Pollen morphology of the subtribe Cuspariinae (Rutaceae)

The neotropical subtribe Cuspariinae (Rutaceae) comprises as many as 26 genera and over 125 species. Pollen grains from 111 collections representing 71 species and 24 genera were examined by LM, SEM, and TEM. The pollen morphology of this subtribe is very diverse. Grains are mostly 3–6-aperturate and colporate, rarely porate (Spiranthera) or pantocolporate (Almeidea). Exine sculpturing is most commonly reticulate, sometimes perforate, foveolate-perforate, foveolate, foveolate-reticulate, reticulate, striate-reticulate, echinate, clavate, or baculate. The exine structure is columellate and tectate-perforate, columellate and semitectate, or intectate and is stratified into ektexine and endexine. The exine ofLeptothyrsa is distinctive in that the ektexine of the mesocolpium is longitudinally deeply ridged. The pollen ofHortia, characterized by a psilate exine with rare perforations, a very thick foot-layer, and reduced columellae, is unlike that of any member of the Cuspariinae and offers no support for the transfer of this genus from the Toddalioideae. The pollen data correlate with macromorphological characters and are taxonomically useful.     

紫草亚科附地菜族的花粉形态研究

本文用光学显微镜和扫描电子显微镜系统观察了附地菜族5个属26种植物花粉形态。五属是附地菜属、车前紫草属、滨紫草属、山茄子属和皿果草属。观察证明属间花粉形态有明显的差异。花粉资料为族内属的划分和皿果草属的建立提出了花粉学证据。     

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 Gardenieae-Gardeniinae (Rubiaceae)

Pollen grains of 107 species of 61 genera of the Gardeniinae were investigated by scanning electron and light microscopy. The subtribe is europalynous and grains occur either as monads, tetrads or massulae. Grains are porate, colporate or rarely pororate. The majority of the genera has 3-zonoaperturate pollen grains. However, deviating numbers of apertures occur in Byrsophyllum (4–8) and Pseudomantalania (4–5). Pantoporate pollen occurs in Randia . The average equatorial size (E) of monads varies between 13 μm in Anomanthodiu to 59 μm in Posoqueria . The tetrads vary from 37 μm in Casasia to 61 μm in Calochone and Euclinia . The exine is usually reticulate, but also foveolate, rugulate, perforate and psilate exine occurs in the subtribe. The thickness of the exine is only 0.3 μm in tetrad grains of Randia armata and in the pantoporate monad grains of R. ruiziana , whereas the thickest exine occurs in Posoqueria (2.8 pm) and Euclinia (2.9 μm). Tectal excrescenses are generally absent. However, three genera with pollen in tetrads, namely Euclinia, Gardenia and Oligoco-don , show this feature. Contrary to the subtribe most genera are fairly stenopalynous, but in the neotropical genera Alibertia and Randia several different types of pollen are encountered.     

Pollen characteristics of the tribes Calycophylleae, Cinchoneae, and Hillieae (Rubiaceae)

Pollen grains were studied on acetolysed material with the aid of the SEM. They may be classified into four types. Type I is characterized by thick (0.92.1 μm) exine with reticulate surface, by distinct colpi with acute ends, and by distinct ora. It occurs in the genera Alseis, Calycophyllum, Ferdinandusa , and Schizocalyx. Ferdinandusa is further characterized by its lumina being differentiated into two distinct size classes. Type II is characterized by a usually thin (usually 0.7–1.1 μm) exine with foveolate surface, by distinct colpi with obtuse to truncate ends, and by poorly demarcated ora. It occurs in Cinchona, Joosia, Ladenbergia , and Remijia . Pollen grains of Joosia are mostly 4–colporate. Type III is characterized by a thick (1.7–2.0 μm) exine with coarsely reticulate surface, colpi are lacking or short and the ora are clearly demarcated. It occurs only in Capirona . Type IV is characterized by a thin (0.5–0.8 μm) exine with a psilate or foveolate surface and usually indistinct colpi with obtuse ends, and by distinct ora. It occurs in Cosmibuena and Dolicholobium . Pollen grains of Balmea, Hillia, Macrocnemum, Stilpnophyllum , and Wittmackanthus , combining features of Type I and II, do not fit into either of these four groups. It is concluded that both the tribes Calycophylleae and Cinchoneae remain eurypalynous in spite of a recent emendation. It is suggested that pollen characters serve best to characterize genera and small groups of genera. It is further suggested that Type I pollen is plesiomorphic in most or all characteristics.     

Pollen morphology inParis and its related genera

Pollen grains ofParis, Medeola, andScoliopus have been examined with light, scanning electron, and transmission electron microscopies.P. quadrifolia L.,P. verticillata Bieb.,P. delavayi Franch. andP. polyphylla Smith have monosulcate pollen characterized by psilate, foveolate or reticulate exine sculpture. In contrast to the former species,P. japonica (Fr. et Sav.) Franch. andP. tetraphylla A. Gray have monosulcate pollen with gemmate (rarely rugulate) exine.Medeola has monosulcate pollen with reticulate exine that is distinct from that ofParis. Scoliopus has monosulcate pollen characterized by a peculiar reticulate exine pattern. The palynological evidence suggests thatParis andTrillium are closely related to each other, andMedeola andScoliopus should be separated fromParis andTrillium.     

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。     

Pollen morphology and ultrastructure of the Bennettitales: In situ pollen of Cycadeoidea

The micromorphology and ultrastructure of in situ pollen from Cycadeoidea dacotensis are described from permineralized specimens collected from the Lower Cretaceous of North America. Pollen grains are ovoid and relatively small, averaging 25 μm in length and 12 μm in width. Grains are monosulcate with the exine typically invaginated in apertural regions. Exine ornamentation ranges from punctate to psilate. The exine averages 0.73 μm in thickness and is composed of a light-staining sexine and a dark-staining nexine. The sexine consists of a thin, homogeneous tectum, typically with a well-defined inner boundary, and a thicker granular infratectum. The infratectal granules are relatively uniform in size, however, variation occurs in the arrangement of granules. In some grains, the sexine appears homogeneous because there is little lacunal space between the individual granules. The granular infratectum is in direct contact with the underlying nexine. The nexine is uniform in thickness in both apertural and nonapertural regions, and it lacks lamellae throughout. Pollen morphology and ultrastructure are compared with those of the bennettitalean genus Leguminanthus and the dispersed genus Monosulcites. In addition, the fine structure of Cycadeoidea pollen is compared to that of the gymnosperm groups with which the Bennettitales are regarded to be most closely related, including Gnetales, Pentoxylales, and Eucommiidites-type pollen-producing plants.     

THE ULTRASTRUCTURE OF SAHNIA POLLEN (PENTOXYLALES)

The micromorphology and fine structure of in situ pentoxylalean pollen are described from the holotype of Sahnia laxiphora Drinnan and Chambers 1985 collected from the Lower Cretaceous (Valanginian-Aptian) of Victoria, southeastern Australia. Pollen grains are ovoid, monosulcate, and relatively small, averaging 26 μm in length. Exine ornamentation is psilate. The sporoderm is two-parted with the sexine staining lightly throughout and approximately six times the thickness of the more darkly staining nexine. The exine over the sulcus is typically strongly invaginated, and may or may not include an extremely thin sexine layer. The outer part of the sexine is homogeneous, while the inner part is composed of relatively large granules separated by irregular lacunae of various sizes; lacunae are most pronounced at the sexinenexine interface. Faint lamellae characterize the nexine in both apertural and nonapertural regions. Granular orbicules are often associated with the exine surfaces and also occur appressed to pollen sac walls along with lamellated tapetal membranes. Sporoderm ultrastructure is compared to that of nonsaccate pollen of other groups, and particularly to pollen of Bennettitales, Gnetales, angiosperms, and similar plants, to which the Pentoxylales have been thought to be closely related. Although Sahnia laxiphora pollen is not identical to that of any of these taxa, the strongest similarity is with pollen of Bennettitales.     

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 Morphology of Ribes L. and Its Taxonomic Significance

The pollen morphology of 19 species and 2 varieties in the genus Ribes Linn. was examined under light microscope (LM) and scanning electron microscope (SEM). Pollen grains of the genus are subspheroidal, 15.0-41.67 μm in diameter, more or less circular to obtusely quadrangular in outline with all sides slightly concave, or with alternating concave sides, or elliptic under SEM, 5-, 6-zonocolporate or 5-, 6-pantoporate. Exine usually thin, 1.0-1.5μm, without visible differentiation between nexine and sexine. Exine is psilate or sometimes coarsely or finely granular or verrucate. The most important characteristic of pollen in this genus is the presence of a “rugoid Area” (ectoaperture) around the endoaperture under SEM. It is different from the other taxa of Saxifragaceae (s. 1.). Based on the pollen morphology and the external morphological characteristics, the treatment of the genus Ribes as an independent family (i.e. Grossulariaceae) by many taxonomists is reasonable. The pollen grains of the genus can be divided into 4 types from the materials examined: (1) Grossularia-type. ectoaperture colpate, with two endoapertures, exine psilate. (2) Ribes-type: ectoaperture porous or colpate, with one or two endoapertures, exine mostly psilate. (3) Grossularioides-type: ectoaperture porous, circular, small, with one endoaperture, exine verrucate. (4) Berisia-type: ectoaperture porous, subcircular to circular, large, with one endoaperture exine mostly psilate. The observation made by the present authors supports the subdivision of Ribes into the subgenera Grossularia, Ribes, Grossularioides and Berisia by many taxonomists based on the other morphological characteristics, and the observation by the present authors is in accordance with this view. Pollen information also shows the close relationships among thefour subgenera and therefore they belong to the same genus — Ribes.     

Palynological variation in balsaminoid ericales. I. Marcgraviaceae

BACKGROUND AND AIMS: Marcgraviaceae are a rather small family of seven genera and approx. 130 neotropical species. This study aims to present a detailed palynological survey of the family in order to comment on the intrafamily relationships and possible correlations with pollinators. METHODS: In total, 119 specimens representing 67 species and all genera are observed using light microscopy and scanning electron microscopy. Furthermore, eight species from five genera are studied with transmission electron microscopy. KEY RESULTS: Our results show that pollen grains of Marcgraviaceae are small (20-35 microm), have three equatorial apertures, granules on the colpus membrane, oblate spheroidal to prolate spheroidal shapes, mainly psilate to perforate ornamentations, and lalongate colpus-shaped thinnings at the inner layer of the exine, and show the presence of orbicules. Based on our fragmentary knowledge of the pollination biology of the family, there are no clear correlations between pollinators and pollen features. CONCLUSIONS: The genus Marcgravia has a high percentage of reticulate sexine patterns and a relatively thin nexine. Sarcopera can be defined by the presence of an oblate spheroidal to even suboblate shape, while Ruyschia and Souroubea typically show prolate spheroidal to subprolate pollen grains. The presence of a thick foot layer in the pollen wall is characteristic of the genera Norantea, Sarcopera and Schwartzia. Pollen features that are taxonomically useful within the family are the shape, sexine sculpturing, and ultrastructure of the pollen wall.     

Pollen Morphology of Microula Benth. and Allied Genera (Boraginaceae)

Pollen grains of 16 species of Microula Benth. and six species of three related genera were examined under LM and SEM, and four of them also under TEM. Pollen grains of Microula and three related genera are dumb-bell-shaped, 3-colporate apertures alternate with three pseudocolpi. Pollen grains are very small,ranging from 12.18 x 7.13 μm to 6.36 x 3.66μm. In general, colpi with os are wider and shorter, rhomboid, but sometimes they are equal to pseudocolpi in length. Colpus margins are regularly or irregularly tooth-like. The surface of colpi is psilate or processed. Ora are circular or lalongated in outline, protruded or not; surface of os membrane is smooth or scabrid. The exine is usually indistinctly layered under LM. The exine surface is psilate, and more or less perforate. TEM examination shows that the pollen wall is differentiated into exine and intine: the exine includes ectexine and endexine, while the ectexine consists of tectum, columellae and foot-layer. However, there are differences in constriction of equatorial area, apertural characters, ornamentation and exinous ultrastructure between these genera. Pollen morphology indicates that the genus Microula Benth. is primitive, directly related to the genus Actinocarya Benth .; the genus Asperugo L. Is more advanced. The genus Eritrichium Schrad. which has two ora or one os and is anisopolar, represents the most advanced group among them. Noteworthily, the diorate phenomenon is found for the first time not onlyin the genus but in the family Boraginaceae.     

POLLEN MORPHOLOGY AND SYSTEMATIC RELATIONSHIPS AMONG NEW WORLD SPECIES IN TRIBE ANTIRRHINEAE (SCROPHULARIACEAE)

The morphology of mature pollen grains among 12 New World genera in tribe Antirrhineae has been examined with light and scanning electron microscopy. Pollen from 29 American species have mean polar diam that range from 17 to 26 μm, have a tectate structure with perforate, microreticulate, or reticulate surface pattern, and are subspheroidal to prolate, and trizonocolporate with fusiform or narrowly oblong colpi that are free or occasionally fused at the poles. Among the genera, pollen size is positively associated with style length but not haploid chromosome number. Three major morphological categories are recognized based on grain shape, exine structural pattern, and colpus shape. Two of these morphotypes each characterize individual genera (Mohavea, Linaria). The other morphological category includes ten New World genera and has been divided into three subcategories based on variation in lumina diam and intermittent occurrence of fused colpi. Only Antirrhinum and Pseudorontium have species or populations with pollen in more than one subcategory. Concordance of morphological, anatomical, chromosomal, and palynological data suggests that Linaria and Mohavea are best placed in separate subtribes from other native American genera. Compared to Old World taxa in tribe Antirrhineae, the most common pollen type (subspheroidal, microreticulate, apocolpate, fusiform colpi) may be the most primitive. Pollen grains with fused colpi (Antirrhinum p.p., Pseudorontium) and perforate (Mohavea) or reticulate (Holmgrenanthe) structural patterns probably represent derived types.     

大风子科13个种的花粉形态

利用光镜和扫描电镜对大风子科 9属 1 3个种的花粉形态进行了观察。花粉形状长球形或圆球形 ,除大风子属 (Hydnocarpus)萌发孔为三拟孔沟 ,其余均为三孔沟 ;外壁纹饰在不同属、同属不同种间表现出明显的多样化 ,基本上可分为粗网状、细网状、穿孔状、穴状4种类型。研究认为花粉形态对于该科与近缘科以及属下的划分具有一定的意义     

Pollen morphology in the family Asphodelaceae (Asphodeleae,Kniphofieae)

Pollen of 72 species from 7 genera of the Asphodelaceae was studied by means of LM and SEM in order to investigate their taxonomic relationships. The pollen of all the genera investigated is heteropolar, monosulcate, non-operculate and differs in size, form and exine ornamentation. The species of Eremurus are homogenous palynologically and studies of this genus do not support the segregation of the genera Henningia, Selonia, and Ammolirion. The pollen of Bulbinopsis mainly differs from the pollen of Bulbine species in having a perforate-areolate exine surface (B. bulbosa) but the genera are close in their other palynological features. The genera Asphodelus and Asphodeline have the largest, almost spheroidal grains with the thickest exine but differ in details of exine ornamentation. The species of Kniphofia are very close palynologically.     

天麻抗真菌蛋白对木霉菌丝的作用位点

天麻抗真菌蛋白(Gastrodia Antifungal Protein,GAFP)能强烈抑制腐生真菌菌丝的生长,在天麻限制和防止蜜环菌［Armillariella mellea (Vahl. ex Fr.)Karst.］侵染球茎的防卫机制中起重要作用。本文报告GAFP抗菌机理研究的部分内容——GAFP对木霉菌丝的作用位点。用荧光试剂异硫氰酸荧光素(Fluorescein isothiocyanate,FITC)标记GAFP,试验表明,标记后的GAFP与未标记的GAFP对木霉菌丝生长均有抑制作用。在荧光显微镜下观察GAFP在木霉菌丝上的作用位点,发现被“标记GAFP”作用后的菌丝边缘有荧光,并主要集中在木霉菌丝的顶端和菌丝横隔处,表明GAFP对木霉的作用位点在菌丝的细胞壁上。     

POLLEN MORPHOLOGY AND ULTRASTRUCTURE OF THE CABOMBACEAE: CORRELATIONS WITH POLLINATION BIOLOGY

Of all species comprising the two genera of the Cabombaceae, only Brasenia schreberi J. F. Gmel. and Cabomba caroliniana Gray have been critically investigated with regard to their pollination biology. Brasenia schreberi has been shown to be anemophilous, while C. caroliniana has an entomophilous (myophilous) pollination syndrome. In the present paper, a number of pollen and pollen-related characters, including pollen size, shape, quantity, terminal settling velocity, pollen-ovule ratios, and overall exine architecture of B. schreberi and C. caroliniana are evaluated. Pollen from both species is elliptic, monosulcate, and has a tectate-columellate sporoderm with supratectal surface ornamentation. Grains of B. schreberi are small, produced in copious amounts, and settle relatively slowly. Flowers of this species have large pollen-ovule ratios. The exine of B. schreberi pollen is scabrate, relatively thin, has a uniformly thick sexine composed of a two-zoned (homogeneous/granular) tectum and distinct columellae, and a homogeneous nexine. Pollen of C. caroliniana is relatively large, produced in small quantities, and has a rapid terminal settling velocity. Flowers exhibit small pollen-ovule ratios. Exine organization of C. caroliniana pollen is typically two times thicker than that of B. schreberi; ornamentation is striate. Nonapertural sexine regions have a thick tectum and well-defined columellae, with both sexine components traversed by a dense system of channels. The nexine is relatively thin. All of the palynological characters examined correlate well with the anemophilous and entomophilous syndromes of B. schreberi and C. caroliniana, respectively. Moreover, several other parameters of exine ultrastructure from each species exhibit positive correlations with the respective pollination mechanisms, including: tectum thickness, columellae diameter, tectum-nexine ratios, and the consistency, distribution, and total amount of pollenkitt present. Overall exine ultrastructure is also discussed from a historical perspective as well as with respect to its phylogenetic significance.     

Pollen morphology and ultrastructure of Marathrum schiedeanum (Podostemaceae)

The Podostemaceae, or river-weeds, comprise 46 genera and 270 species of dicots and are the largest family of strictly aquatic angiosperms. Despite the large size, specialized habitats, and enigmatic morphology of the family, relatively little is known about the palynology of Podostemaceae. In the current paper, pollen morphology and ultrastructure of Marathrum schiedeanum are described. Pollen grains are relatively small, spheroidal, and tricolpate to spiraperturate. The exine has a microechinate ornament, a tectate-granular sexine and a relatively thick nexine in non-apertural regions, and a semitectate sexine and thinner nexine in apertural regions. Although aperture variation occurs in the family, this is the first report of the spiral aperture type in Podostemaceae. The spiraperturate condition appears to be derived in river-weeds, as does the granular pollen wall, which represents a reduction of the typical columellae found in eudicots.