scholarly journals Pollen characters as taxonomic evidence in some species of Dipsacaceae from Iran

2017 ◽  
Vol 24 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Ebadi-Nahari Mostafa ◽  
Nikzat-Siahkolaee Sedigheh ◽  
Eftekharian Rosa

Pollen morphology of nine species representing four genera: Cephalaria Schrad, Dipsacus L., Pterocephalus Vaill. and Scabiosa L. of the family Dipsacaceae in Iran has been investigated by means of scanning electron microscopy (SEM). The results showed that pollen grains were triporate and tricolpate. The pollen type of Scabiosa rotata Bieb. (tri- and tetraporate) is the first report in the world. The sizes of pollen grains fall into the classification group magna (pollen grain diameter 50–100 μm). Pollen shapes vary from preoblate to prolate and their polar views were triangulate and lobate. The exine ornamentation varies from gemmate in S. rotata to spinulate in the rest studied species. Species of Scabiosa have been dispersed in UPGMA tree that this confirmed the previous studies about taxonomic problems and species complexity in this genus. These results show the transfer of the some Scabisoa species to Lomelosia Raf. based on palynological characters. Pollen morphology of the family is helpful at the generic and specific level.Bangladesh J. Plant Taxon. 24(2): 129–136, 2017 (December)

Author(s):  
Mehdi Heidarian ◽  
Seyed Mohammad Mehdi Hamdi ◽  
Mohammad Mehdi Dehshiri ◽  
Taher Nejadsattari ◽  
Seyed Mohammad Masoumi

Aims: The aim of this research was to investigate the morphological characteristics of the pollen grain of some species of genus Allium. Methodology: The pollen grains were examined by using Light Microscopy (LM), Scanning Electron Microscopy (SEM) and the pollen grains of one species under Transmission Electron Microscopy (TEM). Results: The pollen grains were oblate and medium in shape and size. The pollen ornamentation of exine surface, exine ornamentation on sulcus edge, lumina number in the exine surface and the state of pollen grain apex in the examined species were different. Semitectate and columellate ectexine with discontinuous endexine were seen in the pollen wall structure (sporoderm). The dendrogram obtained from the pollen characters in SEM observations by using the numerical taxonomy system (NTSYS) software placed the studied species in two types. Conclusion: Our palynological dendrogram can be used for segregation the sections and subgenera taxonomical levels in the studied species of genus Allium and confirmed the phylogram of the recent phylogenetic research.


2015 ◽  
Vol 22 (2) ◽  
pp. 99-110 ◽  
Author(s):  
Maryam Naderifar ◽  
Ali Sonboli ◽  
Abbas Gholipour

Pollen morphology of 11 Iranian Dracocephalum L. species was investigated using light and scanning electron microscopy to evaluate their taxonomic significance for the infrageneric classification of the genus. Pollen grains of all examined taxa were isopolar, hexacolpate, circular in polar view and spheroidal to prolate in equatorial view (P/E = 1.0?2.0). The smallest pollen grains were observed in D. aucheri (P = 29.7 ?m, E = 22.6 ?m), while the largest pollen was found in D. lindbergii (P = 45.1 ?m, E = 33.7 ?m). The highest and lowest apocolpium index (AI) were measured in D. aucheri (AI = 0.27) and D. surmandinum (AI = 0.08), respectively. Colpus membrane was egranulate in all examined species except for D. multicaule and D. ghahremanii. The main exine ornamentation type was characterized as bireticulate including five different subtypes. The results revealed that the exine ornamentation is a diagnostic character useful for the classification of Dracocephalum.Bangladesh J. Plant Taxon. 22(2): 99-110, 2015 (December)


Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 849-856 ◽  
Author(s):  
M. L. Frean

Pollen grains of the Euphorbiaceae show a number of pollen types which can be clearly distinguished. Generally different genera are characterized by a specific pollen type.  Euphorbia obesa Hook. f. and Croton gratissimus Burch, subsp.  subgratissimus (Prain) Burtt Davy, represent two genera within the Crotonoideae with different morphology, each type characteristic for the respective genus. Taxonomically, the genus Euphorbia with apetalous flowers consisting of a naked pistil surrounded by several staminate flowers within a cyathium, is considered more advanced than the genus  Croton. In  Croton the inflorescence is a raceme with unisexual flowers. The floral whorls of the male show numerous anthers and both calyx and a showy corolla are present. Both genera are insect pollinated. In both  Euphorbia obesa and  Croton gratissimus the pollen wall in section shows columellae, a structure characteristic of angiosperms. However the present ontogenetic studies show that the formation of the columellae differs entirely in the two pollen types. The final stratification of the wall as well as the morphology of the grains differ and evaluation of the exine structure indicates that phylogenetically Croton pollen shows more advanced characters than  Euphorbia — contradicting the floral phylogeny. This study conducted at light and electron microscope level compares the two pollen types morphologically and ontogenetically, concentrating mainly on the formation of the exine which is tectate-perforate in the prolate tricolpate grain of Euphorbia obesa and semi-tectate in the anaperturate, spheroidal grain of Croton gratissimus. The aim of the study was to evaluate the significance of pollen characters in taxonomic and phylogenetic relationships within the Euphorbiaceae. The differing pollen morphology which is related to the taxonomic grouping of tribes within the subfamily (Crotonoideae) emphasizes diversity, which may result from physiological adaptation. The study shows that the same functional end may well be achieved in different ways and this may be a factor underlying the diversity in the heterogeneous family Euphorbiaceae.


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.


2012 ◽  
Vol 81 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Parisa Panahi ◽  
Mohammad R. Pourmajidian ◽  
Asghar Fallah ◽  
Mehdi Pourhashemi

For the first time, pollen morphology of 9 (4 spp. and 5 subspp.) taxa representing lobed leaved oaks of Iran in the family of Fagaceae has been examined and illustrated using light microscopy and scanning electron microscopy of acetolysed material. Detailed pollen morphological characteristics are given for <em>Quercus</em> section. The pollen grains are single, isopolar, radially symmetrical, tricolpate, tricolporoidate or tricolporate. Pollens were studied to show all possible characteristics like shape, size, apertures, wall thickness, etc., with special reference to the specific features of each pollen type such as structural, sculptural and suprasculptural patterns. There is considerable variation in pollen morphology between taxa so that, three types of pollen shape, five types of structural pattern, two types of sculptural pattern, five types of suprasculptural pattern and three types of perfora distribution are defined. Furthermore, the relationship between pollen morphology and taxonomy is discussed. Overall, pollen characters are shown to be a useful and informative tool for assessing taxonomic position within <em>Quercus</em> section in Iran.


PhytoKeys ◽  
2019 ◽  
Vol 128 ◽  
pp. 121-140 ◽  
Author(s):  
Catalina Ruiz-Domínguez ◽  
Andrew P. Vovides ◽  
Victoria Sosa

Hylocereeae is one of the nine tribes in the subfamily Cactoideae (Cactaceae), for which the limits and recognition of genera have been controversial. Essentially, this group comprises epiphytic and hemiepiphytic genera with stems modified as climbing structures. The aim of this paper is to examine pollen attributes in representative species of genera of Hylocereeae, focusing on Selenicereus whose current circumscription comprises Hylocereus and three Weberocereus species, to find whether significant potentially apomorphic and/or autapomorphic systematic characters can be discovered. Utilizing SEM and light microscopy, 25 pollen characters were observed and measured. Tribe Hylocereeae is stenopalynous, with pollen grains isopolar and radially symmetrical monads, mostly tricolpate, except in Kimnachia, Pseudoripsalis and Weberocereus, whose pollen grains are pantocolpate. Seven attributes (five qualitative and two continuous) exhibited useful variation and were coded. The character of brevicolpate pollen grains was shared by Kimnachia ramulosa and Pseudorhipsalis amazonica. Convex quadrangular outline in the polar view was shared by Weberocereus tunilla and S. glaber. The absence of spinules on the exine was shared by S. minutiflorus and S. stenopterus. The largest pollen grain, found in Selenicereus megalanthus, might be correlated with polyploidy. Selenicereus is the taxon with the highest variation in pollen attributes, including species with an exine with or without spinules and variable polar area index and shape (subprolate or oblate-spheroidal).


2019 ◽  
Vol 7 (3) ◽  
pp. 354-358
Author(s):  
Pushpa Karna Mallick

Pollen morphology of twelve species of angiosperms from Central Nepal was cytologically carried out in present investigation. In this investigation pollen morphology of Bignonia venusta Ker Gawl. and Jacranda mimisifolia D.Don from the family Bignoniaceae; Brassica compestris L. from Brassicaceae; Cuphea hyssopifolia Kunth. from Lythraceae; Coriandrum sativum L. from Apiaceae; Crepis japonica L. and Dichrocephala integrifolia (L f.) kunzte. from Asteraceae; Delphinium ajacis L. from Ranunculaceae; Dianthus barbetus L. from Caryophyllaceae; Euphorbia Milii Des Moul. and Euphorbia pulcherima L. from Euphorbiaceae and Magnolia fuscata from Magnoliaceae were studied. Shape of the pollen grains found to be mostly spheroidal, few circular, one elliptical, one triangular and one elongated in this study. Sculpture of exine wall found to be smooth, echidnae, tected, reticulated and perforated type. Aperture of the pollen grains found to be triporate to pentaporate. The large, medium and small sized pollen grains were observed in present research. The high diversty of sculpture type in pollen grains of angiosperms has been associated to diversity in pollination systems. Smooth pollen grains are linked with wind or water pollination while sculptured pollen grains associated with biotic pollination. The morphology of pollen grain is one of the significant tools in solving some taxonomic problems such as identification, tracing phylogenetic relationship on the family, generic or specific level and in plant systematic and evolution. Int. J. Appl. Sci. Biotechnol. Vol 7(3): 354-358


1970 ◽  
Vol 16 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Hülya Özler ◽  
Evren Cabi ◽  
Ebru Us ◽  
Musa Do?an ◽  
Sevil Pehlivan

Pollen morphology of Agropyron cristatum (L.) Gaertner. s.s. (subsp. incanum (Náb?lek) Melderis and subsp. pectinatum (M. Bieb.) Tzvelev, latter including var. pectinatum and var. imbricatum (Roemer & Schultes) G. Beck) in Turkey has been studied by using light microscope and scanning electron microscope. The above-mentioned taxa are homogenous in both aperture type and exine ornamentation. Pollen grains are monoporate (rarely diporate in the case of var. imbricatum) having scabrate grouped exine surface. The scabra density and the height of scabrae as well as other morphological parameters such as annulus and operculum diameter are peculiar features for differentiation of taxa. Two different phenograms were created with the UPGMA (Unweighted Pair Group Method with Arithmetic mean) clustering technique using quantitative measurements of the pollen grains.   Keywords: Agropyron; Pollen morphology; SEM; Turkey.DOI: 10.3329/bjpt.v16i1.2743Bangladesh J. Plant Taxon. 16(1): 21-28, 2009 (June)


1981 ◽  
Vol 29 (2) ◽  
pp. 159 ◽  
Author(s):  
PA Gadek ◽  
HA Martin

The pollen morphology of 28 species from the subtribe Metrosiderinae (s.Bentham) is described and compared in the light of several recent taxonomic revisions of this subtribe. All species have the same basic Myrtaceous pollen type, but there is intra and interspecific variability seen in a number of the pollen characters. Intraspecific variability is related either to changes in volume and size of the pollen grain or to the occurrence of polar islands. It is concluded that the character of syncolpy or parasyncolpy as relating to the presence or absence of polar islands may not be taxonomically reliable at the species level. Interspecific variation. and thus those characters most useful in assessing the taxonomy, relate to the structure of the angle of the amb, the exine structure and sculpture and the definition, form and type of colpi and apocolpia. One species shows a difference in polarity from the rest. Three basic exine sculpture types were defined, but it was necessary to examine them under the scanning electron microscope (SEM) because their patterns could not be resolved under the light microscope. Acetolysis enhanced the definition of the smaller basic sculptures under the SEM. Generally, the pollen morphology of these species was found to support the recent taxonomic revisions of this subtribe.


2008 ◽  
pp. 60-71 ◽  
Author(s):  
Suparna Gupta ◽  
Arunima Ghosh ◽  
Subrata Maity ◽  
Sauren Das

A study on pollen morphology of four common Indian mangroves from Sundarbans mangrove swamps, three species from the family Rhizophoraceae (Bruguiera sexangula Laur., Ceriops tagal Perr.and Rhizophora mucronata Lamk.) and one species from the family Avicenniaceae (Avicennia marina Forsk.) was carried out. Shape of the pollen grains were prolate, prolate spheroidal and subprolate with tricolporate apertures. Surface ornamentation of the studied taxa was reticulate, finely reticulate or scabrate. Pollen grain viability of the said taxa was determined by stain test (1% aceto-orcein) under in situ condition and percentage of viable pollen production was recorded. The result revealed that all the studied taxa produce a fairly good amount of viable pollen grains in natural condition, an indication that they are good propagule producer in the long run. Pollen grain germination and measurements of pollen tube length using different sucrose concentrations (0.2, 0.6, 1.0, 1.2, 1.6 and 2.0%). Maximum pollen fertility and pollen tube length occurred in 2% sucrose solution in case of A. marina and B. sexangula, whereas 1.6% in C. tagal and 1.0% in R. mucronata. A strong positive correlation exist between pollen germination and pollen tube length, but there was a hardly relation between sucrose concentration and pollen tube length.


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