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E T F Witkowski - One of the best experts on this subject based on the ideXlab platform.
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interactions between a stem gall fly and a leaf spot pathogen in the biological control of Ageratina adenophora
Biological Control, 2012Co-Authors: Lisa Buccellato, Marcus J Byrne, E T F WitkowskiAbstract:Abstract Many biological control projects involve the release of multiple agents. Ageratina adenophora (crofton weed) has two agents, Procecidochares utilis , a stem gall fly, and Passalora Ageratinae , a leaf-spot fungal pathogen, released against it in South Africa. This study investigated whether both agents, individually or jointly, increased or decreased the impact on crofton weed under greenhouse conditions. Six-month-old plants were exposed to one of six treatments ( n = 15 plants/treatment): control (no agents), pathogen-only, single-galled only, double-galled only, pathogen-single-galled, and pathogen-double-galled, all for a period of 6 months. Individually, both of the agents reduced stem height and percentage of live leaves, but there was no synergistic effect of the two agents together. Pathogen-double-galled stems had significantly fewer pathogen-infected leaves relative to the other pathogen-infected treatment stems, suggesting a negative interaction between the two agents on pathogen establishment. Pathogen infection did not affect the size of the galls. Double galling by the fly inhibited stem growth above the gall position on the stem. Crofton weed compensated for galling by increasing the number of sideshoots. The pathogen inhibited sideshoot growth, thereby curbing the plant’s ability to offset galling. Overall, there was an additive interaction between the two agents which enhances their usefulness as biocontrol agents of crofton weed.
Stephen G Compton - One of the best experts on this subject based on the ideXlab platform.
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impacts of a biocontrol agent on invasive Ageratina adenophora in southwest china friend or foe
Biological Control, 2020Co-Authors: Chuan Yuan, Qin Wang, Yan Chen, Lidan Zhang, Lu Tan, Jintian Yang, Mei Liu, Stephen G ComptonAbstract:Abstract Classical biological control of invasive plants depends on the introduction of host-specific natural enemies. Many natural enemies have provided successful control, but the impacts of herbivorous insects on their hosts are highly variable and context dependent. Under some circumstances, overcompensation can even occur, with plant reproduction temporarily increasing rather than decreasing in response to herbivory. The stem-galling fly Procecidochares utilis has been widely introduced to help control Ageratina adenophora, a globally significant weed, but its impact has been inconsistent and in places ineffective. Its galling is known to stimulate production of side branches in plants under laboratory conditions. We examined the abundance and impact of P. utilis at four A. adenophora sites of Southwest China that were invaded at different times and support different densities of the insect. Stems with galls were more likely to be branched and produced more capitula. Furthermore, seed numbers in capitula from galled and un-galled stems were similar, and galling resulted in only slightly reduced seed weights. However, the increase in above-ground vegetative biomass associated with branching resulted in less efficient capitulum production relative to vegetative growth. Clearly Procecidochares utilis is not providing effective biocontrol of Ageratina adenophora in Southwest China so far. In the long term, galled plants may display reduced competitive ability and lower lifetime reproductive success, but the short term increases in seed production it generates suggest it may be favouring its host’s range expansion. The fly has been a successful biocontrol agent in dry area of Hawii, so understanding the factors that determine its effectiveness represent a major challenge for the future.
Lisa Buccellato - One of the best experts on this subject based on the ideXlab platform.
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An insect-plant pathogen interaction between two biocontrol agents, the stem-gall fly and leaf-spot pathogen released against crofton weed, Ageratina adenophora
2013Co-Authors: Lisa BuccellatoAbstract:iv TABLE OF CONTENTS vi LIST OF FIGURES x LIST OF TABLES xv CHAPTER 1: INTRODUCTION 1-1 1.1 Background 1-2 1.2 Aims and objectives 1-6 1.2.1 Objectives of the laboratory and field trials 1-7 1.2.2 Objectives of the field surveys 1-7 1.3 Study species 1-9 1.3.1 Ageratina adenophora 1-9 1.3.2 Procecidochares utilis 1-11 1.3.3 Passalora Ageratinae 1-12 1.4 Multiple biocontrol agent releases 1-14 1.5 Post-release evaluations 1-17 1.6 Field sites 1-19 1.7 Structure of the thesis 1-21 CHAPTER 2: INTERACTIONS BETWEEN A STEM GALL FLY AND A LEAF-SPOT PATHOGEN IN THE BIOLOGICAL CONTROL OF Ageratina ADENOPHORA. 2-1 2.1 Abstract 2-2 2.2 Introduction 2-3 2.3 Material and methods 2-6 2.3.1 Laboratory trials 2-7 2.3.2 Data analysis 2-10 2.4 Results 2-10 2.4.1 Impact of AMISTAR ® on Ageratina adenophora growth ... 2-10 2.4.2 Agent establishment and infection severity 2-10 2.4.3 Stem height 2-13 2.4.4 Stem growth above the oviposition site 2-13 2.4.5 Internode length above oviposition site 2-14
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interactions between a stem gall fly and a leaf spot pathogen in the biological control of Ageratina adenophora
Biological Control, 2012Co-Authors: Lisa Buccellato, Marcus J Byrne, E T F WitkowskiAbstract:Abstract Many biological control projects involve the release of multiple agents. Ageratina adenophora (crofton weed) has two agents, Procecidochares utilis , a stem gall fly, and Passalora Ageratinae , a leaf-spot fungal pathogen, released against it in South Africa. This study investigated whether both agents, individually or jointly, increased or decreased the impact on crofton weed under greenhouse conditions. Six-month-old plants were exposed to one of six treatments ( n = 15 plants/treatment): control (no agents), pathogen-only, single-galled only, double-galled only, pathogen-single-galled, and pathogen-double-galled, all for a period of 6 months. Individually, both of the agents reduced stem height and percentage of live leaves, but there was no synergistic effect of the two agents together. Pathogen-double-galled stems had significantly fewer pathogen-infected leaves relative to the other pathogen-infected treatment stems, suggesting a negative interaction between the two agents on pathogen establishment. Pathogen infection did not affect the size of the galls. Double galling by the fly inhibited stem growth above the gall position on the stem. Crofton weed compensated for galling by increasing the number of sideshoots. The pathogen inhibited sideshoot growth, thereby curbing the plant’s ability to offset galling. Overall, there was an additive interaction between the two agents which enhances their usefulness as biocontrol agents of crofton weed.
Marcus J Byrne - One of the best experts on this subject based on the ideXlab platform.
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interactions between a stem gall fly and a leaf spot pathogen in the biological control of Ageratina adenophora
Biological Control, 2012Co-Authors: Lisa Buccellato, Marcus J Byrne, E T F WitkowskiAbstract:Abstract Many biological control projects involve the release of multiple agents. Ageratina adenophora (crofton weed) has two agents, Procecidochares utilis , a stem gall fly, and Passalora Ageratinae , a leaf-spot fungal pathogen, released against it in South Africa. This study investigated whether both agents, individually or jointly, increased or decreased the impact on crofton weed under greenhouse conditions. Six-month-old plants were exposed to one of six treatments ( n = 15 plants/treatment): control (no agents), pathogen-only, single-galled only, double-galled only, pathogen-single-galled, and pathogen-double-galled, all for a period of 6 months. Individually, both of the agents reduced stem height and percentage of live leaves, but there was no synergistic effect of the two agents together. Pathogen-double-galled stems had significantly fewer pathogen-infected leaves relative to the other pathogen-infected treatment stems, suggesting a negative interaction between the two agents on pathogen establishment. Pathogen infection did not affect the size of the galls. Double galling by the fly inhibited stem growth above the gall position on the stem. Crofton weed compensated for galling by increasing the number of sideshoots. The pathogen inhibited sideshoot growth, thereby curbing the plant’s ability to offset galling. Overall, there was an additive interaction between the two agents which enhances their usefulness as biocontrol agents of crofton weed.
Leovigildo Quijano - One of the best experts on this subject based on the ideXlab platform.
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Further Thymol Derivatives from Ageratina cylindrica
Chemistry & Biodiversity, 2016Co-Authors: Celia Bustos-brito, José S. Calderón, Baldomero Esquivel, Fernando Calzada, Lilián Yépez-mulia, Javier Porras-ramirez, Leovigildo QuijanoAbstract:From the leaves of Ageratina cylindrica, in addition to the described [(2S)-2-{4-formyl-5-hydroxy-2-[(2-methylpropanoyl)oxy]phenyl}oxiran-2-yl]methyl benzoate (cylindrinol A, 8), seven new thymol derivatives were isolated and named cylindrinols B – H (1 – 7). The structures of these compounds were established as (2-{4-(hydroxymethyl)-2-[(2-methylpropanoyl)oxy]phenyl}oxiran-2-yl)methyl benzoate (1), (2-{4-formyl-2-[(2-methylpropanoyl)oxy]phenyl}oxiran-2-yl)methyl benzoate (2), (2-{4-[(acetyloxy)methyl]-2-[(2-methylpropanoyl)oxy]phenyl}oxiran-2-yl)methyl benzoate (3), [2-(2-[(2-methylpropanoyl)oxy]-4-{[(2-methylpropanoyl)oxy]methyl}phenyl)oxiran-2-yl]methyl benzoate (4), [2-(5-hydroxy-2-[(2-methylpropanoyl)oxy]-4-{[(2-methylpropanoyl)oxy]methyl}phenyl)oxiran-2-yl]methyl benzoate (5), 2-{4-(hydroxymethyl)-2-[(2-methylpropanoyl)oxy]phenyl}prop-2-en-1-yl benzoate (6), and 2-hydroxy-2-[2-hydroxy-4-(hydroxymethyl)-phenyl]-3-[(2-methylpropanoyl)oxy]propyl benzoate (7), by spectroscopic means. Compounds 1 showed moderate antiprotozoal activity on both protozoa. Compounds 4 and 5 showed selectivity on Giardia lamblia trophozoites. All isolated compounds were less active than two antiprotozoal drugs, metronidazole and emetine, used as positive controls. Compound 5 exhibited a high inhibitory effect on hyperpropulsive movement of the small intestine in rats; its effect was best than loperamide, antidiarrheal drug used as a positive control.
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Antidiarrheal Thymol Derivatives from Ageratina glabrata. Structure and Absolute Configuration of 10-Benzoyloxy-8,9-epoxy-6-hydroxythymol Isobutyrate.
Molecules, 2016Co-Authors: Celia Bustos-brito, José S. Calderón, Baldomero Esquivel, Fernando Calzada, Lilián Yépez-mulia, Valeria J. Vázquez-heredia, Simón Hernández-ortega, Normand García-hernández, Leovigildo QuijanoAbstract:Chemical investigation of the leaves from Ageratina glabrata yielded four new thymol derivatives, namely: 10-benzoyloxy-8,9-dehydro-6-hydroxythymol isobutyrate (4), 10-benzoyloxy-8,9-dehydrothymol (5), 10-benzoyloxythymol (6) and 10-benzoyloxy-6,8-dihydroxy-9-isobutyryl-oxythymol (7). In addition, (8S)-10-benzoyloxy-8,9-epoxy-6-hydroxythymol isobutyrate (1), together with other two already known thymol derivatives identified as 10-benzoyloxy-8,9-epoxy-6-methoxythymol isobutyrate (2) and 10-benzoyloxy-8,9-epoxythymol isobutyrate (3) were also obtained. In this paper, we report the structures and complete assignments of the 1H and 13C-NMR data of compounds 1–7, and the absolute configuration for compound 1, unambiguously established by single crystal X-ray diffraction, and evaluation of the Flack parameter. The in vitro antiprotozoal assay showed that compound 1 and its derivative 1a were the most potent antiamoebic and antigiardial compounds. Both compounds showed selectivity and good antiamoebic activity comparable to emetine and metronidazole, respectively, two antiprotozoal drugs used as positive controls. In relation to anti-propulsive effect, compound 1 and 1a showed inhibitory activity, with activities comparable to quercetin and compound 9, two natural antipropulsive compounds used as positive controls. These data suggest that compound 1 may play an important role in antidiarrheal properties of Ageratina glabrata.
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Antidiarrheal Thymol Derivatives from Ageratina glabrata. Structure and Absolute Configuration of 10-Benzoyloxy-8,9-epoxy-6-hydroxythymol Isobutyrate
2016Co-Authors: Celia Bustos-brito, José S. Calderón, Baldomero Esquivel, Fernando Calzada, Lilián Yépez-mulia, Valeria J. Vázquez-heredia, Simón Hernández-ortega, Normand García-hernández, Leovigildo QuijanoAbstract:Abstract: Chemical investigation of the leaves from Ageratina glabrata yielded four new thymol derivatives, namely: 10-Benzoyloxy-8,9-dehydro-6-hydroxythymol isobutyrate (4), 10-benzoyloxy-8,9-dehydro thymol (5), 10-benzoyloxythymol (6) and 10-benzoyloxy-6,8-dihydroxy-9-isobutyryloxythymol (7). In addition, (8S)-10-benzoyloxy-8,9-epoxy-6-hydroxythymol isobutyrate (1), together with other two already known thymol derivatives identified as: 10-benzoyloxy-8,9-epoxy-6-methoxythymol isobutyrate (2) and 10-benzoyloxy-8,9-epoxythymol isobutyrate (3). In this paper, we wish to publish the structures and complete assignments of 1H and 13C NMR data of compounds 1 – 7, and the absolute configuration for compound 1, unambiguously established by single crystal X-ray diffraction, and evaluation of the Flack parameter. The in vitro antiprotozoal assay showed that compound 1 and its derivative 1a were the most potent antiamoebic and antigiardial compounds. Both compounds showed selectivity and good antiamoebic activity like emetine and metronidazole, respectively, two antiprotozoal drugs used as positive controls. In relation of anti-propulsive effect, compound 1 and 1a showed moderate inhibitory activity, their activities were comparable to quercetin and compound 9, respectively, two natural antipropulsive compounds used as positive controls. These data suggest that compound 1 may play an important role in antidiarrheal properties of Ageratina glabrata.
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Acute hypoglycemic effect and phytochemical composition of Ageratina petiolaris.
Journal of Ethnopharmacology, 2016Co-Authors: Celia Bustos-brito, Adolfo Andrade-cetto, Juan David Giraldo-aguirre, Angelina Daniela Moreno-vargas, Leovigildo QuijanoAbstract:Abstract Ethnopharmacological relevance Type 2 diabetes is characterized by tissue resistance to the action of insulin combined with a relative deficiency in insulin secretion. In Mexico, medicinal plants have traditionally been used to control the disease; in this work, we investigate the hypoglycemic effect of Ageratina petiolaris , a plant used in Mexico for the treatment of diabetes. Methods The hypoglycemic effects of aqueous and methanolic extracts prepared from aerial parts of Ageratina petiolaris in streptozotocin-nicotinamide (STZ-NA) induced diabetic rats were assessed. An oral administration of the water extract at doses of 40 and 160 mg/kg and of the methanol extract at doses of 67 and 268 mg/kg were evaluated. Furthermore, the water extract at 160 mg/kg was evaluated under an Oral Glucose Tolerance Test. Results The tested extracts were able to reduce the increase in blood glucose level at three hours after administration. l - chiro -inositol and chlorogenic acid were isolated as important constituents of the plant, they were identified in both extracts along with other constituents. Conclusions The results presented here demonstrate that the main components in the aqueous extract of Ageratina petiolaris are chlorogenic acid and l - chiro -inositol, the last one with significant hypoglycemic activity, these results support the traditional use of this plant for the treatment of type 2 diabetes.
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ent-Kaurene Glycosides from Ageratina cylindrica.
Journal of Natural Products, 2015Co-Authors: Celia Bustos-brito, José S. Calderón, Mariano Sánchez-castellanos, Baldomero Esquivel, Fernando Calzada, Lilián Yépez-mulia, Pedro Joseph-nathan, Gabriel Cuevas, Leovigildo QuijanoAbstract:The aqueous extract of the leaves of Ageratina cylindrica afforded six new ent-kaurenoic acid glycosides together with the known diterpenoid paniculoside V, the flavonoid astragalin, chlorogenic acid, and L-chiro-inositol. The structures were elucidated mainly by NMR and MS methods, and the absolute configuration was established by vibrational circular dichroism spectroscopy. The new compounds showed moderate antiprotozoal activity against Entamoeba histolytica and Giardia lamblia trophozoites.
