Batatas (Solanum tuberosum) juntamente com arroz, trigo e milho, são as culturas mais consumida no mundo. A inclusão de novas variedades de S. tuberosum para consumo humano e sob a forma de ração necessita avaliação quanto sua segurança. Normas internacionais citam glicoalcalóides (GA) como tóxicos-chave em avaliação de novas variedades de batatas. Portanto, o objetivo do trabalho foi propor um modelo de avaliação da segurança de novas variedades de batata, incluindo geneticamente modificados, baseado no transcriptoma e análise comparativa de variedades com histórico de segurança. Adicionalmente, pretendeu-se determinar genes referência para análise transcricional de tubérculos. E ainda, caracterizar os genes glycoalkaloid metabolism (GAMEs), que fazem parte da biossíntese de GA e relacionar sua expressão com o total de glicoalcalóides (TGA) em diferentes genótipos de tubérculos de batatas. Para tanto, construiu-se um banco de dados com RNAseq de 90 tubérculos de batatas com grande variabilidade genética e natural. O banco de dados também foi utilizado para ranquear candidatos a genes normalizadores, baseado no intervalo interquartil (IQR), que, posteriormente, tiveram sua estabilidade calculada pelo: geNorm, NormFinder e BestKeeper. O conteúdo de TGA foi medido em cromatografia líquida de alta eficiência com espectrômetro de massa (CLAE-EM) e a expressão dos GAMEs foi determinada por reação de transcriptase reversa quantitativa seguida da reação em cadeia da polimerase (RT-qPCR). Para análise da região promotora utilizou-se: Plant Pan – Plant Promoter Analysis Navigator. Através dos resultados obtidos e analisados, podemos afirmar que o modelo, quando devidamente validado e finalizado, pode ser considerado bastante promissor. Os genes C2, SEC3 e CUL3A foram considerados como excelentes normalizadores para tubérculos de batata. A expressão dos GAMEs foi maior em tubérculos com maior conteúdo de TGA, e com exceção do GAME7, os genes GAME4, GAME6, GAME8ab, GAME11 e GAME12 demonstraram ser estatisticamente (α = 0,05) mais expressos em amostras com maior teor de TGA e menos em amostras com menor TGA, confirmando a relação destes genes com a produção de glicoalcalóides. Na análise de fatores de transcrição dos GAMEs muitos elementos cis relacionados a estresse biótico e abiótico, e regulação por luz foram encontrados, além de muitas cópias desses elementos cis nas regiões promotoras de todos os GAMEs. Os resultados obtidos no presente trabalho são importantes para um melhor entendimento da formação e regulação dos GA em tubérculos de batatas, auxiliando na predição e prevenção de formação deste composto. / Potato (Solanum tuberosum) is the third most important food crop in the world after rice and wheat in terms of human consumption. The introduction of new varieties of S. tuberosum for food or feed requires the checking of not only substances of pro-nutritional functioning on the human body, but should examine the content of toxic compounds, such as glycoalkaloids (GA), as an international norm recommendation for new potatoes varieties evaluation, including genetic modified. For this reason, the goal of the present work was build a food safety assessment model based on transcriptomics, and comparative with history of safe human consumption. Besides, we intended to determined reference genes for transcriptional analysis of potato tuber, and characterized glycoalkaloid metabolism (GAME) genes that partake of GA biosynthesis pathway. The correlation between the expression of GAME genes and total glycoalkaloids (TGA) content in different genotypes of potato tubers was evaluated. To do so, a database was build with RNASeq data from 90 potato tubers with large genotype and natural variability. These database were also used to ranking the candidates to be reference genes based on Interquartile Range (IQR). The stability of candidates for reference genes were evaluated by geNorm, NormFinder and BestKeeper. The content of TGA were measured on high performance liquid chromatography acoplated on mass spectrometry (LC-MS). Later, Reverse Transcriptase quantitative Polymerase Chain Reactions (RT-qPCR) determined the expression of GAME genes. For the promoter region analysis of GAMEs were used “Plant Pan – Plant Promoter Analysis Navigator”. It is possible affirmed that the food safety assessment model after a properly validation will be promising. The best reference genes for transcriptional analysis studies of potato tubers were C2, SEC3 and CUL3A. The expression of GAME4, GAME6, GAME7, GAME8ab, GAME11, and GAME12 were higher in tubers with high TGA content, and, exception for GAME7, the other GAME genes demonstrate statically (α = 0,05) higher expression on samples with high TGA and lower on samples with low TGA content, confirming that there is a relation between GAME genes and GA biosynthesis. On transcription factors analysis of GAME genes several cis-elements related to abiotic and biotic stress, and light regulated were found, also many copies of these factors in all GAME promoter region. All these results are very helpful to better understand GA formation and regulation on potato tubers, helping to predict and prevent the formation of these toxic.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-04-06T13:12:00Z No. of bitstreams: 1 melviscelestevilanculoscossa.pdf: 1078778 bytes, checksum: 97bdef4f96b42adf5a7860d727162f8f (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T03:59:51Z (GMT) No. of bitstreams: 1 melviscelestevilanculoscossa.pdf: 1078778 bytes, checksum: 97bdef4f96b42adf5a7860d727162f8f (MD5) / Made available in DSpace on 2016-04-24T03:59:51Z (GMT). No. of bitstreams: 1 melviscelestevilanculoscossa.pdf: 1078778 bytes, checksum: 97bdef4f96b42adf5a7860d727162f8f (MD5) Previous issue date: 2013-02-27 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / A batata uma essencial “comida para todos”, é hoje uma das mais importantes culturas alimentares e constitui a quarta cultura mais importante do mundo, sendo também fonte de segurança alimentar. Todavia, muitas doenças causadas por vírus, bactérias e fungos afetam a cultura desta planta, resultando em perdas e diminuição da qualidade e segurança dos produtos agrícolas. O controle de doenças nas plantas baseia-se principalmente de pesticidas químicos que estão atualmente sujeitos a fortes restrições e requisitos regulamentares. Nesse sentido, vários peptídeos antimicrobianos têm sido a base para a concepção de novos análogos sintéticos e têm sido expressos em plantas transgênicas para conferir proteção a doenças. O desenvolvimento de plantas transgênicas, contendo um gene que sintetiza um peptídeo antibacteriano, tem sido uma das formas estudadas para se controlar doenças bacterianas. No presente estudo, plantas de batata (Solanum tuberosum), cultivar Asterix, foram transformadas com genes codificadores do peptídeo Pg-AMP1 de Psidium guajava, com objetivo de promover resistência a bactérias que afetam a cultura da batata, nomeadamente Pectobacterium atrosepticum e Pectobacterium carotovorum. Experimentos de transformação genética mediada por Agrobacterium permitiram a obtenção de 13 linhagens transgênicas de Solanum tuberosum Pg-AMP1, representando eventos independentes de transformação. Paralelamente aos experimentos de transformação genética, foram realizados bioensaios in vitro com o peptídeo recombinante purificado Pg-AMP1 contra as cepas bacterianas P. atrosepticum e P. carotovorum e bioensaio in vivo em folhas de plantas de tabaco (Nicotiana tabacum) transformada com o peptídeo com as mesmas cepas bacterianas. No que se refere à resistência das folhas contra o ataque das bactérias P. atrosepticum e P. carotovorum, as linhagens transformadas de tabaco Pg-AMP1 apresentaram sintomas de necrose menos severos comparativamente as não transgênicas. Do mesmo modo o peptídeo Pg-AMP1 apresentou atividade bactericida contra as cepas bacterianas P. atrosepticum e P. carotovorum. Assim sendo, estes resultados sugerem a viabilidade do peptídeo Pg-AMP1 na utilização de transformações genéticas de Solanum tuberosum visando resistência a bactérias patogênicas que afetam a cultura. / Potato, known as essential "food for all", is one of the most important food crops in nowadays. It is the fourth most important crop in the world and is also a source for food security. However, many diseases caused by viruses, bacteria and fungi affect plant cultivation, resulting in losses and decrease the quality and safety of agricultural products. The control of plant diseases is mainly based on chemical pesticides that are currently subject to severe restrictions and regulatory requirements. Accordingly, various antimicrobial peptides have being the basis for new synthetic analogs designing and have been expressed in transgenic plants to confer disease protection. The development of transgenic plants containing a gene that synthesizes an antibacterial peptide, has been has been used to bacterial diseases control. In this study, potato plants (Solanum tuberosum) Asterix, were transformed with genes encoding the peptide Pg-AMP1 from Psidium guajava aiming to produce resistant plants to Pectobacterium atrosepticum and Pectobacterium carotovorum. Experiments of genetic transformation by Agrobacterium - mediated allowed 13 different events of transgenic Solanum tuberosum Pg-AMP1, representing different transformation events. In parallel to genetic transformation experiments in vitro bioassay with recombinant peptide purified Pg-AMP1 was performed. Bacterial strains P. atrosepticum and P. carotovorum were evaluated and in vivo in Tobacco (Nicotiana tabacum) leaves from transformed plants containing the peptide. In resistance assay against P. atrosepticum and P. carotovorum in tobacco plants showed less severe symptoms compared to non-transgenic. Likewise the Pg- AMP1 peptide showed bactericidal activity against bacterial strains P. atrosepticum and P. carotovorum. Thus, these results suggest the feasibility of the peptide Pg- AMP1 the use of genetic transformation of Solanum tuberosum for resistance to pathogenic bacteria that affect the crop.

Made available in DSpace on 2014-06-12T23:14:48Z (GMT). No. of bitstreams: 2 arquivo8684_1.pdf: 514323 bytes, checksum: d4cfce8aa464e24d243be276092dc11f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo geral desse trabalho foi estudar a relação da adubação orgânica e inorgânica de batatinha em solos arenosos, com a produtividade, nutrição da planta e dinâmica da matéria orgânica e nutriente no solo, em áreas cultivadas com batatinha. O estudo foi dividido em três etapas, cada uma com seus objetivos e metodologias específicas. Etapa 1: As relações entre os teores de nutrientes em solos com adubação orgânica e inorgânica e os teores de nutrientes e produtividade de batatinha foram determinadas, assim como, as relações entre aportes e a lixiviação de N e bases trocáveis. Foram coletadas amostras de solo das camadas de 0 20, 20 40 e 40 60 cm em 18 áreas de produção com adições anuais de esterco variando entre 2 e 40 anos e, como controle, quatro áreas sob pastagem não adubadas. Amostras de solo e planta foram analisadas quanto aos teores de N, P, K, Ca e Mg. A produtividade de batatas grandes teve relação positiva com a entrada de N e produtividade total com N total no solo. Somente o Ca no solo correlacionou-se com os teores na planta, mais não com a produtividade. As bases trocáveis tiveram aumento nas três camadas de acordo com o aumento do esterco aplicado, enquanto o N total só teve aumento nas de 0-20 e 20-40 cm. Etapa 2: O objetivo foi determinar a eficiência do sulfato de amônio (15N) mais esterco na adubação da batatinha e do efeito residual no milheto (Pennisetum glaucum) cultivado em seqüência. Em experimento de campo em Neossolo regolítico foi comparada a combinação de 16 t ha-1 esterco + 80 kg ha-1 de N, utilizada mais freqüentemente na região, com doses de 11 t ha-1 de esterco combinadas com 0, 40 e 80 kg ha-1 de N em doses únicas ou parceladas. A fonte de sulfato de amônio utilizado estava enriquecida em 15N (2,5 % de abundância). Em todos os tratamentos avaliou-se a produção de matéria seca nos tubérculos e na parte aérea do milheto alem da composição isotópica do N nesses materiais. A adubação com dose tradicional é excessiva neste solo, uma vez que a redução para 11 t ha-1 esterco e 40 kg ha-1 de N mineral não resultou em queda de produtividade das culturas; no entanto, houve queda no caso de adubação única com esterco. Etapa 3: A mineralização do esterco foi estimada por três métodos: emissão em de C-CO2 em campo, incubação de solo em laboratório e perda de matéria seca em bolsas de rede plástica. O C-CO2 emitido na superfície do solo foi capturado com solução de NaOH, utilizando câmaras acondicionadas na superfície do solo, em parcelas sem e com (11 t ha-1) aplicação de esterco. Em laboratório foi feita a incubação de solo com adição de esterco (11 t ha-1), combinado ou não com sulfato de amônio (60 kg N ha-1), em recipientes de 2000 ml hermeticamente fechados contendo NaOH para captura do CO2, durante 180 dias. As bolsas de decomposição com adição de esterco (11 t ha-1) com e sem sulfato de amônio (60 kg N ha-1), enterradas a 15 cm de profundidade, foram acompanhadas durante 110 dias. A decomposição do esterco, aplicado isoladamente, estimado via emissão de C-CO2 em campo foi inferior a 5%. No ensaio de laboratório a decomposição, estimada pelo acumulado de C-CO2 emitido, foi muito baixa, 5 e 3,5 % para o esterco aplicado isoladamente e com sulfato de amônio, respectivamente, em 180 dias de incubação. A aplicação de esterco combinado com N mineral apresentou menor emissão de C-CO2 comparado com aplicação isolada. As perdas de matéria orgânica do esterco das bolsas plásticas foram de 41 e 51 % nas parcelas sem e com aplicação de N mineral, respectivamente. Acredita-se que a lenta decomposição do esterco foi determinada pela sua alta relação C/N (38) e alto teor de lignina (14 %). A quantidade de esterco habitualmente utilizada pelos produtores é excessiva, o que favorece a translocação de nutrientes para camadas mais profundas, representando prejuízo econômico e possível risco ambiental. Os resultados obtidos nos ensaios de decomposição e de produção de batata indicam que o esterco não é uma fonte imediata de N e sua aplicação deve ser acompanhada de fontes mais ricas nesse nutriente e de liberação mais rápida. O efeito residual do adubo aplicado foi expressivo para a cultura do milheto cultivado em sucessão, pois o mesmo recuperou grande parte do N mineral adicionado à batatinha e mostrou ser uma alternativa como forrageira em condições de semi-árido

Monoploid potato genotypes represent plant material that is free from the "genetic load" of lethal and severely deleterious alleles normally present in the highly heterozygous cultivated potato species. Field evaluations enabled the identification of agronomically superior monoploid potato genotypes from a population of more than 100 anther-derived monoploids. Chemical fusion and electrofusion between pairs selected from 31 superior monoploids resulted in the production of three different groups of intermonoploid somatic hybrids. The hybridity of somatic hybrid plants and calluses was confirmed through PCR-based amplification of simple sequence repeat (SSR) sequences in the potato genome. Polymorphic SSR loci between the monoploid parents of a particular group of somatic hybrids were used to separate true somatic hybrids (heterozygous at the loci) from parental somaclones regenerating from unfused protoplasts (homozygous for one parental band at the loci). One group of somatic hybrids (SH1, SH2 and SH2B) was of particular interest because it resulted from the fusion of a S. phureja monoploid to a high acetylleptinidine-producing monoploid derived from an F1 hybrid between S. chacoense and S. phureja. The leptine acetylleptinidine (ALD) is produced only by some accessions of S. chacoense Bitt. and provides resistance to feeding by the Colorado potato beetle (Leptinotarsa decemlineata Say) when present in sufficient concentrations. The somatic hybrids produced moderate levels of ALD in leaves and stems (roughly 60% that of a high ALD-producing S. chacoense clone). Pollinations of SH1, SH2 and SH2B by several diploid and tetraploid potato clones resulted in three fruit on SH2, one fruit on SH2B and no fruit on SH1. Two resulting progeny populations of SH2 [SH2A = SH2 × S. andigena 8-1 (4x); SH2P = SH2 × S. phureja 66AP11-53 (2x)] expressed higher fertility than the original somatic hybrids and were sexually crossed as both male and female parents to S. tuberosum cv. Atlantic. All of the SH2 progeny populations expressed acetylleptinidines, albeit at lower levels than the SH2 somatic hybrid, providing strong evidence that the genes controlling acetylleptinidine production are dominant. Variation for ALD expression in the SH2 progeny indicated one or a few genes with additive effect controlling the ALD trait. In addition, the choice of male parent in sexual crosses to SH2 affected subsequent ALD expression in progeny populations. The SH2 progeny represent an important first step towards transferring acetylleptinidines to cultivated potato. SH1, SH2 and SH2B appeared to be negatively affected by an unusually high ploidy (hexaploid, 6x). Field-grown plants produced many tubers (mean = 35) of low weight (mean = 10.4 g) and were stunted in appearance. Anther culture of SH2 yielded triploid regenerants (3x). These regenerants may be more phenotypically normal than the original somatic hybrids because of lower ploidy. Segregation of SSR alleles in the triploid anther culture regenerants provided evidence that the hexaploid somatic hybrid SH2 genome is comprised of four homologous genomes of CP2-103 (the high leptine-producing monoploid) and two homologous genomes of 13-14 203 (the S. phureja monoploid). / Master of Science

The potato (Solanum tuberosum L.) crop serves as a staple food worldwide and is capable of reducing the world’s food shortages because unlike cereals and other agricultural crops, it is less affected by prices in the international markets. Research on alleviation of food crises suggested root and tuber crops such as potatoes to be the solution to the problem of food shortage. The crop is widely cultivated but is difficult to produce due to susceptibility to numerous pests and pathogenic organisms, as well as abiotic stresses. To control these pests and diseases, strategies to limit susceptibility to factors that interfere with the growth and development of plants, or breeding new varieties that are able to withstand stresses are being researched. Recent studies have shown that non essential nutrients such as Silicon (Si) are beneficial to plants in terms of yield, protection from fungal diseases and improved uptake of phosphorus. Since very little research has focused on the role of Si in improving potato production, three glasshouse pot trials were conducted at the Hatfield Experimental farm and Department of Plant Pathology glasshouses of the University of Pretoria to evaluate the effect of various soil amendments on potato yield and quality. The effect of these soil amendments on pH was also investigated as P-uptake and development of common scab in potatoes are pH dependent. The soil amendments consisted of different silicon sources and an agricultural lime. The Si sources were Calmasil slag (Middleburg) (30% Si- containing liming material), fly ash (50% Si nonliming material), and Si fume/ash (99% Si non-liming material). Agricultural lime (CaCO3) was included as a control. The purpose of the first two trials was to identify the most promising silicon-containing source for potato production, while the third trial evaluated the effect of this silicon source on soil pH and potato tuber yield. In all three trials, agricultural lime was used as a control. Due to the high demand for nutrients by the potato crop, other nutrient elements were added to the soil through fertigation every 7 to 14 days, depending on the growth stage of the plants. Plants were irrigated with distilled water when necessary to maintain an adequate moisture level i.e. moist but not too wet. Weekly observations on growth parameters were made. To select the most promising soil amendment, parameters such as leaf chlorophyll content, plant height, tuber number and mass (Fwt), fresh and dry weight (top growth) and change in soil pH were analyzed. Slag treated plants tended to produce tubers with higher mass and better appearance. In this study the highest increase in soil pH was observed in soil mixed with slag, compared to all the other silicon sources. Although there was no significant difference observed among treatments there was a distinct difference in plant growth between trials when soil was amended with lime and slag. Plants treated with slag tended to produce tubers that weigh more, whilst plants treated with lime grew taller and had the highest tuber number. There was a significant rise in soil pH from both lime and slag, which might have in turn influenced vegetative and tuber growth. / Dissertation (MInst(Agrar)--University of Pretoria, 2013. / gm2014 / Plant Production and Soil Science / unrestricted

The aim of our diploma thesis was to evaluate the influence of drop irrigation on achieved profit and the quality of chosen consumable variety of potatoes. The field experiment was established on lands of experimental field station AF MENDELU in Žabčice, Brno during a trial period from 2016 to 2017. Two consumable varieties of potatoes with different duration of vegetative period – very early season variety called Monika and mid-early season variety called Jolana – were used for experiments. The influence of additional drop irrigation on profit and strachiness of potatoe tubers was closely monitored. The experiment consisted of four options, always in four repetitions. Particular options were: Control, P60, P65 and P70% of usable water capacity. On the basis of attained results it is possible to note that the drop irrigation is very effective and efficient way to raise profit and quality of potatoes. Due to practical and economic reasons, P60 and P65 appear to be an optimal option of drop irrigation providing medium soil humidity.

Investigations of potato (Solanum tuberosum) have been hampered by its complicated genetics and high genetic load. This dissertation applies genome reduction techniques to investigate a broad swath of genomic and physiological phenomena. It begins with the presentation and evaluation of a protocol to characterize endoreduplication within potato tubers, demonstrating substantial variation between tissue types and among wild species which may facilitate research into the genesis and growth of these starchy underground stems. Next, we transitioned to explore the distribution and consequences of a specific class of transposable element, Miniature Inverted Transposable Elements (MITEs), showing that they comprise approximately 5% of the potato genome, occur more frequently in genes with stress-related functions, and may be associated with changes, especially decreases, in gene expression. We then combined homology and sparsity based approaches to predict recent MITE activity, identifying five families as especially active. Finally, we expose the gene underlying the potato flower color locus, a homolog of AN2, while showing the effects it exerts on the flavonoid biosynthesis and fruit ripening pathways. This region was shown to be particularly dynamic, replete with MITEs and structural variants which we hypothesize to be the ultimate cause of differences in AN2 expression within the germplasm we examined. While the separate topics of this dissertation are quite disparate, each addresses an important topic in potato genetics, the in-depth study of which is only possible through the utilization of genomic reduction approaches to acquire homozygous genotypes for study and currently available genomic resources. / Ph. D. / Despite their humble appearance and routine consumption, potatoes have a complex genetic structure and a life cycle capable of both sexual reproduction through flowers, fruit and seed, and asexual reproduction through the tubers which also comprise the edible product. From an agronomic perspective, one of the most important qualities of a potato tuber is size, a feature influenced by genetics and environment. Cell-to-cell variation for the amount of DNA per cell, one component that influences tuber size, is known to occur, yet our ability to measure DNA content in starchy tuber cells has been obscured by debris generated through routine preparation techniques. We present and evaluate a new method for measuring the DNA content of potato tuber cells, which provides reliable results across a range of different potato varieties and species. ‘Jumping genes’ also known as transposons, first reported in maize but now known to occur in most advanced plant and animal species, have been found to comprise ~5% of the recently sequenced potato genome. We show that a particular class of transposons is more likely to occur adjacent or actually in certain types of genes, such as those which confer resistance to disease, where they may have meaningful effects on how those genes operate. We then proceed to predict the current activity of the various families of these jumping genes to understand how they continue to alter the genetic landscape of potato. Finally we identify a particular gene which dictates flower color in potato (purple vs. white). We demonstrate that several transposons occur in some forms of the flower color gene. Originally we hypothesized that transposons were associated with the turning off of the purple flower color form; however, on closer examination, we could express the white flower form in transgenic plants that were originally white-flowered and convert them to have purple flowers, demonstrating that even the white flower form was functional. While the separate topics of this dissertation are quite disparate, each addresses an important topic in potato genetics, the in-depth study of which is only possible through the availability of the special strains of potatoes with reduced chromosome number and the publication of the potato genome.

Recent advances in plant genetic engineering offer substantial benefits to farmers throughout the world. Genetic research has identified many exogenous genes that could considerably decrease production costs through transgene-mediated resistance to insect, viral, fungal and bacterial pathogens. Potato can be produced from true potato seed (TPS) through a sexual polyploidization step, known as 4x-2x hybridization. Little is known regarding the stability of transgenes through sexual polyploidization in potato, although studies have associated ploidy elevation with transgene silencing in plants such as Arabidopsis thaliana. In the present study, potato was transformed with two different transgenes, cry3Aa and PVYo cp, and transgene expression was analyzed through 4x-2x hybridization. Transgene introgression did not affect fertility or agronomic performance (tuber set, average tuber weight, total tuber yield) of the resulting 4x-2x hybrids; however, reduced seed germination was observed for several transgenic lines in an in vitro study. Ploidy elevation did not affect a highly expressed single copy cry3Aa transgene, simplex or duplex, transmitted through pollen to 4x-2x hybrids. By contrast, multiple copies of cry3Aa triggered significant transgene silencing in diploids and silencing was further pronounced upon pollen transmission to 4x-2x hybrids. Crosses between two, single insert plants demonstrated additional evidence that multiple cry3Aa transgenes resulted in reduced expression, as well as provided evidence for maternal effects on expression of the cry3Aa transgene. Finally, Cry3Aa expression levels of progeny derived from low expressing, multiple copy 4x-2x hybrids indicated that reduction of transgene number in progeny, through meiotic segregation, could increase Cry3Aa expression. The results suggest that 4x-2x hybridization using single copy, male parents can result in high expressing, transgenic 4x-2x hybrids while segregating for a low frequency of non-transgenic hybrids that create a "refuge" to inhibit development of resistance to transgenes in pest populations. / Ph. D.

Le mildiou de la pomme de terre, causé par l'agent pathogène Phytophthora infestans est l'une des maladies les plus préjudiciables de la culture. Jusqu'à présent, la lutte chimique reste le moyen de contrôle le plus utilisé pour la maîtriser, classant la pomme de terre au premier rang en termes d'Indices de Fréquence de Traitement en grande culture. Par ailleurs, l'utilisation de variétés résistantes, comportant notamment des gènes de résistances spécifiques, a également démontré son efficacité pour limiter les dégâts engendrés par cette maladie. Mais leur efficacité est peu durable avec une durée moyenne de 4 ans avant l'apparition du phénomène de contournement par les isolats plus virulents. Il est donc nécessaire de développer des stratégies de contrôle de la maladie en combinant un ensemble d'approches génétiques, culturales, physiques, et chimiques afin de satisfaire au mieux les objectifs agronomiques, environnementaux et socio-économiques. Un modèle, nommé SIPPOM (Simulator for Integrated Pathogen POpulation Management), avait été développé dans le cas de la gestion durable du phoma du colza. Le présent travail a consisté à adapter la structure générique de SIPPOM au cas de la gestion intégrée du mildiou de la pomme de terre en développant des modules spécifiques à partir de modèles préexistants ou développés spécifiquement. Un modèle de culture (Spudgro), un modèle épidémiologique (Guntz-Divoux / Milsol), un modèle de nuisibilité (modèle de Shtienberg) et une fonction de dispersion (modèle de Scherm) ont été identifiés dans la littérature, adaptés et intégrés dans la structure générique de SIPPOM. Cet ensemble de modules a donné lieu à la réalisation du premier prototype opérationnel de la version informatisée de SIPPOM-de-terre sur la plate-forme de modélisation RECORD. Un nouveau modèle, appelé VOLPONE, a été développé pour représenter les dynamiques de repousses de pomme de terre dans une parcelle et sur un tas de déchets. Ce modèle permet de représenter les sources d'inoculum primaire à l'échelle du territoire sous l'influence du climat et des pratiques agricoles. La qualité prédictive du modèle de nuisibilité a été estimée à partir d'un jeu de données expérimentales générées au cours du travail de thèse et s'est montrée correcte. Des exemples de résultats issus de simulations réalisées à l'aide du premier prototype montrent la capacité du modèle, en fonction d'une combinaison de pratiques culturales et de conditions climatiques variables, à prédire la dynamique épidémique de la maladie, ainsi que les dégâts et dommages associés à l'échelle de la parcelle ou sur un parcellaire simple. Néanmoins, d'autres tâches restent à accomplir afin de disposer d'une version achevée de SIPPOM-de-terre sur la plate-forme RECORD. Le travail réalisé illustre la généricité du modèle d'origine SIPPOM et contribue à la production de connaissances et de références permettant l'optimisation d'outils existants tels Mileos®. Les avancées réalisées pourront contribuer à la conception de stratégies de gestion intégrée, collectives et durables pour cette maladie. / Potato late blight caused by the pathogen Phytophthora infestans is one of the most dreaded diseases to this culture. So far, chemical control is the most widespread method used against the pathogen. In turn, the amount of fungicides used to control this disease makes potato the crop with the highest Treatment Frequency Index of all arable crops. The use of resistant varieties, including specific resistance genes, has also demonstrated an effective limitation of injuries that this disease can cause. Still, specific resistances lack durability as there is an average span of 4 years before the emergence of a resistance breakdown phenomenon by more virulent strains. It is therefore necessary to develop control strategies that combine a set of methods (genetic, cultural, physical and chemical) to meet agronomic, environmental and socio-economic criteria. A model named SIPPOM (Simulator for Integrated Pathogen POpulation Management), was developed to address these issues for the control of phoma stem canker on oilseed rape. The present work consisted in adapting the generic structure of SIPPOM for the integrated control of potato late blight by designing specific sub-models using existing models or specifically developed models. A crop model (Spudgro), an epidemiologic model (Guntz-Divoux/Milsol), a damage model (Shtienberg's model) and a dispersal function (Scherm's model) were selected in the literature, adapted, and embedded in SIPPOM's generic structure. This set of sub-models led to an operational prototype of SIPPOM-de-terre under the RECORD modelling platform. A new model, named VOLPONE, was designed to simulate potato volunteer dynamics in a field or on a waste pile. This model permits to simulate inoculum sources at the territory scale under the influence of climate and cropping practices. The predictive quality of the damage model was assessed with data generated in specific field experimentations and proved to be good. Simulation examples produced with the first prototype of SIPPOM-de-terre illustrate the capacity of the model to represent epidemiological dynamics at the field scale or at a small regional scale under the influence of cropping practices and climate. However, further work is required before to totally achieve the design and the implementation of SIPPOM-de-terre under the modelling platform RECORD. The conducted study illustrates the genericity of the model SIPPOM and produced knowledge, references and tools for the integrated management of the disease. The outputs of this work will help design integrated, collective and durable control strategies of potato late blight.

O trabalho teve como objetivo avaliar a resposta à produção total, comercial e por classes de tamanho; ao teor de matéria seca e aos defeitos fisiológicos mancha-chocolate, coração-oco e coração-negro dos tubérculos do clone de batata IAC 2.5, submetido a três doses dos fertilizantes minerais 04-14-08 (N-P2O5-K2O) e sulfato de amônio, complementadas ou não com um composto orgânico de marca comercial Provaso. O experimento foi conduzido de outubro de 2012 a fevereiro de 2013, na Unidade de Pesquisa e Desenvolvimento de Itararé, da Agência Paulista de Tecnologia dos Agronegócios (APTA), em Itararé, SP, nas coordenadas geográficas 24º16\'06\"S e 49º12\'19\"W e altitude de 1200 m. Foi adotado o delineamento em blocos ao acaso em arranjo fatorial 3x2, com quatro repetições. Os tratamentos consistiram em três doses de 04-14-08 no plantio e de sulfato de amônio em cobertura, sendo respectivamente: 2150 kg ha-1 + 200 kg ha-1; 3225 kg ha-1 + 100 kg ha-1; e 4300 kg ha-1 + 0 kg ha-1, com (5000 kg ha-1) ou sem composto orgânico. As doses de 04-14-08 foram calculadas com base na análise de solo e recomendação de 100, 150 e 200% em P2O5 para a cultura da batata, e para a adubação em cobertura, adotou-se respectivamente as doses 40, 20 e 0 kg ha-1 de N e 44, 22 e 0 kg ha-1 de S. A parcela experimental foi composta por quatro fileiras de 3,5 m cada, totalizando 40 plantas. Como parcela útil, foram consideradas as 16 plantas das duas fileiras centrais, excetuando as plantas das extremidades, consideradas bordaduras de cabeceira. O espaçamento foi de 0,35 m entre plantas na fileira e de 0,8 m entre as fileiras. Os dados foram submetidos à análise da variância e as médias foram comparadas pelo teste de Tukey (p < 0,10), utilizando o programa estatístico Sisvar. Nas condições em que o experimento foi conduzido, a alta produtividade comercial de tubérculos (52,4 t ha-1) do clone IAC 2.5 apresentada pelo tratamento com 3225 kg ha-1 de 04-14-08 + 5000 kg ha-1 de composto orgânico no plantio e 100 kg ha-1 de sulfato de amônio em cobertura sugere a importância da complementação da matéria orgânica no aumento da eficiência da adubação mineral. / The study aimed to evaluate the response to total production, marketable production and production by tuber size classes; dry matter content and internal physiological disorders internal brown spot, hollow heart and black heart of potato tubers clone IAC 2.5 subjected to three rates of mineral fertilizers 04-14-08 (N-P2O5- K2O) and ammonium sulphate, supplemented or not with an organic compost trademark Provaso. The trial was conducted from October 2012 to February 2013, at the Research & Development Unity of Agência Paulista de Tecnologia dos Agronegócios (APTA), in Itararé, SP, Brazil (lat. 24º16\'06\'\'S; long. 49º12\'19\'\'W), and altitude of 1200 m. The treatments were arranged in a 3x2 factorial scheme in a completely randomized block design, with four replications. The treatments consisted of three rates of 04-14-08 at planting and ammonium sulphate in dressing fertilization, follow respectively: 2150 kg ha-1 + 200 kg ha-1; 3225 kg ha-1 + 100 kg ha-1; e 4300 kg ha-1 + 0 kg ha-1, with (5000 kg ha-1) or without organic compost. 04-14-08 rates were calculated based on the soil analysis and 100, 150 and 200% on P2O5 recommendation for the potato crop, and for dressing fertilization, was adopted quantities respectively 40, 20 and 0 kg ha-1 of N and 44, 22 and 0 kg ha-1 of S. The experimental plot consisted of four rows of 3.5 m each, for a total of 40 plants. Useful plot was the 16 plants from central rows. The spacing was 0.35 m between plants in the row and 0.8 m between rows. The data were submitted to analysis of variance and treatment means were compared by Tukey test (p < 0,10) using the statistical program Sisvar. Taking in account the conditions in wich the trial was conducted, a high yield of marketable tubers (52.4 t ha-1) for the clone IAC 2.5 by 3225 kg ha-1 of 04-14-08 + 5000 kg ha-1 of organic compost in planting and 100 kg ha-1 of ammonium sulphate in dressing fertilization suggests the importance of organic matter complementing in increasing the efficiency of mineral fertilization.