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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Génomique comparative entre Muscadinia rotundifolia et Vitis vinifera pour faciliter l'identification de gènes de résistance / Comparative genomic between Muscadinia rotundifolia and Vitis vinifera to facilitate the resistance genes identification

Zah-Bi, Iritché Cyrille 06 January 2014 (has links)
Muscadinia rotundifolia est une espèce de la famille des Vitaceae. C’est un sous-genre du genre Vitis, le deuxième sous-genre étant celui des Euvitis qui comprend l’espèce cultivée Vitis vinifera (2n=38). M. rotundifolia (2n=40) est une source de résistance aux maladies très importante pour l’amélioration de la vigne. Son génome commence seulement à être décrit avec deux cartes génétiques récemment publiées. Ma thèse a consisté à utiliser des ressources génomiques chez M. rotundifolia cv Regale (banque BAC, collection de séquence d’extrémités de BAC ou BES et séquences de BACs) pour caractériser le génome de cette espèce en comparaison avec celui de V. vinifera. Les résultats obtenus ne montrent pas de différence importante entre les génomes des deux espèces en termes de composition du génome en bases (GC%), en séquences codantes ou en éléments répétés. De même, à une échelle globale, la famille de gènes NBS-LRR semble être similaire en termes de nombre et de balance entre les sous-familles. A une échelle plus fine cependant (carte physique et séquences de BAC), des remaniements relativement importants sont observés dans des régions portant cette famille de gènes, aboutissant parfois à des contenus différents en gènes, de région normalement homologues : duplication différentielles de gènes, présence/absence de gènes. / Muscadinia Rotundifolia is a species of the Vitaceae family. It is a sub-genus of the Vitis genus along with the Euvitis sub-genus, which the cultivated species Vitis vinifera belongs to. M. rotundifolia (2n=40) is a very important source of resistance to diseases in grapevine breeding programs. Its genome is only starting to be described with the recent publication of two genetic maps. The present study aimed at using M. rotundifolia cv Regale genomic resources (BAC library, BAC end sequences or BES, BAC sequences) in order to characterize the genome of this species in comparison with the genome of V. vinifera. The results showed that there is no striking difference between the two species in term of base composition (GC %), repeats frequency and gene space. The NBS LRR gene family also seems to be globally quite similar between the two species in terms of numbers and balance between subfamilies. At a finer scale (physical map and BAC sequence), frequent rearrangements are observed in genomic regions carrying the NBS-LRR gene family sometimes clearly associated with a different gene content between the two species in homologous regions: differential gene duplication, presence/absence of genes.
12

Producción de etileno en raíces de portainjertos de vid sometidos a distintas tasas de aplicación de riego / Ethylene production in roots of vine rootstocks submitted to different rates of irrigation

González Córdova, Fernanda Daniela January 2017 (has links)
Memoria para optar al Título Profesional de Ingeniera Agrónoma / Chile es el principal exportador de uva de mesa en el mundo, y a nivel nacional este frutal representa la mayor superficie plantada. Frecuentemente las raíces de vid deben desarrollarse en suelos con características físicas desfavorables, provocando una merma en el rendimiento. Una forma de abordar este problema es implementar el uso de portainjertos, sin embargo, no se dispone de suficientes antecedentes específicos que indiquen cómo éstos responden a distintas condiciones del suelo. Uno de los factores a considerar es la humedad del suelo, que, dependiendo de su nivel, puede inducir en las raíces respuestas asociadas al crecimiento y desarrollo o también a la producción de sustancias como el etileno. En consecuencia, se requiere más información sobre el comportamiento de los portainjertos frente a distintos niveles de riego. Los objetivos planteados en esta investigación fueron, determinar la producción de etileno en raíces de tres portainjertos de vid en tres condiciones de humedad del suelo, y evaluar el efecto de la cantidad de agua sobre el desarrollo de brotes y el desarrollo radical de estos portainjertos. El estudio se llevó a cabo en macetas de 20 L, con una mezcla de arena gruesa, perlita y suelo franco arenoso. Los tratamientos correspondieron a la combinación de portainjerto (“Harmony”, “Paulsen 1103” y “Ramsey”) y humedad del suelo (50%, 100% y 150 % de la “capacidad de maceta” de Harmony, efectuando riegos mediante goteros con descargas de 2, 4 y 6 L h-1 respectivamente). Se utilizó un diseño experimental completamente aleatorizado con estructura factorial de tratamiento 3x3 y seis repeticiones. Se evaluó el etileno producido por las raíces, el crecimiento semanal de brotes y la masa final de raíces. Los resultados no mostraron diferencias en el etileno emitido por raíces de “Harmony”, “Paulsen 1103” y “Ramsey” en ninguna fecha de evaluación, independiente del nivel de riego. La longitud final de brotes solo presentó diferencias entre los niveles de riego, siendo el efectuado a 150% de la “capacidad de maceta” el que mostró mayor crecimiento, independiente del portainjerto utilizado. A partir de la tercera semana se evidenciaron diferencias en el largo de brotes entre tratamientos. “Ramsey” regado a 50% de la “capacidad de maceta” se destacó por presentar los menores valores, permaneciendo así hasta el final de la temporada, mientras que “Paulsen 1103” y “Ramsey” regados a 150% de la “capacidad de maceta” mostraron los mayores crecimientos de brotes desde la sexta semana de evaluación. Los sistemas radicales de los tres portainjertos no presentaron diferencias en masa fresca y seca, independiente del agua suministrada.
13

Biosynthesis of flavonoids in grapevines (Vitis vinifera L.) / Mark Downey.

Downey, Mark Oliver January 2004 (has links)
Bibliography: p. 227-253. / xvii, 254 p. : ill. (chiefly col.), photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This project sought to examine the spatial and temporal distribution, as well as the composition, of the flavan-3-ols, proanthocyanidins and flavonols in winegrapes throughout berry development. In addition, the author sought to explore how modifying bunch exposure to light would impact upon flavonoid biosynthesis in the grape berry by comparing the flavonoid composition of shaded and exposed grapes. The expression of key genes in the flavonoid biosynthetic pathway was also investigated to understand how the pathway is regulated during berry development. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Wine and Horticulture, 2004
14

Response of grapevines to partial drying of the root system /

Dry, P. R. January 1997 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1998. / Includes bibliographical references (p. 261-273).
15

Efecto de distintos niveles de deshoje sobre la fotoinhibición en pieles de bayas de la cepa sauvignon blanc (Vitis vinífera L.)

Opazo Pavez, Rodrigo Antonio January 2013 (has links)
Tesis para optar al Grado de Magíster en Enología y Vitivinicultura / La absorción de la luz ocurre gracias a los pigmentos de clorofila del tipo a y b, que se asocian a complejos de proteínas en los tilacoides, denominados fotosistema I y II (PSI y PSII). En los fotosistemas están presentes los carotenoides que pueden absorber la radiación luminosa, actuando como pigmento auxiliar, pero también tienen un papel transcendental en la fotoprotección. Prácticas como el deshoje, que buscan mejorar las condiciones de aireación e iluminación de los racimos, generan diferentes comportamientos en las pielesde las bayas. En este trabajo se realizaron dos ensayos, uno con racimos con exposición Este y otro con exposición Oeste, en donde se evaluaron los efectos de los tratamientos de oscuridad, sin deshoje, deshoje al estado de tamaño arveja y deshojes en envero, sobre el comportamientode la fotosíntesis, composición de pigmentos de clorofilas a y b, y carotenoides en las pieles de las bayas de la cepa Sauvignon Blanc. Los distintos regímenes lumínicos afectaron con diferencias significativas la morfología de la baya, durante su crecimiento y desarrollo.En relación a la fotosíntesis, en ambos ensayos,los tratamientos deshojados presentaron fotoinhibición desde posenvero, en donde los tratamientos con deshoje en envero presentaron Fv/Fm más bajos, con valores que oscilaron entre 0,79 y 0,38 en el ensayo Este, y entre 0,37 y 0,29 en el ensayo Oeste.Al comienzo de los ensayos, la concentración de las clorofilas presentaron diferencias significativas, fundamentalmente en el ensayo de la orientación Este, luego las clorofilas disminuyeron en los cuatro tratamientos hasta el final de la temporada. Los carotenoides totales aumentaron el contenido en el tiempo, además los tratamientos provocaron una activacióndel ciclo de las xantofilas en los fotosistemas. El alto grado de exposición de los racimos provocó dañosen los fotosistemas, evidenciados en la disminución de Fv/Fm. Sin embargo, aumentó el contenido de carotenoides al final de la temporada, lo que puede ser beneficioso, ya que podría conducir a la mayor formación de compuestos aromáticos. / The absorption of light occurs due to the chlorophyll pigments of the type a and b, which are associated with protein complexes in thylakoids, called photosystem I and II (PSI and PSII). Within the photosystems it is possible to find the Carotenoids. Carotenoids can absorb light radiation, acting as auxiliary pigment, but also having a transcendental role in photoprotection process. Procedures such as defoliation, seeking to improve the conditions of ventilation and illumination of clusters, generate different behaviors in the skin of the berries.In this work, two experiments were done, one bunch with East orientation and one with West orientation. The researchers evaluated the effect of the treatment dark, without leaf removal, leaf removal to pea state and leaf removal from veraison, on the behavior of photosynthesis and pigment composition of chlorophylls a and b, and carotenoids in the skins of the berries of Sauvignon Blanc. The different light patterns, affected with significant differences in the morphology of the berry, during their growth and development. In relation to photosynthesis, in both trials showed photoinhibition treatments from postenvero leafless, where defoliation treatments at veraison showed Fv/Fm lower, with values ranging between 0,79 and 0,38 in the test this, and between 0,37 and 0,29 in the Western assay. At the beginning of the trials, the chlorophylls showed significant differences, mainly in the trial with east orientation. Then, the chlorophylls decreased in the four treatments until the end of the season. Total Carotenoids increased their content during the time. Morover, treatments caused the activation of xanthophylls cycle in photosynthetic systems. High exposure of clusters caused damage photosynthetic systems, as evidenced by declining Fv/Fm. However, increased the carotenoid content at the end of the season, which be can beneficial as it could lead to increased formation of aromatics.
16

Diagnose molecular do cancro bacteriano da videira causado por Xanthomonas campestris pv. viticola

Trindade, Loiselene Carvalho da January 2007 (has links)
Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Fitopatologia, 2007. / Submitted by Luanna Maia (luanna@bce.unb.br) on 2009-03-09T12:48:41Z No. of bitstreams: 1 Tese_Loiselene Carvalho da Trindade.pdf: 3690145 bytes, checksum: 0c6bb1644820c1ea99648a03adf90c94 (MD5) / Approved for entry into archive by Luanna Maia(luanna@bce.unb.br) on 2009-03-09T16:04:29Z (GMT) No. of bitstreams: 1 Tese_Loiselene Carvalho da Trindade.pdf: 3690145 bytes, checksum: 0c6bb1644820c1ea99648a03adf90c94 (MD5) / Made available in DSpace on 2009-03-09T16:04:29Z (GMT). No. of bitstreams: 1 Tese_Loiselene Carvalho da Trindade.pdf: 3690145 bytes, checksum: 0c6bb1644820c1ea99648a03adf90c94 (MD5) / A bactéria Xanthomonas campestris pv. viticola (Nayudu) Dye, agente do cancro bacteriano da videira, foi relatada pela primeira vez nas áreas irrigadas do Submédio do Vale São Francisco em Petrolina, Pernambuco, em 1998. A doença também foi identificada em Juazeiro, Bahia, e posteriormente no Piauí, no Ceará, Roraima e Goiás. O uso de material propagativo livre do patógeno tornou-se uma preocupação, uma vez que a ocorrência da bacteriose ainda esta restrita a essas regiões no país e existe o risco de disseminação para outras regiões produtoras no sul e sudeste do Brasil. Com o objetivo de desenvolver um método molecular para detecção e identificação dessa bactéria, três oligonucleotídeos iniciadores foram desenhados com base no seqüenciamento parcial do gene hrpB. As combinações de iniciadores Xcv1F/Xcv3R e RST2/Xcv3R foram testados quanto à especificidade e sensibilidade para detecção do DNA de X. campestris pv. viticola. Com os dois pares de iniciadores, a amplificação foi positiva com o DNA das 44 estirpes de X. campestris pv. viticola testados, com quatro estirpes da patovar mangiferaeindicae, e cinco estirpes de X. axonopodis pv. passiflorae. Contudo, a digestão dos produtos de PCR com HaeIII permitiu diferenciar as estirpes das três patovares. Nenhum dos dois pares de iniciadores amplificou o DNA de videira, de 20 bactérias não patogênicas da flora da videira, e de nove estirpes de outros sete gêneros de bactérias fitopatogênicas. A sensibilidade dos iniciadores Xcv1F/Xcv3R e RST2/Xcv3R foi de 10 pg e 1 pg de DNA purificado de X. campestris pv. viticola, respectivamente. O limiar de detecção de RST2/Xcv3R foi de 104 UFC/ml, mas empregando-se um segundo ciclo de amplificação com o iniciador interno Xcv1F, esse limiar foi reduzido para 102 UFC/ml. Os iniciadores foram testados na detecção da bactéria em pecíolos inoculados com a estirpe UnB 1186 e embora não se tenha tido sucesso na PCR com o extrato do macerado do tecido sintomático, foi possível detectar o patógeno usando-se lavado de placas após o crescimento por 72 h ou a partir de uma única colônia diluída em 200 l de água. A identidade da bactéria foi confirmada pela análise de RFLP, que gerou o padrão típico de X. campestris pv. viticola. Com o uso de nested-BIO-PCR utilizando dois ciclos de amplificação com os iniciadores RST2/Xcv3R e Xcv1F/Xcv3R foi possível detectar X. campestris pv. viticola em plantas assintomáticas e sintomáticas, coletadas em março de 2007, em Petrolina, PE. xiii Este método mostrou-se mais eficiente que a detecção direta, ou seja, sem uma etapa de enriquecimento em meio de cultura. Além disso, foi possível reduzir para 72 horas o tempo para detecção e identificação de X. campestris pv. viticola, tempo reduzido se comparado aos métodos convencionais. A alta similaridade observada entre as duas patovares, viticola e mangiferaeindicae de X. campestris foi comprovada através da análise de seqüências de nucleotídeos de diferentes regiões genômicas, ITS, 16S rRNA, hrpB6 e o gene do citocromo “b561-like”. Os resultados também sugeriram que as duas patovares estariam mais próximas filogeneticamente a X. campestris e X. axonopodis. Testes de inoculação cruzada em videira e mangueira mostraram a capacidade de X. campestris pv. mangiferaeindicae de infectar plantas de videira e confirmaram a patogenicidade de X. campestris pv. viticola à mangueira, quando a inoculação é feita por infiltração foliar. O estudo dos perfis plasmideais mostrou variabilidade entre as estirpes em relação ao número e tamanho dos plasmídeos, sendo o primeiro relato da presença de plasmídeos em X. campestris pv. viticola. _______________________________________________________________________________ ABSTRACT / The bacterium Xanthomonas campestris pv. viticola (Nayudu) Dye, causal agent of grapevine bacterial canker, was first detected in Brazil in the irrigated areas of the São Francisco river basin, in Petrolina, State of Pernambuco, in 1998. The disease was also reported in Juazeiro, Bahia and later in the states of Piauí, Ceará, Roraima and Goiás. The use of pathogen-free propagative material has become an important concern, considering the restricted occurrence of this pathogen in the country and the risk of dissemination to other grapevine production regions in the south and southeast of the country. In order to develop a molecular method for detection and identification of this pathogen, three primers were designed based on the partial sequences of the hrpB gene. The primers combinations Xcv1F/Xcv3R and RST2/Xcv3R were tested for specificity and sensitivity in detecting X. campestris pv. viticola DNA. With the two sets of primers, amplification was positive with all 44 X. campestris pv. viticola isolates tested, 4 isolates of pathovar mangiferaeindicae and 5 of X. axonopodis pv. passiflorae. Digestion of PCR products with HaeIII allowed differentiation of these 3 pathovars. None of the primer pairs were able to amplify grapevine DNA, DNA from 20 non pathogenic bacterium from the grapevine microflora, or DNA from 9 isolates from 7 genera of plant pathogenic bacteria. Sensitivity of the primers Xcv1F/Xcv3R and RST2/Xcv3R was 10 pg and 1 pg of purified X. campestris pv. viticola DNA, respectively. The detection limit for RST2/Xcv3R was 104 UFC/ml, but this limit could be lowered to 102 CFU/ml with a second round of amplification using the internal primer Xcv1F. The primers were tested for detecting of X. campestris pv. viticola in grapevine petioles previously inoculated with strain UnB 1186, and although amplification was not possible using extracts of macerated plant tissue, detection was possible using agar plate washes after 72 h of growth, or from a single colony diluted in 200 l of water. Using Nested-BIO-PCR with two amplification rounds with RST2/Xcv3R and Xcv1F/Xcv3R primers, it was possible to detect X. campestris pv. viticola in both symptomatic and asymptomatic plants. This method was more effective than a method that employed direct detection from boiled macerated extracts with no previous enrichment on culture medium. The use of BIO-PCR reduced the time needed for detecting and identifying X. campestris pv. viticola to 72 hours, when compared to more traditional diagnostic methods. xv The high similarity observed between the two pathovars of X. campestris, viticola and mangiferaeindicae was cnfirmed by the analysis of nucleotide sequences from different genomic regions, ITS, 16S rRNA, hrpB6 and the cytochrome b561-like gene. The results also suggested that these two pathovars are phylogenetically related to X. campestris and X. axonopodis. Cross inoculation tests on grapevine and mango plants inoculation, showed the ability of X. campestris pv. mangiferaeindicae to infect grapevine and confirmed the pathogenicity of X. campestris pv. viticola to mango plants, when using the infiltration technique. Plasmid DNA extractions showed variability among strains of the two pathovars in plasmid number and size. This is the first report of plasmid occurrence in X. campestris pv. viticola.
17

Studium fyziologických podmínek růstu révy vinné Vitis vinifera L. a dal- ších rostlin

Fišerová, Helena January 1996 (has links)
No description available.
18

Efecto de la carga frutal en la producción y calidad en uva de mesa "Sultanina"

Pinochet Zúñiga, Carolina Patricia January 2011 (has links)
No disponible a texto completo / Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Fruticultura / En la temporada 2003 – 2004, en la Comuna de Nancagua, se realizó un estudio para determinar el efecto de la carga frutal sobre la producción y calidad en uva de mesa variedad Sultanina (Thompson Seedless). Se evaluó distintos niveles de carga frutal, ajustando el número de racimos por planta y número de bayas por racimo. El número de racimos fue ajustado a 20; 30; 40; 50; 60 ó 70 racimos por planta, durante la labor de “descarga de racimos”; antes de plena flor. Posteriormente, en el momento de “arreglo de racimos”, con bayas entre 4 y 5 mm de diámetro, se ajustó el número de bayas por racimo en rangos de 80 a 120 bayas, 120 a 160 bayas y 160 a 200 bayas, rangos bajo (B), medio (M) y alto (A) respectivamente. El ensayo fue completamente al azar, con arreglo factorial de tratamientos 6 x 3, con un total de 18 tratamientos, siendo la unidad experimental la planta. Existió un efecto significativo de la carga frutal sobre el rendimiento por planta, aumentando en el mayor nivel de carga frutal; similar respuesta, pero inversa, se obtuvo en el tamaño de bayas. El número de bayas por racimo afectó a la producción total y exportable de la planta, al peso promedio de racimos y a la proporción de desecho de fruta. Sin embargo, para sólidos solubles, acidez titulable, firmeza, número de brotes iniciales y finales, tanto el número de racimos por planta como número de bayas por racimo no afectaron estos parámetros, lo mismo para área sección transversal inicial y final del tronco. La carga frutal y número de bayas, determinados en este ensayo como óptimo, para cosechar fruta de exportación de buena calidad y sin retrasar la cosecha, fue de 60 racimos por planta, con un rango de entre 120 a 160 bayas por racimo; haciéndose más difícil el manejo operacional en la descarga y arreglo de racimo en la medida que se incrementan los niveles de carga. / In the season 2003 - 2004, in the Commune of Nancagua, a study was conducted in order of to determine the effect of crop load on yield of Thompson Seedless table grape (Sultanina). We evaluated different levels of crop load, as bunches per plant and berries per cluster. The cluster per plant was set to 20; 30; 40; 50; 60 or 70, during cluster thinning and before full bloom. Later, during berry hand thinning berries per cluster was adjusted between 80 and 200, obtaining three distinct ranges low (B), medium (M) and high (A). Crop load significantly affected yield per plant, increasing it as crop load was higher; an inverse behaviur was obtained for size berry. Berries per bunch proportionally affected to total yield and export per plant, bunch weight and discarded fruit. However, soluble solids, acidity, firmness, shoots number, and trunk cross-sectional area at the beginning and at the end of the season were not affected by crop load. In the optimum crop load of this vineyard was established at 60 clusters per plant, with clusters range of 120 to 160 berries per cluster. That crop load permits harvest is high quality export fruit without delaying the harvest; a higher levels of crop load cluster and berry thinning of to be regimens amount of it labor.
19

Efecto del lixiviado de riego de cultivos utilizados como cobertura sobre vid de mesa de un año de edad

Laborie Guerra, Denisse Alessandra Bernabé January 2011 (has links)
Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Fitotecnia / En el Valle de Copiapó, las condiciones climáticas se presentan favorables para el desarrollo de la vid (Vitis vinífera), sin embargo, los suelos de la zona son sensibles al deterioro físico producto del manejo agrícola (alta intensidad de uso y bajos niveles de materia orgánica). Con respecto al último punto se han evaluado diferentes manejos entre los cuales se encuentra el uso de cultivos de cobertura, sin embargo no existen antecedentes de efectos alelopáticos generados sobre vides. Por este motivo, se llevó a cabo el presente estudio donde se evaluó el efecto de lixiviados provenientes del agua de riego de cebada, haba, mostaza y sordán sobre el crecimiento de vid variedad Sultanina de un año de edad. El ensayo se realizó con un diseño experimental completamente al azar y contempló 5 tratamientos conformados por plantas de vid que crecieron en contenedores individuales, las cuales se regaron con el lixiviado de riego proveniente de los cultivos de cobertura antes mencionados y sembrados en forma independiente a las plantas de vid, además de un testigo sin cultivo; cuando éstos alcanzaron el 50% de floración, fueron segados y dejados sobre la misma superficie continuando el riego, utilizando el lixiviado correspondiente, hasta que las vides cesaron de crecer. Se midió altura de planta, diámetro del tronco, número de hojas y longitud de brotes. Además, al finalizar el periodo de crecimiento de la vid se midió materia fresca y seca de la parte aérea y de raíces. Los resultados indican que existieron reducciones estadísticas significativas en longitud de brotes y número de hojas en las plantas de vid para los tratamientos de cebada, mostaza y sordán, manifestándose estas diferencias en etapas previas y posteriores al corte de los cultivos. También se observó una menor acumulación de materia fresca y seca en brotes de vid en el tratamiento de cebada, sin detectar diferencias en peso de las raíces. Las variables altura de planta y diámetro del tronco no presentaron diferencias estadísticas. Debido a que en este ensayo no existió competencia entre los cultivos y las vides, el efecto de reducción del crecimiento se atribuiría a algún tipo de exudado generado por los cultivos de cobertura y/o residuos de éstos, compuestos que al ser lixiviados por el agua de riego afectarían el crecimiento de la vid. / In the Copiapo valley, climatic conditions are favorable for vine agriculture (Vitis vinífera), however, the soils of the area are very sensitive to physical damage because of agriculture management, such us high intensity use and low levels of organic matter in the soil). The latter effect has been study with several kinds of management, nevertheless, there is no information of the allelopathic effects produced in vine. For this reason a study was developed to evaluate the effect of leachate irrigation water from barley, beans, mustard and sordan on the growth of a one year old ‘Sultanina’ vine variety. This work was performed using a completely randomized design with five treatments. In each treatment vines were grown in individual containers and they were irrigated with the differents leachates of the cover crops, and an untreated sample. Once the plants reached the 50% flowering state, they were harvested and left in the containers with each leachate irrigation until the vines stopped growing. Several measuring parameters were obtained in the course of the experiment like plant height, stem diameter, leaf number and shoot length. At the end of growing period fresh and dry weigth of foliage and roots were measured. Results showed statistically significant reductions in shoot length and leaf number for the barley, mustard and sordan treatments, which were recorded before and after the crops harvest. We also observed a reduced accumulation of fresh and dry weight in vine shoots irrigated with barley leachate, with no differences in root weight. Also, plant height and stem diameter were not statistically different compared with the control. Because in this trial no competition occurred between the crops and vines, slow vine growth was attributed to some type of exudate or residue produced by the plants that affect vine growth when irrigated with this leachate.
20

Development of a reporter system for the analysis of xylophilus ampelinus type III secreted effectors

Nyembe, Nompumelelo Philile Praiseworth January 2014 (has links)
>Magister Scientiae - MSc / Xylophilus ampelinus, the causal agent of bacterial blight and canker of grapevines, has long been a threat to the table grape industry in the Western Cape, leading to severe economic losses due to the reduced productivity and shortened lifespan of infected grapevines. Very little is known about the genetic makeup of the organism, especially with regard to the factors that contribute to its pathogenicity. Generally, bacterial pathogens directly inject the effector proteins into host cells via Type III secretion system (T3SS). In the attempts to identify and characterize the T3 secreted effectors, different reporter plasmid systems have been used to study the secretion and translocation mechanisms the effectors employ during pathogenicity. The aim of the study was to generate a T3 reporter plasmid system for X. ampelinus that will allow the identification and classification of potential pathogenicity factors as members of the Type III secretion class of effectors. First, the avrBs1 family genes avrBs1 and avrA were identified and characterized. The two avirulence genes induced HR on Nicotiana tabacum leaves. Due to the relatedness of the X. ampelinus avr sequences to those of xanthomonads, and the fact that Xanthomonas avrBs1 has been successfully used in a number T3 effector studies, it was decided to construct an X. ampelinus T3 effector reporter vector based on the avrBs1 gene. The minimal segment of the X. ampelinus AvrBs1 protein C-terminus, sufficient for recognition inside host cells and also responsible for HR-induction was identified and characterized using Agrobacterium-mediated transient expression. The AvrBs157-413 HR-inducing domain was cloned in-frame with the 3x FLAG epitope, into a broad-host range vector. To test the reporter vector, the full length avrBs1 sequences of X. ampelinus and Xanthomonas campestris pv. campestris were cloned ahead of the 3x FLAG epitope and the constructs were transferred into XaΔavrBs1 knockout mutant to test for protein secretion. Furthermore, the reporter construct was tested for Type III protein translocation on Bs1 resistant pepper cultivar STAR 6657. Optimization of protein secretion and translocation assays is however required for the improved results. This might include the application of an alternative protein tag to identify candidate X. ampelinus T3SS effectors.

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