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

2013 ◽  
Vol 85 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Saulo M. Sousa ◽  
Patrícia M.O. Pierre ◽  
Giovana A. Torres ◽  
Lisete C. Davide ◽  
Lyderson F. Viccini

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.

2012 ◽  
Vol 26 (4) ◽  
pp. 916-923 ◽  
Author(s):  
Marcos Gonçalves Ferreira ◽  
Maria Lúcia Absy ◽  
Vânia Gonçalves-Esteves

A pollen morphology study of the Gentianaceae Juss. of Reserva Florestal Adolpho Ducke (Manaus, Brazil) was performed. The pollen grains of the studied species varied morphologically in their pollen units (tetrads or monads), size (small, medium and large), shape (oblate, suboblate, oblate spheroidal, spheroidal, prolate spheroidal and prolate), polarity (heteropolar, isopolar or subisopolar), symmetry (bilateral or radial) and number and type of aperture (3-colporate and 1-3porate). In relation to ornamentation, pollen grains had a sexine that was psilate in the Voyria species, microreticulate in Voyriella parviflora and reticulate heterobrochate in Tachia grandiflora and Irlbachia alata. The exine in I. alata showed great variability in the size and shape of the lumina, in addition to clavae of various sizes in the mesocolpium and apocolpium areas. In Tachia grandiflora, besides to long colpi, the heterobrochate exine demonstrated an increase in the lumina in the mesocolpium areas that decreased considerably in the apocolpium areas. In the species of Voyria, the pollen grains showed differences in shape, polarity and the number of apertures, which were spherical, isopolar and 3-porate in Voyria spruceana; prolate/oval, heteropolar and 1-porate in Voyria tenella; and oblate/elliptical (reniform), heteropolar and 2(3)-porate in Voyria aphylla and Voyria caerulea. The variations in pollen morphology and the peculiar characteristics of the genus suggest that Voyria should be treated as a unique taxon within Gentianaceae.


2012 ◽  
Vol 26 (1) ◽  
pp. 46-57 ◽  
Author(s):  
BenoÎt Loeuille ◽  
Raquel Maria Batista Souza-Souza ◽  
Vanessa Holanda Righetti Abreu ◽  
Cláudia Barbieri Ferreira Mendonça ◽  
Vania Gonçalves-Esteves

In order to evaluate the significance of the pollen morphology for generic and infrageneric taxonomy of the genus Eremanthus (Vernonieae, Asteraceae), and to provide additional data for its phylogenetic reconstruction, the pollen of 20 of the 23 species of the genus was examined using light and scanning electron microscopy. Acetolysed pollen grains were measured, described, and illustrated using light microscopy, while non-acetolysed pollen grains were analyzed using scanning electron microscopy. Pollen grains of these species are isopolar, oblate-spheroidal in most of the species, more rarely prolate spheroidal or suboblate, subtriangular amb, tricolporate and subechinolophate. The variation among quantitative characters does not correlate with the macromorphological subdivision of the genus or with the generic or specific limits.


2014 ◽  
Vol 21 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Muazaz Al-Hadeethy ◽  
Athiya Al-Mashhadani ◽  
Talib Al-Khesraji ◽  
Sahapat Barusrux ◽  
Hazim Al-Jewari ◽  
...  

The present study highlights the taxonomic values of the pollen features of 20 species of Verbascum L. in Iraq. The pollen grains were acetolysed and observed under Light and Electron microscopes. Our results showed that the pollen grains of these species are usually radially symmetrical, isopolar, tricolporate and display reticulate sculpturing. The variations were found in shape, size, and exine thickness. Most of the species are subprolate, prolate spheroidal, and prolate, whereas oblate spheroidal pollens were found only in V. thapsus. The pollen size among the species studied ranges from 16.2-32.5 µm. The majority of species are medium sized except V. agrimoniifolium and V. oreophilum that are small sized, and four species i.e. V. palmyrense, V. sinuatum, V. songaricum, and V. thapsus having both small and medium sized pollen grains. Moreover, the result showed that the exine thickness ranges from 0.87-4.75 µm, but this value can overlap between some species. Therefore, only the shape of pollen grains could be used to classify these species into groups.DOI: http://dx.doi.org/10.3329/bjpt.v21i2.21355Bangladesh J. Plant Taxon. 21(2): 159-165, 2014 (December)


Author(s):  
Kadry Abdel khalik ◽  
Suad Al- Ruzayza ◽  
Abdullah Assiri ◽  
Ahmed Elkordy

Pollen morphology of 20 species belong to seven genera (Abutilon, Althaea, Hibiscus, Malva, Pavonia, Senra and Sida) of Malvaceae from Saudi Arabia were studied by using light microscope (LM) and scanning electron microscope (SEM). Quantitative and qualitative pollen morphological characters which vary among investigated taxa are found in the pollen polarity, symmetry, size, shape, polar axis, equatorial diameter, P/E ratio, average height and width of spine, aperature character and spine index. The pollen grains vary from spheroidal, prolate spheroidal, oblate spheroidal to suboblate. All taxa were characterized by relatively large to medium sized pollen grains, numerous pores scattered irregularly all over the grain, and echinate sculpturing. Sida ovata is the largest size pollen grain (138.95) µm. On the other hand, Malva parviflora showed the smallest pollen size (52.28 µm). The average height and width of spine varied greatly among studied taxa. The highest spines (20.65µm) found in Sida ovata, while the shortest (3.19 µm) was found in Abutilon pannosum. Results of the pollen shape, size, and exine sculpture characters offered useful data for evaluating the taxonomy of Malvaceae both on subgeneric and sectional levels. A key for the identification of the investigated taxa based on pollen grains characters is also provided


Phytotaxa ◽  
2019 ◽  
Vol 404 (5) ◽  
pp. 171
Author(s):  
MITRA LAL PATHAK ◽  
MUHAMMAD IDREES ◽  
BO XU ◽  
XIN FEN GAO

Pollen morphology of 27 species of Photinia sensu stricto and five closely related genera of subfamily Maloideae (Rosaceae) were studied in detail. Palynomorphological characteristics were examined using scanning electron microscopy (SEM). Comparative pollen analysis was accomplished based on pollen size, shape, polar and equatorial views, polar and equatorial diameter ratio (P/E ratio), width of aperture, and exine ornamentation. The pollen grains of studied species were found to be monad, tricolporate, small to medium in size (P=17.42–30.45 μm, E=9.26–20.18 μm) and to have shapes oblate-spheroidal (0.88–1.0 μm), prolate-spheroidal (1.01–1.14 μm), sub-prolate (1.15–1.33 μm), prolate (1.34–2 μm), and perprolate (>2 μm). The exine ornamentation was perforated-striate, and two different types were identified. The result of quantitative characters has paltry taxonomic importance. The characters studied here delimit at generic level for some genera but not at species level. The obtained result was partially consistent with that of molecular studies published earlier. The pollen size and shape were found to be different between Asian and American species of Photinia. Especially exine sculpture was found to be an important feature to distinguish species of all genera studied. PCA analysis showed that the pollen shape, pollen sculpture, pollen size, and polarity are the key characters to distinguish the species of Photinia and the closely related genera in subfamily Maloideae. Based on pollen exine, two groups (Type I and Type II) were distinguished. The aim of the present study was to find out the taxonomic significance of palynomorphological characteristics in subfamily Maloideae (Rosaceae).


Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Alano César Rocha de Assis ◽  
Eduardo Custódio Gasparino ◽  
Marileide Dias Saba

Abstract In the present work, the pollen morphology of 22 species of Anacardiaceae was analysed, occurring in the state of Bahia, Brazil. The palynological material was obtained from specimens deposited in herbaria. The pollen grains were acetolysed, measured, illustrated and described under light and scanning electron microscopies. The quantitative data were statistically analysed according to sample size. The analysed species presented pollen grains in monads, small to medium sized, isopolar, amb circular to subtriangular, with shapes varying from oblate-spheroidal to prolate, 3-colporate, with fastigium in some species. The exine ornamentation was characterized as psilate, striate, microreticulate-striate, striato-perforate, suprastriato-infra(micro)reticulate. The pollen morphology variation confirms the eurypalynous character of the family. The attributes of the apertures and exine may collaborate in the taxonomic circumscription and provide a clarification of the phylogenetic relationships of the group.


Phytotaxa ◽  
2018 ◽  
Vol 333 (2) ◽  
pp. 209 ◽  
Author(s):  
AYŞE ÖZTÜRK ◽  
KUDRET BETÜL GÜNEY ◽  
BARIŞ BANİ ◽  
KERİM GÜNEY ◽  
FAİK AHMET KARAVELİOĞULLARI ◽  
...  

Pollen morphology of six Verbascum (Scrophulariaceae) taxa belonging to five different groups in the genus [V. georgicum (group E), V. nudatum var. nudatum (group F), V. cariense (group F), V. bithynicum (group H), V. pycnostachyum (group K), and V. lasianthum (group L)] was studied. Pollen slides were prepared according to the Woodhouse method and were examined with light-microscopy (LM) and Scanning Electron Microscopy (SEM). All studied pollen grains are generally monads, though tetrads (5 %) were observed in Verbascum nudatum var. nudatum. Pollen grains of all studied taxa were determined as isopolar and radially symmetric. In general terms, aperture types are trizonocolporate, but also trisyncolpate (V. lasianthum 10 %, V. pycnostachum 1 %, and V. georgicum 4 %) and trizonocolpate (V. cariense 10 %, V. bithynicum 10%, V. lasianthum 90%, V. pycnostachyum 9%, and V. georgicum 96 %) aperture types were observed. The shapes of the pollen grains were determined as prolate, subprolate, prolate-spheroidal and oblate-spheroidal. The sculpture was reticulate in all cases. The results of the study corroborate that morphological features, such as pollen shape, polar axis length (P), equatorial axis length (L), aperture type, surface ornamentation, muri thickness, and lumina shape, show differences which can be taken into consideration in the systematic discrimination within the groups, and also for discrimination of the groups in the genus.


2020 ◽  
Vol 8 (4) ◽  
pp. 131-138
Author(s):  
Rizgar Y. Ismail ◽  
Saleem E. Shahbaz

The polleniferous material of Centaurea taxa grow in Kurdistan-Iraq was collected. Samples were tested using scanning electron microscopy (SEM) and light microscopy (LM). In the polar view, pollen grain outlines are mostly triangular or triangular-circular. In equatorial view, the elliptic shape is common, while circulars or semicircular shapes are rare. The exine sculpture is scabrate, and the tectum is perforate. Number of sculpture microspinules/ µm², and their heights together with the number of wall perforations provide significant characters for taxa delimitation. Pollen grains of all species are of medium size, very few of some species pollen are larger or smaller in size. Species producing subprolate pollen shape is common, while oblate spheroidal and Prolate spheroidal shapes are less common. The principal component analysis and the discriminant analysis can recognize 65.478% and 87.54% of the total variability respectively; moreover, the discriminant function can correctly classify 125 or 78.125% out of 160 observations for pollen traits. 


2020 ◽  
Vol 51 (2) ◽  
pp. 565-573
Author(s):  
Al-Dobaissi & et al.

This research was aimed to study the pollen morphology for the genus Pterocephalus(Vaill)  from Dipsacaceae family in Iraq, and to utilize these feathers in isolating the species as valuable taxonomic traits for enriching Iraqi flora. The study included characteristics of the type, shape, size, sculpturing and apertures, as well as determining the full dimensions using light microscopy as well as numerical analysis of this species and draw polygonal shapes and denderogram  convergence between species. The results of the study of pollen and polygonal forms showed significant differences in the characteristics at the level of each species, which helps to identification the genus species, as it was found that the pollen was a tricolpate, and shape was specified to be sub spheroidal,  sub prolate, oblate spheroidal. and prolate spheroidal, The pollen grains varied in size between large,  and very large size. However the most significant feature is that included four types of sculpture using to isolate the species to  : Reticulate and spinate in P. laxus ,P. strictus, and P. nestorianu, reticulate and spinulate in P. brevis, P. plumosus, Reticulate to striate and spinulate in P. canus, and Spinate in  P. kurdicus, and  P. pyrethrifolius. The dendritic scheme showed the convergence of some species among them and in varying convergence ratios.            


2014 ◽  
Vol 73 (1) ◽  
pp. 90-103 ◽  
Author(s):  
Shahryar Saeidi Mehrvarz ◽  
Narjes Yousefi ◽  
Maryam Mohammadi ◽  
Thomas Marcussen

AbstractPollen morphology of 17 species of Viola representing five sections, Melanium, Plagiostigma, 'Spathulidium' ined., Sclerosium, and Viola, was studied using light and scanning electron microscope. Pollen grains were usually symmetrical, tetrazonocolporate to pentazonocolporate in section Melanium and trizonocolporate to tetrazonocolporate in the other four sections. Pollen shape was circular to subtriangular, tetragonal or pentagonal in polar view and prolate to oblate, spheroidal or pyramidal in equatorial view. Exine ornamentation was granulate, psilate and mostly perforate. The psilate type was only observed in V. modesta.We found heteromorphy in aperture number in V. caspia of section Viola, V. occulta of section Melanium and V. behboudiana of section Sclerosium, which corroborates their higher ploidy than in related species (octoploid versus tetraploid).


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