La succinate déshydrogénase (SDH) est à la fois une enzyme clé du cycle de Krebs oxydant le succinate en fumarate et le complexe II de la chaîne respiratoire mitochondriale impliqué dans le transfert des électrons et la réduction de l’ubiquinone. Des inhibiteurs de cette enzyme (SDHI) ont été développés ou sont en cours de développement comme antifongiques. Cette famille de fongicides est notamment utilisée pour lutter contre Botrytis cinerea, champignon phytopathogène responsable de la pourriture grise sur de nombreuses cultures dont la vigne. Des souches résistantes aux SDHI ont été isolées chez B. cinerea et d’autres champignons phytopathogènes. Chez ces isolats résistants, des mutations ont été identifiées dans les gènes codant la SDH. Au cours de cette thèse, nous avons étudié l’impact de mutations affectant la sous-unité B (SdhB) de la succinate déshydrogénase sur l’activité de l’enzyme, la biologie du champignon B. cinerea et la résistance aux inhibiteurs ciblant cette enzyme. Par mutagénèse dirigée du gène sdhB, nous avons obtenu des mutants dits « isogéniques » qui ont permis de confirmer l’implication de ces mutations dans la résistance aux différentes molécules SDHI. Par ailleurs, nos résultats montrent que les modifications de la sous-unité SdhB affectent l’affinité des SDHI pour la SDH et les niveaux d’inhibition de l’activité SDH par les molécules inhibitrices ; ce qui explique - in fine - les spectres de résistance des mutants aux SDHI. Actuellement, tous les mutants sont résistants au boscalid et les mutants les plus fréquemment retrouvés au vignoble, sdhBH272R/Y, sont sensibles au fluopyram. Les travaux réalisés sur les mutants sdhB montrent que les mutations étudiées ont également un impact sur l’activité de l’enzyme et sur le développement du champignon, conséquences dépendantes du résidu substitué et de la substitution. En particulier, les mutations sdhBH272L/R affectent fortement l’activité de l’enzyme et la fitness du champignon alors que le mutant sdhBH272Y est peu affecté. Enfin, l’analyse de populations de pourriture grise de différentes origines (région, plantes hôtes) par rapport à la résistance aux SDHI réalisée sur les années 2009/2010 montre que les mutants sdhBH272R/Y sont toujours les plus fréquents mais leurs fréquences varient en fonction des situations agronomiques. Notamment la fréquence du mutant sdhBH272R augmente avec la pression de sélection exercée par les fongicides. Ce mutant attire particulièrement notre attention du fait de sa relation non linéaire entre fitness et fréquence au champ. / Succinate dehydrogenase is both a key enzyme of the TCA cycle, oxidizing succinate into fumarate and complex II of the mitochondrial respiratory chain involved in electron transfer and ubiquinone reduction. Inhibitors of this enzyme (SDHIs) have been developed or are in the developmental process as fungicides. Actually, SDHIs are registered to deal with Botrytis cinerea, a phytopathogenic fungus responsible for grey mold on many crops including grapevine. Strains of B. cinerea and other pathogenic fungi have been isolated for their resistance to SDHI. They mainly harbor mutations in genes encoding SDH subunits. During this thesis, we studied the impact of mutations modifying subunit B of succinate dehydrogenase on enzyme activity, fungal biology and resistance to SDHIs. “Isogenic” mutants obtained through site-directed mutagenesis and homologous recombination allowed us to confirm the role of sdhB mutations in SDHIs resistance. Our results also show that the substitutions in the SdhB subunit impact respectively the affinity of SDHIs to SDH and the inhibition levels of SDH activity by inhibitors, which explain – in fine – the resistance spectra observed for the mutants. Up to now, all sdhB mutants are resistant to boscalid and the most frequent mutants observed in grapevines, sdhBH272R/Y, are susceptible to fluopyram. Studies on sdhB mutants reveal that the mutations also impact the enzymatic activity and the fungal development depending on the substitution. In particular, sdhBH272L/R mutations have the strongest impact on enzyme activity and the fitness of the fungus, whereas these parameters are almost not altered in the sdhBH272Y mutant. Finally, grey mold populations from different origins (country, plant host) were analyzed for their SDHI resistance pheno- and genotypes. Yet, the sdhBH272R/Y mutants were the most frequent, but these frequencies varied according to the agronomical situation. Interestingly, the frequencies of the sdhBH272R mutant seem to increase with the selective pressure exerted by fungicides. This mutant is of particular interest because of the absence of correlation between the fitness we measured and the frequencies we observed in natura.

Proteínas e peptídeos ricos em glicina são encontrados em animais e plantas. Alguns apresentam atividade antimicrobiana. Como pouco se sabe sobre suas síntese, estrutura, relação estrutura-atividade e mecanismo de ação, tais tópicos foram estudados para os antimicrobianos cheferina I (Chef I) e/ou fragmentos da acantoscurrina (acanto). No que se refere à Chef I (67,9% de Gly, 28,6% de His, seis repetições do motivo GGH e uma Tyr), sintetizamos, purificamos, caracterizamos e testamos Chef I, os seus análogos truncados na(s) porção(ções) N- ou/e C-terminal (is) e os análogos amidados Chef la, Chef I (3-28)a e Chef I (6-28)a. Os três últimos e Chef I foram igualmente ativos frente a cepas de C. albicans (MIC: 12,5 µM), mas não frente a cepas de C. tropicalis e S. cerevisiae. A amidação tornou o análogo Chef I (3-28)a mais ativo frente a tais cepas. Enquanto as atividades antifúngicas de Chef la e de seus análogos foram reduzidas pelo aumento da força iônica, elas foram aumentadas em presença de ZnCl2 5-10 µM. A 62,5 µM a Chef la foi letal para C. albicans MDM8. Ela foi pouco hemolítica em tampão fosfato contendo NaCl ou em tampão glicose fosfato isotônico (100 µM: 18%). Análises por microscopia confocal e citometria de fluxo revelaram que Chef la marcada com carboxifluoresceína (FAM-Chef la) foi rapidamente internalizada nas células de C. albicans MDM8, um processo que não foi afetado pela força iônica do meio e se mostrou dependente de ATP e temperatura. Quanto aos fragmentos da acanto (proteína com 132 aminoácidos, 73% de Gly e 3 repetições de uma seqüência de 26 aminoácidos), estudamos a síntese em fase sólida dos fragmentos N- e C-terminais, acanto (1-22) e acanto (101-132) , respectivamente, e da porção repetitiva, acanto (23-48). Apesar de uma predição teórica não ter indicado alto potencial de agregação para a acanto, as sínteses foram problemáticas: a ocorrência de aminoacilações incompletas repetitivas a 60° C usando diferentes estratégias, resinas, reagentes acopladores, solventes e sais caotrópicos sugeriram a ocorrência de agregação das cadeias peptídicas em crescimento sobre as resinas O uso da resina CLEAR amida permitiu a obtenção do acanto (113-132). Tentativa de síntese convergente em fase sólida não foi bem sucedida. Espectros Raman das peptidil-resinas obtidas confirmaram a presença de estruturas em folha β pregueada. Somente o uso combinado de resina CLEAR amida, 60°C, 20% DMSO/NMP, Fmoc-(Fmoc-Hmb)Gly-OH e LiCI permitiram a síntese total de acanto (101-132) . O uso da resina CLEAR ácida permitiu a síntese do fragmento acanto (23-48) e acanto (10-22) , esta última durante a tentativa de síntese do acanto (1-22) . Os rendimentos foram baixissimos e os espectros Raman das peptidil-resinas correspondentes também indicaram a formação de folhas β pregueadas. Estes resultados indicaram que Chef I (3-28)a mimetiza Chef I, que Chef la é um fungicida potente com alvo intracelular, que a internalização do seu análogo marcado na célula de levedura ocorra via endocitose, que a Chef la tem potencial para agir como uma droga de uso tópico e que os fragmentos de acanto são \"difficult sequences\" típicas. / Proteins and peptides with high content of glycine have been found in animais and plants. Some of them display antimicrobial activity. As little is known about their chemical synthesis, structure, structure-activity relationship and mode of action, we studied such topics using shepherin I (Shep I) and fragments of acanthoscurrin (acantho) as targets. Concerning to Shep I (67.9% of Gly, 28.6% of His, six direct repeats of the motif GGH and one Tyr), we synthesized, purified, characterized and tested Shep I, its analogues truncated at the N- and/or C-terminal portions and the amidated analogues Shep la, Shep I (3-28)a and Shep I (6-28)a. The last three analogues and Shep I were equally active against C. albicans (MIC: 12.5 µM) strains, but not against C. tropicalis and S. cerevisiae strains. Cterminal amidation made Shef I (3-28)a more active against those fungai strains. Anticandidal activities of Shep la and truncated analogues were inhibited in high ionic strength solutions, but enhanced at 10 µM ZnCI (2 to 8-fold). At 62.5 µM (5 MIC), Shep la killed C. albicans MDM8 in 30 mino It caused low hemolysis in phosphate buffered saline and isotonic glucose phosphate buffer (100 µM: 18%). Confocal microscopy and flow cytometry analyses revealed that Shep I modified with carboxyfluorescein (FAM-Shep la) was rapidly internalized into C. albicans MDM8 cells, process not affected by ionic strength and showed to be energy and temperature-dependent. As to the fragments of acantho (a protein with 132 amino acids, 73% of Gly, and three repeats of 26 amino acids), we studied solid-phase syntheses of the N- and C-terminal portions, acantho (1-22) and acantho (101-132), respectively, and of the repetitive portion, acantho (23-48). A theoretical prediction did not indicate high aggregation potential for acantho, but solid-phase syntheses were troublesome: repetitive incomplete aminoacylations took place even at 60°C using different strategies, resins, coupling reagents, solvents and chaotropic salts, suggesting aggregation of the growing peptide chains. Change to CLEAR amide resin allowed obtaining acantho (113-132) . Attempt using convergent solid phase synthesis was not successful. Raman spectra of the growingpeptidyl-resins revealed pleated β-sheet structures. Only the combination of CLEAR amide resin, 60°C, 20% DMSO/NMP, Fmoc-(Fmoc-Hmb)Gly-OH and LiCl allowed the total synthesis of acantho (101-132). The use of CLEAR acid resin also allowed obtaining the fragments acantho (23-48) and acantho (10-22), the last one during the attempt of the synthesis of acantho (1-22). The synthesis yields were extremely low and, again, the Raman spectra of the growing peptide-resins indicated the occurrence of pleated β-sheet structures. Altogether, the results indicated that Shep l (3-28)a mimics the fungicidal activity of Shep l, Shep la is a potent anticandidacidal peptide that has an intracellular target, FAM Shep la may be internalized into the fungai cells via endocytosis, Shep la has the potential to act as a drug for topical use and acantho fragments are typical difficult sequences.

Le but de notre travail est de développer une stratégie de vectorisation pour conférer la mobilité phloémienne aux produits agrochimiques en appliquant le concept de prodrogue dans l'élaboration de composés phytopharmaceutiques. Le fenpiclonil, fongicide non systémique de la famille des phénylpyrroles, a été choisi comme composé parent modèle et modifié en l'associant à un acide alpha-aminé ou à un monosaccharide.La mobilité phloémienne des conjugués entre le fenpiclonil et les acides L ou D-glutamique ou le D-glucose (D-GFC) a été évaluée chez des plantules de ricin. Le test de systémie a montré que le L-aminoacide était nettement plus favorable à la mobilité phloémienne que l'acide D-aminé ou le D-glucose. Les résultats suggèrent que le conjugué fenpiclonil/L-aminoacide est reconnu et manipulé par un système de transport d'acide aminé stéréospécifique énergisé par la force proton-motrice. Des expériences complémentaires ont montré que le D-GFC était un inhibiteur puissant et sélectif de l'absorption du saccharose par les tissus foliaires et du chargement phloémien du saccharose. En raison de l'inhibition spécifique des transporteurs de saccharose (par exemple AtSUC2), le D-GFC peut être envisagé comme un nouvel outil en phloémologie.Enfin, nous avons exploré l'impact de la modification de structure de l'espaceur afin d'optimiser la stratégie de prodrogue. Après avoir introduit différentes structures d'espaceur entre le fenpiclonil et la fonction acide aminé, le conjugué qui contient un cycle triazole avec l'acide aminé comprenant la chaine la plus courte a montré la meilleure mobilité phloémienne et, par ailleurs, une systémie optimisée par rapport aux dérivés acides du fenpiclonil dans la gamme des valeurs de pH de l'apoplasme foliaire. / The purpose of our work is to develop a vectorization strategy to confer phloem mobility to agrochemicals by applying prodrug concept into agrochemical design. Fenpiclonil, a non-systemic fungicide from the phenylpyrrole family, was selected as a model parent compound and modified by associating it with an amino acid or a monosaccharide.The phloem mobility of L and D-glutamic acid and D-glucose fenpiclonil conjugates (D-GFC) was evaluated in Ricinus seedlings. The systemicity test showed that the L-amino acid promoiety was clearly more favorable to phloem mobility than D-amino acid or D-glucose. The results suggested that the transport of the L-amino acid conjugate is governed by a stereospecific amino acid carrier system energized by the proton motive force. Further investigation indicated that D-GFC was a potent and selective inhibitor of sucrose uptake by leaf tissues and sucrose phloem loading. Due to its specific inhibition of sucrose transporters (e.g. AtSUC2), D-GFC can be a candidate as a new tool in phloemology. Finally, we explored structural modifications of the spacer arm to optimize the prodrug strategy. Different structures of the spacer arm were introduced between fenpiclonil and the amino acid function. The conjugate which contains a triazole ring with the shortest amino acid chain showed the best phloem mobility and a better systemicity than fenpiclonil acidic derivatives within the pH range of the foliar apoplast.

A soja é uma cultura de importância econômica fundamental e o Brasil está entre os principais produtores mundiais. A ferrugem asiática, causada pelo fungo Phakopsora pachyrhizi, é uma doença relativamente recente no Brasil e pode causar grandes perdas na cultura da soja, representadas pela diminuição da produtividade e pelas despesas com aquisição e aplicação de fungicidas. Já existem algumas fontes de genes de resistência vertical para esta doença, mas também já existem casos de quebra de resistência de alguns destes genes principais. A tolerância, definida como a capacidade da planta em suportar o ataque do patógeno sem apresentar perdas significativas, é uma estratégia complementar que pode ser utilizada no controle da ferrugem. O objetivo desta pesquisa foi estudar a tolerância à ferrugem asiática em genótipos experimentais derivados de 45 cruzamentos em dialelo 10 x 10 do Setor de Genética Aplicada às Espécies Autógamas do Departamento de Genética/ESALQ/USP por meio de métodos de estimação do efeito ferrugem e da estabilidade fenotípica em combinações de manejos de fungicidas, locais e anos agrícolas, além de identificar linhagens promissoras para inclusão em futuros programas de melhoramento. Os delineamentos experimentais utilizados foram blocos aumentados de Federer nos anos 2011/12 e 2012/13 e blocos ao acaso estratificados em conjuntos em 2013/14. Em cada ano e local foram realizados dois experimentos: manejo 1, com aplicações de fungicidas para o controle da ferrugem e outras doenças fúngicas, incluindo as doenças de final de ciclo; manejo 2, com apenas o controle de outras doenças fúngicas, excluindo-se a ferrugem. O contraste entre estes dois manejos com fungicidas permitiu uma estimativa da tolerância. Além disso, foram utilizadas as medidas de estabilidade-bmg (Pi) e ecovalência (Wi) para quantificar a tolerância relativa entre genótipos. Foram pesquisadas 225 progênies F2:7 em 2011/12; 675 linhagens F7:8 em 2012/13 e as melhores 225 linhagens F7:9 em 2013/14. Os resultados obtidos permitiram concluir que: a) houve evidências claras de tolerância à ferrugem asiática entre e dentro de cruzamentos; b) a estratégia de utilizar a comparação entre diferentes manejos de fungicidas para estimar a tolerância (efeito ferrugem) foi útil para a seleção, mas sofreu instabilidade, apresentando baixas correlações entre anos agrícolas; c) os métodos da estabilidade baseada no melhor genótipo (bmg) e da ecovalência complementaram as informações obtidas do efeito ferrugem e auxiliaram na seleção de linhagens tolerantes; d) avaliações iniciais da severidade de ferrugem (nota de ferrugem NF1) apresentaram baixa precisão, tornando recomendável concentrar as avaliações da severidade após maior tempo de infecção (NF2 e NF3) para melhor eficácia na estimação da tolerância; e) a tolerância estimada pelo peso de cem sementes mostrou baixa correlação com a tolerância estimada para produtividade de grãos, de maneira que o uso combinado dos dois critérios melhorou a eficiência da seleção para tolerância e produtividade; f) na seleção simulada foram identificadas 48 linhagens promissoras para tolerância à ferrugem e produtividade, correspondente a um porcentual de seleção de cerca de 22%. / Soybean is an economically important culture and Brazil is among the largest world producers. Asian rust, caused by the fungus Phakopsora pachyrhizi, is a relatively new disease in Brazil and can cause large losses in this culture, represented by yield decreases and increases in costs for fungicide applications. There are some sources of vertical resistance genes for this disease, but there are also cases of resistance breakdown for some of these main genes. Tolerance, defined as the capacity of plants to endure a pathogen attack without significant losses, is a complementary strategy that can be used to control rust. The objective of this research was to study tolerance to Asian rust in experimental genotypes derived from 45 crosses in a 10 x 10 diallel design developed at the Sector of Applied Genetics to Self- Pollinated Crops, Department of Genetics/ESALQ/USP through methods of estimation of the rust effect and of phenotypic stability in combinations of fungicide managements, locations and years, besides identifing promising lines for inclusion in future breeding programs. The experimental designs used were Federer\'s augmented blocks in 2011/12 and 2012/13 and a randomized block design stratified in sets in 2013/14. In each year and location two experiments were performed: management 1, with the application of fungicides to control rust and other fungal diseases, including late season leaf diseases; management 2, only controlling other fungal disease, excluding rust. The contrast between these two managements allowed for an estimate of tolerance. Besides that, the stability based on the best genotype (Pi) and ecovalence (Wi) measurements were also used to estimate relative tolerance between genotypes. In 2011/12 225 F2:7 progenies were evaluated; in 2012/13 675 F7:8 lines were evaluated and the best 225 F7:9 lines were evaluated in 2013/14. The results let to the following conclusions: a) there was clear evidence of tolerance to Asian rust among and within crosses; b) the strategy of comparing different fungicide managements to estimate tolerance (rust effect) was useful, but suffered instability, presenting low correlations among years; c) the methods of superiority or stability based on the best genotype (bmg) and ecovalence complemented the information based on the rust effect and aided in the selection of tolerant lines; d) initial evaluations for rust severity (rust score NF1) had low precision and it was recommended to concentrate on rust tolerance evaluations after longer periods of infection (NF2 and NF3); e) tolerance estimated by means of hundred-seed weights had low correlation with tolerance estimated by seed yield, therefore the combined use of both criteria improved the efficiency of selection for tolerance and seed yield; f) in the simulated selection 48 promising lines were identified for rust tolerance and seed yield, corresponding to approximately 22% selection percentage.

Some aspects of the presence of systemic endophytic fungi in agriculturally important New Zealand grasses were studied in relation to plant breeding. Seedling resistance to adult Argentine stem weevil feeding in perennial ryegrass, Italian ryegrass and tall fescue was found to be related to the presence of their respective Acremonium endophytes in the seed rather than to plant genetic resistance. In addition a study of perennial ryegrass revealed that this resistance was independent of endophyte viability. The seedling resistance conferred by the endophyte of Italian ryegrass was found to be beneficial for field establishment. This endophyte differs from that in perennial ryegrass and tall fescue in that it does not confer resistance to Argentine stem weevil on mature plants, but only on seedlings. The extent of plant genetic seedling tolerance to adult Argentine stem weevil feeding was limited to broad inter-specific differences, with tall fescue more tolerant than perennial ryegrass and both of these more tolerant than Italian ryegrass. This ranking corresponds with previous observations on feeding preference on mature plants. A study of factors affecting the concentration of endophyte mycelia in infected seed of perennial ryegrass revealed that plant genetic factors had little effect. The major factors studied were: 1) the endophyte concentration in the maternal parent plant directly influenced the endophyte concentration in the seed. 2) nitrogen fertilizer applications to a seed crop reduced the concentration of mycelia in the seed, with earlier applications having a greater effect. 3) application of the fungicide propiconazole (Tilt) to a seed crop reduced the endophyte concentration in the seed. 4) the endophyte concentration in the seed was found to directly influence the endophyte concentration in seedlings, six month old plants and that of seed harvested from a first year seed crop. As there have been no previous reports of tetraploid perennial ryegrass cultivars with endophyte an experiment was conducted to determine if these could be developed by the standard procedure of colchicine treatment. The results revealed that endophyte was retained following colchicine treatment.

No description available.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The maize is one of the most important cereal grown worldwide. With the advancement of acreage and monoculture, the emergence of several diseases is well known, which has generated losses of quality and productivity of these grains. Among the diseases affecting the corn crop, there is the rot of corn which consequently cause the so-called burning grains, in addition, some of the causative fungi can synthesize mycotoxins that contaminate grain, affecting the quality of these and mainly generating risks animal and human health. In this context the objective of this study is to evaluate the influence of the hybrid, the seeding system, irrigation and foliar application of fungicides in the incidence of fungi that cause the ear rot in corn. The experiments (Experiment I, as irrigation and Experiment II, without irrigation) were installed and conducted in Cruz Alta, RS, in the season 2014/15. The experimental design was randomized blocks in three-factor scheme 2x2x4 corresponding to two hybrids (BG7051H and BG7060HR), two seeding system (direct and conventional) and four treatments (T1: Witness, T2: Pyraclostrobin + Epoxiconazole; T3: Picoxystrobin + cyproconazole; T4: Azoxystrobin + Benzovindiflupir), respectively, in 4 repetitions. The experimental plot had four rows spaced (0.50 m 10.0 m), total area of 20 m2 and floor area of 8 m2, which took place the plant height of reviews and the insertion of the first ear (cm) mass tang (g), number of grains per ear (n), mass of grains per spike (g) of the 1000 seeds (g), grain yield (kg ha-1), incidence of damaged kernels (%) , grain sanity ( "Blotter Test") and in vitro susceptibility of fungi the fungi Penicillium sp., Fusarium spp. and Aspergillus sp. fungicide. / O milho é um dos mais importantes alimentos para humanos e animais, sendo considerado um dos principais cereais cultivados no mundo. Com o avanço das áreas cultivadas e do monocultivo, o surgimento de diversas doenças é notório, o que tem gerado perdas de qualidade e produtividade desses grãos. Dentre as doenças que afetam a cultura do milho, destaca-se a podridão de espiga que por consequência ocasiona os chamados grãos ardidos, além disso, alguns dos fungos causadores podem sintetizar micotoxinas que contaminam os grãos, afetando a qualidade destes e principalmente gerando riscos à saúde animal e humana. Neste contexto o objetivo deste trabalho foi avaliar a influência do híbrido, do sistema de semeadura, da irrigação e da aplicação foliar de fungicidas na incidência de fungos causadores da podridão da espiga na cultura do milho. Os experimentos (Experimento I, como irrigação e Experimento II, sem irrigação), foram instalados e conduzidos no município de Cruz Alta, RS, na safra agrícola 2014/15. O delineamento experimental utilizado foi em blocos casualizados, em esquema trifatorial 2x2x4 correspondente a dois híbridos (BG7051H e BG7060HR), dois sistemas de semeadura (direta e convencional) e quatro tratamentos (T1: Testemunha; T2: Piraclostrobina + Epoxiconazol; T3: Picoxistrobina + Ciproconazole; T4: Azoxistrobina + Benzovindiflupir), respectivamente, em 4 repetições. A parcela experimental apresentou 4 linhas espaçadas (0,50 m e 10,0 m), área total de 20 m2 e área útil de 8 m2, onde realizou-se as avaliações de altura de planta e da inserção da primeira espiga (cm), massa da espiga (g), número de grãos por espiga (nº), massa de grãos por espiga (g), massa de 1000 grãos (g), produtividade de grãos (Kg ha-1), incidência de grãos ardidos (%), sanidade de grãos ( Blotter Test ) e sensibilidade in vitro de fungos dos gêneros Penicillium sp., Fusarium spp. e Aspergillus sp. a fungicidas.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The use of Cu-based fungicides in the cultivation of grapevines for controlling fungal diseases results in excessive accumulation of Cu in soils, which may cause nutritional problems to plants. The present work aimed to investigate the accumulation and forms of Cu in acid sandy soils cultivated with vineyards in the Campanha Gaúcha region and the biochemical and physiological responses of grapevines in productive season. The study was conducted from 2009 to 2011 in the vineyards of the cultivar Cabernet Sauvignon, grown in the Campanha Gaúcha region, municipality of Sant Ana do Livramento, RS. First, the total (CuT) and available (CuEDTA) concentration of Cu were assessed in 19 vineyards at different ages and historic of applications of Cu-based fungicides. In addition, assessments were carried out for the vertical distribution of CuT and CuEDTA, the amount of accumulated CuT per hectare and the forms of Cu in the soil (chemical fractionation) in three vineyards aged 5, 11 and 31 years of cultivation. A soil collected from an area under natural field, near the vineyards, was used for comparison purposes. In the second part of the study, concentration and accumulation of Cu in the organs of the grapevines and the concentrations of macronutrients and biochemical parameters in leaf blades were investigated in vineyards grown in soils with increasing Cu concentrations. Tissue samples were collected from vines in the 2009/2010 and 2010/2011 vegetative cycles, at various phenological stages, before and after the application of Cu-based fungicides. The results reveal that the vineyards aged over 25 years of cultivation presented average concentrations of 90 mg kg-1 of CuT in the surface layer of the soil. Approximately 77% of the total Cu accumulated in the soil is CuEDTA, and thus potentially available to plants. The main form of accumulation of Cu in the soils of the vineyards was related to the mineral fraction (bound to iron and manganese oxides), which represented 75% of CuT, followed by the organic matter that complexes only 20% of the total. No significant changes were observed in the residual fraction of Cu, with higher bond strength, which indicates the prevalence of potentially available forms. In the grapevines, increased Cu concentrations were observed in leaves, as well as evidence of oxidative stress, which were correlated with increased concentrations of Cu in soil. However, the increased availability of Cu in soils slightly affects the concentrations and content of Cu in grapevines in productive season and does not change their nutritional status. The use of Cu-based fungicides is the main determinant of increased concentration of Cu in annual organs of grapevines, especially leaves and rachis, but the residue of Cu in the berries is not related to the amount applied to the element. / No cultivo de videiras, o uso de fungicidas cúpricos para o controle das doenças fúngicas causam o acúmulo excessivo de Cu em solos, o que pode provocar alterações nutricionais às plantas. O trabalho objetivou estudar o acúmulo e formas de Cu em solos arenosos e de carácter ácidos cultivados com vinhedos na região da Campanha Gaúcha do Rio Grande do Sul e as respostas fisiológico-bioquímicas de videiras em produção. O estudo foi realizado nos anos de 2009 a 2011 em vinhedos da cultivar Cabernet Sauvignon cultivados na região da Campanha Gaúcha, município de Sant Ana do Livramento, RS. Primeiramente foram investigados os teores de Cu total (CuT) e disponível (CuEDTA) em 19 vinhedos com diferentes idades e históricos de aplicações de fungicidas a base de Cu. Além disso, também investigouse a distribuição vertical de CuT e CuEDTA, a quantidade de CuT acumulado por hectare e as formas de Cu no solo (fracionamento químico) em três vinhedos com 5, 11 e 31 anos de cultivo. Um solo coletado em uma área sob campo natural, próximo aos vinhedos, foi utilizado para fins de comparação. Na segunda parte do estudo foram avaliados os teores e acúmulo de Cu nos órgão das videiras e teores de macronutrientes e parâmetros bioquímicos em limbos foliares em vinhedos cultivados em solos com teores crescentes de Cu. As amostras de tecidos das videiras foram coletadas nos ciclos vegetativos 2009/2010 e 2010/2011, em vários estádios fenológicos, antes e também após a aplicação de fungicidas a base de Cu. Os resultados mostras que os vinhedos com mais de 25 anos de cultivo apresentaram teores médios de 90 mg kg-1 de CuT na camada superficial do solo. Do total de Cu acumulado nos solos, aproximadamente, 77% é CuEDTA, sendo portanto, potencialmente disponível para as plantas. A principal forma de acúmulo de Cu nos solos dos vinhedos foi ligada à fração mineral (ligados aos óxidos de ferro e manganês), que representou 75% do CuT, seguido pela matéria orgânica que complexa apenas 20% do total. Não foram observadas alterações importantes na fração residual de Cu, de maior força de ligação, o que indica a prevalência de formas potencialmente disponíveis. Nas videiras foram observados incrementos nos teores de Cu nas folhas e evidência de estresse oxidativo que foram correlacionados com o aumento dos teores de Cu no solo. Contudo, o aumento da disponibilidade de Cu nos solos pouco afeta os teores e o acúmulo de Cu em videiras em produção e não altera seu estado nutricional. O uso de fungicidas a base de Cu é o principal fator determinante do aumento dos teores de Cu nos órgãos anuais das videiras, especialmente, nas folhas e ráquis, mas o resíduo de Cu nas bagas não está relacionado à quantidade aplicada do elemento.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Diseases and environment are closely related, especially with regard to air temperature and relative humidity. The weather data tend to follow a daily pattern of temporal variation, which derives mainly from the daily variation of the surface radiation balance. Based on this, this study aimed to make a qualitative and quantitative description of the database of the Automatic Meteorological Station of the Instituto Nacional de Meteorologia (INMET) in Santa Maria, RS, determine the hours of greatest frequency of occurrence of daily extreme air temperatures in Santa Maria, develop models to estimate hourly values of air temperature (T) and relative humidity (RH), based on values measured in "UTC standard times" and on the daily minimum air temperature and to determine the risk of fungal diseases occurrence during the developmental cycle of potato in different planting dates, using the Blitecast forecasting system. Models were fitted to estimate air T and partial vapor pressure of water at different times of the day. RH was indirectly obtained from partial vapor pressure of water and saturation vapor pressure, calculated from estimated T values. The database of Principal Climatological Station of Santa Maria was transformed to an hourly estimated T and RH database and the Blitecast's calculated severity values (CSV) were obtained for 14 planting dates in 43 years. The automatic weather station of Santa Maria, RS, belonging to INMET, shows 90.1% of the days of flawless data records in 10 years, from 2002 to 2011. The minimum daily air temperature in Santa Maria occurs more frequently at 09AM UTC, corresponding to 6AM on local official time, from September to February. From March through August, this time is delayed, and its occurrence to be more frequent at 10 h UTC. The precision of the estimates ranged from 0.7 ºC to 1.5 ºC, with average deviation of 0.65 °C for T and 0.7 % to 1.2 %, with average deviation of up to 4% for RH depending on the time. Potato crops during the Fall growing season require on average 54% more fungicide applications compared to the Spring season. In the Spring growing season the most probable number of sprayings ranged from two to four and from six to seven in the Fall growing season. Potato crops planted in August and March were demanded a lower economic, ecological and farmer health cost in crop protection against late blight than earlier crops (July and February). / Doenças e ambiente estão intimamente relacionados, especialmente no que se refere à temperatura e umidade relativa do ar. Os elementos meteorológicos tendem a seguir um padrão de variação temporal diária, que deriva principalmente da variação diária do balanço de radiação da superfície. Com base nisso, o objetivo desse trabalho foi descrever qualitativa e quantitativamente do banco de dados da Estação Meteorológica Automática do Instituto Nacional de Meteorologia de Santa Maria (INMET), determinar os horários de maior frequência de ocorrência das temperaturas extremas diárias do ar em Santa Maria, desenvolver modelos para estimativa dos valores horários de temperatura (T) e umidade relativa do ar (UR) e determinar o risco de ocorrência de requeima no ciclo de desenvolvimento da batata, em diferentes datas de plantio. Foram ajustados modelos analíticos para estimativa da T e da pressão parcial de vapor no ar nos diferentes horários do dia. A UR foi obtida indiretamente, com base nos valores de pressão parcial de vapor no ar estimados e nos valores de pressão de saturação de vapor no ar, calculados com base na T estimada. O banco de dados da Estação Climatológica Principal de Santa Maria foi transformado em um banco de dados horários estimados de T e UR e foram obtidos os valores de severidade calculada (VSC) pelo sistema Blitecast em 14 datas de plantio da batata em 43 anos agrícolas. A estação meteorológica automática de Santa Maria, RS, pertencente ao INMET, apresenta 90,1% dos dias sem falhas de registros de dados em 10 anos, de 2002 a 2011. A temperatura mínima diária do ar em Santa Maria ocorreu com maior frequência às 09 h UTC, correspondendo às 06 h no horário oficial local, nos meses de setembro a fevereiro. De março até agosto, esse horário é atrasado, sendo a sua ocorrência mais frequente às 10 h UTC. A precisão das estimativas variou de 0,7 oC a 1,5 oC, com desvio médio de até 0,65oC para T do ar e de 0,7 % a 1,2 %, com desvio médio de até 4 %, para UR, dependendo do horário. Cultivos de batata no período de safrinha necessitam, em média, de um número 54 % maior de aplicações de fungicida em relação ao período de safra. Na safra o número mais provável de pulverizações oscila entre duas e quatro e na safrinha entre seis e sete. Plantios de batata realizados em agosto e em março exigiram um menor custo econômico, ecológico e de saúde do produtor na proteção da cultura contra a requeima do que plantios mais precoces (julho e fevereiro).

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