Rhododendron Research Articles

Evaluation of Synergy Between Lignite and Carbonized Biomass During Co-Combustion

Abstract Synergy often occurs between coal and biomass during co-utilization, and the combustion reactivity and combustion properties of coal are affected mainly due to high volatile matter in biomass. However, it is not clear that a synergistic interaction will be encountered if coal is processed with biochar that contains a limited amount of volatiles due to charring process. In this article, the existence of synergy was questioned based on the thermal analysis data obtained from the co-combustion of several biochars and lignite. The biochars produced at 400 °C from lignocellulosic biomasses such as Fraxinus (FR—ash tree), Populus hybrids (PO—hybrid poplar), and Rhododendron (RH) were blended with Turkish lignite (Adıyaman-Golbasi) to form blends that contain 5–15% biochars. These blends were burned in a thermogravimetric analyzer, and the combustion characteristics of the blends were evaluated, considering the criteria that include the reactivity and combustion performance indices including ignition index, comprehensive combustion index, burnout performance index, combustion stability indices, and rate and intensity index. Also, synergy indices such as synergy indicator, synergy factor, and interaction coefficient were calculated to identify the presence and intensity of synergy. It was concluded that depending on the type of biochar and the addition rate, changes occurred in the combustion properties of the coal, which can sometimes be considered as additive behavior and sometimes as a synergistic interaction. The presence of 5% or 10% PO biochar in the blends resulted in very obvious synergies in combustion characteristics according to all eight criteria considered.

Effects of vegetation indices, auxin, and biostimulator treatments on the rooting of Rhododendron pulchrum cuttings

The objective of our study was to develop a protocol enabling the use of vegetation indices to evaluate the rooting of Rhododendron pulchrum cuttings . Six root growth parameters were recorded after those cuttings were exposed to rooting media for 47 days. Among plants with different of soil-plant analysis development (SPAD) and normalized difference vegetation index (NDVI) values, those with higher values exhibited significantly higher values for the root number, root length, and root dry weight, suggesting that reflectance indices were useful in measuring the root growth parameters of R. pulchrum cuttings. Another aim of this work was to study the effects of a plant growth regulator (PGR) and biostimulant on rooting for cutting propagation. Treatments with indole-3-butyric acid (IBA) of 2000 mg×L -1 alone and combined with 1-naphthaleneacetic acid (NAA; 2000 mg×L -1 ), salicylic acid (SA; 10 -4 M), and thiamine (TA; 800 mg L - 1 ) were applied to cuttings of R. pulchrum . The same observations on six different rooting parameters were recorded and analyzed after cuttings were exposed to rooting media for 99 days for the auxin test, and 62 days for the SA and TA tests. Compared to NAA, IBA enhanced root growth and development as determined by increases in all parameters, and therefore it was used thereafter. Successful results for the root number and root dry weight were achieved using cuttings of R. pulchrum with a combination of IBA and SA. In addition, the mix of IBA and TA resulted in higher root numbers. These combined treatments are recommended for establishing stem cuttings for raising R. pulchrum plants in the nursery.

Effects of Pretreatment Outside of Torrefaction Range on Combustion Characteristics of Chars From Lignocellulosic Biomass

Lignocellulosic woody biomasses such as rhododendron (RD), ash tree (AT), and hybrid poplar (HP) were heated under N2 at 200 °C and 400 °C, which are regarded as outside the range of efficient torrefaction temperatures. Also, several Turkish brown coals were carbonized at 750 °C for comparison. The obtained biochars/chars were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and thermal analysis. Combustion reactivity of the raw samples and the chars was estimated using the burning profiles. Burning kinetics was established by the Borchardt and Daniels (B&D) kinetic analysis method that was based on the evaluation of the differential scanning calorimetry (DSC) data. Ignition index (Ci), burnout index (Cb), comprehensive combustibility index (S), and burning stability index (DW) were considered to evaluate the combustion performance. It was concluded that although treatment at 200 °C did not lead to considerable changes on the biomass structure, the combustion performance of the treated biomass became highly improved in comparison with the raw biomass. However, treatment at 400 °C led to serious variations in the biomass structure mainly due to reduction in O content and volatiles so that the fuel properties and the burning characteristics were affected, and the combustion performance was negatively influenced.

Synergistic Interactions During Cocombustion of Lignite, Biomass, and Their Chars

Woody biomasses such as ash tree (AT), hybrid poplar (HP), and rhododendron (RD) were subjected to torrefaction and carbonization at temperatures of 200 °C and 400 °C. Likewise, several lignite samples were carbonized at 750 °C. Various binary fuel blends such as raw lignite/raw biomass, raw lignite/biochar, lignitic char/raw biomass, and lignitic char/biochar were prepared where the fraction of biomass or biochar was 10 wt% in the blends. The cocombustion characteristics of these blends were investigated through a thermal analysis method from the synergetic point of view considering the fuel properties and the combustion performance. Some parameters relevant to the combustion reactivity such as ignition point, maximum rate, peak temperature, and burnout temperature were commented to figure out whether synergistic interaction or additive behavior governs the combustion characteristics of the blends. Also, the combustion performance indices such as ignition index (Ci), burnout index (Cb), comprehensive combustibility index (S), and the burning stability index (DW) were estimated. It was concluded that the combinations of the additive behavior and the synergistic interactions governs the cocombustion process, and the kind of the fuels and their thermal history determine the reactivity and the interactions during cocombustion.

Evaluation on the suspended solids and heavy metals removal mechanisms in bioretention systems

Application of bioretention systems in Korea is highly considered due to its minimal space requirements, appropriateness as small landscape areas and good pollutant removal and peak hydraulic flow reduction efficiency. In this study, the efficiency of two lab-scale bioretention types having different physical properties, media configuration and planted with different shrubs and perennials was investigated in reducing heavy metal pollutants in stormwater runoff. Type A bioretention systems were planted with shrubs whereas type B were planted with perennials. Chrysanthemum zawadskii var. latilobum (A-CL) and Aquilegia flabellata var. pumila (A-AP) respectively were planted in each type A bioretention reactors while Rhododendron indicum linnaeus (B-RL) and Spiraea japonica (B-SJ), respectively were planted in each type B bioretention reactors. Results revealed that the four lab-scale bioretention reactors significantly reduced the influent total suspended load by about 89 to 94% (p<0.01). Type B-RL and B-SJ reactors reduced soluble Cr, Cu, Zn, and Pb by 28 to 45% that were 15 to 35% greater than the soluble metal reduction of type A-CL and A-AP reactors, respectively. Among the pollutants, total Cr attained the greatest discharged fraction of 0.52-0.81. Excluding the effect of soil media, total Pb attained the greatest retention fraction in the bioretention systems amounting to 0.15-0.34. Considering the least discharge fraction of heavy metal in the bioretention system, it was observed that the bioretention systems achieved effectual reduction in terms of total Cu, Zn and Pb. These findings were associated with the poor adsorption capacity of the soil used in each bioretention system. The results of this study may be used for estimating the maintenance requirements of bioretention systems.

Synergistic Investigation for Co-Combustion of Biochars and Lignite—Thermogravimetric Analysis Approach

Abstract This paper addresses whether synergistic interaction or additive behavior govern the co-combustion characteristics of lignite and biochars produced from hybrid poplar (HP), ash tree (AT), and rhododendron (RH). The biochars were blended with lignite and the burning behavior was investigated by thermal analysis. Upon carbonization, fundamental change occurred in the burning mechanisms of biomass from homogeneous to heterogeneous reactions. Blending the lignite with biochars led to improvement in the calorific value and reductions in the ash yield. Carbonization limited the high reactivity of biomass, and the reactivities of biochars became closer to the lignite's reactivity, consequently they burned in accord without segregation.

Rhododendrons and Travels: a Forest of Colours to Open the World's Eyes

Montagnards, voyageurs, poetes et philosophes citent le rhododendron, plante symbolique de la montagne, de l'Himalaya aux Pyrenees. Les photographes de la nature montrent l'eblouissement de couleurs que sont leurs fleurs, symboles de beaute qui pourtant ont joue un role devastateur dans l'histoire de la Grece. Plante double qui eblouit de sa beaute ou dans les buissons enchevetres de laquelle on peut se perdre, le rhododendron joue aussi un role dans la cosmogonie tibetaine. Cet article voudrait montrer comment les textes de voyageurs, de montagnards, de philosophes ou de poetes font de cette plante mythique pour les montagnards, un guide vers la conscience de notre relation a la nature.

Anti-wrinkle and Skin-whitening Efficacy of Rhododendron micranthum Methanol Extract

Anti-wrinkle and Skin-whitening Efficacy of Rhododendron micranthum Methanol Extract

The features of leaf anatomical structure of some Rhododendron species from section Ponticum

The article represents a comparative anatomical analysis of leaves of Rhododendron makinoi, R. degronianum, R. callimorphum and R. brachycarpum. It was shown that leaves of R. makinoi have most pronounced xerophytic features. R. degronianum and R. makinoi are similar by most of morphometric characteristics, while R. callimorphum and R. brachycarpum are well distinguishable. However, some quantitative parameters of the leaf with statistically significant difference in R. makinoi and R. degronianum have been detected and can be used as additional criteria for their taxonomic distinguishing. In general, investigated species differ mostly by type and number of trichomes. The presence of small idioblasts in the studied species was ascertained.

Frost covered rhododendron bush, in Dorking, Surrey

Frost covered rhododendron bush, in Dorking, Surrey

Infestation of Micromycetes on the Flowers and Seeds of Rhododendron sp.

Infestation of Micromycetes on the Flowers and Seeds of Rhododendron sp.

Phenological Events along the Elevation Gradient and Effect of Climate Change on Rhododendron arboreum Sm. in Kumaun Himalaya

Phenological events of rhododendron ( Rhododendron arboreum Sm.) were monitored along elevation gradients in distinct ecological settings. The observations were carried out between 1500 and 2500 m elevation in Central Himalaya. The phenological events, i.e. bud formation, bud bursting, leafing, flowering, fruit formation and seed formation were recorded. Phenological duration and synchrony of all these phenophases were determined within site and along the elevation gradient in each study site. Our observations showed high synchrony throughout the elevation gradient, especially for peak flowering. Temperature, rainfall, age of the observed trees and site characteristics were related to initial and peak flowering dates. The circumference varied from 35.0 ± 2.73 to 140.0 ± 2.88 cm; similarly, height varied from 5.0 ± 1.02 to 16.5 v 1.41 m. All the phenological events began early at low elevation and were delayed at higher elevation. R. arboreum had a sharp flowering peak from January to March. Wet season flowering was rare, and seed formation occurred in summer. The climatic conditions affected the phenological characters of R. arboreum .

The responses of early foliar litter humification to reduced snow cover during winter in an alpine forest

Ni, X., Yang, W., Li, H., Xu, L., He, J., Tan, B. and Wu, F. 2014. The responses of early foliar litter humification to reduced snow cover during winter in an alpine forest. Can. J. Soil Sci. 94: 453-461. Snow cover can be reduced by ongoing winter warming in alpine biomes, affecting foliar litter humification, but few reports are available. To quantitatively clarify how early foliar litter humification responds to reduced snow cover in winter, a field litterbag experiment was conducted in an alpine forest in southwestern China. Mass losses, ΔlogK, E4/E6, degrees of humification and humification rates of six typical local foliar litters were investigated at the snow formation, snow cover and snow melt stage under snowpack levels differing in depth (deep snowpack, medium snowpack, thin snowpack, no snowpack) from November 2012 to April 2013. The results indicated that 14-15% of willow (Salix paraplesia), 8-9% of fir (Abies faxoniana), 6-7% of birch (Betula albo-sinensis), 5-8% of cypress (Sabina saltuaria), larch (Larix mastersiana) and azalea (Rhododendron lapponicum) foliar litter was humified, which was about 50% of what decomposed during the first winter. Moreover, the early humification of foliar litter (except for fir and birch) responded positively to the reduced snow cover, but mass loss exhibited negative responses. Such results suggest that reduced snow cover in winter would increase soil carbon or other material sequestration in the scenario of climate change.

Germplasm resource base for rhododendron horticulture: status, problems and countermeasures

杜鹃花种质资源是决定未来杜鹃花产业发展潜力的根本。作者通过探讨杜鹃花种质资源保育利用现状与存在的问题, 试图为我国杜鹃花产业的健康与可持续发展提供一些新的思路。目前全球杜鹃花产业的种质资源利用率为12.0–15.0%, 我国仅为8.7–12.2%, 仍具有巨大的利用潜力。现今利用的杜鹃花种类以映山红亚属（Subgenus Tsutsusi）、羊踯躅亚属（Subgenus Therorhodion）等中小型半常绿或落叶类群为主。作者根据多年的观察, 指出了我国的一些适合用于未来品种选育的原始种类。目前, 我国杜鹃花产业主要面临的问题是对种质资源的价值认识不足、研发平台建设滞后、缺乏持续提供新品种及其配套技术的能力等。为此, 作者提出了如下对策： （1）正确认识杜鹃花的资源价值, 加强杜鹃花知识的传播, 在种质资源型产业的构建、改造、运作等过程中充分权衡和监督种质资源基础设计的合理性与可持续性; （2）构建杜鹃花种质资源联盟, 建立3–5个以杜鹃花为主体的自然保护区; （3）提升杜鹃花产业的研发与创新能力。

Atrioventriküler Tam Blok ve Akselere Nodal Ritmin Nadir Bir Nedeni; Deli Bal Zehirlenmesi

An unusual type of food poisoning, mad honey intoxication, can be observed in the Black Sea region of  Turkey and various  other  parts of the world.  It can occur after ingestion of grayanotoxin-contaminated honey produced from the nectar of Rhododendron ponticum  and other plant species, chiefly of the Ericaceae and Sapindaceae families. Mad honey  intoxication can result in severe cardiac complications, such as complete atrioventricular block. The diagnosis is generally reached on the basis of the patient's history of honey intake.  In this report, we describe the case of a patient who had mad honey related complete atrioventricular block and accelerate nodal rhythm.

Antibacterial and cytotoxic activities of high altitude essential oils from Nepalese Himalaya

Essential oils of Rhododendron anthopogon, Artemisia vulgaris,  Zanthoxylum armatum,Acrous calamus, Cinnamomum glaucescens, Nardostachys grandiflora and Abies spectabilis are studied for antibacterial and cytotoxic activities, and are evaluated with standard antibiotics for the synergistic potentiality against human pathogenic bacteriaStaphylococcus aureus, Escherichia coli and Klebsilla pneumonia. Antibacterial activity was performed by cup-plate method and cytotoxicity was evaluated by brine shrimp lethality test. Essential oils of C. glaucescens, R. anthopogon and Z. armatum were found to have higher antibacterial activity against E. coli, S. aureus and K. pneumonia, respectively. The best synergism of R. anthopogon oil and erythromycin was found in 20,000 µg/20 µl. Similarly, synergism of essential oil was done in four different concentration (20000/20, 10000/20, 5000/20, 2500/20, 1000/20, 500/20, 250/20 and 125 µg/20 µl). The best result was shown in 125 µg/20 µl against E. coli.   Key words: High altitude medicinal plants, essential oils, human pathogen, bacteria, cytotoxicity.

Simultaneous estimation of three triterpenoids‑ursolic acid, b‑sitosterol and lupeol from flowers, leaves and formulations of Rhododendron arboreum Smith. using validated HPTLC method

Background: This paper enfolds a rapid and sensitive high‑performance thin‑layer chromatographic (HPTLC) method for the simultaneous estimation of three triterpenoids namely ursolic acid, β‑sitosterol and lupeol from the leaves, flowers and herbal formulations of Rhododendron arboreum Smith., an ethnomedicinal Himalayan tree. All the three phytoconstituents have high therapeutic value. Aims and Objectives: The main aim is to separate, resolve and simultaneously quantitate the three markers‑ursolic acid, β‑sitosterol and lupeol from R. arboreum using normal phase HPTLC. Materials and Methods: Separation was performed on TLC aluminium plates precoated with silica 60 F254 followed by detection of ursolic acid, β‑sitosterol and lupeol carried out by derivatizing the plate with 10% methanolic sulphuric acid reagent followed by heating at 110°C for 7 min. Camag TLC scanner 4 equipped with winCATS software was used for densitrometric scanning at 366 nm. The proposed method was further validated in terms of linearity, precision, accuracy and sensitivity as per the International Conference on Harmonisation (ICH) guidelines. Results: A good linear relationship was obtained for the calibration plots with r2 = 0.999, 0.993 and 0.995 for ursolic acid, β‑sitosterol and lupeol, respectively. Accuracy of the method was checked by recovery study conducted at three different levels with the average recovery between 95% and 98% for all the three markers. Conclusion: The developed method can be used for the assessment of the quality of botanicals in terms of bioactive content. Key words: Ethnomedicinal, Rhododendron arboreum, simultaeneous estimation, triterpenoids

Testate Amoebae Communities in the Rhizosphere of Rhododendron ponticum (Ericaceae) in an Evergreen Broadleaf Forest in Southern Spain

Testate amoebae (TA) are an important part of soil microbial communities and in certain ecosystems they may represent a substantial proportion of total microbial biomass. Their distribution and abundance is driven by various abiotic factors (e.g. pH, organic matter, soil moisture, soil/water chemistry) but comparatively less is known about the role of biotic interactions. TA often co-occur with Ericaceae, a ubiquitous plant family inhabiting acidic soils with poor nutrient status. Ericaceae can significantly change soil properties through production of recalcitrant litter and possibly also due to root exudates and activities of root-inhabiting fungi; this may result in profound modifications of microbial communities. A recent study from northwest England shows that the invasive ericaceous shrub Rhododendron ponticum may significantly modify communities of soil TA. Here, we investigate the effect of pH, organic matter, soil moisture and R. ponticum presence on TA communities within the native range of the ericaceous shrub at two sites in south Spain and compare our results with the previous study from NW England. At the Spanish sites, organic matter content, R. ponticum presence and pH affected occurrence and abundance of several TA species; R. ponticum presence and organic matter content were highly correlated and explained most of the observed variability in TA communities (= the effect of the R. ponticum rhizosphere). R. ponticum rhizosphere affected especially TA with relatively large tests, i.e. Cyclopyxis eurystoma, Phryganella acropodi a and Trigonopyxis arcula . Interestingly, T. arcula was also positively associated with R. ponticum in the previously studied British sites. The rhizosphere of the ericaceous shrub appears to have a positive effect on testate amoebae taxon richness at the two studied autochthonous Spanish sites but may reduce taxon richness in the sites in Britain where R. ponticum is an introduced species. Such possible positive/negative effects of native/invasive species, as well as other plant guilds, on TA communities clearly deserve further investigation.

Determination of benzylacetone in the rhododendron by HPLC

Objective To establish a HPLC method for determination of benzylacetone in the rhododendron.Methods The HPLC analysis was carried out on Luna C18(250 mm×4.6 mm,5 μm) at 30℃temperature.The mobile phase was acetonitrile-water (64 ∶ 36),the flow rate was 1 ml/min,and the detection wavelength was 220 nm.Results The linear range of benzylacetone was 17.08～170.8 μg/ml (R=0.9998),the average recovery of this method was 99.81％,and the RSD was 1.46％.Conclusion The method is convenient,quickly and accurate,can be used for the quality control of rhododendron oil and their preparations. Key words: Benzylacetone ;  Rhododendron ;  HPLC ;

Resynthesis of Ericoid Mycorrhizae in Formosan Rhododendron (Rhododendron formosanum Hemsl.) with an Endophytic Cryptosporiopsis Species

Formosan rhododendron (Rhododendron formosanum Hemsl.) is an indigenous species of the Ericales in Taiwan. The Rf32 fungal strain was isolated from the roots of wild Formosan rhododendron and identified as an endophytic species of Cryptosporiopsis based on its morphological characteristics. This identification was further confirmed by an internal transcribed spacer sequence analysis. This species is a new addition to the fungal flora of Taiwan. In an ericoid-mycorrhizal resynthesis experiment, Rf32-inoculated Formosan rhododendron seedlings exhibited vigorous growth, and the root association showed hyphal complexes in cortical cells. The results demonstrated that Formosan rhododendron can form ericoid mycorrhizae in vitro with Cryptosporiopsis sp. Rf32.