Studies on Pollen Morphology and Taxonomy of Lespedeza and Its Allied Genera from NE China

The pollen morphology of 11 species and 1 variety in the genus Lespedeza and its allied genera (Campylotropis, Kummerowia) from NE China was examined under light and scanning electron microscopes. 1. Lespedeza Michx. (plate 1:1-6; 2:1-6; 3:1-6; 4:1-2) Pollen grains prolate, rarely subprolate or spheroidal, elliptic or rarely suborbicular in equatorial view, 3-lobed-rounded in polar view, tricolporate, colpus margins smooth or jagged. Polar axis 20.7-33.1μm long, equatorial axis 15.4-20.9 μm long. Exine reticulate or foveolate, lumina verrucose or smooth under SEM. 2. Campylotropis Bge. (plate 4:3-4) One species in NE China, C. macrocarpa (Bge.) Rehd. Pollen grains prolate, elliptic in equatorial view, 3-lobed-rounded in polar view, 3-colporate, colpus linear, 25.1μm long, 1.79μm broad, colpus margins jagged, with a series of verrucae equal in size along one side visible under SEM. Polar axis 19.7μm long, equatorial axis 14.6μm long. Exine reticulate, lumina nearly rounded, verrucose at periphery under SEM. 3. Kummerowia Schindl. (plate 4:5-6) Pollen grains spheroidal, oblate or prolate, elliptic in equatorial view, obtuse-triangular in polar view, tricolporate, colups linear, 25.1μm long, 2.01μm broad, colpus margins sinuate. Polar axis 24.7-27.9μm long, equatorial axis 19.7-26.6μm long. Exine reticulate or subreticulate, lumina nearly rounded, with verrocae visible under SEM. According to the pollen morphology of Lespedeza and its allied genera, the division of Lespedeza (s. lat.) into Lespedeza (S. str.), Campylotropis and Kummarowia by Schindler (1912) is reasonable. The subdivision of Lespedeza (s. str.) into Sect. Macrolespedeza and Sect. Lespedeza by many botanists, and the treatment of Lespedeze juncea (L. f.) Pers. var. inschanica Maxim. as an independent species (i.e. Lespedeza inschanics (Maxim). Schindl.) are also supported by the pollen morphology shown in the present work.     

A Study on Pollen Morphology of Tribe Rhamneae (Rhamnaceae)in China

Pollen morphology of 25 Chinese species, representing 6 five genera in the tribe Rhamneae of Rhamnaceae, was examined under LM and SEM. Pollen grains are subspheroidal or suboblate, obtuse-triangular in polar view, 3-colporate, with the polar axis (P)10.4-28.7μm long and equatorial axis (E) 11.3-30.5μm long, P/E = 0.81-1.11. Colpi generally narrow and long, ora lalongate, with two ends connected with the thinned part of exine, forming a H-shape. Four thickenings were observed where colpi and ora cross, but sometimes the thickenings were indistinct or formed a ring. The stratification indistinct. The ornamentation of exine obscure or indistinctly reticulate under LM, but rugulose, short-striate, rugulose-foveolate or reticulate under SEM. The exine ultrastructure of Rhamnus ussuriensis was examined under TEM. It consists of imperforate tectum, granular layer, foot layer and endexine. The tectum is rather thick with uneven surface, while the granular layer is rather thin. A key to the genera based on pollen characteristics is provided and the general pollenmorphology of five genera, i.e. Sageretia, Rhamnus, Hovenia, Colubrina and Alphitonia, is described respectively. Based on pollen size, the four thickenings and the ornamentation, the five genera under study may be distinguished from each other. For example, pollen grains are smaller in Sageretia; the four thickenings are larger and distinct in Hovenia and Alphitonia. However, the ornamentation is short-striate under SEM in Hovenia and Alphitonia, while reticulate in the Colubrina and Rhamnus ( Subgen. Rhamnus) .Two different concepts of Rhamnus exist among taxonomists. Heppeler and Suessenguth divided Rhamnus into two subgenera (Subgen. Frangula and Subgen. Rhamnus), whereas Grubov separated Subgen. Frangula from Rhamnus as an independent genus. According to the pollen morphology, the separationis reasonable.     

黑龙江省抗寒李资源花粉形态的比较观察

对31个寒地李资源进行了电镜扫描,在测量极轴、赤道轴,条脊宽、穿孔径、穿孔频率后,分析出31个李品种花粉粒大小属于小至中等,31个李品种大多为长球形（比值2～1.14）,个别品种牛心李、长李17号、吉林六号为超长球形（比值>2）, 均有3条沿极轴走向的等间距的发芽沟,发芽沟的有开张、半开张、不开张3种。31个李品种的外壁纹饰可以分为七种类型,大多数李品种的纹饰是条脊平行或分枝多穿孔纹饰,云状纹饰品种少为矮甜李、龙园秋李,脑纹状纹饰只有延吉李。根据极轴、赤道轴、条脊宽、穿孔径、穿孔频率5项指标,采用最远距离法对31个李品种进行聚类分析,牛心李与其它30个李品种亲缘较远。     

A Study on Pollen Morphology of Eucommia ulmoides Oliver

Eucommia ulmoides Oliver is endemic to China. The pollen morphology and exine ultrastructure were examined under LM, SEM and TEM. Pollen grains are prolate, polar axis 30.5-54.8 μm long, with the average 32.7 μm, equatorial axis 27.8-31.3 μm long, with the average 29.2 μm, tricolporoidate, but sometimes the outline of ora could be observed and elliptic in shape. Colpi are narrow, uequal in length, often two long and one short or two short and one long, sometimes rather irregularly arranged, with indistinct and thin colpus membrance. Exine psilate under LM, granulate under SEM, and shortly baculate under TEM. Tectum is thin with dense and small granules, columellae layer consists of short bacules, and foot layer very thick. Some taxonomists (Cronquist, 1968) consider that Eucommiaceae is related to Hamamelidales, but others (Takhtajan, 1969) to Urticales. The Urticales is of the porate type of pollen grains, while Eucommiaceae of tricolporoidate type, and thus the former is more advanced than the latter. Pollen grains of some members of Hamamelidales, tricolporoidate, are similar to those of Eucommiaceae. We therefore consider that Eucommiaceae is related to Hama-melidales.     

我国睡莲科花粉形态的研究

本文对我国睡莲科5属11种2变种的花粉形态进行了系统的研究。每种花粉都通过光学显微镜和扫描电镜进行观察和照相。同时对莲和白睡莲二种花粉作了超薄切片,对它们的外型结构进行了透射电镜的观察和照相。并结合有关分类学和孢粉学资料,讨论了本科的原始性、异质性及演化上的问题。     

中国15种变豆菜属植物的花粉形态及系统学分析

利用光学显微镜和扫描电子显微镜对变豆菜属15种植物的花粉形态进行观察。结果表明,变豆菜属15种植物的花粉大小为（28.51~54.29） μm~（12.23~28.98） μm,极轴与赤道轴比值（Polar axis/Equatorial axis）为1.48~2.46,具三孔沟。花粉粒赤道面观有近矩形、赤道收缩形、长椭圆形等类型,其中近矩形和赤道收缩形占多数;极面观为圆形或三角圆形。在扫描电镜下,其外壁表面纹饰为网状。我们研究结果支持在伞形科变豆菜亚科中,变豆菜属植物的花粉具有中等进化、比较进化的形态特征,花粉形态可为个别物种的分类处理提供孢粉学证据。     

刺五加、无梗五加花粉的亚显微形态学研究

用扫描电子显微镜观察了刺五加和无梗五加花粉的亚显微形态特征。花粉粒的赤道面观呈近圆形,极面观呈三裂圆形,具三孔沟。无梗五加、刺五加雄株的花粉表面纹饰为网状;刺五加两性株的花粉的表面纹饰亦呈网状,但有些花粉网脊不连续。无梗五加的花粉粒大小为26.5μm×27.4μm;刺五加雄株的花粉粒大小为21.1μm×22.1μm;刺五加两性株的花粉粒大小约为21.6μm×23.9μm。研究结果表明,无梗五加和刺五加雄株花粉的亚显微形态特征支持传统的属级和种级水平的分类;刺五加两性株某些花粉粒亚显微形态的独特表现可能与其发育不正常有关。     

中国槲寄生属花粉形态的研究

首次系统地报道中国槲寄生属10种植物花粉形态。通过光学显微镜和扫描电镜观察,国产槲寄生属种类可按花粉的外壁纹饰分为两大类群,与形态上划分相一致。类群Ⅰ(8种)具不显著或近光滑的外壁纹饰,这一类型又可分为2个亚型:纹饰在花粉各个部位基本上是一致的和纹饰在赤道和极、沟两侧不一致的;类群Ⅱ(2种)外壁具显著的杆状纹饰。但花粉性状对形态上相近的种类鉴定意义不大。还讨论了槲寄生属花粉的可能的演化趋势。     

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.     

蜘蛛抱蛋亚族的花粉形态

本文研究并报道了百合科蜘蛛抱蛋亚族的花粉形态,主要结论如下：1．开口箭属含两种花粉类型即：(1)单槽、椭圆形;(2)无萌发孔、球形。具单槽、椭圆形花粉的种类含单型性核型,花形较小,柱头小而花柱短,雄蕊高于柱头;无萌发孔、球形花粉的种类则为单型性核型,花形较大,柱头常高度膨大,雄蕊常着生在花被筒基部。2．万年青属花粉为椭圆形,具单槽;蜘蛛抱蛋属花粉则为球形,无萌发孔;开口箭属花粉一部分与万年青属相似,另一部分则与蜘蛛抱蛋属雷同。3．蜘蛛抱蛋亚族中最原始的花粉类型为单槽椭圆形,具孔状或网状外壁纹饰。球形,无萌发孔,外壁具皱波状、瘤状或芽孢状纹饰的花粉为派生类型。4．蜘蛛抱蛋亚族种下花粉形状、萌发孔类型和外壁纹饰基本稳定,可作为分种特征。     

An Assessment of Pollen Morphology in the Genus Vitex L. (Labiatae)

Pollen grains of Vitex (Labiatae) a large pantropical genus with a few temperate species, are examined by light microscopy, SEM and TEM. All grains are elliptic and tricolpate. However, exine surface sculpture varies between taxa. Two main morphological groups are recognized: the first is tectate simple-perforate to tectate perforate-fenestrate (with perforations anastomosing); the second tectate micro-reticulate/rugulate with micro-perforations in valleys between muri (the latter form is found in Madagascar taxa which have a long corolla tube). Pollen of the commonly cultivated Vitex negundo is unusual in having supra-rugulate, often collapsed grains. Polar and equatorial sizes are included and the possible taxonomic significance of the morphological differences discussed.     

Pollen Morphology in the Subtribe Aspidistrinae (Liliaceae s. l.)

Pollen morphology in the subtribe Aspidistrinae is reported and the main viewpoints are summarized as follows: (1) Two major types of pollen grains, i.e., monosulcate,ellipsoidal pollen and inaperturate, spheroidal pollen, are identified in the genus Tupistra. The species with monosulcate, ellipsoidal pollen usually have monomodal karyotypes, brightcolored flower, smaller stigma, and stamens inserted at upper or middle part of perianth tube, while the inaperturate and spheroidal pollen is always found in the species with bimodal karyotypes, dingy-colored flower, swollen stigma and stamens inserted at the base of perianth tube. (2) Pollen grains in the genus Rhodea are monosulcate and ellipsoidal, while those in the genus Aspidistra are inaperturate and spheroidal, correspondingly similar to the second type of pollen grains in the genus Tupistra. (3) The most primitive pollen in the subtribe Aspidistinae is regarded as monosulcate and ellipsoidal, having perforate or reticulate exine sculpture. The inaperturate, spheroidal pollen with verrucate, gemmate or rugulate exine sculpture is considered derived; (4) Unlike those reported in other groups of the family Liliaceae, the infraspecific pollen shape, aperture type and exine sculpture in Aspidistrinae are basically stable and may serve as a taxonomic character.     

中国柽柳科植物花粉形态的研究

本文用光学显微镜和扫描电镜观察了分布于我国的4属30种柽柳科植物花粉形态。并用透射电镜研究了柽柳属的代表种, Tamarix elongata外壁内部的超微结构。本科花粉为三沟, 少数属种为三拟孔沟。根据扫描电镜观察, 柽柳属花粉外壁表面具粗网状纹饰和细网状纹饰, 以及界于这两个类型之间的过渡类型。水柏枝属外壁表面具粗网状纹饰, 细网状纹饰, 小穿孔以及小的蠕虫状突起。红沙属和枇杷柴属均为细网状纹饰。 本科柽柳属花粉与杨柳科中柳属的花粉特征较相似, 本文提出了它们之间的区别。     

A Study on Pollen Morphology of Some Chinese Genera in Tribe Anthemideae

This paper deals with pollen grains of 9 chinese genera of Trib. Anthemideae Cass., which include the genera: Ajania Poljak., Hippolytia Poljak., Stilpnolepis Krasch., Elachanthemum Ling et Y. R. Ling, Filifolium Kitam., Ajaniopsis Shih, Kaschgaria Poljak., Neopallasia Poljak., Seriphidium Poljak., Pollen grains of these genera are isopolar, radially symmetrical, 3-colporate, NPC 345, spheroidal, sometimes suboblate or subprolate. Polar axis 20.0-30.0μm equatorial axis 20.0 -30.0μm. The exine consists of three layers: tectum, columellae and nexine. Exine thickness 3.2-5.6μm, usually the columellae is the thickest. According to the differences of exine ornamentation, they are divided into two main groups: 1. with distinct spines, including the genera Ajania Poljak., Hippolytia Poljak., Stilpnolepis Krasch., 2.with indistinct spinules, including the genera Elachanthemum Ling et Y.R.Ling, Filifolium Kitam., Ajaniopsis Shih, Kaschgaria., Neopallasia Poljak.,Seriphidium Polj     

POLLEN MORPHOLOGY IN THE GENUS ERYTHRONIUM (LILIACEAE) AND ITS SYSTEMATIC IMPLICATIONS

Pollen morphology was examined in 40 samples from 19 species in the genus Erythronium (Liliaceae) using scanning (SEM) and transmission electron microscopy (TEM). Pollen grains are monosulcate monads, except for a plant of E. oregonum which has dyad grains. North American and European species are characterized by reticulate exine sculpture composed of various degrees of wavy muri and variably-sized lumina. The most distinctive feature of exine sculpture in the genus is exhibited by the Asian species E. japonicum, which has a unique reticulate pattern composed of striate muri and a distinctive exine structure without columellae. The distinctness of E. japonicum pollen suggests that it has specialized in isolation from species in North America and Europe.     

Pollen morphology of the tribe Cynoglosseae of Boraginoideae (Boraginaceae) in China

Pollen morphology of 16 Chinese species representing 7 genera in the tribe Cynoglosseae of Boraginoideae(Boraginaceae) was examined under LM and SEM, and 5 species under TEM. Pollen grains are cocoon-shaped, rarely subprolate, prolate or ovoid, very small, 7～ 15.7μm× 3.5 ~ 13.9 μm in size, P/E = 1.6～2.02; 3-colporate apertures alternate with 3-pseudocolpi, with equatorial endocingulus except those in Bothriospermum; exine surface is usually smooth, with or without perforations in two poles, rarely with tuberculate ornamentation; exine is rather thin and includes ectexine and endexine, while ectexine consists of imperforate tectum, columellae and foot-layer. The tribe Cynoglosseae has many common characters of pollen grains, but there are some differences among genera. A key to the genera is given based on pollen morphology. Bothriospermum, without endocingulus, may be a primitive genus in this tribe, and its pollen morphology is more similar to that of Eritrichieae than to Cynoglosseae, thus it seems more reasonable to put it into Eritrichieae. Solenanthus may be the most advanced genus in the tribe Cynoglosseae for its pollen grains of sub-isopolar and ovoid shape.     

Polarity, aperture condition and germination in pollen grains ofEphedra (Gnetales)

Pollen grain polarity, aperture condition and pollen tube formation were examined inEphedra americana, E. foliata, E. rupestris, E. distachya, andE. fragilis using LM, SEM and TEM. In the characteristic oblate pollen, as seen in situ in the tetrad configuration, the polar axis is the minor one and the equatorial plane runs between the two narrow ends of the microspore. The intine is thick in fresh fixed mature pollen but we have seen no indication of regions having an exceptionally thick intine that could be considered associated with an aperture or apertures. About three minutes after transferring fresh pollen to the germinating medium the ridged exine splits and twists away from the intine and its enclosed protoplast. The shed exine spreads out and curls into a scroll-like configuration that is as distinctive as that of the pollen shape had been but now having the ridges and valleys perpendicular to the long axis. The pollen tube develops, in our experience with more than a hundred germinating pollen grains, near one of the narrow tips of the pollen grain's equatorial plane. The location of the pollen tube initiation probably is related to the position of the tube cell nucleus. The pollen tube starts to grow about one hour after the exine was shed. The pollen tube emerges close to the narrow end (equator) of the gametophyte. This end emerged first as the exine is shed and is opposite to the prothallial cells. The stout pollen tube is c. 10µm in diameter grown in vitro on agar. In our germination medium the stout tube continued to elongate for about 24 hours reaching a length of c. 100 µm. With respect to exine morphology the aperture condition could be considered as inaperturate. The pollen tube, however, is formed in a germination area near one end of the exineless gametophyte.     

The comparative pollen morphology of genera Matricaria L. and Tripleurospemum Sch. Bip. (Asteraceae) in Turkey

Pollen morphology of four Matricaria species and 28 Tripleurospermum species was investigated with light microscopies (LM) and scanning electron microscopies (SEM). Pollen slides were prepared using Wodehouse technique. Measurements were based on 20 or more pollen grains per specimen. For SEM studies, dried pollen grains were transferred on aluminum stubs and coated with gold for 4 min in a sputter-coater. The pollen grains of Matricaria and Tripleurospermum are radially symmetric and isopolar. The pollen grains of the Matricaria are oblate-spheroidal with the polar axes 16.6–31.2 μm and the equatorial axes 18.7–23.9 μm. Tripleurospermum is oblate-spheroidal, suboblate and prolate-spheroidal with the polar axes 15.6–32.2 μm and the equatorial axes 17.7-38.5 μm. The pollen grains of Tripleurospermum are operculate and tricolporate. Matricaria is operculate and usually tricolporate or rarely syncolporate, tricolpate and tetracolporate. The pollen grain of both taxa shows echinate ornamentation. The spines are commonly conical with a broadened base and a tapered apical portion. The spine length varies between 1.8–4 μm in Tripleurospermum and 2.3–3.3 μm in Matricaria. The width of spines varies between 2.8–4.6 μm in Tripleurospermum and 2.4–3.6 μm in Matricaria. Inter-spinal area shows granulate–perforate, reticulate–perforate, rugulate–perforate ornamentations and the tectum surrounding the spine base is micro perforate. Overall exine thickness ranges from 2.8 to 4.8 μm in Tripleurospermum, 3.6 to 5.2 μm in Matricaria. Intine is thicker under pores in Tripleurospermum (0.3–0.62 μm) than in Matricaria (0.6–0.8 μm). Inter-spinal ornamentations, pollen shape and the numbers of perforations at the spin base have been observed as important morphological characters.     

蜘蛛抱蛋属植物花粉形态及系统学意义

用扫描电子显微镜对国产 1 4种蜘蛛抱蛋属植物的花粉形态进行了观察 ,该属植物的花粉形态有长球形和球形 2种 ;外壁纹饰可分为 3大类型 :( 1 )皱波状纹饰 ;( 2 )小芽孢状纹饰 ;( 3)瘤棒状纹饰。它们的演化趋势是 :皱波状纹饰→芽孢状纹饰→瘤棒状纹饰