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Jan Stenlid - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on the interaction between Phlebiopsis Gigantea and the root-rot forest pathogen Heterobasidion spp.
Forest Ecology and Management, 2015Co-Authors: Jonàs Oliva, Anan Zhao, Somayeh Zarei, Petr Sedlák, Jan StenlidAbstract:The biocontrol agent Phlebiopsis Gigantea is widely applied to stump surfaces during commercial thinning operations in Northern Europe to prevent airborne infection of Norway spruce (Picea abies) stumps by the root and butt-rot pathogen Heterobasidion spp. It has been suggested that warmer climatic conditions in the future may affect the interaction between the pathogen and the biocontrol agent, and may enable Heterobasidion annosum sensu stricto, which is currently restricted to southern areas of Sweden, to move further northward. To determine whether warm temperatures do effect the interaction between P. Gigantea and Heterobasidion spp., we conducted a series of experiments to investigate the effect of temperature on the growth of P. Gigantea and several Heterobasidion spp. and on the ability of P. Gigantea to overgrow Heterobasidion spp. in paired interaction experiments in vitro. To validate our in vitro findings, we set up field experiments to examine the interaction between P. Gigantea and the Heterobasidion spp. that infect spruce in Sweden, Heterobasidion parviporum and H. annosum s.s., under different temperature regimes. Our study showed that temperature did not diminish the effectiveness of P. Gigantea to protect spruce stumps against infection by H. parviporum. The growth rate of P. Gigantea in stumps was higher than that of H. parviporum, particularly in sapwood. We found little support for a hypothetical increase in H. annosum s.s. damage under warmer climatic conditions. In vitro studies showed that regardless of the temperature regime, H. annosum s.s. was less resistant to overgrowth by P. Gigantea than H. parviporum. Under field conditions, the relatively low infection capacity of H. annosum s.s. to P. abies stumps seems to be the crucial factor determining the outcome of the interaction. The results of paired in vitro experiments between P. Gigantea and non-European Heterobasidion species, for example, Heterobasidion araucariae, Heterobasidion irregulare and others, suggest that P. Gigantea may be less effective as a biocontrol agent against species or isolates adapted to high temperatures (20–25 °C), particularly those species that are able to grow rapidly at temperatures as high as 25 °C.
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Microsatellite markers for the wood decay fungus Phlebiopsis Gigantea
Conservation Genetics, 2009Co-Authors: Nicklas Samils, Brian P. Higgins, Campbell J Nairn, Bernard Slippers, Jan Stenlid, Sarah F. CovertAbstract:Nine polymorphic microsatellite markers were developed for the wood-decay basidiomycete Phlebiopsis Gigantea, which is used commercially as a biocontrol agent for annosum root disease on conifers. Microsatellite sequences were isolated from repeat-enriched genomic libraries. Primers flanking these sequences were screened on P. Gigantea isolates from Europe and North America. The number of alleles per locus ranged from 5 to 15, and gene diversity ranged from 0.72 to 0.90. These markers should be useful for studies of P. Gigantea natural population structure and for making predictions about the impact of P. Gigantea application in conifer forests.
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Sensitivity of Root Rot Antagonist Phlebiopsis Gigantea spores to high temperature or pressure
Scandinavian Journal of Forest Research, 1997Co-Authors: Magnus Thor, Malin Bendz-hellgren, Jan StenlidAbstract:Aqueous suspensions of Phlebiopsis Gigantea oidiospores, used as a biological control agent against Heterobasidion annosum, were either (1) set under pressure, (2) warmed or (3) used in mechanized stump treatment. Survival of P. Gigantea following these treatments was monitored by estimation of oidia germination on agar medium and compared with the germination of oidia from control suspensions. Pressure up to 2200 kPa had no effect on the survival of P. Gigantea. No effect on the survival was detected following incubation at ambient pressure for between 5 min and 8 h at 20°C. Phlebiopsis Gigantea spore germination had an optimum at 30°C. When exposed to temperatures exceeding 30°C, viability of P. Gigantea spores decreased with time. During mechanized stump treatment, survival of P. Gigantea was not significantly lower, neither after the suspension had passed through the stump treatment device nor after 7 h time, compared with a fresh control suspension. Thus, mechanized application under normal summer co...
Emmanuel Toppo - One of the best experts on this subject based on the ideXlab platform.
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Comparative study of antitoxin activity of Calotropis gigentea Linn and Cassia fistula Linn against Naja-naja (cobra) venom
International Journal of Green Pharmacy, 2011Co-Authors: Surabhi Pandey, Emmanuel Toppo, Preeti ChauhanAbstract:Calotropis Gigantea Linn and Cassia fistula Linn is used traditionally in India to treat snake bite patients. Hydroalcoholic extract of dried leaves of Calotropis Gigantea Linn and Cassia fistula Linn was tested for haemolysis, procoagulant, oedema-forming activity against cobra (Naja-Naja) venom. The hydroalcoholic extract showed a significant inhibitory effect on haemolysis, procoagulant, oedema-forming activity. Calotropis Gigantea Linn extract was significantly neutralize Naja-naja venom as compared to Cassia fistula Linn in a dose dependent manner. The present study suggests that hydroalcoholic extract of dried leaves of Calotropis Gigantea Linn and Cassia fistula Linn possess compounds, which neutralize the activity of cobra (Naja-Naja) venoms. Key words: Oedema forming, hemolysis, Naja-naja, procoagulant
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wound healing activity of calotropis Gigantea root bark in rats
Journal of Ethnopharmacology, 2009Co-Authors: Pradeep T. Deshmukh, Akarte Atul, Jennifer Fernandes, Emmanuel ToppoAbstract:Ethnopharmacological relevance: Calotropis Gigantea R.Br. (Asclepiadaceae) is a perennial undershrub found chiefly in wastelands throughout India. It has been reported as a traditional folkloric medicine for a variety of alignments. The plant Calotropis Gigantea is also used in some parts of India for wound healing in combination with other plants. However there are no scientific reports on wound healing activity of the plant Calotropis Gigantea R.Br. Aim of the study: To investigate the effects of Calotropis Gigantea root bark on wound healing activity in rats by excision, incision and dead space wound healing models in rats. Methodology: Wistar albino rats of either sex weighing between 180 and 200 g were topically treated with extract formulated in ointment by using simple ointment BP as base. 5% (w/w) ointment was applied once daily in excision wound model. Calotropis Gigantea ethanolic extract was given orally at a dose of 100, 200, and 400 mg/kg in incision and dead space wound healing models. Rats of standard groups were treated with 5% Povidone iodine ointment topically. The percentage wound closure, epithelization time, hydroxyproline content and scar area on complete epithelization were measured. Results: Topical application of Calotropis Gigantea in excision wound model increased the percentage of wound contraction. Scar area and epithelization time were decreased. In incision wound and dead space wound breaking strength of wounds and hydroxyproline was increased. Conclusion: Calotropis Gigantea accelerated wound healing in rats and thus supports its traditional use. © 2009 Elsevier Ireland Ltd. All rights reserved.
Pradeep T. Deshmukh - One of the best experts on this subject based on the ideXlab platform.
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wound healing activity of calotropis Gigantea root bark in rats
Journal of Ethnopharmacology, 2009Co-Authors: Pradeep T. Deshmukh, Akarte Atul, Jennifer Fernandes, Emmanuel ToppoAbstract:Ethnopharmacological relevance: Calotropis Gigantea R.Br. (Asclepiadaceae) is a perennial undershrub found chiefly in wastelands throughout India. It has been reported as a traditional folkloric medicine for a variety of alignments. The plant Calotropis Gigantea is also used in some parts of India for wound healing in combination with other plants. However there are no scientific reports on wound healing activity of the plant Calotropis Gigantea R.Br. Aim of the study: To investigate the effects of Calotropis Gigantea root bark on wound healing activity in rats by excision, incision and dead space wound healing models in rats. Methodology: Wistar albino rats of either sex weighing between 180 and 200 g were topically treated with extract formulated in ointment by using simple ointment BP as base. 5% (w/w) ointment was applied once daily in excision wound model. Calotropis Gigantea ethanolic extract was given orally at a dose of 100, 200, and 400 mg/kg in incision and dead space wound healing models. Rats of standard groups were treated with 5% Povidone iodine ointment topically. The percentage wound closure, epithelization time, hydroxyproline content and scar area on complete epithelization were measured. Results: Topical application of Calotropis Gigantea in excision wound model increased the percentage of wound contraction. Scar area and epithelization time were decreased. In incision wound and dead space wound breaking strength of wounds and hydroxyproline was increased. Conclusion: Calotropis Gigantea accelerated wound healing in rats and thus supports its traditional use. © 2009 Elsevier Ireland Ltd. All rights reserved.
Fred O. Asiegbu - One of the best experts on this subject based on the ideXlab platform.
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The impacts of treatment with biocontrol fungus (Phlebiopsis Gigantea) on bacterial diversity in Norway spruce stumps
Biological Control, 2013Co-Authors: Hui Sun, Lars Paulin, Eeva Terhonen, Kaisa Koskinen, Risto Kasanen, Fred O. AsiegbuAbstract:The biocontrol agent Phlebiopsis Gigantea has been intensively applied to the surface of Picea abies stumps to control Heterobasidion root rot. But little is known about the possible impact of this treatment on the resident bacteria community in the stumps. High throughput DNA bar-coded pyrosequencing was used to characterize the diversity of bacteria in the stumps of P. abies at 1, 6 and 13 years after treatment with P. Gigantea. The sequences were classified into 12 phyla and 160 genera, of which Proteobacteria and Acidobacteria were the most abundant groups over time. Moreover, at the initial stages of decay, Proteobacteria were the most abundant whereas Acidobacteria were the most common at advanced stages of decay. Treatment with P. Gigantea led to significant increase of the genus Acidobacteria-Gp1 at 1 year after treatment. The analysis of observed and estimated operational taxonomic units (OTUs) as well as diversity indices revealed that P. Gigantea treatment significantly decreased the initial bacterial richness in the stumps, but the bacterial community gradually recovered and the negative effects of P. Gigantea was attenuated. These results provide additional insight on the risk assessment as well as environmental impact on the long-term use of P. Gigantea in the control of Heterobasidion root rot in conifer forests.
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Response of living tissues of Pinus sylvestris to the saprotrophic biocontrol fungus Phlebiopsis Gigantea
Tree physiology, 2011Co-Authors: Hui Sun, Lars Paulin, Edward Alatalo, Fred O. AsiegbuAbstract:The saprotrophic fungus Phlebiopsis Gigantea has been used for several years as a biocontrol agent against the conifer pathogen Heterobasidion annosum. Although the effectiveness of P. Gigantea in biocontrol has been shown empirically, the long-term effect on living conifer trees as well as the mechanism underlying its antagonistic activity is still unknown. An additional concern is the potential of P. Gigantea to acquire a necrotrophic habit through adaptation to living wood tissues. By using a combination of histochemical, molecular and transcript profiling (454 sequencing), we investigated under in vitro conditions the necrotrophic capability of P. Gigantea and induced localized resistance as a mechanism for its biocontrol action. Pinus sylvestris seedlings (10 years old) were challenged on the xylem surface with P. Gigantea or H. annosum. Both fungi provoked strong necrotic lesions, but after prolonged incubation, P. Gigantea lesions shrank and ceased to expand further. Tree seedlings pre-treated with P. Gigantea further restricted H. annosum-induced necrosis and had more lignified cells. The 454 sequencing revealed elevated transcript levels of genes important for lignification, cell death regulation and jasmonic acid signalling. The results suggest that induced localized resistance is a contributory factor for the biocontrol efficacy of P. Gigantea, and it has a limited necrotrophic capability compared with H. annosum.
Kemal Yildiz - One of the best experts on this subject based on the ideXlab platform.
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Morphological and Palynological Investigation on Silene Gigantea L. var. Gigantea and Silene behen L. (Caryophyllaceae) Distributed in Western Anatolia and Northern Cyprus
Turkish Journal of Botany, 2006Co-Authors: Kemal YildizAbstract:A comparative investigation was carried out on the morphology and palynology of Silene Gigantea L. var. Gigantea and Silene behen L. species of the family Caryophyllaceae distributed in Western Anatolia and Northern Cyprus. An examination conducted on S. Gigantea var. Gigantea revealed that the calyx length in Western Anatolian specimens was shorter than that of those from Northern Cyprus, that the basal petal blades of the Western Anatolian specimens did not have any ligula while those from Northern Cyprus did, and that the petal blades belonging to the specimens from Northern Cyprus demonstrated less clefting as compared to those from Western Anatolia. Therefore, S. Gigantea, growing in Western Anatolia and Northern Cyprus, could be separated into 2 subspecies. In addition, S. behen also could be separated into 2 subspecies. It was also observed that the seeds taken from all specimens of both species were reniform, with the tubercles on the seed surfaces of the S. behen species having a longer conical structure as compared to those of S. Gigantea var. Gigantea. Pollen grains of both species are spheroidal, tectate and spinulose-microperforate. It was also determined that S. Gigantea var. Gigantea specimens collected from Northern Cyprus had greater pore diameters, whereas S. behen specimens from Western Anatolia had greater distances between the pores.
