Euonymus Japonicus Research Articles

Inversion and Effect Research on Dust Distribution of Urban Forests in Beijing

Urban forests affect the filtration and absorption of airborne particulate matter, which can minimize the harmful effects to human health caused by airborne particulate pollution. Evergreen plants in urban forests play a major role in absorbing dust and purifying the air, especially in winter. Studying the spatial distribution of leaf dust and exploring the dust retention effect of evergreen shrubs are important for scientifically guiding urban forest construction and improving the living environment of cities in winter. The purpose of this study was to establish a dust inversion model by correlation analysis of spectral reflectance and the amount of dust absorption (ADA) of vegetation, using Sentinel-2 satellite remote-sensing images to obtain the dust distribution of the evergreen vegetation (mainly Euonymus japonicus Thunb.) in the Beijing urban area, and to determine the effect of the spatial pattern of E. japonicus woodland on ADA intensity. The result showed that the red band and near-infrared band are most sensitive to dust. The normalized difference phenology index (NDPI) is more suitable for building an inversion model, where the determination coefficient (R2) of the inversion model constructed by the ratio of the NDPI (RNDPI) was 0.879. The inversion results show that the mean ADA in the enclosed area is smaller than that in semi-enclosed and open areas, and the regional distribution of high ADA in the urban area of Beijing was higher in the south with a tendency of the ADA to decrease from city center to the surrounding area. The size, shape, and percentage of landscape (PLAND) of E. japonicus woodland have a significant effect on ADA intensity. We found that, in the study area, when the PLAND of E. japonicus woodland is higher than 40%, its ADA intensity remains basically unchanged. When the vegetation coverage is fixed, the landscape shape index is negatively correlated with ADA intensity, and reduction of the overall shape complexity of forestland can enhance its dust retention effect and improve the air environment of the surrounding areas. The results of this study can be used as a reference for urban planners and landscape architects when building urban forests, providing a scientific basis for controlling and reducing air particulate pollution in Beijing’s winter and improving the living environment.

Tracing chronological shifts in farmland demarcation trees in southwestern Japan: implications from species distribution patterns, folk nomenclature, and multiple usage

BackgroundUnderstanding the history of anthropogenic vegetation is often difficult due to the lack of tangible historical evidence. In this study, we examined chronological changes of farmland demarcation trees planted on alluvial plains along the Hijikawa River in southwestern Japan based on species distribution patterns, folk nomenclature, and multiple usage of the trees.MethodsThe species composition of demarcation trees was investigated at 47 sites in 13 villages. We performed hierarchical clustering using Bray–Curtis measures to detect groups of similar tree composition and permutational multivariate analysis of variance to test whether differences in species composition correspond to village units. To better understand the traditional knowledge of demarcation trees, we conducted interviews with 53 farmers, most of whom were over 60 years old.ResultsClustering resulted in six tree composition groups. The group characterized by the most frequently planted species, Chaenomeles speciosa, dominated around lower reach villages. The group characterized by Euonymus japonicus dominated around middle reach villages, and that characterized by Salix pierotii was mainly located around upper reach villages. Chaenomeles speciosa was always identified with the standard Japanese name boke or similar names. Euonymus japonicus and several other species were also called boke by many farmers. Several elderly farmers stated that C. speciosa was pervasive in upper and middle reach villages in their youth, suggesting the prototypical use of C. speciosa in the study area. In addition, some minor species were likely to have been left after commercial crop production or subsistence use between the late nineteenth and mid-twentieth centuries, including Morus sp. and Celtis sinensis for sericulture, Salix koriyanagi for fiber production, and Gardenia jasminoides for food coloration. The name kōshin bana recorded for E. japonicus suggests that the species’ use originated from the folk faiths Kōshin-shinkō and/or Shōmen-Kongō.ConclusionsThe composition of demarcation trees in the region has not been stable over time, but instead changed to reflect the local livelihood, industry, and faiths. Despite the lack of tangible historical evidence, the spatial distribution patterns, folk nomenclature, and traditional knowledge of plants can provide clues to trace the chronological background of ecotopes in anthropogenic landscapes.

Variability in morphological traits of seedlings from five Euonymus japonicus cultivars

In this study, we investigated the variability in morphological traits of seedlings from five Euonymus japonicus cultivars. We measured seedling heights, root collar diameters, leaf lengths and widths, root lengths, root numbers, and twig numbers of 60 seedlings from each cultivar. The E. japonicus cultivars Variegate and Green Rocket had the highest (95.8%) and lowest (70.3%) rooting percentages, respectively. With the exception of root lengths (p > 0.05), all morphological characteristics significantly differed among all cultivars (p < 0.05). In particular, the cultivar Green Rocket performed better than all other cultivars, with greater seedling heights and root collar diameters. These data warrant further studies for quantifying differences in traits among these cultivars.

Size fractions of dust and amount of associated metals on leaf surface and inner wax of 15 plant species at Beijing roadside

To provide more insight into the removal ability of urban air dust and associated metals by plant leaves, and thus guide urban green planning to improve air quality, 15 plant species leaves collected from Beijing roadside were analyzed for size fractions of leaf surface dust (SD) and inner wax dust (WD). Seven associated metals Cd, Cr, Cu, Fe, Mn, Pb and Zn were also measured. Metal Accumulation Index (MAI) was calculated for different species leaves at various dust sizes and soluble forms, respectively. Cluster analysis was used for the plant species and correlations between dust and metal concentrations and for inter-metal concentrations were calculated for both surface and inner wax dust. Mean leaf total dust TD (SD + WD), SD and WD were measured as 1159, 817 and 342 mg m−2, respectively, with the highest values observed all in Euonymus japonicus. Most species leaves collected larger ratios of SD than WD except Salix babylonica and Robinia pseudoacacia. While SD was presented at all particle size fractions for all plants, nearly all species leaves collected higher proportions of WD >10 µm. Mean metal levels of leaf TD of all species ranged from high to low as Fe > Cr > Zn > Pb > Cu > Mn > Cd, but with different orders for individual species. Metals were observed in all sizes of SD/WD, although the size distributions were various for certain metals. Intercorrelations of metal concentrations in leaf SD/WD were positively significant except Pb, which may have different emission sources. Species Prunus cerasifera f. atropurpurea, Syringa oblata, Malus micromalu, Koelreuteria paniculata and Robinia pseudoacacia may possess better overall metal collection ability due to their relatively higher MAI values, but species Euonymus japonicus, Malus micromalu, Ligustrum x vicaryi and Koelreuteria paniculata were identified as the best choices in removing air dust based on cluster analysis and suggested to be planted at heavy trafficked road site for air quality improvement.

Detection and characterisation of phytoplasma strains associated with field bindweed witches’ broom disease in Iran

During 2013–2015 surveys in Fars, Lorestan and Yazd provinces (Iran), a field bindweed witches’ broom (FBWB) disease was observed. The main symptoms were reduction of leaves size, yellowing, internode shortening, witches’ broom and stunting. The agent of FBWB was dodder transmitted to periwinkle plants inducing phytoplasma-type symptoms. Amplifications of nearly 1.8 and 1.2 kbp were, respectively, obtained from 15 symptomatic bindweed plants and 28 symptomatic dodder-inoculated periwinkles. Virtual RFLP analyses showed that the phytoplasma detected belonged to 16SrXII-A subgroup, and it was the same in all the samples examined; phylogenetic analyses confirmed it as a ‘Candidatus Phytoplasma solani’-related strain. This is the first report of 16SrXII-A phytoplasmas presence in bindweed plants showing witches’ broom symptoms in Fars, Lorestan and Yazd provinces. As a perennial widespread weed, it may act as a 16SrXII-A phytoplasma source for alfalfa, grapevine, Sophora alopecuroides, tomato, hemp and Japanese spindle reported diseases in these Iranian provinces.

Effects of saline irrigation management on growth of aEuonymushedge in Mediterranean urban spaces

Selecting salt-tolerant crops is vital under salinity, but salt tolerance must also be considered in the light of irrigation management. The aim of this study was to assess how the saline irrigation volume affects both the growth of Euonymus japonicus 'Marieke' plants forming a hedge and soil moisture and salinity. Irrigation was controlled with Hydra Probe II placed at 15 and 30 cm depth. The treatments were: i) irrigation with fresh water and irrigation volume based on the recharge of the 100% of consumed water (control); ii) saline irrigation (3 dS m-1) and irrigation volume as in control (S(100)); iii) saline irrigation and 75% of the control (S(75)); iv) saline irrigation and 125% of the control (S(125)). The VWC in the control at 15 cm depth was 27.41%, which was increased by S100 and was reduced by S(75). At 30 cm depth, the highest VWC was in S(125). This treatment reduced pore water EC (ECpw) at 15 cm depth compared with the rest of the saline treatments, while at 30 cm depth S(125) produced a value of ECpw close to that of control (3.32 dS m-1). The S(100) reduced the aerial volume and plant height, while S(75) led to plants with the lowest growth. The S(125) slowed down the decreasing growth caused by S(75). Saline treatments promoted the presence of t roots. S(125) increased total root length, being roots 0.5-2 mm diameter the most promoted. So, saline water can be used successfully for the irrigation of urban green spaces using soil moisture and EC sensors, which help to improve water use efficiency and to maintain growth.

Management of powdery mildew of Euonymus japonicus in Kashmir Valley

Powdery mildew of Euonymus japonicus was managed by chemicals, bioagents and pruning based integrated disease management (IDM) approaches. Among fungicides flusilazole significantly reduced disease intensity by 8.30 and 1.36% as compared to 58.80 and 18.05% in check on leaves and twigs respectively, while, potassium bicarbonate was less effective than the fungicides. Among the biocontrol agents tested in vivo, Ampelomyces quisqualis was significantly superior in reducing the PDI by 34.71 and 9.72% on leaves and twigs as compared to 58.16 and 17.10% on check. Trichoderma viride was the least effective in reducing the PDI by only 40.53 and 12.17 on leaves and twigs, respectively. Pruning of twigs 6 cm below diseased area proved significantly superior to other pruning levels in checking the disease by 18.79 and 5.08% on leaves and twigs, respectively. In case of IDM approach, alternate sprays of flusilazole (0.02%) and A. quisqualis culture filtrate (50%) along with pruning of twigs (6 cm below diseased area) proved as the most effective integrated disease management strategy by exhibiting 2.33 and 0.16% disease intensity on leaves and twigs compared to 56.40 and 17.15% in the check.

Natural dyes as sensitizers for dye-sensitized solar cells

The dye-sensitized solar cells (DSSCs) have been fabricated by using a series of natural dyes extracted from euonymus japonicus and purple plants. The optical characteristics and chemical structure of dyes were investigated by UV-visible spectroscopy and Fourier infrared spectroscopy. It is found that the absorption of sunlight and bonding performance to TiO2electrode of dyes had significantly effects on the conversion efficiency of solar cells. The results show the cells using blueberry as sensitizer achieved best conversion efficiency of 0.218%, attributed to its strong absorption and excellent bonding to the TiO2electrode, correspondingly, the short-circuit photocurrent density ([Formula: see text] and open-circuit voltage ([Formula: see text] were 1.3[Formula: see text]mA/cm2and 430[Formula: see text]mV, respectively.

Perpetuation and host range of Oidium euonymi-japonici causing powdery mildew of Euonymus japonicus in Kashmir valley, India

The pathogen Oidium euonymi-japonici (anamorph) causing powdery mildew of Euonymus japonicus in Kashmir valley overwintered asexually as mycelium on intact infected twigs which started producing conidia in the 4th week of February and continued till ending October during both the years of study 2013 and 2014. The pathogen ceased to produce conidia from the 1st week of November to 3rd week of February, 2013–2014 and 2014–2015. On intact-overwintered infected twigs, maximum conidial production and viability was observed during 1st week of April and 1st week of August in both the years. However, no conidial formation was observed on the twigs, kept 10 cm deep in the soil. The cross inoculation study revealed that inoculum from Euonymus japonicus successfully infected all the other Euonymus genotypes tested but failed to infect the weeds and other test hosts and vice versa.

The complete chloroplast genome sequence of the plant Euonymus fortunei (Celastraceae)

Chloroplast (cp) genome sequences become a useful popular tool for population and phylogeny in recent reports. Here, the complete cp genome of the Euonymus fortunei has been reconstructed from the whole-genome Illumina sequencing data. The circular genome is 157,639 bp in size, and comprises a pair of inverted repeat (IR) regions of 26,668 bp each, a large single copy (LSC) region of 85,956 bp and a small single copy (SSC) region of 18,347 bp. The total GC content is 37.2%, while the corresponding values of the LSC, SSC, and IR region are 35.1%, 31.7%, and 42.7%, respectively. The cp genome contains 126 genes, including 89 protein-coding genes, eight ribosomal RNA genes, and 29 transfer RNA genes and one pseudogene. The maximum-likelihood phylogenetic analysis showed a strong sister relationship with Euonymus japonicus in Celastraceae. Our findings provide a foundation for further investigation of cp genome evolution in E. fortunei and other higher plants.

Histological and cytological studies of plant infection by Erysiphe euonymi-japonici.

Powdery mildew caused by Erysiphe euonymi-japonici (Eej) is an increasingly serious fungal disease on Euonymus japonicus that is an important ornamental plant. However, little is currently known about infection and pathogenesis of Eej on E. japonicus. Here, we report plant infection by Eej at the histological and cytological levels. Eej caused severe disease symptoms with white and snow-like colonies on leaf surfaces of E. japonicus. Microscopic observations were conducted continuously to define infection process of Eej on E. japonicus. Eej conidia germinated to produce appressorial germ tubes on leaf surfaces and formed irregular haustoria in plant epidermal cells at 6h post-inoculation (hpi) and 12hpi, respectively. After uptaking nutrients from host cells by haustoria, Eej formed numerous hyphae and extensive colonization on leaf surfaces at 96hpi and finally produced abundant conidiophores and new conidia on leaf surfaces at 168hpi. In addition, there was consistently a single nucleus in different Eej infection structures and haustorial development could be divided into three major stages, including formation of penetration peg, formation of haustorial neck and initial haustorium, and maturation of haustorium. These results provide useful information for further determination of Eej pathogenesis and finally controlling the disease.

Facile preparation of biomass-derived bifunctional electrocatalysts for oxygen reduction and evolution reactions

The development of inexpensive and efficient bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is still remained a challenge in wide range of renewable energy technologies. Herein, biomass-derived nitrogen self-doped porous carbon nanosheets (NPCNS) are produced by a facile and green pyrolysis of Euonymus japonicus leaves at controlled temperature and then the nitric acid pickling was carried out to remove the excess metal ingredients. The obtained NPCNS exhibits a hierarchically porous distribution, high BET surface area and uniform nitrogen doping. Electrochemical measurements show that the NPCNS possess a high electrocatalytic activity for both ORR and OER. Among these NPCNS catalysts, the sample carbonized at 900 °C (NPCNS-900) with the highest concentration of pyridinic nitrogen shows the best ORR and OER activity. According to our DFT calculations, the high content of pyridinic nitrogen with the moderate O and OH adsorption energies among the three types of nitrogen should be the critical factor for the efficient catalytic performance of NPCNS-900 toward ORR and OER. This work demonstrates that the facile prepared NPCNS-900 is a potential candidate material with excellent performance in electrocatalytic applications such as fuel cells or metal-air batteries.

The Complete Chloroplast Genome of Catha edulis: A Comparative Analysis of Genome Features with Related Species.

Qat (Catha edulis, Celastraceae) is a woody evergreen species with great economic and cultural importance. It is cultivated for its stimulant alkaloids cathine and cathinone in East Africa and southwest Arabia. However, genome information, especially DNA sequence resources, for C. edulis are limited, hindering studies regarding interspecific and intraspecific relationships. Herein, the complete chloroplast (cp) genome of Catha edulis is reported. This genome is 157,960 bp in length with 37% GC content and is structurally arranged into two 26,577 bp inverted repeats and two single-copy areas. The size of the small single-copy and the large single-copy regions were 18,491 bp and 86,315 bp, respectively. The C. edulis cp genome consists of 129 coding genes including 37 transfer RNA (tRNA) genes, 8 ribosomal RNA (rRNA) genes, and 84 protein coding genes. For those genes, 112 are single copy genes and 17 genes are duplicated in two inverted regions with seven tRNAs, four rRNAs, and six protein coding genes. The phylogenetic relationships resolved from the cp genome of qat and 32 other species confirms the monophyly of Celastraceae. The cp genomes of C. edulis, Euonymus japonicus and seven Celastraceae species lack the rps16 intron, which indicates an intron loss took place among an ancestor of this family. The cp genome of C. edulis provides a highly valuable genetic resource for further phylogenomic research, barcoding and cp transformation in Celastraceae.

Capacity of six shrub species to retain atmospheric particulates with different diameters.

Garden plants can absorb and retain atmospheric particles and are important for remediating environmental pollution. In this study, the dust retention characteristics of six typical shrub species were measured in the greenbelt of a road in the Chengyang District of Qingdao, China, and the maximum capacity for dust retention of each species was determined. The different diameters and areas occupied by particulate matter (PM) were analyzed on the leaf surfaces of the plants. Based on the results for the six shrub species, the rank order of average content of dust retention per unit leaf area was Euonymus japonicus > Pyracantha fortuneana > Ligustrum vicaryi > Amygdalus triloba > Ligustrum sinense > Forsythia suspensa, whereas the rank order of average content per unit volume was E. japonicus > A. triloba > P. fortuneana > L. vicaryi > L. sinense > F. suspensa. The maximum content of dust retention per unit leaf area was reached in approximately 24days. Plants retained atmospheric PM primarily on the upper leaf surfaces. The primary portion of particles on the leaves was PM10 (over 80%), and PM2.5 was the principal component of PM10. Leaf surface structure significantly affected the abilities of plants to retain PM, and the plants with a thick wax layer or large and dense stomata adsorbed more PM, such as E. japonicus. This study provides a scientific basis for the capacity of landscape plants to retain different diameter particulates.

Retrieving vegetation canopy water content from hyperspectral thermal measurements

The retrieval of vegetation canopy water content using thermal hyperspectral (TIR, 8–14μm) measurements is investigated in this study. Vegetation water content indicators such as fuel moisture content (FMC, %, mass-based) and equivalent water thickness (EWT, gcm−2, area based) play significant roles in plant physiology, as well as in the modelling of fire risk and behavior, particularly in forests. Although retrieval of these parameters, in particular EWT, has been demonstrated from optical and TIR measurements, to our knowledge their prediction at canopy level in the thermal part of the electromagnetic spectrum has not yet been investigated. Therefore, the application of hyperspectral TIR data for predicting FMC and EWT parameters at canopy level is explored here. The emissivity of spectral data in the TIR region is measured for four species (Azalea japonica, Buxus sempervirens, Euonymus japonicus, and Ficus benjamina) under controlled laboratory conditions, using a portable MIDAC Fourier transform infrared spectrometer. EWT, FMC, and their corresponding canopy emissivity measurements are assessed by destructive sampling of the leaves. Leaf area, as well as fresh and dry mass of the harvested leaves, is determined for all four species. Partial least square regression and artificial neural networks, using various spectral subsets, are used to predict the two variables of interest. Higher estimation accuracies have been obtained for both FMC and EWT at canopy level using artificial neural networks. Unexpectedly, the FMC at canopy level, as a mass-based variable, more accurately retrieved using either method. This is contrary to previous findings using multispectral and hyperspectral data. Our results suggest that plant mass may play a greater role in determining spectral emissivity than plant area does.

Influence of rainfall duration and intensity on particulate matter removal from plant leaves

Rainfall influences removal of airborne particulate matter (PM) from leaf surfaces through a process called wash off resulting in throughfall that carries PM to the ground. The present study examined the effects of rainfall characteristics on PM wash-off mass and rate from the foliage of four broadleaf species, to investigate retention of PM pollution. In a controlled rainfall simulation experiment, rainfall intensity was set to 15, 30, and 50mmh−1, and sampling intervals for the three rainfall intensities were divided into 10, 5, and 3min, respectively. Of the plants examined, the evergreen shrub Euonymus japonicus had the greatest surface PM accumulation before rainfall (165μgcm−2), maximum wash-off during the first 2.5mm of rain (30μgcm−2), and maximum surface PM retention after rainfall (24μgcm−2). Fitting observations with the Box Lucas regression model, cumulative PM wash-off rates increased with cumulative rainfall amount, until the curves tended to become steady after rain exceeded 12.5mm. Wash off removed 51 to 70% of surface PM accumulation. As rainfall intensity increased, the duration of PM wash-off decreased, and wash-off rates were highest during the first rainfall interval. However, there was no significant difference between PM wash-off rates for rainfall intensities of 30 and 50mmh−1 in each rainfall interval. In addition, rain did not remove all PM completely, and PM retention following rainfall differed with rainfall intensity, except for Populus tomentosa.

Particulate matter and heavy metal deposition on the leaves of Euonymus japonicus during the East Asian monsoon in Beijing, China.

Plants can be effectively used as bio-monitors of environmental pollution. However, how the particulate matter (PM) and heavy metal retention ability of plants changes in different areas with human disturbance along with monsoon has not yet been investigated in urban ecosystems. In this study, we measured the amount of PM and heavy metals such as Ni, Cr, Cu, Pb, and Zn accumulated by the leaves of Euonymus japonicus during the East Asian monsoon from different functional units in Beijing, China. A rinse-and-weigh method developed in our laboratory was used to determine the mass of the PM, and electro-thermal atomic absorption spectrometry was used for heavy metal analysis. We found that the types of functional units had little influence, whereas the monsoon had a significant effect on the deposition of PM: northwest areas during the monsoon had the lowest effect (with 0.005, 0.453, 0.643, and 1.569 g/m2 fine, coarse, large, and total PM, respectively), and the southeast areas during the monsoon had the highest effect (0.015, 2.687, 1.941, and 4.228 g/m2 for fine, coarse, large, and total PM, respectively). Notable, we found considerable variations in heavy metal accumulation across the functional units analyzed, that is, the accumulation level was higher in communities than in parks (P < 0.0001 for all heavy metals). Moreover, a positive relationship was found between PM retention and heavy metal accumulation by the leaves of E. japonicus. Taken together, our results suggested that the PM and heavy metal retention ability of E. japonicus was sensitive to human disturbance and monsoon in Beijing. Since E. japonicus is a widely distributed tree and has the ability of to purify the atmosphere, it is an ideal plant for mitigating urban environmental pollution.

The prioritisation of a short list of alien plants for risk analysis within the framework of the Regulation (EU) No. 1143/2014

Thirty-seven alien plant species, pre-identified by horizon scanning exercises were prioritised for pest risk analysis (PRA) using a modified version of the EPPO Prioritisation Process designed to be compliant with the EU Regulation 1143/2014. In Stage 1, species were categorised into one of four lists – a Residual List, EU List of Minor Concern, EU Observation List and the EU List of Invasive Alien Plants. Only those species included in the latter proceeded to the risk management stage where their priority for PRA was assessed. Due to medium or high spread potential coupled with high impacts twenty-two species were included in the EU List of Invasive Alien Plants and proceeded to Stage 2. Four species (Ambrosia trifida, Egeria densa, Fallopia baldschuanica and Oxalis pes-caprae) were assigned to the EU Observation List due to moderate or low impacts. Albizia lebbeck, Clematis terniflora, Euonymus japonicus, Lonicera morrowii, Prunus campanulata and Rubus rosifolius were assigned to the residual list due to a current lack of information on impacts. Similarly, Cornus sericea and Hydrilla verticillata were assigned to the Residual List due to unclear taxonomy and uncertainty in native status, respectively. Chromolaena odorata, Cryptostegia grandiflora and Sphagneticola trilobata were assigned to the Residual List as it is unlikely they will establish in the Union under current climatic conditions. In the risk management stage, Euonymus fortunei, Ligustrum sinense and Lonicera maackii were considered a low priority for PRA as they do not exhibit invasive tendencies despite being widely cultivated in the EU over several decades. Nineteen species were identified as having a high priority for a PRA (Acacia dealbata, Ambrosia confertiflora, Andropogon virginicus, Cardiospermum grandiflorum, Celastrus orbiculatus, Cinnamomum camphora, Cortaderia jubata, Ehrharta calycina, Gymnocoronis spilanthoides, Hakea sericea, Humulus scandens, Hygrophila polysperma, Lespedeza cuneata, Lygodium japonicum, Pennisetum setaceum, Prosopis juliflora, Sapium sebiferum, Pistia stratiotes and Salvinia molesta).

Research on the Dust-Capturing Capacities of Environmental Friendly Materials Based on the Typical Garden Trees and the Morphological Structure of Leaves in Suzhou

Air pollution is one of the most serious environment pollution. 8 typical landscape plants, in Suzhou City, were selected to quantitative study their dust-capturing capacities, and the morphological traits of their leaves were observed under a SEM (scanning electron microscope). The paper showed that there were great differences in the dust-capturing capability of garden trees, and the dust-capturing capacities of garden trees in different seasons were in the order of May &gt; August &gt; November; the leaves of Cinnamomum camphora (L.) Pres, Camellia japonica L. and Euonymus japonicus Thunb. var. Ovatus Aureus had smooth surfaces or tubercles, whose dust-capturing capacities were poor, while the leaf of Loropetalum chinense(R.Br.) Oliv.Var. rubrum Yieh had many wrinkled form of cuticle, deep grooves, trichomes and high stomata desity which were favor of dust-retained, thus its dust- capturing capacity was stronger. The results can be seen as a possibility of select suitable species for urban environment.

Bacillus velezensis strain HYEB5-6 as a potential biocontrol agent against anthracnose on Euonymus japonicus

ABSTRACTAnthracnose is a foliar disease of the Euonymus shrub caused by Colletotrichum gloeosporioides. In this study, the bacterium HYEB5-6 was isolated from inside one-year-old branches of healthy Euonymus japonicus and showed significant antifungal activities against various phytopathogenic fungi, including C. gloeosporioides s.s. HYCG2-3, in dual culture experiments. The HYEB5-6 isolate significantly decreased lesion diameter and disease index caused by C. gloeosporioides inoculation on detached leaves of E. japonicus. The effects of HYEB5-6 metabolites on the invading structure of the fungus were investigated. Bacterial metabolites inhibited conidial germination, the growth of the germ tube and appressorium formation, possibly through protease and glucanase of HYEB5-6 by managing the mycelial cell wall. The HYEB5-6 isolate also produced a massive biofilm, which might facilitate leaf colonisation. These results indicate that HYEB5-6 has the potential for use as a biological control agent against C. gloeosporioides. The HYEB5-6 isolate was identified as Bacillus velezensis based on its biochemical characteristics and its 16S rRNA gene sequence.