Conyza Bonariensis Research Articles

Multivariate approach applied to phenotypic traits as a function of the selection of soybean cultivars

The objective of this work was to identify superior soybean cultivars through a multivariate approach applied to phenotypic traits. This study was developed in the 2023/2024 agricultural harvest, in the experimental area of ​​the Regional Institute for Rural Development, at UNIJUÍ. It is located in the municipality of Augusto Pestana, in the state of Rio Grande do Sul, Brazil. The experimental design used was randomized blocks with internal blocks, with the treatment being ten cultivars and five replications. The trial of ten cultivars in the northwest of the state of Rio Grande do Sul demonstrated that the soybean cultivar with the highest yield was NS5922IPRO, with 5235.3 kg ha-1. The multivariate approaches formed two groups to explain the factors that influenced yield, where the first was discrepant for the variables Euschistus heros, phytotoxicity, Fusarium solanie, Macrophomina phaseolina, Conyza bonariensis, production zone area, number of total nodes in the branch, branch number, root length, number of vegetables with 4 grains, number of vegetables with 0 grains and vegetable grain weight of 2 grains. The second similar group for the variables Diabrotica speciosa, Caliothrips brasiliensis, Euschisthus heros, Phakopsora pachyrhizi and Cercospora sojina, area of ​​production zone, number of vegetables with zero grains. The trial of ten cultivars in the northwest of the state of Rio Grande do Sul demonstrated that the soybean cultivar with the highest yield was NS5922IPRO, with 5235.3 kg ha-1. The multivariate approaches formed two groups to explain the factors that influenced grain yield.

The impact of kaolin mining activities on bacterial diversity and community structure in the rhizosphere soil of three local plants.

Thus far, the impact of kaolin mining activities on the surrounding native plants and rhizosphere microecology has not been fully understood. In this study, we used 16S rRNA high-throughput sequencing to examine the impact of kaolin mining on the rhizosphere bacterial communities and functions of three local plant species: Conyza bonariensis, Artemisia annua, and Dodonaea viscosa. The results showed that kaolin mining significantly reduced the diversity of rhizosphere bacteria in these plants, as indicated by the Shannon, Simpson, Chao1, and observed species indices (p < 0.05). Kaolin mining had an impact on the recruitment of three rhizosphere bacteria native to the area: Actinoplanes, RB41, and Mycobacterium. These bacteria were found to be more abundant in the rhizosphere soil of three local plants than in bulk soil, yet the mining of kaolin caused a decrease in their abundance (p < 0.05). Interestingly, Ralstonia was enriched in the rhizosphere of these plants found in kaolin mining areas, suggesting its resilience to environmental stress. Furthermore, the three plants had different dominant rhizosphere bacterial populations in kaolin mining areas, such as Nocardioides, Pseudarthrobacter, and Sphingomonas, likely due to the unique microecology of the plant rhizosphere. Kaolin mining activities also caused a shift in the functional diversity of rhizosphere bacteria in the three local plants, with each plant displaying different functions to cope with kaolin mining-induced stress, such as increased abundance of the GlpM family and glucan-binding domain. This study is the first to investigate the effects of kaolin mining on the rhizosphere microecology of local plants, thus contributing to the establishment of soil microecological health monitoring indicators to better control soil pollution in kaolin mining areas.

Association of quizalofop-P-tefuril to 2,4-D in hairy fleabane (Conyza bonariensis) control: is the antagonism reciprocal to that observed in sourgrass (Digitaria insularis)?

Association of quizalofop-P-tefuril to 2,4-D in hairy fleabane (Conyza bonariensis) control: is the antagonism reciprocal to that observed in sourgrass (Digitaria insularis)?

Notes floristiques. Observations faites au Luxembourg (2022-2023)

The most important records of vascular plant species made in Luxembourg in 2022 and 2023 are presented. In total, 122 taxa are mentioned. Adiantum aleuticum, Amaranthus blitoides, Bidens radiata, Centranthus calcitrapae, Chiastophyllum oppositifolium, Dipsacus laciniatus, Hibiscus trionum, Lagurus ovatus, Lepidium didymum, Rumex patientia and Sedum hispanicum, as well as the potentially invasive species Erigeron bonariensis, Erigeron karvinskianus, Erigeron sumatrensis and Lysichiton americanus are newly listed species found in Luxembourg. The discoveries of new or confirmed locations for Atriplex nitens, Callitriche obtusangula, Carex brizoides, Dysphania botrys, Filago arvensis, Fumaria parviflora, Hylotelephium telephium subsp. fabaria, Leersia oryzoides, Orchis simia, Panicum barbipulvinatum, Serratula tinctoria and Stachys annua are remarkable. The invasive species Ailanthus altissima, Cochlearia danica, Crassula helmsii, Prunus laurocerasus and Senecio inaequidens are spreading further. The implementation of national action plans for threatened species and habitats, as well as systematic fieldwork carried out over the last years, have resulted in the discoveries of new locations of endangered and/or protected species; other, previously known sites, were confirmed.

Health clinic gardens as models for social-ecological systems: Floristic composition and potential utilization of plants in the Bojanala Platinum District North-West Province, South Africa

Health clinic gardens (HCGs) are social-ecological systems (SESs) associated with health clinics on government land and are intended to provide fresh vegetables and fruits to patients struggling to keep healthy immune systems. Little is known about their comparability to other garden types with regards to plant distribution and potential utilization, and thus their potential to address some of the challenges limiting ecosystem services (ESs) provision in other garden types. In this study, we report on the floristic composition and presence of utilitarian plant species at 105 HCGs across a district municipality in the North-West Province, South Africa. Different micro-gardens, including vegetable, medicinal, ornamental, natural vegetation, bare soil, orchard, hedge, and lawn micro-gardens, were identified. To understand plant composition, species were classified according to status of origin, invasive characteristics, Raunkiaer’s life-forms, growth forms, and potential usefulness. To determine the frequency of species occurrence we enumerated the number of gardens containing the respective species. Six-hundred and thirty-three species from 404 genera and 116 plant families were encountered. Cynodon dactylon (L.) Pers. and Urochloa mosambicensis (Hack.) Dandy, found in 91 % and 79 % of gardens, respectively, occurred the most. Herbaceous species were the most dominant, with Schkuhria pinnata (Lam.) Kuntze ex Thell. and Conyza bonariensis (L.) Cronquist occurring the most. Plant species richness was greater in the ornamental (282 species) and natural area (naga) (281 species) micro-gardens, while the hedge had the least (8 species). Fifty-five percent of species in the natural vegetation micro-garden were indigenous, compared to 44 % in the ornamental micro-garden. There was greater diversity in fruit-bearing plants, and most medicinal plant species (70 %) are used as a tonic. Health clinic gardens resemble home gardens and are well positioned to enhance ESs provision at the community scale. Future HCGs research should evaluate community usage of the gardens and the extent to which knowledge of useful plants and efficient gardening practices is upscaled to home gardens around HCGs.

Phylogenomics-driven host test list selection for weed biological control

A concern in weed biological control research is the potential for candidate biocontrol agents to impact not only the target weed but also native or economically important flora. The degree of evolutionary relatedness between the target weed species and a non-target species is a key predictor of the susceptibility of the non-target to the biocontrol agent. To manage this risk, biocontrol practitioners need to understand the phylogenetic position of the host weed relative to non-target plant species. However, comprehensively sampled phylogenetic trees are often unavailable, with incomplete information scattered across multiple publications. Further, older published phylogenies based on Sanger sequence data often lack branch resolution and support, which increases uncertainty in biocontrol decision making. Decreasing sequencing cost and technological advances have led to phylogenomic approaches being more widely used to understand evolutionary relationships between species. For example, target capture sequencing methods using bait kits such as Angiosperms353 enable cost-effective and timely phylogenomic-level analysis of flowering plant groups at different scales. Here, we introduce a workflow to embed a comprehensive understanding of evolutionary relationships into the efficient development of host test lists in weed biological control. We demonstrate the effectiveness of the workflow through a case study on the major crop weed flaxleaf fleabane (Erigeron bonariensis). Phylogenomic analysis was conducted on 280 species of the tribe Astereae (family Asteraceae) occurring in Australia and New Zealand, clarifying relationships between the target species and related clades of native and non-native Astereae. We consider the phylogenetic tree in the context of a previously proposed host test list and discuss taxonomic implications, highlighting avenues of future molecular-based work to uncover the origin of Australian fleabanes. This study provides a workflow and demonstrates the practical application of target sequence capture for phylogenomic inference to support risk analysis and decision making in classical weed biological control.

Unveiling allelopathic dynamics and impacts of invasive Erigeron bonariensis and Bidens pilosa on plant communities and soil parameters

Invasive alien species are becoming more and more prevalent worldwide, Erigeron bonariensis and Bidens pilosa are two invasive species of Asteraceae in Egypt. To mitigate their detrimental effects and understand their differences in invasiveness, we compared the allelopathic potentials of E. bonariensis and B. pilosa using leachates, decaying residues, and volatilization processes. Notably, the allelopathic variances in leachates were significant, influenced by plant types, concentrations, and response patterns of target plant traits, as indicated by EC50. The relative phytotoxicity of the invasive species decayed residues peaked between 20 and 25 days in the soil, with a positive correlation with concentrations and soil properties. The highest quantities of phenolic acids were chlorogenic acid and caffeic acid reaching (5.41 and 4.39 µg g−1) E. bonariensis and (4.53 and 4.46 µg g−1) B. pilosa, in leachates extracts respectively, while in the soil extract of decayed residues were coumaric acid and ferulic acid measuring (1.66 and 1.67 µg g−1) E. bonariensis and (1.47 and 1.57 µg g−1) B. pilosa, respectively. Using GC/MS analysis, the main volatile components in E. bonariensis were 1, 8 cineole (5.62%), and α-terpinene (5.43%) and iso-Caryophyllene (5.2%) which showed the greatest inhibitory effects. While B. pilosa main constituents were trans-sabinene (5.39%) and Camphene (5.11%), respectively. Finally, the high invasion level displayed from E. bonariensis (0.221) compared with B. pilosa (0.094) which correlated with the stronger allelopathic activities against plant species, and soil properties. Therefore, the allelopathic potentialities of these species are critically relevant to their invasion success.

The Diversity and Community Composition of Three Plants' Rhizosphere Fungi in Kaolin Mining Areas.

Mining activities in the kaolin mining area have led to the disruption of the ecological health of the mining area and nearby soils, but the effects on the fungal communities in the rhizosphere soils of the plants are not clear. Three common plants (Conyza bonariensis, Artemisia annua, and Dodonaea viscosa) in kaolin mining areas were selected and analyzed their rhizosphere soil fungal communities using ITS sequencing. The alpha diversity indices (Chao1, Shannon, Simpson, observed-species, pielou-e) of the fungal communities decreased to different extents in different plants compared to the non-kauri mining area. The β-diversity (PCoA, NMDS) analysis showed that the rhizosphere soil fungal communities of the three plants in the kaolin mine area were significantly differentiated from those of the control plants grown in the non-kaolin mine area, and the extent of this differentiation varied among the plants. The analysis of fungal community composition showed that the dominant fungi in the rhizosphere fungi of C. bonariensis and A. annua changed, with an increase in the proportion of Mycosphaerella (genus) by about 20% in C. bonariensis and A. annua. An increase in the proportion of Didymella (genus) by 40% in D. viscosa was observed. At the same time, three plant rhizosphere soils were affected by kaolin mining activities with the appearance of new fungal genera Ochrocladosporium and Plenodomus. Predictive functional potential analysis of the samples revealed that a significant decrease in the potential of functions such as biosynthesis and glycolysis occurred in the rhizosphere fungal communities of kaolin-mined plants compared to non-kaolin-mined areas. The results show that heavy metals and plant species are the key factors influencing these changes, which suggests that selecting plants that can bring more abundant fungi can adapt to heavy metal contamination to restore soil ecology in the kaolin mining area.

Exploring nature's antidote: unveiling the inhibitory potential of selected medicinal plants from Kisumu, Kenya against venom from some snakes of medical significance in sub-Saharan Africa.

Background: The present study investigated the efficacy of Conyza bonariensis, Commiphora africana, Senna obtusifolia, Warburgia ugandensis, Vernonia glabra, and Zanthoxylum usambarense against Bitis arietans venom (BAV), Naja ashei venom (NAV), and Naja subfulva venom (NSV). Methods: 40 extracts and fractions were prepared using n-hexane, dichloromethane, ethyl acetate, and methanol. In vitro efficacy against snake venom phospholipase A2 (svPLA2) was determined in 96-well microtiter and agarose-egg yolk coagulation assays. in vivo efficacy against venom-induced cytotoxicity was determined using Artemia salina. Two commercial antivenoms were used for comparison. Results: The 96-well microtiter assay revealed poor svPLA2 inhibition of BAV by antivenom (range: 20.76% ± 13.29% to 51.29% ± 3.26%) but strong inhibition (>90%) by dichloromethane and hexane fractions of C. africana, hexane and ethyl acetate extracts and fraction of W. ugandensis, dichloromethane fraction of V. glabra, and the methanol extract of S. obtusifolia. The methanol extract and fraction of C. africana, and the hexane extract of Z. usambarense strongly inhibited (>90%) svPLA2 activity in NAV. The hexane and ethyl acetate fractions of V. glabra and the dichloromethane, ethyl acetate, and methanol extracts of C. africana strongly inhibited (>90%) svPLA2 in NSV. The agarose egg yolk coagulation assay showed significant inhibition of BAV by the dichloromethane fraction of C. africana (EC50 = 3.51 ± 2.58μg/mL), significant inhibition of NAV by the methanol fraction of C. africana (EC50 = 7.35 ± 1.800μg/mL), and significant inhibition of NSV by the hexane extract of V. glabra (EC50 = 7.94 ± 1.50μg/mL). All antivenoms were non-cytotoxic in A. salina but the methanol extract of C. africana and the hexane extracts of V. glabra and Z. usambarense were cytotoxic. The dichloromethane fraction of C. africana significantly neutralized BAV-induced cytotoxicity, the methanol fraction and extract of C. africana neutralized NAV-induced cytotoxicity, while the ethyl acetate extract of V. glabra significantly neutralized NSV-induced cytotoxicity. Glycosides, flavonoids, phenolics, and tannins were identified in the non-cytotoxic extracts/fractions. Conclusion: These findings validate the local use of C. africana and V. glabra in snakebite but not C. bonariensis, S. obtusifolia, W. ugandensis, and Z. usambarense. Further work is needed to isolate pure compounds from the effective plants and identify their mechanisms of action.

Effect of Alcoholic Extract of the Plant Conyza bonariensis on the Parasite Hymenolepis nana in Albino Mice Infected with it Experimentally

This study was conducted to investigate the effect of an alcoholic extract of the Mountain grass plant Conyza bonariensis on adults of the dwarf tapeworm Hymenolepis nana in albino mice infected with it experimentally, where Albino mice of the strain Balb/C were infected with these worms experimentally, it was divided into 5 groups, each group consisting of 6 rats, where the first group (control) was given distilled water only. As for the other groups, they were dosed with different concentrations of the alcoholic extract of the plant 50, 100, and 200 mg/kg, The last group was given 15 mg/kg of Niclosamide in one dose per day for 13 days. The results showed the effective effect of the concentrations of the alcoholic extract and the drug Niclosamide in the treatment of albino mice, and it produced a high therapeutic efficiency of 100%, with a variation in the period required for complete treatment and complete elimination of helminths, where the highest concentration of 200 mg/kg and the use of the drug led to a complete recovery of the infected Albino mice during the ninth day of treatment, and it was noted that the worm eggs disappeared from the swabs of the treated mice, while the infection continued in the control group until the thirteenth day, then died after that.

Neuroprotective potential of Erigeron bonariensis ethanolic extract against ovariectomized/D-galactose-induced memory impairments in female rats in relation to its metabolite fingerprint as revealed using UPLC/MS

Erigeron bonariensis is widely distributed throughout the world's tropics and subtropics. In folk medicine, E. bonariensis has historically been used to treat head and brain diseases. Alzheimer’s disease (AD) is the most widespread form of dementia initiated via disturbances in brain function. Herein, the neuroprotective effect of the chemically characterized E. bonariensis ethanolic extract is reported for the first time in an AD animal model. Chemical profiling was conducted using UPLC–ESI-MS analysis. Female rats underwent ovariectomy (OVX) followed by 42 days of D-galactose (D-Gal) administration (150 mg/kg/day, i.p) to induce AD. The OVX/D-Gal-subjected rats received either donepezil (5 mg/kg/day) or E. bonariensis at 50, 100, and 200 mg/kg/day, given 1 h prior to D-Gal. UPLC–ESI-MS analysis identified 42 chemicals, including flavonoids, phenolic acids, terpenes, and nitrogenous constituents. Several metabolites, such as isoschaftoside, casticin, velutin, pantothenic acid, xanthurenic acid, C18-sphingosine, linoleamide, and erucamide, were reported herein for the first time in Erigeron genus. Treatment with E. bonariensis extract mitigated the cognitive decline in the Morris Water Maze test and the histopathological alterations in cortical and hippocampal tissues of OVX/D-Gal-subjected rats. Moreover, E. bonariensis extract mitigated OVX/D-Gal-induced Aβ aggregation, Tau hyperphosphorylation, AChE activity, neuroinflammation (NF-κBp65, TNF-α, IL-1β), and apoptosis (Cytc, BAX). Additionally, E. bonariensis extract ameliorated AD by increasing α7-nAChRs expression, down-regulating GSK-3β and FOXO3a expression, and modulating Jak2/STAT3/NF-ĸB p65 and PI3K/AKT signaling cascades. These findings demonstrate the neuroprotective and memory-enhancing effects of E. bonariensis extract in the OVX/D-Gal rat model, highlighting its potential as a promising candidate for AD management.Graphical

An environmentally sustainable approach for the utilization of Erigeron bonariensis as a green inhibitor against weathering steel corrosion in acidic media.

In the realm of corrosion mitigation, the search for sustainable and ecologically accountable inhibitors attracts significant interest from the environmental point of view. This study investigates the intriguing possibilities presented by Erigeron bonariensis (EB) as a green and innovative corrosion inhibitor for weathering steel in 1 M H2SO4. EB, a naturally abundant plant species, holds promise as a green and sustainable inhibitor due to its inherent chemical composition in the environment. The intricate interplay between the phytochemical constituents of the extract and the corrosive environment is meticulously deciphered. Furthermore, the environmentally benign nature of the inhibitor adds an extra layer of significance to its application, aligning with contemporary green chemistry principles. The inhibition effect of Erigeron bonariensis (EB) extract on the corrosion of mild steel in acidic media (H2SO4) was studied using weight loss, absorption studies, phytochemical analysis, electrochemical methods, and scanning electron microscopy. The experimental findings revealed that an increase in inhibitor concentration is correlated with higher inhibition efficiency. The adsorption of inhibitor molecules on the mild steel surface was found to agree with the UV-Vis adsorption spectrum. Additionally, a surface study conducted using scanning electron microscopy indicated notable differences in the presence and absence of inhibitors for weathering steel. At 2000 mg L-1, EB extract has the best inhibitory efficiency for weathering steel in 1 M H2SO4 of 99.50% by the leaf part, followed by 94.35% by the flower part, and 85.22% by the stem part. Overall, this study suggests that EB extract serves as a promising alternative for corrosion prevention, demonstrating significant inhibition efficiency.

Conyza bonariensis (L.) Impact on Carbohydrate Metabolism and Oxidative Stress in a Type 2 Diabetic Rat Model

This study was conducted to assess the possible antidiabetic potential of Conyza bonariensis by employing in vitro as well as in vivo assessments. The dried plant material was extracted in methanol, ethanol, and water. The in vitro results showed that the ethanolic extract (EthCb) was found to have higher antioxidant and antidiabetic potential as compared with the aqueous (AqCb) and methanolic extracts (MthCb) so it was further evaluated in the in vivo trial using a diabetic rat model. Diabetes was induced in male Wistar rats by administering 5% sucrose in drinking water and a cafeteria diet for 8 weeks, followed by nicotinamide and streptozotocin administration. Subsequently, the diabetic rats were divided into 4 groups (n = 8 each): Positive control (no treatment), standard control (Metformin @ 10 mg/kg bw), treatment 1 ( C. bonariensis ethanolic extract @ 200 mg/kg bw), and treatment 2 ( C. bonariensis ethanolic extract @ 400 mg/kg bw). In addition, there was a negative control group of 8 rats without diabetes induction or treatment. After 21 days of treatment, blood samples were collected from all rats. The serum was evaluated through different means for glucose level, lipid profile, oxidative stress, carbohydrate metabolic enzymes and thyroid hormones. ANOVA was used to evaluate the data statistically. Total oxidant status (TOS) and the serum glucose levels of the streptozotocin-treated rats were reduced significantly ( P ⩽ .05) in Conyza bonariensis treated group. Whereas total antioxidant capacity (TAC) along with enzymes like paraoxonase and arylesterase were increased in Conyza bonariensis treated group. The antihyperlipidemic activity was also observed in Conyza bonariensis treated group Interestingly the subnormal levels of T3 and T4 which were observed in the PC group were also normalized in both treatment groups. This study demonstrated the antidiabetic as well as antioxidant activity of different extracts of Conyza bonariensis.

Extratos vegetais como promotores de germinação e estabelecimento de plântulas de alface e milho

ABSTRACT: Substances produced by plants have huge importance regulating multiple functions as germination, development promoter/enhancer, yield increaser and activator of plant defense system against diseases and pests. Due to diversity, each plant species produces different compounds and in different concentrations. This research evaluated the role of 20 plants extracts obtained from different plant species or plant tissues on seed germination and seedlings establishment of maize and lettuce, in concentration of 5%, 10% or 20%. For this, two experiments were carried out, the first analyzing 20 plant extracts and the effects on germination percentage and root and shoot length based on the germination test for the two species. The second was carried out in a greenhouse, in a completely randomized design with three and ten repetitions for maize and lettuce, respectively, using only the three extracts with the best results from the first experiment. Seedling height and seedling dry matter were evaluated. To germination test most of extracts showed negative or no effects in both species. Only Conyza bonariensis at 5% and Richardia brasiliensis at 5% and 20% had positive effects on early seedling growth, increasing the seedlings length for maize seedlings. To seedlings establishment, Conyza bonariensis, Leucaena leucocephala and Richardia brasiliensis extracts did not show statistical difference to shoots height but increased the dry mass of shoots and roots. The results demonstrated that these plants extract have potential as growth promoters and can be a good option to a better seedling growth and establishment, collaborating to a more effective agriculture.

Morphophysiological responses of bean cultivars in competition with Conyza bonariensis

Morphophysiological responses of bean cultivars in competition with Conyza bonariensis

KARYOSYSTEMATICS STUDY OF SOME ASTERACEAE SPECIES (COMPOSITAE) IN SAUDI ARABIA

Chromosome numbers were reported for 10 species of family Asteraceae from Saudi Arabia. The new count was reported in Pulicaria schimperi L. Karyotype analysis weremade for all species, Conyza bonariensis (L.) Cronquist 2n=18, Bidens pilosa L., 2n=70, Pluchea dioscoridis (L.) DC. 2n=32, Pulicaria schimperi L. 2n=12, Lactuca serriola L.2n=18, Launaea capitata (Spreng.) Dandy 2n=18, Launaea resedifolia (L.) Kuntze 2n=18, Launaea nudicaulis (L.) Hook. F. 2n=18, Reichardia tingitana (L.) Roth 2n=16, and Sonchus oleraceus L. 2n=32, belonging to 4 tribes: Astereae, Heliantheae, Inulea and Lactuceae. Pulicaria schimperi L. has the lowest chromosome number (2n=12), while the highest number of (2n=70) is recorded in Bidens pilosa L.

Fungitoxic effect and phytochemical characteristics of Brazilian Cerrado weeds against Rhizoctonia solani and Macrophomina phaseolina fungi.

The use of natural products obtained from plants, for example, invasive plants, offers a variety of allelochemicals with fungicidal potential. With this in perspective, the objective was to evaluate the fungicidal potential of ethanolic extracts of Cerrado plants on Rhizoctonia solani and Macrophomina phaseolina. The ethanolic hydroalcoholic extract of the 12 plants identified as invaders in the Brazilian Cerrado was prepared (Anacardium humile Saint Hill; Baccharis dracunculifolia DC.; Cenchrus echinatus L; Commelina erecta L.; Erigeron bonariensis L.; Digitaria horizontalis Willd.; Digitaria insularis L.; Porophyllum ruderale Jacq. Cass; Richardia brasiliensis Gomes; Sida rhombifolia L.; Turnera ulmifolia L.; Smilax fluminensis Steud)) and phytochemical screening and determination of total phenols and flavonoids were performed. To evaluate the in vitro antifungal activity, the hydroalcoholic solutions at concentrations of 800, 1200, 1600, 2000, and 2400 µL 100 mL-1 were separately incorporated into BDA agar and poured into Petri dishes, followed by the mycelium disk of the fungus. As a control, two solutions were prepared, one ethanolic solution added to the BDA medium (2400 µg 100 mL-1) and the other with BDA medium only. They were poured into Petri dishes, followed by a 0.5 cm diameter disk of mycelium of the fungus, incubated (23±2 ºC), with a 24-hour photoperiod. Among the constituents found in the plants, 75% are phenolic compounds, 58.3% are cardiotonic heterosides, 50% are steroids, 33.3% are flavonoids, 16.7% are anthraquinones, and 8.3% are alkaloids, saponins, and reducing sugars. Out of the 12 species, only the extracts of C. erecta and R. brasiliensis were active for M. phaseolina and R. solani. Thus, it is concluded that the ethanolic extract of C. erecta has the fungicidal potential to control diseases caused by fungi that are soil inhabitants. Of the other species, A. humille, B. dracuncufolia, D. insulares, C. erecta, D. insulares, P. ruderale, and R. brasiliensis have natural fungitoxic potential because they stand out in the content of polyphenols efficient in reducing the mycelial growth of M. phaseolina and R. solani.

Synthesis and biological evaluation of natural Lachnophyllum methyl ester, Lachnophyllum lactone and their synthetic analogs.

(2Z)-Lachnophyllum methyl ester and (4Z)-Lachnophyllum lactone were recently identified as major components in essential oils and extracts of Conyza bonariensis from Togo. Extended biological evaluation of these acetylenic compounds was however hampered by the reduced amounts isolated. A synthetic route was designed providing access to larger quantities of these two natural products as well as to original non-natural analogs with the prospect of exploring for the first time the structure-activity relationships in this series. Using LC/MS analysis, synthetic samples allowed confirming the presence of the two previously isolated natural products in plant extracts obtained by the accelerated solvent extraction technique. The nematocidal activity of the synthesized compounds confirmed the potency of the natural products, which remain the most active among all analogs tested. The synthesized compounds were also assessed against Leishmania infantum axenic amastigotes and the Mycobacterium tuberculosis H37Rv pathogenic strain. (2Z)-Lachnophyllum methyl ester, (4Z)-Lachnophyllum lactone and lactone analogs exhibited the strongest antileishmanial potency. As expected, a longer alkyl chain was necessary to observe significant antimycobacterial activity. The lactone analog bearing a C10 lipophilic appendage displayed the highest antimycobacterial potency. The notable activities of lactones, naturally occurring or analogs, either nematicidal, antileishmanial or antimycobacterial, were compared to their cytotoxicity for mammalian cells and revealed moderate selectivity index values. In this regard, the innocuous (2Z)-Lachnophyllum methyl ester and its analogs open up more promising perspectives for the discovery of bioactive agents to protect both agricultural crops and human health.

Chemical control and herbicide resistance of hairy fleabane (Erigeron bonariensis L.) in Jordan.

The effect of paraquat, oxadiazon and oxyfluorfen herbicides was tested on two populations of hairy fleabane (Erigeron bonariensis L.), collected from a date palm orchard at Tal al-Ramil (Central Jordan Valley) and al-Twal (Northern Jordan Valley) sites using the recommended rates (0.5, 1.25 and 0.792kg a.i ha-1 for each herbicide, respectively) and 10-fold (5, 12.50 and 7.92 kg a.i. ha-1, respectively) under glasshouse conditions. Results showed that the date palm weed population was resistant to the three herbicides at both application rates and al-Twal site population was highly susceptible. Two field experiments were conducted to evaluate the effectiveness of 12 herbicides in controlling the weed in the date palm orchard during the spring of 2017, revealed that E. bonariensis resists paraquat (0.5, 1.0 and 1.5 kg a.i. ha-1), oxadiazon (1.25 kg a.i. ha-1) and oxyfluorfen (0.792 kg a.i. ha-1) herbicides. None of the three herbicides was effective against the weed and treated plants continued to grow normally similar to those of untreated control. Ten-fold higher rates of these herbicides failed to control the weed. The effect of other tested herbicides was variable with bromoxynil plus MCPA (buctril®M), 2,4-D- iso-octyl ester, glyphosate, glyphosate trimesium and triclopyr being the most effective and completely controlling the weed at recommended rates of application. It is concluded that the tested populations of E. bonariensis developed resistance to paraquat, oxadiazon and oxyfluorfen but control of the weed was possible using other herbicides with different mechanisms of action. Herbicide rotation or other nonchemical weed control methods have been suggested to prevent or reduce the buildup and spread of resistant populations of this weed. These results represent the first report of herbicide resistance of E. bonariensis in Jordan.

Chemical Composition, In Vitro Antitumor Effect, and Toxicity in Zebrafish of the Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae).

The essential oil from Conyza bonariensis (Asteraceae) aerial parts (CBEO) was extracted by hydrodistillation in a Clevenger-type apparatus and was characterized by gas chromatography-mass spectrometry. The antitumor potential was evaluated against human tumor cell lines (melanoma, cervical, colorectal, and leukemias), as well as non-tumor keratinocyte lines using the MTT assay. The effect of CBEO on the production of Reactive Oxygen Species (ROS) was evaluated by DCFH-DA assay, and a protection assay using the antioxidant N-acetyl-L-cysteine (NAC) was also performed. Moreover, the CBEO toxicity in the zebrafish model was assessed. The majority of the CBEO compound was (Z)-2-lachnophyllum ester (57.24%). The CBEO exhibited selectivity towards SK-MEL-28 melanoma cells (half maximal inhibitory concentration, IC50 = 18.65 ± 1.16 µg/mL), and induced a significant increase in ROS production. In addition, the CBEO's cytotoxicity against SK-MEL-28 cells was reduced after pretreatment with NAC. Furthermore, after 96 h of exposure, 1.5 µg/mL CBEO induced death of all zebrafish embryos. Non-lethal effects were observed after exposure to 0.50-1.25 µg/mL CBEO. Additionally, significant alterations in the activity of enzymes associated with oxidative stress in zebrafish larvae were observed. These results provide evidence that CBEO has a significant in vitro antimelanoma effect by increasing ROS production and moderate embryotoxicity in zebrafish.