Study on the Pollen Morphology of the Family Berberidaceae

The pollen grains of 33 species representing 11 genera of the family Berberidaceae, mostly from China, were examined with the light microscope and scanning electron microscope. Their characteritic details can be used for generic diagnosis. A pollen key to the genera based on these observations is presented. Based on the morphology, the pollen grains can be grouped into the following three types: 1. The tetrad pollen type found only in the genus Sinopodophyllum. 2. The spiraperturate pollen type found in the genera Berberis and Mahonia. 3. The tricolpate pollen type found in the genera Diphylleia, Jeffersonia, Nandina, Dysosma, Caulophyllum, Leontice and Epimedium. A diagnostic key to the pollen grains of genera in the Berberidaceae. 1. Pollen grains single 2. Pollen grains spiraperturate .................... Berberis L., Mahonia L. 2. Pollen grains tricolpate 3. Exine with spinose sculpture ........................ Diphylleia Michx. 3. Exine with non-spinose sculpture 4. Exine with striate or striate-reticulate sculpture ...... Jeffersonia Barton 4. Exine with reticulate sculpture 5. Exine around colpus with distinct thickening ........ Nandina Thunb. 5. Exine around colpus without thickening 6. Pollen grains larger (45—50)×(32.5—37.5)μ 7. Colpus with membrane ................ Dysosma R. E. Woodson 7. Colpus without membrane ................ Caulophyllum Michx. 6. Pollen grains smaller (25—550)×(20—527.5) μ 7. Pollen grains prolate-perprolate .................... Leontice L. 7. Pollen grains spheroidal-prolate...Epimedium L., Podophyllum L. 1. Pollen grains tetrad ............................ Sinopodophyllum Ying     

国产爵床科山牵牛属6种、叉柱花属和老鼠簕属各1种植物的花粉形态

报道了国产爵床科Acanthaceae山牵牛属Thunbergia(山牵牛亚科Thunbergioideae)6种、叉柱花属Staurogyne(瘤子草亚科Nelsonioideae)和老鼠簕属Acanthus(老鼠簕亚科Acanthoideae)各1种植物在扫描电镜下的花粉形态。山牵牛属植物的花粉粒为圆球形,均具螺旋状萌发孔,外壁纹饰以光滑或颗粒状为主,偶具棒状突起。具螺旋状萌发孔被认为是该科独特而较原始的花粉特征。叉柱花属的花粉粒为圆球形,具3孔沟,外壁平滑。老鼠簕属的花粉粒为长球形,具3沟,外壁具细网状纹饰或具小穿孔。花粉形态特征支持传统上将上述3属置于3个不同亚科的处理。     

早发生胚水稻小孢子发生及花粉的萌发生长

实验结果表明,早发生胚水稻（PDER）品系小孢子的发生发育与常规水稻品种相同,常规I-KI镜检显示其成熟花粉育性达87．4％．开花后,少量花粉在柱头上能正常萌发,并以短管形式进入柱头．大部分花粉在柱头上发生了异常行为：不萌发花粉管,但排放出大量内容物;花粉管细小或畸形;在枝头内或柱头外花粉管前端破裂;花粉管在柱头上绕行不进入柱头;花粉管在柱头内逆行生长;花粉管进入柱头后又穿出柱头;花粉管壁上粘有颗粒或被有一层膜等．文中就PDER的来源讨论了这些现象,并提出“萌败”这一新概念．     

东北杜鹃花属植物花粉形态的研究

利用光学显微镜和扫描电子显微镜对东北杜鹃花属(Rhododendron Linn.)6种, 1变种, 1变型的花粉形态进行了观察和比较研究。该属花粉粒均为四合花粉。四合花粉呈正四面体排列。花粉粒近球形。每粒花粉均具3沟,在四合花粉粒上,相邻花粉粒上的沟相接,有些种可见沟内的萌发孔。光镜下可见花粉外壁为内外两层,厚度约相等。不同的种在花粉粒大小上有区别。在扫描电镜下观察可见不同的种花粉表面具有不同的纹饰。即该属在花粉形态上具有种的特性。     

东北杜鹃花科4属植物花粉形态的研究

利用光学显微镜和扫描电子显微镜对东北杜鹃花科甸杜属(Chamaedaphne Moench.)、杜香属(Ledum Linn.)、松毛翠属(Phyllodoce Salisb.)、越橘属(Vaccinium Linn.)4属6种, 1变种的花粉形态进行了观察和比较研究。以上4属花粉粒均为四合花粉。四合花粉呈正四面体排列。花粉粒近球形。每粒花粉均具3沟,在四合花粉粒上,相邻花粉粒上的沟相接,有些种可见沟内的萌发孔。光镜下可见花粉外壁为内外两层,厚度约相等。不同属种的花粉粒在大小上有区别,花粉粒平均直径为34.0~43.7μm。在扫描电镜下观察可见不同的种花粉表面具有不同的纹饰。为分类学提供了孢粉学方面的证据。     

A study on the allergenicity and ontogeny of Acacia farnesiana pollen grains in guinea pigs

Pollen grains as the angiosperm male gametophytes transfer male genetic material during sexual reproduction. Pollen grains are among the important plant allergens, such that almost 80–90 % of plant allergens are of pollen origin. Acacia farnesiana is a plant with economical values, and due to its resistance to dry climates, it has had a widespread distribution in Southern Iran. This study was aimed at investigating the allergenicity and the ontogeny of pollen grains of A. farnesiana. Pollen grains were collected from the blossoms and flowers of A. farnesiana in the suburbs of Ahvaz-Iran. Pollen extracts (15 %) were prepared in PBS (pH 7.2). 4–6-week-old male guinea pigs (Hartly) were used for allergenicity tests. Skin tests showed a significant increase in flare diameter. Clinical tests also showed a significant change in the levels of eosinophils, neutrophils, and IgE. Histotechnical analysis was performed on male gametophytes, and photographs were taken using a camera-equipped light microscope. Pollen characteristics were identified using both light and electron microscopy. Sporoderm ultrastructure and pollen morphology were studied using Scanning Electron Microscopy. PAGE analysis of the total protein content of mature pollen grains showed seven clear bands of 10–83 kDa.     

茨藻科、角果藻科植物花粉形态的研究

在水生植物茨藻目中,茨藻科Najadaceae和角果藻科Zannichelliaceae植物由于其结构、尤其是花部结构的极度简化和趋同适应,系统关系仍不清楚。本文应用光学显微镜、扫描电镜和透射电镜对上述2科4属的10种代表植物的花粉形态进行了观察,系统描述了各属、种的花粉形态。结果表明角果藻科植物花粉均无萌发孔,外壁纹饰通常为拟网状至浅网状。花粉形态的研究结果支持将Vleisia作为角果藻属Zannichellia的近缘属处理的观点。茨藻科植物花粉外壁光滑、稍皱波状或为疣状,具颗粒状纹饰,萌发孔的有无在种间存在变异。花粉形态的研究结果表明角果藻科与眼子菜科Potamogetonaceae近缘,茨藻科可能与水蕹科Aponogetonaceae或水鳖科Hydrocharitaceae中具单沟花粉的类群有一定联系,而与角果藻科和眼子菜科则相去甚远。     

Lessingianthus (Vernonieae–Asteraceae): generic and infrageneric relationships based on pollen morphology

Pollen morphology of 31 species of Lessingianthus was investigated in order to evaluate the generic and infrageneric relationships of Lessingianthus and related genera. Acetolyzed pollen grains were measured, described and illustrated using light microscopy. Non‐acetolyzed pollen grains were investigated using scanning electron microscopy. Pollen grains of Lessingianthus are isopolar monads, suboblate, oblate spheroidal or prolate spheroidal, lophate (30, 29 and 27 lacunae), with small or large polar area, tricolporate. Pollen grains with 30 lacunae occur in the majority of the species examined, and show three apertural, six abapertural, twelve parapertural, six interapertural and three equatorial lacunae. Pollen grains with 29 lacunae occur in L. desertorum, L. simplex and L. virgulatus and are characterized by three apertural, six abapertural, twelve parapertural, six interapertural and two polar lacunae, and by absence of equatorial lacunae. Pollen grains with 27 lacunae occur in L. adenophyllus and L. durus and are characterized by three apertural, six abapertural, twelve parapertural and six interapertural lacunae, but lack polar and equatorial lacunae. Species of Lessingianthus subgen. Lessingianthus, with few exceptions, have pollen grains with type B lophate pattern, which differs mostly in shape. Pollen grains of Lessingianthus subgenus Oligocephalus share a very similar pattern of 29 lacunae with those of Chrysolaena, supporting recently proposed taxonomic changes. Pollen grains with 27 regular lacunae occur in Lessingianthus durus and L. adenophyllus, but the first differ from the latter by having cross muri enclosing the apertural lacuna (type G pollen).     

Pollen size in Carex: The effect of different chemical treatments and mounting media

Pollen size and pollen aperture size for ten species of the genus Carex L., native to Estonia, have been measured using light microscopy. The species selected represent different sections of the genus, a range of habitats and different chromosome numbers. The effects of two basic chemical treatments, two mounting media and the effect of chemically induced dehydration with tertiary butyl alcohol (TBA) on the size of pollen grains were then recorded.

In general pollen size and pollen aperture size of the species examined is highly variable at both intraspecific and interspecific levels. Carex hirta has notably larger pollen grains than any of the other species investigated and, although correlations between size and chromosome number in the species examined are limited, it also has the highest chromosome number. Statistically significant size differences resulted from variations in chemical treatment, mounting media and tertiary butyl alcohol (TBA) induced dehydration. Acetolysed pollen grains are larger than potassium hydroxide (KOH) treated pollen grains. Pollen grains dehydrated after chemical treatment with TBA are larger than pollen grains not dehydrated. Pollen grains mounted in silicon oil are smaller than grains mounted in glycerine. But considering the great size variation of Carex pollen grains, the size changes caused by preparation procedures fall within the size variation range of the species examined.

All the samples contained a high number of deformed pollen grains and pollen grains with hardly distinguishable or no lateral apertures.     

From the anther to the proctodeum: Pear (Pyrus communis) pollen digestion in Osmia cornuta larvae

Modifications of the pollen grains of Pyrus communis Linneaus that occur during the digestion by Osmia cornuta (Latreille) larvae were studied histochemically. We compared the features of the pollen grains found in the anthers, in the larval cell provisions and in the alimentary canal of the 5th instar larvae. Modifications were already evident in the provisions and consisted of protoplast protrusions through the apertures and a decrease in the number of starch-containing pollen grains. After pollen grains were ingested by the larvae, the protoplast appeared retracted from the pollen wall. Pollen digestion began in the anterior part of the midgut, where we observed: (1) disorganised intine at the apertures; (2) disappearance of DAPI staining of nuclear pollen DNA; (3) fewer pollen grains containing starch than in the anthers; (4) some empty pollen grains. Pollen grains in the proctodeum appeared extremely compressed and crushed. Some grains appeared to be unaffected by the digestive process. We hypothesise that the protrusion of the intine and of the protoplast from the apertures in bee provisions could be considered a kind of pre-treatment necessary to initiate the digestion process in the larval alimentary canal.     

Pollen Morphology of the Family Zingiberaceae in China—Pollen Types and Their Significance in the Taxonomy

Pollen morphology of 89 species and 3 varieties belonging to 18 genera (out of 150 spcies in 20 genera) of Zingiberaceae in China was studied under both light microscope and scanning electron microscope. Pollen grains of Zingiberaceae are spherical, subspherical, ovoid and prolate, 36-225 μm in size, nonaperturate or aperturate (spiraperturate, porate). Pollen grains are almost not resistant to acetolysis. The wall is composed of a very thin exine and a thick intine. The exine is psilate, spinate, cerebelloid-areolate, striate, verrucate and foveolate. According to the presence or the absence of aperture and differential ornamentations, two types and six subtypes are recognized: I. The type Nonaperturate: (85 species and 3 varieties in 18 genera). Four subtypes can be recognized within the type based on the characteristics of the exine sculpture. These are: (1) The subtype Psilate, in which, the exine is nearly smooth (including: Hedychium, Curcuma, Kaempferia, Caulokaempferia coenobilis, Boesenbergia rotunda, Stahlianthus, Amomum compactum, Etingera, Hornstedtis, Rhynchanthus). (2) The subtype Spinate, which comprises two groups: (A) The group Short-spinate, pollen grains with smaller spines (Globba), (B) The group Long-spinate, pollen grains with longer spines (Alpinia, Amomum, Plagiostachys, Roscoea, Cautleya, Boesenbergia fallax, Caulokaempferia yunnanensis). (3) The subtype Cereblloid-areolate, pollen grains of which are spherical or subspherical, with cerebelloid sculpture (Zingiber Sect. Zingiber). (4) The subtype Striate, pollen grains of which are prolate or oliveshaped, and striate (Zingiber Setc. Cryptanthium). II. The type Aperturate, in which pollen grains are acetilysis-resistant and possess distinct apertures (mixed colpate-porate or forate), including two subtypes: (1)The subtype Mixed colpate and Porate. Pollen grains are both 3-colpate and 1-3-porate, and usually with one long spiral, two short (straight or slightly curved) colpi and 1-3-poris. The exine is verrucate or not, nearly sinuolate (Costus speciosus, C. tonkinensis, C. lacerus). (2) The subtype porate, whose grains are 6-8-porate and exine is foveolate (Costus megalobractea). The taxonomic significance of the pollen types in the family Zingiberaceae is also discussed.     

Pollen Morphology of the Aceraceae

Pollen of 40 Acer taxa and one species of Dipteronia were examined by light, scanning and transmission electron microscopy. Pollen grains in both genera are tricolpate or tricolporate of prolate to nearly spheroidal shape. Based on sexine pattern, four major pollen types were recognized and include striate grains, rugulose grains, microreticulate grains, and granular grains. Although the family appears to be rather stenopalynous, several useful taxonomic variations occur.     

Pollen morphology of the family Cistaceae in Egypt and its systematic significance

The pollen morphology of 11 species (including two subspecies and two varieties) belonging to two genera (Helianthemum and Fumana) of the family Cistaceae in Egypt was studied using light and scanning electron microscopy.Pollen grains of the studied taxa were found to be radially symmetrical and tricolporate.Pollen size,shape,apertures,and exine ornamentation characteristics were valuable parameters among the studied taxa.The largest pollen size was recorded in H.salicifolium and the smallest one observed in H.kahiricum subsp,schweinfurthii.Pollen shape in the Egyptian taxa varied from (sub-)prolate to prolate spheroidal,but F.arabica is different in having sub-oblate grains.The pollen data confirm that H.lippii and H.sessiliflorum are very closely related species.Pollen sculpture was useful in distinguishing between H.vesicarium var.vesicarium and H.vesicarium var.ciliatum.Three main pollen types of exine ornamentation were recognized:retipilate; reticulate to verrucate; and striate.Based on palynological data,a key for the studied taxa is suggested.     

Pollen Morphology of the Subtribe Hyoscyaminae (Solanaceae)

The pollen morphology of 12 species representing 6 genera was examined under the light; scanning and transmission electron microscope. According to form of aperture; sculpture and structure of exine; the palynological relationships among the 6 genera are discussed. 1. Scopolia Jacq. (plate 1:1-4) Pollen grains subspheroidal or irregular; 43.7-49.6 μ in diameter; nonaperturate; Exine about 1.2-1.5μ thick; verrucate; with verrucae unequal in size; spinulose or granular. Stratification indistinct; with no columella layer visible under TEM. 2. Anisodus Link et Otto (plate 1: 5-12) Pollen grains subspheroidal; 43.4-48.7 μ in diameter; nonaperturate. Exine 1.5-1.8 μ thick; verrucate; with verrucae unequal in size; spinulose or smooth. Stratification indistinct under TEM. 3. Atropanthe Pascher (plate 2: 1-4) Pollen grains subspheroidai or spheroidal; triangular-circular in polar view; oblong in equatorial view; 47.2-49.3 μ ×39.8-47 μ; 3-colpate; colpi wide or narrow; colpus membranes finely granular. Exine with irregular short-stick sculpture; 2.3μ thick; distinctly 2-layered; columella layer clearly visible; sexine thicker than nexine under TEM. 4. Przewalskia Maxim. (plate 2: 5-8) Pollen grains subspheroidal; triangular-circular in polar view; oblong in equatorial view; 39.2-40.3 μ × 36.4-42.8 μ ; tricolporate; ora lalongate; colpus membranes granular. Exine reticulate; 2-layered; 2u thick; columella layer distinct; sexine and nexine equal in thickness under TEM. 5. Physochlaina G. Don (plate 2: 9-12; plate 3: 1-12) Pollen grains polymorphic; usually subspheroidal; 36.5-39.4μ in diameter; aperture varying from nonaperturate (P. macrophylla); 3-4 rugose (P. physaloides) to 3-colporate (P. praealta). Exine 1.5-2μ thick; reticulate; smooth or with spinulose or verrucous processes under SEM; distinctly 2-layered; or without stratification; columella layer differentiated or not. 6. Hyoscyamus Linn. (plate 4: 1-9) Pollen grains subspheroidal; circular-triangular in polar view; oval in equatorial view; 39.9-41.8 μ × 38.7-4.2 μ; tricolporate. Ora orbicular; colpus membranes finely granular or with striate processes. Exine reticulate or striate-rugulate; 2-2.3μ thick; distinctly 2-layered; columella layer developed. The dendrogram (Fig. 1) indicates probable phylogenetic relationships among the sixgenera in the subtribe Hyoscyaminae.     

Generic delimitation of Gochnatia,Richterago and Ianthopappus (Compositae-Mutisieae) based on pollen morphology

Pollen grains of 20 taxa from Gochnatia , Ianthopappus , and Richterago (Compositae - Mutisieae) have been studied. Pollen morphological characters and intergeneric differences are described. Pollen of grains of Richterago and Ianthopappus are relatively larger with thickened exine in the mesocolpia and possess coarse, supratectal spinuliferous processes the height of which is less than their diameter at the base. In Gochnatia , the pollen is medium-sized, the exine is not thickened in the mesocolpia and has minute supratectal spinuliferous processes the height of which is equal or slightly more than 3 w m. Ianthopappus corymbosus is the only species in which the infratectum is thicker than the tectum. With reference to the pollen size and the exine thickness this species appears phylogenetically closer to Richterago than to Gochnatia .     

Pollen morphology of the genus <Emphasis Type="Italic">Skimmia</Emphasis> (Rutaceae) and its taxonomic implications

Pollen morphology of the genus Skimmia was studied. Of six species of the genus, five species were investigated by light microscopy and scanning electron microscopy. Pollen grains of Skimmia had striate to striate-reticulate sculpture and variable aperture number (3-7), and these characters differed from even the phylogenetically closest relatives such as Dictamnus and Casimiroa which have 3-colporate pollen grains with reticulate exine. In Skimmia laureola, pollen dimorphism is suggested in the aperture number in accordance with the floral system. Pollen grains of Skimmia japonica, a morphologically very variable species, were extensively surveyed covering its whole distribution area. The grains were also striate to striate-reticulate, and the exine sculpture was not different between varieties. However, the aperture number of S. japonica showed a geographical variation ranging from 4 to 6; in Sakhalin, Hokkaido, most part of Honshu and Taiwan, grains with 4-5 apertures were dominant, while in the southern part of Japan, including the Ryukyu Islands and the Izu Islands, those with 5-6 apertures were common.     

Pollen morphology and germination inNarcissus

Pollen grains of several species and varieties ofNarcissus were examined with a light microscope and a scanning electron microscope. Normal pollen grains were kidney- or spindle-shaped with a germination furrow and a reticulate structure similar to that of the pollen grains ofAmaryllis. Pollen grains germinated within 2 to 3 hr. Percentage of germination was dependent upon temperature and treatment. Pollen tubes grew in length up to 1,000 μm and branched occasionally or behaved in strange fashion. Fresh pollen grains germinated more in distilled water at lower temperature than in sucrose-aqueous medium. Both in the presence and in the absence of stigmatic exudate calcium increased the percentage of germination. Gibberellic acid, abscisic acid and coumarin inhibited the pollen germination. Plasmoptysis occurred in all species and in all media tested except in a medium containing coumarin without stigmatic exudates. Plasmoptysis did not seem to be induced by hypotonic medium alone. Pollen of high germination capacity showed a high percentage of plasmoptysis. Based on the results obtained, evolution and sterility of theNarcissus plant was discussed.     

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     

Responses of tobacco pollen to high humidity and heat stress: viability and germinability in vitro and in vivo

Summary Responses of pollen grains of Nicotiana tabacum to high humidity (95% RH, 4 h) and temperature (38°/45° C, 4 h) stresses were investigated. Pollen grains were subjected to only RH or only temperature, or to both of these stresses. Their viability was assessed on the basis of the fluorochromatic reaction (FCR) test, and vigour was assessed on the basis of the time taken for in vitro germination as well as on the emergence of pollen tubes through the cut end of semi-vivo implanted styles. None of the stress conditions affected pollen viability and high RH or high temperature stress did not individually affect pollen vigour. However, pollen vigour was markedly affected when both the stresses were given together. Pollen grains subjected to high RH at 38° C took a longer time to germinate in vitro and the pollen tubes emerged later from the cut end of the semi-vivo styles; division of the generative cell was also delayed. Pollen grains subjected to high RH at 45° C failed to germinate in vitro, but did germinate on the stigma. Many pollen tubes subjected to this treatment showed abnormalities, and the growth of pollen tubes in the pistil was much slower than that observed in other treatments. Pollen samples subjected to all of the stress conditions were able to induce fruit and seed set. The implications of these results on the relationship between the FCR test and viability, and between viability and vigour, especially in stressed pollen, are discussed.     

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.