Conselho Nacional de Desenvolvimento Científico e Tecnológico / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Na agricultura moderna, apesar de serem empregadas as mais modernas tecnologias de cultivo de plantas e apesar dos progressos que têm sido feitos em programas de melhoramento, o máximo potencial das culturas de interesse agronômico está ainda longe de ser plenamente explorado. Assim, os bioestimulantes – uma categoria de produtos relativamente novos de diversas formulações, os quais afetam positivamente processos vitais de uma planta e apresentam grande potencial para uso na agricultura brasileira – podem ser uma alternativa promissora para os orizicultores. O objetivo deste trabalho foi conceituar e discutir o uso de agroquímicos de regulação hormonal e avaliar a influência de duas fontes bioestimulantes de aplicação foliar com Tecnologia AZAL5 (extrato de Ascophyllum nodosum) contendo silicato de potássio e micronutrientes, em aspectos nutricionais e vegetativos, na cultura do arroz de sequeiro. O primeiro capítulo teve a finalidade de, a partir de uma revisão bibliográfica, discutir o uso, os conceitos, os percalços e os benefícios de bioestimulantes, biorreguladores, bioativadores, ácidos húmicos e fúlvicos, bem como extrato de algas na agricultura brasileira. Os capítulos seguintes consistiram de dois experimentos (testes biológicos) em que foram avaliadas as duas fontes bioestimulantes – uma contendo silicato de potássio + molibdênio (Capítulo 2) e outra contendo silicato de potássio + zinco (Capítulo 3) – aplicadas via foliar na cultura do arroz. Os experimentos foram realizados em casa de vegetação, em vasos de 5 kg, com solo classificado como Neossolo Quartzarênico, utilizando-se a cultivar BRS Primavera. O delineamento experimental foi inteiramente casualizado, com quatro repetições, em arranjo 5 x 2. Os tratamentos consistiram de cinco doses (0; 1,50; 3,00; 4,50; 6,00 L ha-1), em dois modos de aplicação (parcelado e não parcelado). Foram avaliados: teores de clorofilas A, B e Total; teores foliares de silício e macro e micronutrientes; massa de matéria seca de raiz e parte aérea. Foram testadas as pressuposições estatísticas dos dados obtidos com os testes de normalidade de Kolmogorov-Smirnov e de homogeneidade das variâncias de Levene, ambos a 0,01 de significância e submetidos à análise de variância pelo teste de Tukey a 0,05 de significância. Os dados significativos para o fator quantitativo (doses) foram submetidos à análise de regressão. A aplicação da fonte bioestimulante contendo silicato de potássio + molibdênio alterou os teores foliares de K, Ca, S, Zn, Cu e a produção de massa de matéria seca de raiz; porém, não houve alteração nos teores foliares de N, P, Mg, Fe, Mn e Si, nos teores das clorofilas A, B e Total aos 55 DAE e na produção de massa de matéria seca da parte aérea em função das diferentes doses da fonte bioestimulante e dos diferentes modos de aplicação. A aplicação da fonte bioestimulante contendo silicato de potássio + zinco alterou os teores foliares de N, Ca, Mg, S, Zn e Cu e a produção de massa de matéria seca de raiz; contudo, não houve alteração nos teores foliares de Si, P, K, Fe e Mn, na produção de massa de matéria seca de parte aérea e nos teores das clorofilas A, B e Total aos 55 DAE em função das diferentes doses da fonte bioestimulante e dos diferentes modos de aplicação. / Despite the use of the most modern technologies of plant cultivation and the progress in breeding programs, the full potential of crops of agronomic interest is still far from being fully exploited. Biostimulants, a relatively new product category of various formulations, positively affect vital processes of plants and have shown great potential for use in the Brazilian agriculture, especially in the rice agriculture. The aim of this study is to discuss the use of hormonal regulation agrochemicals and assess the agronomic and nutritional efficiency of the foliar application of two biostimulants based on AZAL5 Technology (extract of Ascophyllum nodosum) containing potassium silicate and micronutrients. Chapter 1 draws on a review of the literature to discuss uses, concepts, benefits of and obstacles to biostimulants, bioregulators, bio-activators, humic and fulvic acids, as well as seaweed extract in the Brazilian agriculture. The following chapters report on two experiments (biological testing) that assessed both biostimulants – one containing potassium silicate + molybdenum (Chapter 2) and the other containing potassium silicate + zinc (Chapter 3) – applied to upland rice foliage. The experiments were carried out in a greenhouse, using 5-kg vases with Quartzipsamment soil and BRS Primavera cultivar. The experimental design was completely randomized, with four repetitions in a 5 x 2 structure. The treatments consisted of five doses (0; 1.50; 3.00; 4.50; 6.00 L ha-1) used in two modes of application (single application or in portions). The following parameters were evaluated: concentrations of chlorophyll A, B and Total; leaf content of macro and micronutrients and Si; and dry matter of root and aerial part. Statistical assumptions were assessed for the obtained data using Kolmogorov-Smirnov normality test and Levene’s test for homogeneity of variances, both set at 1%. Tukey’s test was used for analysis of variance and set at 5% significance. The significant data for the quantitative factor (doses) were included in a regression analysis. The application of biostimulant containing potassium silicate + molybdenum significantly changed the leaf content of K, Ca, S, Zn and Cu, as well as the production of dry matter of root. However, the leaf content of N, P, Mg, Fe, Mn and Si, the concentrations of chlorophyll A, B and Total, and the production of dry matter of aerial part were not significantly influenced by the different doses of said biostimulant and modes of application. The application of biostimulant containing potassium silicate + zinc significantly impacted on the leaf content of N, Ca, Mg, S, Zn and Cu, and on the production of dry matter of root. However, the leaf content of Si, P, K, Fe, and Mn, the production of dry matter of aerial part and the concentrations of chlorophyll A, B and Total were not significantly influenced by the different doses of said biostimulant applied in different modes. / Dissertação (Mestrado)

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No. of bitstreams: 2 Dissertação - Kátia Oliveira de Deus - 2015.pdf: 1298115 bytes, checksum: 25cbacec1dbe6f0e1109792b0b745ae4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-29 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The search for baked goods without gluten good physical, chemical and microbiological, and acceptance have provided various surveys. In order to replace the gluten in breads consumer medium for celiac disease patients, various strategies have been employed such as the use of hydrocolloids and enzymes. The aim of this study was to evaluate the feasibility of a technological standpoint, nutritional, microbiological and acceptance of gluten-free bun obtained from different proportions soy by-products (okara) and rice (bran and grain flour broken), type and dose of hydrocolloids, and dose of transglutaminase enzyme, seeking alternatives to supply the growing market for products for coeliacs, as well as enhancement of agro-industrial subproutos rice and soybeans. All formulations had good sensory acceptance by the tasters, but with 65 g 100 g-1 rice flour, 10 g 100 g-1 rice bran and 25 g 100 g-1 okara flour presented the best physical quality, obtaining the greater desirability compared to commercial standard, and was accepted sensory, with average grade above 6 (like slightly). Use of hydrocolloids increased the specific volume of loaves of bread and improved textural characteristics. The form of gluten bread with 2 g 100g-1 of xanthan gum showed the highest specific volume (1.82 cm3 g-1). The transglutaminase of microbial origin increased by 9 %, the specific volume of gluten loaves with 10 U of transglutaminase per g of protein, 16 % lower hardness, indicating softness of bread, which showed 5 % more cohesive than those without transglutaminase. Regarding the commercial form of the selected bread specific volume was obtained 11 % higher and 110 % softer than bread trade marks. The gluten form of bread made with 65 g 100 g-1 of rice flour, 10 g 100 g-1 of rice bran and 25 g 100 g-1 okara flour with the addition of 2 g 100 g-1 xanthan gum and 10 U transglutaminase per g protein, showed the best results in texture with 16 % less hardness, 5 % more cohesiveness, 9 % more bulk, more elastic 2 % and 10 % decrease in chewiness. The loaf of bread obtained sensory acceptance indicating their potential for marketing of food with 45.83 g 100g-1 protein, rich in dietary fiber (10.17 g 100 g-1), and 1.61 g 100 g-1 in soluble fiber and 8.57 g 100 g-1 in insoluble fiber, providing a healthier alternative for consumers of celiac disease patients. / A busca por produtos de panificação sem glúten de boa qualidade física, química e microbiológica, e aceitação vêm proporcionado várias pesquisas. No sentido de se substituir o glúten em pães-de-forma para consumidores portadores de doença celíaca, várias estratégias tem sido empregadas, tais como o uso de hidrocolóides e enzimas. O objetivo do presente trabalho foi avaliar a viabilidade do ponto de vista tecnológico, nutricional, microbiológico e aceitação do pão-de-forma sem glúten obtido a partir de diferentes proporções de co-produtos de soja (okara) e de arroz (farelo e farinha de grãos quebrados), tipo e dose de hidrocolóides, e dose de enzima transglutaminase, buscando alternativas para suprir o crescente mercado de produtos para celíacos, além da valorização dos subproutos agroindustriais do arroz e da soja. Todas as formulações tiveram boa aceitação sensorial por parte dos provadores, mas a com 65 g 100 g-1 de farinha de arroz, 10 g 100 g-1 de farelo de arroz e 25 g 100 g-1 de farinha de okara foi a que apresentou melhor qualidade física, obtendo a maior desejabilidade comparada com padrão comercial, e foi aceita sensorialmente, com nota média acima de 6 (gostei ligeiramente). O uso de hidrocolóides aumentou o volume específico dos pães-de-forma e melhorou as características texturais. O pão-de-forma sem glúten com 2 g 100 g-1 de goma xantana obteve o maior volume específico (1,82 cm3 g-1). A transglutaminase de origem microbiana aumentou 9 % o volume específico dos pães-de-forma sem glúten com 10 U de transglutaminase por g de proteína, 16 % menos dureza, indicando maior maciez do pão, que se mostraram 5 % mais coesos que os sem transglutaminase. Em relação aos comerciais o pão-de-forma selecionado obteve volume específico 11 % maior e 110 % mais macio que o pão comercial da marca A. O pão-de-forma sem glúten feito com 65 g 100 g-1 de farinha de arroz, 10 g 100 g-1 de farelo de arroz e 25 g 100 g-1 de farinha de okara com adição de 2 g 100 g-1 de goma xantana e 10 U de transglutaminase por g de proteína, foi o que apresentou melhores resultados em textura com 16 % menos dureza, 5 % mais coesividade, 9 % a mais de volume específico, 2 % mais elástico e 10 % de diminuição na mastigabilidade. O pão-de-forma obteve aceitação sensorial indicando o seu potencial para comercialização deste alimento, com 45,83 g 100 g-1 de proteínas, alto conteúdo de fibra alimentar (10,17 g 100 g-1), sendo 1,61 g 100 g-1 de fibra solúvel e 8,57 g 100 g-1 de fibra insolúvel, constituindo uma alternativa saudável para os consumidores portadores de doença celíaca.

by Wai Ching Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 154-159). / Abstracts in English and Chinese. / Statement --- p.ii / Acknowledgements --- p.iii / Abstract --- p.v / 摘要 --- p.vii / List of Abbreviations --- p.viii / Table of contents --- p.x / List of Tables --- p.xiv / List of Figures --- p.xv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature review --- p.4 / Chapter 2.1 --- Plant lectins --- p.4 / Chapter 2.1.1 --- Introduction --- p.4 / Chapter 2.1.2 --- Definition and subdivision of plant lectins --- p.4 / Chapter 2.2 --- Monocot mannose-binding lectins --- p.6 / Chapter 2.2.1 --- Occurrence and carbohydrate binding specificity --- p.6 / Chapter 2.2.2 --- Molecular structure and amino acid sequence --- p.7 / Chapter 2.2.3 --- "Molecular cloning, biosynthesis and post-translational modification" --- p.10 / Chapter 2.2.4 --- Mannose-binding lectins of Family Liliaceae --- p.11 / Chapter 2.2.4.1 --- Tulipa gesneriana lectins (TGL) --- p.12 / Chapter 2.2.4.2 --- Aloe arborescens lectins (AAL) --- p.13 / Chapter 2.2.4.3 --- Polygonatum multiflorum agglutinin (PMA) and lectin-related protein --- p.14 / Chapter 2.3 --- Polygonatum odoratum lectins (POL) --- p.15 / Chapter 2.3.1 --- Isolation and purification of POL from Yu Chu --- p.15 / Chapter 2.3.2 --- Agglutinating activity and anti-viral activities of POL --- p.17 / Chapter 2.3.3 --- Bacterial expression of POL in Escherichia coli --- p.18 / Chapter 2.4 --- Plant-based production of recombinant proteins --- p.20 / Chapter 2.4.1 --- Advantages of using plants as expression system --- p.20 / Chapter 2.4.2 --- Plant-derived recombinant proteins --- p.22 / Chapter 2.5 --- Expression of heterologous proteins in rice --- p.24 / Chapter 2.5.1 --- The facts of rice --- p.24 / Chapter 2.5.2 --- Rice storage proteins --- p.25 / Chapter 2.5.2 --- Expression of lysine-rich protein (LRP)/glutelin fusion proteinin rice seeds --- p.28 / Chapter 2.5.3 --- Expression of Galanthus nivalis agglutinin in rice --- p.29 / Chapter 2.6 --- Protein trafficking in plants --- p.30 / Chapter 2.6.1 --- Golgi-dependent pathways --- p.30 / Chapter 2.6.2 --- Golgi-independent pathway --- p.32 / Chapter 2.6.3 --- Expression of protein targeting determinants in tobacco plants and suspension cells --- p.33 / Chapter Chapter 3 --- Materials and Methods --- p.35 / Chapter 3.1 --- Introduction --- p.35 / Chapter 3.2 --- Chemcials --- p.35 / Chapter 3.3 --- Bacterial strains --- p.35 / Chapter 3.4 --- Cloning of POL cDNA --- p.36 / Chapter 3.4.1 --- Plant materials --- p.36 / Chapter 3.4.2 --- RNA extraction --- p.36 / Chapter 3.4.3 --- RT-PCR amplification of POL cDNA --- p.36 / Chapter 3.4.4 --- 5'RACE and 3'RACE --- p.38 / Chapter 3.4.5 --- Sequencing of POL cDNA --- p.39 / Chapter 3.5 --- Analysis of POL protein --- p.40 / Chapter 3.5.1 --- Protein extraction and Tricine-SDS PAGE --- p.40 / Chapter 3.5.2 --- Western blot analysis --- p.41 / Chapter 3.6 --- Chimeric gene construction --- p.42 / Chapter 3.6.1 --- Construction of the Cauliflower mosaic virus (CaMV)35S promoter/POL constructs --- p.44 / Chapter 3.6.2 --- Construction of the glutelin-1 promoter/POL constructs --- p.48 / Chapter 3.6.3 --- Sequence fidelity of chimeric genes --- p.55 / Chapter 3.7 --- Expression of transgenes in rice --- p.55 / Chapter 3.7.1 --- Plant materials --- p.55 / Chapter 3.7.2 --- Agrobacterium transformation --- p.55 / Chapter 3.7.3 --- Callus induction --- p.56 / Chapter 3.7.4 --- Agrobacterium culture and rice transformation --- p.56 / Chapter 3.7.5 --- Selection and regeneration of rice callus --- p.56 / Chapter 3.7.6 --- Isolation of genomic DNA --- p.58 / Chapter 3.7.7 --- Southern blot analysis --- p.58 / Chapter 3.7.8 --- Extraction of leaf total RNA --- p.59 / Chapter 3.7.9 --- Extraction of seed total RNA --- p.59 / Chapter 3.7.10 --- Northern blot analysis --- p.60 / Chapter 3.7.11 --- Protein extraction and Tricine SDS-PAGE --- p.60 / Chapter 3.7.12 --- Western blot analysis --- p.61 / Chapter 3.8 --- Cytopathic effect (CPE) reduction assay --- p.61 / Chapter 3.8.1 --- Protein extraction --- p.61 / Chapter 3.8.2 --- CPE reduction assay --- p.62 / Chapter 3.9 --- Confocal immunofluorescence --- p.63 / Chapter 3.9.1 --- Preparation of sections --- p.63 / Chapter 3.9.2 --- Labelling of fluorescence probes --- p.63 / Chapter 3.9.3 --- Image collection --- p.64 / Chapter Chapter 4 --- Results --- p.65 / Chapter 4.1 --- Cloning of POL cDNA from Yu Chu --- p.65 / Chapter 4.1.1 --- RNA extraction and partial POL cDNA amplification --- p.65 / Chapter 4.1.2 --- 5'RACE and 3'RACE --- p.67 / Chapter 4.1.3 --- Sequencing of POL cDNA --- p.68 / Chapter 4.1.4 --- Sequences comparison of POL and Liliaceae lectins --- p.75 / Chapter 4.2 --- Occurence of POL protein in Yu Chu plant --- p.77 / Chapter 4.3 --- Constitutional expression of POL in rice --- p.79 / Chapter 4.3.1 --- Construction of Cauliflower mosaic virus 35S promoter constructs --- p.80 / Chapter 4.3.2 --- Southern blot analysis --- p.82 / Chapter 4.3.3 --- Northern blot analysis --- p.84 / Chapter 4.3.4 --- Western blot analysis --- p.85 / Chapter 4.3.5 --- Western blot analysis of 35S/POL T1 plant --- p.87 / Chapter 4.4 --- Seed-specific expression of POL in rice --- p.88 / Chapter 4.4.1 --- Construction of the glutelin-1 promoter constructs --- p.89 / Chapter 4.4.2 --- Southern blot analysis --- p.92 / Chapter 4.4.3 --- Northern blot analysis --- p.96 / Chapter 4.4.4 --- Western blot analysis --- p.101 / Chapter 4.4.5 --- Western blot analysis of POL-BP-8O and POL-α-TIP T1 transgenic plants --- p.117 / Chapter 4.5 --- Cytopathic effect (CPE) reduction assay --- p.122 / Chapter 4.6 --- Confocal immunofluorescence studies --- p.125 / Chapter Chapter 5 --- Discussion --- p.134 / Chapter 5.1 --- Cloning of POL cDNA --- p.134 / Chapter 5.2 --- Analysis of constitutional expression of POL in rice --- p.136 / Chapter 5.3 --- Analysis of seed-specific expression of POL in rice --- p.138 / Chapter 5.4 --- Localization of POL in POL-BP-8O and POL-α-TIP transgenic rice seeds --- p.146 / Chapter 5.5 --- Cytopathic effect (CPE) reduction assay --- p.148 / Chapter 5.6 --- Future prospects --- p.151 / Chapter Chapter 6 --- Conclusion --- p.153

科学研究費補助金 研究種目:基盤研究(A)(2) 課題番号:08406002 研究代表者:山内 章 研究期間:1996-1997年度

Diversiteten bland gener som ger resistens (R) mot infektionssjukdomar är mycket stor i växtriket, särskilt i den effektorutlösta klassen av försvaret. Denna artikel beskriver interaktioner mellan växters effektorutlösta fösvar och patogeners effektorproteiner och undersöker evolutionära och genetiska mekanismer för uppkomsten av ny resistens. R-genprodukter har en typisk domänstruktur och interagerar både direkt och indirekt med patogeners effektorproteiner.Vid kontakt med ett effektorprotein utlöses en försvarsrespons som kan förhindra fortsatt patogen tillväxt. Flera genetiska mekanismer verkar samtidigt på R-gener, något som resulterar i en hög hastighet för uppkomst av nya R-varianter. Den intima samevolution som existerar hos många patogen-växtsystem formar det evolutionära utvecklingsmönstret av R-gener. Diversifierande positiv selektion via den biologiska kapprustningsmodellen och bevarande negativ frekvensberoende selektion är båda viktiga samevolutionära processer. Denna artikel indikerar att växters immunförsvar är anpassningsbart och robust, men belyser också den kunskapsbrist som råder inom resistensforskningen. / The diversity among genes conferring resistance (R) against infectious diseases is very high in the plant kingdom, especially in the effector triggered class of defense. This article describes the interactions between the plant effector triggered immunity and pathogen effectors and examines the evolutionary and genetic mechanisms for the emergence of new resistance. R gene products have a typical domain structure and interacts both directly and indirectly with pathogen effectors. Upon contact with an effector a defense response is triggered that may prevent the further pathogen growth. Multiple genetic mechanisms act simultaneously on the R-genes, which results in a rapid diversification of novel R variants. The intimate co-evolution of many existing plant-pathogen systems form the evolutionary pattern of R genes. Diversifying positive selection via the biological arms race model and conservative negative frequency-dependent selection are both important coevolutionary processes. This article indicates that the plant immune system is adaptive and robust, but also highlights the lack of knowledge in plant resistance research.

[EN] Rice (Oryza sativa L) is the main staple food for over 3 billion people (almost half the world population), and rice blast, caused by the fungus Magnaporthe oryzae, is the major threat for this crop worldwide, triggering also important losses in Spain some years. Some resistant cultivars have been released, mainly with complete resistance genes (Pi genes), but their resistance has not lasted long, due to the emergence of new virulent isolates. Therefore, the efforts for obtaining effective and durable resistance are focused nowadays on the use of partial resistance or a combination of partial and complete resistance. Partial resistance is a quantitative character, controlled by numerous genes of small effects (QTLs), that can interact among them, and usually also strongly with the environment. For a better knowledge of the population of M. oryzae in the Albufera region, and of the resistance genes and QTLs that might be effective in various Spanish rice growing regions, we tested along four years 31 differential varieties (isogenic lines carrying one different Pi gene each); these studies showed that fungus population can significantly change from one year to the other. On the other hand, we analyzed the genetics of resistance to M. oryzae in two populations derived from crosses between local and well adapted, although moderately susceptible, varieties (Sivert, JSendra), and allegedly resistant but poorly adapted varieties (CAN-6159, Gigante Vercelly. In F3 lines of both populations, the leaf and panicle susceptibility was determined in field trials under conditions that favour the infection: SixCNA lines were tested in a plot in the Albufera region, and those of JSxGV in four locations of Valencia, the Ebro River Delta, and Seville; inoculations in controlled conditions were also carried out in the second population. We compare the different methodologies for assessing susceptibility, and we discuss the environmental influence on it. 22 QTLs were detected in SIxCNA, and 61 in JSxGV, most of them in only one location. All four parents displayed partial resistance QTLs; but some QTLs showed small additive effects and, often, high dominance. At the same time, most of these QTLs exhibit significant interactions with other QTLs; and many of them co-localize with QTLs found in other studies. We have discovered substantial coincidences between QTLs that control incidence in panicle and those that determine leaf severity, thus supporting the hypothesis that there are common defence mechanisms in both organs. Chromosomal regions of interest for marker assisted breeding of resistant genotypes have been identified. / [ES] El arroz (Oryza sativa L.) es la principal fuente de alimentación para más de 3.000 millones de personas, casi la mitad de la población mundial, y la "piriculariosis", causada por el hongo Magnaporthe oryzae Couch, es la enfermedad que más pérdidas causa en este cultivo a escala mundial; también en España ha causado pérdidas importantes algunos años. Se han obtenido diversas variedades resistentes, principalmente al incorporar genes de resistencia completa (genes Pi), pero la mayoría se han vuelto susceptibles en pocos años al aparecer nuevos aislados más virulentos. Actualmente, para conseguir una resistencia efectiva y duradera, se busca incorporar resistencia parcial, o una combinación de ambos tipos de resistencia. La resistencia parcial es un carácter cuantitativo, controlado por numerosos genes de efecto pequeño (o QTLs), que pueden interaccionar entre ellos y que, con frecuencia, también lo hacen intensamente con el ambiente. Para conocer mejor la población del patógeno presente en la zona de la Albufera, y qué genes y QTLs de resistencia pueden ser efectivos en ésta y otras zonas arroceras de España, por un lado se ensayaron durante varios años 31 variedades diferenciales (líneas con un gen Pi diferente cada una); esto demostró que la estructura de la población del hongo puede variar significativamente con los años. Por otro lado, realizamos estudios genéticos sobre la resistencia a M. oryzae en dos poblaciones, procedentes del cruzamiento entre variedades locales, bien adaptadas pero moderadamente susceptibles (Sivert y JSendra) y variedades resistentes, pero no adaptadas (CNA-6159 y Gigante Vercelli). En líneas F3 de ambas poblaciones se determinó la resistencia en campo, en condiciones favorables para el ataque del hongo, en hojas y órganos productivos: en SixCNA, en una parcela de la Albufera, y en JSxGV, en 4 localidades de Valencia, el Delta del Ebro y Sevilla; en JSxGV, además, se realizaron inoculaciones en condiciones controladas. Se comparan los diferentes sistemas de medida de la susceptibilidad, y se discute la influencia ambiental en ella. Se detectaron 22 QTLs en SixCNA, y 61 QTLs en JSxGV, la mayoría de los cuales sólo se expresan en una localidad. Todos los parentales aportan alelos de resistencia; pero la mayoría de los QTLs identificados son de efectos pequeños y, a menudo, con un notable componente dominante. Al mismo tiempo, gran parte de estos QTLs presentan interacciones significativas con otros QTLs; y muchos de ellos co-localizan con QTLs identificados en otros estudios. Hemos encontrado bastantes coincidencias entre QTLs que controlan la incidencia en panículas y los que determinan la severidad en las hojas, apoyando la hipótesis de que existen mecanismos de defensa comunes en ambos órganos. Se han localizado regiones cromosómicas de interés que podrían ser utilizadas para la selección de genotipos resistentes. / [CAT] L'arròs (Oryza sativa L.) és la principal font d'alimentació per a més de 3.000 millions de persones, quasi la meitat de la població mundial, i la "piriculariosi", causada pel fong Magnaporthe oryzae Couch, és la malaltia que més pèrdues origina en aquest conreu a escala mundial; també a Espanya ha causat pèrdues importants alguns anys. S'han obtès diverses varietats resistents, principalment en incorporar gens de resistència completa (gens Pi), però la majoria s'han tornat susceptibles en pocs anys en aparèixer nous aïllats més virulents. Actualment, per aconseguir una resistència efectiva i duradora, es cerca incorporar resistència parcial, o una combinació de tots dos tipus de resistència. La resistència parcial és un caràcter quantitatiu, controlat per nombrosos gens d'efecte reduït (o QTLs), els quals poden interaccionar entre sí i que, sovint, també ho fan intensament amb l'ambient. Per conéixer millor la població del patògen present a la zona de l'Albufera, i quins gens i QTLs de resistència poden ser efectius a aquesta i a d'altres zones arrosseres d'Espanya, per una banda s'assajaren durant diversos anys 31 varietats diferencials (línies amb un gen Pi diferent cadascuna); això demostrà que l'estructura de la població del fong pot variejar significativament amb els anys. Per altra banda, realitzàrem estudis genètics sobre la resistència a M. oryzae en dues poblacions, procedents del encreuament entre varietats locals, adaptades però moderadament susceptibles (Sivert i JSendra) i varietats resistents però no adaptades (CNA-6159 i Gigante Vercelli). En línies F3 d'ambdues poblacions es determinà la resistència en camp, en condicions favorables per a l'atac del fong, en fulles i òrgans productius: en SixCNA, en una parcel·la de l'Albufera, i en JSxGV en quatre localitats de València, el Delta de l'Ebre i Sevilla; en JSxGV, a més a més, es realitzaren inoculacions en condicions controlades. Es comparen els diversos sistemes de mesura de la susceptibilidad, i es discuteix la influència ambiental en aquesta. Es detectaren 22 QTLs en SixCNA i 61 QTLs en JSxGV, la major part dels quals solament s'expressen a una localitat. Tots els parentals aporten al·lels de resistència; però alguns dels QTLs identificats són d'efectes reduïts i, freqüentment, amb un notable component dominant. Paral·lelament, gran part d'aquestos QTLs presenten interaccions significatives amb altres QTLs; i molts d'aquestos co-localitzen amb QTLs identificats en altres estudis. Hem trobat bastants coincidències entre QTLs que controlen la incidència en panícules i els que determinen la severitat a les fulles, recolzant la hipòtesi que existeixen mecanismes de defensa comuns en ambdós òrgans. S'han localitzat regions cromosòmiques d'interès que podrien ser emprades per a la selecció de genotipus resistents / Pérez Lotz, J. (2016). Análisis genético de la resistencia parcial a Magnaporthe oryzae en arroz (Oryza sativa) en varias poblaciones y ambientes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62582 / TESIS