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。     

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(p ara l lel ism )。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。     

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。     

云南马先蒿属植物的生物地理及物种多样性

马先蒿属（Pedicularis)是被子植物中最大的属之一,在云南植物区系中占有重要地位。按照钟补求系统,该属植物在云南有151种分属于13个群72个系。马先蒿属在云南的地理分布体现了下列特点：（1）种类十分丰富,占整个属总种数的25％,占中国的42．6％。（2）包括了该属全部花冠类型,即无齿、有齿的原始类型各为24种、短管具喙的中间过渡类型87种,较进化的长管类型16种。（3）马先蒿属植物分布在云南的11个地理分布区域中,但该属植物在康藏高原区最为丰富,有108个种在本区有分布,占云南种数的71．5％;横断山植物区和东喜马拉雅植物区是本属的现代分布中心和多样性中心。（4）特有现象十分明显,其中8个系、52个种为云南特有,横断山和东喜马拉雅的特有种量为丰富,也是本属的特有中心。（5）民先蒿植物与邻近的四川（西南部）和西藏（东南部）在区系上联系密切,与缅甸和不丹有一定的联系。     

云南马先蒿属植物的生物地理及物种多样性

马先蒿属(Pedicularis)是被子植物中最大的属之一,在云南植物区系中占有重要地位.按照钟补求系统,该属植物在云南有151种分属于13个群72个系.马先蒿属在云南的地理分布体现了下列特点:(1)种类十分丰富,占整个属总种数的25%,占中国的42.6%.(2)包括了该属全部花冠类型,即无齿、有齿的原始类型各为24种、短管具喙的中间过渡类型87种,较进化的长管类型16种.(3)马先蒿属植物分布在云南的11个地理分布区域中,但该属植物在康藏高原区最为丰富,有108个种在本区有分布,占云南种数的71.5%;横断山植物区和东喜马拉雅植物区是本属的现代分布中心和多样化中心.(4)特有现象十分明显,其中8个系、52个种为云南特有,横断山和东喜马拉雅的特有种最为丰富,也是本属的特有中心.(5)云南马先蒿植物与邻近的四川(西南部)和西藏(东南部)在区系上联系密切,与缅甸和不丹有一定的联系.     

开花式样对传粉者行为及花粉散布的影响

理解植物花的特征可以从单花特征和群体特征两个层次入手。开花式样是植物的花在群体上的特征体现, 通过在开花数目、开花类型以及花的排列上的变化, 不同的开花式样对传粉者具有不同的吸引力, 影响昆虫在植株上的活动, 使花粉运动的方向发生相应变化, 从而影响着植物最终的交配结果。此外开花式样随环境改变也会发生一些变化。本文介绍了开花式样研究的进展, 对开花数目、开花类型以及花的排列等3个方面的已有研究进行了分别阐述, 并提出开花式样研究应更多地考虑影响传粉的各种因素。     

马先蒿属6个种的核型与进化研究

分析和报道了马先蒿属分布于青藏高原东北部６个特有种的核型,并根据核型及其有关参数,分析和比较了该６种马先蒿核型的不对称性和相对进化程度。６个种的体细胞染色体数目都是２ｎ＝１６。核型分别为：绵穗马先蒿Ｐ．ｐｉｌｏｓｔａｃｈｙａ Ｍａｘｉｍ．,核型公式Ｋ（２ｎ）＝１６＝４ｍ＋１２ｓｍ,染色体相对长度组成２Ｌ＋６Ｍ２＋６Ｍ１＋２Ｓ,核型不对称系数Ａｓ·Ｋ＝６５．２９％,属于２Ａ型;青海马先蒿Ｐ．ｐｒｚｅ     

角蒿属(紫葳科)的花粉形态

对角蒿属(Incarvillea Juss.)14个种(4变种,2居群)的花粉进行了扫描电镜观察。角蒿属花粉形态较为相似,为单粒花粉,花粉粒扁球形至近球形,外壁表面同时具有近刺状和穴状两种纹饰。大小在28～51μm之间,萌发孔为多沟型,6～10沟,沟长度不等,沿赤道分布,一些种类中沟多少弯曲使萌发孔成螺旋状,沟末端在极面上多少连接形成合沟。角蒿属内种间花粉形态上的相似性说明了角蒿属应为一单系类群,而对于角蒿属下单元划分及种间的系统有着有限的意义,波罗花亚属花粉明显大于其它两个属,花粉形态特征也显示了它与角蒿亚属关系较近。同时,研究结果不支持将角蒿属放在硬骨凌霄族(Tecomeae)。     

虫媒植物与传粉昆虫的协同进化

虫媒植物与传粉昆虫的协同进化史刚荣（甘肃省陇西师范学校,７４８１００）地球上大约在３５亿年前就开始出现生物。目前,已经过鉴定的全球生存的生物约在１７０多万种以上（世界资源报告,１９８６）,其中被子植物就有２０万种以上,在这些开花的被子植物中,有８０％...     

植物物种的快速鉴定与iFlora：DNA条形码在马先蒿属中的应用

DNA条形码技术就是利用一段较短的标准DNA序列对物种进行快速鉴定。与基于植物外部形态特征的传统分类鉴定方法相比,DNA条形码具有高效、准确,且易于实现自动化和标准化的特点。马先蒿属（PedicularisL．）植物具对生（轮生）叶的种类70％以上分布在中国．近缘种间形态上非常相似,鉴定较为困难。研究选取马先蒿属具对生（轮生）叶类群43种164份样品,利用叶绿体基因（rbcL、matK、trnH-psbA）和核基因（ITS）条形码片段,采用建树法和距离法检验4个条形码对这些物种的鉴定效果。结果表明,ITS片段用于建树法和距离法的鉴别率分别为81．40％和89．57％,其鉴别率高于3个叶绿体基因片段和任一基因片段的组合条码。另外,利用ITS成功解决了一些疑难种的分类问题。DNA条形码在马先蒿属研究中的实用性为新一代植物志（iFlora）实现物种的快速和准确鉴定提供了有力支持,并能为分类学、生态学、进化生物学、居群遗传学和保护遗传学等分支学科的研究提供重要信息。     

The Pollination Syndrome of Pedicularis rex (Scrophulariaceae) and Its Biogeographic Significance

The pollination biology of different populations of Pedicularis rex Clarke C B. was studied in Zhongdian of Northwest Yunnan and in Kunming of central Yunnan, respectively. Seed production depends exclusively upon pollination by bmnblebees ( Bombus Latr. ). The flowers are yellow, with short-tubed, erostrate and nectarless corolla. Two species of the bumblebee workers, Bombus friseanus Skorikov and B. lucorum L. foraged in an upright (nototribic) position for pollen. Meanwhile, Bombus friseanus workers also foraged in an inverted (stemotribic) position on P. rex, vibrating pollen from the anthers within the galea. This pollination syndrome was previously reported in the North American species, e.g.P, labradorica which has the same corolla-type with P. rex. A comparison of the corolla types and pollination syndrome on the species of Pediadaris in East Asia and North America indicates that such a pollination syndrome may be only found in the primitive corolla type of Pedicularis. In spite of the separation in the geological history, P. rex and P.labradorica share the same corolla type and pollination syndrome. Further study is needed to elucidate the biogeography of the Pedicularis.     

Pollination Ecology and Endemism of Pedicularis pulchella Pennell (Scrophulariaceae)

Abstract Pedicularis pulchella Pennell, endemic to sparsely vegetated areas of alpine tundra scree in southwestern Montana and northwestern Wyoming, was found to be roat-hemiparasitic and obligately dependent for its pollination upon bumblebees of three non-tundra species that forage primarily in an inverted position for pollen scraped from anthers concealed in the galea, This sternotribic pollination syndrome is considered related to the short (5–6mm) proboscides of pollinators on flowers with deep (12.4mm), nectariferous corolla tubes and favoring pollen as an insect attractant. Photographic and spectropholomelric analysis of the red-purple floral color included prominent blue corolla and ultraviolet calyx reflections corresponding to dominant colors of bumblebee visual spectra. Nectar analysis by thin-layer chromatography and refractomctry indicated, respectively, the presence of fructose and sucrose, and a sucrose-equivalent concentration of dissolved solids exceeding 50%; both coincide with the general pattern of the genus. Analysis of pollen from corbicular loads of P. pulchella pollinators indicated relatively low pollen-constancy of insects and substantial foraging association with Vaccinium in the montane-subalpine zone. By contrast, pollinators on P. cystopteridifolia and Phyllodoce glanduliflora in a diverse tundra plant community on rich alpine turf revealed broad pollinator spectra (7–8 species), high pollen-foraging constancy on Pedicularis, and high nectar-foraging frequency on Phyllodoce : The pollination ecology and endemism of Pedicularis pulchtella are interpreted in terms of resource sharing, spatial competition of plant species, and selective stress of the physical environment.     

Pollination Ecology and Endemic Adaptation of Pedicularis howellii Gray (Scrophulariaceae)

Abstract Pedicularis howellii , endemic to the Siskiyou Mountains of California-Oregon, is a root hemiparasite obligately dependent upon bumblebee pollinators that remove pollen by vibration from its short-tubed, nectarless, rostrate flowers, which reflect visible and ultraviolet (360nm) light attractive to Bombus foragers. All six Bombus species in the study area pollinated the plant, but only on P. howellii and P. racemosa were B. mixtus workers the most abundant pollinators among the seven bumblebee-pollinated plants studied, including Delphinium decorum, Dodecatheon jeffreyi, Penstemon newberryi, P. shastensis, and Phacelia heterophylla. Analysis of corbicular pollen loads of Bombus pollinators indicated that pollen foragers on Pedicularis species were less pollen-constant than all other bumblebee pollinators. Although P. howellii and P. racemosa blooming periods overlapped slightly, phenological isolation of blooming periods of plants sharing the same pollinators was not evident. Chemical soil analysis of its habitat and quadrat analysis of the population structure of Pedicularis howellii indicated that the plant grows in a moderately fertile forest soil and is restricted to the edge of forest canopy openings where sunlight favors development of plants to the flowering stage. The endemism of P. howellii is related to a similar "edge effect" survival of P. furbishiae in a boreal forest riparian habitat previously studied.     

Pollination Ecology of Pedicularis punctata Decne. (Scrophulariaceae) in the Kashmir Himalaya

Abstract The pollination ecology of Pedicularis punctata was studied in the Pir Panjal Range of the Kashmir Himalaya in the summer of 1989. Its nectarless, rostrate, long-tubed flower was found to be pollinated exclusively by Bombus foragers vibrating pollen while the stigma contacted pollen in the pollinator's cervical crevice. Workers of Bombus tunicatus and B. flavothoracicus comprised 95% of its pollinators. Pollen-foraging fidelity of its pollinators was greatest where diversity of Bombus -pollinated plant species in three plant communities was least. Foragers on other plants carried virtually no Pedicularis pollen. P. punctata is a mid-season blooming species similar in its pollination syndrome to comparable species in other geographic regions. The enigmatic function of its long, nectarless corolla tube, even more exaggerated in other Asiatic species, requires further investigation.     

A Preliminary Study of the Pollination Ecology of Pedicularis (Scrophulariaceae) in Japan

Abstract An introductory study of the pollination ecology of six Japanese species of Pedicularis conducted in 1982 and 1983 indicated a close parallel between characteristics of floral mechanisms in Japan and those previously investigated in North America. Floral color, floral form, total dissolved solids in floral nectar, and polinator behavior on flowers of Japanese species are similar to those of North American species. Blooming phenology of Japanese species also corresponds to the North American sequence of long-tongued, nectar-foraging queen bumblebees (Bombus Latr.) pollinating nectariferous , earlier-blooming species nototribically and short-tongued, pollen-foraging workers pollinating nectarless, rostrate flowers of later-blooming ones sternotribically. Electrofocus analysis of peroxidase systems in two Japanese species indicated considerable intrapopulational heterozygosity. Nectar component analysis of two transboreal species indicated intraspecific differences in kinds of sugars between widely disjunct Japanese and North American populations. A tentative conclusion is that the Japanese and North American Pedicularis floras have evolved in a parallel manner from Himalayan migrants, while their transboreal elements are in process of vicariant diversification.     

Pollination Ecology of Pedicularis megalantha D. Don (Scrophulariaceae) in the Himachal Himalaya

Abstract In the summer of 1990, the pollination ecology of Pedicularis megalantha was studied in the montane-subalpine spruce-fir forest zone (2750-3050 m) on the north slope of Mt. Huttoo at Narkanda, Himachal Pradesh, in the Indian Himalaya. Its yellow, long-tubed, nectarless flower with a curled rostrum overarched by a broad, inverted lower corolla lip was pollinated exclusively by Bombus albopleuralis and B. tunicatus workers hanging inverted from the corolla and vibrating pollen from introrse anthers concealed within the galea and releasing pollen through a small ventral opening in the galea base. The stigma, protruding from the tip of the rostrum, contacted pollen deposited on the ventral side of the insect's thorax. Corbicular pollen loads from P. megalantha pollinators indicated equal numbers of monolectic and oligolectic foragers. P. megalantha appeared to suffer from competition for pollinators by Cynoglossum wallichii at one site but to be favored in a mixed plant community with nectariferous species offering a forage resource complementary to Pedicularis pollen. As in P. punctata , the long, nectarless corolla tube of P. megalantha appears to function in extending the rostrate vibration pollination mechanism beyond the plant's foliage, which would interfere with its function. It is not an adaptation for nectar-foraging lepidopteran pollinators. P. megalantha was also found to be a root hemiparasite.