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

Phytochemical analysis and hepatotoxicity assessment of braised Polygoni Multiflori Radix (Wen-He-Shou-Wu)

Polygoni Multiflori Radix (PMR) is a medicinal herb commonly used in China and Eastern Asia. Recently, the discovery of hepatotoxicity in PMR has received considerable attention from scientists. Processing is a traditional Chinese medicine technique used for the effective reduction of toxicity. One uncommon technique is the braising method-also known as 'Wen-Fa' in Chinese-which is used to prepare tonics or poisonous medications. Braised PMR (BPMR)-also known as 'Wen-He-Shou-Wu'-is one of the processed products of the braising method. However, the non-volatile components of BPMR have not been identified and examined in detail, and therefore, the hepatotoxic advantage of BPMR remains unknown. In this study, we compared the microscopic characteristics of different samples in powder form using scanning electron microscopy (SEM), investigated the non-volatile components, assessed the effects of different processed PMR products on the liver, and compared the differences between BPMR and PMR Praeparata recorded in the Chinese Pharmacopoeia (2020 edition). We found that the hepatotoxicity of BPMR was dramatically decreased, which may be related to an increase in polysaccharide content and a decrease in toxic substances. The present study provides an important foundation for future investigations of the processing mechanisms of BPMR.

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.

Morpho-palynological and anatomical studies in desert cacti (Opuntia dillenii and Opuntia monacantha) using light and scanning electron microscopy

Opuntia is the most diverse and widely distributed drought resistant promising genus of family Cactaceae. The cladodes were utilized to quantify the chemical composition of these plants helpful in lignocellulose conversion and their application towards biofuel production. The present study was aimed to evaluate and compare the taxonomic relationship based on morphology, stem anatomy and palynology of important desert cacti including Opuntia dillenii and Opuntia monacantha. This study also evaluates the potential usefulness of morphological, anatomical and pollen traits using light and scanning electron microscopy. The obtained microcharacters of stem and flowers are considered diagnostic at the generic and specific levels. Some distinguishing morphological features observed were elliptical to obovate cladodes, 1-7 spines per areole and presence of glochidia in O. dillenii. Pollen and stem anatomical characters of the studied taxa are considered highly diagnostic at the generic and species levels. The epidermis has irregular and wavy cells, with straight to sinuate wall pattern and paracytic stomata. Pollen grains appear as pantoporate and prolate spheroidal having reticulate to perforate-reticulate sculpturing while exine semi-tectate to tectate. The taxonomic features studied could be valuable to elaborate and helpful in correctly identification of Opuntia species. The methods of diverse microscopic examination also providing sufficient evidence about the taxonomy of the Opuntia species.

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.

Microscopic techniques for fabrication of polyethersulfone thin-film nanocomposite membranes intercalated with UiO-66-SO3 H for heavy metal ions removal from water

Environmental remediation of heavy metals from wastewater is becoming popular area in the field of membrane technology. Heavy metals are toxic in nature and have ability to bioaccumulate in water bodies. In current study, zirconium-based metal organic frameworks (MOFs), that is, UiO-66 and UiO-66-SO₃ H with a mean diameter of 200 nm were synthesized and intercalated into polyethersulfone (PES) substrate to fabricate thin-film nanocomposite (TFN) membranes via an interfacial polymerization (IP) method. TFN membranes exhibit higher selectivity and permeability as compared to thin-film composite (TFC) membranes for heavy metals, such as cadmium (Cd) and mercury (Hg). Zirconium-based MOFs are highly stable in water and due to smaller pore size enhanced hydrophilicity of TFN membranes. In addition, TFN membrane with functionalized MOF (UiO-66-SO₃ H) performed best as compared to TFC and TFN with UiO-66 MOF. The effect of loading of different weight percentages (wt%) of both MOFs for TFN membranes was also investigated. The TFN membranes with loading (0.2 wt%) of UiO-66-SO₃ H displayed highest permeability of 9.57 LMH/bar and notable rejections of 90% and 87.7% toward Cd and Hg, respectively. To our best understanding, it is the first study of intercalating functionalized UiO-66-SO₃ H in TFC membranes by IP and their application on heavy metals especially Cd and Hg.

Palyno-morphological attributes of some selected plant species of family Asteraceae from district Dera Ismail Khan, KPK, Pakistan

The current study aimed to investigate the palyno-morphological features of Asteraceous species from District Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan. A total of 13 species were collected, pressed, identified, and examined by using light and scanning electron microscopy. Both qualitative and quantitative pollen characters were observed, that is, equatorial and polar diameter, number of pores and colpi, exine thickness, exine sculpturing, pollen shape, and P/E ratio. Pollen shapes observed in studied taxa were spheroidal, suboblate, oblate-spheroidal, and lophate-spheroidal. The aperturation patterns of pollens vary from tricolporate to tetracolporate. The maximum polar and equatorial diameter of 75-100 (87.5 ± 13.6) μm and 87.5-117.5 (102.5 ± 16.4) μm, respectively, was recorded in Echinops echinatus, while minimum polar and equatorial diameter of 20-22.5 (21 ± 1.36) μm and 22.5-25 (23.5 ± 1.36) μm, respectively, was recorded in Aster subulatus. Six types of exine sculpturing patterns were observed; echinate, micro-echinate, echinate-microreticulate, microreticulate, echinate-perforate, and scabrate. Maximum exine thickness of 8.75 μm was recorded in E. echinatus and minimum of 1.25 μm in Launaea mucronata. The pollen morphology has valuable significance in understanding the taxonomy of different plant groups and plays a central role in the correct identification and classification of Asteraceous flora at species, generic, and tribe levels.