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1.
海南竹类的地理分布及区系特征   总被引:1,自引:0,他引:1  
单家林 《植物研究》1997,17(4):403-408
通过对海南岛竹类区系地理成分进行统计、分析和对其分布、与邻近地区竹类区系关系的探讨,其区系特征归纳如下:1.拥有丰富的特有成分。2.区系的热带性质明显。3.分布上差异显著。4.区系原始、古老。5.与毗邻的广东竹类区系联系较多。  相似文献   

2.
Both the continental or island origin of Hainan, and the Indo-Malaysian or East Asian affinity of its flora, are debatable. In this study, 196 families, 1283 genera and 3894 species of Hainan plants were recognized. Patterns of seed plant distribution were quantified at the generic and the family levels. The floras of Vietnam, and the adjacent Guangxi and Guangdong provinces of mainland China, were compared with Hainan. The results showed that the flora of Hainan Island is dominated by families and genera with tropical distributions. Among its floristic elements, tropical Asian distributions make up 23.85% of the total flora, while East Asian distributions contribute only 3.74%. There are only 7 genera and c. 10% of species endemic to Hainan Island. The Hainan flora has strong similarities to the flora of Vietnam at the family and the generic levels, and also to the flora of Guangxi, but less with the adjacent Guangdong province. The main conclusions are: Hainan’s flora is tropical in nature with a strongly tropical Asian affinity, and it has very low endemism at the generic and species levels, which implies a continental origin. We conjecture that Hainan Island could have been adjacent to northern Vietnam and the Guangxi at least in Eocene. This suggestion is supported by palaeobotanical, palaeomagnetic and volcanism studies.  相似文献   

3.
被子植物虫媒传粉植物的物种分化通常被认为是花性状响应传粉环境(传粉者)的空间变异而发生适应性分化的结果。通过对鼠尾草属(Salvia) 3个物种(共4个居群)传粉互作系统的比较, 探索了花性状对不同传粉环境的进化响应。结果表明: 各居群的传粉者组成、主要传粉者类型及其大小各不相同, 杠杆状雄蕊及相关花部性状大小在不同居群间具有显著差异; 各居群均表现出腹部传粉和背部传粉2种传粉模式, 但背部传粉仍然是最有效的传粉方式; 居群间杠杆状雄蕊长度与传粉者体长表现出极显著的正相关, 然而花冠长与传粉者体长表现出负相关; 花冠口高度和柱头高度与传粉者胸厚也表现出一定的协同变异。鼠尾草属植物的杠杆状雄蕊及相关花部性状在传粉系统的进化过程中表现出高度的可塑性, 表明雄蕊杠杆传粉机制对传粉环境的变异非常敏感, 在该属植物的物种分化过程中具有关键作用。  相似文献   

4.
赖碧丹  邓征宇  孙奇 《广西植物》2020,40(10):1520-1530
广西是报春苣苔属植物的世界分布中心,特有种较多。该研究针对线叶报春苣苔(Primulina linearifolia)、条叶报春苣苔(P. ophiopogoides)、刺齿报春苣苔(P. spinulosa)、大根报春苣苔(P. macrorhiza)、线萼报春苣苔(P. linearicalyx)、癞叶报春苣苔(P. leprosa)、桂中报春苣苔(P. guizhongensis)、百寿报春苣苔(P. baishouensis),八种广西特有种的开花物候期、开花动态、子房发育情况、花粉活性等开花生物学特性进行了研究。结果表明:(1)八种广西特有报春苣苔属植物在野外及人工环境下部分种在花期、单株开花量、单花开放持续时间具有显著性差异。人工栽培植株在单株开花量、单花开放持续时间要优于野生植株。(2)不同物种的单花花期长短不同,为3~14 d。雄蕊在花蕾阶段已经基本完成生长。雌雄蕊成熟期不一致,雄蕊先于雌蕊成熟。(3)花冠半开放至完全打开阶段的花粉活性最高,均在90%以上。(4)花冠完全开放阶段的柱头可授性最强。(5)自花授粉不能结实,异花授粉可正常结实,自交种子发芽率在80%以上。综上结果不仅为解决珍稀物种的繁殖障碍和保存种质资源提供了数据支持,而且对后续提高报春苣苔属的杂交育种成功率具有重要意义。  相似文献   

5.
朱华 《植物科学学报》2021,38(6):839-843
当前海南岛植物区系以热带分布的科和属占绝对优势,在属的地理成分上热带亚洲分布属的比例最高,显示出它是一个热带性质的植物区系,并具有热带亚洲亲缘。在海南植物区系中,仅有7个特有属和约10%的特有种,极低的特有性显示了它具有明显的大陆起源特征。通过比较研究发现,中国海南植物区系与越南植物区系关系最密切,其次是广西植物区系。在哺乳动物上,也显示出与植物区系类似的生物地理格局,中国海南与越南的联系最密切。古植物学研究揭示海南岛在始新世时曾具有亚热带性质的植物区系和亚热带气候,处在比现今更北的位置。古地磁学研究揭示在中生代时期海南岛连接着越南和中国广西,处于比现在高5~6个纬度的位置。综合各方面的研究,我们从生物地理的角度提出中国海南岛在始新世时曾连接着越南和中国广西,后来发生了向东南移动和旋转,最终到达现在的位置。  相似文献   

6.
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.  相似文献   

7.
Attraction of pollinators and successful pollen transfer represent the primary targets of selection during flower evolution, leading to repeated evolutionary shifts between pollinators and consequently to the diversification of floral forms. However, most studies in floral evolution focus on the characteristics of flowers with straight corolla tube. Here, we report on an unusual form of sigmoid corolla combined with protandry and herkogamy in a Chinese species of Gesneriaceae, Oreocharis pumila (formerly Opithandra pumila). Contrary to species with sigmoid corollas studied previously, the base of the corolla tube of this species is inclined at an oblique angle downwards before the tube bends forward, and the stigma and anthers are included in the upper part of the corolla tube. The plants were found to be self‐compatible but incapable of autonomous selfing. Successful pollination was found to depend fully on the presence of insect pollinators (Nomia sp.) and pollen grains are the greatest reward for the visitors. Different from the other sigmoid flowers, the sigmoid corolla of O. pumila was not found to favor insect pollinators with long flexible proboscises. A mechanical fit between floral morphology and pollinator was found, in which only small insect visitors with specialized visiting behavior are legitimate pollinators. The protandry combined with herkogamy in the sigmoid corolla tube strongly ensures pollination efficiencies. Oreocharis pumila is the only species with sigmoid corolla in the genus Oreocharis. We hypothesize that such a corolla has arisen through selection due to inadequate pollination in early spring in the mountainous habitat that O. pumila occupies.  相似文献   

8.
Charcoalified fossil flowers of a new genus and species (Paradinandra suecica) with affinities to Ericales s.l. (sensu lato) are described from the Late Cretaceous (Santonian-Campanian) from Southern Sweden. The flowers are pentamerous, hypogynous, and actinomorphic. Aestivation of sepals and petals is imbricate-quincuncial. The androecium consists of an outer whorl with single episepalous stamens and an inner whorl with paired epipetalous stamens. Pollen is small and probably tricolpate. Three carpels form a syncarpous ovary with numerous campylotropous ovules on parietal placentae. The styles are free for most of their length. The structure of mature fruits and seeds is unknown. Clear distinction of sepals and petals, possible dehiscence of anthers by restricted slits, presence of a nectary, and the general floral construction (salverform corolla) with a canalized access to the floral center clearly indicate insect pollination of the fossil flowers. Comparisons with extant taxa demonstrate that Paradinandra suecica shares many similarities with Ericales s.l. and in particular with members of Ternstroemiaceae, Theaceae, and Actinidiaceae. However, it is neither identical to any one genus of these families nor to any of the previously described ericalean taxa from the Cretaceous and thus provides further evidence of the diversity of Cretaceous ericalean plants.  相似文献   

9.
那坡县种子植物区系的特有现象   总被引:7,自引:1,他引:6  
地处桂西南的那坡县迄今计有种子植物174科,889属,2201种。其中东亚特有科5个,中国特有属15个,那坡特有种39个。这一地区不仅植物种类丰富,而且特有现象较为显著。在15个中国特有属中,1属为那坡本地的的特有属,4属为苦苣苔科植物。中国特有种的各亚型以及39个那坡特有种所隶属的分布区类型的分析均表明,该植物区系具有强烈的热带亚洲特色。石灰岩山地的特有文化发展则是那坡植物区系的另一个显著特征,这种特有化发展在苦苣苔科中表现得尤为显著。  相似文献   

10.
According to the concept of pollination syndromes, floral traits reflect specialisation to a particular pollinator or set of pollinators. However, the reproductive biology of endemic, and often specialised, plants may require increased attention as climate change accelerates worldwide. Species of Roscoea endemic to the Himalayan region have striking orchid-like flowers with long corolla tubes, suggesting pollination by long-tongued insects. Until now, the reproductive biology of species of Roscoea has been poorly documented. We investigated the floral biology, breeding system and pollination ecology of R. cautleoides and R. humeana, from Hengduan Mountains, a global biodiversity hotspot in southwest China. We also tested whether floral longevity increases pollination success. Pollination experiments showed that the two species were self-compatible and depended on insects for fruit production. Over several flowering seasons we did not observe any potential pollinators with long tongues that matched the corolla tube visiting flowers in centres of distribution. The principal pollinators observed were pollen-collecting generalist bees, with low visitation frequencies. In general, members of the ginger family are characterised by short-lived (usually 1 day) flowers, but flowers of R. cautleoides and R. humeana last 8 and 6 days, respectively. Removing stigmas decreased fruit set in both study populations. Our results suggest that the original pollinators may have been long-tongued insects that are now absent from the Chinese Himalayas because habitats have responded to climate change. However, long-lived and self-compatible flowers, coupled with the presence of generalist pollinators, are traits that have allowed these gingers to reproduce and continue to persist in the alpine habitats.  相似文献   

11.
广东种子植物区系与邻近地区的关系   总被引:9,自引:0,他引:9  
廖文波  张宏达   《广西植物》1994,14(3):217-226
广东省共有种子植物约219科1434属4986种。植物区系分析和比较表明,广东种子植物区系与桂中、桂东南、湘南、赣南、闽南、闽西南、闽中植物区系最为密切,都含有丰富的华南植物区系成分,其森林区系的特征成分尤为相似,它们共同组成了华南植物区系省;另广东与海南、中南半岛北部的关系方较为密切,充分显示了北回归线地区亦即热带亚热带过渡地区植物区系的整体性特点。  相似文献   

12.
本文研究了华南地区羽枝藓属(Pinnatella)和凋叶藓属(Caduciella)植物.简要讨论了羽枝藓属和凋叶藓属的系统位置.确认华南地区产羽枝藓属4种,即爪哇羽枝藓(P.anbigua)、纤细羽枝藓(P.anacamptolepis)、嵌边羽枝藓(P.intralimbata)和东亚羽枝藓(P.makinoi),凋叶藓2种,即广东凋叶藓(C.guangdongensis)和凋叶藓(C.mariei).其中爪哇羽枝藓为广东、贵州、海南岛之新记录,纤细羽枝藓为中国大陆(广东、广西)和海南岛之新记录,东亚羽枝藓为福建、广西和海南岛之新记录,广东调叶藓为海南岛之新记录,暂将P.alopecurioides处理为存疑种。本文还包括分种检索表、各种的简要识别特征、产地及生境资料.  相似文献   

13.
Observations on the floral biology of seven species of New World Lecythidaceae, including the first report of bat pollination for neotropical members of the family, are presented. The shift from actinomorphic flowers with many stamens to zygomorphic flowers with fewer stamens and the concomitant change from pollen to nectar as the pollinator reward are discussed and related to the respective pollinators. Several mechanisms which operate to reduce competition for pollinators between sympatric species of the family are suggested.  相似文献   

14.
杠杆状雄蕊是鼠尾草属(Salvia)物种形成的关键性状, 背部杠杆传粉模式作为该属植物与传粉者精确互作的经典案例被广泛深入研究, 但是在该属物种中还存在许多非典型的杠杆结构和传粉模式。雄蕊结构及其与传粉者互作的多样性, 使得鼠尾草属成为研究植物传粉模式转变的模式材料, 舌瓣鼠尾草(S. liguliloba)即是一种具非典型的退化杠杆状雄蕊结构和传粉特征的代表性物种。该文着重对舌瓣鼠尾草的花器官结构和传粉特征进行研究, 并与具有短药隔杠杆的毛地黄鼠尾草 (S. digitaloides)做比较分析, 以期揭示退化杠杆可能的进化选择压力及其生态学意义。结果表明, 舌瓣鼠尾草具有较短的花冠、更窄的冠筒和较短的雄、雌蕊(p < 0.05)。退化萎缩的雄蕊下臂, 冠筒内的狭小空间限制了唯一的有效传粉昆虫——三条熊蜂(Bombus trifasciatus)推动雄蕊做杠杆状运动, 而是靠近花药直接利用头部完成授粉。相比经典的杠杆状雄蕊结构及其传粉过程, 小型花冠和退化杠杆雄蕊是对专一性和活跃度较高传粉昆虫的适应, 可能具有完全不同的进化途径和繁殖策略。  相似文献   

15.
Wentsaiboea renifolia D. Fang & D. H. Qin, a new genus and species of Gesneriaceae from Guangxi, China, is described and illustrated. This genus is similar to Dolicholoma D. Fang & W. T. Wang in the shape of stigma, but differs by having leaves reniform, palmately nerved and base cordate, corolla obliquely campanulate, corolla lobes rounded, and both stamens and staminodes adnate to corolla tube near base. It is also similar to Chiritopsis W. T. Wang in the habit, but differs by having leaves palmately nerved, corolla tube campanulate and abaxially swollen, and stigma hippocrepiform.  相似文献   

16.
该研究在建立贵州省野生苦苣苔科植物名录和地理分布数据库的基础上,对其物种多样性及地理分布格局进行研究。通过文献资料结合实地调查,从物种组成、特有性、水平分布、垂直分布和相似性等方面进行分析,并采用筛除算法确定贵州苦苣苔科植物分布的热点地区。结果表明:(1)贵州省苦苣苔科植物共计2族8亚族28属153种(含种下等级),分布在75个县级行政区,有128/45个中国/贵州特有种,垂直分布以900~1300 m海拔段最为丰富。(2)通过计算省级相似性系数,发现贵州与广西的相似程度最高,最后筛选得到10个热点县,共代表了75%的苦苣苔科植物。(3)贵州省为典型的喀斯特高原山地,苦苣苔科植物种类丰富,尤其是广义马铃苣苔属、广义报春苣苔属、广义石山苣苔属和蛛毛苣苔属等,有着较高的物种多样性和区域特有性。该研究可以为贵州省苦苣苔科植物资源保护和持续利用提供理论参考。  相似文献   

17.
亚洲特有植物风筝果(Hiptage benghalensis)镜像花(mirror-image flowers)的雌雄异位变化极大, 柱头与可育花药的空间距离在海南岛与云南西双版纳种群仅有2-4 mm, 而在贵州及云南东南部种群可达10-12 mm。为验证 “镜像花雌雄异位的变化是各个地理种群受到传粉昆虫体型大小选择的结果”假说, 本文开展了传粉生态学与分子生物学研究, 探讨风筝果不同地理种群的雌雄异位变化是否与当地传粉者体型相关, 是否有着遗传基础, 以及是否形成了“传粉生态型”(pollination ecotype)。结果表明, 雌雄异位程度大的贵州种群和云南东南部种群, 其传粉者也是体型较大的木蜂(Xylocopa nasalis)和熊蜂一种(Bombus sp.); 雌雄异位程度小的海南岛种群和云南西双版纳种群的传粉者则是体型较小的大蜜蜂(Apis dorsata)、西方蜜蜂(A. mellifera)。除了雌雄异位的明显分化(F = 53.69, P < 0.01)之外, 花柱长度也在这两类种群之间差异显著(F = 12.5, P < 0.05), 与传粉昆虫身体长度密切相关。通过叶绿体ycf1b、rbcL和细胞核ITS 3个DNA片段的序列分析, 由大型蜂传粉的雌雄异位程度较大的3个种群(贵州和云南东南部种群)遗传关系极近, 与小型蜂传粉种群(雌雄异位较小的海南岛种群和云南西双版纳种群)存在明显的遗传分化。这些结果显示, 风筝果不同地理种群的镜像花雌雄异位程度的变化可能是适应局域不同体型大小的传粉昆虫的选择结果, 而且种群间出现了基因流的隔断, 可能与大型蜂、小型蜂传粉的两种生态型有关。镜像花通过雌雄异位的变化适应不同地域的传粉者而形成传粉生态型, 这种传粉生态型及其传粉隔离机制可能是风筝果属物种形成与维持的一个重要原因。  相似文献   

18.
Boeica konchurangensis B.H.Quang, D.V.Hai & Mich.Möller, a new species of Gesneriaceae from the Gia Lai Province of Vietnam is described, illustrated, and colour photographs of the species are provided. This new species has an almost actinomorphic corolla and shows morphological similarities with B. porosa, but differs from it by a shorter peduncle, a near‐actinomorphic purple corolla with a distinctly broad campanulate tube and a shorter capsule.  相似文献   

19.
广西苦苣苔科一新属——文采苣苔属   总被引:1,自引:0,他引:1  
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。  相似文献   

20.
中国广西苦苣苔科一新种--灵川小花苣苔   总被引:1,自引:0,他引:1  
报道了在广西岩溶洞穴发现的苦苣苔科Gesnenaceae小花苣苔属Chiritopsis一新种——灵川小花苣苔C.lingchuanensis Yah Liu&Y.G.Wei。本种因聚伞花序花稀疏,花冠白色,明显二唇形,上唇比下唇短3倍以上,退化雄蕊3而与羽裂小花苣苔C.bipinnatifida W .T.Wang相近,区别在于前者叶不裂,雄蕊被短柔毛。本种在叶形上还与小花苣苔C.repandaw T.Wang相近,不同在于后者花冠不明显二唇形,上下唇近等长,雄蕊无毛,退化雄蕊2。灵川小花苣苔的分布范围狭窄,目前仅见于一个岩溶洞穴的近洞口段,具明显的洞生习性。  相似文献   

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