Small Shrubs Research Articles

Is the removal of aboveground shrub biomass an effective technique to restore a shrub‐encroached grassland?

Encroachment of woody plants into grasslands is a global phenomenon that has substantial impacts on pastoral productivity and ecosystem services. Over the past half century, pastoralists and land management agencies have explored various options to control woody plants in order to improve ecosystem services in shrub‐encroached grasslands. We examined the effectiveness of controlling the encroachment of the shrub Caragana microphylla into grassland in Inner Mongolia, China. We cut and removed all of the aboveground biomass from 450 shrubs, predicting that the effectiveness of this technique to control shrubs would depend on shrub morphology. Specifically, we expected that larger shrubs with more biomass would be more difficult to kill by cutting than smaller shrubs. A year after treatment, we found that cutting killed only 11% of the 450 treated shrubs, and of these, three‐quarters of the locations that they occupied reverted to grasses and one‐quarter to bare soil. Shrubs that survived the cutting treatment produced more stems and leaf biomass, and therefore had a greater leaf to stem ratio. Shrubs that died after cutting had a lower crown area and basal area, and less stem biomass than shrubs that resprouted within 12 months of cutting. There were no effects of shrub height on the fate of treated shrubs. Cutting had no effect on understory plant cover or richness, but reproductive plants were taller under shrubs that were not cut. Overall, our study showed that removing aboveground shrub biomass by cutting is an ineffective technique for “restoring” the original grassland community unless shrubs are very small. Strategic targeting of small shrubs would be a more effective technique for controlling the spread of C. microphylla in the long term.

First Report of Powdery Mildew of Excoecaria cochinchinensis Caused by Pseudoidium neolycopersici in China

Excoecaria cochinchinensis Lour., a small evergreen shrub in the family Euphorbiaceae, is usually grown as a native ornamental plant in South China. In April 2019, severe powdery mildew infection was observed on E. cochinchinensis in a garden (23.9°N, 113.23°E) in Guangzhou, China. Nearly 60% of the Excoecaria plants were infected, and the foliage of infected plants turned yellow and necrotic, followed by rapid defoliation. Voucher specimens were deposited in the Herbarium of Mycology of Guangdong Institute of Traditional Chinese Medicine under accession number HMGDTCM18. White to gray rounded irregular patches, consisting of abundant mycelia and conidia of the fungus, were found on both leaf surfaces and green stems. Hyphae were septate, branched, and with moderately lobed appressoria. Conidia were solitary, borne on top of conidiophores, and were ellipsoidal, hyaline, 38 to 48 × 13 to 17 μm (mean 42 ± 3 × 15 ± 1 μm, n = 50), containing no distinct fibrosin bodies. Conidiophores were erect, unbranched, consisted of three cells, and 84 to 117 μm long (mean 106 ± 7 μm, n = 50). Chasmothecia were not observed on sample plants. The pathogenicity of this fungus was confirmed by gently pressing infected leaves onto healthy leaves and stems of three healthy seedlings in separate pots, and two noninoculated seedlings were used as a control. After maintaining at 25°C in a greenhouse for 10 days, similar disease symptoms were observed in the inoculated plants, whereas no symptoms developed on control plants. Molecular identification was conducted by extracting genomic DNA from conidia washed from infected leaves and using a Fungal DNA Kit (Omega Bio-tek, Guangzhou, China). The rDNA internal transcribed spacer region was amplified using primers ITS1/ITS4 (Glass and Donaldson 1995). The obtained sequence (GenBank accession no. MK811439) analysis by BLASTN search showed>99% similarity with Pseudoidium neolycopersici (GenBank accession nos. LC009912.1 and AB032484.1). On the basis of the morphological and molecular analyses, the fungus was identified as P. neolycopersici (Kiss et al. 2001). This pathogen has only been reported on Codiaeum variegatum, a euphorbiaceous host (Liu et al. 2015). To our knowledge, this is the first report of this fungus infecting Excoecaria. In addition, P. neolycopersici has been reported on tomato, papaya, and Physalis pubescens in China. Therefore, powdery mildew infection on E. cochinchinensis not only poses a potential threat to health and beauty of this ornamental plant but may also serve as a reservoir of the pathogen that could allow spread to other economically important hosts.

A topical ointment formulation containing leaves extract of Aegialitis rotundifolia Roxb., accelerates excision, incision and burn wound healing in rats

Abstract Background Aegialitis rotundifolia Roxb., is a small mangrove tree or shrub used traditionally as a potent cure for pain arising from various injuries. Presently, there is a single scientific report on the wound healing property of this mangrove species which has been performed in-vitro but there is no in vivo scientific evidence of the wound healing properties. Further, few reports have claimed that reduction of pain could accelerate wound healing process and thus, the present work deals with the development of a topical ointment formulation incorporated with Aegialitis rotundifolia Roxb., ethanolic leaves extract (ARELE) which could potentially accelerate healing of excision, incision and burn wound models in Wistar rats. Methods Topical ointment containing ARELE was first tested for their stability (90 days) and possible dermal toxicity using standard procedures. In the excision wound model, parameters such as in-vivo antioxidant, acute inflammatory marker (myeloperoxidase), wound microbial load, connective tissue parameters, and histopathology of healed skin were performed. Incision and burn (thermal and chemical) wounds were conducted following the standard methods. Results The ointment formulations were found to be stable and dermatologically non-toxic. In the excision wound model, a significant increase in percent wound contraction was observed for ARELE ointment treated groups which are substantiated by strong in-vivo antioxidant activity, increased collagen formation, almost normal skin histology, and reduced myeloperoxidase and microbial colonies. Strong wound breaking strength was observed in incision wound repair and a significant increase in percent wound closure in both thermal and chemical burn wound model was recorded for ARELE ointment treated groups. Conclusion Therefore, the topical application of ARELE ointment formulations showed remarkable excision, incision and burn wound healing in Wistar rats thus showing its potential as a promising wound healing agent.

Bioactive Compounds and Health Benefits of Artemisia Species

Artemisia L. is a genus of small herbs and shrubs found in northern temperate regions. It belongs to the important family Asteraceae, one of the most numerous plant groupings, which comprises about 1000 genera and over 20000 species. Artemisia has a broad spectrum of bioactivity, owing to the presence of several active ingredients or secondary metabolites, which work through various modes of action. It has widespread pharmacological activities and has been used as traditional medicine since ancient times as an anthelmintic, antispasmodic, antirheumatic, and antibacterial agent and for the treatment of malaria, hepatitis, cancer, inflammation, and menstrual-related disorders. This review comprises the updated information about the ethnomedical uses and health benefits of various Artemisia spp. and general information about bioactive compounds and free radicals.

Propagation of Scabiosa hymettia (Boiss. & Spruner) by stem cuttings

Scabiosa hymettia Boiss. & Spruner (syn. Lomelosia hymettia, fam. Dipsacaceae) is an endemic xerophyte of central and southern Greece, and of the northern Aegean region. It is a small shrub of the macchia zone, very attractive from May to mid-July when it bears blue-purple flowers on elongated flower peduncles. In the present study its vegetative propagation by stem cuttings was investigated, in order to introduce the species as an ornamental plant in urban and suburban areas and historical Mediterranean landscapes. Cuttings derived from the apical part of shoots, 15 cm long, bearing two to four lateral shoots, were collected from a wild population at mount Parnitha (prefecture of Attiki, Greece), in spring (March), summer (August), autumn (October) and winter (January) for two consecutive years. The base of the cuttings was immersed either in powder indole-3-butyric acid (IBA) for herbaceous/softwood or for hardwood cuttings, or in IBA ethanol-water (1:1, v/v) solutions, at four different concentrations: 0 (control), 1000, 2000 and 3000 mg L(‑1), for two dipping times, 1 or 5 min, and were put for rooting on a mix of 1 peat:1 perlite (v/v) in a mist system for two weeks and then on a heated-glasshouse bench for further six weeks. Almost all cuttings (92.5-100%) collected in autumn and winter rooted when treated with powder IBA for hardwood cuttings, or with 1000 mg L(‑1) IBA ethanol-water solution for 1 min, while the controls rooted at 45-65%. In spring and particularly in summer, cuttings rooted at lower rates compared to autumn and winter. Best response in spring was achieved with the use of powder IBA for hardwood cuttings (50% rooting), or with 5 min dipping in IBA solutions (50-67.5% rooting). In summer highest rooting was induced either with powder IBA for hardwood cuttings (45.0%) or with 1000 mg L(‑1) IBA for 1 min dipping time (37.5%).

Responses of different herb life-history groups to a dominant shrub species along a dune stabilization gradient

Shrubs play a pivotal role in reversing desertification and in promoting ecological rehabilitation in severe environments. However, how the interactions between shrubs and their understorey species change during restoration remains unclear. Here, we report the results of an observational study conducted in the Mu Us Desert of northern China. This study explored how dune stabilization and the size of individual shrubs affect shrub–herb interactions. In particular, we aimed to determine how different life-history groups and performance indicators (e.g., biomass and richness) of subordinate species respond to shrub–herb interactions during dune stabilization. The shrub Artemisia ordosica had positive effects on understorey species in this dune system. The ability of the shrub to promote the growth of understorey species increased with dune stabilization, but decreased from small to large shrubs. This effect was due to an increase in the relative abundance and biomass of perennials and their higher sensitivity to the positive effects of the shrubs. In contrast, the ability of shrubs to improve the richness of understorey species decreased with dune stabilization, but increased from small to large shrubs. This effect occurred because perennials suffered high strain during recruitment in disturbed open patches of the semi-fixed dunes, particularly below small shrubs. Our results support the theory claiming that communities are sets of hidden interaction groups that have contrasting responses (neutral for annuals, but facilitative for perennials) to dominant neighbors in a single community, depending on their functional strategies. Furthermore, our study highlights the high efficiency of A. ordosica in facilitating ecological restoration of dry and disturbed sandy communities.

Leaf functional trait variation in a humid temperate forest, and relationships with juvenile tree light requirements.

The species-rich arborescent assemblages of humid tropical forests encompass much of the known range of the leaf economics spectrum, often including >20-fold variation in leaf lifespan. This suite of traits underpins a life-history continuum from fast-growing pioneers to slow-growing shade-tolerant species. Less is known about the range of leaf traits in humid temperate forests, and there are conflicting reports about relationships of these traits with the light requirements of temperate evergreen angiosperms. Here I quantify the range of leaf functional traits in a New Zealand temperate evergreen forest, and relationships of these traits with light requirements of juvenile trees and shrubs. Foliage turnover of saplings of 19 evergreen angiosperms growing beneath gaps (12–29% canopy openness) and in understories (1.2–2.9%) was measured over 12 months. Dry mass per area (LMA), dry matter content, thickness, density and nitrogen content (N) of leaves were also measured. Species minimum light requirements were indexed as the 10th percentile of the distribution of saplings in relation to canopy openness. Interspecific variation of leaf lifespan was ∼6-fold in gaps (0.6 to 3.8 yrs), and ∼11-fold in the understorey (0.7 to 7.7 yrs). Six small tree and shrub species are effectively leaf-exchangers, with leaf lifespans of c.1 year in gaps—albeit usually longer in the shade. Interspecific variation in other leaf traits was 2.5 to 4-fold. Lifespans and LMA of both sun and shade leaves were negatively correlated with species light requirements i.e., positively correlated with shade tolerance. However, light environment (gap vs shade) explained about the same amount of variation in LMA as species’ identity did. Species light requirements were not significantly correlated with leaf N, dry matter content, density or thickness—except for a marginally significant correlation with dry matter content of shade leaves. Species light requirements were thus less consistently related to leaf structural traits than appears to be the case in humid tropical forests. Whereas the wide interspecific variation in leaf economic traits of tropical rainforest species outweighs plastic response to light availability, temperate evergreen woody angiosperms appear to occupy a narrower range of the leaf economic spectrum. Standardization of the light environments in which LMA is measured is vital in comparative studies of humid temperate forest evergreens, because of countergradient responses of this trait to light, and because of the relative magnitudes of plastic and interspecific variation in LMA in these forests.

Exploring Dittrichia viscosa (L.) Greuter phytochemical diversity to explain its antimicrobial, nematicidal and insecticidal activity

Dittrichia viscosa is a perennial small shrub belonging to the Compositae family (Asteraceae) widespread in the Mediterranean basin. This plant has been extensively used in traditional medicine since the Roman times as reported by the Roman Naturalist Gaius Plinius Secundus. Nowadays, many studies about chemical composition and biological activity of D. viscosa are available. Chemical analyses of plant extracts revealed the presence of several metabolites belonging to different classes of natural products such as sesquiterpenes, flavonoids and caffeic acids. In addition, the essential oil of D. viscosa is rich in volatile short chain metabolites with aldehydes, alcohols and esters functional groups, as well as long chain fatty acids esters and alkyls. Some of these compounds are known for their biological activities against a wide range of micro- and macroorganisms. Scientific evidence reported that derivates of caffeic acids and flavonoids were the compounds mainly related to inhibition of bacterial and fungal growth, whereas sesquiterpene lactones and eudesmane sesquiterpenes were most active against nematodes, mites, insects and parasitic plants. In this paper, information about the phytochemical composition and the biological activity of D. viscosa against bacteria, fungi, nematodes, mites, insect and parasitic plants have been summarized.

Pharmacognostical study of Ochrosia elliptica Labill. (Apocynaceae)

Ochrosia elliptica Labill. is a small shrub belonging to family Apocynaceae and well-known as a promising anti-cancer agent. Botanical study of the plant was done for the young and old stems, stem bark, and leaves. Laticiferous tubes with yellowish brown content, isodiametric stone cells (sclereids), sclerenchyma (rod-like) and calcium oxalate clusters are the main diagnostic elements observed in this plant. Furthermore, DNA fingerprinting was done using rapid amplified (RAPD) and inter simple sequence repeat (ISSR) techniques with the identification of a total of 30 RAPD markers and 17 ISSR markers. Carbohydrates, sterols, catechol tannins, flavonoids and alkaloids were present in all organs under investigation. This study could be valuable for quality control of the plant.

Giant leucaena (Leucaena leucocephala subsp. glabrata): a versatile tree-legume for sustainable agroforestry

Leucaena leucocephala (leucaena) is one of the 22 Leucaena species that originated in Central America. There are two major subspecies of leucaena, L. leucocephala subsp. glabrata (giant leucaena) and L. leucocephala subsp. leucocephala (common leucaena). Giant leucaena is a medium size fast-growing tree important for agroforestry while common leucaena is a small bushy shrub that is considered to be an invasive weed. Giant leucaena can be grown as a woody tree of up to ~ 20 m in height or maintained as a bushy fodder legume by repeated harvest of its foliage several times a year. Giant leucaena grown for fodder can produce forage dry mater yield of up to 34 Mg ha−1 year−1. High forage yield together with high protein content makes leucaena an ideal fodder legume for the tropical and subtropical regions of the world. Although mimosine present in the leucaena foliage has toxicity, it should not be a big concern because ruminants can be successfully inoculated with the mimosine-metabolizing rumen bacterium Synergistis jonesii. Alternatively, mimosine present in the leucaena foliage can be removed easily and inexpensively through simple processing. Giant leucaena cultivars are generally free from diseases and are highly tolerant to drought. Although infestation by psyllids may be a problem, a number of psyllid-resistant cultivars of giant leucaena have been developed through interspecies hybridization. The wood of giant leucaena can be used for timber, paper pulp, or biofuel production. Leucaena foliage and wood may serve as raw materials for development of new industry for production of phytochemicals such as mimosine, tannins and anthocyanins, wood products, and high-protein animal feed for farm animals in the future.

Competition suppresses shrubs during early, but not late, stages of arid grassland–shrubland state transition

Abstract Transitions from grass to woody plant dominance, widely reported in arid systems, are typically attributed to changes in disturbance regimes in combination with abiotic feedbacks, whereas biotic mechanisms such as competition and facilitation are often overlooked. Yet, research in semi‐arid and subhumid savannas indicates that biotic interactions are important drivers in systems at risk for state transition. We sought to bridge this divide by experimentally manipulating grass‐on‐shrub and shrub‐on‐shrub interactions in early and late stages of grassland–shrubland state transition, respectively, and to assess the extent to which these interactions might influence arid land state transition dynamics. Target Prosopis glandulosa shrubs had surrounding grasses or conspecific neighbours left intact or killed with foliar herbicide, and metrics of plant performance were monitored over multiple years for shrubs with and without grass or shrub neighbours. Productivity of small shrubs was enhanced by grass removal in years with above‐average precipitation, a result not evident in larger shrubs or during dry years. Proxy evidence based on nearest neighbour metrics suggested shrub–shrub competition was at play, but our experimental manipulations revealed no such influence. Competition from grasses appears to attenuate the rate at which shrubs achieve the size necessary to modify the physical environment in self‐reinforcing ways, but only during the early stages of shrub encroachment. Our results further suggest that at late stages of grassland‐to‐shrubland state transitions, shrub–shrub competition will not slow the rate of shrub expansion, and suggest that maximum shrub cover is regulated by something other than density‐dependent mechanisms. We conclude that grass effects on shrubs should be included in assessments of desert grassland state transition probabilities and rates, and that desertification models in arid ecosystems that traditionally focus on disturbance and abiotic feedbacks should be broadened to incorporate spatial and temporal variations in competitive effects. A plain language summary is available for this article.

Histopathological Effects of Potassium Bromate on Liver Male Rat's and Possible Protective Role of Ruta chalepensis L. (Rutacae) Oil Extract

Potassium bromate (KBrO3) is an oxidizing agent that has been used as a food additive, mainly in the bread-making process. Ruta chalepensis L. (Family-Rutaceae) is a small shrub, native to the Mediterranean Basin. The present study aimed to investigate the protective and curative effects of R. chalepensis oil extract against KBrO3 toxicity on liver of male rats. Fifty male albino rats were divided into five groups. The first group served as a control group. The second group was administered Rue at an oral daily dose of 0.5 g/Animal for four weeks. The third group received KBrO3 100 mg/kg/b. w. for four weeks. The fourth group (protective group) was initially administered Rue alone for 2 weeks and followed by KBrO3 in association with Rue for 2 weeks. The fifth group (therapeutic group) was first given KBrO3 alone for 2 weeks and was then administered Rue in association with KBrO3 for 2 weeks. At the end of 2nd and 4th weeks of treatment, the liver tissues were dissected out for histopathological studies. Histopathological sections of rats administered with Rue showed the same histological observations as in the liver of control animals. KBrO3 treated rats exhibited marked congestion and dilatation of the blood vessels, the central veins and the portal veins. Additionally, marked infiltrative inflammatory cells were revealed. The occurrence of the cellular necrobiotic lesions and nuclei in these necrotic cells showed pyknosis. They also, showed cellular atrophied and hyaline degeneration of the cytoplasm. Vacuoles of different shapes and sizes were developed in the hepatocytes. Blood vessels being thick walled and fibrotic encircled by an inflammatory area rich in leucocytes. The protective and therapeutic groups showed marked hepatoprotective activity and better improvement than that noticed in the group which was given KBrO3 only. It may be concluded from the results that the hepatotoxic effect of KBrO3 and the ameliorative effect of Rue an effective when administrated as protective and therapeutic measures. Keywords: Rat, Liver, Potassium Bromate, Ruta chalepensis, Histopathology.

Evaluation of the schistosomicidal, antioxidant and anti-inflammatory activities of the ethyl acetate fraction from Ozoroa pulcherrima Schweinf. Roots on Schistosoma mansoni-induced liver pathology in mice and its phytochemical characterization

Ethnopharmacological relevanceOzoroa pulcherrima Schweinf. (syn.: Heeria pulcherrrima Schweinf.) is a small shrub belonging to the family Anacardiaceae. In Africa, the stem and the leaves are used to treat dystocia, hyperthermia, and conjunctivitis, while the root is used to treat dysmenorrhea and intestinal helminthiasis. Aim of the studyThe aim of this study was to assess the schistosomicidal, antioxidant and anti-inflammatory effects of the ethyl acetate fraction from O. pulcherrima roots methanolic extract (EAOp) on S. mansoni- induced liver pathology in mice. Additionally, its phytochemical composition was elucidated. Material and methodsThe phytochemical characterization of EAOp was carried out by High-Performance Liquid Chromatography-Mass spectrometry (HPLC-MS). Total phenolic and flavonoid contents were also quantified in the fraction. S. mansoni-infected mice received daily and per os, for 28 days, EAOp at 200 or 400 mg/kg, starting from the 36th day post-infection. Praziquantel was used as reference drug. Uninfected-untreated, uninfected-treated and infected-untreated mice served as controls. At the 65th day post-infection mice were sacrificed and parasitological burden monitored. Transaminases, total bilirubin, and total proteins levels were determined in the plasma. Malondialdehyde (MDA), nitrites, superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) levels were measured in the liver as biomarkers of the oxidative stress. Liver histology and morphometric analysis of granulomas were also conducted. ResultsThe HPLC-MS analysis data of EAOp revealed the presence of four triterpenes namely oleaterminaloic acid, hydroxyoleanolic acid, moronic acid, and oleanolic acid; a flavonoid dipentoxybenzoic acid and two alkaloids. Its total phenolic content was 76.46 ± 0.01 mg GAE/g and total flavonoid content 6.26 ± 0.31 mg rutin equivalent/g. The reductions of worm burden (48.89 and 75.56%), fecal egg count (77.76 and 69.52%) and egg load in the liver (65.33 and 77.18%) and intestine (78.06 and 84.63%) were significant after EAOp treatment. EAOp at all doses significantly (p < 0.001) reversed the increasing transaminases activities and total bilirubin level induced by the infection. A normalization of total proteins concentration was also recorded. Treatment of S. mansoni-infected mice with EAOp at 200 or 400 mg/kg resulted in a significant reduction (p < 0.001) of MDA concentration by 73.20% and 67.78% respectively. The level of nitrites which was reduced by the infection significantly increased after the treatment. EAOp significantly increased by 4.67 and 5.69-fold the CAT activity and by 126.67% the GSH level. Histologically, a significant reduction of the number (66.39 and 57.82%) and the volume (52.25 and 34.81%) of liver inflammatory granulomas was recorded after EAOp treatment at all doses. ConclusionsThese results suggest that the liver pathology in S. mansoni infection is improved by EAOp which disclosed good schistosomicidal, antioxidant and anti-inflammatory activities. Its effects on the liver dysfunction and the hepatic oxidative stress were comparable to that of praziquantel. These findings justified the traditional use of O. pulcherrima for the treatment of intestinal helminthiasis. This fraction can be considered as a promising source for schistosomicidal agents.

Analysis of Using Dense Image Matching Techniques to Study the Process of Secondary Succession in Non-Forest Natura 2000 Habitats

Secondary succession is considered a threat to non-forest Natura 2000 habitats. Currently available data and techniques such as airborne laser scanning (ALS) data processing can be used to study this process. Thanks to these techniques, information about the spatial extent and the height of research objects—trees and shrubs—can be obtained. However, only archival aerial photographs can be used to conduct analyses of the stage of succession process that took place in the 1960s or 1970s. On their basis, the extent of trees and shrubs can be determined using photointerpretation, but height information requires stereoscopic measurements. State-of-the-art dense image matching (DIM) algorithms provide the ability to automate this process and create digital surface models (DSMs) that are much more detailed than ones obtained using image matching techniques developed a dozen years ago. This research was part of the HabitARS project on the Ostoja Olsztyńsko-Mirowska Natura 2000 protected site (PLH240015). The source data included archival aerial photographs (analogue and digital) acquired from various phenological periods from 1971–2015, ALS data from 2016, and data from botanical campaigns. First, using the DIM algorithms, point clouds were generated and converted to DSMs. Heights interpolated from the DSMs were compared with stereoscopic measurements (1971–2012) and ALS data (2016). Then, the effectiveness of tree and shrub detection was analysed, considering the relationship between the date and the parameters of aerial images acquisition and DIM effects. The results showed that DIM can be used successfully in tree and shrub detection and monitoring, but the source images must meet certain conditions related to their quality. Based on the extensive material analysed, the detection of small trees and shrubs in aerial photographs must have a scale greater than 1:13,000 or a 25 cm GSD (Ground Sample Distance) at most, an image acquisition date from June–September (the period of full foliage in Poland), and good radiometric quality.

Hygienic coatings with bioactive nano-additives from Senna occidentalis-mediated green synthesis

Nowadays urban populations spend 90% of their time in buildings where microbial growth lead to hazardous environments which produce health problems characterized by irritation of the respiratory tract, infections, allergies and asthma. Some research lines seek to obtain antimicrobial materials to prevent such health problems. Green synthesis of different nanoparticles was carried out to explore their antimicrobial potential. Solutions of silver, copper, cerium, lanthanum and zinc salts were used as source of metal ions for the synthesis process. Aqueous plant extract from Senna occidentalis, a small shrub, was used, for the first time, as reducing and stabilizing agent to obtain additives to bioactive coatings. The stable synthesis products were evaluated by UV–vis spectroscopy and their antimicrobial properties were assessed. Other characterizations by transmission electron microscopy and Fourier transformed infrared spectroscopy were also performed. Silver and copper nanoparticles were stable over time. However, only silver nanoparticles showed antibacterial and antifungal activity and were used for obtaining antimicrobial waterborne acrylic paints. The formulation with 25 mg/100 g resulted in efficient inhibition of the fungal and bacterial biofilm.

Ants as Predators of Diorhabda elongata (Chrysomelidae), a Biological Control Agent of Saltcedar (Tamarix spp.), in Texas

Four species of leaf beetles, Diorhabda spp, (Chrysomelidae), were introduced for biological control of saltcedar, Tamarix spp., an invasive small tree or shrub, in the US. In Texas, three species established at some sites but failed to establish or initially established but did not persist at other sites. Diorhabda larvae pupate in leaf litter on the soil surface and thus are exposed to ants and other soil-active predators. Predation by ants on Diorhabda pupa was evaluated as a potential factor in limiting establishment of Diorhabda populations at field sites in West Texas. Nighttime observations of pupae found that native ants represented 46-65% and pill bugs (Isopoda: Armadillidiidae) represented 8-51% of observed predation events. The predation rate of Diorhabda pupae by ants was significantly greater where red imported fire ant, Solenopsis invicta Buren, was present. When present, S. invicta was responsible for 93-100% of observed predation during the day. In the absence of S. invicta, native ants Monomorium spp., Crematogaster spp., and Formica perpilosa Wheeler were observed preying on Diorhabda pupae. Results suggested that predation by ants, especially red imported fire ant, could limit establishment of Diorhabda spp. released for biological control of saltcedar.

Determination of the Polyphenolic Content of Dorycnium herbaceum Plant Extract and Testing in vivo Antioxidant Effect, Comparative with Bilberry

Dorycnium herbaceum (DH) is a perennial herb or small shrub 10-80 cm high, which can be found in Central and Southeastern Europe. It is a little studied plant, which is known to have antibacterial and antifungal effect. In the present study we determined by spectrophotometric methods the total polyphenolic, flavonoidic, carotenic and chlorophyllic content of DH species, comparative to the bilberry. We also monitored the status of antioxidant enzymes using mice with oxidative stress induced by streptozotocinic diabet. For the induction of diabetes we used Swiss albino mice to which we injected streptozotocin intraperitoneally at a single dose of 180 mg / kg b.w.. The results showed that both chemical composition tinctures contain appreciable amounts of polyphenols, the highest content starring DH tincture species, but bilberry fruits have higher content of flavonoids, carotene and chlorophyll. Both plant extracts regulate the status of antioxidant enzymes, DH having superior efficacy.

Acute and sub-acute (30-day) toxicity studies of Aegialitis rotundifolia Roxb., leaves extract in Wistar rats: safety assessment of a rare mangrove traditionally utilized as pain antidote

BackgroundAegialitis rotundifolia Roxb., (Plumbaginaceae) is a small mangrove tree or shrub traditionally used by the local healers of mangroves for curing pain and inflammation. However, there are no scientific reports of its toxicological properties which would guarantee the safety of its folkloric usage as a potent pain reliever. Therefore, the present study deals in acute and sub-acute (30-day) toxicity studies of Aegialitis rotundifolia ethanolic leaves extract (ARELE) on male and female Wistar rats administered through oral gavage.MethodsAcute toxicity study was conducted at a single oral dose of 1000, 1500, and 2000 mg/kg, body weight (b.wt.) for 14 days with a special emphasis on the first four hours after drug administration to find out any mortality and morbidity. In sub-acute toxicity, the extract at the doses of 125, 250 and 500 mg/kg, b.wt., was administered orally for 30 days. Important parameters such as general behaviour, body and organ weight, urinalysis, haematological and biochemical profile, organ macroscopy and microscopy were conducted. Organ sample of liver, kidney, pancreas, heart, lungs, and stomach were taken from both male and female rats, whereas the sample of testis and ovary was taken from male and female rats respectively for organ necropsy and histopathological studies. Neurobehavioral toxicity was conducted by performing a functional observational battery (FOB) and locomotor activity on the initial and final week of the 30-day study period.ResultsNo mortality or any major signs of morbidity was recorded for acute toxicity except for the limit dose (2000 mg/kg, b.wt.) which produced a slight short-term sedative effect. In sub-acute toxicity, no major alteration was observed in the evaluated parameters. However, few minor changes were recorded for high dose (500 mg/kg, b.wt.) group.ConclusionThe results of the present study showed that oral administration of Aegialitis rotundifolia ethanolic leaves extract did not produce any severe toxic effects in both acute and sub-acute studies in Wistar rats. Therefore, usage of an appropriate amount of Aegialitis rotundifolia leaves extract preferably at low doses for its traditional use should be considered safe.

Biological invasion threatens the sandy-savanna Mussununga ecosystem in the Brazilian Atlantic Forest

The sandy-savanna Mussununga is a little-known ecosystem that is already presenting signs of degradation due to effects of invasive species, anthropogenic disturbances, and land-use change. We investigated the effect of biological invasion by Acacia mangium and A. auriculiformis, disturbance promoted by fire and Eucalyptus management, as well as land-use change around Mussununga patches in this neglected ecosystem. Acacia occurrence is negatively related to abundance, basal area, and height of native woody species, and positively correlated with the proportion of dead woody plants. There is a trend of change in vegetation type from open savanna to woodland Mussununga promoted by Acacia. Mussununga patches disturbed by the planting of Eucalyptus species in the past have greater richness in the woody layer (large shrubs and trees), but lower abundance of species in the ground layer (small shrubs and herbs). The land-use change from forest to Eucalyptus plantation was associated with an increase of richness and abundance in the ground layer. Acacia tends to dominate the woody community in Mussununga by invading treeless patches, presenting a correlation with death of woody plants. Subsequently, Acacia promotes several changes that culminate in a height increment and change of the vegetation type. Different from Acacia, disturbance and land-use change associated with Eucalyptus, the main economic activity in the study area, affected both woody and ground layers. The conservation of Mussununga should include actions to preclude disturbance and land-use change, as well as monitoring and control of biological invasion.

Erysiphe diffusa causing powdery mildew on Mimosa caesalpiniifolia in Brazil: A soya bean pathogen found on an important native Brazilian tree

AbstractMimosa caesalpiniifolia: Fabaceae (sansão‐do‐campo or sabiá, in Brazil) is a small tree or shrub native to the Brazilian semi‐arid forest and widely used as a hedge plant in Brazil. Although of economic relevance, little is known of fungal pathogens infecting this plant. Recently, plants growing in an urban situation at Ouro Preto, and also on the roadside in Viçosa (state of Minas Gerais, Brazil), were found to be severely attacked by a powdery mildew which led to progressive leaf blight and serious defoliation. Based on morphology and molecular phylogenetic analysis of nuclear rDNA sequences, the fungus was identified as Erysiphe diffusa—a pathogen best known attacking soya bean, particularly in highland plantings.