绣球属(Hydrangea L.)及近缘属花粉形态的研究

为深入研究绣球属植物花粉形态的分类学价值和系统学意义,厘清绣球属与近缘属之间的系统发育关系,该文利用扫描电子显微镜(SEM,scanning electron microscope)对国产绣球属及其近缘属41种绣球花科(Hydrangeaceae)植物的花粉形态以及表面纹饰进行了观察。结果表明:绣球属及其近缘属的花粉为三孔沟;形状多数为长圆体形或近球体形;赤道面观为椭圆形或圆形;极面观多为圆形,少数为三角形或圆三角形。花粉外壁纹饰可分为网状和孔穴状。网眼内的三级纹饰可分为光滑和具颗粒状突起。根据花粉形状和外壁纹饰类型将上述物种划分为4个组,即花粉的形状为长圆体形,表面纹饰为孔穴纹饰;花粉的形状为长圆体形,表面纹饰为网状纹饰;花粉的形状为近球体形,表面纹饰为孔穴纹饰;花粉的形状为近球体形,表面纹饰为网状纹饰。以上可进一步细分为8个类型。上述表明花粉形态证据可为绣球属及其近缘属的属下分类和种间界定提供重要佐证;但结合前人的系统发育重建分析该属植物花粉形态的系统学意义相对有限,如花粉形态证据对于该属及其近缘种属系统发育树上大支的界定难以提供有力的证据。     

Pollen morphology of the genus Cornukaempferia (Zingiberaceae) in Thailand

Cornukaempferia is a recently described genus of Zingiberaceae which only occurs in Thailand as a rare genus with limited geographical distribution. Only three species have been described so far, including a recently described new species, C. larsenii. These three species are morphologically very similar and additional data on other biological aspects are useful for the elucidation of their relationship. Pollen morphology of all three species of genus Cornukaempferia has been studied by light microscopy and scanning electron microscopy. The pollen grains are monad, spherical, inaperturate. The exine sculpture is echinate with psilate between the spines for C. aurantiflora and C. longipetiolata, or echinate with regulate between the spines for C. larsenii. This obser-vation helps support the taxonomic status of C. larsenii.     

Pollen morphology and structure of Tropical and Subtropical American genera of the Piptadenia -group (Leguminosae: Mimosoideae)

A survey of the pollen morphology of the American taxa of the Piptadenia -group (Mimoseae) was done including all together 384 species of the following genera: Piptadenia , Parapiptadenia , Pseudopiptadenia , Piptadeniopsis , Microlobius (= Goldmania ), Stryphnodendron , Adenopodia , Anadenanthera and Mimosa . Because of a high morphological and structural variation the definition and characterization of pollen types turned out to be very difficult. Nevertheless the presence and durability of some pollen characters allow a provisional grouping: (1) always tetrads or polyads, (2) small size 6 (20) 40 mum, (3) unstable shape but currently ovoidal and, if biconvex, ellipsoidal in the outline, (4) number of pollen grains of the polyads very variable and unstable; the most frequent numbers are 8-12-16, (5) pollen grains irregularly united in polyads, with homomorphous exine and, (6) pores always located in the angles of the pollen grains in distal-subdistal position, rarely subdistal, (7) without or with pseudocolpi or subpseudocolpi (never colpi) in the distal face, (8) endexine forming an annulus around the endoaperture with ends of free lamellae with a central white line, (9) the tectal stratum above the pores forming a small vestibular space (except in Anadenanthera ). These palynological characters or most of them confirm the affinity among genera in the Piptadenia -group and its distinction from other taxa of the subfamily Misosoideae with tetrads or polyads.     

Pollen morphology and functional dioecy inSolanum (Solanaceae)

Dioecy has evolved independently several times in the large, mostly tropical genusSolanum. In all cases of dioecy inSolanum functionally male flowers have normal anthers, normal pollen and reduced stigmas while functionally female flowers have stigmas and anthers that appear normal but contain non-functional, usually inaperturate pollen. The inaperturate pollen has living cytoplasm, but apparently never germinates and it has been hypothesised that the pollen in these functionally female flowers is retained as a pollinator reward. Pollen morphology is compared in twelve of the thirteen known dioecious species ofSolanum, and some stages in the the development of inaperturate pollen in the anthers of functionally female flowers ofSolanum confertiseriatum of Western Ecuador are examined. Observations on the development and morphology of inaperturate pollen in functionally female flowers ofSolanum are related to hypotheses about the evolution of dioecy in the genus.     

Infrageneric variability of pollen morphology in Palaua (Malveae,Malvaceae) and the taxonomic utility of quantitative pollen characters

Palaua (Malvaceae) comprises 15 species endemic to the coastal deserts of Chile and Peru. Previous molecular phylogenetic analyses have shown that this genus is monophyletic and can be subdivided into three clades. In the present study, pollen morphology of all species of Palaua was examined using light and scanning electron microscopy to determine whether it provides additional data in support of the proposed infrageneric groups. The pollen grains are spheroidal, medium to large in diameter, spinose and pantocolporate – the ectocolpi are very short. The tectum is perforate and characterised by granula. In all species the nexine is of a similar thickness in all areas of the pollen grain, while the sexine thickness varies, being notably thicker in the areas where the broad spine bases are sited (‘spine cushions’). Many of the quantitative characters have conspicuous variability, but the variability shows considerable overlap between species. Nonetheless, P. guentheri, P. inconspicua, P. malvifolia and P. modesta are united as a group by having the smallest pollen grains with the smallest apertures, the shortest spines and the shortest interspinal distance. This grouping reflects only partially the suggested infrageneric clades, although it does tend to unite the species with the smallest flowers. A possible link between reproductive resources and pollen size is also considered, as well as the influence of polyploidy. However, the taxonomic utility of these quantitative characters is weakened by species with more than one cytotype.     

Pollen morphology of selected Central European species from subgenera Vignea and Carex (Carex,Cyperaceae) and its relation to taxonomy

This study analysed the taxonomic utility of selected features of pollen grains of 45 Central European species of subgenera Vignea and Carex of the genus Carex. Seven quantitative features were analysed: [length of polar axis (P), length of equatorial axis (E), exine thickness on the pole (Exp), exine thickness on the equator plane (Exe), P/E ratio and the relative thickness of exine (Exp/P and Exe/E ratio)] and outline, shape and exine sculpture. Among the biometrical features, the most important for Carex taxonomy (particularly at the level of subgenus) is the thickness of exine (Exp). Marked differences in the morphological structure of inflorescences at the subgenus level are reflected in the differences of pollen features. Results of our studies clearly show an explicit (and not previously described in the palynological literature) taxonomic division of the genus Carex on the basis of pollen biometrical features into two units corresponding exactly to the subgenera (Vignea and Carex). However, the features of pollen grains analysed did not contribute any essential taxonomic criteria at levels lower than subgenus (e.g. sections). An exception was for C. disticha, where it was observed that the poroid areas occurred in pairs, a new feature for sedges. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 422–439.     

Biogeographic diversification in Nolana （Solanaceae）, a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.     

Pollen morphology of Justicia L. (Acanthaceae) from Thailand and its taxonomic value

The acetolysed pollen of 33 species of the genus Justicia in Thailand is investigated using both light and scanning electron microscopy. The pollen of the genus is characterised as being isopolar, bilaterally or radially symmetrical, with mostly prolate or prolate spheroidal shape. Based on characters with high factor loading in the cluster analysis and principal components analysis, the studied species are divided into two major groups; one with 3-colporate with six pseudocolpi and the other with 2-porate or 2–3-colporate with aperture areas. The pollen morphology of each group is described and illustrated. Pollen characters are useful for taxonomic delimitation and relationships among Thai species.     

亚洲茜草科粗叶木属及其相关属植物花粉形态研究

利用光学显微镜和扫描电镜研究了茜草科粗叶木属Lasianthus 16种2亚种、1变种及相关的5属5种的花粉形态。粗叶木属的花粉属于广孢型, 单粒。一般中等大小, 绝大多数为圆球形, 少数为近长球形或长球形。花粉形态特征, 特别是在萌发孔和外壁纹饰上表现出多样化。根据孔沟的数目或是否具有内孔, 可以将萌发孔分为(3-)4-(-5)孔沟和3孔。在所观察的这些种中, 萌发孔以3-4孔沟为主要类型, 比例为62.4%。外壁纹饰可分为细网状、粗网状和穴状。有部分种的花粉极面有穴状纹饰, 其余均为网状纹饰。网眼一般椭圆形、近圆形、三角形或者不规则形。少数外壁纹饰网脊上有颗粒状雕纹或模糊的颗粒, 网脊轮廓线呈波浪形, 一般凸出且平滑。大部分种的花粉具有沟膜, 沟膜上具有瘤状突起或小颗粒状, 沟边缘一般较平滑, 或粗糙, 有的种具有沟桥。     

Pollen morphology in the genus Veronica L. (Plantaginaceae) and its systematic significance

Pollen grains of 30, mainly annual, species from 134 populations of the genus Veronica (Plantaginaceae, formerly Scrophulariaceae) from the Mediterranean Region, have been studied with light and scanning electron microscopy. Three pollen types are defined based on pollen size and exine surface sculpture. In some cases within the study group pollen size can be useful in species determination. Hypothetical relationships of pollen grain size and aperture number with ploidy level, style length and corolla diameter are discussed. The ornamentation of the exine in Veronica, although generally a conservative character within the genus, gives some additional support to the most recent infrageneric classification of Veronica.     

Pollen morphology of the genera Polygonum s. str. and Polygonella (Polygoneae: Polygonaceae)

The pollen of 30 taxa (27 species, one subspecies and two varieties) in two genera, viz Polygonum s. str. and Polygonella was investigated with LM and SEM, and some selected taxa with TEM. In all genera investigated the pollen is prolate to spheroidal, and the aperture is mostly tricolporate, rarely panto-hexacolporate (especially Polygonum section Polygonum). The exine sculpturing pattern is the most variable feature. Three types of exine can be recognized. Type 1 (Avicularia-Type, sensu Hedberg) - All species of section Polygonum and section Tephis share the smooth tectate exine with spinules, sometimes the surface is more or less rough (Polygonum afromontanum in section Tephis). Type 2 (Pseudomollia-Type, sensu Hong) - Pollen of Polygonum molliaeforme (section Pseudomollia) has the exine, which is verrucose on both poles and nearby the mesocolpium, and mostly psilate around the ectoaperture. Type 3 (Duravia-Type, sensu Hedberg) - Pollen grains of Polygonum section Duravia and Polygonella have the exine which is semitectate-reticulate at the mesocolpium and the poles, and rugulate/reticulate or sometimes foveolate with microspinules around the ectoapertures. The pollen grains in four taxa (viz Polygonum section Pseudomollia, P. section Duravia and genus Polygonella) have a well-marked dimorphism of the ektexine, which is considered to be a synapomorphic condition. The differences of pollen grain between the genus Polygonella and Polygonum section Duravia are almost non existent and clearly interrelated. It is therefore postulated that the similarity in pollen of both taxa is not the result of convergency, but is interpreted as a homology. It is noteworthy that the pollen of Polygonum molliaeforme (section Pseudomollia) appears as intermediate between the Avicularia-type and the Duravia-type, and is well supported the value of separated section for its own. Additionally, in TEM, some exine ultrastructures (e.g. columellae, foot layer, endexine) appear to be valuable characters for comparison between/among taxa. The systematic potentialities of the pollen data of the studied taxa at various systematic levels are also discussed.     

Pollen and stigma morphology of some Phaseoleae species (Leguminosae) with different pollinators

Pollen transport to a receptive stigma can be facilitated through different pollinators, which submits the pollen to different selection pressures. This study aimed to associate pollen and stigma morphology with zoophily in species of the tribe Phaseoleae. Species of the genera Erythrina, Macroptilium and Mucuna with different pollinators were chosen. Pollen grains and stigmas were examined under light microscopy (anatomy), scanning electronic microscopy (surface analyses) and transmission electronic microscopy (ultrastructure). The three genera differ in terms of pollen wall ornamentation, pollen size, pollen aperture, thickness of the pollen wall, amount of pollenkitt, pollen hydration status and dominant reserves within the pollen grain, while species within each genus are very similar in most studied characteristics. Most of these features lack relationships to pollinator type, especially in Erythrina and Mucuna. Pollen reserves are discussed on a broad scale, according to the occurrence of protein in the pollen of invertebrate- or vertebrate-pollinated species. Some pollen characteristics are more associated to semi-dry stigma requirements. This apical, compact, cuticularised and secretory stigma occurs in all species investigated. We conclude that data on pollen and stigma structure should be included together with those on floral morphology and pollinator behaviour for the establishment of functional pollination classes.     

Pollen grain morphology supports the taxonomical discrimination of Mediterranean oaks (Quercus,Fagaceae)

The exine architecture and some quantitative parameters (polar and equatorial axes and their ratio) of pollen grains allow a clear discrimination between groups of Mediterranean oak species. For the differentiation of species within groups only the quoted parameters prove useful.     

Pollen morphology of the tribe Rhinantheae (Orobanchaceae) and its systematic significances

Pollen morphology of 36 species representing 14 genera within the tribe Rhinantheae in the family Orobanchaceae was studied and illustrated with light microscopy (LM) and scanning electron microscopy (SEM). Five major pollen types were recognized on the basis of exine ornamentation. Within these major types, minor types (subtypes) were distinguished based on exine surface pattern, size, shape, amb form, colpi and colpus membrane. These types and subtypes are as follows: type I. retipilate: subtype Ia. regular retipilate: (1) pollen size < 27 μm, (2) pollen size > 27 μm, subtype Ib. irregular retipilate; type II. verrucate: subtype IIa. macro-verrucate, subtype IIb. verrucate, subtype IIc. sparse verrucate; type III. retirugulate; type IV. granulate; type V. micro-reticulate. A key to pollen morphology of genera studied within the Rhinantheae was made based on pollen morphology from our study and earlier work. Combining with other sources of information on the Rhinantheae, the systematic relationships of this tribe are discussed. Rhinantheae pollen displays considerable variation between genera and species, with taxonomically significant characters at genus and species level. Palynological characteristics provide evidence for interpreting the conflicting views concerning the “Pterygiella Complex”. The evolutionary trend in exine sculpture of Rhinantheae could be proposed, namely that retipilate sculpturing which is the most widespread type is more primitive than the other types (such as foveolate, granulate, regulate, reticulate, retirugulate and verrucate). The pollen data in present study and the view of Hong (1986), as well as the molecular data from Bennett and Mathews (2006) indicated that Asia and related regions were likely to the origin centre of the tribe Rhinantheae.     

Pollen Morphology of Parnassia L. (Parnassiaceae) and Its Systematic Implications

The pollen morphology of 28 species of Parnassia L. was investigated with light microscopy and scanning electron microscopy (SEM). The shape of pollen grains in this genus varies from subspheroidal to prolate in equatorial view and is three-lobed circular in the polar view. Pollen grains are usually radially symmetrical, isopolar, tricolporate or syntricolporate, with reticulate sculpture. The pollen characteristics among species are fairly similar to each other. Morphological information regarding the pollen grains shows that Parnassia is a natural genus. Based on exine ornamentation observed under SEM, three types of pollen grains were recognized: (i) type Ⅰ, with foveolate-reticulate sculpture; (ii) type Ⅱ, with a finely reticulate sculpture; and (iii) type Ⅲ, with a coarsely reticulate sculpture. Most sections of this genus have one type of sculpture of pollen morphology, but Sect. Nectarotrilobos has three types of sculpture and Sect.Saxifragastrum has two types of sculpture. All three types of sculpture can be found in Southwest China,with species with the longest (Parnassia delavayi Franch.) and shortest (Parnassia faberi Oliv.) colpi,implying that Southwest China is the center of diversification of the genus.     

Pollen Morphology of Parnassia L. （Parnassiaceae） and Its Systematic Implications

The pollen morphology of 28 species of Parnassia L. was investigated with light microscopy and scanning electron microscopy (SEM). The shape of pollen grains in this genus varies from subspheroidal to prolate in equatorial view and is three-lobed circular in the polar view. Pollen grains are usually radially symmetrical, isopolar, tricolporate or syntricolporate, with reticulate sculpture. The pollen characteristics among species are fairly similar to each other. Morphological information regarding the pollen grains shows that Parnassia is a natural genus. Based on exine ornamentation observed under SEM, three types of pollen grains were recognized: (i) type I, with foveolate-reticulate sculpture; (ii) type II, with a finely reticulate sculpture; and (iii) type III, with a coarsely reticulate sculpture. Most sections of this genus have one type of sculpture of pollen morphology, but Sect. Nectarotrilobos has three types of sculpture and Sect.Saxifragastrum has two types of sculpture. All three types of sculpture can be found in Southwest China,with species with the longest (Parnassia delavayi Franch.) and shortest (Parnassiafaberi Oliv.) colpi,implying that Southwest China is the center of diversification of the genus.     

Pollen morphology of alpine butterworts (Pinguicula L., Lentibulariaceae)

The pollen morphology of Pinguicula alpina, P. arvetii, P. grandiflora subsp. grandiflora, P. grandiflora subsp. rosea, P. hirtiflora, P. leptoceras, P. poldinii, P. reichenbachiana, and P. vulgaris, belonging to the Alpine flora, was studied.The pollen grains, coming from different populations, were investigated using light microscopy and scanning electron microscopy. The pollen size, the shape (P/E ratio), the number of colpori and the exine ornamentation are, for Pinguicula, important diagnostic characters.Pinguicula pollen grains are medium sized (∼ 30 μm), trinucleate, isopolar, radially symmetric. The shape of the grains is variable from oblate spheroidal to prolate spheroidal and they are (4)-5-9-(10)-zonocolporate. The prevalent ornamentation is rugulate-microreticulate, P. alpina has a rugulate-reticulate ornamentation and only P. hirtiflora has a perforate ornamentation.A pollen key, based on micromorphological data, is presented.     

紫金龙属花粉形态与种子表面特征研究

对罂粟科Papaveraceae国产紫金龙属Dactylicapnos Wall. 4种植物的花粉和种子进行了光学显微镜和扫描电镜观察。该属花粉粒常为近球形,6散沟,花粉粒直径为29.2－50.8。本属植物的花粉有很多共同特征,但种之间有区别。萌发沟清晰(宽果紫金龙D. roylei (Hook. f. et Thoms.) Hutch.),或不清晰(紫金龙D. scandens (D. Don) Hut ch.和丽江紫金龙D. lichiangensis (Fedde) Hand._Mazz.)至模糊     

Phytogeographical data and modern pollen rain of the puna belt in southern Peru (Nevado Coropuna, Western Cordillera)

Aim To improve knowledge of the distribution of species and modern pollen dispersal in the puna vegetation belt (central Andes) for palaeoenvironmental analysis and reconstructions. Location Puna belt, Nevado Coropuna, Western Cordillera, Peru. Methods The vegetation facies and belts of the area were mapped by remote sensing using a March 1998 SPOT4 image. This was complemented by the interpretation of aerial photographs, by field sampling, and by the identification of plants. Data from 1940 to 1994 from the Peruvian meteorological station network were modelled to characterize the relationship between climate and vegetation. Twenty‐four soil‐surface samples were collected in the various vegetation facies identified on the map, and standard palynological techniques were applied to analyse these samples. A principal components analysis was performed on the pollen data set. Results The map shows three bioclimatic belts and seven facies in the puna sensu lato, and identifies the main plants that are characteristic of each bioclimatic area. The pollen results fit the vegetation facies and belts, including the plant species of the distinct facies that are well represented in the pollen assemblages. The mesotropical belt is characterized by the predominance of Asteraceae‐type Ambrosia; the supratropical belt shows significant frequencies of Asteraceae‐type Senecio; the orotropical belt is characterized by high frequencies of Apiaceae and includes Polylepis woodland and peat bogs; and the cryorotropical belt shows significant frequencies of Asteraceae‐type Senecio and Apiaceae. Main conclusions The pollen grains of the plants that grow on the puna sensu lato are generally entomophilous and are therefore not transported far from their plant source. The distinct bioclimatic facies and belts identified by the cartography can thus be well distinguished by their pollen production and deposition. We were therefore able to characterize the relationship between pollen, vegetation and climate that can be used for palaeoenvironmental reconstructions. An altitudinal pollen gradient on the western slopes of the central Andes was revealed by the pollen study, with the succession of Asteraceae‐type Ambrosia (1800–2200 m), Malvaceae (2700–3300 m), Asteraceae‐type Senecio (3500–4100 m) and Apiaceae (above 4600 m).     

中国紫金牛属圆齿组花粉形态研究及其分类学意义

利用扫描电子显微镜对紫金牛属圆齿组20种1变种植物的花粉形态进行了研究,并比较分析了腋序组2种及锯齿组1种的花粉。经观察花粉为近球形或近扁球形,具3孔沟,除锯齿组的月月红外,其余种均形成合沟。外壁纹饰可分为四类:穴网状、细网状、皱波状及细颗粒状(带刺突)。结果显示,花粉形态特征可作为属下分组及组下分类处理的依据。