As the global population rises, the demand for food increases which underscores a need for improvement in food security. Disease pressures are a major concern surrounding sustainable agriculture. Static crop populations, containing little to no genetic diversity, are vulnerable to diverse pathogen populations. Wild relatives of crop plants are a reservoir for new disease resistance traits that can be introgressed into cultivated crops. The identification of novel disease resistance is of paramount importance because pathogen co-evolution is not only defeating current resistance genes (R genes) but chemical controls as well. Phytophthora sojae (P. sojae), the causal agent of Phytophthora root and stem rot disease, reduces soybean harvests worldwide. We developed an approach to screen for new R genes that recognize core effectors from P. sojae. We expect R genes identified by these screens to be durable because P. sojae requires core effectors for virulence. We utilized effector-based screening to probe Glycine soja germplasm with core RXLR effectors from P. sojae to search for novel R genes. We developed segregating populations from crosses of P. sojae resistant G. soja germplasm with susceptible G. max cultivar Williams to determine inheritance of potential R genes in germplasm that responded to core effectors. We are using marker assisted breeding to map disease resistance traits in recombinant inbred (RI) lines. To better understand pathosystems, we examined host resistance and susceptibility using bioinformatics. We analyzed the interaction between Arabidopsis thaliana ecotype Col-0 and Hyaloperonospora arabidopsidis isolate Emwa1 using a publicly available RNA time-course experiment. We describe a new algorithm to sort genes into time-point specific clusters using activation and repression parameters. Gene ontology annotations were used to identify defense genes with unique expression profiles, and A. thaliana null mutants for these genes were significantly more susceptible to Emwa1 than wild-type. We plan to use these tools to rapidly identify and guide introgression of durable disease resistance into crop species. / Ph. D.

Phytoalexins and phytoanticipins are antimicrobial natural products involved in plant defence pathways against plant pathogens and other stresses. Most cruciferous phytoalexins are indole containing compounds with various side chains (dithiocarbamates, isothiocyanate, isonitrile, acetonitriles etc.). Many phytoanticipins of crucifers are glucosinolates and their metabolites, which have diverse structures and precursors, including aliphatic, phenyl or indolyl containing amino acids. Indole glucosinolates are derived from tryptophan, which is also a biosynthetic precursor to cruciferous phytoalexins, however the biosynthetic relationship between cruciferous phytoalexins and indole glucosinolates has not been clarified. In this work, investigation of antifungal metabolites from wild crucifers, synthesis of antifungal metabolites and potential perdeuterated biosynthetic precursors, biosynthesis of metabolites of salt cress and that of rutabaga will be described. Investigation of the wild crucifers Brassica tournefortii, Crambe abyssinica, Diplotaxis tenuifolia and Diplotaxis tenuisiliqua for production of elicited antifungal metabolites, resulted in the discovery of a new phytoalexin, 1ꞌ,4ꞌ-dimethoxyindolyl-3ꞌ-acetonitrile, from D. tenuisiliqua. 1ꞌ,4ꞌ-dimethoxyindolyl-3ꞌ-acetonitrile is the first dimethoxy substituted phytoalexin with strong antifungal activity against plant fungal pathogens. The remaining plant species produced known phytoalexins which were initially discovered in wild and cultivated species; all of them produced arvelexin. A novel phytoalexin isocyalexin A, was isolated from rutabaga roots irradiated with UV-light; this is the first isocyanide of plant origin. The second section of the thesis deals with the biosynthesis of metabolites of salt cress (T. salsuginea) and their biosynthetic relationships with indole glucosinolates. In that regard, non-isotopically labeled compounds and perdeuterated biosynthetic intermediates such as [2,2,4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H6]glucobrassicin, [2H3CS;4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H4]-1ꞌ-methoxybrassinin, L-[2ꞌ,4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H5]tryptophan, [2H3CO]-1ꞌ-methoxyindolyl-3ꞌ-acetaldoxime, L-[2H3CS]methionine, [4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H4]brassinin and 1ꞌ-methoxy-2ꞌ-methylbrassinin were administered to salt cress leaves. For the first time, the biosynthetic relationship between indole glucosinolates and cruciferous phytoalexins was established. Intact incorporations of hexadeuterated glucobrassicin ([2,2,4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H6]glucobrassicin) into wasalexins A, B and biswasalexins A1 and A2 were observed. Based on the feeding experiment results, for the first time a biosynthetic route that includes both indole glucosinolates (glucobrassicin and 1ꞌ-methoxyglucobrassicin) and 1ꞌ-methoxybrassinin was proposed. The third section of the thesis is about biosynthesis of metabolites of rutabaga (Brassica napus). Rutabaga produces phytoalexins that differ on their side chains. Biosynthetic origin of their side chains was investigated by administering fully labeled tryptophan (L-[U-13C11,U-15N2]Trp) and other perdeuterated precursors to rutabaga roots which revealed that the carbon and nitrogen atoms of cyclobrassinin, rapalexin A, isocyalexin A and spirobrassinin are fully derived from tryptophan, and also both rapalexin A and isocyalexin A incorporated deuterium from glucobrassicin. [4',5',6',7'-2H4]-4'-Methoxybrassinin was incorporated into 4ꞌ-methoxycyclobrassinin and 4ꞌ-methoxydehydrocyclobrassinin but not into rapalexin A, isocyalexin A and isalexin. The biosynthetic pathway that leads to isalexin, rapalexin A and isocyalexin A was further investigated using perdeuterated biosynthetic precursors such as (R,S)-[2H3CO,5',6',7'-2H3]-4'-methoxyindolyl-3'-glycine, [2H3CO,5',6',7'-2H3]-4'-methoxyindole-3'-carboxaldehyde oxime, [2H3CO,5',6',7'-2H3]desulfoglucorapassicin and etc. It has been confirmed that the pathway involves series of rearrangements that allow transformation of side chain of tryptophan into the side chains of rapalexin A and isocyalexin A without any degradations. In conclusion, cruciferous phytoalexins are derived from glucobrassicin which is a precursor for 1ꞌ- and 4ꞌ-methoxyglucobrassicins. 1-Methoxylated phytoalexins are biosynthesized through 1ꞌ-methoxyglucobrassicin via 1ꞌ-methoxybrassinin. Similarly, 4-methoxy phytoalexins are derived from 4ꞌ-methoxyglucobrassicin through two distinct pathways: via 4ꞌ-methoxybrassinin and 4ꞌ-methoxyindolyl-3ꞌ-glycine.

As espécies selvagens relacionadas ao tomateiro desenvolveram-se em uma ampla gama de latitudes que compreende o sul do Equador ao norte do Chile, ocupando diferentes habitats e constituindo uma fonte de diversidade genética natural. Essa diversidade tem sido utilizada no melhoramento de tomateiro, sobretudo para introgressão de genes de resistência a patógenos e mais recentemente de genes afetando a qualidade dos frutos. Embora a variação genética natural tenha a relevância de algo que foi selecionado na natureza e que pode ter implicações evolutivas, ela ainda é pouco explorada em estudos básicos. Para o uso intensivo desse recurso é necessário lançar mão de cruzamentos e retrocruzamentos em larga escala entre as espécies selvagens e o tomateiro cultivado (Solanum lycopersicum). Para tanto, dispomos de uma cultivar miniatura de tomateiro, a cv Micro-Tom (MT), a qual pode crescer nas mesmas condições requeridas para a planta modelo Arabidopsis thaliana. Com o uso da cv MT, podemos explorar de forma adequada a variação genética natural das espécies selvagens de tomateiro, sendo que a identificação de alterações fenotípicas é muito mais evidente quando podemos visualizar a planta como um todo. Dessa forma, vários alelos ainda não conhecidos foram resgatados dessas espécies, os quais levam a fenótipos distintos daqueles encontrados nos parentais, tais como frutos cor rosa-salmão vindo de S. neorickii, frutos de superfície opaca vindo de S. chmielewskii e frutos de coloração verde escuro vindo de S. galapagense. Esse modelo parece ser de especial importância para isolar genes de efeito maior. Assim, isolamos um locus vindo de S. pimpinellifolium que aumenta o número de flores por inflorescência da cv MT de 7 para 11. Sendo o tomateiro uma planta cultivada, os alelos oriundos das espécies selvagens, além de úteis para estudos genéticos e fisiológicos, podem ser aproveitados em programas de pré-melhoramento. / Tomato wild species evolved in a wide range of latitudes, from the south of Ecuador to the north of Chile, which comprise different habitats and are a source of natural genetic variation. This diversity is commonly used in tomato breeding, especially for the introgression of genes for resistance to pathogens and, recently, for fruit quality. Although natural genetic variation usually has an adaptive significance, which means that it may have evolutionary implications, it is still poorly explored in basic research. For the intensive utilization of this resource, it is necessary to perform large scale crosses and backcrosses between wild species and cultivated tomato. Aiming to this purpose, we used the miniature tomato cultivar, cv Micro-Tom (MT), which can growth in the same minimum requirements of the Arabidopsis thaliana model. Using MT one can adequately explore the natural genetic variation of wild species with less time and space requirements. In addiction, phenotypical alterations are more evident in MT, since one can easily visualize the whole plant. Thus, alleles hitherto unknown were isolated from tomato wild related species, leading to distinct phenotypes, such as pink-salmon fruits from S. neorickii, opaque fruit surface from S. chmielewskii and dark green fruits from S. galapagense. The MT model seems to be particularly adequate for the isolation of major genes and QTLs of great effects. Thereby, we had isolated a S. pimpinellifolium locus that increases the number of flowers per inflorescence, from 7 to 11, in MT. Being the tomato a cultivated plant, the alleles obtained in the wild species, besides to be useful for genetic and physiological studies, can be used in pre-breeding programs.

Submitted by Bruna Rodrigues (bruna92rodrigues@yahoo.com.br) on 2016-09-15T20:16:51Z No. of bitstreams: 1 DissAFP.pdf: 3433362 bytes, checksum: 873b79f0c665e16e5c7c85ca69f042dd (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:58:31Z (GMT) No. of bitstreams: 1 DissAFP.pdf: 3433362 bytes, checksum: 873b79f0c665e16e5c7c85ca69f042dd (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:58:37Z (GMT) No. of bitstreams: 1 DissAFP.pdf: 3433362 bytes, checksum: 873b79f0c665e16e5c7c85ca69f042dd (MD5) / Made available in DSpace on 2016-09-16T19:58:43Z (GMT). No. of bitstreams: 1 DissAFP.pdf: 3433362 bytes, checksum: 873b79f0c665e16e5c7c85ca69f042dd (MD5) Previous issue date: 2015-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The peanut (Arachis hypogaea) is, worldwide, an important source of protein and oil. Pests and foliar diseases are among the factors that limit the economically sustainable production of peanuts in Brazil. Among the pests, thrips and the rednecked peanutworm are considered important pests in São Paulo State. To decrease the cost of production on the management of these pests, genetic improvement to obtain resistant varieties from wild plants is a viable alternative. The main obstacle in the genetic improvement is that the vast majority of wild species of Arachis is diploid, while the cultivated species is allotetraploid. For the barrier of ploidy between the wild and the cultivated peanut to be broken, it is necessary to obtain interspecific hybrids genome AB. Such hybrids should be treated with colchicine to induce polyploidy and get fertile hybrids with two distinct complete genomes (amphidiploid), which can be crossed with A. hypogaea to get the same or similar genomic constitution of the cultivated species. The aim of the research were to identify hybrids derived from crosses made between wild species with A, B or K genome that are resistant to thrips and the rednecked peanutworm and hybrids from one amphidiploid and A. hypogaea, characterize the hybrids and their parents 1) by microsatellite molecular markers, 2) by pollen viability and 3) by their morphology. The molecular markers were genotyped in polyacrylamide gel with standard 10 base pairs. The viability of pollen grains was used to analyze the data of analysis of variance and mean Tukey test, and morphological data were analyzed by Principal Component Analysis. Six polymorphic microsatellite loci were analyzed in 25 F1 plants, 18 of them result of selfing and six of hybridization with a total of three different hybrid combinations plus four hybrid plants from across between the amphidiploid An 13 and A. hypogaea. The pollen viability data corroborated the molecular analysis in the identification of hybrids, noting that An 13 had high viability of pollen grains and interspecific hybrids had low values when compared to their parents and selfed individuals of progeny. From the 63 morphological descriptors measured the ones from the main axis expressed the most morphological variation observed. Pollen viability of F1 hybrid plants obtained by cross among A. hypogaea and the amphidiploid An 13 was above 76%, showing the possibility of new interesting genes introgression in A. hypogaea / O amendoim (Arachis hypogaea) representa, ao nível mundial, uma importante fonte de proteína e óleo. As pragas e doenças da parte aérea estão entre os fatores que mais limitam a produção economicamente sustentável do amendoim no Brasil. Dentre as pragas, o tripes e a lagarta-do-pescoço-vermelho são consideradas as pragas-chave no Estado de São Paulo. Para diminuir o custo da produção diante ao manejo destas pragas, o melhoramento genético para a obtenção de plantas resistentes a partir de plantas silvestres é uma alternativa viável. O principal entrave no melhoramento genético é que a grande maioria das espécies silvestres de Arachis é diplóide, enquanto que a espécie cultivada é alotetraploide. Para que a barreira da ploidia entre o amendoim silvestre e o cultivado possa ser quebrada, é necessária a obtenção de híbridos interespecíficos de genoma AB. Tais híbridos devem ser tratados com colchicina, no intuito de induzir a poliploidização e obter híbridos férteis com dois genomas completos distintos (anfidiplóide), que poderão ser cruzados com A. hypogaea por terem a mesma ou similar constituição genômica da espécie cultivada. Os objetivos do trabalho foram identificar híbridos oriundos de cruzamentos realizados entre espécies silvestres resistentes a tripes e a lagarta-do-pescoço-vermelho de genoma A, B ou K, identificar híbridos entre um anfidiplóide e A. hypogaea e caracterizar os híbridos e seus genitores 1) via marcadores moleculares tipo microssatélites, 2) quanto à viabilidade de grãos de pólen e 3) quanto a sua morfologia. Os marcadores moleculares foram genotipados em gel de poliacrilamida com padrão de 10 pares de base, para analisar os dados da viabilidade de grãos de pólen foi utilizada análise de variância e teste de médias Tukey e os dados da caracterização morfológica foram analisados via análise de componentes principais. Foram analisados seis locos microssatélites polimórficos, em vinte cinco plantas F1, sendo quatorze delas resultado de autofecundação e onze de hibridação, totalizando três combinações híbridas distintas diplóides mais quatro plantas híbridas entre A. hypogaea e o anfidiplóide An 13. Os dados de viabilidade de pólen corroboraram a análise molecular na identificação dos híbridos, observando-se que o An 13 possuía alta viabilidade de grãos de pólen e os híbridos interespecíficos possuíam valores muito abaixo dos genitores e dos indivíduos autofecundados da progênie. Quanto às analises morfológicas, dos 63 descritores mensurados, os descritores do eixo central foram os que mais expressaram a variação morfológica observada. A viabilidade de grãos de pólen das plantas híbridas F1 entre A. hypogaea e o anfidiplóide An 13 foi acima de 76%, mostrando a possibilidade de introgressão de novos genes de interesse em A. hypogaea.

As espécies selvagens relacionadas ao tomateiro desenvolveram-se em uma ampla gama de latitudes que compreende o sul do Equador ao norte do Chile, ocupando diferentes habitats e constituindo uma fonte de diversidade genética natural. Essa diversidade tem sido utilizada no melhoramento de tomateiro, sobretudo para introgressão de genes de resistência a patógenos e mais recentemente de genes afetando a qualidade dos frutos. Embora a variação genética natural tenha a relevância de algo que foi selecionado na natureza e que pode ter implicações evolutivas, ela ainda é pouco explorada em estudos básicos. Para o uso intensivo desse recurso é necessário lançar mão de cruzamentos e retrocruzamentos em larga escala entre as espécies selvagens e o tomateiro cultivado (Solanum lycopersicum). Para tanto, dispomos de uma cultivar miniatura de tomateiro, a cv Micro-Tom (MT), a qual pode crescer nas mesmas condições requeridas para a planta modelo Arabidopsis thaliana. Com o uso da cv MT, podemos explorar de forma adequada a variação genética natural das espécies selvagens de tomateiro, sendo que a identificação de alterações fenotípicas é muito mais evidente quando podemos visualizar a planta como um todo. Dessa forma, vários alelos ainda não conhecidos foram resgatados dessas espécies, os quais levam a fenótipos distintos daqueles encontrados nos parentais, tais como frutos cor rosa-salmão vindo de S. neorickii, frutos de superfície opaca vindo de S. chmielewskii e frutos de coloração verde escuro vindo de S. galapagense. Esse modelo parece ser de especial importância para isolar genes de efeito maior. Assim, isolamos um locus vindo de S. pimpinellifolium que aumenta o número de flores por inflorescência da cv MT de 7 para 11. Sendo o tomateiro uma planta cultivada, os alelos oriundos das espécies selvagens, além de úteis para estudos genéticos e fisiológicos, podem ser aproveitados em programas de pré-melhoramento. / Tomato wild species evolved in a wide range of latitudes, from the south of Ecuador to the north of Chile, which comprise different habitats and are a source of natural genetic variation. This diversity is commonly used in tomato breeding, especially for the introgression of genes for resistance to pathogens and, recently, for fruit quality. Although natural genetic variation usually has an adaptive significance, which means that it may have evolutionary implications, it is still poorly explored in basic research. For the intensive utilization of this resource, it is necessary to perform large scale crosses and backcrosses between wild species and cultivated tomato. Aiming to this purpose, we used the miniature tomato cultivar, cv Micro-Tom (MT), which can growth in the same minimum requirements of the Arabidopsis thaliana model. Using MT one can adequately explore the natural genetic variation of wild species with less time and space requirements. In addiction, phenotypical alterations are more evident in MT, since one can easily visualize the whole plant. Thus, alleles hitherto unknown were isolated from tomato wild related species, leading to distinct phenotypes, such as pink-salmon fruits from S. neorickii, opaque fruit surface from S. chmielewskii and dark green fruits from S. galapagense. The MT model seems to be particularly adequate for the isolation of major genes and QTLs of great effects. Thereby, we had isolated a S. pimpinellifolium locus that increases the number of flowers per inflorescence, from 7 to 11, in MT. Being the tomato a cultivated plant, the alleles obtained in the wild species, besides to be useful for genetic and physiological studies, can be used in pre-breeding programs.

Le genre Chenopodium comprend environ 150 espèces réparties sur l'ensemble du globe et établies dans une large gamme de milieux. En Amérique du Sud, différentes espèces, cultivées comme C. quinoa Willd. et C. pallidicaule Aellen, ou sauvages comme C. hircinum Schrader, sont distribuées sur des gradients pédoclimatiques allant du niveau de la mer au Chili, jusqu'à plus de 4000 m d'altitude sur l'altiplano boliviano-péruvien, sur des sols plus ou moins profonds et riches en nutriments, et sous des climats allant du tropical humide jusqu'au froid aride. Ces espèces sont phylogénétiquement apparentées, et on admet généralement que C. quinoa a été domestiqué à partir de C. hircinum et qu'une partie de son génome proviendrait de C. pallidicaule. Leur large distribution dans des écosystèmes naturels ou agricoles et leur plus ou moins grande tolérance aux contraintes du milieu, font de ce groupe d'espèces un modèle intéressant pour examiner la diversité des réponses des plantes, notamment face à la faible disponibilité en eau dans le sol. La totalité de l'eau nécessaire à la vie de ces plantes passant par le système racinaire, nous nous sommes intéressés aux variations intra- et interspécifiques de l'architecture et de la croissance des racines et à leurs réponses au déficit hydrique, en faisant l'hypothèse que les plantes provenant d'un milieu aride ou d'un système de culture à faible usage d'intrants, ont développé des traits racinaires qui leurs permettent d'accroître l'acquisition des ressources du sol. Pour tester cette hypothèse nous avons comparé la croissance et le développement racinaire de plantes de deux écotypes de C. quinoa de régions plus ou moins arides, et de populations de C. pallidicaule et de C. hircinum, placées dans des conditions de culture contrôlées non limitantes ou déficitaires en eau, en pots et en rhizotrons. Les principaux résultats de ce travail de thèse montrent que, malgré de grandes différences dans la production de biomasse et la morphologie aérienne, les populations étudiées présentent toutes la même typologie racinaire. Elles diffèrent entre elles par plusieurs traits d'architecture et de morphologie racinaire qui déterminent la capacité d'exploration et d'exploitation des ressources du sol. Certains de ces traits, comme la vitesse d'élongation de la racine principale, présentent une grande plasticité de réponse au déficit hydrique. D'autres traits, comme la longueur spécifique des racines, sont moins plastiques mais présentent des différences interspécifiques importantes. Ces variations de l'architecture des plantes forment des syndromes adaptatifs favorisant la survie des plantes dans les milieux les plus contraignants. Mots clés : Chenopodium quinoa, Chenopodium hircinum, Chenopodium pallidicaule, système racinaire, architecture racinaire, topologie racinaire, ontogénie, rhizotron, élongation racinaire, analyses de croissance, espèces cultivées, espèces sauvages, croissance racinaire, morphologie racinaire. / The genus Chenopodium comprises about 150 species distributed all around the world and over a wide range of environments. In South America, differents species, either cultivated as C. quinoa Willd. and C. pallidicaule Aellen, or wild as C. hircinum Schrader, are distributed over pedoclimatic gradients from the sea level in Chile, up to an altitude of 4000 m in the altiplano of Bolivia and Peru, on soils more or less thick and rich in nutrients, and under climates from tropical humid to arid and cold. These species are phylogenetically related, and it is generally admitted that C. quinoa was domesticated from C. hircinum and that part of its genome comes from C. pallidicaule. Their wide distribution in natural and crop ecosystems and their more or less strong tolerance to environmental constraints, make this group of species an interesting model for examining the diversity of responses of the plants, in particular facing a low disponibility of resources in the soil. As all the water necessary for the life of the pass through the root system, we focused our interest in the intra- and interspecific variations in the root growth and architecture, and their responses to the water deficit, with the hypothesis that plants from arid habitats or from low-input agrosystems, developed root traits that allowed them to increase the acquisition of resources in the soil. To test this hypothesis we compared the root growth and development in plants of two ecotypes of C. quinoa from more or less arid regions, and of populations of C. pallidicaule and C. hircinum, placed under non-limiting or water deficit growth conditions, in pots and in rhizotrons. The main results of this research show that, despite large differences in biomass production and morphology of the aerial plant part, the studied populations showed the same root typology. They differed by several traits of root architecture and morphology which control the capacity of the plant to explore and exploit the soil resources. Some of these traits, such as the taproot elongation rate, showed a high plasticity in response to the water deficit. Other traits, like the specific root length, were less plastic but showed large interspecific differences. These variations in plant root architecture conforms adaptive syndromes that favor the plant survival in the most limiting environments. Key words : Chenopodium quinoa, Chenopodium hircinum, Chenopodium pallidicaule, root system, root architecture, topological index, ontogeny, rhizotron, root elongation, plant growth analysis, cultivated species, wild species, root growth, root morphology.

O amendoim (Arachis hypogaea) é a quarta oleaginosa mais consumida no mundo. O Brasil produziu, em 2002, aproximadamente 190 mil toneladas, sendo que 80% da área plantada situa-se no Estado de São Paulo. O principal problema da cultura neste Estado e no mundo são as doenças fúngicas de parte aérea. Diversas espécies do gênero Arachis são consideradas resistentes a várias pragas e doenças. Os objetivos dessa pesquisa foram: 1) identificar espécies silvestres pertencentes à Secção Arachis resistentes à mancha castanha (Cercospora arachidicola), mancha preta (Cercosporidium personatum) e ferrugem (Puccinia arachidis); 2) realizar cruzamentos entre espécies de genoma “A” e “B” resistentes a, pelo menos, uma doença fúngica; 3) duplicar os cromossomos dos híbridos estéreis; 4) realizar cruzamentos entre A. hypogaea e os anfidiplóides sintéticos; 5) obter a geração F1 que tivesse 50% do genoma do amendoim cultivado, 50% do genoma das espécies silvestres. Os experimentos foram conduzidos, em condições de telado, no Departamento de Genética da Escola Superior de Agricultura “Luiz de Queiroz”. Para a identificação de genótipos resistentes às doenças fúngicas, utilizou-se a técnica de folhas destacadas, em laboratório, com inoculação artificial, condições controladas de temperatura a 25°C e luz alternada (10h luz). Os cruzamentos entre espécies silvestres, de genoma “B” com as de genoma “A”, resistentes a pelo menos uma doença foram realizados em condições de telado, com emasculação realizada ao final da tarde e polinização na manhã do dia seguinte. A duplicação de cromossomos de células somáticas de híbridos com genoma “AB”, foi obtida mediante o tratamento de estacas com colchicina a 0,2%, por aproximadamente 12h, em condições de luz e com temperatura entre 25-30°C. Os cruzamentos entre A. hypogaea e os anfidiplóides sintéticos foram realizados em condições de telado, na Embrapa Recursos Genéticos e Biotecnologia. Observou-se que várias espécies silvestres foram altamente resistentes a, pelo menos, uma das três doenças estudadas. Foi possível selecionar, como genitores masculinos, 12 acessos de genoma “A” e, como femininos, seis acessos de genoma “B”. A partir de 26 cruzamentos distintos (3633 hibridações), foi possível obter 17 híbridos interespecíficos distintos com genoma “AB”. Após o tratamento com colchicina de todos os 17 tipos de híbridos, foram obtidas cinco combinações híbridas que produziram flores tetraplóides (A. hoehnei x A. helodes, A. ipaënsis x A. duranensis, A. hoehnei x A. cardenasii, A. aff. magna x A. villosa, A. aff. magna x A. aff. diogoi). Foram realizados 21 cruzamentos entre A. hypogaea e os anfidiplóides sintéticos. Foram obtidos 13 tipos de híbridos: A. hypogaea (cvs. IAC-Tatu-ST, Br-1, IAC-Caiapó, IAC-Runner) x [A. hoehnei x A. cardenasii]; A. hypogaea cv. Br-1 x [A. aff. magna x A. villosa] ; A. hypogaea (acessos V 12548, V 12549, Mdi 1560, Mdi 1538, cvs. BR-1, IAC-Tatu-ST, IAC-Caiapó, IAC-Runner) x [A. ipaënsis x A. duranensis]. Os resultados obtidos confirmam que é possível a introgressão de genes de resistência a partir de espécies silvestres no amendoim cultivado, via cruzamentos, expandindo-se a lista de espécies silvestres utilizadas e ampliando a variabilidade genética liberada para seleção nos programas de melhoramento de amendoim. / Groundnut (Arachis hypogaea) is one of the most important oil species in the world. In 2002, Brazil produced about 190 thousand tonelades, with 80 per cent of cultivated area concentrated in the State of São Paulo. The main problem in crop management in this State and in many other growing areas in the world is represented by fungal diseases. Several species of the genus Arachis are considered resistant to main pests and diseases. This research was developed to take advantage of the genetic variability present in the Arachis genus, and has the following objectives: 1) to identify accessions of wild species belonging to Section Arachis that are resistant to early leaf spot (Cercospora arachidicola), late leaf spot (Cercosporidium personatum) and rust (Puccinia arachidis); 2) to cross resistant species having B and A genomes; 3) to duplicate chromosomes of sterile hybrids; 4) to cross A. hypogaea with synthetic amphiploids; 5) to obtain an F1 generation with 50% of the cultivated groundnut genome and 50% of wild species genomes. Experiments were developed under greenhouse conditions, in the Department of Genetics, faculty of Agriculture "Luiz of Queiroz". Detached leaves technique was used, in laboratory conditions, with artificial inoculation, controlled temperature of 25°C and alternate light (10h light) for the identification of genotypes resistant to fungal diseases. Crosses among wild resistant species with B and A genome genotypes were carried out in greenhouse conditions. Emasculation were hand-made at the end of the afternoon and pollination was made in the following morning. Chromosome duplication of somatic cells in AB genome interspecific hybrids was obtained by treating cuttings with 0.2% colchicine for approximately 12h, in daylight conditions, maintaining the temperature in range of 25-30°C. Crosses between A. hypogaea and synthetic amphyploids were done in greenhouse conditions, at Embrapa Genetic Resources and Biotechnology. It was observed that several wild species were highly resistant to one or more of the studied diseases. Selection of 12 A genome accessions for use as male parents was possible as well as six B genome species as female parents. From 26 different combinations, it was possible to obtain 17 interspecific AB genome hybrids. After colchicine treatment of all 17 hybrid types, five hybrid combinations that produced tetraploid flowers were obtained (A. hoehnei x A. helodes, A. ipaënsis x A. duranensis, A. hoehnei x A. cardenasii, A. aff. magna x A. villosa, A. aff. magna x A. aff. diogoi). Twenty-one different crosses were done between A. hypogaea and synthetic amphyploids. Thirteen different hybrid types were obtained: A. hypogaea (cvs. IAC-Tatu-ST, Br-1, IAC-Caiapó, IAC-Runner) x [A. hoehnei x A. cardenasii]; A. hypogaea cv. BR-1 x [A. aff. magna x A. villosa]; A. hypogaea (accessions V 12548, V 12549, Mdi 1560, Mdi 1538, cvs. Br-1, IAC-Tatu-ST, IACCaiapó, IAC-Runner) x [A. ipaënsis x A. duranensis]. Results confirmed the possibility of introgression of resistance genes from wild species into cultivated groundnut, by manual crosses, increasing the number of wild species used, and thus to enhance the genetic variability released for applying selection in breeding groundnut programs.

O amendoim (Arachis hypogaea) é a quarta oleaginosa mais consumida no mundo. O Brasil produziu, em 2002, aproximadamente 190 mil toneladas, sendo que 80% da área plantada situa-se no Estado de São Paulo. O principal problema da cultura neste Estado e no mundo são as doenças fúngicas de parte aérea. Diversas espécies do gênero Arachis são consideradas resistentes a várias pragas e doenças. Os objetivos dessa pesquisa foram: 1) identificar espécies silvestres pertencentes à Secção Arachis resistentes à mancha castanha (Cercospora arachidicola), mancha preta (Cercosporidium personatum) e ferrugem (Puccinia arachidis); 2) realizar cruzamentos entre espécies de genoma "A" e "B" resistentes a, pelo menos, uma doença fúngica; 3) duplicar os cromossomos dos híbridos estéreis; 4) realizar cruzamentos entre A. hypogaea e os anfidiplóides sintéticos; 5) obter a geração F1 que tivesse 50% do genoma do amendoim cultivado, 50% do genoma das espécies silvestres. Os experimentos foram conduzidos, em condições de telado, no Departamento de Genética da Escola Superior de Agricultura "Luiz de Queiroz". Para a identificação de genótipos resistentes às doenças fúngicas, utilizou-se a técnica de folhas destacadas, em laboratório, com inoculação artificial, condições controladas de temperatura a 25°C e luz alternada (10h luz). Os cruzamentos entre espécies silvestres, de genoma "B" com as de genoma "A", resistentes a pelo menos uma doença foram realizados em condições de telado, com emasculação realizada ao final da tarde e polinização na manhã do dia seguinte. A duplicação de cromossomos de células somáticas de híbridos com genoma "AB", foi obtida mediante o tratamento de estacas com colchicina a 0,2%, por aproximadamente 12h, em condições de luz e com temperatura entre 25-30°C. Os cruzamentos entre A. hypogaea e os anfidiplóides sintéticos foram realizados em condições de telado, na Embrapa Recursos Genéticos e Biotecnologia. Observou-se que várias espécies silvestres foram altamente resistentes a, pelo menos, uma das três doenças estudadas. Foi possível selecionar, como genitores masculinos, 12 acessos de genoma "A" e, como femininos, seis acessos de genoma "B". A partir de 26 cruzamentos distintos (3633 hibridações), foi possível obter 17 híbridos interespecíficos distintos com genoma "AB". Após o tratamento com colchicina de todos os 17 tipos de híbridos, foram obtidas cinco combinações híbridas que produziram flores tetraplóides (A. hoehnei x A. helodes, A. ipaënsis x A. duranensis, A. hoehnei x A. cardenasii, A. aff. magna x A. villosa, A. aff. magna x A. aff. diogoi). Foram realizados 21 cruzamentos entre A. hypogaea e os anfidiplóides sintéticos. Foram obtidos 13 tipos de híbridos: A. hypogaea (cvs. IAC-Tatu-ST, Br-1, IAC-Caiapó, IAC-Runner) x [A. hoehnei x A. cardenasii]; A. hypogaea cv. Br-1 x [A. aff. magna x A. villosa] ; A. hypogaea (acessos V 12548, V 12549, Mdi 1560, Mdi 1538, cvs. BR-1, IAC-Tatu-ST, IAC-Caiapó, IAC-Runner) x [A. ipaënsis x A. duranensis]. Os resultados obtidos confirmam que é possível a introgressão de genes de resistência a partir de espécies silvestres no amendoim cultivado, via cruzamentos, expandindo-se a lista de espécies silvestres utilizadas e ampliando a variabilidade genética liberada para seleção nos programas de melhoramento de amendoim. / Groundnut (Arachis hypogaea) is one of the most important oil species in the world. In 2002, Brazil produced about 190 thousand tonelades, with 80 per cent of cultivated area concentrated in the State of São Paulo. The main problem in crop management in this State and in many other growing areas in the world is represented by fungal diseases. Several species of the genus Arachis are considered resistant to main pests and diseases. This research was developed to take advantage of the genetic variability present in the Arachis genus, and has the following objectives: 1) to identify accessions of wild species belonging to Section Arachis that are resistant to early leaf spot (Cercospora arachidicola), late leaf spot (Cercosporidium personatum) and rust (Puccinia arachidis); 2) to cross resistant species having B and A genomes; 3) to duplicate chromosomes of sterile hybrids; 4) to cross A. hypogaea with synthetic amphiploids; 5) to obtain an F1 generation with 50% of the cultivated groundnut genome and 50% of wild species genomes. Experiments were developed under greenhouse conditions, in the Department of Genetics, faculty of Agriculture "Luiz of Queiroz". Detached leaves technique was used, in laboratory conditions, with artificial inoculation, controlled temperature of 25°C and alternate light (10h light) for the identification of genotypes resistant to fungal diseases. Crosses among wild resistant species with B and A genome genotypes were carried out in greenhouse conditions. Emasculation were hand-made at the end of the afternoon and pollination was made in the following morning. Chromosome duplication of somatic cells in AB genome interspecific hybrids was obtained by treating cuttings with 0.2% colchicine for approximately 12h, in daylight conditions, maintaining the temperature in range of 25-30°C. Crosses between A. hypogaea and synthetic amphyploids were done in greenhouse conditions, at Embrapa Genetic Resources and Biotechnology. It was observed that several wild species were highly resistant to one or more of the studied diseases. Selection of 12 A genome accessions for use as male parents was possible as well as six B genome species as female parents. From 26 different combinations, it was possible to obtain 17 interspecific AB genome hybrids. After colchicine treatment of all 17 hybrid types, five hybrid combinations that produced tetraploid flowers were obtained (A. hoehnei x A. helodes, A. ipaënsis x A. duranensis, A. hoehnei x A. cardenasii, A. aff. magna x A. villosa, A. aff. magna x A. aff. diogoi). Twenty-one different crosses were done between A. hypogaea and synthetic amphyploids. Thirteen different hybrid types were obtained: A. hypogaea (cvs. IAC-Tatu-ST, Br-1, IAC-Caiapó, IAC-Runner) x [A. hoehnei x A. cardenasii]; A. hypogaea cv. BR-1 x [A. aff. magna x A. villosa]; A. hypogaea (accessions V 12548, V 12549, Mdi 1560, Mdi 1538, cvs. Br-1, IAC-Tatu-ST, IACCaiapó, IAC-Runner) x [A. ipaënsis x A. duranensis]. Results confirmed the possibility of introgression of resistance genes from wild species into cultivated groundnut, by manual crosses, increasing the number of wild species used, and thus to enhance the genetic variability released for applying selection in breeding groundnut programs.

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