Microscopic investigation of pollen morphology of Brassicaceae from Central Punjab-Pakistan

Palyno-taxonomic approach through light and scanning electron microscopy for the identification of herbaceous Asteraceae species from Sikaram Mountain Pak-Afghan border

Due to the diverse and rich taxa, Asteraceae needs to explore from the untouched area. In this study, the pollen study was intended to assess the taxonomic value for Asteraceous taxa growing on the Sikaram Mountain Pak-Afghan border. Both microscopic techniques (LM and SEM) play a significant role in the identification and classification of herbaceous species of Asteraceae for their taxonomic and systematic implication. Pollen was observed and measured for the 15 species of Asteraceae. For investigated taxa 15 pollen characters with size, shape, polar view, pollen type, aperture orientation, and exine sculpturing in the eurypalynous pollen. Consequently, the pollen grains are usually Tricolporate, triangular to circular in polar view, while, the shape of pollen varies from subulate, oblate, and prolate along with prolate to spheroidal whereas, sculpturing also varies from Scabrate to micro reticulate, echino-perforate, Scabrate to echinate, echinate to granulate and echinate were observed. Similarly, among the quantitative data minimum values of polar and equatorial were 15.8 ± 0.74 μm in Filago pyramidata and 17.85 ± 0.39 μm in Heteropappus altaicus was measured respectively, while; the length of the spine with the least value of 2.45 ± 0.31 μm in Hertia intermedia and highest with 7.55 ± 0.31 μm was observed in Cirsium wallichii. The Exine thickness is a minimum of 1.70 ± 0.35 μm in Launaea nudicaulis and a maximum of 5.65 ± 3.59 μm in Cirssium vulgare. In addition, the highest pollen fertility (87%) in Centaurea iberica while the highest pollen sterility (32%) was recorded in Cirsium verutum. Furthermore, clustering via UPGMA, PCA, and PCoA analysis was performed for the separation of closely related taxa. It is concluded from this research work that palynological study has a crucial role in taxonomic, pure, and applied sciences. This study can be further authenticated and improved by a Phylogenetic study based on chloroplast DNA analysis & whole genome sequencing. RESEARCH HIGHLIGHTS: Pollen ultrastructure among 15 Asteraceous taxa. Micromorphological attributes measured via LM and SEM. Exine sculpture elements patterns provide accurate identification. Taxonomic keys were developed for its systematics implications.

Microscopic (LM and SEM) visualization of pollen ultrastructure among honeybee flora from lower Margalla Hills and allied areas

Microscopic visualization of micro-morphological characters were analyzed using a scanning electron microscopic (SEM) tool, which has proven to be very successful to analyze the pollen surface peculiarities. The significant goal of this research was to perform microscopic examination of pollen of some of the most frequently visited honeybee floral species around apiaries. Micro-morphological characterization of frequented honeybees foraged plants were discussed. A total of 15 species, belonging to 11 different families were identified for the foraging activities of honeybees, namely, Lantana camara, Jatropha integerrima, Helianthus annuus, Tecoma stans, Lagerstroemia indica, Duranta erecta, Cosmos sulphureus, Hymenocollis littoralis, Moringa oleifera, Cestrum nocturnum, Parthenium hysterophorus, Volkameria inermis, Catharanthus roseus, Malvastrum coromandelianum, and Citharexylum spinosum. The microscopic slides were prepared using the acetolysis method, and the qualitative and quantitative features were measured and described using microscopic tools. The pollen type sculpture varies from psilate scabrate to echinate and colpi from tricolpate to tetracolpate. Quantitative parameters such as polar diameter, mesocolpium distance, equatorial dimensions, aperture size, spine diameter, and exine thickness were calculated using IBM SPSS Statistics 20. The exine thickness was measured at its maximum in C. roseus (3.85 μm), whereas it was at its minimum of 0.90 μm in L. indica and D. erecta. Pollen fertility was estimated to be highest in H. annus (88%). The current research validates scanning microscopic features of pollen of the honeybee floral species, which is helpful for the accurate identification and commercializing of honey production to generate revenue for beekeepers through the exploration of bee floral diversity.

Light and scanning electron microscopic observation of palynological characteristics in spineless Astragalus L. (Fabaceae) and its taxonomic significance

Palynological characterization is considered to be one of the significant taxonomic tools for the delimitation and identification of morphologically complicated taxa. Hence, the pollen morphology of 12 species of spineless Astragalus L. was examined using light and scanning electron microscopy. Studied pollen were small to medium, monad, prolate to per-prolate and tricolporate type in all studied taxa. The exine sculpturing varied from reticulate to microreticulate whereas colpus ornamentation ranged from scabrate to granulate. Furthermore, maximum polar and equatorial diameter was recorded in Astragalus leucocephalus Bunge. (45.00 μm) and A. pyrrhotrichus Boiss. (22.91 μm) while minimum in A. amherstianus Benth. ex Royle (28.75 μm) and A. amherstianus Benth. ex Royle (15.00 μm), respectively. Similarly, the ratio of polar to equatorial diameter was recorded maximum in A. ophiocarpus Boiss. (2.05). The width of colpi was larger in A. hamosus L. (1.29 μm) and smaller in A. ophiocarpus Boiss. (0.62 μm). We have also found the maximum value of mesocolpium in A. retamocarpus Boiss. (2.08 μm) while minimum in A. oxyglottis Steven ex M.Bieb. (1.87 μm). The quantitative pollen attributes helped in the development of pollen keys for the accurate and quick identification of the studied species. Furthermore, ordination and cluster analysis were performed for the differentiation of the investigated taxa at species level. Based on our results, we conclude that pollen features can be used for the delimitation and identification of the studied taxa.

Pollen morphology of selected melliferous plants and its taxonomic implications using microscopy

This research aimed to explore the melliferous bee flora pollen from arid zones of District Attock, Islamabad Capital and Rawalpindi. Morpho-palynological features has provided key information for the classification and help to explain the taxonomy of several genera and species. Therefore, in this work, we examined the morphological characters of pollen potentially to be used for the species delimitation of bee flora. A total of 18 bee floral species, classified into 12 different families were collected, pressed, identified and then acetolyized to observe the grains under microscopy. Bee pollen can be described by small, medium to large sized morphotypes presenting five types of shapes, prolate spheroidal in (seven species), sub-prolate (six species), oblate spheroidal (three species), oblate and prolate (one species each) was examined. The observed polar and equatorial diameter were found maximum in Zea mays 73.5 μm and Pelargonium inquinans 66.75 μm respectively. Pollen of six different types was found namely: tricolporate, 3-zonocolporate, monoportae, tetracolporate, tetraporate and mononsulcate. Whereas highest value of colpi length was measured in Grewia tenax (24.55 μm). Exine surface nature of pollen was examined echinate psilate and scabrate. Exine thickness noted to be maximum in Verbena tenuisecta (8.40 μm) and minimum in Citrus macrocarpa (0.4 μm). Bee floral species considered difficult to identify based on other morphological traits were successfully distinguished using pollen quantitative and qualitative traits, confirming the importance of pollen morphology to diagnose characters to correctly identify honeybee flora.

Palyno-anatomical microscopic characterization of selected species of Boraginaceae and Fabaceae

Palyno-anatomical characterization of some selected species of Boraginaceae and Fabaceae using light microscopy (LM) and scanning electron microscopy (SEM) was conducted. Six species of them belongs to four genera of family Boraginaceae and other six species belongs to four genera of Fabaceae. The current study aimed to investigate palyno-anatomical features for correct identification and taxonomic significance. Pollen grains were acetolyzed and observed both qualitatively and quantitatively through light microscopy and scanning electron microscopy. Statistical data was analyzed through cluster analysis which categorized plants into clusters. Principal component analysis (PCA) was carried out to illustrate morphological variation among selected plant species. Studied plant species showed variation in shape, size, aperture type, exine ornamentation of pollen, size and shape of epidermal cells, types of stomata, guard cells, subsidiary cells and trichome types. Exine thickness was recorded maximum 2.30 ± 0.1 μm in Lablab purpureus and minimum 1.05 ± 0.2 in Gastrocotyle hispida. PCA summarized 73.78% of accumulative variance. Trichome index was observed highest 62% on the adaxial surface of Heliotropium europaeum and lowest 21% on adaxial surface of L. purpureus. These findings reinforce the importance of palyno-anatomical features in the characterization and identification of taxa. It was concluded that description of palyno-anatomical characteristics presented in this study, highly contribute to our knowledge for correct identification of plant species.

Use of scanning electron microscopy to analyze sculpturing pattern and internal features of pollen grain wall in some members of Astragaleae (subfamily: Papilionoidae)

Palynological features of tribe Astagaleae L. have been observed with scanning electron microscopy (SEM), to assess features that can be used to re-examine the placement and taxonomic position of tribe. The palynomorph attributes of 10 species included in three genera of Astragaleae (Astragalus L., Glycyrrhiza L., and Oxytropis DC.) are investigated. The assignment of genus Oxytropis in tribe Astragaleae was also reevaluated based on pollen characters. Pollen appear to be prolate, prolate-spheroidal, and subprolate. Polar axis size (P) varies from 31.3 μm ±1 to 17.5 μm ±1.4 and equatorial axis size (E) varies from 22.2 μm ±1.8 to 13.1 μm ±0.9. Prominent apertures found consistently dispersed along the surface of pollen. Three kinds of ornamentation pattern were recorded, that is, reticulate or reticulate-perforate and perforate. The studied species display variation in equatorial and polar diameter, aperturation and sculpturing pattern, exine thickness, and pollen shape. On the basis of descriptive pollen features, a dichotomous taxonomic key and UPGMA analysis has been made for effortless and quick identification. The study concluded that disparities of the entire features are typically unrelenting and concerned with the species and shows potential systematic significance. The combination of palynological attributes in association with additional traits has prospective for systematic identification at species and genus level.

Implication of light and scanning electron microscopy for pollen morphology of selected taxa of family Asteraceae and Brassicaceae

The present study was intended to assess pollen morphological attributes of selected Asteraceous and Brassicaceous species from tehsil Esa Khel (Mianwali), Punjab using scanning electron microscopy (SEM) and light microscopy (LM) techniques for its systematic and taxonomic significance for correct identification. Pollen from 12 different species belongs to two plant families from various distributional localities were collected, acetolyzed and measured. Different palynomorphological features were investigated using LM and SEM techniques. In Asteraceous species, three types of pollen (tricolporate, trizonocolporate, and tetracolporate) were observed. Pollen shape was observed prolate-spheroidal in three species while oblate and oblate-spheroidal were detected in Parthenium hysterophorus and Erigeron bonariensis. While sculpturing pattern of exine were echinate, echinate fenestrate, echinate perforate and scabrate echinate. Mesocolpium measurement was calculated maximum for Sonchus oleraceous (16.6 μm). Brassicaceae pollen were circular, lobate, tricolpate and exine show reticulate peculiarities. Whereas dominant shape was oblate-spheroidal followed by prolate-spheroidal and sub-prolate in Lepidium didymum and Sisymbrium irio, respectively. Mesocolpium distance was noted highest in Raphanus raphanistrum (14.4 μm). Exine thickness was noted maximum in Erigeron bonariensis (2.9 μm) in Asteraceous species and in Brassicaceae; Lepedium didymum exine measurement was 2.7 μm. The study showed that pollen micromorphology has important role to accurately identify and classify diverse plants genera belong to different families. Based on these taxonomic palynomorph features, the accurate identification of species from flora of tehsil Esa Khel, Mianwali were elaborated.

Chemo-taxonomic and biological potential of highly therapeutic plant Pedicularis groenlandica Retz. using multiple microscopic techniques

Pedicularis groenlandica is one of the most important medicinal plant of Deosai Plateau (Gilgit-Baltistan) Pakistan. The present study was aim to evaluate the micromorphological features, phytochemical screening and pharmacological potential of P. groenlandica by using multiple microscopic techniques. Six different solvents were used to prepare P. groenlandica extracts. Phytochemical and antioxidant activities were determined calorimetrically. To investigate antidiabetic, α-amylase inhibition assay was performed. Cytotoxicity was tested using brine shrimp assay. Anti-leishmanial via MTT assay. Disc-diffusion assay was used for protein kinase inhibitory, antibacterial and antifungal activities. Palyno-anatomical study showed significant variation for the authentication and correct identification of this highly therapeutic plant by using light and scanning electron microscopic techniques. All extracts were found rich in phytochemicals, significant amount of phenolic and flavonoid contents were found in methanol extract (PGM) 95.78 mg GAE/g and 66.90 mg QE/g. Highest DPPH scavenging potential with IC₅₀ 88.65 μg/mL, total antioxidant capacity (60.33 mg AAE/g sample) and total reducing power (83.97 mg AAE/g) were found for PGM. Disc-diffusion method showed significant antibacterial and antifungal activities. Noticeable growth inhibition in L. tropica was displayed by n-hexane extract (IC₅₀ 112 μg/mL). Brine shrimp with highest LD₅₀ (67.65 μg/mL) in ethyl-acetate extract. Ethanol extract gives persuasive protein kinase inhibition (26 mm) against Streptomyces 85-E hyphae. Highest alpha-amylase inhibition (74.10%) was found in n-hexane extract. In conclusion, our findings scientifically support the ethno-medicinal and biological potential of P. groenlandica. In future, the plant needs to be explored for further identification and isolation of bioactive compounds to develop new drugs to treat several aliments.

Effect of necrotrophic fungus and PGPR on the comparative histochemistry of Vigna radiata by using multiple microscopic techniques

Rapid advances in the field of pathogen detection have opened new opportunities and better understanding for their management approaches. Aim of this study was to elucidate histopathological observations of different tissues affected by Macrophomina phaseolina and to observe the defense responses of plant growth promoting rhizobacteria (PGPR) in mungbean plants. Sections of the stem and root were prepared and stained with ferric chloride, Lugol's iodine and Wiesner's reagent and were then observed under multiple microscopic techniques. Results revealed that both pathogen and PGPR produce responses on the plant that include colonization of xylem vessels by hyphae and sclerotia, hypertrophy and hyperplasia of the cells, destruction of xylem fibers and amyloplasts in parenchymatous cells; and production of gels by the plant were observed. There was a significant increase in lignin and phenolic compounds deposition in stem and root sections of PGPR treated and non-treated mungbean plants. Whereas the soil amended with PGPR showed very less to no starch production. Moreover, production of gels and gums were also observed in both stem and root sections. Compared to light microscopy, scanning electron microscope provided greater depth of focus and resolution of the pathogen attack on plant tissues, associated bacteria. As a whole, the data demonstrated that inoculation of PGPR can be an effective strategy to stimulate plant growth and they could significantly activate disease resistance against M. phaseolina.

Pollen micromorphology of eastern Chinese Polygonatum and its role in taxonomy by using scanning electron microscopy

Although considerable progress has recently been made in the taxonomic study of Asparagaceae, but the Polygonatum remains one of the most poorly investigated genus. Therefore, the present study was designed with the aim, to document the pollen micromorphology of closely related Polygonatum taxa and its taxonomic significance. Pollen micro-morphological features were observed using scanning electron microscopy-SEM). The pollen grains are monad, navicular, monocolpate, and radially symmetrical. A significant variation was observed in the exine sculpturing. Moreover, most of the Polygonatum taxa have perforate pollen while some of them were mixed with psilate to perforate, perforate to microreticulate, sometimes scabrate, gemmate with baculate. Hence, this study documented the pollen morphology of Polygonatum taxa and strengthens the taxonomic identification of the genus Polygonatum based on pollen characters, which helps and can be used as an additional tool for the correct identification and discrimination of the species of Polygonatum at generic and species level.

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 (11.10 μm) 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.

Comparative evaluation of the toxicological effect of silver salt (AgNO3 ) and silver nanoparticles on Cyprinus carpio synthesized by chemicals and marine algae using scanning electron microscopy

The widespread use of silver nanoparticles (AgNPs) results in the unintentional release into the water body. Therefore, understanding of the potentially harmful impacts of AgNPs and Ag-salt on aquatic animals is a need of time. This study was design to analyze the oxidative stress and histopathological damages in Cyprinus carpio. The synthesis of AgNPs from Halymenia porphyraeformis and by reduction of chemical was done. Nanoparticles were characterized with UV-Visible spectroscopy, SEM, XRD, and FTIR analysis. The comparative toxicological effect of chemically synthesized silver nanoparticles (Ch-AgNPs), green silver nanoparticles (Gr-AgNPs), and Ag-salt on C. carpio was analyzed. For oxidative stress analysis, different tests Lipid peroxidation (LPO), catalase, glutathione reduction (GST), and glutathione S-transferase (GST) were performed. The highest LPO 245.168 ± 0.034 was recorded in Ch-AgNPs-treated gills and the lowest 56.4532 ± 0.02 was found in Gr-AgNPs-treated liver. Maximum GSH 56.4065 ± 0.13 was observed in Gr-AgNPs liver and minimum 40.781 ± 0.54 was recorded in Ag-salt gills. The maximum quantity of catalase 68.0162 ± 0.09 was noted in the Ag-salt-treated liver and the minimum was calculated 17.3665 ± 0.01 in the liver of Ch-AgNPs and highest values of GST 765.829 ± 0.11 were recorded in gills of Gr-AgNPs and lowest 633.08 ± 0.26 in the liver of Ch-AgNPs-treated fish. In conclusion, maximum destruction was found in the gills and liver of the fish treated with chemical and green AgNPs followed by Ag-salt as compared to control. The adverse effects of AgNPs and Ag-salt were probably related to the oxidative stress in the fish that lead to histopathological damage of its vital organs.

Pollen morphology of family Solanaceae and its taxonomic significance

The pollen micro-morphology of family Solanaceae from the different phytogeographical region of Pakistan has been assessed. In this study, thirteen species belonging to ten genera of Solanaceae have been studied using light and scanning electron microscopy for both qualitative and quantitative features. Solanaceae is a eurypalynous family and a significant variation was observed in pollen size, shape, polarity and exine sculpturing. Examined plant species includes, Brugmansia suaveolens, Capsicum annuum, Cestrum parqui, Datura innoxia, Solanum lycopersicum, Nicotiana plumbaginifolia, Petunia hybrida, Physalis minima, Solanum americanum, Solanum erianthum, Solanum melongena, Solanum surattense and Withania somnifera. The prominent pollen type is tricolporate and shed as a monad. High pollen fertility reflects that observed taxa are well-known in the study area. Based on the observed pollen traits a taxonomic key was developed for the accurate and quick identification of species. Principal Component Analysis was performed that shows some morphological features are the main characters in the identification. Cluster Analysis was performed that separate the plant species in a cluster. The findings highlight the importance of Palyno-morphological features in the characterization and identification of Solanaceous taxa. It is concluded that both LM and SEM significantly play a key role in correct identification of taxa studied.

Palynological characteristics of selected Lamioideae taxa and its taxonomic significance

Lamioideae comprised the second-largest subfamily in Lamiaceae. Although considerable progress has recently been made in the taxonomic study of Lamioideae, the subfamily remains one of the most poorly investigated subfamily in Lamiaceae. Therefore, the present study was designed with the aim to document the pollen micromorphology of some selected Lamioideae taxa and its taxonomic significance from Pakistan. Pollen micromorphological features were observed using scanning electron microscopy. The pollen grains are monad, tricolpate, radially/bilateral symmetrical. The pollen grains were small to medium-sized having oblate, oblate/subspheroidal, and subspheroidal shape. Exine sculpturing was observed as reticulate, microreticulate, and bireticulate. The colpus surface ornamentation was found as verrucate, gemmate, scabrate, and psilate. There was a considerable variation between the species in the micromorphology, that is, the coarseness of the reticulum, thickness of the muri comprising the reticulum and the number of secondary lumina per primary lumen. Hence, this study documented the pollen morphology of some selected taxa of the subfamily Lamioideae from Pakistan and strengthens the taxonomic identification of subfamily based on pollen characters, which helps in the correct identification, discrimination of the species of Lamioideae at generic and species level.

Quality assurance and authentication of herbal drug (Argyrolobium roseum and Viola stocksii) through comparative light and scanning electron microscopy

The quality assurance and authentication of crude herbal drugs play important role in the effective therapeutic effect of herbal drug and their products. There are many reported problems in quality assurance of herbal crude drugs concerning to their correct identification. The present study was designed with the aim to document the authentication and quality assurance of the herbal crude drugs (Argyrolobium roseum and Viola stocksii) thorough light microscopy (LM) and scanning electron microscopy (SEM). The detailed foliar anatomical studies showed polygonal epidermal cells having anticlinal walls in Argyrolobium roseum while rounded epidermal cells were observed in Viola stocksii. The anomocytic stomata type was observed in Argrolobium roseum while actinocytic was noticed in Viola stocksii. The pollen of studied species appeared as tricolporate showing reticulate exine sculpturing in Argrolobium roseum while fine perforations were recorded in Viola stocksii. Furthermore, quantitative analysis of phenols, flavonoids, and antioxidant activity showed high flavonoid and phenol content in Argyrolobium roseum as compared with Viola stocksii. It was observed that Argyrolobium roseum was discriminated from the Viola stocksii based on the leaf and pollen micromorphological traits by using LM and SEM techniques. It was concluded that LM and SEM techniques were found useful for the quality assurance of botanicals and their authentication.