Doctor of Philosophy / Genetics Interdepartmental Program / Jesse A. Poland / Wheat is perhaps the most important component in human diet introduced since the conception of modern agriculture, which provides about 20% of the daily protein and calorie intake to billions of people. Adaptable to wide range of climates, wheat is grown worldwide, lending it the potential to mitigate the imminent risk of food security for future population of 9.5 billion people. For developing improved crop varieties in the future, genetic diversity is a key factor in plant breeding. Constraints in wheat evolution and artificial selection practices have resulted in erosion of this ingredient in elite germplasm. However, wheat wild relatives, such as Ae. tauschii, D-genome donor of wheat, are a storehouse for unexploited genetic diversity that can be used for improving wheat for disease and insect resistance, yield, quality, and tolerance to abiotic stresses. More than 1700 genebanks around the world hold over 7 million accessions of these wild relatives. These genebanks are expensive to maintain, therefore, efficient curation is necessary. We developed and implemented a protocol to identify duplicate accessions using genomic tools. Implementing this approach with three genebanks, we identified over 50% duplicated accessions across genebanks. There are over a million Triticeae accessions held collectively, and it is likely as more number of genebanks are tested, there will be decreasing number of unique accessions. Selecting and utilizing the wild genetic diversity is no easy task. Historically, breeders and geneticists have chosen the accessions primarily based on associated phenotypic data. Unless focusing on a targeted trait, this practice is imperfect in capturing the genetic diversity with some other limitations, such as confounding phenotypic data with the testing environment. Utilizing next-generation sequencing methods, we selected a MiniCore consisting of only 40 accessions out of 574 capturing more than 95% of the allelic diversity. This MiniCore will facilitate the use of genetic diversity present in Ae. tauschii for wheat improvement including resistance to leaf rust, stem rust, Hessian fly, and tolerance to abiotic stresses. Hessian fly is an important insect pest of wheat worldwide. Out of 34 known resistance genes, only six have been mapped on the D sub-genome. With swift HF evolution, we need to rapidly map and deploy the resistance genes. Some of the undefeated HF resistance genes, such as H26 and H32, were introgressed from Ae. tauschii. In this study, we mapped three previously known genes, and a new gene from Ae. tauschii accession KU2147. Genes were mapped on chromosomes 6B, 3D, and 6D. Further, identification and cloning of resistance genes will enhance our understanding about its function and mode of action. In conclusion, wild wheat relatives are genetically diverse species, and utilizing the novel genetic diversity in Ae. tauschii will be fruitful for wheat improvement in the wake of climate change to ensure future food security to expected 2 billion newcomers by 2050.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2017-03-13T14:15:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE HENRIQUE PADILHA!.pdf: 2745123 bytes, checksum: 6c3cc4bc0855288de567f8b22b28debe (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-17T21:15:43Z (GMT) No. of bitstreams: 2 TESE HENRIQUE PADILHA!.pdf: 2745123 bytes, checksum: 6c3cc4bc0855288de567f8b22b28debe (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-17T21:15:43Z (GMT). No. of bitstreams: 2 TESE HENRIQUE PADILHA!.pdf: 2745123 bytes, checksum: 6c3cc4bc0855288de567f8b22b28debe (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-21 / O consumo de pimentas (Capsicum, Solanaceae) vem aumentando progressivamente, devido à diversidade, multiplicidade dos usos e propriedades funcionais dos seus frutos. Um dos problemas que limita a produtividade de pimentas é a antracnose, doença fúngica recorrente na região sul do Brasil, que resulta em prejuízos ao produtor e ao consumidor. Frente a esse problema, a ampla diversidade genética encontrada nas pimentas representa uma importante fonte para novas alternativas. O objetivo geral deste trabalho foi contribuir para a caracterização de recursos genéticos de pimentas do gênero Capsicum. A tese está apresentada na forma de três capítulos, cujos objetivos foram caracterizar morfologicamente acessos de pimentas do Banco Ativo de Germoplasma de Capsicum da Embrapa Clima Temperado, avaliar a divergência genética e estimar a entropia dos caracteres avaliados; avaliar a reação de acessos de pimentas à antracnose e identificar possíveis fontes de resistência; e realizar a avaliação metabolômica de acessos de pimentas contrastantes para resposta à antracnose. No primeiro capítulo, foram caracterizados 21 acessos de pimentas (C. baccatum e C. chinense) com o uso de 47 descritores morfológicos. Foi verificada ampla diversidade genética para os caracteres avaliados. Os descritores posição da flor, posição do estigma, cor de fruto maduro, pungência e comprimento de planta apresentaram elevada entropia. No segundo capítulo, os mesmos acessos foram avaliados quanto à resposta à antracnose. Os frutos foram colhidos e inoculados em duas fases de maturação. Foi possível diferenciá-los a partir da inoculação com um isolado do fungo Colletotrichum acutatum. Os acessos avaliados não apresentaram resistência total à antracnose. Foi observada variação para resposta à antracnose. A resistência de pimentas à antracnose se expressa de forma diferente de acordo com a fase de maturação do fruto. Dentre os acessos avaliados, P27 apresentou maior resistência à doença e P175 maior suscetibilidade. No terceiro capítulo, foi realizada a avaliação metabôlomica dos frutos dos acessos contrastantes para a resistência à antracnose. Para as análises foram utilizadas técnicas de cromatografia líquida, gasosa e espectrometria de massas. A concentração de metabólitos especializados em frutos de pimentas varia conforme a fase de maturação. A concentração de capsaicinoides e capsinoides dos frutos não influencia a resistência à antracnose. A produção dos compostos butano-2,3-diol, L-threitol, D-frutose e α-D-glucopyranoside nos frutos foi alterada pela incidência da antracnose. O estudo da relação dos compostos dos frutos de pimenta em resposta ao ataque do patógeno gera informações sobre o processo de resistência e suscetibilidade, assim como desperta novos estudos que busquem elucidar a compressão da interação planta-patógeno e uso de recursos genéticos para obtenção de genótipos resistentes. / The consumption of peppers (Capsicum, Solanaceae) increases progressively, due to diversity, multiplicity of usage and the functional properties of the fruits. One of the problems that limit the peppers produtivity is anthracnose, a recurrent fungal disease in South of Brazil, results in losses to producers and consumers. Facing this problem, the wide genetic diversity found in peppers represents an important source of new alternatives. The general objective of this work was to contribute to the characterization of genetic resources of Capsicum peppers. The thesis is presented in form of three chapters, whose objectives were to perform morphological characterization of peppers accessions from the Capsicum Genebank of Embrapa Temperate Agriculture, to evaluate the genetic divergence and estimate the entropy of descriptors; we performed the evaluation of peppers accessions reaction to anthracnose, as well as to identify possible new sources of resistance; and to perform the metabolomic evaluation of contrasting peppers accessions to anthracnose response. In the first chapter, 21 accessions of peppers (C. baccatum and C. chinense) were characterized using 47 morphological descriptors. A wide genetic diversity was verified for the evaluated characters. The descriptors flower positon, stigma position, ripe fruit color, pungence and plant length presented high entropy. In the second chapter, the same accessions were evaluated for anthracnose response. It was possible to differentiate them through inoculation of Colletotrichum acutatum isolate. The fruits were detached and inoculated in two maturation stage. Accessions did not present complete resistance to anthracnose. Great genetic diversity was observed to anthracnose response. Anthracnose resistance of peppers was expressed differently according to fruit maturation stage. Among evaluated accessions, P27 presented greater resistance to the disease and P175 more susceptibility. In the third chapter, metabomic evaluation of contrasting accessions for anthracnose resistance was performed. Liquid chromatography, gas chromatography and mass spectrometry were used for analyzes. Different metabolomic responses were observed for pepper accessions. The concentration of specialized metabolites in peppers fruits varies according to maturation stage. Capsaicinoids and capsinoids content in fruits did not influence resistance to anthracnose. The production of butane-2,3-diol, L-threitol, D-fructose and α-Dglucopyranoside in fruits was affected by anthracnose. The study of relationship of pepper fruit compounds in response to pathogen's attack, generates information about resistance and susceptibility process, as well as instigates new studies that aim to understand the plant-pathogen interaction and the usage of genetic resources to obtain resistant genotypes.

This study records all known legume (Leguminosae/Fabaceae) species indigenous to South Africa, Lesotho and Swaziland to establish distribution patterns and optimum climatic and soil conditions for growth. The main purpose was to propose a list of legume species for further evaluation of their pasture potential. Collection data supplied by the National Herbarium (PRE) Computerised Information System were recorded to establish the distribution patterns of species based on the bioregions vegetation map. A total of 1 654 species are known to be indigenous, representing 24 tribes and 122 genera. The grouping of legume species into five main clusters and 16 Leguminochoria is ecologically described, with the highest legume species richness found in the Northern Mistbelt Forest. Key and diagnostic species are provided for each Leguminochorion. Soil pH and mean annual minimum temperature were found to be the main drivers for distinguishing between legume assemblages. The optimum climatic and soil conditions for growth are described as well as the available descriptive attributes for species recorded. Information on the range of tolerance of most species to abiotic factors is presented. Mean annual rainfall and soil pH are highly correlated with the distribution pattern of most species, followed by mean annual minimum temperature. Legume species adapted to a wide range of soil pH levels and low soil phosphorus levels are recorded. Existing data on the cultivation and grazing or browsing status of indigenous legumes were used to select 584 species found mainly in the Central Bushveld, Mopane and Lowveld Bioregions to be further evaluated for their pasture potential. Known characteristics were used to categorise species. Species contained in the tribe Phaseoleae are of special interest since it contains most of the genera with present-day agricultural value, i.e. Eriosema, Rhynchosia and Vigna species are listed as having high potential as pasture species. This study has shown that the descriptive and distribution data accumulated by botanists (notably taxonomists) could be of beneficial use in meeting agricultural objectives. Indigenous legumes are adapted to a wide range of soil and climatic conditions and represent a valuable but largely unexploited natural resource for pasture development and soil conservation practices. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Plant Science / unrestricted

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-22T19:16:20Z No. of bitstreams: 1 2014 - Aur?lio Ludovico de Almeida Martinez.pdf: 2604129 bytes, checksum: d6ebe0ec048ae2a4b877b584b5f65e6f (MD5) / Made available in DSpace on 2017-08-22T19:16:20Z (GMT). No. of bitstreams: 1 2014 - Aur?lio Ludovico de Almeida Martinez.pdf: 2604129 bytes, checksum: d6ebe0ec048ae2a4b877b584b5f65e6f (MD5) Previous issue date: 2014-07-28 / CAPES / Originating from Americas, with Brazil as an important center of diversity, Capsicum occupies an important position among greenery. This study aimed to 1) to assess the genetic similarity and presence of duplicates; 2) to evaluate the resistance to anthracnose disease 3) screening viruses resistance in Capsicum baccatum accessions from Instituto Federal Goiano - Campus Ceres genebank. The genetic similarity was determined by molecular characterization at Embrapa Recursos Gen?ticos e Biotecnologia through RAPD and ISSR markers and morphological descriptors defined for Capsicum spp. According to the molecular and morphological characterization it was confirm the genetic diversity among C. baccatum accessions and the lack of duplicates. The anthracnose resistance was evaluated at 50 and 120 days after the dispersion of pepper powder prepared from infected peppers, considering incidence (presence or absence of lesions in fruits) and disease severity (surface damage percentage to the surface total of fruit) through images processing of diseased fruits. The essay was carried out under field conditions, using augmented randomized complete block design with fifteen plants per plot and three commercial varieties as control. Significant difference was observed especially in disease severity between treatments in both periods observed. The viruses incidence was evaluated in two field experiments in the periods between June-December 2012 and January-June 2013. DAS-ELISA test was performed with absorbance reading at 405 nm on a plate reader, all symptomatic and four asymptomatic plants in all plots was sampled, at 180 days after transplanting in the first experiment, and 160 days after transplanting in second one. The Viruses evaluated were tobamovirus Pepper mild motle virus (PMMoV), the cucumovirus Cucumber mosaic virus (CMV), the tospovirus Groundnut ring spot virus (GRSV), Tomato spot wilt virus (TSWV) and Tomato chlorotic spot virus (TCSV) and potyvirus Potato virus Y (PVY) and Pepper yellow mosaic virus (PepYMV). The percentage of incidence in the first and second period evaluated, were 30% e 7% PMMoV, 6% e 27% CMV, 8% e 12% PVY, 25% e 22% PepYMV, 10% e 2% GRSV, 11% e 0% TCSV, 0% e 11% TSWV. Virus were not detected several accessions studied and are potential sources of virus resistance that should be confirmed on resistance testing under controlled conditions. / Origin?rias das Am?ricas e tendo o Brasil como importante centro de diversidade, as pimentas do g?nero Capsicum ocupam posi??o de destaque entre as hortali?as. O presente trabalho teve como objetivos: 1) verificar a similaridade gen?tica e a presen?a de duplicatas; 2) avaliar a resist?ncia ? Colletotrichum spp.; e 3) avaliar a incid?ncia de viroses em acessos de Capsicum baccatum da cole??o de germoplasma do Instituto Federal Goiano - Campus Ceres. A similaridade gen?tica foi determinada pela caracteriza??o molecular realizada na Embrapa Recursos Gen?ticos e Biotecnologia, por meio de marcadores ISSR e RAPD e descritores morfol?gicos definidos para Capsicum spp. De acordo com a caracteriza??o molecular e morfol?gica p?de-se verificar diversidade gen?tica entre os acessos C. baccatum e a inexist?ncia de duplicatas na cole??o. A resist?ncia ? antracnose foi avaliada aos 50 e 120 dias ap?s a dispers?o de p? de pimenta preparado a partir de frutos infectados, considerando incid?ncia (presen?a e aus?ncia de les?es no fruto) e severidade de doen?a (percentual de superf?cie de les?o em rela??o ? superf?cie total do fruto), a partir do processamento de imagens dos frutos doentes. A avalia??o foi realizada em condi??es de campo, utilizando desenho experimental em blocos completos casualizados aumentados com quinze plantas por parcela e tr?s variedades comerciais como testemunhas. Foi observada diferen?a significativa entre os tratamentos, especialmente na severidade da doen?a, nos dois per?odos observados. A incid?ncia de viroses foi avaliada em dois experimentos conduzidos em campo, nos per?odos entre junho a dezembro 2012 e janeiro a junho de 2013. Foi realizado teste DAS-Elisa, com leitura de absorb?ncia a 405 nm em leitora de placas, em amostras das plantas sintom?ticas e quatro plantas assintom?ticas em todas as parcelas. Os v?rus avaliados foram o tobamovirus Pepper mild motle virus (PMMoV), o cucumovirus Cucumber mosaic virus (CMV), os tospovirus Groundnut ring spot virus (GRSV), Tomato spot wilt virus (TSWV) e Tomato chlorotic spot virus (TCSV) e os potyvirus Potato virus Y (PVY) e Pepper yelow mosaic virus (PepYMV). No per?odo de junho a dezembro de 2012, os v?rus detectados e respectivo percentual de incid?ncia foram PMMoV 30%, CMV 6%, PVY 8%, PepYMV 25%, GRSV 10%, TCSV 11%, TSWV 0%. J? no per?odo de janeiro a junho de 2013, o percentual de incid?ncia dos respectivos v?rus foram: PMMoV 7%, CMV 27%, PVY 12%, PepYMV 22%, GRSV 2%, TCSV 0% e TSWV 11%. Para todos os v?rus estudados, houveram acessos nos quais n?o foi detectada a presen?a do v?rus, com destaque para IFET 64 (n?o detectado PMMoV, CMV, PepYMV e PVY), IFET 273, (n?o detectados PMMoV, PVY, TSWV, TCSV e GRSV, IFET 19 (n?o detectado CMV, PVY, TSWV, TCSV e GRSV).

Landwirtschaftliche Systeme müssen sich immerfort an Druckfaktoren wie Klimawandel und Bevölkerungswachstum anpassen. Hierbei spielt die genetische Vielfalt von Pflanzen eine wichtige Rolle, da diese für die Sicherung der Ernährung und des Einkommens von entscheidender Bedeutung ist. Dennoch wird der wirtschaftliche Wert pflanzengenetischer Ressourcen selten untersucht. Um diese Forschungslücke zu schließen, werden in dieser Arbeit drei Bewertungen vorgestellt, welche die wirtschaftlichen Werte pflanzengenetischer Ressourcen untersuchen. Im Rahmen dieser Dissertation werden zwei verschiedene Agrarsystemen analysiert. Diese unterscheiden sich hinsichtlich des Klimas, der agrarökologischen Bedingungen, der landwirtschaftlichen Praxis, der politischen und ökonomischen Rahmenbedingungen sowie der soziokulturellen Verankerung der Kulturart. Die ersten beiden Analysen befassen sich mit der Züchtung und Produktion von Winterweizen in Deutschland. Charakterisiert sind diese durch ein gemäßigtes Klima und intensive Anbaubedingungen. In diesem System überwiegen moderne Sorten, die in einem formalisierten Züchtungsprozess entstanden sind. Es werden die folgenden Forschungsfragen beantwortet: 1) Was ist der ökonomische Wert, der durch den Austausch von Zuchtmaterial entsteht? und 2) Wie hoch ist der mikroökonomische Wert von Resistenzzüchtung? In der dritten Analyse wird ein weiteres Agrarsystem vorgestellt: Die Andenlandwirtschaft, wo im Hochland unter extensiven Bedingungen eine Vielzahl von Kartoffellandrassen angebaut wird. Dort wird folgende Frage analysiert: 3) Welche Mehrwerte wurden durch die Repatriierung oder Neuverteilung von Kartoffellandrassen erzielt? Diese Analysen zeigen, dass die Verfügbarkeit, der Austausch und die Nutzung von pflanzengenetischen Ressourcen die Agrarproduktion verbessern; es entstehen sowohl sektorale, mikroökonomische als auch ernährungsbezogene und kulturelle Mehrwerte. / Agricultural systems must constantly adapt to pressuring events such as climate change and population growth to maintain and improve production processes in a sustainable manner. Thereby the genetic diversity of plants used in agriculture constitute a strategic asset. Nevertheless, their economic value is often overlooked. To fill this research gap, this thesis presents three assessments that produce more evidence on the economic value of plant genetic resources. Two very distinct agricultural systems are discussed. These differ greatly in terms of climate, agroecological conditions, farming practices, seed systems, political and economic frameworks, and the socio-cultural embeddedness of the crop in question. The first two assessments are concerned with winter wheat (Triticum aestivum) breeding and production in the temperate climate and intensive growing conditions in Germany. Modern cultivars created in a formalized breeding process prevail in this system. The following two research questions are elaborated: 1) What is the economic value of exchanging breeding material? and 2) What is the microeconomic value of resistance breeding? The third assessment presents a different agricultural system: Andean agriculture, where a wide variety of potato landraces (Solanum spp.) are grown extensively in the Peruvian highlands. In this case, the research question I investigated is: 3) What are the benefits of repatriating (i.e., redistributing) potato landraces to Andean farmers? These studies demonstrate that the availability, exchange, and adoption of plant genetic resources, which are well adapted to and culturally embedded in specific agricultural systems, improve the overall quantity and sustainability of agricultural production. These improvements can be translated into sectoral, microeconomic as well as nutritional and cultural benefits.