Exploring microscopic pollen morphology in herbaceous Flora: Insights and analysis using scanning electron microscopy.

Microscopic techniques can be applied to solve taxonomic problems in the field of plant systematic and are extremely versatile in nature. This study was focused on the new approaches to visualizing the imaging, tool to cover the micro-structural techniques applied to the pollen study of flowers. The current research was proposed to evaluate microscopic pollen morphological attributes using light and scanning electron microscopy of herbaceous flora from Samarkand, Uzbekistan. A total of 13 herbaceous species, classified into 11 different families were collected, pressed, and identified, and then acetolyzed their pollen to visualize under light and scanning electron microscopy. Herbaceous flora can be characterized by small to very large-sized pollen morphotypes presenting four types of pollen shapes, prolate spheroidal (six species), spheroidal (three species) and prolate and oblate (two species each). The polar diameter and equatorial distance were calculated maximum in Hibiscus syriacus 110.55 and 111.2 µm respectively. Pollen of six different types was found namely tricolporate pollen observed in seven species, tricolpate and pantoporate in two species each, sulcate in Gagea olgae and hexacolpate pollen was examined in Salvia rosmarinus. Exine ornamentation of pollen was examined tectate perforate, verrucate-reticulate, micro-reticulate, reticulate, reticulate-cristatum, gemmate-echinate, echinate-perforate, perforate-striate, rugulate, rugulate-striate, bi-reticulate, reticulate-perforate and perforate-micro-reticulate showing great variations. Exine thickness was noted highest for Rosa canina 2.9 µm and minimum in Punica granatum 0.65 µm. This study of pollen imaging visualization of herbaceous flora contributes to the opportunity for the taxonomic evaluation of and fills knowledge gaps in studies of herbaceous flora identification using classical microscopic taxonomic tools for their accurate identification. RESEARCH HIGHLIGHTS: Pollen in unexplored herbaceous flora of the Samarkand region was studied with light and scanning electron microscopic pollen study. There is a high variation in observed pollen micromorphological characters. Pollen microscopic morphology has important taxonomic value for the identification of herbaceous species.

Light and scanning electron microscopic characterization of pollen grains of some wetland angiosperms from India.

Pollen grains of 58 wetland species of angiosperms belonging to 17 families, growing in different wetlands of Sub-Himalayan biodiversity hotspots, Northern Bengal and lower Gangetic plains, India were investigated during a 4-year span of 2015-2019. Freshly collected anthers were processed through the acetolysis method and the obtained pollen grains were accurately studied under LM and SEM and properly photographed. Different attributes viz. shape, size, aperture type and exine ornamentation of pollen grains served as consistent features were used for authentic identification of the studied species. To study the phylogeny of pollen grains, characters like polarity, symmetry, aperture and exine sculpturing were found most significant for species segregation. Investigated pollen grains were mostly prolate-spheroidal, spheroidal or triangular, rarely prolate or elongated, exine psilate, granulate, reticulate or microechinate type. Most of the observable aperture of pollen grains of studied species were colporate, colpate and porate, while ulcerate and inaperturate grains were also observed in the studied aquatic members of the families Cyperaceae and Potamogetonaceae. All the gathered data were further statistically analyzed through ANOVA, PCA and Pearson Correlation Matrix to understand the interrelationship among the species. The permanent slides of identified pollen grains were deposited at the herbarium of North Bengal University [NBU] for future references. HIGHLIGHTS: Study of Pollen morphology of 58 wetland species under light & scanning electron microscopy. Unique apertures and exine ornamentation used to understand taxonomic evaluation of studied species. Pollen character supports interrelationship among the studied species. Relationship between exine thickness and the habitat of the wetland plants.

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. RESEARCH HIGHLIGHTS: Pollen micromorphology is a useful tool for classifying complicated taxa. The pollen micromorphology of 12 spineless species of Astragalus L. was studied using LM and SEM. The observed pollen characteristics aided in Astragalus L. serve for the identification and classification of taxa at specific level.

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. RESEARCH HIGHLIGHTS: Pollen diversity among honeybee flora. Highly variations observed via microscopy in pollen micromorphology. Palyno-morph has taxonomic value for the identification of honeybee floral species.

Palyno-morphological diversity of Asteraceous and Poaceous allergenic plant using microscopic techniques in lesser Himalaya-Pakistan.

In classification and identification of plant species, palyno morphological character has remain helpful for plant taxonomist. The aim to investigation this study was to identify the characteristic features of Asteraceae and Poaceae family member collected from lower Himalayas of Pakistan. Light microscope and Scanning electron microscope were used for feature study of allergenic pollen. Our study includes 10 species of Asteraceae and Poaceae family. The most dominant shape of pollen was Oblate-spheroidal, Prolate-Spheroidal, Prolate and Suboblate shape of pollen. Quantitative character of pollen includes maximum pollen diameter found in Dichanthium annulatum (46.0 µm) and minimum polar axis pollen diameter found in Parthenium hysterophorous (16.0 µm). Similarly highest value of P/E ratio was noted in Cenchrus echinatus (1.05) and smallest value of P/E ratio was observed in Erigeron bonariensis (0.88). Poaceae family member were monoporate. Character feature of exine sculpturing include Microechinate, granulate, echinate, conical base, lacunae Nanogammate, Aerolate-Scabratre, Verrucate, like variation found in exine of both family member. Highest value of pollen fertility was observed in P. hysterophorous 93%, Similarly maximum value of pollen sterility was noted in E. bonariensis and Brachiaria reptans 24%. This investigation provides the characteristic feature of allergenic pollen species and help to arrange them in define class. RESEARCH HIGHLIGHTS: Pollen has affected many people around the world. Using microscopic techniques, morpho-palynological analysis of Asteraceae and Poaceae families were recognized. LM and SEM study show both qualitative and quantitative character of pollen. Identification of allergenic pollen and microscopic identified character play important role for proper guideline of identification of pollen having allergenic potential.

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.

A spectroscopic approach to detect and quantify phosmet residues in Oolong tea by surface-enhanced Raman scattering and silver nanoparticle substrate.

There have been increasing concerns among consumers about pesticide residues in Oolong tea. This study aimed to establish surface-enhanced Raman scattering (SERS) method for rapid measurement of chemical contaminants in Oolong tea. Synthesis of SERS substrate was achieved by synthesizing silver nanoparticles (AgNPs) via a reduction method. AgNPs were spherical and highly monodispersed, which created remarkable electromagnetic fields during SERS activities to measure phosmet in the methanol-water solution and Oolong tea. Partial least squares regression models were established to predict the concentrations of phosmet in the methanol-water solution (r = 0.934; slope = 0.880; RMSEP = 1.001 mg/L) and Oolong tea samples (r = 0.927; slope = 0.938; RMSEP = 1.157 mg/kg) with the detection limit of 0.1 mg/kg. The results indicate that SERS coupled with silver nanoparticles is a fast, sensitive, and reliable method for detection and characterization of pesticide contaminants in Oolong tea products.

High-dose exposure to systemic phosmet insecticide modifies the phosphatidylinositol anchor on the prion protein: the origins of new variant transmissible spongiform encephalopathies?

Compulsory exposure of the UK bovine to exclusively high biannual doses of a 'systemic' pour-on formulation of an organo-phthalimido-phosphorus warblecide, phosmet, during the 1980s (combined with exposure to the lipid-bound residues of 'bioconcentrated' phosmet recycled back via the intensive feeding of meat and bone meal), initiated the 'new strain' modification of the CNS prion protein (PrP) causing the UK's bovine spongiform encephalopathy (BSE) epidemic. A lipophilic solution of phosmet was poured along the bovine's spinal column, whence it penetrated and concentrated in phospholipids of the CNS membranes, covalently modifying endogenous phosphorylation sites on phosphatidylinositols (PIs) etc., forming a 'toxic membrane bank' of abnormally modified lipids that 'infect' any membrane proteins (such as PrP) that are programmed to conjugate onto them for anchorage to the membrane. Thus, phosmet invokes a primary covalent modification on PrP's PI anchor which, in turn, invokes an overall diverse disturbance upon CNS phosphoinositide second messenger feed back cycle, calcium homeostasis and essential free radicals; thus initiating a self-perpetuating cascade of abnormally phosphorylated PI-PrP that invokes a secondary electrostatic and allosteric disturbance on the main body of PrP impairing tertiary folding. Chaperone stress proteins conjugate onto misfolded PrP blocking its sites of proteolytic cleavage. Fresh epidemiological evidence is presented and experimental evidence referenced that adds support to a multifactorial hypothesis which proposes that BSE is a hitherto unrecognized and previously unmanifested class of subtle chronic phosmet-induced delayed neuro-excitotoxicity in the susceptible bovine.