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1
Hendy, Justin. "A MORPHOLOGICAL ANALYSIS OF THE TRIFOLIUM AMABILE KUNTH SPECIES COMPLEX IN SOUTH AMERICA." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1376064759.
Texto completo da fonte
2
Bjourson, Anthony John. "Early plant gene expression in the Trifolium repens-Rhizobium leguminosarum Bv. Trifolii symbiosis." Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318876.
Texto completo da fonte
3
au, ronald yates@agric wa gov, and Ronald John Yates. "Symbiotic Interactions of Geographically Diverse Annual and Perennial Trifolium spp. with Rhizobium leguminosarum bv. trifolii." Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20100330.93305.
Texto completo da fonteResumo:
Perennial clovers are being evaluated for their potential to reduce groundwater levels in Australian cropping zones where many soils are considered too acidic for reliable lucerne nodulation. However, the release of effective inocula for perennial clovers into such areas where sub clover is the predominant legume, could potentially compromise nitrogen fixation from this valuable annual clover if the symbiosis between the new inoculants and sub clover is not optimal. Studies were therefore designed to increase our understanding of these symbiotic interactions to optimise the management of legume-rhizobia interactions to extend (rather than restrict) the use of legumes in new environments.
To assist the understanding of interactions between clovers and their microsymbionts, a glasshouse-based study of the cross-inoculation characteristics of 38 strains of Rhizobium leguminosarum biovar trifolii (R. l. trifolii) associated with 38 genotypes of annual and perennial Trifolium spp. from world centres of diversity was undertaken. Rhizobial isolates and clovers were assembled from South and equatorial Africa, North and South America and the Euro-Mediterranean regions. There was substantial specificity amongst the African clovers for effective nodulation. No strain of rhizobia from the South American perennial T. polymorphum, or from the Ethiopian clovers, was able to nodulate sub clover effectively, whilst less than 33% of the 18 strains from these regions could form nodules with the less promiscuous Mediterranean annual T. glanduliferum. Seventy of 476 cross-inoculation treatments examined did not nodulate, whilst 81 treatments clearly demonstrated effective nodulation. The remainder of the crossinoculation pairings revealed only partially effective or ineffective nodulation. Two barriers to effective nodulation were identified from the cross- inoculation study: a geographic barrier representing the broad centres of clover diversity, across which few host- strain combinations were effective; and within each region, a significant barrier to effective nodulation between an isolate from an annual host on a perennial host, or vice versa. Clovers and their rhizobia from within the Euro-Mediterranean region of diversity were more able to overlap the annual/perennial barrier than genotypes from the other regions. The data indicate that it will be a substantial challenge to develop inocula for perennial clovers that do not adversely affect nitrogen fixation by sub clover and other annual clovers in commerce, especially if the perennial clovers originate from Africa or America.
To investigate the management of legume-rhizobia interactions when introducing legumes into new environments, a study was initiated in Uruguay (Mediterranean annual clovers were introduced into a predominantly perennial clover setting) that could be considered opposite to the situation emerging within southern Australia (perennial clovers evaluated in a predominantly annual clover setting). The Uruguayan grasslands contain populations of indigenous R. l. trifolii that nodulate endemic T. polymorphum but form ineffective nodules on clovers originating from the Mediterranean region. Importantly in the Uruguayan setting, Government policy has facilitated the introduction of numerous varieties of annual Mediterranean clovers with the aim of improving overall winter production in their naturally managed grasslands. In an attempt to understand the rhizobial ecology of this scenario, a cross-row experiment was set-up in 1999 in a basaltic, acid soil in Glencoe, Uruguay, to follow the survival and symbiotic performance of nine exotic strains of R. l. trifolii. In this thesis I report on the ability of the introduced strains to compete for nodule occupancy of Mediterranean clover hosts and show the impacts of the introduced strains on the productivity of the indigenous Uruguayan clover, T. polymorphum. Of the introduced strains, WSM1325 was a superior inoculant and remained highly persistent and competitive in forming effective symbioses with the Mediterranean hosts, T. purpureum and T. repens, in the Uruguayan environment over a 3 year period. T. purpureum and T. repens, when inoculated with the introduced strains, did not nodulate with any indigenous R. l. trifolii as typed from nodules of T. polymorphum. Conversely, there were no nodules on the Uruguayan host T. polymorphum that contained the introduced R. l. trifolii. These results revealed that there were effective symbioses between strains of R. l. trifolii and clovers, even though the soil contained ineffective R. l. trifolii for all hosts. This represents the first reported example of selective nodulation for an effective symbiosis in situ with annual and perennial clovers in acid soils. This phenomenon raised the question of whether this was restricted to the particular edaphic scenario in Glencoe, Uruguay.
Glasshouse-based experiments in Australia were conducted to further understand the selection phenomenon. Two strains were selected for comparisons; strain WSM1325 isolated from an annual clover in the Mediterranean and WSM2304 isolated from the perennial clover T. polymorphum in Uruguay, South America. Variables that may have been specific to Glencoe were investigated. Thus, the effect of cell density and strain ratio at the time of inoculation, as well as soil pH, were examined on the two hosts (T. purpureum and T. polymorphum). Each was exposed to the same effective and ineffective micro-symbionts. In co-inoculation experiments at a cell density of 104 cells mL-1, each host nodulated solely with its effective strain, even when this strain was out-numbered 100:1 by the ineffective strain. However, the selection process ceased when the effective strain was out-numbered 1000:1. At higher basal cell concentrations of 105 - 108 cells mL-1, selection for WSM1325 to form effective nodules on T. purpureum was evident, but was significantly reduced as the ratio of ineffective cells in the inoculum increased above 4-fold. These results indicate that the selection mechanism is highly dependent upon the basal rhizobial cell density. Soil pH did not significantly alter the process, which could not be simply explained by the rate of strain growth, or extent of nodulation.
Greater precision was sought in the terminology applied to nodulation outcomes where legumes have a choice of micro-symbiotic partners from within the same species of root-nodule bacteria. The nominated preferred terms are nonselective, exclusive, and selective nodulation.
In view of the difference in host range between WSM1325 and WSM2304 and the selective nodulation process, a preliminary investigation into the genetic backgrounds of WSM1325 and WSM2304 was conducted. A selected range of gene regions were amplified by PCR from each strain and sequenced. Comparative analysis of the nucleotide sequences revealed that although the 16S rRNA sequences were identical, the atpD, GSII and nodD sequences contained
distinct differences revealing disparity between the pSym replicons and between the chromosomal replicons of these strains. Of the genes sequenced, the highest degree of divergence was noted for the symbiotic NodD protein products, which are known to be critical determinants in the nodulation of specific hosts. An examination of the nodD gene region of WSM1325 and WSM2304 revealed a further contrasting feature; the regulatory gene nodR was present in the nodD gene region of WSM1325 but absent in WSM2304. Since NodR is known to be required for adding highly unsaturated fatty acyl groups onto the Nod-factor backbone, I could now hypothesise that the nodulation incompatibility observed between Trifolium hosts and micro-symbionts obtained from different geographical locations may result from differences in Nod-factor decoration. With the full genome sequence of the two strains WSM1325 and WSM2304 soon to be available, the role of nodR and any link to the selection phenomenon described in this thesis can be addressed.
4
DELCLOS, BERTRAND. "Etude de la resistance a sclerotinia trifoliorum chez le trefle violet (trifolium pratense l. )." Paris 11, 1996. http://www.theses.fr/1996PA112376.
Texto completo da fonteResumo:
Dans toute l'hemisphere nord, la sclerotiniose due au champignon ascomycete sclerotinia trifoliorum eriks, est la principale maladie fongique touchant le trefle violet (trifolium pratense l. ). Les pratiques culturales et l'emploi de fongicides n'etant pas totalement efficaces et souvent trop couteux, la creation de cultivars resistants a la sclerotiniose s'impose comme l'element majeur pour une lutte integree. Afin de definir les meilleures methodes de selection pour ce caractere, nous avons etudie cette interaction hote/pathogene sous l'angle de la genetique vegetale. Au prealable, nous avons mis au point un test pathologique en conditions controlees permettant d'evaluer de maniere simple, fiable et peu couteuse le niveau de resistance de genotypes et de cultivars. Il consiste a inoculer des folioles detachees par des ascospores de s. Trifoliorum produites au laboratoire. Nous l'avons employe pour etudier l'heredite de la resistance a travers cinq dialleles (4 x 4) deconnectes et de deux cycles de selection divergente sur des trefles diploides. L'effet de la ploidie sur l'expression de la resistance a ensuite ete envisage. Enfin, des marqueurs biochimiques (isoflavonoides reveles en hplc) et moleculaires (rapd isoles par une analyse en segregation) ont ete mis en relation avec le niveau de resistance. Ces etudes ont souligne l'importance de l'aptitude generale a la combinaison (agc), les effets additifs etant predominants dans l'expression de la variabilite genetique de la resistance. L'heritabilite en resultant s'est averee assez elevee (comprise entre 0,50 et 0,70) mais grandement affectee par la selection pour la resistance. De plus, nous avons montre que la tetraploidie accroit globalement le niveau de resistance. Cependant, l'effet de la ploidie interagit fortement avec le fond genetique. En conclusion, nous avons acquis une meilleure connaissance de la genetique de la resistance a la sclerotiniose chez le trefle violet nous permettant d'envisager des methodes de selection efficaces integrant les outils que nous avons developpes: test pathologique, marqueurs rapd, populations ameliorees
5
Ahlquist, Tia Kay. "A Morphological Analysis of the Trifolium amabile Kunth Species Complex in North America." Miami University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=miami1355423537.
Texto completo da fonte
6
Yates, Ronald John. "Symbiotic interactions of geographically diverse annual and perennial Trifolium spp. with Rhizobium leguminosarum bv. trifolii /." Murdoch University Digital Theses Program, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20100330.93305.
Texto completo da fonte
7
Yates, Ronald. "Symbiotic Interactions of Geographically Diverse Annual and Perennial Trifolium spp. with Rhizobium leguminosarum bv. trifolii." Thesis, Yates, Ronald (2008) Symbiotic Interactions of Geographically Diverse Annual and Perennial Trifolium spp. with Rhizobium leguminosarum bv. trifolii. PhD thesis, Murdoch University, 2008. https://researchrepository.murdoch.edu.au/id/eprint/1699/.
Texto completo da fonteResumo:
Perennial clovers are being evaluated for their potential to reduce groundwater levels in Australian cropping zones where many soils are considered too acidic for reliable lucerne nodulation. However, the release of effective inocula for perennial clovers into such areas where sub clover is the predominant legume, could potentially compromise nitrogen fixation from this valuable annual clover if the symbiosis between the new inoculants and sub clover is not optimal. Studies were therefore designed to increase our understanding of these symbiotic interactions to optimise the management of legume-rhizobia interactions to extend (rather than restrict) the use of legumes in new environments.
To assist the understanding of interactions between clovers and their microsymbionts, a glasshouse-based study of the cross-inoculation characteristics of 38 strains of Rhizobium leguminosarum biovar trifolii (R. l. trifolii) associated with 38 genotypes of annual and perennial Trifolium spp. from world centres of diversity was undertaken. Rhizobial isolates and clovers were assembled from South and equatorial Africa, North and South America and the Euro-Mediterranean regions. There was substantial specificity amongst the African clovers for effective nodulation. No strain of rhizobia from the South American perennial T. polymorphum, or from the Ethiopian clovers, was able to nodulate sub clover effectively, whilst less than 33% of the 18 strains from these regions could form nodules with the less promiscuous Mediterranean annual T. glanduliferum. Seventy of 476 cross-inoculation treatments examined did not nodulate, whilst 81 treatments clearly demonstrated effective nodulation. The remainder of the crossinoculation pairings revealed only partially effective or ineffective nodulation. Two barriers to effective nodulation were identified from the cross- inoculation study: a geographic barrier representing the broad centres of clover diversity, across which few host- strain combinations were effective; and within each region, a significant barrier to effective nodulation between an isolate from an annual host on a perennial host, or vice versa. Clovers and their rhizobia from within the Euro-Mediterranean region of diversity were more able to overlap the annual/perennial barrier than genotypes from the other regions. The data indicate that it will be a substantial challenge to develop inocula for perennial clovers that do not adversely affect nitrogen fixation by sub clover and other annual clovers in commerce, especially if the perennial clovers originate from Africa or America.
To investigate the management of legume-rhizobia interactions when introducing legumes into new environments, a study was initiated in Uruguay (Mediterranean annual clovers were introduced into a predominantly perennial clover setting) that could be considered opposite to the situation emerging within southern Australia (perennial clovers evaluated in a predominantly annual clover setting). The Uruguayan grasslands contain populations of indigenous R. l. trifolii that nodulate endemic T. polymorphum but form ineffective nodules on clovers originating from the Mediterranean region. Importantly in the Uruguayan setting, Government policy has facilitated the introduction of numerous varieties of annual Mediterranean clovers with the aim of improving overall winter production in their naturally managed grasslands. In an attempt to understand the rhizobial ecology of this scenario, a cross-row experiment was set-up in 1999 in a basaltic, acid soil in Glencoe, Uruguay, to follow the survival and symbiotic performance of nine exotic strains of R. l. trifolii. In this thesis I report on the ability of the introduced strains to compete for nodule occupancy of Mediterranean clover hosts and show the impacts of the introduced strains on the productivity of the indigenous Uruguayan clover, T. polymorphum. Of the introduced strains, WSM1325 was a superior inoculant and remained highly persistent and competitive in forming effective symbioses with the Mediterranean hosts, T. purpureum and T. repens, in the Uruguayan environment over a 3 year period. T. purpureum and T. repens, when inoculated with the introduced strains, did not nodulate with any indigenous R. l. trifolii as typed from nodules of T. polymorphum. Conversely, there were no nodules on the Uruguayan host T. polymorphum that contained the introduced R. l. trifolii. These results revealed that there were effective symbioses between strains of R. l. trifolii and clovers, even though the soil contained ineffective R. l. trifolii for all hosts. This represents the first reported example of selective nodulation for an effective symbiosis in situ with annual and perennial clovers in acid soils. This phenomenon raised the question of whether this was restricted to the particular edaphic scenario in Glencoe, Uruguay.
Glasshouse-based experiments in Australia were conducted to further understand the selection phenomenon. Two strains were selected for comparisons; strain WSM1325 isolated from an annual clover in the Mediterranean and WSM2304 isolated from the perennial clover T. polymorphum in Uruguay, South America. Variables that may have been specific to Glencoe were investigated. Thus, the effect of cell density and strain ratio at the time of inoculation, as well as soil pH, were examined on the two hosts (T. purpureum and T. polymorphum). Each was exposed to the same effective and ineffective micro-symbionts. In co-inoculation experiments at a cell density of 104 cells mL-1, each host nodulated solely with its effective strain, even when this strain was out-numbered 100:1 by the ineffective strain. However, the selection process ceased when the effective strain was out-numbered 1000:1. At higher basal cell concentrations of 105 - 108 cells mL-1, selection for WSM1325 to form effective nodules on T. purpureum was evident, but was significantly reduced as the ratio of ineffective cells in the inoculum increased above 4-fold. These results indicate that the selection mechanism is highly dependent upon the basal rhizobial cell density. Soil pH did not significantly alter the process, which could not be simply explained by the rate of strain growth, or extent of nodulation.
Greater precision was sought in the terminology applied to nodulation outcomes where legumes have a choice of micro-symbiotic partners from within the same species of root-nodule bacteria. The nominated preferred terms are “nonselective”, “exclusive”, and “selective” nodulation.
In view of the difference in host range between WSM1325 and WSM2304 and the selective nodulation process, a preliminary investigation into the genetic backgrounds of WSM1325 and WSM2304 was conducted. A selected range of gene regions were amplified by PCR from each strain and sequenced. Comparative analysis of the nucleotide sequences revealed that although the 16S rRNA sequences were identical, the atpD, GSII and nodD sequences contained distinct differences revealing disparity between the pSym replicons and between the chromosomal replicons of these strains. Of the genes sequenced, the highest degree of divergence was noted for the symbiotic NodD protein products, which are known to be critical determinants in the nodulation of specific hosts. An examination of the nodD gene region of WSM1325 and WSM2304 revealed a further contrasting feature; the regulatory gene nodR was present in the nodD gene region of WSM1325 but absent in WSM2304. Since NodR is known to be required for adding highly unsaturated fatty acyl groups onto the Nod-factor backbone, I could now hypothesise that the nodulation incompatibility observed between Trifolium hosts and micro-symbionts obtained from different geographical locations may result from differences in Nod-factor decoration. With the full genome sequence of the two strains WSM1325 and WSM2304 soon to be available, the role of nodR and any link to the selection phenomenon described in this thesis can be addressed.
8
Yates, Ronald. "Symbiotic Interactions of Geographically Diverse Annual and Perennial Trifolium spp. with Rhizobium leguminosarum bv. trifolii." Yates, Ronald (2008) Symbiotic Interactions of Geographically Diverse Annual and Perennial Trifolium spp. with Rhizobium leguminosarum bv. trifolii. PhD thesis, Murdoch University, 2008. http://researchrepository.murdoch.edu.au/1699/.
Texto completo da fonteResumo:
Perennial clovers are being evaluated for their potential to reduce groundwater levels in Australian cropping zones where many soils are considered too acidic for reliable lucerne nodulation. However, the release of effective inocula for perennial clovers into such areas where sub clover is the predominant legume, could potentially compromise nitrogen fixation from this valuable annual clover if the symbiosis between the new inoculants and sub clover is not optimal. Studies were therefore designed to increase our understanding of these symbiotic interactions to optimise the management of legume-rhizobia interactions to extend (rather than restrict) the use of legumes in new environments.
To assist the understanding of interactions between clovers and their microsymbionts, a glasshouse-based study of the cross-inoculation characteristics of 38 strains of Rhizobium leguminosarum biovar trifolii (R. l. trifolii) associated with 38 genotypes of annual and perennial Trifolium spp. from world centres of diversity was undertaken. Rhizobial isolates and clovers were assembled from South and equatorial Africa, North and South America and the Euro-Mediterranean regions. There was substantial specificity amongst the African clovers for effective nodulation. No strain of rhizobia from the South American perennial T. polymorphum, or from the Ethiopian clovers, was able to nodulate sub clover effectively, whilst less than 33% of the 18 strains from these regions could form nodules with the less promiscuous Mediterranean annual T. glanduliferum. Seventy of 476 cross-inoculation treatments examined did not nodulate, whilst 81 treatments clearly demonstrated effective nodulation. The remainder of the crossinoculation pairings revealed only partially effective or ineffective nodulation. Two barriers to effective nodulation were identified from the cross- inoculation study: a geographic barrier representing the broad centres of clover diversity, across which few host- strain combinations were effective; and within each region, a significant barrier to effective nodulation between an isolate from an annual host on a perennial host, or vice versa. Clovers and their rhizobia from within the Euro-Mediterranean region of diversity were more able to overlap the annual/perennial barrier than genotypes from the other regions. The data indicate that it will be a substantial challenge to develop inocula for perennial clovers that do not adversely affect nitrogen fixation by sub clover and other annual clovers in commerce, especially if the perennial clovers originate from Africa or America.
To investigate the management of legume-rhizobia interactions when introducing legumes into new environments, a study was initiated in Uruguay (Mediterranean annual clovers were introduced into a predominantly perennial clover setting) that could be considered opposite to the situation emerging within southern Australia (perennial clovers evaluated in a predominantly annual clover setting). The Uruguayan grasslands contain populations of indigenous R. l. trifolii that nodulate endemic T. polymorphum but form ineffective nodules on clovers originating from the Mediterranean region. Importantly in the Uruguayan setting, Government policy has facilitated the introduction of numerous varieties of annual Mediterranean clovers with the aim of improving overall winter production in their naturally managed grasslands. In an attempt to understand the rhizobial ecology of this scenario, a cross-row experiment was set-up in 1999 in a basaltic, acid soil in Glencoe, Uruguay, to follow the survival and symbiotic performance of nine exotic strains of R. l. trifolii. In this thesis I report on the ability of the introduced strains to compete for nodule occupancy of Mediterranean clover hosts and show the impacts of the introduced strains on the productivity of the indigenous Uruguayan clover, T. polymorphum. Of the introduced strains, WSM1325 was a superior inoculant and remained highly persistent and competitive in forming effective symbioses with the Mediterranean hosts, T. purpureum and T. repens, in the Uruguayan environment over a 3 year period. T. purpureum and T. repens, when inoculated with the introduced strains, did not nodulate with any indigenous R. l. trifolii as typed from nodules of T. polymorphum. Conversely, there were no nodules on the Uruguayan host T. polymorphum that contained the introduced R. l. trifolii. These results revealed that there were effective symbioses between strains of R. l. trifolii and clovers, even though the soil contained ineffective R. l. trifolii for all hosts. This represents the first reported example of selective nodulation for an effective symbiosis in situ with annual and perennial clovers in acid soils. This phenomenon raised the question of whether this was restricted to the particular edaphic scenario in Glencoe, Uruguay.
Glasshouse-based experiments in Australia were conducted to further understand the selection phenomenon. Two strains were selected for comparisons; strain WSM1325 isolated from an annual clover in the Mediterranean and WSM2304 isolated from the perennial clover T. polymorphum in Uruguay, South America. Variables that may have been specific to Glencoe were investigated. Thus, the effect of cell density and strain ratio at the time of inoculation, as well as soil pH, were examined on the two hosts (T. purpureum and T. polymorphum). Each was exposed to the same effective and ineffective micro-symbionts. In co-inoculation experiments at a cell density of 104 cells mL-1, each host nodulated solely with its effective strain, even when this strain was out-numbered 100:1 by the ineffective strain. However, the selection process ceased when the effective strain was out-numbered 1000:1. At higher basal cell concentrations of 105 - 108 cells mL-1, selection for WSM1325 to form effective nodules on T. purpureum was evident, but was significantly reduced as the ratio of ineffective cells in the inoculum increased above 4-fold. These results indicate that the selection mechanism is highly dependent upon the basal rhizobial cell density. Soil pH did not significantly alter the process, which could not be simply explained by the rate of strain growth, or extent of nodulation.
Greater precision was sought in the terminology applied to nodulation outcomes where legumes have a choice of micro-symbiotic partners from within the same species of root-nodule bacteria. The nominated preferred terms are “nonselective”, “exclusive”, and “selective” nodulation.
In view of the difference in host range between WSM1325 and WSM2304 and the selective nodulation process, a preliminary investigation into the genetic backgrounds of WSM1325 and WSM2304 was conducted. A selected range of gene regions were amplified by PCR from each strain and sequenced. Comparative analysis of the nucleotide sequences revealed that although the 16S rRNA sequences were identical, the atpD, GSII and nodD sequences contained distinct differences revealing disparity between the pSym replicons and between the chromosomal replicons of these strains. Of the genes sequenced, the highest degree of divergence was noted for the symbiotic NodD protein products, which are known to be critical determinants in the nodulation of specific hosts. An examination of the nodD gene region of WSM1325 and WSM2304 revealed a further contrasting feature; the regulatory gene nodR was present in the nodD gene region of WSM1325 but absent in WSM2304. Since NodR is known to be required for adding highly unsaturated fatty acyl groups onto the Nod-factor backbone, I could now hypothesise that the nodulation incompatibility observed between Trifolium hosts and micro-symbionts obtained from different geographical locations may result from differences in Nod-factor decoration. With the full genome sequence of the two strains WSM1325 and WSM2304 soon to be available, the role of nodR and any link to the selection phenomenon described in this thesis can be addressed.
9
Babagolzadeh, Ali. "Salinity tolerance in seven Trifolium species." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367195.
Texto completo da fonte
10
Beauregard, Marie-Soleil. "Characterization of rhizobia nodulating Trifolium ambigum M.B." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81246.
Texto completo da fonteResumo:
Phenotypic characterizations demonstrated that diversity among 19 naturalized North American and 5 commercial Kura clover ( Trifolium ambiguum M.B.) rhizobial strains was limited. Growth chamber and field evaluations indicated the superiority of North American isolates, increasing foliage accumulation by 30% when compared to commercial inoculant strains. Nitrogen fertilization, however, produced greater accumulations in all evaluations. Genetic diversity among 128 isolates from the lower Caucasus was significant. Nodulation specificity of rhizobia from the lower Caucasus was demonstrated to be more complex than what was reported in the literature, as plants of different ploidy levels and even of different species were, in some cases, nodulated by the same isolate. Specificity of a given rhizobial strain varied depending on the isolate. This study identified naturalized North American rhizobial isolates that are more efficient than currently used commercial strains and increased the genetic diversity of Kura clover rhizobia currently available.
11
Dettenborn, Greice Raquel. "Investigação de isoflavonas em espécies de leguminosas nativas do sul do Brasil, com ênfase em trifolium riograndense Burkart." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/28520.
Texto completo da fonteResumo:
Isoflavonas são compostos fenólicos de ocorrência principalmente na família Leguminosae, utilizados, entre outros, como alternativa para a reposição hormonal em mulheres no período pós-menopausa, devido a sua ação estrogênica seletiva. Em vista disso, foi investigada a presença das isoflavonas daidzeína, genisteína, formononetina e biochanina A em 153 espécies de Leguminosas nativas do Rio Grande do Sul através de cromatografia líquida de alta eficiência. Destas, 42 espécies apresentaram ao menos uma das quatro isoflavonas investigadas. Pertencente à família Leguminosae, o gênero Trifolium é encontrado em quase toda a zona temperada e subtropical do mundo, sendo que a espécie Trifolium riograndense é nativa do estado do Rio Grande do Sul. As isoflavonas daidzeína, genisteína, formononetina e biochanina A foram quantificadas nesta espécie, que apresentou 0,187 mg de daidzeína; 0,223 mg de genisteína; 16,683 mg de formononetina e 1,207 mg de biochanina A (por grama de amostra seca). A parte da planta com maior concentração de isoflavonas foi a folha, com 7,331 mg por grama de amostra seca, e a parte da planta com menor teor destas isoflavonas foi a raiz, com 2,806 mg por grama de amostra seca. Formononetina foi a isoflavona majoritária em todas as partes da planta analisadas. Ainda, foram realizados ensaios de atividade antiinflamatória do extrato das folhas de Trifolium riograndense. Foram utilizados os modelos de quimiotaxia in vitro em câmara de Boyden e indução de edema em pata de ratos, utilizando a carragenina como agente flogístico. Pelo ensaio de quimiotaxia, verificou-se que o extrato das folhas do trevo em estudo apresentou inibição da migração leucocitária de forma significativa em diversas concentrações testadas. Através do ensaio de edema em pata de rato, verificou-se que a administração por via oral de extrato de Trifolium riograndense em ratos, na dose de 100 mg/kg, inibiu a formação do edema provocado pela carragenina, significativamente.<br>Isoflavones are polyphenolic compounds of Leguminosae Family. They are used as alternative therapy for treating symptoms of the menopause, due their selective action in oestrogenic receptors. So, the presence of isoflavones daidzein, genistein, formononetin and biochanin A was investigated in 153 species of the Leguminosae Family that are natives of South Brazil, by high performance liquid chromatography. Forty two species showed at least one of four investigated isoflavones. The genus Trifolium belongs to Leguminosae Family. It is found in temperate and subtropical regions in the world. Trifolium riograndense is a species native of Rio Grande do Sul – Brazil. The isoflavone content in this species was 0.187 mg g-1 of dry material (DM) to daidzein; 0.223 mg g-1 of DM to genistein; 16.683 mg g-1 of DM to formononetin, and 1.207 mg g-1 of DM to biochanin A. The leaf was the part of the plant with more isoflavone content, 7.331 mg of DM. The root was the part with less isoflavone content, 2.806 mg of DM. The majority isoflavone in all parts was formononetin. The dry extract of leaves of Trifolium riograndense was submitted to biological tests. The anti-inflammatory activity was analyzed by Boyden chamber assay, it allowed observe chemotaxis phenomenon, and by induced rat paw oedema using carrageenan as flogistic agent. Through chemotaxis model, potential activity could be observed to extract of Trifolium riograndense. In the induced rat paw oedema test, a significantly inhibition of oedema was observed in the animals treated with extract of Trifolium riograndense (100 mg/kg).
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Lamont, Emma-Jane. "An ecogeographic survey of Trifolium L. in Turkey." Thesis, University of Birmingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633217.
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Results are presented of an investigation into the biodiversity of Trifolium L. present in the Republic of Turkey The aim of the project is to provide the information required for planning conservation of 0 Turkish Thfolium germplasm both in situ and ex situ. Diversity contained within the genus is investigated at several levels; species distributions, taxonomic relationships between the species, and for selected taxa diversity between populations is investigated. Interactive, computer based identification aids and a traditional dichotomous key to the relevant species are presented. Distributions of the Trifolium species that occur in Turkey were investigated by compiling a set of georeferenced data from a variety of sources. The data were obtained from herbarium labels, donated by genebanks, collected during fieldwork and taken from the literature. A database formed from the merged data sets was used to create species distribution maps. Ecological information contained in the database is summarised in tabulated form species by species giving altitude ranges, habitat descriptions and soil characteristics of the specimen collection sites. Areas are identified from the distribution maps in which few germplasm samples have been collected, and therefore should be prioritised for future germplasm collecting activities. The priority areas include eastern central Anatolia (Sivas, Yozgat and Kayseri provinces), the province of Istanbul, Turkey-in-Europe (particularly Edirne and Kirklareli) and the regions north and south of Ankara. The species richness coefficient for Trifolium species in Turkey is at a maximum in the provinces of Istanbul, Izmir, Mugla, Usak, Hatay and Gaziantep. Extensive germplasm collections have taken place in all these provinces, except Istanbul. Several of the species recorded as occurring in the province of Istanbul are known in Turkey from a very small number of herbarium specimens that were collected in the nineteenth or early twentieth century. Classification of the provinces of Turkey into six ecogeographical regions on the basis of recorded Trifolium species identifies three well defined groups one occurrjng on the Mediterranean and Aegean coasts, another inland in western Turkey and one in eastern Turkey. Many of the provinces that are not included in any of these well-defined clusters have been under-collected for Trifolium. A morphological data set relating to ninety-seven Trifolium species was collected from herbarium specimens and the literature. Species included in the analysis comprise all those that occur in Turkey, which is at the centre of diversity for the genus. The data set was analysed to study infrageneric relationships of Trifolium taxa, and the results'obtained were compared with previously published taxonomies. Generally, species groupings proposed by previous authors were supported by the phenetic analysis. The differences between the clusters obtained in this study and previous taxonomies occurred within sections Trifolium, Chronosemium Ser. and Lotoidea Crantz. Several changes to the division of section Trifolium into subsections and of section Chronosemium into series are suggested. The analysis also indicates that section Lotoidea should be split into at least two sections. Living specimens of thirteen annual species of Trifolium section Trifolium where characterised morphologically. The specimens were raised in a randomised design and were characterised using quantitative traits. All accessions were of Turkish origin. The data are analysed to investigate variation between the test species using multivariate analysis of variance and cluster analysis. The species groupings obtained are discussed with reference to previous taxonomic treatments. Some of the results obtained from the herbarium-based data set are supported. The suggestions that section Trifolium subsection Lappacea should be divided and that T. sylvaticum should be removed from subsection Stellata are supported. Species of subsections Echinata, Squamosa and Clypeata clustered closely together, which agrees with the suggestions that these subsections should be merged. Several populations were raised of each of five Trifolium section Trifolium species, namely T. purpureum, T. echinatum, T. hirtum, T. angustifolium and T. cherleri. The geographic origin is known for most of these populations, and differences between populations with respect to their origins are discussed. Significant differences occurred between almost all populations raised, suggesting that variation between populations is high for these species. An interactive, computer based key to the ninety-seven species of Trifolium L. occurring in Turkey was created. Traditional dichotomous keys constructed using the same data set are also presented. Data were collected from herbarium specimens, living specimens and literature sources. Herbarium specimens were available for all but five of the species. An average of 135 morphological characters was scored per species, including vegetative, flowering and fruiting characters. The data were coded in DELTA format (which has been endorsed by the International Union of Biological Sciences Commission on Taxonomic Databases). This new interactive key has several advantages over traditional dichotomous keys to Trifolium, including limited usage of technical terms, and use of illustrations. In addition, photographic images of more than 80% of the taxa are contained within the interactive key. Full descriptions of the taxa are also available within the key. The interactive key files are available to download from the Institute of Grassland and Environmental Research web site (HTTP://www.igergru.bbsrc.ac.uk/).
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Sanja, Vlaisavljević. "Hemijska, biohemijska i mikrobiološka karakterizacija Trifolium pratense L." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2014. https://www.cris.uns.ac.rs/record.jsf?recordId=87893&source=NDLTD&language=en.
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Hemijska karakterizacija ekstrakata <em>T. pratense </em>L. određena je LC-MS-MS, a etarskih ulja GC-MS analizom, pri čemu je identifikovano više bioaktivnih jedinjenja. Spektrofotometrijskim metodama ispitan je antioksidantni potencijal ekstrakata i etarskih ulja. Hepatoprotektivni efekat određen je na homogenatu i hemolizatu jetre laboratorijskih miševa. Budući da ova biljka ima visok sadržaj izoflavona, određena je estrogena, antiestrogena aktivnost, kao i citotoksičnost ekstrakata. Antimikrobna aktivnosta ekstrakata i etarskih ulja ispitana je na šest bakterijskih sojeva. Ekstrakti i etarska ulja su bili umereno aktivni u pogledu bioloških aktivnosti, osim u slučaju antimikrobne aktivnosti koju nije pokazao nijedan ispitivani uzorak.<br>The chemical characterization of <em>T. pratense</em> extracts was determined by LC-MS-MS, and the essential oils of the GC-MS analysis, wherein the various bioactive compounds were identified. Antioxidant potential of extracts and essential oils was tested by spectrophotometric methods. Hepatoprotective effect was determined in haemolysate and liver homogenate of laboratory mice. Estrogen, antiestrogen activity, as well as the cytotoxicity of the extracts were determined due to the high content of isoflavones. Antimicrobial activity of extracts and essential oils was investigatied on six bacterial strains. Essential oils and extracts were moderately active in terms of biological activity, except in the case of antimicrobial activity where none of the extracts were active against tested bacterial strains.
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Foster, Benjamin George. "A Taxonomic Reevaluation of Trifolium variegatum Nutt. Based on Morphology." Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1437576641.
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Kurantavičius, Vytautas. "Dobilų (Trifolium L.) genties augalų izoflavonų kiekybinės sudėties tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100621_095209-97450.
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Tyrimo objektas ir metodai: dobilų genties augalų lapų, stiebų, žiedų žaliavų tyrimas. Izoflavonai nustatyti ESC metodu.
Darbo tikslas: Atlikti izoflavonų genisteino, formononetino ir daidzeino analizę dobilų genties augaluose, taikant ESC metodą.
Darbo uždaviniai: atlikti literatūros analizę, apibendrinant dobilų (Trifolium L) genties augalų biologines savybes, izoflavonų taikymą gydymo tikslais ir nustatymo metodus. Parinkti ekstrakcijos sąlygas, įvertinant pasirinkto ekstrakcijos tirpiklio, jo poliškumo ir ekstrakcijos laiko įtaką. Optimizuoti ESC metodą dobilų žaliavos tyrimui ir pagrįsti metodo tinkamumą izoflavonų kiekio nustatymui. Atlikti įvairių dobilų rūšių lapų, žiedų, stiebų ir šaknų mėginių analizę optimizuotu ESC metodu ir nustatyti izoflavonų kiekius juose. Įvertinti izoflavonų kiekio įvairavimą skirtingose dobilų rūšyse. Nustatyti izoflavonų kiekybinės sudėties pasiskirstymą augalų dalyse. Palyginti T. pratense izoflavonų kiekių skirtumus augalo dalyse. Palyginti izoflavonų kiekybinės sudėties skirtumus T. pratense kultivuojamų ir laukinės populiacijos augalų žaliavose.
Išvados: atlikus mokslinės literatūros šaltinių analizę, apibendrintos dobilų genties augalų biologinės savybės, izoflavonų taikymas gydymo tikslais ir flavonoidų bei izoflavonoidų nustatymo metodai.
Įvertintas tirpiklio poliškumas ir taikomos ekstrakcijos trukmės įtaka izoflavonų kiekiui. Optimizuotas ESC metodas kiekybinei izoflavonų analizei dobilų (Trifolium L.) genties augalų žaliavoms... [toliau žr. visą tekstą]<br>Object and methods: phytochemical analysis of different parts (leaves, blossoms, roots) of clover genus plants.
Aim: to perform analysis of isoflavons genistein, formononetin and daidzein in clover genus plants by HPLC method.
Objective: to perform analysis of scientific literature and evaluate characteristics of clover genus (Trifolium L.) plants and their usage for medical purpose, and analysis methods of active components. Select the conditions of extraction considering influence of solvent, its polarity and time of extraction. Optimize HPLC method for raw material analysis of clover genus and justify its suitability for quantitative analysis of isoflavons. Perform analysis of isoflavons in different parts of various clover genus plants by optimized HPLC method. Evaluate quantity difference between isoflavons in various genus of clover. Evaluate quantity difference between isoflavons in different parts of plants. Compare quantities of isoflavons in different parts of T. pratense pants. Compare quantity difference between isoflavons in raw materials of cultivated and naturally grown T. pretense plants.
Results: performed scientific literature analysis justified characteristics and therapeutic effects of clover genus (Trifolium L.) plants, evaluated analysis methods of flavonoids and isoflavonoids. Also was evaluated influence of polarity of solvent and time of extraction to quantity of isoflavons. Quantitative HPLC analysis method for isoflavons in raw materials of clover... [to full text]
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Diehl, Michelle Schalemberg. "PASTAGENS DE CAPIM ELEFANTE E AZEVÉM CONSORCIADAS COM LEGUMINOSAS." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/4367.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The objective of this study was to conduct analysis of data from six experiments with forage systems with Elephant Grass (EG) + Italian Ryegrass (IR) + Spontaneous Growing Species (SGS); EG + IR + SGS + Forage Peanut; and EG + IR + SGS + White or Red Clover, conducted in the Laboratório de Bovinocultura de Leite da Universidade Federal de Santa Maria, with rotational grazing using dairy cattle. The experiments analyzed were conducted between the years 2005 to 2013 and grouped by the month they grazing cycles were performed. Holstein dairy cows were used for evaluation, with an average body weight and milk production of 543 kg and 19 kg/day, respectively. The total forage production values and the average stocking rate and crude protein levels were 13.8, 16.5 and 16.8 t/ha; 2.90; 2.91 and 2.92 AU/ha/day and 17.5, 18.6 and 18.2%, for the respective forage systems. The forage systems consisting by forage legumes presented the best results in relation to pasture productivity and nutritive value of forage. The mixed with forage peanut controlled the spontaneous growing species and participated in the herbage mass throughout the year. In mixed pasture with clovers the nitrogen contribution to the system resulted in better conditions for the development of grasses forage (Italian ryegrass or elephant grass).<br>O objetivo desse estudo foi comparar sistemas forrageiros sem leguminosa e em consórcio, por meio de uma análise conjunta de dados provenientes de seis experimentos conduzidos no Laboratório de Bovinocultura de Leite da Universidade Federal de Santa Maria. Os sistemas forrageiros constituíram-se por capim elefante (CE) + azevém (AZ) + espécies de crescimento espontâneo (ECE), sem leguminosa; CE + AZ + ECE + amendoim forrageiro; e CE + AZ + ECE + trevo branco ou vermelho. Os experimentos foram realizados entre os anos de 2005 a 2013 e agrupados pelo mês em que foram efetuados os ciclos de pastejo. Para avaliação foram usadas vacas em lactação da raça Holandesa, com peso corporal e produção de leite média de 543 kg e 19 kg/dia, respectivamente. Os valores de produção de forragem e as médias de taxa de lotação e dos teores de proteína bruta foram de 13,8; 16,5 e 16,8 t/ha; 2,90; 2,91 e 2,92 UA/ha/dia e 17,5; 18,6 e 18,2%, para os respectivos sistemas forrageiros. Os sistemas forrageiros constituídos por leguminosas apresentaram os melhores resultados em relação à produtividade do pasto e ao valor nutritivo da forragem. O consórcio com amendoim forrageiro controlou as espécies de crescimento espontâneo e participou da massa de forragem durante todo o ano. No consórcio com trevos a contribuição de nitrogênio ao sistema implicou em melhores condições para o desenvolvimento das gramíneas acompanhantes (azevém ou capim elefante).
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Kemball, W. D. "Source-sink interrelationships in white clover (Trifolium repens L.)." Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333705.
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Carlsson, Georg. "Input of nitrogen from N2 fixation to northern grasslands /." Umeå : Dept. of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200576.pdf.
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Nichols, Phillip Geoffrey Harwood. "Evolution in sown mixtures of subterranean clover (Trifolium subterraneum L.)." University of Western Australia. School of Plant Biology, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0008.
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[Truncated abstract] Evolution in two genetically diverse sown populations of subterranean clover (Trifolium subterraneum L.) was examined over 16 years at Mt Barker, a long growing season site, and at Nabawa, a short growing season site, in south-west Western Australia. One population consisted of a mixture of 40 strains sown in equal proportions, while the other was a bulk-hybrid population consisting of F2 seed from 253 crosses. Seed harvested annually and kept in cold storage was grown in an irrigated common garden at the University of Western Australia Field Station at Shenton Park, along with samples of the ancestral mixtures, to examine changes within these populations. Evolution in the strain mixture populations was measured by changes in strain frequency; strains were considered ecologically successful if their relative contribution was maintained or increased from that at sowing. Mixtures containing an additional 12 cultivars were also sown at each site to examine short-term population changes. The relative importance of 38 attributes measured in single-strain swards and spaced plants at Nabawa and Mt Barker was then related to strain success in mixtures at each site. Evolution in the bulk hybrid populations was measured in spaced plants at Shenton Park by changes in mean values and variability of 26 attributes. The ancestral populations evolved into markedly different populations at each site. Most evolution occurred within three years of sowing, due to elimination of poorly adapted genotypes. Within sites, the direction of selection was similar for both mixtures. In the strain mixture populations, different strains became dominant at each site. Divergent strains, those not identical to the sown strains, were significant components of the populations, particularly at Mt Barker, but their frequency did not increase. In the bulk hybrid populations, changes occurred in the means of 20 characters and variability declined in 11 characters at one or both sites. Appropriate flowering time was fundamental for success in both environments. At Nabawa, early flowering was crucial, while successful genotypes at Mt Barker were midseason and late flowering. Flowering time in both environments was a compromise between sufficient earliness for adequate seed production prior to the onset of summer drought, and deferment for as long as possible to allow plants to develop maximum size to compete for light in spring. The balance between these two competing forces differed in response to length of the growing season at each site
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Sivesind, Evan. "Factors affecting isoflavone concentration in red clover (Trifolium pratense L.)." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84075.
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Red clover (Trifolium pratense L.) contains isoflavones, which are of interest because of their benefits for human health as well as their adverse effects on the fertility of farm animals. Isoflavone concentration in 10 cultivars ranged from 8923 to 12753 mug g-1 DM averaged across sites, harvests, and years. One cultivar, 'Start', distinguished itself with particularly low isoflavone levels. Concentrations varied according to plant part with leaves having the highest levels followed by stems and inflorescences, when averaged across maturity levels and cultivars (11970, 4896 and 3297 mug g-1 DM, respectively). Greatest content was found in leaves and stems during vegetative stages. Fresh herbage contained higher isoflavone content than either silage or hay (14464, 12200 and 11604 mug g-1 DM, respectively). Foliar application of yeast extract, chitosan, and acetic acid elicitors overall showed modest (12-15%) increases in isoflavone concentration over untreated control plants. Differences were not observed between elicitor concentrations used.
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Довгопола, Катерина Анатоліївна, та Тетяна Семенівна Брюзгіна. "ВПЛИВ УМОВ ПРОРОСТАННЯ НА ЖИРНОКИСЛОТНИЙ СКЛАД ЛІПІДІВ TRIFOLIUM PRATENSE L". Thesis, Мегапринт, 2013. http://er.nau.edu.ua/handle/NAU/10106.
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Stöber, Sara. "Einfluss von erhöhtem atmosphärischen CO 2 auf die N 2-fixierende Symbiose von Trifolium repens L. und Rhizobium leguminosarum biovar trifolii." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-2071.
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Denton, Matt. "Influence of naturalised Rhizobium leguminosarum bv. trifolii populations on the nodulation of alternative clovers (Trifolium spp.) in alkaline soils / Matt Denton." Adelaide, Sth. Aust, 2000. http://hdl.handle.net/2440/22423.
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Bibliography: leaves 186-209.<br>xiii, 218 leaves : ill. (some col.), 1 col. map ; 30 cm.<br>Title page, contents and abstract only. The complete thesis in print form is available from the University Library.<br>Thesis (Ph.D.)--Adelaide University, Dept. of Agronomy and Farming Systems, 2000
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Zhou, He. "Biologie comparée d'écotypes de Trifolium pratense L. : diversité des fonctions de croissance et de reproduction." Dijon, 1992. http://www.theses.fr/1992DIJOS059.
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Les recherches ont été conduites sur la diversité de quelques écotypes de trèfle violet (Trifolium pratense L. ) Provenant de milieux différents au point de vue géographique et écologique. Sept écotypes ont été particulièrement étudiés pour les différentes phases de leur cycle biologique: établissement, croissance et reproduction. La marque foliaire, le port de la plante, la forme de la feuille et la longueur du tube corollin ont été également étudiés comme caractéristiques écotypes. Les écotypes provenant de la région méditerranéenne possèdent les plus grosses graines. L'effet de la taille de la graine a été confirmé à l'établissement de la plantule. Le changement de la constante phyllochronique entre le semis et la dixième feuille apparue pour tous les écotypes confondus est à mettre en relation avec le rythme de développement et n'est pas une caractéristique écotypique. La temperature devient un des facteurs limitant de la mise à fleurs en condition de photopériode favorable. Les réactions pour la température élevée entre les écotypes ne sont pas identiques. Les allocations reproductives reflètent des différences de stratégie d'adaptation au milieu. Une relation existe entre le taux de nouaison et la longueur du tube corollin. Des applications de la connaissance des particularités écotypiques sont envisagées
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Denton, Matt. "The influence of naturalised Rhizobium leguminosarum bv. trifolii populations on the nodulation of alternative clovers (Trifolium spp.) in alkaline soils / Matt Denton." Thesis, Adelaide, Sth. Aust, 2000. http://hdl.handle.net/2440/22423.
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Sharif, Abid Latif. "A molecular study of the Li locus of Trifolium repens L." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265140.
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Abdul, Jalil A. I. "The growth and colonisation of rhizobia on mycorrhizal Trifolium repens (L.)." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370869.
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Сахацька, І. М. "Конюшина лучна (Trifolium pratense) як перспективне джерело для отримання лікарських засобів". Thesis, БДМУ, 2020. http://dspace.bsmu.edu.ua:8080/xmlui/handle/123456789/18263.
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Friedericks, James Bahadur. "Evaluation of African trifolium species for growth and biological nitrogen fixation." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54529.
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Throughout the African highlands forage legumes are relied on to add soil N, support increasing livestock populations, and reduce soil erosion. This research addresses a constraint designated by the International Livestock Center for Africa (ILCA) to identify African clover (Trifolium) germplasm and Rhizobium trifolii strain combinations with high productivity potential for the African highlands. A Vertisol and an Eutric Nitosol (Paleudalf), and seed from Trifolium decorum, T. quartinianum, T. rueppellianum, T. steudneri, and T. tembense were obtained from ILCA in Addis Ababa, Ethiopia. A commercial collection and R. trifolii strains isolated from the Ethiopian soils were evaluated for symbiotic effectiveness with these clovers. Effective combinations were evaluated for growth and biological nitrogen fixation (BNF) in a greenhouse on both soils with limited, adequate, and excessive soil moisture. Rhizobia were also evaluated for survival in desiccated soil (12.5 and 17.5 g H₂O g⁻¹ soil) and for competitive nodule forming ability. Effective strains were found among soil isolates but not in the commercial collection. Highest dry matter yields and total BNF accumulation were obtained from T. tembense on all soil and moisture treatments followed by T. decorum and T. quartinianum.
Trifolium rueppellianum and T. steudneri had low yields and BNF capacities. Plants receiving adequate and excessive moisture had higher yields than moisture stressed plants. The highest levels of cumulative BNF were obtained on the nitosol soil with either adequate or limited moisture. The moisture limited vertisol supported the lowest BNF levels. Rhizobial strains survived desiccation only in the vertisol at 17.5 g H₂O g⁻¹ soil. All strains could compete with background rhizobia populations to nodulate host plants. Nodule occupancy rates of 20 to 30% were required for high yields. Trifolium tembense, T. decorum, and T. quartinianum are adapted to soils with adequate or excessive moisture, T. rueppellianum and T. steudneri are suited to moisture limited conditions or short growing seasons. Effective rhizobia inoculants and selected clovers have the potential for increasing forage productivity in highland areas.<br>Ph. D.
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Parco, Socorro Z. "The influence of motility of rhizobium leguminosarum biovar trifolii TA1 on the colonization and nodulation of roots of trifolium subterraneum cv. Mt. Barker." Thesis, Parco, Socorro Z. (1993) The influence of motility of rhizobium leguminosarum biovar trifolii TA1 on the colonization and nodulation of roots of trifolium subterraneum cv. Mt. Barker. Masters by Research thesis, Murdoch University, 1993. https://researchrepository.murdoch.edu.au/id/eprint/51939/.
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The significance of motility for root colonisation and nodulation was investigated by comparing the behaviour of well-characterised motile (MNF 1000) and non-motile (MNF 1005) strains of Rhizobium leguminosarum bv. trifolii. A very small volume (5 pi) was used to inoculate clover (Trifolium subtcrrancum cv. Mt. Barker) roots to avoid mass flow of organisms. The nodulation pattern was used as an index of the colonisation of the roots; it was assessed by a grid-sectioning technique which divided the soil column into 1 cm cubes, or by gamma-ray computer assisted tomography (CAT) scanning. Direct rhizosphere counts were used as an alternative way of determining root colonisation.
From equal inocula, the motile strain produced more nodules than the nonmotile. Grid-sectioning showed that the motile strain produced nodules at distances further from the inoculation point than the non-motile mutant. However, the technique suffered from the distortion of root aiH nodule distribution caused by the introduction of the sectioning plate.
Attempts were made to use CAT scanning as a non-destructive, nondistorting technique to generate a three-dimensional picture of nodule distribution in the soil columns. Although some 70% of the known nodules corresponded to areas of low density in the scans, the technique currently lacks sufficient resolution.
When the root nodule bacteria were located on the roots by direct counting, the motile strain was found along the whole of the tap root, while the non-motile mutant was essentially confined to a small zone at the inoculation point, rhizosphere counts indicated a much greater spread of the motile strain than did The measurement of the nodule distribution.
In steam-treated soil, both nodulation and rhizosphere counts indicate that the motile strain colonised the clover root system much more extensively than did the non-motile strain.
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Öhberg, Helena. "Studies of the persistence of red clover cultivars in Sweden : with particular reference to Sclerotinia trifoliorum /." Umeå : Dept. of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200808.pdf.
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McLean, Nancy L. "A genetic study of somatic embryogenesis in red clover (Trifolium pratense L.)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24779.pdf.
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Tesfaye, Mesfin. "Genetic diversity and symbiotic effectiveness of Rhizobium isolated from perennial Trifolium species." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25054.pdf.
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Madan, Nanette Joanna. "The effect of nodal rooting on resource integration in Trifolium repens L." Thesis, Bangor University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265233.
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Gooding, Roderick F. "Cutting and grazing systems for grass/white clover Trifolium repens L. associations." Thesis, University of Glasgow, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264055.
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George, S. "The survival and growth of white clover (Trifolium repens) in upland soils." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370157.
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Hargreaves, Serene. "Genetic diversity studies of Trifolium species from the extremes of the UK." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1621/.
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Crop wild relatives have been identified as ecologically and economically important plant genetic resources but are often a neglected resource. The recognition of the need for their specific conservation and their value for future use has been strengthened by the Convention on Biological Diversity and the International Treaty on Plant Genetic Resources for Food and Agriculture, both of which have been ratified by the UK. This thesis provides a detailed view of the ecological, geographic and genetic background to three crop wild relative species, Trifolium dubium, T. pratense and T. repens, of which the latter two are amongst some of the most economically important legume species in the UK. Assessments of ecogeography, amplified fragment polymorphism and single nucleotide polymorphism markers were employed to investigate the distribution of variation in these species across the UK, including outlying island sites. Based on this information it was possible to look for isolation by distance in populations in UK; identify areas containing unique variation; assess the conservation importance of island sites surrounding the UK and speculate on the causes of the observed patterns of diversity. Conservation recommendations were based on the cumulative data from this research to identify how the recommendations change with an increased focus on genetic diversity. These results provide insights into the use of different types of background information when setting conservation plans in widespread species, contributing to the development of conservation strategies for widespread species in general.
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Hattenbach, Meryl Jennifer. "Edaphic relations of an endangered plant, Trifolium stoloniferum Muhl. ex A. Eaton." Connect to resource, 1996. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1261052966.
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Elizabete, Lima Lins Cláudia. "Efeito do cobre sobre fungos micorrízicos e trevo vermelho (Trifolium pratense L.)." Universidade Federal de Pernambuco, 2006. https://repositorio.ufpe.br/handle/123456789/620.
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Made available in DSpace on 2014-06-12T15:04:09Z (GMT). No. of bitstreams: 2
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Previous issue date: 2006<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>RESUMO GERAL Foram avaliados os efeitos do cobre sobre fungos micorrízicos
arbusculares (FMA) e ectomicorrízicos (FEM) e sobre a simbiose entre FMA e plantas de
trevo. Diversidade de espécies, densidade de esporos, número mais provável (NMP) de
propágulos e produção de glomalina por FMA foram estimados em área de mineração de
cobre (rejeito, margem e reflorestada com eucaliptos) em Camaquã, RS. A simbiose trevo
vermelho (Trifolium pratense L.) com o FMA Glomus etunicatum Becker & Gerd. foi
observada em areia recebendo solução nutritiva. Os FEM Pisolithus microcarpus UFSC
Pt116, Chondrogaster angustisporus UFSC Ch163 e Suillus sp. UFSC Su168 foram
cultivados em meio acrescido de Cu (31 a 7869 μM) e dois níveis de P (0,1 e 1,9 mM). A
atividade de fosfatases produzidas por Suillus sp. em meio com adição de Cu e de P foi
igualmente estimada. Este fungo foi mais tolerante que os demais FEM em meio com
concentração 123 μM Cu. A adição de P diminuiu significativamente a toxicidade do Cu
sobre os FEM. O crescimento micelial, em meio líquido, foi fortemente inibido pelo fósforo
(1,9 mM) e pelo Cu (123 μM). No entanto, houve aumento de 50% na atividade de fosfatases
produzidas por Suillus sp. Para este fungo, as concentrações de Cu inibitórias de 50% do
crescimento (CI50) foram 40 e 160 μM Cu, respectivamente em meios sólido e líquido. Doze
táxons de FMA foram identificados nas áreas estudadas. Glomus foi o gênero mais comum e
Paraglomus brasilianum (Spain & Miranda) Morton & Redecker a única espécie encontrada
nas três áreas. Menor diversidade de FMA ocorreu na área de interface entre a bacia de rejeito
e a reflorestada. Maior número de esporos, NMP de propágulos e produção de glomalina
foram registrados na área reflorestada. Efeito deletério do Cu foi observado nas plantas de
trevo mantidas em substrato com 1967 μM de Cu. A micorrização, traduzida pela
colonização radicular, foi inibida em substrato com 123 μM Cu; porém, neste mesmo nível,
a adição de fosfato diminuiu a toxicidade do metal. No tratamento inoculado com G.
etunicatum e com 1,9 mM P a toxicidade do Cu sobre o crescimento e acúmulo de nutrientes
(P, K, Cu e Fe) nas plantas de trevo também diminuiu. Os resultados indicam que a
inoculação com FMA e a adição de fosfato podem aumentar a tolerância do hospedeiro a
níveis elevados de Cu no substrato. Nesse contexto, a aplicação conjunta de fungos
micorrízicos e P podem constituir uma prática favorável no reflorestamento de áreas de
mineração
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Giorno, Cecilia Del. "Efeitos do Trifolium pratense nos sintomas da menopausa e na satisfação sexual em mulheres climatéricas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5139/tde-22022010-170555/.
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Objetivo: avaliar os efeitos do tratamento com o Trifolium pratense nos sintomas menopausais em mulheres climatéricas utilizando o Índice Menopausal de Kupperman (IMK) e pelo Inventário de Satisfação Sexual Golombok e Rust versão feminina (GRISS) l. Metodologia: Este estudo foi prospectivo, randomizado, duplo cego e controlado com placebo, e realizado no setor de Ginecologia Endócrina e Climatério da Disciplina de Ginecologia do Departamento de Obstetrícia e Ginecologia do Hospital das Clínicas, da Faculdade de Medicina da Universidade de São Paulo. Foram selecionadas 100 mulheres na faixa etária de 45 a 65 anos com sintomas menopausais, com amenorréia superior há 1 ano e sem tratamento nos últimos 6 meses. Após a seleção, as mulheres foram divididas em dois grupos: Grupo I (n = 50) receberam Trifolium pratense na dose de 40 mg, 1 capsula/dia, por via oral; Grupo II (n = 50) receberam placebo (controle), contendo lactose, 1 cápsula/dia por via oral. A duração do tratamento foi de 12 meses e as mulheres foram avaliadas antes do tratamento com quatro, oito e 12 meses de tratamento, por exames clínico e laboratorial. Aplicaram-se o teste de t Student e o ANOVA para avaliar as diferenças entre os grupos. Resultados: Houve melhora significante dos sintomas após quatro meses de tratamento no IMK, principalmente, as ondas de calores, em relação aos dados antes do tratamento nos dois grupos. Não observamos melhora na avaliação da sexualidade (GRISS). Conclusão: Nossos dados sugerem que o efeito da ministração de 40mg ao dia de Trifolium pratense pode não ser superior ao do placebo, na redução dos sintomas da pós-menopausa durante um ano de estudo<br>Objective: to evaluate the effects of Trifolium pratense treatment on the climacteric symptoms and sexualiy in postmenopausal women through Kuppermann Menopausal Index (KMI) and the Golombok Rust Inventory of Sexual Satisfaction (GRISS), respectively. Methods: This study was prospective, randomized, double-blind and placebo-controlled study. Hundred women were selected, aged between 45 and 65 years with climacteric symptoms, with menstruation absence (amenorrhea) that was more then one year and without any treatment for last six months. After selection, women were divided into two groups: GI (n = 50) received 40 mg Trifolium pratense (one capsule per day); GII (n = 50) received placebo (control, one capsule of lactose per day). The length of treatment was 12 months and women were evaluated before and after four, eight and twelve months of treatment through clinical and laboratorial exams. The t Student test and ANOVA were applied for analyzing the differences between groups. Results: There was significant ameliorate in the symptoms after four months of treatment through the KMI, mainly in hot flashes, compared to baseline data of both groups. The sexuality evaluation did not found any difference before and after treatment in both groups. Conclusion: Our data suggested that the 40 mg Trifolium pratense effect may be not superior than placebo in relation to decrease the postmenopausal symptoms during one year of study
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Dias, Paula Hollweg. "Obtenção de fração enriquecida em isoflavonas de Trifolium pratense L e avaliação da permeação cutânea de formononetina e biochanina A incorporadas em hidrogel de HPMC contendo ciclodextrinas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/175146.
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A formononetina e a biochanina A são as isoflavonas majoritárias nas partes aéreas de Trifolium pratense L. (trevo-vermelho) relacionadas com as principais atividades farmacológicas da planta. São chamadas de fitoestrógenos, pois possuem estrutura similar ao do 17-β-estradiol, e são capazes de se ligar aos receptores estrogênicos (ERβ e ERα). As isoflavonas agliconas são moléculas de baixa hidrossolubilidade, o que pode limitar sua aplicação em produtos para pele e a expressão de sua atividade biológica. O presente trabalho tem como objetivo obter uma fração enriquecida em isoflavonas de T. pratense e avaliar a permeação cutânea das agliconas formononetina e biochanina A individualmente e associadas. Adicionalmente, o efeito de promoção da permeação cutânea em pele de orelha suina também foi objeto do estudo. A fração foi preparada por maceração e após precipitação das isoflavonas agliconas por evaporação do etanol, o precipitado foi separado por filtração e purificado por cromatografia em coluna de poliamida. O produto foi seco e apresentou concentração de isoflavonas de 2,8 mg/g de formononetina e 2,7 mg/g de biochanina A. No entanto, essa concentração ainda não foi suficiente para posterior incorporação em uma formulação visando testes de permeação cutanea. Neste contexto, os estudos de permeação em pele de orelha de suíno (Franz cells) foram realizados com as isoflavonas majoritárias de referência incorporadas à hidrogéis de hidroxipropilmetilcellulose (HPMC). Para avaliar o teor de isoflavonas nas formulações e nas diferentes camadas da pele foi desenvolvido método bioanalítico utilizando cromatografia líquida de alta eficiência, o qual mostrou-se linear, específico, exato, preciso e robusto. Os hidrogéis foram desenvolvidos utilizando como polímero HPMC (3,5%, m/v) e as isoflavonas (0,1%) foram incorporadas à essa base, individualmente ou associadas, em presença ou ausência de hidroxipropil-β-ciclodextrina (HPβCD) ou metil-β-ciclodextrina (MβCD). Os resultados obtidos na avaliação da permeação cutânea revelaram que as isoflavonas permearam mais quando incorporadas individualmente na base especialmente a formononetina. A biochanina A apresentou maior capacidade de permeação do que a formononetina, alcançando concentrações na epiderme de 0,5 ug/cm2 e na derme de 1,5 μg/cm2, representando cerca de 2,7 vezes mais comparando com a concentração de formononetina (respectivamente, 0,2 μg/cm2 e 0,4 μg/cm2). uso de ciclodextrinas aumentou significativamente a permeação da formononetina, tanto na epiderme quanto na derme. Para a biochanina A, apenas a retenção na epiderme foi aumentada com a presença de ciclodextrinas. A HPβCD foi a ciclodextrina que apresentou os melhores resultados de promoção da permeação da formononetina na derme e epiderme, proporcionando um aumento de 113%. Para a biochanina A, as duas ciclodextrinas aumentaram a sua concentração na epiderme na mesma proporção (37%). Quando as duas isoflavonas foram incorporadas em misturas 1:1 no hidrogel, a formononetina apresentou menor retenção, tanto na epiderme (0,1 μg/cm2) quanto na derme (0,4 μg/cm2). Contrariamente, a biochanina A apresentou retenção semelhante àquela apresentada quando foi incorporada isoladamente no hidrogel, caracterizando-se como uma molécula mais permeável e não sofrendo interferência da formononetina na sua permeação e retenção. Não foi observado efeito significativo da presença das ciclodextrinas na promoção da permeação cutânea das isoflavonas nas misturas, exceto para a formononetina, na epiderme. O conjunto dos resultados demonstrou que a formononetina e biochanina A são capazes de permear a pele sendo majoritariamente retidas na epiderme e na derme, revelando o seu potencial uso em preparações cosméticas destinadas à prevenção do envelhecimento cutâneo. As ciclodextrinas apresentaram acentuado efeito promotor da permeação cutânea apenas para a formononetina, que apresenta menor permeabilidade.<br>The main isoflavones present Trifolium pratense L. (red clover) aereal parts are the isoflavones formononetin and biochanin A, related to its pharmacological activities. These compounds are known as phytoestrogens due to its similarity to the structure of 17-β-estradiol, being able to bind to the estrogen receptor (ERβ and ERα). Aglicones of isoflavones display low water solubility limiting its incorporation in products for the skin and expression of its biological activity. The present work aims to develop a isoflavones-enriched fraction of T. pratense and to evaluate the skin permeation of the aglicones formononetin and biochanin A individually, and in association. Moreover the promoter effect of cyclodextrins on their skin permeation will also be evaluated. The enriched-fraction was prepared by maceration in ethanol 40% (v/v). The ethanol was evaporated and the dispersion was filtered. The supernatant was purified using a column chromatography packet with polyamide. The final product was dried and presented a concentration of 2.8 mg/g of formononetin and 2.7 mg/g of biochanin A. However, these amounts of isoflavones were not enough for subsequent incorporation into a formulation to proceed the cutaneous permeation tests. In this context, the permeation studies were performed using the chemical reference formononetin and biochanin A, incorporated into the hydroxypropyl methylcellulose (HPMC) hydrogels for the permeation studies on porcine ear skin (Franz cells). To evaluate the isoflavone concentration in the formulations and in the different skin layers, a bioanalytical method was validated using high performance liquid chromatography (HPLC), which showed linearity, specificity, accuracy, precision and robusteness. Hydrogels were developed using HPMC (Methocel® K4M) polymer (3.5%, m/v) and the isoflavones were incorporated into this base individually or in combination, in the presence or absence of hydroxypropyl-β-cyclodextrin (HPβCD) or methyl-β-cyclodextrin (MβCD). The results obtained in the cutaneous permeation tests showed higher permeation values when the isoflavones were individually incorporated into the formulations especially for formononetin. Biochanin A showed higher permeation capacity when compared to formononetin, reaching 0.5 μg/cm2 in the epidermis and 1.5 μg/cm2 in the dermis, representing about 2.7 times the concentration of formononetin (0.2 μg/cm2 and 0.4 μg/cm2). The use of cyclodextrins increased significantly the permeation values of formononetin, both in the epidermis and in the dermis. For biochanin A only the retention in the epidermis was increased. HPβCD was the cyclodextrin that showed the best results for formononetin as permeation promoter, providing an increasing in the epidermis and dermis of 113%. Both cyclodextrins improved the biochanin A permeation in the same proportion in the epidermis (37%). When the isoflavones were incorporated into hydrogels together (1:1 ratio), formononetin showed less retention in both skin layers (0.1 μg/cm2 in the epidermis and 0.4 μg/cm2 in the dermis) and biochanin A remained with similar performance when added alone. In the presence of cyclodextrins, no significant effect was observed in the promotion of skin permeation of isoflavones in mixtures, except for formononetin, in the epidermis. Taken together, the results indicated that formononetin and biochanin A present skin permeation being mostly retained in the epidermis and dermis, revealing its potential use in cosmetic products preparations for preventing skin aging. Cyclodextrins presented a marked skin permeation promoting effect only on formononetin, which molecule presents lower permeability.
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Baur-Höch, Brigitte. "Einfluss von Restblattfläche und Reservekohlenhydraten auf den Wiederaustrieb von Weissklee (Trifolium repens L.) /." [S.l.] : [s.n.], 1988. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8580.
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Gravuer, Kelly. "Determinants of the introduction, naturalisation, and spread of Trifolium species in New Zealand." Master's thesis, Lincoln University. Bio-Protection and Ecology Division, 2004. http://theses.lincoln.ac.nz/public/adt-NZLIU20071015.060329/.
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Two conceptual approaches which offer promise for improved understanding of biological invasions are conceptualizing the invasion process as a series of distinct stages and explicitly incorporating human actions into analyses. This study explores the utility of these approaches for understanding the invasion of Trifolium (true clover) species in New Zealand. From the published literature, I collected a range of Trifolium species attributes, including aspects of global transport and use by humans, opportunistic association with humans in New Zealand, native range attributes, habitat characteristics, and biological traits. I also searched historical records to estimate the extent to which each species had been planted in New Zealand, a search facilitated by the enormous importance of Trifolium in New Zealands pastoral agriculture system. Regression analysis and structural equation modelling were then used to relate these variables to success at each invasion stage. Fifty-four of the 228 species in the genus Trifolium were intentionally introduced to New Zealand. Species introduced for commercial agriculture were characterised by a large number of economic uses and presence in Britain, while species introduced for horticulture or experimental agriculture were characterised by a large native range area. Nine of these 54 intentionally introduced species subsequently naturalised in New Zealand. The species that successfully naturalised were those that had been planted extensively by humans and that were well-matched to the New Zealand climate. A further 16 species (from the pool of 174 species that were never intentionally introduced) arrived and naturalised in New Zealand without any recorded intentional aid of humans. Several attributes appeared to assist species in unintentional introduction-naturalisation, including a good match to the New Zealand climate, a large native range area, presence in human-influenced habitats, a widespread distribution in Britain, and self-pollination capability. The 25 total naturalised species varied greatly in their current distributions and in the rates at which they had spread to achieve those distributions. Species that had spread quickly and are currently more widespread had been frequent contaminants in the pasture seed supply and have a long flowering period in New Zealand. Other biological traits and native range attributes played supporting roles in the spread process. Attributes facilitating success clearly varied among invasion stages. Humans played a dominant role at all stages of this invasion, although biological traits had increasing importance as a species moved through the invasion sequence. My findings suggest that incorporation of human actions and the stage-based framework provide valuable insight into the invasion process. I discuss potential avenues by which these approaches might be integrated into predictive invasion models.
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Ates, Serkan. "Grazing management of subterranean clover (Trifolium subterraneum L.) in South Island (New Zealand)." Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1338.
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This study consisted of two sheep grazed dryland pasture experiments. Experiment l compared sheep production from 3-year-old cocksfoot based pastures grown in combination with white, Caucasian, subterranean or balansa clover with a ryegrass-white clover pasture and a pure lucerne forage. Sheep liveweight gain per head from each pasture treatment and the pure lucerne stand was recorded in the 2006/07 and 2007/08 seasons. The cocksfoot-subterranean clover pasture provided equal (381 kg LW/ha in 2006) or higher (476 kg LW/ha in 2007) animal production in spring and gave the highest total animal production (646 kg LW/ha) averaged across years of the five grass based pastures. However, total annual liveweight production from lucerne was higher than any grass based pasture mainly due to superior animal production during summer when lucerne provided 42-85% higher animal production than any of the grass based pastures. In Experiment 2, the effect of stocking rate (8.3 (low) and 13.9 (high) ewes + twin lambs/ha) and time of closing in spring on lamb liveweight gain, pasture production and subterranean clover seedling populations was monitored over 2 years for a dryland cocksfoot-subterranean clover and ryegrass-subterranean clover pasture in Canterbury. In both years, twin lambs grew faster (g/head/d) in spring at low (327; 385) than high (253; 285) stocking rate but total liveweight gain/ha (kg/ha/d) was greater at high (7.26; 7.91) than low (5.43; 6.38) stocking rate. Ewes also gained 0.5 and 1.5 kg/head at the low stocking rate in 2006 and 2007 respectively but lost 0.2 kg/head in 2006 and gained 0.3 kg/head at high stocking rate in 2007. Mean subterranean clover seedling populations (per m²) measured in autumn after grazing treatments in the first spring were similar at both low (2850) and high (2500) stocking rate but declined with later closing dates in spring (3850, 2950, 2100 and 1700 at 2, 4, 6, 8 weeks after first visible flower). Seedling populations measured in autumn after grazing treatments in the second spring were also unaffected by stocking rate (low 1290, high 1190) but declined with later closing dates in spring (1470, 1320 and 940 at 3, 5 and 8 weeks after first flowering, respectively). The effect of stocking rate and closing dates in spring on pasture and clover production in the following autumn was similar to the effects on seedling numbers in both years. However, clover production in the following spring was unaffected by stocking rate or closing date in the previous year at the relatively high seedling populations generated by the treatments. This was presumably due to runner growth compensating for lower plant populations in pastures that were closed later in spring. Subterranean clover runner growth in spring may not compensate in a similar manner if seedling numbers in autumn fall below 500/m². Mean annual dry matter production from cocksfoot and ryegrass pastures grown with and without annual clovers pasture production ranged from 6.4 to 12.4 t DM/ha/y but stocking rate (8.3 vs. 13.9 ewes/ha) during spring did not affect annual pasture production. Pastures overdrilled with annual clovers yielded 23-45% more dry matter production than pastures grown without annual clovers. The study confirms the important role of subterranean clover in improving pasture production and liveweight gains of sheep in dryland cocksfoot and ryegrass pastures. Lowering stocking rate from 13.9 to 8.3 ewes/ha was a less effective method of increasing seed production of subterranean clover in dryland pastures although it did lead to increased liveweight gain per head.
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De, Koning Carolyn Theresa. "The ecology and productivity of new cultivars of subterranean clover(Trifolium subterraneum L.)." Title page, contents and abstract only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phd328.pdf.
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Kongkiatngam, Prasert. "Short-term biomass production of red clover (Trifolium pratense L.) and its inheritance." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61152.
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The objective of this study was to evaluate the short-term (one-year) biomass production in red clover and to obtain an estimate of the heritability of this characteristic. Progenies from parents with high biomass had higher biomass than those from parents with low biomass or having one parent in each category. The narrow-sense heritability estimated from mid-parent offspring regression was 0.23, from parent-offspring correlation was 0.22, and realized heritability was 0.15, indicating that progeny testing would be required for successful selection of populations with greater biomass production. Plants selected for high biomass production tended to have higher shoot:root ratios and flower more profusely than the parental checks and the low biomass plants. This indicates that by selecting for high biomass, red clover will be selected for more annual growth habit at the same time.
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Evans, Thomas George. "Isolation of Cytokinin Biosynthesis and Metabolic Genes from White Clover (Trifolium repens L)." Thesis, University of Canterbury. School of Biological Science, 2009. http://hdl.handle.net/10092/4821.
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The factors influencing senescence in white clover (Trifolium repens L.) are of considerable importance to the pastoral sector of New Zealand’s economy. The plant hormones, ethylene and the cytokinins, have been implicated as having opposing influences on senescence. This project focused on the cytokinins. The rate limiting step in cytokinin biosynthesis is catalysed by isopentenyl transferase (IPT) and the primary enzyme in the degradation of cytokinins is cytokinin oxidase/dehydrogenase (CKX). Both IPT and CKX genes are present as multi-gene families. A reduction in the level of active cytokinins either via a decrease in IPT expression, or an increase in CKX expression, or both, would implicate the cytokinins in developmental leaf senescence in white clover.
White clover grows in a sequential pattern with leaves at all stages of development making it a good model for studying leaf development and senescence. A decrease in leaf chlorophyll is used as a marker for the onset of senescence. A micro-scale chlorophyll analysis was developed using the NanoDrop™ thus allowing tissue from the same leaflet to be used for gene expression and chlorophyll measurements. The pattern of chlorophyll changes was similar to that shown by Hunter et al.(1999) and Yoo et al.(2003) in white clover stolons used for ethylene research. Reverse transcriptase PCR (RT-PCR) and BLAST analysis was used to identify five putative IPT genes and seven putative CKX genes from white clover. RT-PCR demonstrated the expression of seven of these genes (TrIPT1. TrIPT13, TrIPT15 TrCKX1, TrCKX2, TrCKX6). Analysis with quantitative real-time PCR showed expression of TrCKX2 increased markedly during leaf expansion and was consistently high during senescence, suggesting a potential role for CKX in facilitating the progression of senescence.
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Bortolini, Fernanda. "Caracterização morfológica e molecular da coleção básica de trevo-branco (Trifolium repens L.)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2004. http://hdl.handle.net/10183/3873.
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O objetivo deste trabalhofoi avaliarcaracterísticas moleculares e morfológicasde 79 acessos pertencentes à coleção básica de trevo-branco obtida do Departamento de Agricultura dos Estados Unidos(USDA), a fim de caracterizar a variabilidade genética existente.
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Rogers, Lauren Marie. "A taxonomic and biogeographic analysis of the Trifolium gracilentum species complex." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1565010559912396.
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Tressel, Lydia Grace. "A Morphological and Molecular Taxonomic Review of the Trifolium Depauperatum (Fabaceae) Species Complex." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami159527684395254.
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