Populus Ciliata Research Articles

Comparative analysis of substrate components, nutritive value, ergosterol distribution, and vitamin D2 enrichment in shiitake mushrooms cultivated on wood substrates

This study investigated shiitake [Lentinula edodes (Berk.)] mushrooms cultivated on seven hardwood and two softwood substrates for production, compositional changes, nutritive value, and ergosterol conversion to vitamin D2 content. The findings demonstrated higher shiitake yields with hardwood species, particularly among Populus ciliata (PC) (163±10.7 g/kg) and Mangifera indica (MI) (112±7.14 g/kg) substrates. Shiitake mushrooms widely utilized hemicellulose (8.93–61.3 %) during mycelial growth, while cellulose (11.9–38.0 %) and lignin (6.66–63.2 %) were mainly consumed during fruiting body development. Additionally, optimization studies on ergosterol conversion to vitamin D2 indicated that 30 KJ m−2 of UV-B exposure significantly enhanced the vitamin D2 content (99.8±2.6 µg/g). Shiitake mushrooms showed a significant difference in ergosterol content (p<0.01) when cultivated on various substrates, with the highest content found on PC (6820±720 µg/g) and Tectona grandis (6810±480 µg/g). Further, the ergosterol conversion rate to vitamin D2 was the highest in the MI substrate (4.39 %), followed by Jacaranda mimosifolia (2.87 %), and was recorded lowest in the Grevillea robusta (1.6 %) substrates. Shiitake mushrooms cultivated on different wood substrates have also shown significant differences (p<0.05) in their nutritional composition. Overall, the study highlights the potential of shiitake mushrooms cultivated on various wood substrates to provide significant nutrients and vitamin D2 content.

A study on the distribution, origin, and taxonomy of Populus pseudoglauca and Populus wuana

AbstractTaxonomy of Populus is a challenging task, especially in regions with complex topography, such as the Qinghai–Tibet Plateau because of the effect of hybridization, incomplete lineage sorting, phenotypic plasticity, and convergence. In the Flora of China, Populus pseudoglanca and Populus wuana are classified into sect. Leucoides and sect. Tacamahaca, respectively, but their taxonomy remains unclear. By conducting a systematic investigation for all taxa of Populus on the plateau, we found 31 taxa from the two sections. Through identification based on morphology and habitats, we confirmed that the “P. pseudoglanca” recorded in the Flora of Sichuan is not true P. pseudoglanca, while P. pseudoglanca and P. wuana recorded in the Flora of China may refer to the same species. By performing whole‐genome re‐sequencing of 150 individuals from the 31 taxa, we derived 2.28 million single nucleotide polymorphisms (SNPs). Further genetic and phylogenetic analyses demonstrated that the genetic structure of P. wuana is extremely consistent with P. pseudoglanca, and they all originate through the natural hybridization between Populus ciliata in sect. Leucoides and Populus curviserrata in sect. Tacamahaca. Our results suggested that P. wuana should be merged with P. pseudoglanca taxonomically. This study not only clarifies the taxonomic confusions related to P. pseudoglanca and P. wuana but also provides a new framework based on the integration of morphology, distribution, habitat, and genome to solve complex taxonomic problems.

Roost characteristics of Indian flying fox along urban noise gradient: A case study in Sallaghari Forest, Kathmandu Valley, Nepal

The Indian flying fox, Pteropus medius is a fruit bat that contributes significantly to seed dispersal and pollination services. These bats face serious threats from the loss of roosting trees due to urbanization and deforestation. This study aimed to assess the roost characteristics of Indian flying foxes and the effects of anthropogenic noise on roost tier selection in an urban forest patch. We carried out population surveys of Indian flying foxes in the Sallaghari Forest in Kathmandu Valley, Nepal by direct roost count method from July to November 2023. Further, we quantified the intensities of anthropogenic noise at every five-meter interval along the transects from the forest edge towards the main forest and recorded the minimum roosting heights at each point. Indian flying foxes were found to be roosting on trees belonging to six species. Eucalyptus sp. was the most abundant roost tree (50%) in the forest whereas the highest relative abundance of roosting Indian flying foxes was on Populus ciliata (40.1%). The regression analysis revealed that tree DBH and height and the combined interaction of height and canopy cover significantly increase the abundance of Indian flying foxes. The noise intensity at ground level and roosting height of Indian flying foxes showed a significant strong positive relationship indicating their roosting at higher tier under intense noise. We recommend measures for reducing anthropogenic noises and conserving large and tall trees to ensure the roosting habitat of Indian flying foxes in urban setups.

Equilibrium, kinetic and thermodynamic studies for the purification of wastewater from Congo red using simple and low cost adsorbents

AbstractThis manuscript reports the purification of wastewater from Congo red (CR) by adsorbing it on sawdust of Pinus walichiana (PW) and Populus ciliata (PC) used as adsorbents. The adsorbents were characterized by Field emission scanning electron microscopy (FESEM), Energy dispersive X‐rays (EDX) spectroscopy, X‐rays diffraction (XRD) and BET surface area and pore size analysis. Different adsorption models like Langmuir, Temkin, Freundlich and Dubinin‐Radushkevich (R‐D) were applied to the system. The adsorption of CR on sawdust of both plants followed Freundlich adsorption isotherm to greater extent than Langmuir and Temkin isotherms which means that the surface of adsorbents was mostly heterogeneous and there occurred adsorbate‐adsorbate interaction which influenced the adsorption process. The process also obeyed D‐R model and mean free energy of adsorption was calculated to be 7.11 kJ.mol‐1 showing that the process of adsorption was physical. Adsorption of CR on both adsorbents followed film diffusion, particle diffusion, pseudo first order and Elovich models. It means that the process of adsorption was mixed diffusional in nature, occurred through physical process, the sites for adsorption increased exponentially with adsorption and multimolecular layer was formed on the surface of adsorbents. ∆H was 3.77 kJ.mol‐1 and 15.92 kJ.mol‐1, ∆S was 19.49 kJ.mol‐1 and 85.91 kJ.mol‐1 while ∆G was (‐1.75 to ‐2.33) kJ.mol‐1 and (‐8.39 to 10.97) kJ.mol‐1 for PW and PC, respectively. It means that the adsorption process was endodermic, resulted in increase in entropy and spontaneous for both the adsorbents. Isoelectric point (IEP) was determined by salt addition method, and it was found to be 6.9 for sawdust of PW and 5.1 for PC. The process of adsorption was found to be higher in the low pH range for both the adsorbents.

Curative potential of Populus ciliata Wall ex. Royle extract against adjuvant-induced arthritis and peripheral neuropathy in Wistar rats.

Populus ciliata (PCCR) is traditionally used to treat muscular swelling, inflammation, pain, and fever. The current study was designed to validate the potential of aqueous ethanolic extract of the plant against inflammation, peripheral neuropathy, and pain in arthritic rats. The PCCR was chemically characterized by gas chromatography-mass spectroscopy and high-performance liquid chromatography. In vitro antioxidant, and in vitro anti-inflammatory assays were carried out on PCCR. For anti-arthritic potential, Wistar rats' rear paws were injected with 0.1ml Complete Freund's Adjuvant using methotrexate (3mg/kg/week) as standard control. PCCR at 100, 200, and 400mg/kg was given orally to arthritic rats for 21days. The PCCR exhibited significant inhibition of bovine serum albumin denaturation (IC-50: 202.1µg/ml), egg albumin denaturation (IC-50:553.5mg/ml) and RBC membrane stabilization (IC-50: 122.5µg/ml) and antioxidant (IC-50 = 49.43µg/ml) activities. The PCCR notably decreased the paw diameter and increased body weight of treated arthritic animals as equated to diseased control. The treatment notably (p < 0.05-0.0001) decreased malondialdehyde, and increased superoxide dismutase, reduced glutathione, and catalase in the liver and sciatic nerve homogenate in compared to diseased rats. The PCCR treatment remarkably (p < 0.05-0.0001) regulated the levels of nor-adrenaline and serotonin in sciatic nerve in contrast to diseased rats. Treatment with PCCR improved the motor activity, pain, ligament degeneration, and synovial hyperplasia in arthritic rats. Moreover, PCCR significantly (p < 0.01-0.0001) decreased the IL-6 and TNF-α. It is evident from the current study that PCCR had ameliorated polyarthritis and peripheral neuropathy through reduction of inflammatory markers, and improvement of oxidative stress might be due to presence of phenolic acids, flavonoids, phytosterols, and other fatty acids.

Wood Fiber Characteristics of Underutilized Poplar Species and Comparision with P. deltoides in Terms of their Pulp and Paper Quality

The pulp and Paper industries are growing at a tremendous rate. To satisfy the raw material supply and sustainability of their future industries need an alternative resource from fast-growing tree species. Poplar is one of the world’s fastest-growing lightwood trees with its used in several industries. The present work relies on the comparative fiber morphological dimensions of four species of poplar i.e. Populus alba L, Populus ciliata Wall. ex Royle, Populus euphratica Oliv, and Populus nigra L. The quality of pulp and paper was directly related to the fiber dimensions i.e., fiber length, fiber lumen diameter, and fiber wall thickness. A number of wood properties related to paper quality were also derived from the fiber dimensions including the Runkel ratio, flexibility coefficient, solid factors, luce’s-shape factors, slenderness ratio and wall coverage ratio. The mean value of fiber length, fiber diameter, fiber wall thickness and basic density of these four species ranged from 919-1425 μm, 19.71-25.85 μm, 2.72-4.99 μm and 0.38-0.54 g cm⁻¹ respectively. The prominent objective was to compare the fiber quality of these four poplar species within among self and also with an exotic poplar species Populus deltoides and other fast-growing tree species.

In-vitro antimicrobial, antioxidant, anti-inflammatory, and cytotoxic activities of Populus ciliata bark and leaves: A comparative study

Populus ciliata Wall. ex Royle (Salicaceae family) is a fast-growing, multipurpose native tree of the Himalayas. Traditionally, the tree's bark is used for blood purification, treatment of rheumatism, and fatigue, and to relieve the pain of menstrual cramps. The present study deals with screening crude methanolic extracts and fractions (n-hexane, chloroform, ethyl acetate, and n-butanol) of P. ciliata bark and leaves for total polyphenolic contents, antioxidant, antimicrobial, anti-inflammatory, and cytotoxic activities. Results showed that among all tested samples, the bark ethyl acetate fraction had the highest polyphenolic contents and strong antioxidant potential (DPPH 25.75±3.60 µg/mL; ABTS 33.55±2.96 µg/mL; FRAP 70.39±1.75 µM of Fe equivalents). The HPTLC analysis confirmed the presence of gallic acid, salicin, and quercetin molecules in the extracts and different fractions of P. ciliata whereas ethyl acetate fractions showed their maximum quantity. The ethyl acetate fraction of bark also revealed higher antibacterial activity against Pseudomonas aeruginosa (MIC 0.0156 mg/mL), Klebsiella pneumoniae and Staphylococcus aureus (MIC 0.0312 mg/mL), Bacillus subtilis and Escherichia coli (MIC 0.0625 mg/mL), and antifungal activity against Fusarium oxysporum (MIC 0.125 mg/mL) and Rosellinia necatrix (0.250 mg/mL), whereas butanol fraction of bark showed maximum antifungal activity against Candida auris (MIC 1.25 mg/mL). The highest anti-inflammatory activity was observed in bark ethyl acetate fraction (IC50 0.113±0.017 mg/mL for egg albumin and 0.160±0.014 mg/mL for bovine serum albumin assay) in comparison with other extracts and fractions. Additionally, bark crude extract and its ethyl acetate fraction were observed more effective against colon cancer cell lines (IC50 values <0.170 mg/mL for HCT-116 and <0.340 mg/mL for SW-620). The study concludes that the bark ethyl acetate fraction is the most biologically active fraction due to a higher number of polyphenolic contents (salicin, gallic acid, and quercetin) and among both plant parts, bark has a higher medicinal value than leaves. Therefore, this fraction can be further explored to extract biologically active compounds of pharmaceutical, food, and cosmetic values.

Cardioprotective, hypotensive and toxicological studies of Populus ciliata (Wall. ex Royle)

Populus ciliata Wall ex. Royle has folkloric repute to treat various cardiovascular ailments and related disorders. The current study was designed to evaluate the toxic profile, cardioprotective and hypotensive effects of Populus ciliata (Wall. ex Royle). Populus ciliata crude ethanolic extract (Pc. Cr) and its aqueous (Pc. Aq) & organic (Pc. Dcm) fractions were tested on isolated aorta of rat and rabbit having intact and non-intact endothelium respectively. Pc. Cr & Pc. Aq relaxed the contractions induced by PE (1 µM)-induced and K+ (80 mM)-induced on aorta, possibly by mediating endothelium derived relaxing factor (EDRF) in intact endothelium and voltage dependent L-type calcium channels blocking (CCB) mechanism in non-intact endothelium. Pc. Cr showed anti-hypertensive & cardioprotective activity by decreasing force of contraction & heart rate on isolated rabbit paired atria and reduced blood pressure in anesthetized rat. Cardioprotective effect of Pc. Cr was assessed in isoproterenol induced acute myocardial infarction (AMI) and left ventricular hypertrophy (LVH) in Sprague Dawley rats. In LVH, Pc. Cr exerted positive effects by decreasing angiotensin II & renin and increasing cGMP & nitric oxide (NO) with reduced cardiac fibrosis, necrosis and cardiac cell size. In AMI, Pc. Cr responded effectively by decreasing cardiac markers creatinine kinase (CK), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LD) in blood associated with less edema and necrosis. Presence of catechin, vinallic acid, P-coumeric acid and quercitin identified through HPLC support the effectiveness of Pc. Cr in hypertension, AMI and LVH. Pc. Cr showed no significant adverse effects in Sprague Dawley albino rats after acute & sub-acute treatment in histopathological investigation. Extract of Populus ciliata showed vasorelaxant, hypotensive and cardioprotective effect in Sprague Dawley albino rats and white albino rabbit by mediating EDRF and voltage dependent L-type CCB mechanism respectively.

Impact of vehicular emissions on anatomical and morphological characteristics of vascular plants: A comparative study

Abbottabad is a famous tourist destination due to its greenery and location. However, rapid increase in population and unplanned urbanization cause various environmental problems. Among different environmental stress, vehicular emission is the major issue for the survival and sustainability of plant species. This study aimed to investigate the effects of atmospheric pollution (caused by vehicular emission) on the anatomical, biochemical and morphological aspects of plant species present alongside the roads of Abbottabad, Pakistan. The plants were also collected from control sites (away from road-sites) for comparison. The results showed that various morphological characteristics of plant species including petiole length, vein-to-vein difference between leaves and length to breadth ratio of leaves were adversely affected by air pollution. The stomatal index varies in plant species because of variations in the numbers of epidermal cells. The air pollution tolerance index (APTI) of plant leaves from contaminated areas was reported to be higher as compared to control (non-contaminated) areas. Consequently, the findings from this study confirmed that plant species growing alongside of Abbottabad roads has greater tolerance than plant species growing in solitude areas away from road sites (control sites). Among different studied plants, Juglans regia, Morus nigra, Xanthium strumarium, Prunus armenica, Diospterus lotus and Populus ciliata have highest APTI and found to be more suitable for plantation in Abbottabad.

Populus ciliata conjugated of iron oxide nanoparticles and their potential antibacterial activities against human bacterial pathogens

Green synthesis is gaining huge significance because of its environmentally harmonious nature and low cost. This is an important technique to synthesize metal oxide nanoparticles. In the current study, iron oxide nanoparticles (Fe2O3-NPs) were formulated by using Populus ciliata leaf extract and ferrous sulphate (FeSO4.7H2O). These NPs were analyzed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Spectroscopy (FT-IR), and Energy Dispersive X-ray (EDX). The synthesized NPs were used against Gram positive and negative bacteria to find their bactericidal potential. These NPs were found active against Klebsiella pneumonia, Escherichia coli, Bacillus (B) lichenifermis and B. subtilis. B. licheniformis showed the highest antibacterial activity (zone of inhibition) up to 29.1±0.5 mm at 8 mg/mL concentration. This study concludes that Populus ciliata conjugated Iron oxides NPs could be used a potential antibacterial agent.

Comparative Study on Phytochemical Profile and Antioxidant Activity of an Epiphyte, Viscum album L. (White Berry Mistletoe), Derived from Different Host Trees.

The study aimed at evaluating the antioxidant profile of a medicinal epiphyte Viscum album L. harvested from three tree species, namely, Populus ciliata L, Ulmus villosa L., and Juglans regia L. The crude extracts were obtained with ethanol, methanol, and water and were evaluated for the total phenol content (TPC), total flavonoid content (TFC), and antioxidant activities using total reducing power (TRP), ferric reducing antioxidant power (FRAP), 1, 1-diphenyl 1-2-picryl-hydrazyl (DPPH), superoxide radical scavenging (SOR), and hydroxyl radical scavenging (•OH) assays. Our results showed that crude leaf extracts of plants harvested from the host Juglans regia L. exhibited higher yields of phytochemical constituents and noticeable antioxidative properties. The ethanolic leaf samples reported the highest phenols (13.46 ± 0.87 mg/g), flavonoids (2.38 ± 0.04 mg/g), FRAP (500.63 ± 12.58 μM Fe II/g DW), and DPPH (87.26% ± 0.30 mg/mL). Moreover, the highest values for TRP (4.24 ± 0.26 μg/mL), SOR (89.79% ± 0.73 mg/mL), and OH (67.16% ± 1.15 mg/mL) were obtained from aqueous leaf extracts. Further, Pearson correlation was used for quantifying the relationship between TPC, TFC, and antioxidant (FRAP, DPPH, SOR, OH) activities in Viscum album L. compared to their hosts. It was revealed that the epiphyte showed variation with the type of host plant and extracting solvent.

Green Synthesis of Nickel Oxide Nanoparticles using Populus ciliata Leaves Extract and their Potential Antibacterial Applications

ABSTRACT Green synthesis of nanoparticles has received a lot of attention from scientists globally because it is eco-friendly, relatively rapid, and a cost-effective method. This work presents a method for the green synthesis of nickel oxide nanoparticles (NiO-NPs) using leaf extracts of Populus ciliata as a reducing and stabilising agent. The synthesised NiO-NPs were characterised by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. It was found that the synthesised NiO-NPs shapes varied, were highly crystalline, and had a face-centred cubic geometry. The calculated crystallite size of the synthesised nanoparticles was 44 nm. Moreover, the antibacterial activity of the synthesised NiO-NPs was also conducted against Gram-positive bacteria (Bacillus subtilis, Bacillus licheniformis) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). Bacillus subtillus showed a maximum inhibition zone of 28.1±1.6 mm, whereas Klebsiella pneumonia showed a minimum inhibition zone of 9.2±0.5 mm. It was also found that the antibacterial activity increased with an increase in the concentration of NiO-NPs. Keywords: antibacterial activity, green synthesis, nanoparticles, NiO, Populus ciliata.

Assessment of Allelopathic Prospective of Agriculture Land Trees on Morphological and Yield Attributes of Wheat Varieties of Pakistan

The study was specifically designed to assess the allelopathic potential of some agriculture land related trees. The aqueous extracts of five different trees Corymbia citriodora, Juglans regia, Alianthus altissima, Populus ciliata and Melia azadrach were applied on two selected wheat cultivars (Triticum aestivumL.) CM 301 approved variety V1 and a local variety V2. Aqueous extracts of 20g/200ml ratio concentration were prepared separately. The allelopathic effects on morphological parameters of wheat as well as reduction or enhancement ratio of wheat yield were studied. Five Treatments (T0, T1, T2, T3, T4, T5) for both varieties were arranged in completely randomized design (CRD) with three replications each. The morphological parameters were measured after 40 days of sowing. Data were subjected to analysis of variance through (ANOVA) and least significant differences (LSD) were found by using software (Statistix 8.1). All treatments showed remarkable positive and negative effects on the parameters under investigation. Significant difference was observed by parameters such as number of tillers (0.0183), root length (0.018), flag leaf length (0.0191), flag leaf width (0.0153), numbers of awns (0.0164) and grains weight (0.0193). Some parameters showed non-significant difference like number of spikeslets (0.0930) and numbers of grains (0.1518). While numbers of spike (0.3754), spike length (0.6088) and plant height (0.4461) showed highly non-significant growth. The study concludes that Juglans regia and Melia azedarach showed growth enhancing effect while Populus ciliata and Alianthus altissima strongly inhibit the growth and yield of both wheat varieties.

Populus ciliata mediated synthesis of silver nanoparticles and their antibacterial activity.

Design and synthesis of bactericidal and fungicidal agents is very important to protect human beings from different diseases. Silver nanoparticles (AgNPs) possess good bactericidal properties. Synthesis of these nanoparticles (NPs) via green route is cost-effective and environmentally harmonious as compared to the chemical and physical approaches. In this work, AgNPs were synthesized through green synthesis method using Populus ciliata leaf extract. The synthesized AgNPs were characterized by x-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive x-ray (EDX) techniques. The XRD pattern depicted the characteristic Bragg's peaks of (111), (200), (220), and (311) planes which are the features of face centered cubic (FCC) geometry of the synthesized AgNPs. TEM micrographs revealed the spherical shaped particles having average size of 4 nm. The AgNPs showed inhibitory effects against selected gram positive (Staphylococcus epidermidis and Streptococcus pyogenes) and gram negative bacteria (Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas pseudoalcaligenes). The maximum zone of inhibition (26 mm) was observed for gram negative bacterium (Serratia marcescens) when 25 mg/ml solution of AgNPs was used and for similar concentration of these NPs, the maximum zone of inhibition (25 mm) was observed against gram positive bacteria (S. pyogenes). The results indicated good bactericidal potential of the synthesized AgNPs. RESEARCH HIGHLIGHTS: Populus ciliata leaf extract mediated synthesis of AgNPs. Transmission electron microscopy analysis revealed very small size of the synthesized AgNPs (4 nm). The synthesized AgNPs were found very effective against various bacterial pathogens.

Green synthesis of cobalt oxide nanoparticles for potential biological applications

Cobalt oxide nanoparticles (Co3O4-Nps) have many applications and now a days the green methods of synthesis of these NPs are preferred over other methods because of associated benefits. In this study, Co3O4-Nps were synthesized by using leaves extract of Populus ciliata (safaida) and cobalt nitrate hexa hydrate as a source of cobalt. The synthesized NPs were analyzed by different techniques such as fourier transform spectroscopy (FTIR), x-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Antibacterial activities of the synthesized Co3O4-Nps were evaluated against gram negative and gram positive bacteria and found active against Escherichia coli (E. coli), Klebseilla pneumonia (K. pneumonia), Bacillus subtillus (B.subtillus) and Bacillus lichenifermia (B. lichenifermia). The activity results were analyzed statistically by one-way ANOVA, with ‘Dunnett’s Multiple Comparison Test’. The maximum mean activity (21.8 ± 0.7) was found for B. subtilis and minimum mean activity (14.0 ± 0.6) was observed for E. coli.

Phytochemicals analysis and antibacterial activity of leaf extracts of Populus ciliata Wall. ex Royle

This research deals with the study of phytochemical analysis of methanol and chloroform extracts of Populus ciliata leaves and their further screening for antibacterial activity. The chemical profile of P. ciliata leaves revealed that both leaf extracts were rich in fatty acid esters, hydrocarbons and steroids. Methanol and chloroform extracts of P. ciliata leaves were observed with 44 and 47 major and minor phytocompounds, respectively. Major phytocompounds observed in the methanol extract were 9, 12, 15-octadecatrienoic acid, (Z, Z, Z)-(18.39%), l-(+)-ascorbic acid 2, 6-dihexadecanoate (13.95%), 9, 12-octadecadienoic acid (Z, Z)-(7.41%) and 3, 6-dimethoxy-2, 5-dinitrobenzaldehyde oxime (5.20%) whereas, chloroform extract was dominating with l-(+)-ascorbic acid 2, 6-dihexadecanoate (19.67%), 9, 12, 15-octadecatrienoic acid, (Z, Z, Z)-(18.91%), 9, 12-octadecadienoic acid (Z, Z)-(8.64%), ethyl 9, 12, 15-octadecatrienoate (7.80%) and hexadecanoic acid ethyl ester (5.05%). This study first time confirmed the antibacterial property of P. ciliata leaves with higher antibacterial activity of the methanol leaf extract against selected bacterial strains. Among all bacterial strains, methanol extract was found more effective against Gram negative bacteria (E. coli and P. aeruginosa; MIC-0.78 mg/ml) than Gram positive bacteria, whereas the chloroform extract showed maximum activity against E. coli (MIC-1.56 mg/ml).

Систематическое положение Populus ciliata Wall. ex Royle по результатам изучения морфологии побегов и петиолярной анатомии

Populus ciliate – ciliated poplar is distributed in the Himalayas at altitudes from 1300 to 3400 m above sea level, along river banks and wet slopes. The systematic position of the taxon remains unclear, although in most modern works it is attributed to the Tacamahaca section. The purpose of this study is to study the morphological features of crown shoots and the anatomical structure of petioles of Populus ciliata leaves to clarify its systematic position. Studies of the morphology of P. ciliata showed that it did not have specialized shortened shoots marking a section of balsamic poplars – diskoblasts. The most important signs of petiolar anatomy allowing the identification of poplar taxa at the section level are: the shape of the petiole cross section, the contours of its adaxial and abaxial sides, the shape of the rings of closed collateral bundles, the shape of the vascular system. A comparison of the obtained sections of P. ciliata with representatives of the Tacamahaca section indicates that the plants studied do not belong to balsamic poplars, since they differ in the absence of a groove pronounced on the adaxial side. The latter in the form of a small recess in the slice is fixed only at the place of its transition into the leaf blade. The contours of the abaxial and adaxial sides are round, the shape of the vascular system of the petiole is not highly arched like that of balsamic poplars, but linear, formed by elliptical rings of closed collateral bundles.

Flood history and river flow variability recorded in tree rings on the Dhur River, Bhutan

During the 2018 WorldDendro fieldweek in Bhutan, we examined the flood history of the Dhur River. Most villages are located along streams, so knowing the flood history of the area will enable managers to prepare for future events. We collected scarred partial cross sections from 29 trees along a two km stretch of the Dhur River, and two cores per tree from 29 other trees from six species (Populus ciliata, Picea spinulosa, Tsuga dumosa, Quercus semecarpifolia, Pinus wallichiana, and Rhododendron arboreum). We identified large flood events in 2009, 1989, and 1967 from at least two trees with flood scars or traumatic rings. Our flood-scar chronology extends to 1940 with five cross-sectioned trees, and back to 1904 with core evidence from two trees. The oldest flood scar occurred in 1967. The 2009 flood scar was recorded in most of our streamside samples and is the result of heavy precipitation from Cyclone Aila at the end of May 2009. Two other storms and proceeding flood events occurred in 1989 and 1967 according to additional scars detected in several samples. This work demonstrates the successful use of density fluctuations in Pinus along with scarring in multiple species to reconstruct past flood events and identifies the effects of Cyclone Aila, as an extreme event for this area, which was unprecedented for the past hundred years.

Populus ciliata leaves extract mediated synthesis of zinc oxide nanoparticles and investigation of their anti-bacterial activities

Recently, nanotechnology is making a valuable impact in every field of life. The recent progress and applications in the field of nanotechnology have extended the role of plants in synthesis of stable nanoparticles. The current study utilizes the aqueous extract of Populus ciliata (Wall. ex Royle) leaves to synthesize zinc oxide nanoparticles (ZnO-NPs) at mild temperature. The nanoparticles formation, their dispersion, shape and size were confirmed by various characterization techniques i.e. Fourier Transform Infra-Red (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), Tunneling Electron Microscopy (TEM), x-ray diffraction (XRD) and Energy Dispersive x-ray (EDX). In addition to this, the FTIR analysis indicated the presence of important functional groups. The as synthesized NPs have been used for antibacterial studies against human pathogenic bacteria; E. coli, P. aeruginosa, K. pneumoniae, S. aureus and S. pyogene. An increase in the zone of inhibition was observed with increasing ZnO-NPs, concentration.

Populus ciliata mediated synthesis of copper oxide nanoparticles for potential biological applications

The copper oxide nanoparticles (CuO NPs) have been successfully synthesized using the leaf extract of Populus ciliata (P. ciliata) as capping and stabilizing agent. The crystalline nature of CuO NPs was confirmed by x-ray diffraction (XRD) while the morphological study was conducted by performing Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The percent composition and purity was examined by using energy dispersive x-ray (EDX) while fourier transform infrared (FTIR) spectroscopy was used to study surface functional groups. The copper oxide nanoparticles (CuO NPs) were tested against Gram positive bacteria; Staphylococcus aureus (S. aureus) Staphylococcus pyogenes (S. aureus) and Gram negative bacteria; Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae) for its antibacterial activity. The antibacterial activity was increased with increasing concentration of the CuO NPs. A higher activity was found against Gram negative bacteria as compared to Gram positive bacteria.