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Putative pathogenesis-related genes within Solanum nigrum L. var. americanum genome: isolation of two genes coding for PR5-like proteins, phylogenetic and sequence analysis

Campos, Magnólia A.; Ribeiro, Simone G.; Grossi de Sá, Maria Fátima; Rigden, Daniel John; Monte, Damares de Castro
Fonte: Universidade Católica de Brasília Publicador: Universidade Católica de Brasília
Tipo: Artigo de Revista Científica Formato: Texto
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Pathogenesis-related (PR) proteins are involved in plant responses to biotic and abiotic stress and are grouped into 14 families (PR-1–PR-14). Two PR5-like genes were isolated from black nightshade (Solanum nigrum L. var. americanum) genome, a solanaceous weed. A complete open reading frame consisting of 744 bp, coding for a precursor of a neutral PR5-like protein, and a DNA fragment of 621 bp long, coding for another basic PR5-like protein, were obtained by using PCR amplification. Based on sequence comparisons with tobacco osmotin and osmotin-like proteins (OLPs), members of the antifungal PR-5 family, these proteins were named SnOLP (neutral) and SnOSML (basic). The two predicted mature proteins are 207 amino acids in length and contain the 16 cysteine residues involved in the eight disulfide bonds common to most PR-5 proteins. Southern blot analysis revealed that osmotin-like proteins are encoded by at least eight members of a multigene family in S. nigrum. This is the first report of the isolation of PR5-like genes from the S. nigrum genome. Computer modeling of the new sequences produces structures that, according to current hypotheses, are indicative of antifungal activity. Phylogenetic analysis of solanaceous PR-5 proteins was also carried out revealing three major groups with different characteristics.

Conditioned food aversion to Ipomoea carnea var. fistulosa induced by Baccharis coridifolia in goats

ADRIEN DELGADO, Mar?a de Lourdes; CORREA, Gabriela Riet; OLIVEIRA J?NIOR, Carlos Alberto de; PFISTER, James A.; COOK, Daniel; SOUZA, Elda Ely Gomes de; RIET-CORREA, Franklin; SCHILD, Ana Lucia
Fonte: Universidade Federal do Pará Publicador: Universidade Federal do Pará
Tipo: Artigo de Revista Científica
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Baccharis coridifolia ? uma planta t?xica que possui forte poder aversivo em ruminantes. Os objetivos deste trabalho foram induzir avers?o condicionada a Ipomoea carnea avar. fistulos em caprinos utilizando B. coridifolia como agente aversivo e comparar a efici?ncia desta avers?o com a avers?o induzida por cloreto de l?tio (LiCl). Treze cabras foram divididas em dois grupos: o Grupo 1 com seis cabras foi avertido com 175mg/kg de peso corporal (pc) de LiCl e o Grupo 2, com sete cabras, foi avertido com 0,25g/kg de pc de B. coridifolia seco. Todas as cabras foram avertidas no dia 1 logo ap?s a ingest?o de I.carnea. A avers?o foi repetida nos dias 2, 3 e 7 nos caprinos que ingeriram qualquer quantidade de I. carnea, utilizando-se o mesmo procedimento do dia 1. Os caprinos de ambos os grupos foram desafiados nas baias nos dias 23 e 38 ap?s o ?ltimo dia da avers?o e desafiados na pastagem nos dias 11, 15, 18, 20, 22, 25, 27 e 29 ap?s o ?ltimo dia da avers?o. Posteriormente os caprinos foram desafiados a cada 15 dias na pastagem at? o 330? dia ap?s o ?ltimo dia da avers?o (7? dia). Duas cabras do Grupo 1 ingeriram I. carnea no primeiro dia do desafio na pastagem, quatro dias ap?s o ultimo dia da avers?o nas baias. Al?m disso, outra cabra do mesmo grupo reiniciou a ingest?o da planta no 18? dia e outras duas no 20? dia. Uma cabra do Grupo 1 que nunca havia ingerido a planta ap?s a avers?o morreu no 55? dia. Uma cabra do Grupo 2 come?ou a ingerir I. carnea no primeiro dia de desafio na pastagem e uma segunda reiniciou o consumo da planta no 182? dia. No final do experimento no 330? as cinco cabras avertidas com B. coridifolia permaneciam sem ingerir a planta. Estes resultados sugerem que B. coridifolia ou algum princ?pio ativo dessa planta pode ser utilizado para induzir avers?o condicionada a plantas t?xicas. A utiliza??o de B. coridifolia como agente aversivo ? aparentemente mais barato e mais f?cil de ser utilizado do que o LiCl...

A note on ensiling characteristics of the tropical grass Setaria sphacelata var. splendida (Stapf).

Martins, J.M.; Fernandes, T.H.; Ferreira, L.M.A.
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
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The objective of this study was to evaluate the ensiling characteristics of Setaria sphacelata var. splendida (S. splendida) and to identify ensilability limiting factors of this tropical grass, locally produced.

Antioxidative properties of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves against DPPH, superoxide radical, hydroxyl radical and hypochlorous acid

Sousa, Carla; Vrchovská, Vendula; Valentão, Patricia; Ferreres, Federico; Pereira, José Alberto; Seabra, Rosa M.; Andrade, Paula B.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
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10 pages, 6 figures, 4 tables.-- Printed version published 2006.; The ability of the aqueous extract of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves to act as a scavenger of DPPH and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid) was investigated. A phytochemical study was also undertaken, and thirteen phenolic compounds and five organic acids were identified and quantified. Tronchuda cabbage extracts exhibited antioxidant capacity in a concentration-dependent manner in all assays, although some pro-oxidant effect was also noticed. The samples with higher phenolic and organic acid contents displayed the major antioxidant potentials.; The authors are grateful to Fundaçäo para a Ciência e Tecnologia (POCI/AGR/57399/2004) for financial support of this work. Vendula Vrchovská is grateful to the European Union Erasmus/Socrates II Programme for a grant (MSM 0021620822).; Peer reviewed

Phenolic Compounds in External Leaves of Tronchuda Cabbage (Brassica oleracea L. var. costata DC)

Ferreres, Federico; Valentão, Patricia; Llorach, Rafael; Pinheiro, Cristina; Cardoso, Lígia; Pereira, José Alberto; Sousa, Carla; Seabra, Rosa M.; Andrade, Paula B.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
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7 pages, 3 tables, 4 figures.; Glycosylated kaempferol derivatives from the external leaves of tronchuda cabbage (Brassica oleracea L. var. costata DC) characterized by reversed-phase HPLC-DAD-MS/MS-ESI were kaempferol 3-O-sophorotrioside-7-O-glucoside, kaempferol 3-O- (methoxycaffeoyl/caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-sophorotrioside-7-O-sophoroside, kaempferol 3-O-sophoroside-7-O-sophoroside, kaempferol 3-O-tetraglucoside-7-O-sophoroside, kaempferol 3-O-(sinapoyl/caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl/caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-sophorotrioside, kaempferol 3-O-(sinapoyl)sophoroside, kaempferol 3-O-(feruloyl)sophorotrioside, kaempferol 3-O-(feruloyl)sophoroside, kaempferol 3-O-sophoroside, and kaempferol 3-O-glucoside. These acylated derivatives are reported for the first time in nature, with the exception of kaempferol 3-O-(sinapoyl)sophoroside. Quantification of the identified compounds was achieved by HPLC-DAD and carried out in samples cultivated under conventional or organic practices and collected at different times. In general, samples from organic production exhibited higher total phenolics content than those from conventional practices collected in the same period.; We are grateful to Fundaçäo para a Ciência e Tecnologia (POCTI/AGR/57399/2004) for financial support of this work.; Peer reviewed

HPLC-DAD-MS/MS-ESI Screening of Phenolic Compounds in Pieris brassicae L. Reared on Brassica rapa var. rapa L

Ferreres, Federico; Valentão, Patricia; Pereira, José Alberto; Bento, Albino; Noites, Alexandra; Seabra, Rosa M.; Andrade, Paula B.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
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10 pages, 6 figures, 3 tables.; The phenolic profiles of cabbage white butterfly (Pieris brassicae L.; Lepidoptera: Pieridae) at different development stages (larvae, exuviae, and butterfly), its excrements, and its host plant Brassica rapa var. rapa L. were determined by high performance liquid chromatography− diode-array detector−mass spectrometry/mass spectrometry−electrospray ionization (HPLC-DAD-MS/MS-ESI). Twenty-five acylated and nonacylated flavonoid glycosides and ferulic and sinapic acids were identified in host plant, from which only 12 compounds were found in the excrements. In addition, the excrements showed the presence of sulfate flavonoids and other flavonoid glycosides that were not detected in the leaves. In the larvae kept without food for 12 h, only 3 compounds common to the plant material and 2 others, also present in the excrements, were characterized. The results indicate that deacylation, deglycosylation, and sulfating steps are involved in the metabolic process of P. brassicae and that its excrements may constitute a promising source of bioactive compounds, which could be used to take profit of this common pest of Brassica cultures.; The authors are grateful to Fundação para a Ciência e a Tecnologia (PTDC/AGR-AAM/64150/2006) for financial support of this work.; Peer reviewed

Multivariate Analysis of Tronchuda Cabbage (Brassica oleracea L. var. costata DC) Phenolics: Influence of Fertilizers

Sousa, Carla; Pereira, David M.; Pereira, José Alberto; Bento, Albino; Rodrigues, M. Angelo; Dopico-García, Sonia; Valentão, Patricia; Lopes, Graciliana; Ferreres, Federico; Seabra, Rosa M.; Andrade, Paula B.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
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9 pages, 5 figures, 2 tables.; A field experiment was carried out to investigate the effect of fertilization level on the phenolic composition of tronchuda cabbage (Brassica oleracea L. var. costata DC) external and internal leaves. Eight different plots were constituted: a control without fertilization, one with organic matter, and six experiments with conventional fertilizers (nitrogen, boron, and sulfur, two levels each). The phenolic compounds were analyzed by reversed-phase HPLC-DAD. External and internal leaves revealed distinct qualitative composition. In the internal leaves were found 15 phenolics (5 kaempferol and 10 cinnamic acid derivatives), whereas the external leaves presented 3-p-coumaroylquinic acid and 13 kaempferol derivatives. Principal component analysis (PCA) was applied to assess the relationships between phenolic compounds, agronomical practices, and harvesting time. Samples obtained with conventional practices were quite effectively separated from organic samples, for both types of leaves. In general, samples developed without any fertilization presented the highest phenolics amounts: external and internal leaves contained 1.4- and 4.6-fold more phenolic compounds than the ones that received conventional fertilizer...

Tronchuda Cabbage (Brassica oleracea L. var. costata DC): Scavenger of Reactive Nitrogen Species

Sousa, Carla; Valentão, Patricia; Ferreres, Federico; Seabra, Rosa M.; Andrade, Paula B.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
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7 pages, 6 figures, 4 tables.; The ability of tronchuda cabbage (Brassica oleracea L. var. costata DC) to act as a scavenger of the reactive nitrogen species nitric oxide and peroxynitrite was investigated. The aqueous extracts obtained from tronchuda cabbage seeds and from its external and internal leaves exhibited a concentration dependent scavenging capacity. The antioxidant potential observed against the two reactive species was as follows: seeds > external leaves > internal leaves. In order to establish a possible correlation with the chemical composition of the extracts, the activity of ascorbic and sinapic acids and kaempferol 3-O-rutinoside was also studied. Among the compounds tested, sinapic acid showed the strongest antioxidant activity against both species.; We are grateful to Fundaçäo para a Ciência e a Tecnologia (POCI/AGR/57399/2004) for financial support of this work.; Peer reviewed

Tronchuda cabbage (Brassica oleracea L. var. costata DC) seeds: Phytochemical characterization and antioxidant potential

Ferreres, Federico; Sousa, Carla; Valentão, Patricia; Seabra, Rosa M.; Pereira, José Alberto; Andrade, Paula B.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
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10 pages, 6 figures, 3 tables.; Tronchuda cabbage (Brassica oleracea L. var. costata DC) seeds were studied for their chemical composition and antioxidant capacity. Thirteen phenolic compounds were characterized and quantified by reversed-phase HPLC-DAD-MS/MS-ESI and HPLC-DAD, respectively: two sinapoylgentiobiose isomers, three sinapoylglucose isomers, kaempferol-3-(sinapoyl)sophorotrioside-7-glucoside, sinapoylcholine, kaempferol-3,7-diglucoside-4′-(sinapoyl)glucoside, three disinapoylgentiobiose isomers, 1,2,2′-trisinapoylgentiobiose and 1,2-disinapoylglucose. Seven organic acids (aconitic, citric, ascorbic, malic, quinic, shikimic and fumaric acids) were also identified and quantified by HPLC-UV. The aqueous extract of tronchuda cabbage seeds was investigated for its capacity to act as a scavenger of DPPH radical and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid), exhibiting antioxidant capacity in a concentration-dependent manner against all radicals. These results may be attributed to the high content of hydroxycinnamic derivatives and ascorbic acid.; The authors are grateful to Fundacäo para a Ciência e Tecnologia (POCI/AGR/57399/2004) for financial support of this work.; Peer reviewed

Screening of Antioxidant Compounds During Sprouting of Brassica oleracea L. var. costata DC

Sousa, Carla; Lopes, Graciliana; Pereira, David M.; Taveira, Marcos; Valentão, Patricia; Seabra, Rosa M.; Pereira, José Alberto; Baptista, Paula; Ferreres, Federico; Andrade, Paula B.
Fonte: Bentham Science Publishers Publicador: Bentham Science Publishers
Tipo: Artículo Formato: 259768 bytes; application/pdf
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10 pages.; The changes in antioxidant compounds of Brassica oleracea L. var. costata DC seeds were monitored during the first twelve days of seedling development. Sprouts were screened at time intervals of two days for phenolic compounds and organic acids. The identified phenolic compounds included esters of sinapic acid with glucose, gentiobiose and kaempferol, as well as sinapoylcholine. The organic acids were oxalic, aconitic, citric, pyruvic, malic, shikimic, and fumaric acids. During germination, a depletion of phenolic compounds was observed, although no qualitative changes were seen. Among individual compounds, kaempferol, choline and glucose esters of sinapic acid showed a marked decrease between days two and six, whereas the changes in gentiobiose esters of sinapic acid were smaller. The total organic acids content increased rapidly during the first four days, with less significant variations thereafter. Malic acid, the major organic acid found in sprouts, greatly contributed to this result though oxalic, pyruvic, and fumaric acids also increased in the same manner. In contrast, aconitic, citric and shikimic acids showed decreases between days two and twelve of germination.; Peer reviewed

Influence of Two Fertilization Regimens on the Amounts of Organic Acids and Phenolic Compounds of Tronchuda Cabbage (Brassica oleracea L. Var. costata DC)

Sousa, Carla; Valentão, Patricia; Rangel, Joana; Lopes, Graciliana; Pereira, José Alberto; Ferreres, Federico; Seabra, Rosa M.; Andrade, Paula B.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
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5 pages, 3 figures, 2 tables.; A phytochemical study was undertaken on tronchuda cabbage (Brassica oleracea L. var. costata DC) cultivated under conventional and organic practices and collected at different times. Six organic acids (aconitic, citric, ascorbic, malic, shikimic, and fumaric acids) were identified and quantified by HPLC-UV. Qualitative and quantitative differences were noted between internal and external leaves. Analysis of the phenolics of the internal leaves was achieved by HPLC-DAD, and the phenolic profile obtained was revealed to be distinct from that of the external leaves. By this means were identified and quantified 11 compounds: 3-p-coumaroylquinic acid, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-(sinapoyl)sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl)sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside, two isomeric forms of 1,2-disinapoylgentiobiose, 1-sinapoyl-2-feruloylgentiobiose, 1,2,2‘-trisinapoylgentiobiose, and 1,2‘-disinapoyl-2-feruloylgentiobiose. In general, internal leaves exhibited more constant chemical profiles.; We are grateful to the Fundaçäo para a Ciência e Tecnologia (POCI/AGR/57399/2004) for financial support of this work.; Peer reviewed

Valorization of Cauliflower (Brassica oleracea L. var. botrytis) By-Products as a Source of Antioxidant Phenolics

Llorach, Rafael; Espín de Gea, Juan Carlos; Tomás Barberán, Francisco; Ferreres, Federico
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
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7 pages, 4 figures, 3 tables.; The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH• and ABTS•+ radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.; This work has been partially supported by a grant from Spanish CICYT (Grant 1FD97-1809). R.LL. is holder of a contract from the same grant.; Peer reviewed

What if the UK has Joined the Euro in 1999? An Empirical Evaluation using a Global VAR

Pesaran, M. Hashem; Smith, L. Vanessa; Smith, Ron P.
Fonte: Universidade de Cambridge Publicador: Universidade de Cambridge
Formato: 584459 bytes; application/pdf; application/pdf
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We provide a conceptual framework to analysis counterfactual scenarios using macroeconometric models. We consider UK entry to the euro. We derive conditional probability distributions for the difference between the future realisations of variables of interest subject to UK entry restrictions being fully met over a given period, and the alternative realisations without the restrictions. Economic interdependence means that such policy evaluation must take account of international linkages and common factors that drive fluctuations across economies. We use the Global VAR developed by Dees, di Mauro, Pesaran and Smith (2005). The paper briefly describes the GVAR which has been estimated for 25 countries and the euro area over the period 1979-2003. It reports probability estimates that output will be higher and prices lower in the UK and the euro area as a result of entry. It examines the sensitivity of these results to a variety of assumptions about UK entry.

The Sequential Estimation of Subset VAR with Forgetting Factor and Intercept Variable

O'Neill, Terence; Penm, Jammie H C; Terrell, Richard
Fonte: World Scientific Publishing Company Publicador: World Scientific Publishing Company
Tipo: Artigo de Revista Científica
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In this paper we propose a forward time update algorithm to recursively estimate subset vector autoregressive models (including an intercept term) with a forgetting factor, using the exact window case. The proposed recursions cover, for the first time, subset vector autoregressive models (VAR) with a forgetting factor and an intercept variable. We then present two applications. In the first application we apply the proposed estimation algorithm to the quarterly aluminium prices on the London Metal Exchange. The findings show that the proposed algorithm can improve the forecasting performance. In the second application a bivariate system investigates the relationship between the Australian's All Ordinaries Share Price Index (SPI) futures and BHP share price (BHP). The proposed algorithm also introduces the Monte Carlo Integration approach into the proposed algorithm to generate error bands for the impulse responses. These results confirm that the SPI Granger causes BHP, but not vice versa.

Endocria y coancestria en poblaciones naturales de Anadenanthera colubrina var. cebil

Mazo,Tamara M; Barrandeguy,Maria E; Garcia,Maria V
Fonte: Revista de Ciencia y Tecnología Publicador: Revista de Ciencia y Tecnología
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 Português
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La endocria y la coancestria aumentan la homocigosis generando genotipos autocigotas sin afectar a las frecuencias alelicas. Puede considerarse que una muestra de loci selectivamente neutros permite hacer inferencias acerca del coeficiente de endocria de una poblacion porque sus efectos son expresados en todos los loci de cada individuo. Esto permite estudiar la posible presencia de depresion por endocria y su efecto sobre los valores fenotipicos de los caracteres poligenicos inferida desde loci neutrales a traves de la media de un caracter cuantitativo en k subpoblaciones y las estimas del indice de fijacion FITk. Se analizaron individuos adultos de Anadenanthera colubrina var. cebil. Se pudo concluir que los caracteres poligenicos analizados no presentaron reduccion de sus valores fenotipicos medios indicando ausencia de depresion por endocria, las poblaciones presentaron niveles bajos de coancestria y tamanos efectivos elevados en tanto que no se detecto aumento de homocigosis en los caracteres poligenicos analizados.

Sobre Phaseolus vulgaris var. aborigineus (Fabaceae) en Córdoba

Drewes,Susana Inés
Fonte: Boletín de la Sociedad Argentina de Botánica Publicador: Boletín de la Sociedad Argentina de Botánica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2006 Português
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El hallazgo de una población de poroto silvestre creciendo en el valle de Punilla confirma la presencia de Phaseolus vulgaris var. aborigineus en la provincia de Córdoba (Argentina), cuyo único antecedente era un ejemplar recolectado en el año 1903.

Tasa de crecimiento y patogenicidad de aislamientos de Diaporthe phaseolorum var. caulivora

Grijalba,P; del C Ridao,A
Fonte: Phyton (Buenos Aires) Publicador: Phyton (Buenos Aires)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 Português
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Diaporthe phaseolorum var. caulivora es el agente causal prevalente del cancro del tallo de la soja (CTS) en la Argentina; apareció principalmente en la subregión pampeana sur, pero también en zonas cálidas observándose diferencias en incidencia, severidad y virulencia. El objetivo del presente trabajo fue estudiar la tasa de crecimiento in vitro y la patogenicidad de aislamientos provenientes de plantas de soja, a diferentes temperaturas. Se seleccionaron 20 aislamientos de la provincia de Buenos Aires. Se midió la tasa diaria de crecimiento de nueve de ellos y de dos aislamientos de referencia, en agar papa dextrosa (APD) y distintas condiciones de luz/oscuridad, a cuatro temperaturas (15, 20, 25 y 30 °C). Mediante la técnica del escarbadiente se inocularon cuatro aislamientos en un cultivar de soja susceptible; las plantas inoculadas se incubaron en cámara de crecimiento a 15, 20 y 25 °C. Otros 17 aislamientos se inocularon en condiciones de campo e invernáculo. Se registró el porcentaje de plantas muertas. La tasa promedio de crecimiento de los aislamientos fue mayor a medida que aumentó la temperatura: a 15 °C fue similar entre ellos, a 20 °C hubo pequeñas diferencias, a 25 °C se diferenciaron dos grupos, mientras que a 30 °C no hubo crecimiento. Todos los aislamientos fueron patógenos. Las temperaturas de incubación indujeron diferentes porcentajes de mortandad: a 15 y 20 °C en cámara e invernáculo (a 20 °C) los porcentajes de plantas muertas fueron inferiores a 40%. Se sugiere que temperaturas inferiores a 20 °C no permitirían observar diferenciación fisiológica entre las dos variedades causantes de CTS. La similitud de crecimiento y el alto porcentaje de plantas muertas indicarían que la incidencia y severidad se deberían a las condiciones ambientales adecuadas para el desarrollo de la enfermedad.

La identidad de Schinus fasciculatus var. arenicola y rehabilitación de S. sinuatus (Anacardiaceae)

Steibel,Pedro E.; Troiani,Héctor O.
Fonte: Boletín de la Sociedad Argentina de Botánica Publicador: Boletín de la Sociedad Argentina de Botánica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2008 Português
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El estudio del tipo nomenclatural y de numerosos ejemplares de distintos herbarios; el análisis extensivo de las plantas en su hábitat en las regiones argentinas Central y Nordpatagónica y el examen de las plántulas y juveniles cultivados a partir de semillas, nos permiten establecer la identidad de S. fasciculatus var. arenicola (Hauman) F. A. Barkley, como un sinónimo de S. johnstonii F. A. Barkley. Esta variedad fue descripta originalmente por Hauman (1913) como S. dependens Ortega subsp. subintegra Engl. fo. arenicola Hauman, basada en un individuo juvenil. También la validez de Schinus sinuatus (Griseb.) Engl. es discutida. Ambos taxones se describen e ilustran, se dan las características morfológico-foliares en las distintas edades de las plantas y del tipo de rama que las porta y se incluye una clave para identificar las especies afines.

Estructura y Representatividad Genética Cloroplástica en Poblaciones Naturales de Anadenanthera colubrina var. cebil (Leguminosae) de Argentina

Goncalves,Alejandra L; Barrandeguy,María E; García,María V
Fonte: Boletín de la Sociedad Argentina de Botánica Publicador: Boletín de la Sociedad Argentina de Botánica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
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Anadenanthera colubrina var. cebil es una especie forestal nativa de Sudamérica cuya distribución en Argentina se restringe a las provincias fitogeográficas Paranaense y de las Yungas. Se estudiaron individuos pertenecientes a cuatro sitios experimentales mediante el análisis de cuatro loci cpSSRs. Se estimaron los niveles de diversidad genética, se determinó la estructura genética poblacional y se estimó la representatividad de la variabilidad genética cloroplástica. Los patrones de distribución de la diversidad genética cloroplástica contemporáneos en las poblaciones estudiadas resultan de la acción de la deriva genética. La ausencia de flujo génico mediado por semillas entre las poblaciones y la posible expansión histórica de los Bosques Secos Estacionales Neotropicales seguida de fragmentación habrían influido en la marcada estructuración genética poblacional detectada. Los sitios de muestreo de la provincia fitogeográfica Paranaense resultaron los más representativos de la variación genética total.

Ultraestructura de bambúes del género Dendrocalamus (Poaceae: Bambusoideae) cultivados en Costa Rica II: Dendrocalamus latiflorus var. latiflorus

Montiel,Mayra; Sánchez,Ethel
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2006 Português
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Mediante el microscopio electrónico de barrido se analizaron muestras de lámina foliar, culmo y rama, así como las brácteas del culmo y yemas de las ramas de Dendrocalamus latiflorus var. latiflorus. Se determinó la presencia en la epidermis abaxial de la lámina foliar de dos tipos de papilas céricas, esféricas y alargadas; éstas últimas rodeando los estomas de bajo domo. Sólo en la superficie adaxial de la nervadura central de la lámina foliar aparecen grandes tricomas en forma de gancho. En la zona abaxial de las brácteas del culmo, hay tricomas alargados y delgados similares a los de las brácteas de D. giganteus y las yemas de las ramas están cubiertas por tricomas bicelulares.