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。     

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)。     

广西小花苣苔属(苦苣苔科)一新变种——阳朔小花苣苔

报道了在广西桂林阳朔县发现的苦苣苔科小花苣苔属一新变种——阳朔小花苣苔。新变种与原变种的主要区别在于叶较小;叶柄、花序梗、花梗、苞片和花萼不具紫色腺体;叶中脉及侧脉常具银白色脉纹;花期6、7月,晚于原变种花期。     

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。     

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     

Three new species of Gasteranthus (Gesneriaceae) from Ecuador

The gesneriad flora of the Reserva Río Guajalito, Province of Pichincha, and Bosque Protector Otonga, Province of Cotopaxi, Ecuador have been investigated. Three new species,Gasteranthus aurantiacus M. Freiberg,G. atrolimbus M. Freiberg, andG. acuticarinatus M. Freiberg, are described and illustrated in preparation for a contribution for the Gesneriaceae in the Flora of Ecuador. While bothG. acuticarinatus andG. atrolimbus are characterized by a dorsal keel on a tubular, pink to wine-red corolla, the infundibulate, bright orange-colored corolla ofG. aurantiacus has a rather wide opening and a large limb.     

中国特有河口异叶苣苔（苦苣苔科）胚胎学研究

对河口异叶苣苔的胚胎学观察旨在为该属的系统学研究提供参考。该种的花药药壁由表皮、药室内壁、中岐和绒层４层细胞组成。２－３－核细胞在绒毡层频繁出现。胚珠属倒生,单珠被和薄珠心。胚囊发育属蓼型。该种胚囊发中的双大孢子母细胞现象,分别为并列和前后排列型。前者发育至双并列四分体,后者发育到呈棱形的４个大孢子。胚乳的发育属细胞型。并在合点端和珠也端分别具有吸器。珠孔吸器发育早期为单核、２－细胞、后期为两核、２－细胞或单核、４－细胞,有时为多细胞,并在发育过程中向外伸长形成外珠孔。合点吸器为两核。由于合点吸器和珠孔吸器的活动,位于珠被最外层细胞的珠和被绒毡层之间的２－３层细胞逐渐解体和被吸收,胚的发生和发育属柳叶菜型,在胚的发育过程中,胚乳几乎被吸收耗尽,仅利下一层胚乳细胞紧贴内种皮,成熟种子的种皮由珠被最外层细胞和珠被绒毡层发育而来,本文对河口异叶苣苔的胚胎发育过程员苦苣苔科其它类群进行了广泛的比较和讨论。     

单种属弥勒苣苔属系统位置研究 基于分子和细胞学数据

弥勒苣苔属是苦苣苔科的单种属,仅分布于中国西南部。为探讨弥勒苣苔在苦苣苔亚科中的系统位置,我们选择了苦苣苔亚科116个类群,外类群为苦苣苔亚科以外的7个物种。用最大简约法（MP）和贝叶斯分析（BI）,对以上类群的核基因ITS以及两个叶绿体基因trnL-F、atpB-rbcL数据进行了独立和联合分析。在三个片段联合分析的结果中,弥勒苣苔与马铃苣苔属、后蕊苣苔属、金盏苣苔属、直瓣苣苔属以及川鄂粗筒苣苔构成一个强烈支持的分枝。MP树中,此分枝为并系,而在BI分析中,弥勒苣苔与川鄂粗筒苣苔、直瓣苣苔属互为姐妹类群。同时,第一次报道了弥勒苣苔的染色体数目（2n=34）。根据前人报道,马铃苣苔属、后蕊苣苔属、粗筒苣苔属和直瓣苣苔属的染色体数目同为2n=34,这进一步支持我们的分子系统发育分析。     

Confirmation of a natural hybrid species in Petrocosmea (Gesneriaceae) based on molecular and morphological evidence

A natural hybrid species in Petrocosmea named Longianthera in Yanshan County,Yunnan Province is confirmed for the first time based on molecular and morphological evidence.The character count procedure of the variable characters show that Longianthera populations are characteristic of the intermediate morphological traits between its putative parents Yanshan and Petrocosmea martinii.The nuclear ribosomal internal transcribed spacer region and three chloroplast regions of matK,trnL-F,and trnT-L are sequenced in the putativehybrid and the related species.Both alignment of DNA sequences and the phylogenetic trees could exclude all the other species in Petrocosmea as the parental species except for Yanshan and P martinii.Eight haplotypes in the 31 internal transcribed spacer sequences and six haplotypes in 42 cpDNA sequences were found from 14 individuals of Longianthera populations.The analyses of DNA sequences,haplotypes,and phylogenetic trees indicate that Longianthera is likely a hybrid species between its putative parents Yanshan and P martinii,in which Yanshan might be the most possible maternal parent.Several factors may contribute to the natural hybridization between these two parental species in Petrocosmea,such as the overlapped geographic distribution,habitats,flowering periods,and shared pollinators.Finally,the new species of Yanshan and the natural hybrid species of Longianthera are described.     

Expression pattern of CYC-like genes relating to a dorsalized actinomorphic flower in Tengia (Gesneriaceae)

Tengia has been called a "natural peloria" in the family Gesneriaceae because it exhibits an almost perfect actinomorphic flower from whorl one to whorl three. It would be especially interesting to know whether or how CYC-like gene activities are related to this type of perfect actinomorphic flower. To address this, we have isolated four CYC-like TCP genes and carried out an investigation on their expression patterns in Tengia. TsCYC1C and TsCYC1D have similar expression patterns with strong signals being detected in all five petals and stamens, whereas TsCYC2A and TsCYC2B are only transiently expressed in the very early floral meristem. Our results suggest that the expansion of the expressions of TsCYC1C and TsCYC1D from the dorsal to the ventral petals is likely responsible for the evolutionary formation of the fully dorsalized actinomorphic corolla, that is, an expanded functional domain of CYC-like gene dorsal identity in Tengia corolla. However, the expressions of TsCYC1C and TsCYC1D are not correlated with stamen abortion; therefore, TsCYC genes do not functionally repress the stamen development in Tengia flowers. This is probably due to changed cis-activities that result in the cell cycle-related genes uncoupling from the TsCYC regulatory pathway in Tengia.     

Altered expression patterns of TCP and MYB genes relating to the floral developmental transition from initial zygomorphy to actinomorphy in Bournea (Gesneriaceae)

The shift from zygomorphy to actinomorphy has been intensively studied in molecular genetic model organisms. However, it is still a key challenge to explain the great morphological diversity of derived actinomorphy in angiosperms, since different underlying mechanisms may be responsible for similar external morphologies. Bournea (Gesneriaceae) is of particular interest in addressing this question, as it is a representative of primarily derived actinomorphy characteristic of a unique developmental transition from zygomorphy to actinomorphic flowers at anthesis. Using RNA in situ hybridization, the expression patterns were investigated of three different Bournea orthologues of TCP and MYB genes that have been shown to control floral symmetry in model species. Here, it is shown that the initial zygomorphic pattern in Bournea is likely a residual zygomorphy resulting from conserved expression of the adaxial (dorsal) identity gene BlCYC1. As a key novel event, the late downregulation of BlCYC1 and BlRAD and the correlative changes in the late specific expression of the abaxial (ventral) identity gene BlDIV should be responsible for the origin of the derived actinomorphy in Bournea. These results further indicate that there might be diverse pathways in the origin and evolution of derived actinomorphy through modifications of pre-existing zygomorphic developmental programs under dynamics of regulatory networks.     

Developmental morphology of one-leaf plant Monophyllaea singularis (Gesneriaceae)

 Developmental morphology is described of the one-leaf plant Monophyllaea singularis which possesses a huge macrocotyledon, a long petiolode below it, and many small inflorescences scattered along the petiolode and midrib. Cell proliferation and basipetal differentiation occur in both cotyledons after water imbibition and germination. The basal meristem forms from a group of small, least differentiated cells at the base of a future macrocotyledon and continues blade production even at the reproductive stage. The petiolode meristem, which forms as an intercalary meristem near the base of the macrocotyledon, contributes to the elongation of the petiolode and the midrib. Although the 'groove meristem', like the groove meristem of Streptocarpus, forms between the cotyledons at the site of a shoot apical meristem, it is not involved in inflorescence production. In M. singularis, instead of the 'groove meristem', the inflorescences are initiated adventitiously from groups of cells in the dermal and subdermal layers of the petiolode and probably also of the midrib. Received October 10, 2000 Accepted August 2, 2001