Pollen Shape Research Articles

Morpho-palynological assessment of some species of family Asteraceae and Lamiaceae of District Bannu, Pakistan on the bases of light microscope & scanning electron microscopy.

Pollen micro-morphological features have proven to be helpful for the plant taxonomists in the identification and classification of plants. The aim of this study was to evaluate the palynological features of family Asteraceae and Lamiaceae from flora of District Bannu, Khyber Pakhtunkhwa, Pakistan using both scanning electron microscopy (SEM) and light microscope (LM) for their taxonomic importance. Pollen of seven Asteraceous species belonging to four genera and four Lamiaceae species categorized into four genera were collected from different localities of research area. The present research work provides detailed information of diverse morpho-palynological characters both qualitatively and quantitatively including pollen shape, type, diameter, P/E ratio, exine sculpturing and thickness. Type of pollen in Asteraceae and Lamiaceae was ranged from tricolporate, tricolpate, trizonocolpate and hexazonocolpate. The maximum polar diameter (40.05 μm) and equatorial diameter (37.66 μm) was observed in the Ajuga bracteoosa while minimum polar and equatorial diameter was noted in Isodon rugosus (11.10μm) and Erigeron canadensis (13.20 μm) respectively. Sculpturing of exine include; echinate, reticulate scabrate, aerolate, reticulate-verrucate, reticulate-scabrate, perforate and reticulate to perforate. Exine thickness was examined maximum 1.50 μm in Helianthus tuberosus, whereas minimum in Conyza Canadensis (0.16 μm). The pollen fertility was found highest in C Canadensis (83.33%) and lowest in Ajuga bracteosa (58.06%). The observed pollen morphology has many valuable qualitative and quantitative attributes for the better understanding of their taxonomy and play significant role in correct identification.

Meiotic behavior and diploidy in Schinus terebinthifolia (Anacardiaceae)

Abstract The genus Schinus (Anacardiaceae) comprises 30 species found in Peru, Bolivia, Chile, Paraguay, Uruguay, Argentina and Brazil. Schinus terebinthifolia (Brazilian pepper tree) is socioeconomically important in the Brazilian state of Espírito Santo. Dried fruit is used as a pepper-like spice and natural populations are exploited. Studies on the meiotic behavior and pollen stainability from an ecological and evolutionary point of view are essential, since they can promote future sustainable management strategies for this species. The objective was to evaluate meiotic behavior and characteristics of pollen grains of individuals from a natural population of S. terebinthifolia localized in the municipality of Vitória, Espírito Santo state, Brazil. Young anthers were squashed in 1% acetocarmine dye to obtain the pollen mother cells. The pollen stainability with 1% acetocarmine, Lugol’s iodine solution and Sudan IV and pollen shape were used to assess the pollen potential viability, cytochemistry and morphology. All individuals had a gametic number of n = 7, a regular meiotic behavior and so the somatic number is 2n = 2x = 14 chromosomes. Median pollen stainability was 94%. Pollen grains are dispersed as monads, 3 - colporate and subspheroidal. The exine has striate-reticulate ornamentation. Pollen grains are starch positive and lipid negative. This is the first report of the occurrence of diploidy for the species. The high pollen stainability is the result of the occurrence of regular meiosis. The presence of starch as pollen reserve can increase the resistance of pollen grains to hostile environments in this species.

Pollen morphology and its systematic value to southern South American species of Lepidaploa (Vernonieae: Asteraceae)

Abstract Palynological data have been used in Vernonieae for generic and specific delimitations, particularly in the Lepidaploinae subtribe. For this reason, pollen studies in the genus Lepidaploa are important to solve taxonomic conflicts. We characterized 23 species of Lepidaploa searching for morphological differences among themselves. We then compared the data obtained with other genera of the Lepidaploinae. The results show that the species have pollen type “C” (with polar lacuna) or “G” (without polar lacuna), oblate-spheroidal, subprolate or prolate-spheroidal, 3-colporate and equinolophate. The pollen types and shape of pollen grain are taxonomically useful. Pollen morphology is useful to distinguish species and genera of Lepidaploinae. Together with macromorphological data it is possible to delimit Lepidaploa and the species studied here.

Pollen morphological assessment of specific selected species of district Sheikhupura, Punjab, Pakistan under LM and SEM

Around 30 pollen samples, 16 families and 25 genera that were gathered, identified and preserved from 6 different localities of District Sheikhupura. Light and scanning electron microscopy was done for all collected flora. Out of the total samples, 43% specie was identified as herbs, 23% as shrubs, and 33% were identified as trees. The flora was both wild and cultivated. Wild plants were 33%, cultivated 40% and 26% of them were both wild and cultivated. Qualitative and Quantitative survey of pollens revealed polar shape of pollens were 37% spheroidal, 20% prolate spheroidal, 17% oblate spheroidal, remaining were rectangular and pecolpate. Sexine and nexine were available in 100% of samples. Thirty-three percentage of pollen grains were having spines on them. The presence of spines on pollen grains represents the evolutionary relationship amongst the plants. Current study was conducted to record and analyze palynomorphic diversity in district Sheikhupura, Punjab, Pakistan.

Use of Pollen Morphology Traits for Identifying Species of Centaurea L. Asteraceae in Kurdistan-Iraq

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.

Application of multimicroscopic techniques (LM and SEM) in comparative palynological study of Asteroideae members, inhabited in Pakistan.

In the present study light and scanning electron microscopic approaches were used to study the palynological variations among 30 Asteroideae members. Variety of qualitative and quantitative palynological characters like pollen shape and type, pollen sculpturing, pollen size, P/E ratio, exine and intine thickness, interspecific difference, colpi size, pore size, spines length, spine width, and pollen fertility were observed. Results reported remarkable variations among pollen characters of studied taxa. The shape of pollen grains in polar and equatorial views varied from specie to specie such as spheroidal, prolate, oblate, subspheroidal, oblate spheroidal, prolate spheroidal, suboblate, and sub prolate. Bidens pilosa L. showed maximum pollen size in both polar and equatorial views, whereas minimum pollen size in polar view was found in Tetraneuris scaposa (DC.) Greene. (i.e., 30.5 μm) and in equatorial view was found in Cosmos sulphureus Cav. (25.5 μm).The highest P/E ratio (1.39 μm) was measured in Glebionis coronaria L. The values of exine and intine thickness also varied. Tricolporate, tetracolporate, trizonocolporate, pentoporate, and polypentoporate pollen types were examined. Spinateand echinate pollen sculpturingobserved under SEM. Variations in spine length and width also recorded. The maximum pollen fertility (98%) was measured in Chrysanthemum morifolium Ramat. and the lowest (56%) was recorded in Thymophylla tenuiloba (DC.) Small. It was concluded that the variations in qualitative and quantitative characters were seemed to be valuable for the taxonomic investigations of Asteroideae taxa.

Pollen morphology of the some taxa belonging to Veronica L. (Plantaginaceae) and Its taxonomic importance

In this study, the genus Veronica L. (Plantaginaceae) from the Plantaginacae family V. bozakmanii M.A.Fisch., V. triphyllos L., V. persica Poir., V.triloba Opiz., V. anagallis-aquatica L., V. oxycarpa Boiss., V. cinerea Boiss. & Balansa., V. macrostachya Vahl. subsp. mardinensis (Bornm.) M. A. Fisch., V. orientalis L. subsp. orientalis, V. orientalis L. subsp. nimrodi (Richt. ex Stapf) M.A. Fisch taxa were investigated in terms of palynological features. The specimens of this taxa were collected during the field surveys were investigated using Light Microscope (LM) and Scanning Electron Microscope (SEM). As a result of this study some common traits of the taxa found out such as polen tectate, the pollen shapes being subprolate, prolate and the symmetry being heteropolar. Also, the type of the aperture is tricolpate. The SEM microphotographs shows that the ornamentations are reticulate, scabrate-perforate and striate-microreticulate.

Diversity of Sambucus nigra pollen within Slovakia in selected morphological characters by SEM study

This study analyzed pollen morphology and characteristics of 20 Sambucus nigra L. genotypes from populations of various ecotypes and geographical localities from the territory of Slovakia. We used principal component analysis to explore variability in pollen grain size (polar and equatorial diameter), shape, aperture type, and exine ornamentation by scanning electron microscopy. The combination of these morphological characteristics and ultrastructure allows us to determine the differences or similarities between the same and various species and genotypes, which may be a useful tool for systematics with significant diagnostic value. The findings confirmed small differences among the genotypes in measured traits with polar and equatorial diameters in the range from 22.30 to 26.64 μm and from 12.81 to 14.45 μm, respectively. Shape index (P/E ratio) depending on elongation or roundness of pollen grains varied from 1.66 to 2.02. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) of morphological data helped to compare evaluated morphometric parameters and identified three closely related groups. It was noted that the diversity of surface sculpturing of pollen grains in combination with their shape and size enables us to use a complex of fine morphologic signs for S. nigra pollen identification. Pollen data combined with other morphological evidence (e.g., floral characters) have more recently become an important indicator of which genotypes may be the best representatives of species.

Scanning electron microscopy observations of pollen morphology in common vetch (Vicia sativa) subspecies

AbstractCommon vetch (Vicia sativa) is an important forage and green manure crop that is widely cultivated around the world. However, the large number of subspecies and accessions of common vetch has made taxonomic research on this species difficult. Pollen morphology data can provide important evidence in the study of plant phylogeny. Therefore, in this research, light microscopy and scanning electron microscopy were used to observe seven morphological traits of pollens from 22 common vetch accessions, and residual maximum likelihood and pattern analysis was conducted. The results showed that the pollen grains of the 22 accessions were all monad pollen and the polar view revealed three-lobed circular and triangular shapes, while the equatorial view mainly revealed an oblate shape; only one accession showed an oblate spherical shape. All accessions were 3-zonocolporate and the colpus length extended close to the poles. The polar axis length was (19.39 ± 0.97)–(42.12 ± 0.76) μm and the equatorial axis length was (35.97 ± 1.27)–(45.25 ± 0.81) μm. We found that qualitative traits of pollen shape, aperture polar view and ornamentation were highly stable. Among them, polar axis length, equatorial axis length and colpus length and width had significant differences among the accessions. The ratios of the equatorial and polar axes had significant differences among the subspecies. This trait information could be used for the classification and identification of common vetch accessions and subspecies.

Türkiye İçin Endemik Bir Bitki Olan Cousinia foliosa Boiss. & Bal. (Asteraceae) Üzerine Anatomik ve Palinolojik Bir Çalışma

Cousinia Cass. cinsi Asteraceae familyasının en büyük cinslerinden biri olup yaklaşık 700 türle temsil edilmektedir. Bu çalışma, Stenocephalae Bunge seksiyonu içerisinde yer alan Cousinia foliosa türünün anatomik ve palinolojik özelliklerinin belirlenerek cinsin sistematiğine katkı sağlamak amacıyla yapılmıştır. C. foliosa türünün polen mikromorfolojik özellikleri çalışılmış ve türe ait fotoğraflar verilmiştir. Bu türün anatomik çalışmasında gövde, yaprak ve orta damar özellikleri tespit edilerek fotoğrafları verilmiştir. Anatomik çalışmalar için bitki kısımları parafine gömülmüş ve dokuların boyanma işlemi için safranin fast green boyama metodu uygulanmıştır. Anatomik karakterlerden orta damar şeklinin dairemsi ve orta damardaki iletim demeti sayısının 8 olmasıyla bu karakterlerin türlerin ayrımında önemli olduğu belirlenmiştir. Palinolojik çalışmalar için ışık mikroskobu kullanılmış ve polen şekli subprolat olarak tespit edilmiştir. SEM mikroskobu kullanılarak polen ekzin yüzey süslerinin fotoğrafları çekilmiş ve polenlerin verrukoz olduğu belirlenmiştir.

Pollen Morphology and Variability of Abies alba Mill. Genotypes from South-Western Poland

The objective of this study was to investigate pollen morphology and ranges of intraspecific variability of Abies alba Mill. Pollen grains were collected from nine clonal seed orchards of A. alba in the Sudety Mountains, (South-Western Poland). At each seed orchard, 4–6 grafts were selected. Each individual (graft) was represented by 30 pollen grains and 1440 pollen grains were measured totally. Eight quantitative and four qualitative features of pollen grains were analysed. The diagnostic features of pollen grains for the studied species were: Exine surface of pollen corpus (cappa and leptoma) and sacci, the length of the polar axis (P), pollen shape (P/E ratio), and a new trait—saccus shape (A/B ratio — saccus width (A) to his length (B)). Pollen features made possible to differentiate seven individual genotypes (samples). To our knowledge, this is the first time that the intraspecific and interindividual variability of pollen grains of A. alba were investigated. The most different were the pollen grains from samples—genotypes 13 (Bystrzyca Kłodzka) and 18 (Jugów), and also (although to a lesser extent) genotypes—11 (Kamienna Góra), 30, 31 (Jugów), and 44 (Szklarska Poręba). No significant relationships were observed between the pollen grain traits and the geographical location of the collection sites.

Variability of eight Algerian oleaster ecotypes (Olea europaea subsp. europaea var. sylvestris [Mill.] Lehr): pollen and exine morphology in relation to geo-climatic effect

Pollen characters of the Algerian oleaster (Olea europaea subsp. europaea var. sylvestris [Mill.] Lehr) from eight ecotypes were analysed to evaluate the geo-climatic effect of their environment. Samples were collected along an altitudinal gradient from western to central Algeria. Eighteen morphological characters of the pollen grains were studied using scanning electron microscopy (SEM). The results show significant inter-populations variability. The geo-climatic conditions, duration and timing of dry periods vary from one area to another. Depending on the area, the length of the dry period (P p ≤ 2T) coincides more or less with anthesis periods. No significant geo-climatic effects on exine parameters were detected, except for lumina density (LD) and mean lumina diameter (Lm). However, polar axis (P), pollen size index (PSI) and pollen colpis length (PCL) were found to be related to latitude, longitude and temperature. LD and Lm were strongly linked to the pollen parameters, resulting in variation in pollen shape and size. Depending on the geo-climatic conditions, three morphotypes appear. The morphotype from a site with high temperature, low humidity associated with a long dry period is characterised by small pollen size, low lumina surface area and high lumina density/100 μm2 and vice versa. The results indicate that the exine has played an important role in the environmental adaption in these wild populations.

Application and implication of scanning electron microscopy for evaluation of palyno-morphological features of Vitaceae from Pakistan.

The present study aimed to investigate the palyno-morphological features of species of family Vitaceae from Pakistan. A total of nine species, belonging to four genera were collected, pressed, identified, and then analyzed microscopically. Both quantitative and qualitative characters of the pollen grains were recorded including polar and equatorial diameter, P/E ratio, number of colpi and pores, exine thickness and shapes of the pollen in both polar and equatorial view, and exine sculpturing using Leica microscope fitted with camera Meiji Infinity 1 and then analyzed statistically using software IBM SPSS Statistics 20. The results of the present study demonstrated the variations in polar and equatorial diameter, exine thickness, P/E ratio, pollen shape, and exine sculpturing of the studied species and highlighted the significance of pollen morphology as an identification tool. The present study may contribute to better understand the classification at genus level, which will support the future phylogenetic characterization of the family.

Pollen diversity and its implications to the systematics of mimosaceous species by LM and SEM.

In this study we have discussed pollen morphology of 14 mimosaceous species belonging to five genera by using light microscopy (LM) and scanning electron microscopy (SEM). The palynological features of species were determined by both qualitative and quantitative characters. The qualitative characters include pollen shape, colpi arrangement, and exine sculpturing. Oblate spheroidal shaped pollens were noted in Albizia procera, Albizia lebbeck, Acacia tortilis, Acacia ampliceps, and Acacia modesta, subprolate shaped pollen in Leucaena leucocephala, Prosopis julifera, and Acacia nilotica, prolate pollen in Acacia farnesiana and Prosopis glandulosa while spheroidal, sub spheroidal and sub oblate pollen grains were observed in Acacia catechu, Mimosa himalayana, Prosopis cineraria, respectively. Sparsely foveolate, reticulate, scabrate, and scrobiclate exine sculpturing were observed. Colpi with sunken ornamentation were seen in P. cineraria, P. glandulosa, P. juliflora, and L. leucocephala while colpi were absent in rest of the studied species. The quantitative characters were statistically studied using SPSS software. The current study gives important morpho-palynological characters for identifying and validation of close related and similar taxa which will aid to the phylogenetic analysis of Mimosaceae family.

Pollen morphology of Helianthemum caput-felis Boiss. (Cistaceae)

The external pollen morphology of Helianthemum caput-felis Boiss. (Cistaceae) was studied from nine populations covering the whole distribution range in the western Mediterranean Basin, using light and scanning electron microscopy. Pollen grains are medium sized, radially symmetrical and tricolporate, and the pollen shape varies from sub-prolate to prolate-spheroidal. According to the exine ornamentation, three main pollen subtypes were recognised: striato-microperforate, microreticulate and rugulato-microperforate. The pollen data demonstrate that the populations of North Africa, as well as one population of the Spanish island of Majorca (Sa Ràpita), show similar micro-reticulate exine ornamentation. The other Spanish populations of Alicante, Colònia de Sant Jordi (Majorca), as well as those of the Italian area of Capo Mannu (Sardinia), show a striato-microperforate pollen type, while the population of Su Tingiosu (Sardinia) shows a rugulato-microperforate pollen type. The different characteristics of the exine ornamentation make it a valuable parameter to distinguish the different populations in the distribution range. Our results suggest an evolutive differentiation by the geographical isolation of the species within the Mediterranean Basin.

Key distinguishing characters (KDCs) of official (Boerhaavia diffusa L.) and commonly mistaken (Trianthema portulacastrum L.) sources of Mukkirattai of Siddha

Boerhaavia diffusa L. has been used extensively in Siddha system of medicine and is often confused with Trianthema portulacastrum L. due to morphological similarities. This particular study compares, analyses and identifies the key distinguishing features of the two whole plant drugs based on pharmacognostical and phytochemical aspects. The samples were studied for macroscopy, microscopy, physicochemical analysis, preliminary phytochemical analysis and HPTLC following standard procedures. Macroscopic studies showed few notable differences in macro-microscopy of root, stem, leaves and flowers of both the plants. Microscopically root, stem, leaf and petiole of both the plants showed differences in layers of cork, presence of crystals and medullary rays (in root), the thickness of cuticle, cortex and arrangement of vascular bundles (stem), presence of characteristic type of trichomes (leaf) and shape of the petiole. Powder microscopy showed differences in epidermis, crystal types and shape of pollen. Preliminary phytochemical analysis showed the presence of phenol, saponins and coumarins in B. diffusa and was not detected in T. portulacastrum. There were significant differences in the values of quantitative microscopy, physicochemical parameters and HPTLC of both the whole plant samples. The finding of this study will be helpful for the correct identification of the plant.

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.

Morphological characteristics of male reproductive organs in some walnut (Juglans regia L.) genotypes

Morphological characteristics of male reproductive organs (catkins, male flowers, anthers, and pollen) were studied in six walnut genotypes. Morphology and ultrastructure of pollen grains were studied using scanning electron microscopy (SEM) technique. Numbers of catkins per shoot and node ranged 2.35–5.61, and 0.29–0.73, respectively. They were higher in protandrous genotypes, compared with protogynous ones. The average values for catkin characteristics for all genotypes were: length 120 mm, width 15 mm, and the number of male flowers in catkin 120. Catkin length was higher in genotypes with the later time of pollen shedding. The average number of stamens in a male flower for all genotypes was 19, while average anther dimensions were: length 2.32 mm, width 0.96 mm, and thickness 0.75 mm. Significant differences between genotypes were found for all catkin and anther characteristics, except for catkin width. Pollen grains of all examined walnut genotypes were isopolar and pantoporate. They are classified as medium-large in size, with the average length of the polar axis (P) 36.84–39.88 μm, and the average length of the equatorial axis (E) 43.12–46.37 μm. The average P/E ratio varied between 0.85 and 0.88 and, based on this, pollen shape was identified as suboblate. All studied genotypes had microechinate exine ornamentation. The number of microechini per an area of 100 μm−2 of the exine surface varied between 22 and 25. Results obtained by SEM examination indicated that some pollen characteristics, such as size, shape, and microechini density can potentially be used in the identification of walnut genotypes.

Pollen’s contributions to Siberias forests

How pollen shapes forests and forestry can be illustrated using Siberia’s boreal forests which have historically produced some of the highest pollen concentrations in the Northern Hemisphere. Pollen’s contributions are categorized as follows: 1) forests and timber, 2) nontimber products and services and 3) emerging research at the forest-atmosphere interface. Examples are drawn from Pinus sylvestris (Scots pine), Pinus sibirica (Siberian stone pine) and Pinus koreansis (Korean pine). Pine pollen is not only vital to timber and nontimber products but it serves as a well-studied model system for atmospheric studies.

Pollen morphology and variability of the Rosa L. species of Western Himalaya in India

The present study aimed to understand the pollen morphological variation among and within the Rosa L. species of Western Himalaya, India, and to investigate whether the pollen characters may help to distinguish these species of roses. The pollen morphology of nine Rosa species viz. R. canina L., R. centifolia L., R. damascena Mill., R. foetida var. persiana (Lem.) Rehder, R. moschata Herrm, R. multiflora Thunb, R. nanothamnus Boulenger, R. webbiana Wall. ex Royle, and R. macrophylla Lindl were studied. A total of 31 accessions of roses were collected from Jammu and Kashmir, Ladakh, and Himachal Pradesh. Ten quantitative characters, i.e., length of the polar axis (P), length of equatorial axis (E), exine thickness (Ex), length of colpi (LeC), width of striae (Sr), width of groove (Gr), number of striae (Ns), Polar area index (PAI) and P/E ratio were studied. The measurements and observations were carried out with both light microscopy and scanning electron microscopy. Pollen grains of all the studied species were tricolporate. Prolate and subprolate shapes were the dominant pollen shape types. The highest and lowest polar axis length was observed for R. canina (32.73 µm) and R. moschata (25.42 µm), respectively. The average colpi length in the studied species was 22.19 µm, with R. macrophylla having a minimum length of 13.42 µm and R. canina with a maximum length of 34.03 µm. Results of the principal component analysis indicated that the principal component (PC1) attributed 42.10% of the total variation, and positively associated with P, E, LeC, and Ns. Exine ornamentation almost distinguished all the species of Rosa in this study.