台闽苣苔（苦苣苔科）幼苗的发育式样及其意义

为解决台闽苣苔族 (Titanotricheae)这一单种族的科级系统位置 ,通过扫描电镜观察了台闽苣苔 (Titan otrichumoldhamii (Hemsl.)Solereder)植物的种子发芽和幼苗发育过程。随着下胚轴的向下伸长 ,两个子叶开始不明显的异率生长 ,其中一片子叶略大于另一片子叶。但两片子叶均正常发育并位于同一高度。当真叶发出后 ,两片子叶几乎等大 ,并且两个子叶柄等长。在幼苗生长期间 ,随着子叶的生长 ,胚芽也正常萌发出茎的顶芽。顶芽持续进行顶端生长产生交互对生的真叶。这一幼苗生长式样和苦苣苔亚科其他类群的仅一片子叶发育与胚芽被抑制的幼苗生长式样有明显区别。考虑到台闽苣苔植物在总状花序的上部大量簇生无性珠芽 ,并落地迅速生长出新的植株这一在苦苣苔科中独特的无性繁殖方式及相关性状 ,台闽苣苔族可能较早地从苦苣苔亚科中分化出来 ,并在繁殖体的功能进化方面和其他类群发生歧化进而获得独特的无性繁殖方式。台闽苣苔族在系统发育上应该被认为是其他苦苣苔亚科类群的姊妹群 ,应当提升为亚科等级。     

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.     

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 (Scrophulari aceae)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     

异叶苣苔属（苦苣苔科）雌蕊的畸形发育及其系统意义

异叶苣苔属（苦苣苔科）雌蕊的畸形发育及其系统意义王印政潘开玉李振宇洪德元（中国科学院植物研究所系统与进化植物学开放研究实验室,北京１０００９３）ＡＮＡＮＡＭＯＲＰＨＯＳＩＳＯＦＧＹＮＯＥＣＩＵＭＩＮＷＨＹＴＯＣＫＩＡ（ＧＥＳＮＥＲＩＡＣＥＡＥ）...     

广西苦苣苔科一新属——文采苣苔属

描述了在广西发现的苦苣苔科一新属和一新种,即文采苣苔属Wentsaiboea D. Fang & D. H. Qin及文采苣苔W. renifolia D. Fang & D. H. Qin, 并提供墨线图。文采苣苔属的柱头外形略似长檐苣苔属Dolicholoma D. Fang & W. T. Wang, 不同在于前者叶肾形,基部心形,具掌状脉,花冠斜钟状,裂片圆形,雄蕊和退化雄蕊着生于冠筒近基部。新属在体态上还接近小花苣苔属Chiritopsis W. T. Wang, 但前者叶具掌状脉,冠筒钟状,远轴侧膨胀,柱头马蹄形;在后者叶具羽状脉,冠筒筒状,不膨胀,柱头下唇倒梯形至线形。     

广西苦苣苔科一新属——方鼎苣苔属

报道了在中国广西发现的苦苣苔科一新属即方鼎苣苔属Paralagarosolen Y. G. Wei 和一新种方鼎苣苔P. fangianum Y. G. Wei。方鼎苣苔属与细筒苣苔属Lagarosolen W. T. Wang近缘,它们的共同特征是花筒细筒状,不肿胀,柱头2;不同点是方鼎苣苔属叶基部有时盾状,聚伞花序具1朵花,花冠裂片顶端圆钝,蒴果宽卵状椭圆球形。     

中国喜鹊苣苔属(苦苣苔科)一新记录种——雷氏喜鹊苣苔

报道了中国苦苣苔科(Gesneriaceae)喜鹊苣苔属(Ornithoboea Parish ex C.B.Clarke)一新记录种——雷氏喜鹊苣苔(O.lacei Craib),该种与滇桂喜鹊苣苔(O.wildeana Craib)近似,其区别特征在于花冠下唇裂片顶端凹陷,退化雄蕊3。凭证标本存放于广西植物研究所标本馆(IBK)。     

中国广西蛛毛苣苔属(苦苣苔科)一新种——桂林蛛毛苣苔

描述了采自中国广西的苦苣苔科新种桂林蛛毛苣苔Paraboea guilinensis L. Xu & Y. G. Wei。新种体态及叶形接近厚叶蛛毛苣苔P. crassifolia (Hemsl.) Burtt,与后者不同在于叶革质,花序梗、花梗及花萼均无毛,花冠明显二唇形,蒴果不旋扭。     

贵州金盏苣苔属(苦苣苔科)一新种——万山金盏苣苔

报道了贵州金盏苣苔属Isometrum一新种,即万山金盏苣苔I.wanshanenseS.Z.He。该种以花序梗、花梗被褐色长柔毛至近无毛,花冠细筒状,紫色,喉部不缢缩,上唇稍长于下唇,雄蕊及雌蕊均无毛而与柔毛金盏苣苔I.villosumK.Y.Pan相近缘,但叶具柄,柄长0.4–1.4cm,叶片较小,倒披针形,长1.5–4×0.5–1.6cm,聚伞花序具1–4朵花,花萼裂片外面近无毛或近顶端疏被褐色长柔毛,花柱与子房近等长而不同。     

广西半蒴苣苔属(苦苣苔科)一新变种——翅茎半蒴苣苔

记载了广西苦苣苔科一新变种——翅茎半蒴苣苔Hemiboea subcapitata Clarke var. pterocaulis Z. Y. Li。该变种与原变种不同在于茎具翅,花期较早。     

Patterns and Significance of Floral Development in Whytockia (Gesneriaceae)

Abstract: The floral development of Whytockia W. W. Smith has been studied in order to explore the developmental basis for the arrangement and differentiation patterns of floral organs, and the evolutionary relationship between Whytockia and allies in floral development. The descending imbricate aestivations in both calyx and corolla have remarkably different ontogenetic patterns between calyx and corolla which are derivative with respect to the development of the valvate aestivations in the four-stamened Rhynchoglossum. Both corolla lobes and stamens are initiated simultaneously from the same ring meristem. However, the five stamens remarkably precede the initiation of the five corolla lobes. Also, the adaxial stamen is suppressed after initiation to become a staminode, concomitant with retardation of its adjacent organs during development. This situation, together with the non-acropetal order among whorls of floral organs in Whytockia, is possibly related to a late expression and a remarkably different expression pattern of cycloidea- like genes as compared to Antirrhinum. Furthermore, the axile placentation in the bilocular ovary of Whytockia is formed by an involute closure of carpels rather than derived from a secondary fusion of two intrusive parietal placentae.     

新分类系统下长蒴苣苔亚科(苦苣苔科)细胞学研究概述

在最新分类系统框架下对长蒴苣苔亚科(Didymocarpoideae)的染色体资料进行了详细的整理和分析,结果表明,长蒴苣苔亚科的细胞学研究仍存在不足,尤其在种级水平上的研究不足25%,且存在一些属的染色体数据空白的现象。在新的分类系统下,一些修订后的属染色体数目表现出一致性或更加具有合理性,但也存在一些属的染色体数目变异仍十分复杂,如汉克苣苔属(Henckelia)和长蒴苣苔属(Didymocarpus)。基于已有的染色体数据,对长蒴苣苔亚科内一些重要属的染色体进化模式及其对物种分化的影响进行了探讨,推测染色体数目的多倍化及非整倍化进化可能对各类群的物种分化具有重要作用,但需要今后利用基于DNA探针的荧光原位杂交技术并结合分子系统学和基因组学研究才能深入地解析染色体的进化模式及其对物种分化的影响。     

Inflorescence development of Whytockia (Epithemateae, Gesneriaceae) and phylogenetic implications within Gesneriaceae

 The inflorescence development in Whytockia has been studied in order to explore the developmental basis for inflorescence architecture. The developmental pattern of the pair-flowered cyme in Whytockia basically conforms to that of most members in Gesneriaceae. However, the additional flower beside the terminal one in Whytockia is not equivalent to the frontal flower as in other Gesneriaceae because the former is located in the front-lateral position while the latter is in the front-median position. Also, the zigzag monochasial branching system in Whytockia represents the consecutive front-lateral branches rather than the lateral branches as in other Gesneriaceae. The inflorescence in Whytockia is flowering in a basipetal sequence, and its seemingly acropetal flowering sequence is due to the vigorous development of the consecutive front-lateral branches. In addition, the inflorescence of Whytockia does not represent the basic unit of the inflorescence in Epithemateae, and it is derived as compared to that of Rhynchoglossum. The development relationships of the inflorescence between Whytockia and its allies in Epithemateae are discussed on the basis of developmental and comparative evidence. Received February 15, 2002; accepted September 17, 2002 Published online: December 11, 2002     

Reversal versus specialization in floral morphological evolution in Petrocosmea (Gesneriaceae)

A widely held hypothesis in evolution is that adaptive specialization constrains the potential direction of future evolutionary change and thus may be irreversible, also known as Dollo's law. However, this hypothesis has long been subject to debate in evolutionary biology. Floral specialization is intriguing as it is usually linked to reproductive isolation and could affect speciation. Here, following the discovery of four new taxa, we observed some interesting phenomena of reversal versus specialization in morphology in a clade with the most specialized flowers in the genus Petrocosmea. In the phylogenetic tree based on sequences of multiple DNA regions, the morphological reversals, especially the regain of a long corolla tube, are nested within the branches characteristic of normally specialized flowers with a short corolla tube and highly specialized zygomorphy. Our results indicate that the highly specialized floral organ of this clade is still actively evolving in multiple branches toward specialization while reversals to different ancestral states occur in some branches. Great disturbance of ecological environment is likely a crucial factor affecting trait reversibility, such as the rapid uplift of the Himalayan–Tibetan plateau. The four new taxa are treated herein taxonomically. The flowers of this clade represent an interesting model to explore the genetic basis underlying the evolutionary reversal versus specialization and the interplay between genetic factors and environmental variables.     

苦苣苔科大叶石上莲CYC类基因RT-PCR表达模式研究

CYC类基因的分子系统学研究已经在苦苣苔科Gesneriaceae中展开,但是还缺乏对这些基因表达和功能的研究。因此,我们选择苦苣苔科大叶石上莲Oreocharis benthamii作为实验材料,分离出了CYC类基因的两个拷贝,经过分子系统学分析这两个基因分别属于苦苣苔科GCYC1和GCYC2两个分支,故命名为ObCYC1和ObCYC2。分区的RT-PCR实验结果显示这两个基因拥有不同的时间空间表达模式。ObCYC1与模式植物金鱼草Antirrhinum majus中的CYC基因类似,集中在花冠背部区域表达,这与它们拥有保守的功能区TCP和R相一致。但是,ObCYC1与CYC表达模式仍有区别,即,和CYC相比ObCYC1在花冠背部区域的表达提前减弱。这可能和大叶石上莲花冠微弱的两侧对称性相关。另外,由于大叶石上莲的背部花瓣较两侧和腹部花瓣小,因此,在功能上ObCYC1可能起抑制背部花瓣生长作用而CYC基因则促进背部花瓣生长。与ObCYC1不同,ObCYC2的保守功能区有更多的氨基酸位点变化,而且在RT-PCR实验中也没有检测到它的表达。因此,需要开展更深入的实验研究分析ObCYC2的基本功能,这将有助于了解GCYC2类基因在苦苣苔科及其近缘科中的功能和进化途径。     

Further chemical constituents from Sinningia canescens and S. leucotricha (Gesneriaceae)

Four new compounds were isolated from the tubers of Sinningia canescens and S. leucotricha: one naphthoquinone, 7-methoxy-8-hydroxy-α-dunnione (1); two arylbenzofurans, sinningial A (2) and B (3); and one sesquiterpene, 11-epi-subergorgiol (4). Seventeen additional known compounds were isolated and identified. The structures of all compounds were determined by spectroscopic and MS analysis.     

Taxonomy of the Genus Oreocharis (Gesneriaceae)

The genus Oreocharis as circumscribed here consists of 27 species including 5 varieties, of which 5 species and 4 varieties are described as new in the present paper. In the work analysed were the external morphology and geographic distribution and examined under SEM were pollen exine of 22 species and seed coat of 16 species. As a result, three types of the corolla, two types of the anther, three types of the pollen exine and three types of the seed coat are distinguished here in the paper. It is discovered that the corolla in the genus is relatively stable, though diverse, and highly correlated with the characters of pollen grains and seeds. The corolla clearly bilabiate but constricted at the throat, occurring in O. auricula, O. cordatula, O. aurantiaca, etc., for an example, is correlated with smooth, reticulate pollen exine and partial tectum and the reticulate and smooth seed coat. For this reason the subdivision of the genus in the paper is mainly based on the characters of the corolla, but combined with those of the anther, pollen and seed coat. The genus is divided into four sections in the present classification. Dasydesmus Craib, based on a single species. O. bodinieri, is reduced here, and the reasons are given. The genus is distributed mainly in the subtropics, and less frequently in the tropics, of China south of 32.5°N and east of 98.5°E, with only two species beyond the border, O. hirsuta in Thailand (only a single locality in Chiengmai) and O. aurea also found in north Vietnam (see Fig. 1, Table 3). Sect. 1. Stomactin (Clarke) Fritsch. Corolla urceolate-tubular, constricted at the throat, with limb distinctly bilabiate; anthers broad-oblong; seed coat reticulate, smooth, rarely minutely tuberculate; pollen exine fine-reticulate, tectum partial and smooth, luminae slightly unequal in size. Sect. 2. Orthanthera K. Y. Pan Corolla campanulate or campanulate-tubular; anthers broad-oblong; seed coat reticulate, muri smooth, rarely spiny-processed; pollen exine fine-reticulate, with partial and smooth tectum and luminae slightly unequal in size, rarely exine insular and fine-tuberculate, tectum perforate. Setc. 3. Oreocharis Corolla thin-tubular; anthers broad-oblong; seed coat densely spinyprocessed, rarely fine-tuberculate; pollen exine insular, densely spiny-processed, rarely finereticulate and smooth, luminae unequal in size. Sect. 4. Platyanthera K. Y. Pan Corolla campanulate; anthers hippocrepiform; seed coat densely spiny-processed; pollen exine fine-reticulate, tectum perforate, luminae small, nearly equal in size. In the section Stomactin, although the constriction of corolla at its throat is a specialized character, the characters of seed coat, pollen grains and anthers are apparently primitive. Therefore it may be said at least that more primitive characters are preserved in the section. In the section Oreocharis, on the contrary, the characters of corolla, seed coat and pollen exine are all advanced. And in the section Platyanthera, the seed coat, pollen (with perforate tectum) and anthers have developed rather specialized characters.