Features Of Pollen Grains Research Articles

Comparative Morphology of the Leaf Epidermis in <i>Ligusticum</i> (Apiaceae) from China

To investigate the taxonomic value of leaf epidermal characters in developing a classification for Ligusticum (Apiaceae), thirty-eight species (including a cultivar) of the genus were examined using both light and scanning electron microscopy. Our results show that the infrageneric classification of Ligusticum based on the characters of involucel bracteoles, mericarps, and pollen grains was not supported as few epidermal characters were relatively constant at section level. Evidence from leaf epidermis, similar to that from molecular and morphological data, supports the separation of Tilingia (i.e. L. ajanense and L. tachiroei) from Ligusticum. Ligusticopsis was found to be indistinguishable from Ligusticum in epidermal characters. Furthermore, results from epidermal analysis, together with that from cytological evidence, fruit morphology as well as molecular phylogenetics suggest that L. delavayi should be transferred out of Ligusticum.

Morphological Study of Pollen Grains and Seeds in Eight Species from the Family Cruciferae in Iraq

The shape dimensions and characteristics of pollen grains and seeds have importance in distinguish among species. Therefore, the present study included morphological characteristics of pollen grains and seeds for eight species belonging to eight genera of the family Brassicaceae and these species are: Alliaria petiolata (M.Bieb) Cavara et Grand, Aubrieta parviflora Boiss, Cardamine hirsuta L., Crambe orientalis L., Eromobium aegyptiacum (Spreng.) Schweinf.et Asch.ex Boiss., Parlatoria cakiloidea Boiss., Sterigmostemum sulphureum (Banksetsol.) Bornm. Neotorularia torulosa (Desf.) Hedge & J. Leonard. The pollen grains were studied in morphological and full measurements were taken, the study showed that the majority of the pollen grains was tricolpate and shape was determined to be prolate, sub prolate and prolate spheroidal. In terms of size, the pollen grains of the studied species varied between small size, medium size, the basic surface pattern of the studied pollen grains was reticulate. The study showed that the morphological characteristics of the seeds varied in shape between oblong-elliptic, lenticular- discoid, ovoid, suborbicular and obovoid. The location of hillum was a difference between terminal and basal position and the surface sculpture of the seed surface varied between a longitudinal striate prominent, faintly reticulate, reticulate, pustular, faintly reticulate and pustular and a smooth. The seeds also varied in color and dimensions, existence of wing in the studied species.

Pollen morphology of certain species of the family Lamiaceae in Saudi Arabia.

The intention of the present wok is to provide an account on the pollen morphological features of Lamiaceae in Saudi Arabia as a basis for future studies of Lamiaceae pollens in the region. Pollen morphology of 20 species belong to 16 genera of the Lamiaceae has been investigated using Light Microscope (LM) and Scanning Electron Microscope (SEM). The study revealed that the pollen grains were characterized by 3-zonocolpate or 6-zonocolpate. Size of the pollen is variable between the genera but not among the species of the same genus. The surface pattern of the exine varies from fine reticulate, rough reticulate, mega-reticulate, reticulate-perforate, bireticulate-perforate or granulate, leading to 6 types of pollen grains. These variations revealed by this study implies that pollen Morphology may be of significant value sharing in solving problems in the classification of Lamiaceae members. A Key to the species, based on the morphological features of pollen grains, is also provided.

Morphological Study of Pollen Grains and Seeds in Eight Species from the Family Cruciferae in Iraq

The shape dimensions and characteristics of pollen grains and seeds have importance in distinguish among species. Therefore, the present study included morphological characteristics of pollen grains and seeds for eight species belonging to eight genera of the family Brassicaceae and these species are: Alliaria petiolata (M.Bieb) Cavara et Grand, Aubrieta parviflora Boiss, Cardamine hirsuta L., Crambe orientalis L., Eromobium aegyptiacum (Spreng.) Schweinf.et Asch.ex Boiss., Parlatoria cakiloidea Boiss., Sterigmostemum sulphureum (Banksetsol.) Bornm. Neotorularia torulosa (Desf.) Hedge & J. Leonard. The pollen grains were studied in morphological and full measurements were taken, the study showed that the majority of the pollen grains was tricolpate and shape was determined to be prolate, sub prolate and prolate spheroidal. In terms of size, the pollen grains of the studied species varied between small size, medium size, the basic surface pattern of the studied pollen grains was reticulate. The study showed that the morphological characteristics of the seeds varied in shape between oblong-elliptic, lenticular- discoid, ovoid, suborbicular and obovoid. The location of hillum was a difference between terminal and basal position and the surface sculpture of the seed surface varied between a longitudinal striate prominent, faintly reticulate, reticulate, pustular, faintly reticulate and pustular and a smooth. The seeds also varied in color and dimensions, existence of wing in the studied species.

Палиноморфологические особенности таксонов рода Geranium (Geraniaceae) Алтайской горной страны

Pollen grains of 22 taxa from 7 sections and 2 subgenera of the genus Geranium from the territory of the Altai Mountain Country and 9 other species of the genus growing outside the study area were examined with the help of scanning electron microscope. The pollen of 10 taxa was studied for the first time. The pollen grains of all studied Geranium taxa are radially symmetric, isopolar, simple, 3-(rarely 4)-groove-ore, oblate-spheroidal or round-ellipsoidal, with pole three-(rarely four-)lobed, with equator almost round. It is shown that common character for all investigated Geranium taxa is clavate sculpture of the first row of the exine. For the first time for the genus Geranium the species G. regelii with 4-lobed, 4-groove-ore pollen grains was identified. It is shown that the features of pollen grains have a value for the taxonomy of Geranium species . Descent groups in sections Geranium and Recurvata according the pollen grains features were revealed. 3 descent groups (groups of G. sylvaticum, G. albiflorum, G. pseudosibiricum) are in the section Geranium, 2 descent groups (groups of G. pratense and G. collinum) are in the section Recurvata. Studied species of the genus Geranium differ on a set of features: the length of polar axis and equatorial diameter, the sculpture of the exine, size, shape and surface of heads, ornamentation of the surface of pollen grains. The size of pollen grains has sectional value and correlate with the size of the corolla: the pollen grains of species in section Recurvata have the largest sizes; the pollen grains of species in the section Batrachioides have the smallest size. Peculiarities of the internal reticle of the exine and the ornamentation of the surface of the pollen grains have subsectional value. The surface sculpture of the clavate heads can be a feature for division of species

Novelties in <I>Tapura</I> (Dichapetalaceae) from the Brazilian Atlantic Forest

A taxonomic treatment of Tapura from the Brazilian Atlantic Forest is presented. Tapura follii is endemic to Espirito Santo State and the distribution of T. wurdackiana is expanded to northeastern Brazil. Two new species, T. martiniae and T. zei-limae are described and micromorphological characters of leaf trichomes and pollen grains, analyzed by SEM, are discussed for the group. In addition, the species are compared to T. amazonica, the most widespread species of Tapura. Descriptions, illustrations, distribution maps, and an identification key for the Atlantic Forest species of Tapura are also provided.

Does stronger pollen competition improve offspring fitness when pollen load does not vary?

Competition among pollen grains from a single donor is expected to increase the quality of the offspring produced because of the recessive deleterious alleles expressed during pollen-tube growth. However, evidence for such an effect is inconclusive; a large number of studies suffer from confounding variation in pollen competition with variation in pollen load. In this study, we tested the effect of pollen competition on offspring performance independently of pollen-load variation. We compared seed mass and early seedling performance in Dalechampia scandens (Euphorbiaceae) between crosses in which variation in pollen competition was achieved, without variation in pollen load, by manipulating the dispersion of pollen grains on the stigmas. Despite a large sample size (211 crosses on 20 maternal plants), we failed to find an effect of pollen competition on seed characteristics or early seedling performance. Paternal effects were always limited, and pollen competition never reduced the within-father (residual) variance. These results suggest that limited within-donor variation in genetic quality of pollen grains reduces the potential benefits of pollen competition in the study population. The lack of paternal effects on early sporophyte performance further suggests that benefits of pollen competition among pollen from multiple donors should be limited as well, and it raises questions about the significance of pollen competition as a mechanism of sexual selection.

Pollen morphology of the southern African tribeTeedieae, an early-branching lineage of crownScrophulariaceae

Mosyakin S. L. & Tsymbalyuk Z. M.: Pollen morphology of the southern African tribe Teedieae, an early-branching lineage of crown Scrophulariaceae. — Willdenowia 45: 65–75. 2015. — Version of record first published online on 13 March 2015 ahead of inclusion in April 2015 issue; ISSN 1868-6397; © 2015 BGBM Berlin-Dahlem.DOI: http://dx.doi.org/10.3372/wi.45.45107The pollen morphology of seven species representing four genera of the tribe Teedieae (Scrophulariaceae) is described and illustrated using light microscopy (LM) and scanning electron microscopy (SEM). Two major pollen types, 3-colporate and 4-colporate, are recognized by aperture types. Within these pollen types, subtypes are distinguished based on exine sculpture, colpi, colpus membrane, and endoaperture characters. Within type I (3-colporate), three subtypes are recognized: Ia — sculpture psilate, rarely with microperforations; Ib — sculpture microperforate and microreticulate; and Ic — sculpture macroreticulate. Type II (4-colporate) is represented by only one subtype IIa — sculpture psilate, rough, and foveolate. The revealed characteristics of pollen grains are taxonomically significant at the generic and specific levels. Our palynomorphological data are consistent with the results of molecular phylogenetic studies. Pollen grains in Teedieae are typically characterized by the colporate aperture type (probably ancestral in Scrophulariaceae) and rather primitive characters of surface and sculpture of colpi membranes. Similar palynomorphological patterns in Teedieae and Buddlejeae can be viewed as ancestral for pollen characters observed in more advanced clades of Scrophulariaceae.

Amount and quality of pollen grains in four olive (Olea europaea L.) cultivars as affected by ‘on’ and ‘off’ years

Olive pollination is anemophilous and an adult olive tree can produce large amounts of pollen grains spread in the air during the flowering period. Viability of pollen grains can be checked by using different methods such as cytoplasmic stains, enzymatic reactions or germination. The aim of the work was to verify either if quality and number of pollen grains were similar in ‘off’ year with respect to ‘on’ year or differences occurred among olive cultivars. In 2006 and 2007, the viability and number of pollen grains per anther have been investigated in four Italian olive cultivars: ‘Ascolana Tenera’, ‘Cazzinicchio’, ‘Cima di Melfi’ and ‘Coratina’. Grains viability was estimated by using three different techniques: acetic carmine, fluorescein diacetate and germination. The three techniques obtained statistically different data, with acetic carmine always showing the highest values but staining also heat-killed pollen grains. Fluorescein diacetate and germination were significantly correlated with a high R2 (0.862). The number of pollen grains significantly varied among the cultivars and between the two years. The average number of pollen grains per anther ranged from 65,722 (‘Ascolana Tenera’) up to 97,160 (‘Cazzinicchio’). A significant difference was detected between the two years for the number of pollen grains per anther, ranging from 98,037 in 2006 (‘on’ year) down to 70,630 in 2007 (‘off’ year). The study also showed that the viability (with all the techniques) of the pollen grains was significantly higher in the ‘off’ year with respect to the ‘on’ one, with important consequences on the fertilization process.

Persicaria wugongshanensis (Polygonaceae: Persicarieae), an odoriferous and distylous new species from Jiangxi, eastern China

Persicaria wugongshanensis, a new species from Wugongshan Mountain, Jiangxi Province in eastern China, is described and illustrated. The new species is a distinctively odoriferous herb characterized by having glandular leaves and tepals, stout inflorescences, dimorphic flowers, extraordinarily long pedicels and densely pitted achenes. A morphological comparison among the new species and its putative relatives, P. hydropiper, P. japonica, P. jucunda and P. odorata, is presented. Comparative micromorphological characters of achenes, leaves, pollen grains and tepals of the new species and its closest relative P. odorata were also presented. Distyly and its ancillary dimorphism were observed and described. The somatic chromosome number (2n = 20) and karyotype formula (2n = 14 m + 6 sm) of the new species were reported.

Изменчивость морфологических признаков тычинок и пыльцевых зерен Platanus x acerifolia (Aiton) Willd. (Platanaceae) в свете задач палеоботаники

The range of the variability of the morphological characters of stamens and pollen grains in Platanus x acerifolia (Aiton) Willd. from different geographical locations — Anapa, Krasnodar region, Russia (group 1) and Santa Cristina, Spain (group 2) was studied. A high degree of conservatism of such stamens features as the form of anthers, the form of pollen sacks, and the prominent apical extension of the connectives for both groups is shown. The shape and degree of pubescence of the apical extension of the connective, as well as the degree of the cutinization of theca are different in two groups. The characters of pollen grains in both groups are quite conservative. The implications of these data for paleobotanical research are discussed.

Качество пыльцы растений как индикатор интенсивности воздействия нефтегазового комплекса на природную среду охраняемых территорий России

Качество пыльцы растений как индикатор интенсивности воздействия нефтегазового комплекса на природную среду охраняемых территорий России

Таксономия Mertensia dsсhagastanica и видов рода Stephanocaryum (Boraginaceae)

Morphological characteristics of the fruit (form of erem and ginobasis), as well as characteristics of pollen grains indicate a close relationship between of Mertensia dschagastanica (Boraginaceae, tribus Trigonotideae) and species of the genus Stephanocaryum (tribus Eritrchieae), which in the «Flora of USSR» refer not only to different genera, but also to different tribes. The genus Stephanocaryum includes 3 species: S. olgae, S. popovii, and S. dschagastanicа. The first two species are closely related and merged into a section Stephanocaryum, and S. dschagastanicа in section Mertensianthe. Genus Stephanocaryum has a hybrid origin, species of which are preserved in Tian-Shan.

Morphological Features of Pollen Grains in Portulaca

The morphological features of pollen grains collected from the broad-leaved and cylindrical-leaved Portulaca species of the Hawaiian Islands were investigated. The variation in size and surface pattern were examined using scanning electron microscopy and statistical analysis. Pollens of the Portulaca were apolar grains of monads exhibiting apertures, colpi, and relatively thin echini. Of particular interest was the differing size of pollen grains among the species studied. Pollens of the broad-leaved Portulaca were considerable in size with a length of about <TEX>$73{\sim}86{\mu}m$</TEX>, while the cylindrical-leaved Portulaca tended to have smaller pollen grains ranging from 50~65 in diameter. The smallest pollens were found in cultivar 2 having an average of <TEX>$43{\mu}m$</TEX>. The pollen was intectate, and the exine surface appeared granulous, having sculptured elements of spinules and puncta. Two types of puncta were discerned; one forming an operculum, and the other, a simple perforation. Numerous spinules and small puncta were found throughout the cylindrical-leaved Portulaca. In the present study, morphological features of pollen grains from ten Hawaiian Portulaca species, including endemic and unknown taxa, revealed the aforementioned pattern of variation. This paper aim to provide morphological information that could be of phylogenetic value within the Hawaiian Portulaca.

Comparison of pollen grain morphological features of selected species of the genusCrataegus(Rosaceae) and their spontaneous hybrids

The aim of our study was to verify, on the basis of statistical analyses of nine quantitative morphological features of pollen grains, the hypothesis that pollen grains of three parental species of Crataegus (C. laevigata, C. monogyna, C. rhipidophylla) differed from the pollen of three spontaneous hybrids of these species (C. × macrocarpa, C. × media, C. × subsphaericea). Contrast analysis revealed that a majority of the pollen features of hybrid species were characterized by significantly higher mean values than those of parental species. Analysis of pollen shape classes indicated that the parental species clearly differed from each other in contrast with hybrids, which were characterized by a similar proportion of pollen in individual pollen shape classes. Statistical analyses showed that the pollen grains of two parental species, C. laevigata and C. monogyna, were most similar to one another. Pollen grains of typical C. rhipidophylla were similar to the pollen of hybrids and the mean values of almost all studied pollen features [P, E, Exp, Exp/P, Le, d, d/E (PAI)] of C. rhipidophylla var. rhipidophylla were intermediate between those of C. monogyna and C. rhipidophylla var. lindmanii. This corroborates Zielinski's conjecture that C. rhipidophylla is probably an old, conserved hybrid between C. monogyna and C. calycina (= C. lindmanii = C. rhipidophylla var. lindmanii). According to the analysis of canonical variables, C. × macrocarpa and C. × media pollen grains were most similar. C. × subsphaericea and C. rhipidophylla var. rhipidophylla and C. rhipidophylla var. lindmanii formed another pair (group), and C. monogyna and C. laevigata constituted separate ‘single species groups’. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 555–571.

Histological and Morphological Studies of Pollen Grains from Elongata, Reduced Elongata and Staminate Flowers in Carica papaya L.

The quality and quantity of pollen from three types of flowers; elongata, reduced elongata and staminate from the commercialized Thai papaya cultivar ‘Khak Nual’ were determined using pollen morphology, pollen physical characters and pollen development processes. Pollen development progressed at the same pace in the three types of pollen-producing flowers and was consistent with pollen development in many angiosperms. Pollen morphology showed that papaya pollen grains are tricolporate, with three apertures, and there is no significant difference in diameter (25.18–25.72 μm) and weight (11.76–15.45 ng) among pollen sources. The staminate flower shows the lowest amount of pollen, with 12,368 pollen per anther, but higher viability and germination rates of 95.53 % and 53.64 %, respectively. In contrast, the elongata type shows the highest amount of pollen grains with 14,884 pollen per anther and the lowest viability and germination rates, 93.06 % and 46.33 % respectively. The physical characteristics of pollen grains from reduced elongate and elongate flowers are similar. Reduced elongate flower type can donate pollen without self-pollinating.

Relationship between pollen morphology and chromosome numbers in Brazilian species of Lippia L. (Verbenaceae)

The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen grains and a single species exhibited, only tetracolporate pollen. The amb ranged from triangular to square, and the shape varied from oblate-spheroidal to prolate-spheroidal. Three different types of exine ornamentation were observed: psilate, scabrate and perforate. In addition to morphological data, we found positive association between the chromosome numbers and size of pollen grains, and also between the length and width of the colpi. The results indicate that the characteristics of pollen grains in Lippia may be used as an additional taxonomic character of the genus.

Taxonomic revision of theQuercus brantiicomplex (fagaceae) in Iran with emphasis on leaf and pollen micromorphology

Micromorphological characters of leaves and pollen grains of the Quercus brantii complex (including seven species and five varieties), as the main species in the Zagros Forests of Iran, were studied by scanning electron microscopy. In order to define the diagnostic value of leaves and pollen grains for species delimitation, multivariate discriminant analysis was applied to micromorphological quantitative features. The results were combined with qualitative characters of pollen grains to separate the examined taxa. Five taxa were confirmed within this complex: Q. brantii var. brantii, Q. brantii var. belangeri, Q. persica, Q. saii and Q. ungeri. The macro- and micromorphological characters of the accepted taxa and their geographical distribution were described. Based on the present results, leaf epidermal characteristics and pollen features are useful taxonomic characters that can help to delimit different taxa within the Q. brantii complex in Iran.

Morphological and anatomical characteristics of Artemisia absinthium var. absinthium and its Polish endemic variety A. absinthium var. calcigena

The presented studies are focused on the comparative morphological and anatomical analyses of two wormwood varieties, i.e. the typical variety Artemisia absinthium var. absinthium and var. calcigena, endemic to the Pieniny Mountains (Western Carpathians). The studies comprise descriptions of the characteristics of pollen grains and the achene surface, analyses of seed germination rate and slime formation, stem anatomy, and leaf morphology and anatomy. The pollen grain surface is typical for the whole Artemisia genus. The seed coat consists of proper epidermal cells and slime cells, whose presence is related to the ability to form slime in both taxa. The obtained results show some typical xeromorphic features in the stem and leaf structure, which are more strongly pronounced in A. absinthium var. calcigena than in var. absinthium. These features include a continuous periderm layer and lignified pith cells developed in the early stages of growth. Although some differences between the studied taxa exist (e.g., better germination power, number of flower heads, length of pedicels and anatomy), they are rather a manifestation of phenotypic plasticity and habitat influence than the taxonomic identity. Based on the results we can state that A. absinthium var. calcigena presents a low position as an independent taxonomic unit and may exemplify a local phenotypic form.

Palynomorphological features of Suaeda acuminata (C.A. Mey.) Moq., Suaeda prostrata Pall. and Tamarix ramosissima Ledeb.

The pollen morphology of Suaeda acuminata, S. prostratа and Tamarix ramosissima from Ukrainian flora has been studied with light and scanning electron microscopy. The main morphological features of pollen grains of three taxa, which spread within halophytes vegetation, are determined. The results has considered as potential useful for identification of the fossil pollen under paleopalynological or paleoecological study.