Study Of Pollen Morphology Research Articles

Oсобенности морфологии пыльцы видов подрода Irisрода Iris L. (Iridaceae) флоры Армении

The study of pollen morphology of 9 representatives of the subgenus Iris (Iris L., Iridaceae) of the Armenian flora was carried out. Pollen grains of all the studied species are anasulcate, large; the exine ornamentation in most species is reticulate. For the species I. pumila L., a densely finely verrucate exine ornamentation with clavate outgrowths was revealed.

Comparative pollen morphology of the Kirengeshoma (Hydrangeaceae)

The genus Kirengeshoma, in the family Hydrangeaceae, is considered by some botanists to be monotypic while others divide it into two species, K. palmata, native to Japan and China, and K. koreana, native to South Korea. We have conducted a comparative pollen morphological study of five populations of the two putative species to investigate this question. Pollen morphological characteristics were observed with scanning and transmission electron microscopy. The pollen characteristics of all five populations were similar. All populations dispersed pollen as the monad and the pollen grain shape were either spheroidal or sub-spheroidal and approximately 12 to 18 µm in diameter, falling in the small grain category. In all five populations, the pollen grains were iso-polar and radio-symmetrical, with tri-colporate apertures. Additionally, pollen surface sculpture patterns of all populations were semi-tectate and reticulate. As a result, the two putative species differed in that the pollen grains of K. palmata were smaller, and their endexine slightly thicker, than those of K. koreana. Despite these differences, we conclude that the similar pollen morphology of all the populations does not support separating them into two independent species. However, different species of angiosperms often have similar pollen morphology. Therefore, we suggest that the genus should be considered to consist of these two independent species unless further morphological or molecular evidence to the contrary is forthcoming.

ELECTRON MICROSCOPIC STUDIES OF SOME ANTICANCER PLANTS POLLEN GRAINS

Pollen is appropriately referred by some as Golden dust extremely valuable on account of their tremendous applications in science, industries and public health. No other plant part even though extremely tiny in size is packed with so much information and power. Similar to other plant parts, pollen characters are so varied that the classification system of plants can be built up entirely on the basis of pollen morphology.Palynology is the distinct branch of biology that deals with the dispersed microscopic tiny living and fossil entities including pollen grains, spores, algal and fungal fragments and others. An important aspect of Palynology is the Pollen morphology. The importance of Palynology in taxonomic and phylogenetic consideration of plants is well known. The changes occurring through hybridization and years of cultivation are reflected in pollen morphology. The scope and interest in the study of pollen morphology have widened with the advent of Scanning Electron Microscopy (SEM) and with regards to unipalynous taxa particularly the understanding of finer morphology is of fundamental importance. SEM gives a correct understanding of exine surface as the electron photographs of the surface replica of the exine provides the exact picture of the ornamentation pattern. The variation in the pollen morphological characters helps in the classification of plant taxa and their assessment of their phylogenetic relationship. In the present investigation, the pollen morphological studies were carried out of some ethnomedicinal plants like Catharanthus roseus, Allamanda cathartica, Datura metel, Brassica juncea, Raphanus sativus and Cleome viscosa pollen grains by Scanning electron microscopy. All that they possess anticancer characteristics in common.

Palyno-morphological characterization of selected allergenic taxa of family Poaceae from Islamabad-Pakistan using microscopic techniques.

Statistics around the world show an increased risk of high allergies associated with plants. The role of allergenic pollen is now well known. The most serious allergenic diseases are asthma and rhinitis, which affect 5-30% of the population of industrialized countries. This work focuses on the exploration of allergenic grass species of Islamabad, Pakistan and use microscopic techniques to correctly identify them. This study contains 11 species of grasses which showed variations in pollen morphological features. The dominant pollen shape was prolate, prolate-spheroidal and sub oblate. The largest polar diameter was calculated for Echinochloa crus-galli (56.00 μm) while the largest equatorial diameter was found in Cenchrus ciliaris (45.00 μm). Exine ornamentation varied from Gemmate-verrucate, Scabrate-reugulate, Verrucate-reticulate, Gemmate-Scabrate, Fine-Gemmate, Gemmate-rugulate, Gemmate-reticulate, Gemmate-scabrate, Scabrate-verrucate, and Scabrate. Maximum exine thickness was found in Eleusine indica (4.90 μm) while in C.ciliaris (1.50 μm) the minimum thickness of exine was measured. In E.crus-galli (1.54 μm), the largest P to E value was measured and the smallest value was noticed in Setaria verticillata (0.86 μm). The study was performed with an aim to identify the allergenic plant species in Islamabad-Pakistan using pollen morphological studies. This study provides significant information, to arrange the pollen types within their defined classes and to discuss various pollen features for developing an allergenic pollen atlas.

Comparative pollen morphology studies on some species of Brassicaceae in Turkey

Pollen aperture type, shape, size, polar axis length, equatorial axis length, P/E ratio, colpus length, thickness of the sexine and nexine, S/N ratio, ornamentation type, and lumen shape and width were determined by using light and scanning electron microscope. A multivariate analysis was carried out using the Gover’s general similarity coefficient and UPGMA based on 3 qualitative and 8 quantitative pollen characters for 43 taxa belonging to 30 genera and 19 tribes. In all of the taxa studied, the pollen grains were generally small or medium-sized, tricolpate, except in Matthiola longipetala, with an inconspicuous aperture. The shape varied from prolate-spheroidal to perprolate. The exine ornamentation was microreticulate, reticulate, or macroreticulate. In some species, reticulate ornamentation was found together with microreticulate, and in some others, with macroreticulate ornamentation. It was seen that some taxa belonging to some genera placed near each other in the dendogram partially supported some tribes, such as Brassiceae, Alysseae, Sisymbrieae, and Camelineae. It is notable that some closely-related tribes were placed near each other on the dendrogram, which partially supports some previous molecular studies. In addition to exine ornamentation, the pollen size, shape, sexine and nexine thickness, and colpus length were the most useful characters. These characteristics can be used to identify and distinguish some genera, species and partly tribes within the family. They also provide detailed information on the pollen grains of some Brassicaceae taxa, some of which were studied herein for the first time, and this knowledge will be useful for comparisons in future pollen studies.

Pollen Morphological Studies of some Common Garden Plants of Apocynaceae Family

Pollen Morphological Studies of some Common Garden Plants of Apocynaceae Family

Study of Petiole Anatomy and Pollen Morphology of Five Species of Senna Mill. From Bangladesh

Abstract Not Available
 Dhaka Univ. J. Biol. Sci. 29(2): 245-252, 2020 (July)

Comparative foliar anatomical and pollen morphological studies of Acanthaceae using light microscope and scanning electron microscope for effective microteaching in community.

In this study, foliar anatomy and pollen morphology of 10 species of Acanthaceae has been investigated using light and scanning electron microscopy. The study was aimed to highlight the role of microscopy in microteaching at community for proper characterization of plants using palyno-anatomical characters including pollen type, exine sculpturing, shape of epidermal cells, pattern of anticlinal wall, type and size of stomata, and trichome. Most of the species have polygonal cell shapes but some species have irregular, tetragonal, and pentagonal shape of epidermal cells. The largest epidermal cell length on adaxial and abaxial surface were observed in Asystasia gangetica 66.95 and 87.40 μm whereas least was observed on adaxial surface in Justicia adhatoda 36.9 μm and on abaxial surface in Barleria cristata 35.65 μm. In anatomy, species have diacytic type of stomata, whereas stomata of paracytic type observed in two species, while in A. gangetica cyclocytic type of stomata are present. Quantitively on abaxial surface, largest stomata length 29.9 μm and width 24.30 μm was noted in B. cristata. While shortest stomata length was observed in Ruellia prostrata 25.95 μm whereas minimum width of stomata was examined in Barleria acanthoides 2.05 μm. The diversity of trichomes are present in all species except in Ruellia brittoniana. Acanthaceae can be characterized by exhibiting different pollen morphology having five types of pollen shapes, prolate, spheroidal, perprolate, subprolate, and oblate spheroidal. Exine peculiarities showing variations such as reticulate, granulate, coarsely reticulate, lophoreticulate, perforate tectate, and granulate surface were examined.

Myrtaceae pollen morphology study from Bass Strait islands, Australia, is effective in separating region-specific fossil Myrtaceae pollen types

The identification of Myrtaceae pollen to species level in fossil records has challenged palynologists due to the similarity of pollen grains produced by species in this family. Here, we present a pollen morphological study of the Myrtaceae species found in a specific region of southeastern Australia, the islands of the Furneaux Group in Bass Strait, and apply this to fossil pollen records from the same region to confirm its utility in differentiating Myrtaceae pollen to type level. We examined 23 species of Myrtaceae, belonging to 6 genera, and were able to identify 11 distinct types. The observed Myrtaceae pollen taxa can be confidently separated to genus level, apart from Euryomyrtus, which is indistinguishable from Leptospermum. Specifically, separation to species level is most achievable within the genus Melaleuca, as well as Kunzea and Calytrix, which are each represented by a single species. Conversely, Eucalyptus could only be separated into major types, while Leptospermum species could not be clearly separated, although differences in exine patterns exist. We also demonstrate that our pollen morphological types can be applied to Holocene and Pleistocene fossil records from the Furneaux Group. We recommend that studying the Myrtaceae of a specific area is more helpful in identifying fossil Myrtaceae pollen from that area than using general Myrtaceae pollen morphological descriptions or keys that are not site- or region-specific.

Pollen morphology applied to species delimitation of Myrsine (Myrsinoideae-Primulaceae)

Myrsine, a genus in the family Primulaceae, includes closely related species whose taxonomic identification is difficult. Morphological analysis of pollen grains has provided key information for the classification of Primulaceae, helping clarify the taxonomy of several genera, subgenera, and species. However, a detailed study of pollen morphology in Myrsine was still lacking. Therefore, in this study, we investigated the potential of pollen characters to be used for the specific delimitation of Myrsine. Acetolyzed pollen grains were examined using light microscopy and non-acetolyzed pollen grains were analyzed by scanning electron microscopy. Pollen grains and monads of all analyzed species were isopolar, small to medium in size, and prolate spheroidal, subprolate, or prolate in shape, with (3)-4-colporate apertures, regular colpi or loxocolpi, and reticulate-granulate, granulate, rugulate-granulate, or microreticulate exine. Species considered difficult to identify based on other morphological traits were successfully distinguished using quantitative and qualitative pollen characters, confirming the importance of pollen morphology as a source of taxonomic information. Also, Myrsine stands out among genera of the subfamily Myrsinoideae because it shows great interspecific pollen variation, including two class sizes of pollen grains, three types of exine ornamentation, and exclusive loxocolporate pollen with inconspicuous endoapertures. This is the first report of loxocolporate pollen in Primulaceae.

Study of pollen morphology and salinity effect on the pollen grains of four olive (Olea europaea) cultivars

Pollen and seed germination tests can be used as effective test in screeing salt-tolerant crop and pollen grain morphology characteristics can be used to determine interspecific and intraspecific relationships among olive species. So, This study was conducted to investigate the effect of different salinity concentrations on pollen germination, tube growth and further evaluation of pollen grain morphological characteristics using Scanning Electron Microscopy (SEM) of four olive (Dezful, Mission, Koroneiki and Tarom2) cultivars. Results showed that polar axis (P), equatorial axis (E), and the distance between furrow edges and ridges width were significantly different between four olive cultivars. The value of polar axis ranged from 18.77 μm in ‘Koroneiki’ up to 20.03 μm in ‘Dezful’, while the mean values of equatorial axis ranged from 12.76 μm for ‘Tarom2’ up to 13.68 μm for ‘Dezful’. The lowest distance between furrow edges (12.13 μm) and width of ridges (8.63 μm) were obtained in ‘Mission’ cultivar. It indicated that ‘Dezful’ and ‘Mission’ olive cultivars produced pollen grains with low mesh density in unit area and incomplete closure. While, ‘Tarom2’ and ‘Koroneiki’ produced pollen grains with high mesh density and complete closure. The results also elucidated that the amount of pollen germination decreased as concentration of salinity increased on the medium. The reduction of pllen germination rate occurred at the 83.71%, 96.68%, 86.83% and 87.38% with additional of 25 mM NaCl in the media of ‘Tarom2’, ‘Dezful’, ‘Mission’ and ‘Koroneiki’ cultivars, respectively. The maximum pollen tube length (171.99 μm) was observed in ‘Tarom2’ cultivar cultured in a salinity-free medium; while pollen tube length was the lowest (3.5 μm) in ‘Dezful’ cultivar cultured in a medium containing 25 mM of NaCl. Findings also revealed information in which was able to categorize cultivars into tolerant (‘Tarom2’), semi-tolerant (‘Mission’ and ‘Koroneiki’) and sensitive (‘Dezful’) based on tolerating critical salinity (lethal salinity) condition at the pollen germination stage. According to the results of this experiment, it can be concluded that investigate the effect of salinity stresses on gametophytic phase could be applied for the screening tolerant olive cultivars to salt stresses.

Pollen morphological study on some rare Allium L. (Amaryllidaceae) taxa in Turkey

The pollen morphology of 10 Allium L. taxa, 6 of which are endemic to Turkey, were investigated in detail by light and scanning electron microscopy. According to LM and SEM, the pollen grains of genera were monad, monosulcate percolate, heteropolar with bilateral symmetry, 25.30 to 53,85 µm long axis (LA) and 17.55 to 36.86 µm short axis (SA), the form was prolate (mean of LA/SA ratio 1.30 to 1.70 and in polar view boat-shaped. Three types of ornamentation were determined. Striate-rugulate-perforate type in Allium longisepalum, A. oreophilum, A. anacoleum, A. microspathum, A.shirnakiense, A. purpureoviride and A. armenum, Rugulate–perforate type in A. pervariense and A. gabardagense and Rugulate–reticulate-perforate type in A. arlgirdense. Sulcus membrane ornamentations were rugulate or psilate. The sulcus extends from the distal to proximal ends in A. anacoleum, A. arlgirdense and A. pervariense. The present study on some Turkish species of Allium showed that several morphological pollen characters may possess taxonomical value.

Pollen morphology of Bignoniaceae from Brazilian forest fragments and its systematic significance

Bignoniaceae Juss. are widely distributed in tropical and subtropical regions. Most of their Neotropical species have a climbing habit, which makes the family one of the most ecologically important in the Americas. This study of pollen morphology from 23 Bignoniaceae species in Brazilian forest fragments aimed to investigate new pollen characteristics of the family by light and scanning electron microscopy, which can assist in delimitating Bignoniaceae species and taxonomy. Another aim of the study was to analyze the evolution of the family’s pollen characteristics. The pollen grains were acetolyzed, measured and photographed. We describe the pollen grains based on qualitative data, and quantitative data were analyzed using descriptive and multivariate statistics. Based on the qualitative data, an ancestral reconstruction of pollen morphology characteristics was performed for the taxa analyzed. We used the pollen data to understand the relationships established by previous phylogenies. The pollen grains are monads or tetrads, apolar or isopolar, and medium to large, with circular, subcircular to subtriangular amb; oblate to oblate-spheroidal; inaperturate, 6-colpate, (7)-8-(9)-colpate or 3-colporate with short or long colpi that are narrow, wide or very wide and with or without margo; lalongate endoapertures sometimes not evident; and psilate perforate, microreticulate or reticulate exine, homo- or heterobrochate, with simpli or duplicolumellate muri. This result confirms Bignoniaceae as a eurypalynous family, and it allows the identification of pollen morphological characteristics shared by genera and species studied.

Pollen morphology study of Leguminosae family from Manchippa Reserve Forest, Nizamabad district, Telangana

Pollen morphology study of Leguminosae family from Manchippa Reserve Forest, Nizamabad district, Telangana

Comparative study of pollen morphology and exine ultrastructure in tetrads, octads and polyads of the genus Mimosa (Leguminosae)

ABSTRACTThis is the first study of exine ultrastructure to be performed in five endemic Mexican Mimosa taxa (M. pringlei var. pringlei, M. calcicola, M. spirocarpa, M. caerulea and M. sousae), one occurring in Mexico and Central America (M. occidentalis), one widely distributed throughout the neotropics (M. setosa var. paludosa), and two in South America (M. irrigua and M. daleoides). Mimosa pollen grains are associated in polyads (12 grains), octads and tetrads. Polyads and octads in members of the basal clade of Mimosa phylogeny (sect. Mimadenia) evince the affinity of Mimosa with Piptadenia. Octads are retained in sect. Batocaulon and tetrads are evolved in this section. More recent clades (sect. Habbasia, Mimosa and Calothamnos) only show tetrads varying in size and shape. Polyads show greater variation in the exine layers, with a bistratified granular structure. Octads display a columellar-granular infratectal structure while tetrads in sect. Mimosa exhibit a less variable exine with a granular infratectal structure.

Comparative pollen morphology studies of two endemic noccaea moench (brassicaceae) taxa from Turkey

This study is supporting the biological characteristics of the plants to put forward more efficient systematic and evolutionary relationships by pollen morphology study. It is aimed to determine the comparative palynological features of the two endemic taxa from Brassicaceae family which are naturally growing in Turkey. Detailed morphological investigation of the pollen of the Turkish Noccaea elegans (Boiss.) Al-Shehbaz and N. cilicica (Schott & Kotschy ex Boiss.) Al-Shehbaz were carried out under Light Microscope and Scanning Electron Microscope (SEM). The results are described here for the first time. It was revealed that the pollen grains of two endemic taxa were the tricolpate type and spheroid/suboblate shaped. Exine was seen to be semitectate- reticulate ornamentation. Comparisons which will be made with the collected species and other taxa within the family will make contribution to taxonomy for family

A continuous morphological approach to study the evolution of pollen in a phylogenetic context: An example with the order Myrtales.

The study of pollen morphology has historically allowed evolutionary biologists to assess phylogenetic relationships among Angiosperms, as well as to better understand the fossil record. During this process, pollen has mainly been studied by discretizing some of its main characteristics such as size, shape, and exine ornamentation. One large plant clade in which pollen has been used this way for phylogenetic inference and character mapping is the order Myrtales, composed by the small families Alzateaceae, Crypteroniaceae, and Penaeaceae (collectively the “CAP clade”), as well as the large families Combretaceae, Lythraceae, Melastomataceae, Myrtaceae, Onagraceae and Vochysiaceae. In this study, we present a novel way to study pollen evolution by using quantitative size and shape variables. We use morphometric and morphospace methods to evaluate pollen change in the order Myrtales using a time-calibrated, supermatrix phylogeny. We then test for conservatism, divergence, and morphological convergence of pollen and for correlation between the latitudinal gradient and pollen size and shape. To obtain an estimate of shape, Myrtales pollen images were extracted from the literature, and their outlines analyzed using elliptic Fourier methods. Shape and size variables were then analyzed in a phylogenetic framework under an Ornstein-Uhlenbeck process to test for shifts in size and shape during the evolutionary history of Myrtales. Few shifts in Myrtales pollen morphology were found which indicates morphological conservatism. Heterocolpate, small pollen is ancestral with largest pollen in Onagraceae. Convergent shifts in shape but not size occurred in Myrtaceae and Onagraceae and are correlated to shifts in latitude and biogeography. A quantitative approach was applied for the first time to examine pollen evolution across a large time scale. Using phylogenetic based morphometrics and an OU process, hypotheses of pollen size and shape were tested across Myrtales. Convergent pollen shifts and position in the latitudinal gradient support the selective role of harmomegathy, the mechanism by which pollen grains accommodate their volume in response to water loss.

Pollen Morphological Studies in Five Species of Cyperus from Cyperaceae of Wardha District, Maharashtra, India

Pollen Morphological Studies in Five Species of Cyperus from Cyperaceae of Wardha District, Maharashtra, India

Pollen morphology and post-tetrad wall development in the subfamily Fumarioideae (Papaveraceae)

The subfamily Fumarioideae is the most diversified group of the Papaveraceae family, a eurypalinous group whose pollen information has classically been used for studying systematic issues. In this paper we present a study of pollen morphology and development of the pollen wall in most of the Fumarioideae genera excluding Hypecoum. We describe a high variability in pollen grain ornamentation and in aperture shape and number among genera of the subfamily. Remarkable features of the pollen-wall layer development in Fumarioideae are a lamellated foot layer at the young microspore stage and a granular infratectum. In the apertures, the aperture membrane formed by ectexine is absent for the subtribe Fumariinae, and the ultrastructure of the exinous oncus shows that the endexine is arranged in three different ways among the Fumarioideae representatives. From vacuolate microspore stage onward the apertures of most Fumarioideae genera are covered by a fluffy plug, while during young bicellular stage the intine under the apertures develops from the material that accumulated in the periplasmic space. We have identified significant differences between the pollen features of the tribe Fumarieae and the tribe Hypecoeae, such as psilate exine and granular infratectum. The presence of atypical pollen features in Fumarioideae is discussed within the framework of current knowledge of pollen wall development, highlighting their implications for a better understanding of pollen wall evolution.

Morfologia polínica de espécies das tribos Ipomoeeae Hallier f. e Merremieae D.F. Austin (Convolvulaceae) ocorrentes numa região de ecótono do município de Caetité, BA, Brasil

RESUMO O estudo da morfologia polínica das espécies das tribos Ipomoeeae e Merremieae (Convolvulaceae) tem como finalidade contribuir com a ampliação do conhecimento palinológico dos táxons estudados e subsidiar a taxonomia do grupo. Foram examinados os grãos de pólen de 10 espécies de Ipomoea, uma de Turbina (tribo Ipomoeeae) e quatro de Merremia (tribo Merremieae) ocorrentes na flora de Brejinho das Ametistas, Caetité, BA, Brasil. Os grãos de pólen foram acetolisados, mensurados, descritos e ilustrados sob microscopia de luz (ML) e eletrônica de varredura (MEV). Mediante a análise da morfologia polínica dos táxons estudados, foi possível confirmar o caráter euripolínico do grupo e reconhecer dois tipos polínicos com base no tipo apertural e na ornamentação da exina: Tipo 1. grãos de pólen pantoporados, equinados; Tipo 2. grãos de pólen 3-6-colpados, microequinados, granulados.