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The genus Disporum Salisb. is widely distributed in East Asia, yet phylogenetically relevant morphological traits useful for differentiating many of the small, perennial, herbaceous species remain poorly described. To address this, leaf, floral, pollen, and orbicule micromorphology of four Korean Disporum species was investigated using light and scanning electron microscopy. All Korean Disporum species examined had hypostomatic leaves, with anomocytic stomatal complexes found only on the abaxial epidermis. Guard cell length varied among species, ranging from 44.30 μm in D. viridescens to 53.49 μm in D. uniflorum. The epidermal cells of the investigated Disporum taxa had sinuate anticlinal cell walls on both adaxial and abaxial surfaces. The surface of the guard and subsidiary cells were either smooth with weak striations or had strongly wrinkled striations. The pollen grains of all Korean Disporum taxa were monads, monosulcate with granular aperture membranes, subprolate to prolate in shape with microreticulate or verrucate exine surfaces. The mean size of pollen grains ranged from 46.38 to 49.92 μm in polar length and from 34.39 to 39.58 μm in equatorial diameter across species. Sexine ornamentation was a taxonomically relevant trait for differentiating Korean Disporum taxa. Additionally, the presence of orbicules as well as the orbicular characters (e.g., size, shape, ornamentation, and association pattern) are described for the first time in species from this genus. The present investigation of leaf and floral micromorphology using light and scanning electron microscopy provides valuable information for the taxonomic differentiation and identification of Disporum species in Korea. RESEARCH HIGHLIGHTS: A detailed micromorphological description of leaf, floral characters (tepal, stigma, style), pollen and orbicule is provided for Korean Disporum species using scanning electron microscopy (SEM) and light microscopy (LM). The presence of orbicules and their taxonomic implications in Korean Disporum species are described for the first time. Phylogenetically informative pollen and orbicule micromorphological characters are described, improving understanding the systematic relationships of Korean species in the genus Disproum.

The palinomorphological features of six species of the genus Hypericum (H. аlpigenum, H. elegans, H. hirsutum, H. maculatum, H. montanum, H. perforatum) of the flora of Ukraine have been investigated. All species studied are valuable medicinal plants. However, only two species of raw material are officially permitted: H. perforatum and H. maculatum. Raw materials of other species can also be harvested from natural habitats, as they are wide spread in some regions of Ukraine and morphologically similar to pharmacopoeial species, but their admixture to the raw materials reduces its quality. The aim of research was to make a comparative morphological analysis of pollen grains six species of genus Hypericum of Ukrainian flora for determine the common and distinctive features that will identify the species of raw materials. We used a scanning electron microscope to investigate the pollen grains ultrascultures (CEM, JSM 6060 LA). The studies were performed according to the standard method. As a result of palynomorphological studies of six species of the genus Hypericum of the flora of Ukraine established, that the pollen grains of the species studied are small-sized, 3-colporate, ellipsoidal or spheroidal, outline in polar view ‒ trilobate, rounded-triangular, in equatorial elliptical. In all studied species the colpi are long, mostly with distinct margins, pointed ends and a granular membrane. The pores are undistinct. Sculpture exine in the investigated species of the genus Hypericum of the flora of Ukraine are microreticulate (H. perforatum, H. alpigenum) and reticulate (all other species studied). Morphometric features of pollen grains of the studied species: the length of the polar axis, equatorial diameter, colpus width, mesocolpium width, the diameter of the apocolpium, the ratio of the length of the polar axis to the equatorial diameter, the ratio of the mesocolpium widths and aperture widths can be used as additional diagnostic features in identification species of the genus Hypericum of Ukrainian flora.

We aimed to unravel the underlying mechanisms of pollen wall development in Hydrangea bretschneiderii. For this, we tested our hypothesis that distinct physical processes, phase separation and micellar self-assembly, underpinned exine development by taking the substances, determined by the genome, through several phase transitions. We traced each developmental stage with TEM; then, we obtained in vitro simulations corresponding to those stages. The main steps of exine ontogeny observed in the microspore periplasmic space were initiated with phase separation, resulting in the conversion of homogeneous contents to heterogeneous two-layered state of the material. After each step of phase, separation self-assembly picked up the initiative and took the substances through the sequence of micellar mesophases which were the base for all the exine structures. These mesophases are as follows: spherical micelles, transforming first into columns, and then to cylindrical micelles which turn to columellae after initial sporopollenin accumulation. The tectum appeared along the interface of the phase separated material. After the tetrad disintegration and the next phase separation, laminate mesophase appeared being the base for the endexine lamellae. Then, a new step of phase separation at aperture sites brought the appearance of a granular endexine layer; the latter became intermixed finally with lamellae. This gives, together with experimental simulation, strong evidence that the genome “shifts a part of work” on exine formation onto physical processes, and the latter are an inherent mechanism of evolution.

Common vetch (Vicia sativa) is an important forage and green manure crop that is widely cultivated around the world. However, the large number of subspecies and accessions of common vetch has made taxonomic research on this species difficult. Pollen morphology data can provide important evidence in the study of plant phylogeny. Therefore, in this research, light microscopy and scanning electron microscopy were used to observe seven morphological traits of pollens from 22 common vetch accessions, and residual maximum likelihood and pattern analysis was conducted. The results showed that the pollen grains of the 22 accessions were all monad pollen and the polar view revealed three-lobed circular and triangular shapes, while the equatorial view mainly revealed an oblate shape; only one accession showed an oblate spherical shape. All accessions were 3-zonocolporate and the colpus length extended close to the poles. The polar axis length was (19.39 ± 0.97)–(42.12 ± 0.76) μm and the equatorial axis length was (35.97 ± 1.27)–(45.25 ± 0.81) μm. We found that qualitative traits of pollen shape, aperture polar view and ornamentation were highly stable. Among them, polar axis length, equatorial axis length and colpus length and width had significant differences among the accessions. The ratios of the equatorial and polar axes had significant differences among the subspecies. This trait information could be used for the classification and identification of common vetch accessions and subspecies.

This study analyzed pollen morphology and characteristics of 20 Sambucus nigra L. genotypes from populations of various ecotypes and geographical localities from the territory of Slovakia. We used principal component analysis to explore variability in pollen grain size (polar and equatorial diameter), shape, aperture type, and exine ornamentation by scanning electron microscopy. The combination of these morphological characteristics and ultrastructure allows us to determine the differences or similarities between the same and various species and genotypes, which may be a useful tool for systematics with significant diagnostic value. The findings confirmed small differences among the genotypes in measured traits with polar and equatorial diameters in the range from 22.30 to 26.64 μm and from 12.81 to 14.45 μm, respectively. Shape index (P/E ratio) depending on elongation or roundness of pollen grains varied from 1.66 to 2.02. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) of morphological data helped to compare evaluated morphometric parameters and identified three closely related groups. It was noted that the diversity of surface sculpturing of pollen grains in combination with their shape and size enables us to use a complex of fine morphologic signs for S. nigra pollen identification. Pollen data combined with other morphological evidence (e.g., floral characters) have more recently become an important indicator of which genotypes may be the best representatives of species.

Background.Learning about morphological and biological features of pollen is very important to make correct estimations of plant productivity and breeding efficiency.Materials and methods. The viability of black currant pollen was analyzed in 2019 at the Laboratory for Long-Term Storage of Plant Genetic Resources, N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). Eleven black currant cultivars of various ecogeographic and genetic origin maintained at Pushkin and Pavlovsk Laboratories of VIR served as the material for the research. Pollen viability was tested on an artificial medium with 10% sucrose and 0.8% agar. Morphological studies were carried out using light and confocal laser scanning microscopy at the Palynology Laboratory and the Core Centrum of Cell and Molecular Technologies in Plant Science housed by the Komarov Botanical Institute (BIN).Results and conclusion. The prevailing adverse weather conditions in 2019 produced a negative impact on the process of male generative structure formation. The level of pollen viability, depending on the cultivar, ranged from 17.98 to 58.60%. After exposure to liquid nitrogen (–196°C) for 6 months, the number of germinated pollen grains increased 1.1 to 3.2 times in all the studied cultivars, except one (‘Pozdnyaya poslevoennaya’, k-7652). A palynomorphological study revealed that reduced pollen viability in some cultivars (‘Krasnoyarskaya 1018’, k-7607; ‘Tsema’, k-25900; ‘Pozdnyaya poslevoennaya’, k-7652) was associated with morphological deviations in the sporoderm structure (small pollen grains, exine thickening and formation of verrucate mesoporium surfaces). A low positive correlation was observed between the level of pollen viability and the diameters of the pore (r = 0.43) and pollen grain (r = 0.27). An insignificant negative correlation was apparent between the level of viability and the exine thickness (r = –0.33).

subgenus Passiflora possesses about 236 species divided into six supersections, among which Stipulata with Granadillastrum is one of its sections. The objective of the present study was to analyse ...

Pollen morphology of 28 species and 5 varieties representing 8 genera of subfamily Polygonoidae (Polygonaceae), collected from various altitudinal ranges of Darjeeling Himalaya, sub-Himalayan Terai, Duars, Gangetic plains, Sundarbans and Western plateau of West Bengal and NE India, were examined critically under light (LM) and scanning electron microscope (SEM) to explore their distinctive features. Anthers were processed through acetolysis method and obtained grains were properly studied, measured and photographed. The shape, size, aperture type and exine ornamentation of pollen grains served as a reliable features in current study as taxonomic tool for the authentic identification at species and varietal level. The studied characters under LM and SEM were further statistically analyzed through ANOVA, PCA, Pearson Correlation Matrix to understand the interrelationship among the taxa and pollen grains were recorded monad, isopolar and radiosymmetric type. Pantoporate, tricolpate, tricolporate aperture type and exine ornamentation appears to be valuable and unique characters were found useful tool for the delimitation and differentiation of closely related taxa.

The family Cactaceae is the diversified group of angiosperm plants whose pollen statistics has been used for taxonomic identification. In this article, we present the pollen morphology of eight species belong to seven taxonomically complex genera of Cactaceae including Astrophytum, Cylindropuntia, Echinocereus, Echinopsis, Mammillaria, Opuntia, and Thelocactus using light and scanning electron microscopy. The pollen grains were acetolyzed, measured, described, and electron photomicrographs were taken. Cactaceae can be characterized by presenting different palynomorphological features including pollen type, sculpturing, polar and equatorial diameter, aperture orientation, exine thickness, P/E ratio, and echini features. Four types of pollen shapes, that is, prolate spheroidal (three species), subprolate (two species), prolate (two species), and oblate spheroidal in Echinocereus reichenbachii were observed. The polar and equatorial diameter observed maximum in O. ficus indica 116.95 and 112.27 μm while minimum in M. compressa 38.42 and 21.05 μm. Pollen of two types, tricolpate in members of subfamily Cactioideae and pantoporate in the Opuntioideae were examined. The fertility percentage has been observed maximum in Opuntia macrocentra (83.84%) and minimum in Opuntia ficus-indica (57.89%). Exine sculpturing showing great variations such as granulate, reticulate, granulate perforate and micro-echinate foveolate ornamentation was examined only in Echinopsis eyriesii. A key to species, based on pollen micromorphological attributes, has been constructed for correct identification of complex cactus species.

This study aims to expand knowledge of the pollen morphology of Passifloraceae and contribute to the taxonomic delimitation of the group by morphologically characterizing pollen grains of species that occur in the Brazilian state of Bahia. Thirty-six species occur in the state, one of the genus Mitostemma (M. glaziovii) and 35 of the genus Passiflora. Pollen samples were acetolysed, measured, and described using light and scanning electron microscopy. The results group the studied species into four pollen types based mainly on aperture type and number, opercular variation, and the presence/absence of ornamentation elements inside the lumina of the reticulum: Pollen type I - species belonging to the subgenera Astrophea and Deidamioides; pollen type II - subgenus Decaloba; pollen type III - subgenus Passiflora; and pollen type IV - M. glaziovii, with pollen characteristics that separate it from the other species analyzed. The results reinforce the recognition of three subgenera of Passiflora. Morphopalynologically the species have very similar pollen types except for those of the subgenus Deidamioides, which are quite diverse and thus included in another pollen type. The results reveal the importance of pollen grains for the taxonomic study of Passifloraceae.

Made available in DSpace on 2022-04-29T08:30:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 We analyzed the pollen morphology of 13 Brazilian native species of Malvaceae s.l. from forest fragments of Cerrado belonging to nine genera [Bastardiopsis (K. Schum.) Hassl., Byttneria Loefl., Ceiba Mill., Eriotheca Schott & Endl., Guazuma Adans., Helicteres L., Heliocarpus L., Luehea Willd. and Pseudobombax Dugand] in search for characters that can expand the knowledge on the pollen morphology of species of the family that occur in areas of fragments. The pollen grains were acetolyzed, measured, described and photographed under light microscopy and scanning electron microscopy. The species studied were grouped into two pollen types based mainly on the type of aperture [simple aperture (3-porate or 4-colpate) and compound aperture (3-pororate or 3-colporate)], and the quantitative data were analyzed using descriptive and multivariate statistics. Details of apertures (planaperturate, angulaperturate, type of endoaperture, costa, aspis and atrium) and exine ornamentation (verrucate, microreticulate, microreticulate-echinate, reticulate and bireticulate) contributed as secondary data to the segregation of species in an artificial pollen key. The metric characters examined by multivariate analysis allow the distinction of groups of species, based on the length of the apertures and the diameters of the pollen grains. Our results allow the identification among genera and species of Malvaceae s.l. in Brazilian forest fragments. Programa de Pós-Graduação em Biologia Comparada Faculdade de Filosofia Ciências e Letras Universidade de São Paulo (USP), SP Programa de Pós-Graduação em Biodiversidade Vegetal Departamento de Educação Universidade do Estado da Bahia (UEB) Campus VII, BA Departamento de Biologia Aplicada à Agropecuária Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), SP Departamento de Biologia Aplicada à Agropecuária Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), SP

A morfologia polínica de nove espécies de Chrysophyllum (Sapotaceae) foi descrita sob a microscopia de luz. Os grãos de pólen foram coletados de amostras herborizadas, acetolisados, montados entre lâminas e lamínulas, analisados quantitativa e qualitativamente, descritos e fotomicrografados. As espécies estudadas de Chrysophyllum caracterizaram-se por apresentarem grãos de pólen mônades, tamanho variando de pequenos à médios, isopolares, com forma subprolata a prolata, amb subtriangular, subcircular e subquadrangular, 3-4-colporados, exina psilada, microrreticulada, levemente estriada. As espécies de Chrysophyllum estudadas apresentaram grãos de pólen com pequenas variações morfológicas, especialmente quanto ao número apertural e à ornamentação da exina. Assim, por se tratar do primeiro estudo na Bahia, abordando a morfologia polínica do gênero, poderá subsidiar futuros trabalhos, tanto local como regional, nas diversas áreas da Palinologia.

The mycoheterotrophic genus Thismia shows a great number of structural and ecological traits which are rare or unique for angiosperms. Pollen morphology of this genus is still poorly known. Pollen of Thismia was reported to be porate with one to several pores. Position of the pores is unknown, and therefore, the pollen type has not been established to date. Information on sporoderm structure in the genus is scarce, as high-quality images of pollen grains are available for several species only. In our comprehensive investigation of pollen morphology of Thismia, we involved nine Asian species of the genus and employed an integrative approach, which included data from light microscopy, scanning electron microscopy and transmission electron microscopy. All studied species were shown to possess monoporate pollen of asymmetric-elliptic planoconvex shape. Using TEM investigation of immature anthers, we demonstrated that pollen grains are organized in tetragonal tetrads, and the pore occupies an equatorial position. We argue that Asian species of Thismia along with Burmannia from the same order Dioscoreales are the only known lineages of seed plants with a single equatorial aperture. The sporoderm surface is psilate or perforate with perforations of various size and density in the studied species. We discuss the interspecific variation of sporoderm morphology in the light of the phylogenetic relationships between Asian species of Thismia. We demonstrate that the pollen morphology of Thismia fails to conform to the idea of entomophily, which is believed to prevail in this genus. Finally, we describe an unexpected striking difference in sporoderm structure between the specimens belonging to T. javanica species group.

Pollen, the microgametophyte of seed plants, has an important role in plant reproduction and, therefore, evolution. Pollen is variable in, for example, size, shape, aperture number; these features are particularly diverse in some plant taxa and can be diagnostic. In one family, Boraginaceae, the range of pollen diversity suggests the potential utility of this family as a model for integrative studies of pollen development, evolution and molecular biology. In the present study, a comprehensive survey of the diversity and evolution of pollen from 538 species belonging to 72 genera was made using data from the literature and additional scanning electron microscopy examination. Shifts in diversification rates and the evolution of various quantitative characters were detected, and the results revealed remarkable differences in size, shape and number of apertures. The pollen of one subfamily, Boraginoideae, is larger than that in Cynoglossoideae. The diversity of pollen shapes and aperture numbers in one tribe, Lithospermeae, is greater than that in the other tribes. Ancestral pollen for the family was resolved as small, prolate grains that bear three apertures and are iso-aperturate. Of all the tribes, the greatest number of changes in pollen size and aperture number were observed in Lithospermeae and Boragineae, and the number of apertures was found to be stable throughout all tribes of Cynoglossoideae. In addition, the present study showed that diversification of Boraginaceae cannot be assigned to a single factor, such as pollen size, and the increased rate of diversification for species-rich groups (e.g. Cynoglossum) is not correlated with pollen size or shape evolution. The palynological data and patterns of character evolution presented in the study provide better resolution of the roles of geographical and ecological factors in the diversity and evolution of pollen grains of Boraginaceae, and provide suggestions for future palynological research across the family.

Allergenic pollens are found in gardens, fields and green spaces around cities. In Kermanshah, located in the west of Iran, seven allergen pollen samples were collected directly from nature and studied according to the Erdtman acetolysis method by using Light Microscope (LM) and Scanning Electron Microscope (SEM). In this study, atmospheric pollens were also examined by the Durham method. The results showed that the pollen grains were small, medium, and large in terms of size, and Triporate, Pantoporate, Colpate and Tricolporate in terms of aperture. In addition, they were Striate, Perforate, Macroechinate, Microechinate, and Psilate with regard to exine ornamentation; however, the echinate type was more common. In general, Prolate to a spherical shape, medium-sized, perforate, and echinate pollen characteristics are popular in the important allergenic plants. Therefore, due to the human's manipulations in nature and also the extensive size of gardens and fields, there are many types of weeds in Kermanshah Province which are significant in terms of being allergenic.

The late Cretaceous Corsinipollenites from central India and its nearest living fossil pollen Ludwigia from Pleistocene Karewa sediments in Kashmir shows morphometrical affinities with pollen of seven extant Ludwigia species (L. octovalvis (Jacq) P.H. Raven, L. octovalvis subsp. sessiliflora (M.Micheli) Raven, L. adscendens (L.) H. Hara, L. perennis (L.), L. hyssopifolia (G.Don) Exell, L. peruviana (L.) H. Hara and L. decurrens Walt.) commonly growing in swampy ecosystems of India. The Field Emission Scanning Electron Microscope (FESEM) and Light Microscope (LM) study draws plausible lineage of extant Ludwigia species with that of fossil specimens recovered at two different time frames based on similarities in pollen morphometry. The pollen aperture and its character along with the sexine pattern were main identifiable features to distinguish different species of extant/fossil Ludwigia pollen. The aspidote aperture varies from brevi-colporate to slit-like colpi (colporate). The sexine is stenopalynous type characterized by rugulate to reti-rugulate pattern. The multivariate principal component analysis (PCA) was applied on the numerical data obtained from pollen morphometry of living and fossil Ludwigia spp. The Pleistocene Ludwigia morphotype with slit-like colpi shows close proximity to L. octovalvis, L. octovalvis subsp. sessiliflora and L. adscendens. However, Late Cretaceous, Corsinipollenitis characterized by brevicolpi is closer to L. perennis and L. hyssopifolia with respect to primary pollen characters and inferred as primitive species having lineage to the “Old World” (paleotropical) species. A short pollen key of Ludwigia spp., is presented here to enable the identification of living/fossil pollen.

Pollen grains of ten species of Kickxia (Plantaginaceae, previously assigned to Scrophulariaceae), two species of Scrophularia (Scrophulariaceae) and one species of genus Plantago (Plantaginaceae) in Saudi Arabia were studied using both light and scanning electron microscopy. The most obvious findings in Plantago major are: Pantoporate pollen class (5–9), pollen shape class prolate—spheroidal, a polar, pollen shape—circular, circumaperture, apocolpium—absent, aperture type—annular and pollen wall sculpture—verrucate. This result showed that Plantago major was separated by their pollen morphological characteristics away from the other two studied genera. This result supports some taxonomic views of some scientists in maintaining Plantago species in a separate monogeneric family (Plantaginaceae) and keeping Kickxia and Scrophularia within the Scrophulariaceae family.

Dispersed trisulcate pollen grains of Pretricolpipollenites bharadwajii from the ?latest Permian of Jordan were studied with light, scanning, and transmission electron microscopy. The three sulci are located on the disal side. The median sulcus is usually longer, wider than the other two sulci, and has rounded aperture ends. The exine sculpturing and aperture membrane are scabrate. The ectexine includes a thick tectum, granular infratectum, and thin foot layer. The endexine is lamellate. A comparison with the closest similar genus Eucommiidites suggests overlapping characters; though the position of the three sulci on the distal side in Pretricolpipollenites bharadwajii and sulci on different sides in Eucommiidites indicates a possible distinguishing feature. Studies of exine ultrastructure of the other two Pretricolpipollenites species are needed to support or discard the distinction of Pretricolpipollenites and Eucommiidites.

Due to overlapping and diverse morphological characters, Berberis is among the most taxonomically complex genera. Palynology is one of the taxonomic tools for delimitation and identification of complex species. In this study, pollens of 10 Berberis species were analyzed through light and scanning electron microscopy. Qualitative as well as quantitative features (pollen shape, size, presence or absence of colpi, colpi length and width, exine thickness, ornamentation, pollen class, aperture, and polar-equatorial ratio) were measured. Five species were observed to have colpate (pantocolpate) with elongated ends, radially symmetrical, isopolar, monads, and psilate-regulate pollens. In polar view, six pollen were spheroidal, two were ovoid, one spherical, and one oblate. Similarly, variation in pollen length was prominent and the largest pollen on polar view was recorded for B. psodoumbellata 60-65 μm (62.4 ± 0.9), while the smallest one was observed for B. lycium 29-35 μm (32.2 ± 1). The observed variation in both quantitative and qualitative features were important in taxonomic identification. This shows that palynological characters are helpful in identification of Berberis genus at the species level.

Made available in DSpace on 2019-10-04T12:39:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-04 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The genera Eriosema and Rhynchosia, which comprise approximately 150 and 230 species, respectively, belong to the tribe Phaseoleae and to the subtribe Cajaninae. The pollen morphology of 49 species of Eriosema and 13 of Rhynchosia were studied using scanning electron microscopy to identify diagnostic characteristics that could aid in the taxonomic circumscription of those genera. The pollen grains analysed were obtained from specimens deposited in the BOTU, CEPEC, IPA, HRB, HUEFS, OUPR, P, S, UFC, and UFRJ herbaria. The species studied demonstrated that the pollen grains dispersed in monads, are isopolar or heteropolar, triporate or tricolporate, angulaperturate; with the endo-aperture membrane generally psilate and the exine largely reticulate heterobrocate, except for R. claussenii which is microreticulate. We discuss these diverse characteristics, including the ornamentation of the endo-aperture membrane and the margins of the apertures and reticula, to obtain information that possibly could be used to differentiate between the two genera. Although this proved not to be possible using pollen, because many characters overlap between the two genera, nevertheless some species display unique, taxonomically useful, characters, such as R. platyphylla which has an apocolpium in the shape of a 'Y', E. bauchiense with a verrucate exine ornamentation, and E. benthamianum with fossulate lumina. Additionally, two pollen types were identified in Eriosema, one group of species with 3-porate pollen grains and the other composed of species with 3-colporate grains. Univ Estado Bahia, Programa Posgrad Biodiversidade Vegetal PPGBVeg, Dept Educ, Campus 8, Paulo Afonso, Brazil Univ Estado Bahia, Dept Ciencias Humanas, Campus 6, Caetite, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Bot, Programa Posgrad Ciencias Biol Bot, Botucatu, SP, Brazil Royal Bot Gardens, Comparat Plant & Fungal Biol Dept, London, England Univ Estadual Paulista, Inst Biociencias, Dept Bot, Programa Posgrad Ciencias Biol Bot, Botucatu, SP, Brazil

The leaf stomata of some evergreen plants have cuticular rings. According to dynamic modeling, being the ribs of rigidity these rings are able to influence the stomatal mechanics. The cuticular folds are typical of the leaf surface of many flowering plant species. They are often present on the stomatal complex cells. The functions of such folds are still underinvestigated. This study aims to elucidate the role of the stomatal rings in guard cell mechanics. Light, scanning, and transmission electron microscopy were used to study the stomata of the leaf epidermis in Viburnum suspensum (Caprifoliaceae), Lauro-cerasus officinalis (Rosaceae), Exbucklandia populnea (Hamamelidaceae), and Acokanthera oblongifolia (Apocynaceae), which have stomatal rings. The rings are formed by cuticular folds and can be located either immediately on guard cell walls around the outer ledges (marginal stomatal rings), or on the outer ledges themselves (rings of ledges). To elucidate the role of the rings, we have applied dynamic modeling using the finite element method. The data on the shape of the guard cells, uneven thickness of their walls, localization and the relative sizes of stomatal ledges and rings were exactly reproduced during model stomata construction. The turgor pressure was simulated by creating the load distributed on the inner surface of the guard cells. The guard cells of all studied species are located on the subsidiary or neighboring cells. The modeling has shown that the presence of the marginal rings leads to sinking of the opening stomatal pores into epidermis. The depth of the sinking depends on mechanical characteristics of marginal rings. The rings of ledges rib the outer ledges and prevent the outer ledges aperture widening when the stoma is opening.

Primula merrilliana is a distylous, rare, vulnerable herb and of high value in horticulture. Previous studies indicated that the genetic differentiation among populations of this species was remarkably greater than that of its closely related species, suggesting that it may not be a single homogeneous species. In order to further explore the natural variation and identity of the species, pollen morphology and ITS DNA sequences of 18 populations covering its whole distribution were investigated. According to the pollen shape and aperture type, P. merilliana has two different pollen types; six populations from the northwest corner of the distribution area have stephanocolpate and suboblate pollen grains, while the remaining 12 populations possess pantoporate and spherical pollen grains. The mean genetic distance among populations with the same pollen type (mean 0.009) was significantly lower than that of populations with different pollen types (mean 0.023). Pollen morphological characteristics of P. merrilliana have taxonomic value for species identification, suggesting that P. merrilliana is a species complex that comprises two different species. Pollen size variations support the hypothesis that Fenghuangshan (FHS) and Dongshan (DSC) populations, having both sexual organs at the mouth of corolla tube, are long-homostyled populations (not a phenotype with stamen modification of a long-styled morph), while the Qidu (QD) population, having both sexual organs at the middle of the corolla tube, is a short-homostyled population (i.e. not a stamen modification of a short-styled morph).

A fragmentary pollen organ with four to six microsporangia is discovered from the Middle Jurassic of the Irkutsk coal basin, Siberia. The in situ pollen grains are boat-shaped, monosulcate, and with a nearly psilate surface. The non-aperture ectexine is composed of a thick solid tectum, a thin infratectum, and a thin foot layer. The infratectum includes one row of small rare alveolae. The supposedly poorly preserved endexine is thin and grainy. The ectexine reduces greatly in the aperture area, where only homogeneous ectexinal patches are present over the endexine. The pollen grains under study resemble in their exine ultrastructure pollen grains of the modern Ginkgo biloba and pollen grains from dispersed seeds of a presumably ginkgoalean affinity from the Middle Jurassic of Uzbekistan. This suggests that the ginkgoalean exine ultrastructure of the modern type existed as early as the Middle Jurassic. The exine ultrastructure under study is also similar, though to lesser degree, to that of dispersed pollen grains of a presumed ginkgoalean affinity from the Cretaceous of the Russian Far East. The diversity of such a long-living group as ginkgoaleans is apparently reflected in the diversity of their exine ultrastructure. To the present knowledge, ginkgoalean pollen grains can be differentiated from similar boat-shaped monosulcate pollens by the following co-occurring characters: a thick homogeneous tectum, a thin infratectum with one row of structural elements, a thin foot layer, and an ectexine that is reduced in the aperture region to patches.

Sudarmono. 2018. Short Communication: Pollen diversity in the Bogor Botanic Gardens, Indonesia. Biodiversitas 20: 931-936. Pollen morphology influenced the process of plants evolution. Bogor Botanic Gardens has many living collections in terms of pollen diversity. The purpose of this study was observed at the diversity of pollen morphology at the Bogor Botanic Gardens and its implications for the pollen conservation of plants in the collection. The method used is cleaning the pollen using Glacial Acetic Acid (AAG), then examined using a light microscope in the tissue culture laboratory of Bogor Botanic Gardens. There were 35 specimens that were analyzed and the results were randomly shaped pollen from radial symmetry or bilateral symmetry to its combination with monocolpate, tricolpate, pericolpate and stephanocolpate. While aperture types were the monoporate type with 5 specimens, monocolpate 10 specimens, tricolpate 11 specimens, stephanocolpate 4 specimens, periporate 4 specimens, and syncolpate 1 specimen. Three specimens families Caesalpiniaceae (order Fabales) has the shape of pollen vary, i.e radial symmetry monocolpate and radial symmetry tricolpate. Similarly, two specimens of the family Araliaceae (Apiales) different shapes, namely radial symmetry and bilateral symmetry tricolpate. In Asteraceae and Asclepiadaceae has the same shape, the radial symmetry tricolpate. Overall of 35 specimens then there are 22 specimens of radial symmetry and 13 specimens of bilateral symmetry. For the same family have the same ornamentation, for example in the Lamiaceae, Malvaceae, and Rutaceae. But the uniqueness occurs in the family of Arecaceae or palm family that show the diversity in the shape and size of pollen in each genus. Pollen morphology analysis through a combination of morphological data, palynology, and molecular samples more would be better. Pollen bank as pollen in the living collections of Bogor Botanic Gardens is needed to germplasm conservation of endangered plants in Indonesia.

Pollen pattern plays an important role in discriminate and definite infraspecific as well as interspecific diversity for species recognition. In this study, we analyzed pollen morphology of the 86 accessions under nine currently recognized taxa of Acmella to estimate our current understanding of the phylogeny of this genus. Species relationship can be evaluated on the basis of pollen characteristics. The study shows the significance of palynological characteristics such as aperture type, spine length and nature, stature of basal cushion and sculpturing pattern in the delimitation of taxa in the interspecific levels. Pollen grains of these species are isopolar, zonocolporate pollen and are radially symmetric. Shape is more or less circular in polar view, with the colpi slightly intruding, from circular to slightly elliptical in equatorial view. But the number of colpus and ora varies. Acmella calva, A. uliginosa and A. uliginosa Var. pentamera have 3-zonocolporate pollen, A. ciliata, A. ghoshinis, A. radicans and A. tetralobata have 2, 3, 4 zonocolporate pollen and A. vazhachalensis and A. paniculata have 2, 3, 4, 5 zonocolporate pollen. Pollen shape varied from oblate spheroidal to prolate spheroidal. Exine is thick, 2.1–5.2 µm normally. Ornamentation is spinate; 1.16–5.46 µm long, spine apex shape varies in each species. Scanning electron microscopic studies showed differences in the spine length, spine structure and attachment. We used statistical analysis to explore variations in pollen grain size and shape among Acmella species, and to compare systematic groupings of Acmella based on pollen characters.

In this study we focus on the pollen morphology of Physaria kingii subsp. kaibabensis and two congeners, Physaria arizonica and P. kingii subsp. latifolia, found on the Kaibab Plateau, Arizona, to differentiate further among these species. We collected plant material from 2 sites/species, with 10 plants/site used to image 10 pollen grains/plant. We described pollen grains (i.e., polar axis [P], equatorial diameter [E], P/E ratio, shape, exine structure, and aperture number) using scanning electron microscopy. All species imaged had pollen grains with reticulate surfaces and were pentacolpate. We found significant differences among species for equatorial diameter and P/E ratio, but not for polar axis. This study provides additional information that can be incorporated in species descriptions.

SUMMARY Interaction between the pollen grain, pollen tube and the stigma surface has been studied in five species regarded as possessing dry stigma surfaces; Brassica oleracea L., Arabidopsis thaliana (L.), Heynh, Papaver rhoeas L., Cosmos bipinnatus Cav. and Helianthus annuus L. In B. oleracea and A. thaliana, stigmatic response to pollination includes events in the papillar cytoplasm and changes to the stigmatic surface beneath the grain. In particular a specialized outer element of the cell wall expands prior to pollen tube penetration. The pollen tube, which enters through a ‘foot’ of pollen coating, grows in a space generated between an inner and the outer element of the wall and extends to the base of the papilla where it enters the middle lamellae of the subjacent cell layer. However, in A. thaliana tubes frequently were seen to penetrate all components of the stigmatic cell wall, an event only previously recorded in immature stigmas of B. oleracea. In self pollinations of self-incompatible B. oleracea involving strong S (incompatibility) alleles no changes take place in the papillar cell wall. In P. rhoeas the stigmatic surface responds to self and cross pollination by the secretion of electron-lucent material beneath the cuticle, causing it to become detached from the outer surface of the stigmatic cell wall. The pollen tubes then penetrate the cuticle and grow towards the base of the papilla in the space thus generated. The tubes continue to grow intercellularly in the transmitting tissue which lies horizontally in rays beneath the papillae. In members of the Compositae, C. bipinnatus and H. annuus, both stigma and pollen respond to pollination by producing copious quantities of an electron-opaque matrix, which frequently causes individual papillae to adhere together. Pollen tubes, which are formed following both compatible and incompatible intraspecific pollinations, grow into this matrix and toward the base of the papillae. There, in common with the other plants studied, they grow intercellularly and enter the transmitting tissue of the style. These findings are discussed in the light of current views of the mechanisms operating during angiosperm pollination and of the significance of the stigmatic response to the functioning of self-incompatibility mechanisms.

Proxapertites have become one of the most significant indicators of ancient rock in Indonesia. Walat Formation is one of the oldest rocks exposed in Sukabumi, West Java, Indonesia. These Proxapertites have not been described in detail about their characteristics in previous studies, especially on Walat Formation. Therefore, knowing the characteristics of Proxapertites becomes interesting, especially in Walat Formation, which can be a reference for the characteristics of the late Eocene Proxapertites (37.8 - 33.9 million) in Indonesia. Acetolysis method was carried out for the preparation of pollen and spores; description and determination were carried out to see the characteristics of Proxapertites that present in Walat Formation. Result, there are three types of Proxapertites. Proxapertites operculatus have sizes 23 – 86 µ with average 40.5 (P) and 51.1 (E) µ, index PE 0,43 - 1, Peroblate – Subspheroidal – Oblate Spheroidal, Fine-Reticulate ornamentation, and Asymmetric Monosulcate aperture. Proxapertites cursus have sizes 23 – 86 µ with average 39.8 (P) and 49.8 (E) µ, index PE 0.51 - 1, Oblate – Subspheroidal – Oblate Spheroidal, Reticulate ornamentation, and Asymmetric Monosulcate aperture. Whereas Proxapertites psilatus have sizes 29 – 75 µ with average 42.3 (P) and 52.5 (E) µ, index PE 0.58 - 1, Oblate – Subspheroidal – Oblate Spheroidal, Psilate ornamentation, and Asymmetric Monosulcate aperture. These three Proxapertites can be distinguished by their type of ornamentation. Meanwhile, other aspects have similar characteristics and are affected by the appearance of individual pollen on the slide during preparation.

Pollen morphology of 19 taxa in Persicaria section Cephalophilon and four related taxa in the genus Koenigia was examined. Pollen grains shed as a monad were oblate to subprolate in shape (P/E = 0.50–1.20), small to large in size (13.44–51.16 μm), and tricolpate, octocolpate, or pantoporate. Three types of exine ornamentation were identified: (I) reticulate (P. sect. Cephalophilon), (II) reticulate with microechinae (Koenigia delicatula), and (III) microechinate (studied taxa of Koenigia except K. delicatula). The quantitative pollen characteristics analyzed using principal component analysis showed diagnostic importance among the taxa. The comprehensive consideration of pollen characteristics (aperture type, pollen size, and detailed exine ornamentation) is systematically informative, particularly at the series level of P. sect. Cephalophilon. Furthermore, the results also support the separation of some taxa of uncertain taxonomic affinities between Koenigia and P. sect. Cephalophilon. Orbicules were absent in all taxa of P. sect. Cephalophilon but were consistently found in Koenigia. The examined orbicules were spherical with a psilate surface, and the studied orbicule characteristics provided additional evidence to clarify the taxonomic position of some taxa of Koenigia. The orbicule and pollen morphology, especially aperture types, has proven to be a useful diagnostic characteristic in P. sect. Cephalophilon and related taxa, and their systematic importance is further discussed in this study.

Made available in DSpace on 2022-04-29T08:38:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Boraginaceae s.l., the single family of Boraginales, are extremely diverse in terms of morphology, and their species are well distributed in South America especially in Brazilian ecosystems. The pollen morphology of 11 Brazilian native species and four genera (Cordia L., Varronia P. Browne, Heliotropium L. and Myriopus Small) of Boraginaceae s.l. was investigated to expand the morphological knowledge of the species, contributing new data on the palynology, taxonomy, and conservation of the family. The pollen grains were acetolyzed, measured, photographed using light microscopy (LM) and scanning electron microscopy (SEM), and described qualitatively. The analyzed species present differences in size, shape, type and number of apertures (3-porate, 3-colpate, 3-colporate and heterocolpate) and exine ornamentation (psilate, echinate, microechinate-verrucate, reticulate and rugulate) of the pollen grains, allowing the species studied to be distinguished. Multivariate analysis of measurements confirms the qualitative description and pollen diversity in Cordiaceae species. Smaller diameter values and similarities in aperture and exine ornamentation characterize the Heliotropiaceae species. Our data reinforce the taxonomic importance of pollen morphology and of Boraginaceae s.l. as eurypalynous. Faculdade de Filosofia Ciências e Letras Programa de Pós-Graduação em Biologia Comparada Universidade de São Paulo (USP) Faculdade de Ciências Agrárias e Veterinárias Departamento de Biologia Aplicada à Agropecuária Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias Departamento de Biologia Aplicada à Agropecuária Universidade Estadual Paulista (UNESP)

The present study was carried out on scanning electron microscopic-based palynological characterization of selected 20 Euphorbiaceae taxa. In this study, important pollen qualitative and quantitative features of selected Euphorbiaceae species such as polar diameter, equatorial diameter, P/E ratio, sculpturing of pollen, exine thickness, intine thickness, presence or absence of colpi and length of colpi, and pollen fertility were examined. Remarkable variations in these pollen characters had been observed among these species. In both polar and equatorial views, Riccinus communis L. exhibited the highest pollen size (polar = 264.1 μm, Equatorial = 270 μm), while Acalypha wilkesiana Mull Arg. showed lowest pollen size (Polar = 17 μm, Equatorial = 18.5 μm). Most of the pollen varied from oblate to spheroidal in shape. With regard to the P/E ratio, Sapium sebiferum L. Roxb showed the highest ratio while Bischofia javanica Blume showed minimum, that is, 1.18 and 0.85, respectively. Intine and exine thickness also varied. Most of the pollen grains were monade. Tricolporate, tricolpate, monocolpate, pentaporate, and polyporate pollen aperture types have been observed. Most of the plants showed regular, reticulate, and echinate pollen sculpturing. Pollen fertility also varied from species to species but most of the plant showed pollen fertility between 70 and 80%. Through this work, it has been concluded that quantitative and qualitative pollen features are helpful at the specific level as well as the generic level and can provide a fruitful taxonomic solution.

The genus Rubus is one of the largest taxonomically diverse and complex genera in the family Rosaceae. Morphology of pollen grains (equatorial and polar axes length, shape and size, aperture position, exine sculpture, perforations) is regarded as one of its main diagnostic features for identification of species and varieties. An attempt was made to fill the gap concerning the pollen micromorphology and ultrastructure of R. idaeus L. using light, scanning, and electron transmission microscopy. This study is a comparative analysis of micromorphological and ultrastructural traits of pollen from six raspberry cultivars. The pollen grains were classified as small or medium of shape prolato-spheroids. The parallel striae in the equatorial view in the exine sculpture were sometimes branched dichotomously in &lsquo, Glen Ample&rsquo, &lsquo, Polka&rsquo, and &lsquo, Polana&rsquo, arcuate in &lsquo, Laszka&rsquo, Pokusa&rsquo, or irregularly overlapping in &lsquo, Radziejowa&rsquo, The width of exine striae of biennial fruiting cultivars was much larger than in repeated fruiting cultivars. In terms of the increasing number of perforations per unit area of the exine surface, the cultivars were ranked as follows: &lsquo, &lt, The thickest tectum, the highest and thickest columellae with the largest distances between them, and the thicker foot layer were demonstrated in &lsquo, The ectoexine constituted on average ca. 78&ndash, 90% of the exine thickness. The findings may constitute auxiliary traits i.a. for identification of related taxa, interpretation of phylogenetic relationships, and pollination biology.

In this presented work, the pollen morphologies of twenty-one taxa, nine of them endemic from Turkey, belonging to the genus Salvia (Lamiaceae: sub-family Nepetoideae: tribe Mentheae: sub-tribe Salviinae), S. aethiopis L., S. argentea L., S. aytachii Vural & Adigüzel, S. blepharochlaena Hedge & Hub.-Mor., S. cadmica Boiss., S. ceratophylla L., S. cryptantha Montbret & Aucher, S. frigida Boiss., S. fructicosa Miller, S. halophile Hedge, S. napifolia Jacq., S. microstegia Boiss. & Bal., S. recognita Fisch. & Mey. S. sclarea L., S. smyrnaea Boiss. S. suffruticosa Montbret & Aucher, S. tchihatcheffii (Fisch. & Mey.) Boiss., S. tometosa Bertol, S. verbenaca L., S. viridis L., and S. wiedemanni Boiss. and collected throughout the Turkey, have been intensively studied by using light (LM) and a scanning electron (SEM) microscopy. The objectives of this study are to investigate the pollen morphologies of twenty-one taxa of Turkish Salvia (nine of which are endemic) and to present similar and different characteristics of the taxa. The investigated whole pollen grains had a structure of both isopolar and radial symmetry. Overall, types of aperture were mostly hexacolpate, but it was also determined that the aperture type of S. viridis was both hexacolpate and octacolpate. The pollen grains had characteristic shapes of spheroidal, suboblate, prolate and subprolate. The exine ornamentation was bireticulate and reticulate-perforate. It was determined by the results of palynological studies that pollen morphology changed amongst these studied taxa. As a conclusion, the results of the present study show that palynological characters such as pollen shape, polar axis length (P), equatorial axis length (E), aperture numbers and types and exine ornamentation, exhibit remarkable differences amongst the studied taxa.

In plants, macroautophagy/autophagy has mainly been associated with stress-related processes but how it impacts normal physiological and developmental processes remains largely unexplored. Pollen germination is the critical first step toward fertilization in flowering plants. It is metabolically demanding and relies on high levels of cytoplasmic reorganization activities to support a dramatic morphological transformation that underlies the development of a pollen tube as the conduit to deliver sperm for fertilization. The role of autophagy in this process remains unclear. Here we provide evidence that pollen germination is accompanied by elevated autophagic activity and successful pollen tube emergence depends on autophagy-mediated cytoplasmic deletion. Genetic and cytological experiments demonstrate that inhibition of autophagy prevents pollen germination while induces the persistence of a layer of undegraded cytoplasm at the germination aperture. Together, these results unveil a novel compartmentalized autophagy. Furthermore, high-throughput comparative lipidomic analyses show that suppressed autophagy-induced inhibition of pollen germination is accompanied by altered profiles of stored and signaling lipids. Proteomic analyses reveal that autophagy likely exert its role in pollen germination via downstream mitochondria-related pathways. These findings reveal a critical role for autophagy in initiating pollen germination and provide evidences for compartmental cytoplasmic deletion being crucial for male fertility. Abbreviations: 3-MA: 3-methyladenine; ATG: autophagy-related gene; Cer: ceramide; CL: cardiolipin; Con A: concanamycin A; DAG: diradylglycerol; GO: gene ontology; HAG: hour after germination; LC-MS: liquid chromatography-mass spectrometry; MAG: min after germination; MDC: monodansylcadaverine; PE: phosphatidylethanolamine; PI: phosphatidylinositol; PLD: phospholipase D; PtdIns3K: phosphatidylinositol 3-kinase; RT-qPCR: quantitative real-time reverse transcription PCR; TAG: triradylglycerol; TEM: transmission electron microscopy; TMT: tandem mass tagging.

The aim of this paper is to investigate the ultrastructural events that occur during pollen grains development, with emphasis in pollen grain wall and tapetum ontogeny in Ziziphus jujuba, Z. mucronata, Paliurus spina-christi (Paliureae) and Gouania ulmifolia (Gouanieae). Anthers at different developmental stages were processed according to classic techniques for transmission electron microscopy. Differences in the number of endothecium layers and in the number of tapetal cell nuclei were found. Tapetal cells present an anastomosing tubular network and large vesicles with fibrillar content in the cytoplasm. Pollen grain development and ontogeny of pollen grain wall are similar in the four species. The number of endothecium layers, the number of nuclei of the tapetal cells and tapetal cells ultrastructure of the four species support the phylogenetic relationships previously published for the Rhamnaceae family. Tapetal vesicles with fibrillar or polysaccharide content seem to be an exclusive characteristic of the tribes Paliureae and Gouanieae. Some ultrastructural characters of the pollen grain wall development are common to other species of Rhamnaceae, such as the primexine matrix present at the microspore mother cell stage, the aperture entirely built up during the tetrad stage, the thick and fibrillar intine, and the granular infractectum.

Pollen morphology of 10 species and foliar epidermal anatomy of eight species of Papilionaceae from Skardu valley, northern Pakistan has been estimated for the first time. The present study was commenced with an aim to provide a detailed account of the pollen morphology by scanning electron microscopy and foliar epidermal anatomy by light microscopy. The pollen aperture was tricolporate with reticulate exine in the selected species. Stomata types are actinocytic, paracytic, and anomocytic. Irregular or polygonal with undulate or straight walls, epidermal cells were reported. A unique diversity was observed in the foliar trichomes that show the taxonomic significance of the discrimination of taxa. Non-glandular trichomes were observed in the selected species which are unicellular with thin, long and pointed apical cells. Pollen and foliar micro morphological characters proved to be helpful for the identification of taxa at a specific level.

Salamah A, Luthfikasari R, Dwiranti A. 2019. Pollen morphology of eight tribes of Asteraceae from Universitas Indonesia Campus, Depok, Indonesia. Biodiversitas 20: 152-159. Asteraceae is one of the largest flowering plant families in the world consisting of a high diversity of species that possess many macro-morphological characters. Ecological pressures have resulted in this highly varied morphology. Our research aims to describe the pollen morphology of the Asteraceae for species occurring in Depok Campus of Universitas Indonesia. Pollens of 14 species from eight tribes were extracted using acetolysis method and observed under a light microscope. The result showed that pollen unity, shape and pollen surface appeared to be differentiating characters of the Asteraceae from other families, while polarity and symmetry characters can be distinguishing characters at higher levels of the family such as subdivisions. Aperture characters were useful to differentiate between tribes. The shape of pores and size of pollen were not useful in differentiating between tribes, but may differentiate between lower taxa. The results of this study could be used as supporting data for regrouping taxa within the Asteraceae using morphological features.

Identification of pollen grains of cultivated plants is essential in archaeobotanical studies. In this study, we investigated the pollen morphology of 30 species which are representatives of most of the crop plants in southern China, using a light microscope. Our results show that the pollen grains of these species or genera can generally be identified by their size, aperture(s) and exine sculpture. We found that: (1) some cultivated cereals can be distinguished from wild species of Poaceae according to their size frequency combined with their morphological features; (2) the lengths of the equatorial diameter (E), polar axis (P) and the greatest dimension of the lumina (the size of the network sculpturing) of the exine reticulum may be diagnostic features to distinguish some brassicaceous vegetables. There are significant differences between the E and P values among Brassica campestris (B. rapa, oilseed rape, Chinese cabbage), B. alboglabra (B. oleracea var. alboglabra, gai lan, Chinese kale), B. parachinensis (B. rapa var. parachinensis, choy sum, Chinese flowering cabbage) and B. chinensis (B. rapa ssp. chinensis, pak choi), but moderate differences in the longer axis length of the reticulum lumina, which provide potential for identifying species on the basis of pollen grains. We compared the P values and the longer axis length of the lumina of modern specimens of Brassicaceae pollen grains with those of fossil pollen extracted from the Ming-Qing cultural layer in the Fuqikou site at Chongqing, China, and found that the fossil pollen grains of Brassicaceae probably represent vegetable plants related to B. parachinensis. Moreover, we measured the diameters of rice pollen grains from modern paddy fields to assess the pollen size frequency and found that the size range from ~ 34 to 38 µm is closely associated with rice pollen in southern China, which can be used to detect pollen signals of human activities in archaeobotanical investigations.

Senecio L., the largest genus in the tribe Senecioneae (Asteraceae), contains a significant number of taxonomic difficulties, given that its boundaries are not clearly defined and species identification is sometimes complicated. A study was carried out to evaluate the importance of micromorphological characters in the resolution of such taxonomic problems. The study included 18 South American taxa from series Xerosenecio, Corymbosi and Otoperi. The characters studied include the stigmatic surface and apices of the stylar branches, the filament collar, base and appendages of the anthers, and the pollen shape, size, sculpture and aperture. The microcharacters of the stamens (filaments and anthers) and the presence of margo in the pollen provide taxonomically useful traits for the differentiation of related taxa and infraspecific entities in the genus Senecio. The mesoaperture in the pollen grain in eight Argentinean taxa of Senecio is recorded for the first time. Finally, unique floral microcharacters (sagittate anther base) and palynological features (cavea not evident, long spines) in S. otites were observed.

A study of pollen and seed morphology of Barleria L. of Yemen that comprises nine species has been carried out. This study utilizes the pollen and seed micromorphological characters to show its taxonomic significance within the genus, and the species studied B. acanthoides, B. aculeata, B. orbicularis, B. parviflora, B. prionitis, B. ventricosa, B. proxima, B. tetracantha and B. bispinosa. Pollen grains are spheroidal, tricolporate, short aperture and circular endoaperture are present. Measurements of lumina, columellae, apocolpium, granules and exine thickness are useful to distinguish species within the genus. Seed coat ornamentation provides a significant character to distinguish this genus which has long or short, straight or twisted and wooly hygroscopic hairs which differ from those of other genera in the family.

This study, the fifth in a series investigating palynological characters in angiosperms, aims to explore the distribution of states for 19 pollen characters on five early diverging orders of Superasteridae (Berberidopsidales, Caryophyllales, Cornales, Ericales, and Santalales) plus Dilleniales. To illustrate the character states found in the pollen of this group, we examined pollen grains of 15 species exemplifying 15 families across all studied orders using light, scanning, and transmission electron microscopy. We reconstructed the phylogeny of the early diverging Superasteridae and related taxa with eight genetic markers for 172 genera, using maximum likelihood (ML) analysis. Nineteen pollen characters were coded for the genera used in this phylogeny and compiled into two morphological matrices using two coding strategies. The characters were then optimized on the newly generated ML tree plus two constrained trees differing in the position of Dilleniales, using three methods of inference. Taxa in this grade show a striking diversity of pollen morphologies, particularly in certain characters such as size, tectum sculpture, and aperture number. The plesiomorphic condition for the early diverging Superasteridae is unambiguously and consistently inferred to comprise monad-dispersed, isopolar, spheroidal, circular in outline, equatorially arranged, tricolpate pollen grains with granular aperture membranes, a smooth tectum, and endexine present. We identify diagnostic character states and synapomorphies for several monophyletic groups, and explore the palynological evidence that may shed light on some unresolved relationships. For example, the hypothesis that Dilleniales is sister to Superrosidae is better supported than alternative hypotheses, being consistent with a number of shared palynological state changes including transitions to presence of costae, reticulate tectum, and columellar infratectum structure. Across this part of the angiosperm phylogeny, most state transitions occur repeatedly, and their frequency varies among both clades and characters. We discuss the impact of optimization method, tree topology, and coding strategy upon ancestral state reconstruction.

Arabinogalactan proteins (AGPs) are extensively glycosylated hydroxyproline-rich glycoproteins ubiquitous in all plant tissues and cells. AtAGP6 and AtAGP11, the only two functionally known pollen-specific classical AGP encoding genes in Arabidopsis, are reported to have redundant functions in microspore development. BcMF18 and BcMF8 isolated from Brassica campestris are the orthologues of AtAGP6 and AtAGP11, respectively. In contrast to the functional redundancy of AtAGP6 and AtAGP11, single-gene disruption of BcMF8 led to deformed pollen grains with abnormal intine development and ectopic aperture formation in B. campestris. Here, we further explored the action of BcMF18 and its relationship with BcMF8. BcMF18 was specifically expressed in pollen during the late stages of microspore development. Antisense RNA transgenic lines with BcMF18 reduction resulted in aberrant pollen grains with abnormal cellulose distribution, lacking intine, cytoplasm and nuclei. Transgenic plants with repressive expression of both BcMF8 and BcMF18 showed a hybrid phenotype, expressing a mixture of the phenotypes of the single gene knockdown plant lines. In addition, we identified functional diversity between BcMF18/BcMF8 and AtAGP6/AtAGP11, mainly reflected by the specific contribution of BcMF18 and BcMF8 to pollen wall formation. These results suggest that, unlike the orthologous genes AtAGP6 and AtAGP11 in Arabidopsis, BcMF18 and BcMF8 are both integral to pollen biogenesis in B. campestris, acting through independent pathways during microspore development.

Cell polarity is essential for generating diverse cell functions. The underlying mechanisms of how a cell establishes, maintains, and changes its polarity are poorly understood. Recently, sterol-rich membrane microdomains are found to be associated with these processes. However, both its exact characteristics and importance are still unclear. Here we show microdomains change dynamically in developing and germinating rice pollen with selective enrichment in the aperture and the tip of newly born pollen tubes by use of the sterol-specific probe filipin. Using the sterol extraction sensitivities of microdomain proteins and quantitative proteomics, we identified 237 microdomain-associated proteins from 934 identified pollen detergent resistant membrane proteins. This proteome includes almost all of the known key regulators comprising the polar growth network, and it shows more similarity to front-back polarized HeLa cells than nonpolarized Arabidopsis suspension cells. We immunolocalize flotilin-like protein, a representative of these sterol-dependent proteins and directly visualize microdomains in pollen. These results indicate the presence of microdomains in pollen and pre-established cell polarity around the aperture during pollen maturation. Our findings reveal an atlas of the microdomain-associated proteome in pollen. This work provides useful resources and knowledge needed to further dissect the mechanisms for the establishment and maintenance of cell polarity.

Product yield and the continuity of the quality of products of plants are in parallel with their ability to tolerate or adapt to environmental factors. For this reason, it is extremely important to determine the changes in the plants under various stress conditions. Male reproductive structures are directly related to product yield and quality, and they're very sensitive to abiotic stress. Stress causes irreversible damage to plants depending on its amount and duration. The aim of this study is to determine the sensitivity of male reproductive structures of soybean seedlings and the critical salt concentration at which fertile pollen grains could be obtained in our soils whose salinity is increasing day by day. The selected soybean seedlings were exposed to increasing salt concentrations (50, 100, 150, 200, 250mM) for 6 months and they were compared with a control group in terms of flowering, pollen morphology (pollen size, exine and intine thickness, aperture structures), pollen viability, pollen germination, and pollen tube length. It was determined that, by affecting the growth process of soybean at varying grades, salt stress causes deformations in the plant's reproductive structures and decreases it's tolerance to salt stress.

Quadripollis krempii was described by Drugg 1967 from Maastrichtian deposits in California and has been reported from the Albian to Paleocene of the western United States and Canada. A revised description is supported by illustrations of specimens found in outcrops of the Straight Cliffs Formation in southern Utah. Q. krempii is unique among fossil tetrads and the tetrahedral tetrad is apparently inaperturate. We observe that the thinning and occasional rupturing of the exine observed by Drugg is a vestigial aperture, herein described as a tenuitas. Q. krempii has been thought to be either gymnospermous or angiospermous. No modern gymnosperms produce pollen in obligate tetrads but at least 23 angiosperm families do. Our review revealed possible families with some similarities to Q. krempii, mainly members of the Juncaceae which exhibit an ulcerated or thinned exine in the distal areas of the monads. A relationship to bryophytes cannot be ruled out.

Pollen morphology of 28 plant taxa belonging to 23 families from Lucknow, India is illustrated and described on the basis of observations from light microscopy (LM) and confocal laser scanning microscopy (CLSM). The principal objective is to observe and document the widespread variation in pollen shape, size, aperture diameter and pollen wall architecture of the studied plant taxa. The pollen morphological characters of 28 plant taxa were subjected to Principal Component Analysis and Hierarchical Component Analysis (PCA and HCA) suggesting four clusters. Cophenetic correlation coefficient also validates the four group clustering. The study will improve precise identification of fossil pollen grains recovered in sediments, thus aid in pollen analysis of the Quaternary deposits in India and also in similar tropical and subtropical regions of the world. Also, the study has implications for comparative morphologic, taxonomic and phylogenic studies. Besides these, preservation potential of different pollen grains has been described on the basis of pollen wall architecture.

Palynological studies on ten species of angiosperms family namely Hibiscus rosa- sinensis L . (Malvaceae), Lilium candidum L. (Liliaceae), Petunia axillaris (Lam.) B.S.P.(Solanaceae) and seven species from family asteraceae namely Artemisia indica Willd. , Aster ageratoides Kitam., Calendula offcinalis L., Cerpis japonica L. (Benth.), Sonchus asper (L.) Hill , Tagetus patula L., and Taraxicum officinale F.H.Wigg. was carried out. Result obtained from this investigation showed that pollen shape is spheroidal in Artemisia indica, Aster ageratoides, Calendula offcinalis, Hibiscus rosa- sinensis and P. axillaris; elliptical in L. candidum , hexagonal in S. asper and pentagonal in T. officinale ; tricolpater in C.japonica. Pollen aperture is porate in all except in L.candidum where it is elliptic. Pollen wall is echinate in H.rosa-sinensis, A.ageratoides, T. patula; spinulate in P. axillaries, T. officinale, S. asper, C. japonica, C. officinalis and T. officinale and smooth in L. candidum . The general appearance of the pollen grain is circular in P . axillaries but longer than wide in L.candidum . The circular, echinate, large and triporate pollens seem to be primitive ones and spharoidal, hexaporate features have been regarded as comparatively advanced ones. Polyporate pollens are considered to be secondarily derived. The nature of the pollen grain in these species could be evolutionary significance. The similarities in structure of the pollen grain showed the inter- species relationships among the species and that’s why put in same family while the differences in structures showed reasons for them to exist as distinct species. Only one species namely L.candidum from monocot family (Liliaceae) included in this study. Int. J. Appl. Sci. Biotechnol. Vol 5(3): 361-365