A study on the pollen morphology of the genus Combretum Loefl. and its taxonomic significance

Pollen grains of 92 species (from 99 collections) belonging to the genus Com-bretum (Combretaceae) were examined by Light Microscope (LM) and Scan-ning Electron Microscope (SEM). These species are representatives of vari-ous taxa outlined in the latest taxonomic revision of the genus. The genus belongs to a tropical or subtropical family, frequently encountered in various Quaternary deposits and acts as ecological indicator in various habitats. Pol-len grains of all members of the genus Combretum examined are hetero-colpate (with three simple apertures alternating with three composite ones) and exhibited wide range of inter-specific variation with respect to polar axes (P), Equatorial diameters (E), P/E ratios, shape classes, shape in polar view, costae pori, vestibula, protrusion of endoapertures and exine sculptur-ings. Species delimitation in these nine characters is tabulated. Four shape classes, eight exine sculpturings and seven pollen types were recognized. A key for identification to these pollen types is presented and the species in-cluded in each of these types are also outlined. Previous macro-morphological and molecular classification of the genus were discussed in the light of the present palynological study.

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Pollen morphology of Iranian Dracocephalum L. (Lamiaceae) and its taxonomic significance

Bangladesh Journal of Plant Taxonomy ◽

10.3329/bjpt.v22i2.26071 ◽

2015 ◽

Vol 22 (2) ◽

pp. 99-110 ◽

Cited By ~ 3

Author(s):

Maryam Naderifar ◽

Ali Sonboli ◽

Abbas Gholipour

Keyword(s):

Electron Microscopy ◽

Pollen Morphology ◽

Pollen Grains ◽

Polar View ◽

Taxonomic Significance ◽

Infrageneric Classification ◽

Exine Ornamentation ◽

Plant Taxon ◽

Scanning Electron

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)

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Pollen morphological traits analysis of eighteen 'Nepeta' species in Iran

Mediterranean Botany ◽

10.5209/mbot.62919 ◽

2020 ◽

Vol 41 (1) ◽

pp. 85-99

Author(s):

Seyed Mehdi Ttalebi ◽

Majid Ghorbani Nahooji ◽

Mahbobeh Yarmohammadi ◽

Narjes Azizi

Keyword(s):

Pollen Grains ◽

Polar View ◽

Morphological Characters ◽

Pca Analysis ◽

Prolate Spheroidal ◽

Qualitative And Quantitative ◽

Exine Sculpturing ◽

Identification Of Species ◽

Sectional Classification

Nepeta is one of the largest genera of Lamiaceae, which is widely distributed in Iran. Several species of the genus are traditionally used as culinary, industrial, and medicinal plants. In the present study, we examined fourteen qualitative and quantitative pollen morphological characters of twenty-four populations of eighteen Nepeta using light and scanning electron microscope. The pollen grains are radially symmetric, isopolar, and hexacolpate in all species. We have found that the quantitative features vary among the studied taxa. According to PCA analysis, the colpus length and width are the most variable traits. Polar view shapes in all the studied taxa are circular, while the equatorial view is prolate-spheroidal, subprolate, perprolate, and prolate. We determined microreticulate and bireticulate exine sculpturing, and the bireticulate type was dominant. We revealed that polar and equatorial axes length of pollen grains varied between populations of the same species, and they, therefore, should be ignored in taxonomical identification of species. The polar view was similar in all the studied pollen grains and could not be considered as a diagnostic trait. The equatorial shape was stable between populations of the same species, and this was taxonomically important, while we registered some infraspecific variations in exine sculpture. Our cluster of taxa based on the pollen morphology is not in concordance with the traditional sectional classification of the genus.

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Palynological characterization and genetic divergence between accessions of chilli and sweet peppers

Horticultura Brasileira ◽

10.1590/s0102-05362013000400010 ◽

2013 ◽

Vol 31 (4) ◽

pp. 568-573 ◽

Cited By ~ 3

Author(s):

Kellen C Martins ◽

Sérgio Alessandro M Souza ◽

Telma Nair S Pereira ◽

Rosana Rodrigues ◽

Messias G Pereira ◽

...

Keyword(s):

Genetic Divergence ◽

Pollen Grains ◽

Principal Component ◽

Polar View ◽

Polar Axis ◽

Area Index ◽

Front View ◽

Capsicum Spp ◽

Polar Area

This study characterised pollen grains morphologically and studied the genetic divergence between accessions based on morphopollinic characters. Seven accessions, including domesticated, semi-domesticated and wild species of Capsicum (C. annuum var. annuum, C. chinense, C. baccatum var. pendulum, C. frutescens, Capsicum annuum var. glabriusculum, C. baccatum var. baccatum and C. parvifolium), were cultivated in a greenhouse and their pollen grains collected and fixed during flowering. The pollen grains were acetolysed and described based on 13 pollinic characteristics (polar and equatorial axes, in an equatorial front view; ratio between polar axis and equatorial axis; equatorial axis in a polar view; thicknesses of the exine, sexine and nexine; apocolpus side; polar area index; length and diameter of the pore and colpus). The genetic divergence analysis between the accessions was based on the standardised average Euclidean distance, and the grouping analysis was based on Ward's method. PCA (principal component analysis) is another multivariate method that was used. Based on Ward's method and PCA, it was possible to group the accessions into two groups, and the groups formed correlated with the classification of the gene pool complexes already described for the genus. According to this classification, the Capsicum genus comprises three major groups: C. annuum, C. chinense and C. frutescens form the annuum complex; C. baccatum and C. pratermissum form the baccatum complex; and C. eximium, C. cardenasii and C. pubescens form the pubescens complex. The variable width of the pores was the most discriminating in this morphopollinic study of Capsicum spp.

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Embryology of Veratrum and its systematic significance

Phytotaxa ◽

10.11646/phytotaxa.437.4.3 ◽

2020 ◽

Vol 437 (4) ◽

pp. 213-226

Author(s):

SI-MIN REN ◽

CHUN-HAI ZHAO ◽

YUN-YUN ZHAO ◽

JIA-XI LIU

Keyword(s):

Female Gametophyte ◽

Pollen Grains ◽

Polar View ◽

Systematic Position ◽

Wall Structure ◽

Anther Wall ◽

Surface Ornamentation ◽

First Time

The systematic position of Veratrum has been controversial for many years. The purpose of the present research is to study embryological features and the systematic position of Veratrum in detail. Microsporogenesis, megasporogenesis, development of male and female gametophyte and changes of anther wall structure during pollen development of V. grandiflorum and V. nigrum were studied using conventional paraffin sectioning technique and light microscopy for the first time, and pollen morphology of V. grandiflorum with scanning electron microscopy was investigated. The results showed that 1) cytokinesis of both V. grandiflorum and V. nigrum microsporocytes is of the successive type; 2) microspore tetrads are either tetragonal or tetrahedral; 3) mature pollen grains are two-celled with wide-elliptic morphology, round ends at the polar view, a monosulcate colpus and reticulate surface ornamentation; 4) ovaries have axile placenta with three locules, each of which has multiple campylotropous, bitegmic, crassinucellate ovules with micropyle formed by the inner integument; and 5) their female gametophyte is of the Allium-type. Overall, these results support classification of Veratrum in Melanthiaceae (Liliales).

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Contribution to the knowledge of the pollen morphology of the genus Salvia (Lamiaceae)

Phytotaxa ◽

10.11646/phytotaxa.428.3.4 ◽

2020 ◽

Vol 428 (3) ◽

pp. 228-240

Author(s):

HÜLYA ÖZLER ◽

AHMET KAHRAMAN ◽

SEVİL PEHLİVAN ◽

MUSA DOĞAN ◽

BİROL BAŞER ◽

...

Keyword(s):

Pollen Morphology ◽

Pollen Grains ◽

Polar View ◽

Pollen Data ◽

Infrageneric Classification ◽

Oblate Spheroidal ◽

Pollen Characters ◽

Exine Sculpturing ◽

First Time

The pollen grains of 19 Turkish Salvia species in Aethiopis, Drymosphace, Hemisphace, Hymenosphace and Salvia sections, 13 of which are endemic to Turkey, were investigated, documented and illustrated through Light Microscopy (LM) and Scanning Electron Microscopy (SEM). This study provides pollen data of 14 species for the first time. The pollen grains of the species examined are monads, isopolar, radially symmetrical and hexacolpate, mostly medium in size, slightly elliptic to more or less circular in polar view and mainly oblate-spheroidal in equatorial view. Two different ornamentation types are recognized on exine sculpturing; reticulate-perforate and bireticulate. The present results do not generally support the traditional infrageneric classification of Salvia, but provide useful pollen characters for species delimitation.

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Precise automatic classification of 46 different pollen types with convolutional neural networks

10.1101/2020.02.14.949149 ◽

2020 ◽

Author(s):

Víctor Sevillano ◽

Katherine Holt ◽

José L. Aznarte

Keyword(s):

Neural Networks ◽

Deep Learning ◽

Pollen Grains ◽

Correct Classification ◽

Visual Classification ◽

Learning Techniques ◽

Pollen Types ◽

Human Operators ◽

Manual Classification

AbstractIn palynology, the visual classification of pollen grains from different species is a hard task which is usually tackled by human operators using microscopes. Many industries, including medical and farmaceutical, rely on the accuracy of this manual classification process, which is reported to be around 67%. In this paper, we propose a new method to automatically classify pollen grains using deep learning techniques that improve the correct classification rates in images not previously seen by the models. Our proposal manages to properly classify up to 98% of the examples from a dataset with 46 different classes of pollen grains, produced by the Classifynder classification system. This is an unprecedented result which surpasses all previous attempts both in accuracy and number and difficulty of taxa under consideration, which include types previously considered as indistinguishable.

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Palynological study of some Iranian species of Scabiosa L. (Caprifoliaceae)

Bangladesh Journal of Plant Taxonomy ◽

10.3329/bjpt.v23i2.30855 ◽

2016 ◽

Vol 23 (2) ◽

pp. 215-222 ◽

Cited By ~ 2

Author(s):

Ebadi-Nahari Mostafa ◽

Nikzat Siahkola

Keyword(s):

Pollen Morphology ◽

Pollen Grains ◽

Polar View ◽

Polar Axis ◽

Morphological Classification ◽

Aperture Diameter ◽

Exine Ornamentation ◽

Plant Taxon ◽

Pollen Shape ◽

Palynological Study

The pollen morphology of six species of Scabiosa L. (Caprifoliaceae) from Iran has been examined by scanning electron microscopy (SEM). Pollen grains were tricolpate in S. columbaria and triporate in the rest studied species. Two types of exine ornamentation were revealed: spinulate and gemmate. The pollen shape in polar view varied from triangular to circular among investigated taxa. Statistical analysis showed that some quantitative morphological features such as polar axis (P), equatorial axis (E) and aperture diameter were main characters in identification of the taxa studied. These taxa were separated from each other using cluster analysis and placed within two clusters. Our result based on UPGMA analysis is in agreement with morphological classification and recent findings on taxonomic position of the Scabiosa.Bangladesh J. Plant Taxon. 23(2): 215-222, 2016 (December)

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