种较原始的叶性特征。     

宽叶泽苔草的花器官发生

通过扫描电镜观察了宽叶泽苔草Caldesia grandisSamuel.的花器官发生。宽叶泽苔草 的萼片3枚,逆时针螺旋向心发生 ;花瓣3枚,呈一轮近同时发生,未观察到花瓣_雄蕊复合原基;雄蕊、心皮原基皆轮状向心 发生,最先近同时发生的6枚原基全部发育成雄蕊,随后发生的6枚原基早期并无差别,在发 育过程中逐渐出现形态差异,直至其中1－4枚发育成心皮,其余的发育成雄蕊;而后的几轮 心皮原基,6枚一轮,陆续向心相间发生。本文揭示了3枚萼片螺旋状的发生方式,并推测这种螺旋方式是泽泻科植物进化过程中保留下来     

Floral development in Impatiens chishuiensis (Balsaminaceae): formation of two well-developed anterolateral sepals and four carpels

Impatiens is a highly diversified genus with remarkable zygomorphic flowers. Floral ontogeny of three species of Impatiens has recently been studied, which suggested that, during the course of evolution, the anterolateral sepals become reduced and that these rudimentary sepals fuse postgenitally or congenitally with the anterior petal. All three belong to the majority type with five carpels and no mature anterolateral sepals. However, a few species of Impatiens have four carpels and two well-developed mature anterolateral sepals, and their floral development has never been examined. From a comparative-ontogenetic viewpoint, we explore the mechanism of formation of well-developed anterolateral sepals and four carpels in I. chishuiensis with five sepals and four carpels. The results show that, if anterolateral sepals are present, their early development statuses will likely influence whether or not the sepals can fully develop later, and that the initiation and development of five stamens have an effect on the shapes of floral apexes, eventually resulting in congenital fusion of two adaxial carpels. Furthermore, we discuss the systematic and evolutional value of floral early development data.     

A SCANNING ELECTRON MICROSCOPIC STUDY ON THE INITIATION AND DEVELOPMENT OF FLORAL ORGANS OF BRASSICA NAPUS (CV. WESTAR)

The initiation and development of the floral organs of Brassica napus L. (cv. Westar) were examined using the scanning electron microscope. After transition of the vegetative apex into an inflorescence apex, flower primordia were initiated in a helical phyllotactic pattern. The sequence of initiation of the floral organs in a flower bud was that of sepals, stamens, petals and gynoecium. Of the four sepal primordia, the abaxial was initiated first, followed by the two lateral and finally the adaxial primordium. The four long stamens were initiated simultaneously in positions alternating with the sepals. The two short stamens were initiated basipetal to and outside the long stamens, and opposite the lateral sepals. The petals arose on either side of the two short stamens and the gynoecium was produced from the remainder of the apex. During development, the sepal primordia curved sharply at the tips and tightly enclosed the other organs. Stamen primordia developed tetralobed anthers at an early stage while filament elongation occurred just prior to anthesis. A unique pattern of bulbous cells was present on the abaxial surface of the anther. Growth of petal primordia lagged relative to the other floral organs but expansion was rapid prior to anthesis. The gynoecium primordium was characterized by an invagination early in development. At maturity, there was differentiation of a papillate stigma, an elongated style and a long ovary marked externally by sutures and divided internally by a septum. Distinct patterns of cuticular thickenings were observed on the abaxial and adaxial surfaces of the petals and stamens and on the surface of the style. The patterns were less obvious on the sepals and ovary. Stomata were present on both surfaces of the mature sepals, on the style and restricted areas on the abaxial surface of the anthers and nectaries but were absent from the petals, the adaxial surface of the stamens and the ovary. No hairs were present on any of the floral organs.     

灌木铁线莲（毛茛科）花器官的发生与发育

用扫描电子显微镜（SEM）对铁线莲属（Clematis L.）植物灌木铁线莲(C. fruticosa Turcz.)花的形态发生和发育过程进行了观察。灌木铁线莲花原基形成后,4枚萼片以交互对生的方式首先发生,呈轮状排列。最早的4枚雄蕊原基在4枚萼片交接的位置上近螺旋状发生,此后,随着雄蕊原基的向心发生和数目不断增多,其发生的螺旋状序列逐渐明显。雄蕊原基发生后,在花原基顶端,心皮原基沿着雄蕊原基的发生序列呈螺旋状发生。本文结果支持在原始被子植物花中螺旋状排列和轮状排列同时存在的观点。此外,本文也进一步证实了花萼与苞片的同源性。     

驴蹄草属和金莲花属(毛茛科)花器官的形态发生及系统学意义

利用扫描电镜观察了驴蹄草Caltha palustris L.和川陕金莲花Trollius buddae Schipcz.花器官的发生和发育过程。结果显示:驴蹄草和川陕金莲花的所有花器官均螺旋状向心式发生、向心式发育,花器官的螺旋状发生方式在毛茛科Ranunculaceae可能是一种基本式样;苞片、萼片与其他花器官原基的形状明显不同,显示苞片、萼片与其他花器官在系统发生上有所不同;川陕金莲花的花瓣在早期延迟发育且基部具囊,花瓣的延迟发育在毛茛科具花瓣的属中非常普遍,而花瓣基部的囊类似于耧斗菜属Aquilegia一些植物;两个属雄蕊群一纵列雄蕊中的小孢子均向心式发育,这种发育方式在毛茛科可能为基本类型。两个属植物的心皮原基均为对折式,在发育过程中,驴蹄草心皮顶端沿腹缝线形成下延的柱头组织,川陕金莲花不形成明显的柱头组织。根据花形态发生和发育特点,并结合其他研究成果,认为这两个属不应当属于同一个族。     

Floral morphogenesis of Caltha and Trollius (Ranunculaceae) and its systematic significance

The floral morphogenesis of Caltha palustris L. and Trollius buddae Schipcz. was observed with a scanning electron microscope (SEM). The primordia of all floral organs initiate spirally and centripetally and develop centripetally. The spiral initiation sequence may be a basic pattern in Ranunculaceae. The primordia of bracts, sepals, and other floral organs are different in shape: the bract primordia are triangle, the sepal primordia crescent, and the petal (in Trollius), stamen, and carpel primordia hemispheric. This may indicate that the bracts, the sepals and other floral organs are different in origin. The petals are retarded in early developmental stages in Trollius buddae Schipcz, and have purses at the base. The retarded petals are very common in Ranunculaceae and the purse of the petal is similar to that of some Aquilegia species. The microspores in a longitudinal series of stamens develop centripetally in Caltha and Trollius; this may be a basic pattern in Ranunculaceae. The carpel primordia are plicate. In the developmental process of the carpels, the stigmatic tissue appears from the apex of the style and is decurrent along the ventral suture in Caltha, but there is no obvious stigmatic tissue in Trollius. Based on floral morphogenesis characteristics as well as the results from molecular systematics, comparative morphology and palynology studies, we consider that Caltha is not closely related to Trollius and that these two genera should not be treated in the same tribe.     

Impatiens maculifera sp. nov. (Balsaminaceae) Yunnan,China

Impatiens (Balsaminaceae) is a notoriously difficult genus to study for reasons that include small, remote and endemic areas of occurrence, and difficulty in obtaining well‐dried herbarium specimens and separating and reconstructing floral parts from available dried specimens. Impatiens has also been notoriously difficult when it comes to phylogenetic resolution at the infrageneric level, but a new system with two subgenera (Impatiens and Clavicarpa) was recently proposed by Yu et al. and it has made it easier to classify newly discovered species. Impatiens maculifera, a new species of Balsaminaceae from Malipo County, Yunnan, China described here, is similar to I. parvisepala S.X. Yu & Y.T. Hou in having racemose inflorescences, four lateral sepals, clavate capsules and ellipsoid seeds, but differs in having leaves narrowly oval or with elliptic–lanceolate blades (versus obovate or obovate–lanceolate), obvious petioles (versus leaves subsessile), racemose inflorescence with 8–12 flowers (versus 6–8 flowers), flowers greenish yellow (versus yellow), lateral united petals and lower sepal with dense red spots (versus red spots absent), and dorsal petal with apparent stalk at base (versus unapparent stalk). Morphological characters and molecular phylogenetic analyses of DNA sequences from both nuclear ribosomal and plastid genes show that the new species differs distinctively from I. parvisepala. Furthermore, I. maculifera is distinguished from other Impatiens species based on morphological, micromorphological and palynological evidence, and molecular data.     

Impatiens pterocaulis sp. nov. (Balsaminaceae) from Guangxi,China

Impatiens pterocaulis S. X. Yu et L. R. Zhang, a new species of the Balsaminaceae from Yancha, Longlin, Guangxi Region, is described and illustrated. This species is similar to I. wilsonii in having nearly white flowers, 4 lateral sepals and a racememos inflorescence, but differs by having winged stems, very short‐spurred lower sepal, yellowish flowers and an acuminate dorsal petal apex. Pollen characters and leaf epidermal micro‐characters of these two species were studied, and the results support that the two species should be kept separate.     

Inflorescence and floral development of Dahlstedtia species (Leguminosae: Papilionoideae: Millettieae)

Inflorescence and floral development of two tropical legume trees, Dahlstedtia pinnata and Dahlstedtia pentaphylla, occurring in the Atlantic Forest of south-eastern and southern Brazil, were investigated and compared with other papilionoids. Few studies have been made of floral development in tribe Millettieae, and this paper is intended to fill that gap in our knowledge. Dahlstedtia species have an unusual inflorescence type among legumes, the pseudoraceme, which comprises axillary units of three or more flowers, each with a subtending bract. Each flower exhibits a pair of opposite bracteoles. The order of flower initiation is acropetal; inception of the floral organs is as follows: sepals (5), petals (5), carpel (1) plus outer stamens (5) and finally inner stamens (5). Organ initiation in sepal, petal and inner stamen whorls is unidirectional; the carpel cleft is adaxial. The vexillum originates from a tubular-shaped primordium in mid-development and is larger than other petals at maturity, covering the keels. The filament tube develops later after initiation of inner-stamen primordia. Floral development in Dahlstedtia is almost always similar to other papilionoids, especially species of Phaseoleae and Sophoreae. But one important difference is the precocious ovule initiation (open carpel with ovules) in Dahlstedtia, the third citation of this phenomenon for papilionoids. No suppression, organ loss or anomalies occur in the order of primordia initiation or structure. Infra-generic differences in the first stages of ontogeny are rare; however, different species of Dahlstedtia are distinguished by the differing distribution pattern of secretory cavities in the flower.