scholarly journals Classification of grass pollen through the quantitative analysis of surface ornamentation and texture

2013 ◽  
Vol 280 (1770) ◽  
pp. 20131905 ◽  
Author(s):  
Luke Mander ◽  
Mao Li ◽  
Washington Mio ◽  
Charless C. Fowlkes ◽  
Surangi W. Punyasena

Taxonomic identification of pollen and spores uses inherently qualitative descriptions of morphology. Consequently, identifications are restricted to categories that can be reliably classified by multiple analysts, resulting in the coarse taxonomic resolution of the pollen and spore record. Grass pollen represents an archetypal example; it is not routinely identified below family level. To address this issue, we developed quantitative morphometric methods to characterize surface ornamentation and classify grass pollen grains. This produces a means of quantifying morphological features that are traditionally described qualitatively. We used scanning electron microscopy to image 240 specimens of pollen from 12 species within the grass family (Poaceae). We classified these species by developing algorithmic features that quantify the size and density of sculptural elements on the pollen surface, and measure the complexity of the ornamentation they form. These features yielded a classification accuracy of 77.5%. In comparison, a texture descriptor based on modelling the statistical distribution of brightness values in image patches yielded a classification accuracy of 85.8%, and seven human subjects achieved accuracies between 68.33 and 81.67%. The algorithmic features we developed directly relate to biologically meaningful features of grass pollen morphology, and could facilitate direct interpretation of unsupervised classification results from fossil material.

Phytotaxa ◽  
2021 ◽  
Vol 512 (4) ◽  
Author(s):  
OSMAN TUGAY ◽  
HÜSEYİN DURAL ◽  
BURCU YILMAZ ÇITAK ◽  
KUDDİSİ ERTUĞRUL ◽  
METİN ARMAĞAN ◽  
...  

In the present research, anatomical, palynological and micromorphological characteristics of three endemic Bellevalia species (B. gracilis, B. malatyaensis and B. vuralii) for Turkey are carried out. This work reveals the descriptive characteristics of the examined species, and contribute to solving taxonomic problems. Anatomical studies were carried out on cross sections of root, scape and leaf. The metaxylem, the number of root cortex cells, and the number of cortex and sclerenchyma cells in the scape were found to be significant in terms of taxonomy. Pollen grains of all the examined species were monosulcate and heteropolar. In addition, seed and pollen surface ornamentation were photographed under SEM microscopy, which SEM micrographs showed that the exine sculpturing pattern is reticulate-perforate, and pollen muri walls of were different among the examined species. Conversely, seeds showed a general similarity of the surface among the studied species, all showing a reticulate faveolate ornamentation.


Phytotaxa ◽  
2018 ◽  
Vol 372 (1) ◽  
pp. 35 ◽  
Author(s):  
ÖZLEM ÇETIN ◽  
MUSTAFA ÇELIK

In the present study, morphological, micromorphological, palynological and anatomical characteristics of the genera Opopanax and Crenosciadium are reviewed and compared. The genus Opopanax is distributed in southern Europe, the Mediterranean region and Western Asia, and it is represented by three species in Turkey. Crenosciadium is a poorly known monotypic genus from Turkey, recently treated as synonym in Opopanax. Expanded descriptions, phenology, geographic distributions, and images of habitus of Opopanax and Crenosciadium are given. The differences between the two genera are discussed. The pollen morphology of Opopanax and Crenosciadium is studied by SEM and LM. The palynological results confirmed the stenopalynous characteristic of the family Apiaceae, and revealed that the pollen grains of both genera are perprolate in shape. Also fruit surface ornamentation of both genera is typically striate, and epidermal cells are polygonal or elongated in one direction. Cross-sections of mature fruits are examined and a detailed anatomical description is presented. Mericarp shape and width are very useful characters for discrimination between Opopanax and Crenosciadium; mericarp ribs are also very significant characteristics to discriminate both genera. Our findings, together with previous molecular data, clearly indicate that Crenosciadium differs considerably from Opopanax, and therefore it should be accepted at genus rank.


1983 ◽  
Vol 71 (1) ◽  
pp. 106
Author(s):  
H MAASCH ◽  
K HAESELER ◽  
W GEISSLER ◽  
B FISCHER ◽  
U WAHN

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. D. Ávila-Avilés ◽  
N. Torres-Gómez ◽  
M. A. Camacho-López ◽  
A. R. Vilchis-Nestor

Abstract Nature provides remarkable examples of mass-produced microscale particles with structures and chemistries optimized by evolution for particular functions. Synthetic chemical tailoring of such sustainable biogenic particles may be used to generate new multifunctional materials. Herein, we report a facile method for the synthesis of hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template. Silver nanoparticles was biosynthesized using pollen grains as a reduction and stabilization agent as well as a bio-template promoting the adhesion of silver nanoparticles to pollen surface. Fe3O4 nanoparticles were synthesized by co-precipitation method from FeSO4. Hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template were obtained and characterized using Scanning Electron Microscopy and Transmission Electron Microscopy to study the morphology and structure; Energy-Dispersive X-ray Spectroscopy to determine the chemical composition distribution; and Confocal Fluorescence Microscopy to demonstrate the fluorescence properties of hybrid nano-microstructures. Furthermore, these hybrid nano-microstructures have been studied by Surface-Enhanced Raman Scattering (SERS), using methylene blue as a target molecule; the hybrid nano-microstructures have shown 14 times signal amplification.


2012 ◽  
Vol 59 (1) ◽  
pp. 529-538 ◽  
Author(s):  
Krystyna Piotrowska

The measurements of pollen fall were carried out in Lublin in 1995 - 2000 years by the gravimetric method. The modified Durham sampler was applied, located at 9 m above ground level. On the base of results 6 year observations - the pollen calendar for Lublin was prepared. The following 15 plant taxa were taken under consideration: <i>Alnus</i>, <i>Corylus</i>, Cupressaceae, <i>Populus</i>, <i>Fraxinus</i>, <i>Betula</i>, <i>Quercus</i>, Pinaceae, Poaceae, <i>Rumex</i>, <i>Plantago</i>, <i>Urtica</i>, Chenopodiaceae, <i>Artemisia</i> and <i>Ambrosia</i>. The anemophilous plants' pollen season in Lublin began in half of February and lasted till half of September. First appeared pollen grains of decidous tress' and shrubs, then the coniferous. High values of pollen fall of these plants were noted till the end of May. Start of grass pollen season was recorded from the half of May, and at the latter part of this month, also other herbaceous plants. The highest concentrations of pollen were found in April and May when trees and shrubs pollinated. The highest annual totals were marked for plants of the following taxa: <i>Betula</i>, Poaceae, Pinaceae, <i>Alnus</i>, <i>Urtica</i>.


2012 ◽  
Vol 62 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Agnieszka Dąbrowska

Grass pollen allergens are a frequent cause of pollen allergy in Poland and other European countries. The research on aeroplankton conducted in Lublin since 2001 allows characterization of the course of grass pollen seasons and estimation of the effect of maximum and minimum temperatures, relative air humidity, precipitation and maximum wind velocity on the taxon's pollen concentration. The gravimetric method was used in the study. During the eight-year research period, the pollen season usually started in the first or second decade of May and, as a rule, it lasted till the end of August, and quite exceptionally, in 2002 and 2008 till mid-August. The mean length of the pollen season was 107 days. The highest grass pollen risk was observed in the 26<sup>th</sup> and 27<sup>th</sup> week. The highest annual counts reaching over 3600 pollen grains × cm<sup>-2</sup> were noted in 2008, while in the other study years they ranged from 741 to 1909. The date of the pollen season onset and its course were highly dependent on weather conditions, which was confirmed by the statistical analysis. The greatest significant influence on the pollen season was exerted by maximum temperature, relative air humidity and the maximum wind.


2021 ◽  
Author(s):  
Yi-Da Xu ◽  
Ming-Deng Yuan ◽  
Ruijiang Wang

Parainvolucrella R.J. Wang, a new monotypic genus is segregated from Hedyotis-Oldenlandia complex based on the morphological and molecular evidences, along with the new combination of P. scabra (Wall. ex Kurz) M.D.Yuan & R.J.Wang. The new genus is phylogenetically sister to Scleromitrion and has ever been mistaken as a member of Scleromitrion, but its perennial woody herbaceous habit, terminal inflorescence, heterostylous flowers, indehiscent capsules, and microreticulate with smooth muri pollen surface ornamentation make it different from the latter. A key for all the genera of this complex in China is provided as well.


2020 ◽  
pp. 1-42
Author(s):  
Alla Hayrapetyan ◽  
Angela A. Bruch

The palynomorphology of 19 modern species of the genus Quercus L. native to Armenia and adjacent regions, including the Caucasus and Transcaucasia, the Mediterranean region (especially Turkey), as well as Iran, Iraq and Afghanistan, was studied using light microscopy (LM) and scanning electron microscopy (SEM). The work revealed two main types of apertures (3-zonocolpate, 3-zonocolp-porate) as well as six morphological types of pollen based on three main types of exine ornamentation (tuberculate, verrucate, rugulate). We suggest that two main groups of exine ornamentation developed from a common initial type. The first group covers all species of the subgenus Quercus and also Q. suber and Q. alnifolia of the subgenus Heterobalanus. The second group is limited to the morphological type Q. ilex (species Q. ilex, Q. coccifera, subgenus Heterobalanus). On the other hand, the presence of widespread interspecific and introgressive hybridization within the genus Quercus indicates an ongoing process of speciation. This also has an effect on pollen features, which are very similar in a number of species but also vary in individual samples even within the same species. The morphological uniformity of the pollen surface (especially for the subgenus Quercus), the presence of islets of secondary sporopollenin on the surface of pollen grains, as well as orbicules in anthers, do not indicate general primitiveness of representatives of this genus but most likely denote a relatively high degree of speciation activity within this group.


2019 ◽  
Vol 50 (4) ◽  
Author(s):  
Sadeq & Aliwy

Seven plants species that belong to Asteraceae (Compositae) family have been investigated micro-morphology with the help of scanning electron microscopy (SEM) observations. Plants were collected from University of Baghdad campus during January to May in 2017-2018 and the species are: Calendula persica C. M. May, Carduus pycnocephalus L., Erigeron canadensis L., Lactuca serriola L., Silybum marianum  (L.) Garth, Sonchus oleraceus L., Urospermum picroides (L.) Schmidt. The aim of this study was to describing the external morphology of seeds as well as a detailed study of pollen grains morphology. Special emphasis is given to the size, shape, polar and equatorial length, spines length, length and width of ora and colpi, tectum sclupturing, and the ornamentations on pollen surface, Sonchus oleraceus and Lactuca serriola pollen grains have a special exin sculpture, which is lophate and the other species used in this study is non-lophate, and all the pollen grains of the species used in this study are tri-zono- colporate, Calendula persica is only species that it is exin sculpture is echinate with spines length (3.8-4.3 um), and the exin sculpture of the other species is spinulose. Also special importance is given to the size, shape, pappus, beak length, primary and secondary sculpturing, carpopodium, as well as the surface of the seed (Cypsela), Seeds (cypsela) of the species used in this study were significantly different in morphology, The shapes of the 7 species were differed in each species and it showed 7 different shapes: narrowly-oblong, oblong, long-oblong, board-oblong, widely curved-oblong, narrowly-ellipitic, and narrowly-obovated.


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