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Alistair H Bishop - One of the best experts on this subject based on the ideXlab platform.
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multiple locus sequence typing analysis of bacillus thuringiensis recovered from the phylloplane of clover Trifolium hybridum in vegetative form
Microbial Ecology, 2008Co-Authors: M F Bizzarri, A. Prabhakar, Alistair H BishopAbstract:The chromosomal genotype, as judged by multi locus sequence typing, and the episomal genotype, as judged by plasmid profile and cry gene content, were analyzed for a collection of strains of Bacillus thuringiensis. These had been recovered in vegetative form over a period of several months from the leaves of a small plot of clover (Trifolium hybridum). A clonal population structure was indicated, although greater variation in sequence types (STs) was discovered than in previous collections of B. cereus/B. thuringiensis. Isolates taken at the same time had quite different genotypes, whereas those of identical genotypes were recovered at different times. The profiles of plasmid content and cry genes generally bore no relation to each other nor to the STs. Evidently, although relatively little recombination was occurring in the seven chromosomal genes analyzed, a great deal of conjugal transfer, and perhaps recombination, was occurring involving plasmids. A clinical diarrheal isolate of B. cereus and the commercial biopesticide strain HD-1 of B. thuringiensis, both included as out-groups, were found to have very similar STs. This further emphasizes the role of episomal elements in the characteristics and differentiation of these two species.
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recovery of bacillus thuringiensis in vegetative form from the phylloplane of clover Trifolium hybridum during a growing season
Journal of Invertebrate Pathology, 2007Co-Authors: M F Bizzarri, Alistair H BishopAbstract:Abstract Two media were developed which specifically allow the cultivation of Bacillus thuringiensis while it is in the vegetative as opposed to the spore form. Using these media B. thuringiensis was shown conclusively for the first time to exist in an active form on the phylloplane. The profile of its appearance in vegetative and spore form was followed over a growing season on clover (Trifolium hybridum) in the field. Three simultaneous and sudden rises and declines of both spore and vegetative cell densities were observed. The most common other spore-former on these leaves was Bacillus cereus but the fluctuations in appearance of these two very closely related species were not co-incident. Using specific PCR primers a considerable diversity of cry toxin gene types was found in isolates that had been recovered in vegetative form (‘vegetative isolates’) with the majority possessing multiple δ-endotoxin genes while some had only one of those tested. Bioassays against a lepidopteran insect of purified δ-endotoxins showed that they were no more potent than those from a laboratory-adapted strain. PCR primers for an internal region of the vip3A gene produced amplification in 70% of the vegetative isolates compared to 25% of the laboratory-adapted strains tested.
M F Bizzarri - One of the best experts on this subject based on the ideXlab platform.
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multiple locus sequence typing analysis of bacillus thuringiensis recovered from the phylloplane of clover Trifolium hybridum in vegetative form
Microbial Ecology, 2008Co-Authors: M F Bizzarri, A. Prabhakar, Alistair H BishopAbstract:The chromosomal genotype, as judged by multi locus sequence typing, and the episomal genotype, as judged by plasmid profile and cry gene content, were analyzed for a collection of strains of Bacillus thuringiensis. These had been recovered in vegetative form over a period of several months from the leaves of a small plot of clover (Trifolium hybridum). A clonal population structure was indicated, although greater variation in sequence types (STs) was discovered than in previous collections of B. cereus/B. thuringiensis. Isolates taken at the same time had quite different genotypes, whereas those of identical genotypes were recovered at different times. The profiles of plasmid content and cry genes generally bore no relation to each other nor to the STs. Evidently, although relatively little recombination was occurring in the seven chromosomal genes analyzed, a great deal of conjugal transfer, and perhaps recombination, was occurring involving plasmids. A clinical diarrheal isolate of B. cereus and the commercial biopesticide strain HD-1 of B. thuringiensis, both included as out-groups, were found to have very similar STs. This further emphasizes the role of episomal elements in the characteristics and differentiation of these two species.
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recovery of bacillus thuringiensis in vegetative form from the phylloplane of clover Trifolium hybridum during a growing season
Journal of Invertebrate Pathology, 2007Co-Authors: M F Bizzarri, Alistair H BishopAbstract:Abstract Two media were developed which specifically allow the cultivation of Bacillus thuringiensis while it is in the vegetative as opposed to the spore form. Using these media B. thuringiensis was shown conclusively for the first time to exist in an active form on the phylloplane. The profile of its appearance in vegetative and spore form was followed over a growing season on clover (Trifolium hybridum) in the field. Three simultaneous and sudden rises and declines of both spore and vegetative cell densities were observed. The most common other spore-former on these leaves was Bacillus cereus but the fluctuations in appearance of these two very closely related species were not co-incident. Using specific PCR primers a considerable diversity of cry toxin gene types was found in isolates that had been recovered in vegetative form (‘vegetative isolates’) with the majority possessing multiple δ-endotoxin genes while some had only one of those tested. Bioassays against a lepidopteran insect of purified δ-endotoxins showed that they were no more potent than those from a laboratory-adapted strain. PCR primers for an internal region of the vip3A gene produced amplification in 70% of the vegetative isolates compared to 25% of the laboratory-adapted strains tested.
Anna Stochmal - One of the best experts on this subject based on the ideXlab platform.
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Isolation and Structural Determination of Triterpenoid Glycosides from the Aerial Parts of Alsike Clover (Trifolium hybridum L.)
2016Co-Authors: Andy J. Pérez, Mariusz Kowalczyk, Ana M. Simonet, Wieslaw Oleszek, Francisco A. Macías, Anna StochmalAbstract:Five azukisapogenol glycosides (1–5) have been isolated from the aerial parts of alsike clover (Trifolium hybridum L.), and their structures were elucidated by combined spectroscopic, spectrometric (1D and 2D NMR; HRESIMS, ESI–MS/MS), and chemical methods. Three of them are new compounds and were identified as 3-O-[-α-l-arabinopyranosyl(1→2)]-β-d-glucuronopyranosyl azukisapogenol (1), 3-O-[-β-d-glucuronopyranosyl(1→2)-β-d-glucuronopyranosyl]-29-O-β-d-glucopyranosyl azukisapogenol (2), and 3-O-[-α-l-arabinopyranosyl(1→2)-β-d-glucuronopyranosyl]-29-O-β-d-glucopyranosyl azukisapogenol (3). The remaining two (4, 5) are known compounds but have not been previously described as saponins constituents of the genus Trifolium. Also, azukisapogenol is reported here as a triterpenoid aglycone for the first time in this genus. Finally, the main chemotaxonomic features that may be recognized as specific of Trifolium species were discussed
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Biological activity of clovers - free radical scavenging ability and antioxidant action of six Trifolium species.
Pharmaceutical biology, 2014Co-Authors: Joanna Kolodziejczyk-czepas, Pawel Nowak, Iwona Kowalska, Anna StochmalAbstract:AbstractContext: Clovers were chosen on the basis of traditional medicine recommendations, agricultural value, or available information on their promising chemical profiles.Objective: This study evaluates and compares free radical scavenging and antioxidant properties of six clover species: Trifolium alexandrinum L. (Leguminosae), Trifolium fragiferum L., Trifolium hybridum L., Trifolium incarnatum L., Trifolium resupinatum var. majus Boiss., and Trifolium resupinatum var. resupinatum L.Materials and methods: Free radical scavenging activity of the extracts (1.5–50 µg/ml) was estimated by reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic) acid (ABTS•) radicals. The Trifolium extract effects on total antioxidant capacity of blood plasma were determined by the reduction of ABTS•+ and DPPH• radicals, as well as with the use of the ferric reducing ability of plasma (FRAP) assay.Results: The UPLC analysis of chemical profiles of the examined extracts showed...
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Isolation and structural determination of triterpenoid glycosides from the aerial parts of alsike clover (Trifolium hybridum L.).
Journal of agricultural and food chemistry, 2013Co-Authors: Andy J. Pérez, Mariusz Kowalczyk, Ana M. Simonet, Francisco A. Macías, Wieslaw Oleszek, Anna StochmalAbstract:Five azukisapogenol glycosides (1–5) have been isolated from the aerial parts of alsike clover (Trifolium hybridum L.), and their structures were elucidated by combined spectroscopic, spectrometric...
A. G. Todd - One of the best experts on this subject based on the ideXlab platform.
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The Impact of Underseeding Barley (Hordeum vulgare L.) on Timothy (Phleum pratense L.)-Clover (Trifolium pratense L.; Trifolium hybridum L.) Forage Production in a Cool Maritime Climate
Journal of Agronomy and Crop Science, 2003Co-Authors: D. Spaner, A. G. ToddAbstract:Growing barley (Hordeum vulgare L.) in the year of forage establishment is a common agronomic practice in marginal growing regions, but is often not recommended to growers. We examined the effect of silage barley production over an establishing timothy (Phleum pratense L.)-clover (Trifolium pratense L.; Trifolium hybridum L.) forage sward in a 4-year study near St. John's, Newfoundland, Canada. The experiment compared two barley varieties differing in plant height (semidwarf Chapais and Leger), three barley seeding rates and the effect of a forage understorey on forage (barley) production in the establishment year and forage (timothy-clover) production in the subsequent year. The taller Leger yielded similar forage biomass to Chapais in the year of forage establishment, which (when planted at 375 plants m -2 ) was roughly twice that of a pure-stand timothy-clover mix. Increasing the barley seeding rate from 125 to 375 plants m -2 resulted in a linear increase in forage yield in the year of planting. The production of barley forage in the establishment year resulted in reduced timothy-clover forage yield in the year following barley planted at 125 and 375 seeds m -2 , but not for barley planted at 250 seeds m -2 . Companion planting also altered forage species composition in that higher barley seeding rates resulted in 12-18 % less timothy and 2-4 % lower fibre levels in the year following planting. Barley seeded at rates of 250-375 seeds m -2 and undersown with a timothy-clover mixture (harvested at midmilk) resulted in greater forage yield of poorer quality than pure-stand timothy-clover in the planting year, and a barley seeding rate of 250 seeds m -2 did not impede forage production in the subsequent year.
Johannes Forkman - One of the best experts on this subject based on the ideXlab platform.
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Yield and stability of yield of single- and multi-clover grass-clover swards in two contrasting temperate environments
Grass and Forage Science, 2009Co-Authors: Bodil E. Frankow-lindberg, Magnus Halling, Mats Höglind, Johannes ForkmanAbstract:Diversity of clovers in grass-clover swards may contribute to greater herbage yields and stability of yield. This possible effect was evaluated in an experiment carried out over three harvest years at two contrasting sites, differing in precipitation and soil composition, using mixed swards containing either one, two or three clover species sown together with timothy (Phleum pratense L.) and meadow fescue (Festuca pratensis L.). The clover species were red clover (Trifolium pratense L.), white clover (Trifolium repens L.) and alsike clover (Trifolium hybridum L.) sown in various proportions in a total of ten treatments. All swards were fertilized with nitrogen with amounts that increased from year to year, and three harvests were taken in three consecutive years. There was a significant interaction between site and species mixture on total dry matter (DM) yields (range 27–32 tonnes ha−1) and DM yields of clovers (range 5–15 tonnes ha−1); red clover as a single species or in a mixture was superior at the dry site while multi-clover species mixtures were superior at the wet site. Alsike clover was the least productive species of clover. Stability of yield of clovers was generally higher by including white and red clover in the seed mixture but total DM yield was not.
