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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Non-prior service accessions and the Naval Reserve: readiness and recruiting

Hobson, Alexandra I. 06 1900 (has links)
Approved for public release, distribution is unlimited / This study examines the Reserve Non-Prior Service Accession (NPS) program, the effects of the current training process for Reserve readiness, and the effects of proposals to extend the initial active duty training period. In particular, the thesis examines the effects of the extended training programs on recruiting using data derived from a web-based survey of NPS Reservists. Multivariate logistic regression models are used to examine the effects of personal demographic characteristics on an individual's likelihood to enlist in the NPS program for a 28-day or a 77-day active duty training period. Separate models are used for each program and include a model with the Delayed Entry Program (DEP) as an option, and a model without it. Respondents report that they would have been slightly less inclined to enlist under the 28-day options whereas under the 77-day options respondents indicated that they would have been much less inclined to enlist. FY03 cost data is used to conduct the cost-effectiveness analysis, and indicates that the 28-day option would save an estimated $2.8 million, and decrease NPS personnel training time by 5 months. The 77-day option would cost an estimated additional $46.1 million and decrease NPS personnel training time by 21 months. Based on the analysis of this thesis, it is recommended that the current NPS accession program be phased out and the 77-day with DEP training alternative be implemented. Additionally, the recruiting focus should shift to target high school senior and recent graduates. / Lieutenant Commander, United States Naval Reserve
2

Managing Soybean Cyst Nematode by Utilizing Cover Crops and Resistant Sources from Early Maturing Soybean Accessions

Acharya, Krishna January 2020 (has links)
Greenhouse and microplot studies were conducted for understanding the effects of cover crop species/cultivars for hosts and population reduction of soybean cyst nematode (SCN; Heterodera glycines) from the fields of North Dakota. Moreover, early-maturing soybean [Glycine max (L.)] accessions from different countries of origin were screened for resistance against two common SCN populations for finding new sources of resistance. Thirty-eight cover crop species/cultivars were evaluated for their hosting ability of two SCN populations (SCN103 and SCN2W) from two fields of North Dakota in greenhouse experiments. The majority of the tested crops were non-hosts for both SCN populations. However, a few of them, such as Austrian winter pea (Pisum sativum L.), crimson clover (Trifolium incarnatum L. cv. Dixie), crambe (Crambe abyssinica, cv. BelAnn), field pea, cvs. Aragorn and Cooper, hairy vetch (Vicia villosa Roth), turnip (Brassica rapa L. cv. Purple top), and white lupine (Lupinus albus L.) were poor-hosts/hosts of both SCN populations. Furthermore, thirteen of them were tested for the SCN population reduction either or both in the greenhouse and microplot experiments. Out of 13, at least four crops, such as annual ryegrass (Lolium multiflorum L.), brown mustard (Brassica juncea L. cv. Kodiak), daikon radish (Raphanus sativus L.), and turnip cv. Pointer showed more than 50% population reduction compared with initial population densitiy, consistently in the greenhouse or microplot experiments. The resistance screening of 152 early-maturing soybean accessions showed that a majority of the accessions were susceptible/moderately susceptible to both SCN populations (SCN HG type 0 and 2.5.7), while a few (n=18) showed good resistance responses to both or either of the SCN populations. The cover crops, which were non-hosts/poor-hosts and have a greater ability for the SCN population reduction have great potential to be included in an integrated SCN management strategy. The novel resistant accessions identified in this study have the potential to be used in soybean breeding for developing SCN-resistant cultivars after confirming their resistance response and identifying the resistance genes/loci. The results obtained from this study helps in developing a sustainable SCN management strategy in the northern Great Plains.
3

Control of shoot and root growth by water deficit in Arabidopsis thaliana : a parallel analysis using artificial and natural mapping populations / Contrôle des croissances foliaires et racinaires en situation de déficit hydrique : analyse comparée de populations de cartographie naturelles et artificielles

Bouteillé, Marie 11 July 2011 (has links)
Le maintien de la croissance foliaire en situation de déficit hydrique résulte du maintien de l´absorption racinaire et de la production de biomasse au niveau foliaire. Pour optimiser les deux processus, la plante ajuste la croissance de ses organes, et la répartition de la biomasse produite, entre les différents organes (root/shoot ratio) ou au sein de chaque organe (surface foliaire spécifique, longueur racinaire spécifique). Les principaux objectifs de ce travail de thèse étaient (i) d´évaluer l´impact des modifications de répartition de biomasse sur le maintien de la croissance foliaire en situation de déficit hydrique, (ii) de relier la réponse de la croissance d´un génotype aux caractéristiques de son habitat d´origine, and (iii) d´identifier les régions du génome responsables de la variation des croissances foliaires et racinaires en situation de déficit hydrique. Différent types de populations d´Arabidopsis thaliana ont été utilisés, une population de lignées recombinantes, ainsi que différents groupes d´accessions collectées dans des environnements naturels contrastés. Une analyse des relations allométriques entre les variables foliaires et racinaires en conditions de culture optimales puis en situation de déficit hydrique a permis de mettre en évidence le rôle clé de la surface foliaire spécifique dans l´amélioration de la tolérance au déficit hydrique. Une caractérisation détaillée du climat des régions dans lesquelles les accessions avaient été collectées a permis de faire le lien entre la tolérance accrue de certains génotypes et la faible balance climatique dans laquelle ils évoluaient. Enfin, en utilisant ces génotypes, une analyse de génétique quantitative (combinant recherche de QTL et génétique d´association) a été menée. Les régions génomiques controllant les croissances foliaires et racinaires étaient très liées, en particulier en situation hydrique optimale, mais le calcul de variables utilisant la croissance de la plante comme cofacteur a permis d´identifier des régions spécifiques de la croissance racinaire, dont une a été confirmée en utilisant des lignées quasi isogéniques. En situation de contrainte hydrique, les déterminants génétiques des croissances foliaires et racinaires étaient moins liés, et plusieurs régions très fortement associées spécifiquement aux variations de croissance racinaire ou foliaire ont été détectées. Des régions associées au maintien de la croissance foliaire en situation de déficit hydrique ont pu être mises en évidence, et la précision des études de génétique d´association a permis de réveler la présence de gènes d´intéret dans ces régions. / Growth maintenance under water deficit mainly results from the maintenance of water uptake at the root level,and assimilates production by leaves. To optimize both processes, plant need to adjust organ growth and biomassallocation patterns between roots and shoots (root/shoot ratio), but also within the organs, through specific leaf areaand specific root length variations. The main objectives of this study were (i) to evaluate the impact of growth andbiomass allocation patterns modifications on growth maintenance under drought conditions, (ii) to rely the genotypicresponses to water deficit conditions and the climatic features of the natural environment in which they evolved, and(iii) to identify the key genetic regions responsible for shoot and root growth variation in response to water deficitconditions. We used different sets of genotypes, a population of recombinant inbred lines, and different sets ofaccessions of Arabidopsis thaliana, collected in a wide range of environments. An analysis of the allometricrelationships between shoot and root growth related variables under both well watered and water deficit conditionsallowed to highlight the importance of specific leaf area plasticity to maintain plant growth under water deficit. Adetailed climatic characterization of the natural habitats of the accessions studied, combined to the evaluation ofgrowth response to water deficit in these accessions allowed connecting low climatic water balance to better toleranceto water deficit conditions in specific regions, suggesting that this climatic feature could have shaped the evolution ofgenotypes in certain regions. Finally, using these two sets of genotypes, joint linkage and linkage disequilibriumanalysis were performed on growth related traits under well watered and water deficit conditions. Some genetic regionsinvolved in the control of root and shoot related traits were strongly coupled, especially in well watered experiments,but we managed to identify root specific regions using calculated variables that takes global plant growth as a cofactor.Under water deficit, the regions controlling root and shoot growth were less associated, and very strong QTL weredetected, specifically associated to one or the other part. Genomic regions associated to growth response to waterdeficit were also detected, and the accuracy of association mapping enabled to identify target genes that could be playa role in growth maintenance under drought.
4

Resistência de genótipos de meloeiro à mosca-minadora Liriomyza sativae (Blanchard, 1938) (Diptera: Agromyzidae) / Resistance of melon genotypes to the leafminer Liriomyza sativae (Blanchard, 1938) (Diptera: Agromyzidae)

Lima, Marcos Aurélio Araujo 03 July 2012 (has links)
Atualmente, a mosca-minadora Liriomyza sativae (Diptera: Agromyzidae) é uma das principais pragas da cultura do meloeiro no Brasil. É comumente relatado que as moscas-minadoras se tornam pragas devido a um desequilíbrio biológico provocado pelo uso incorreto de inseticidas além do seu grande potencial biótico. Portanto, é fundamental que sejam desenvolvidas estratégias de manejo que atuem em equilíbrio com o ambiente. Assim, a resistência de plantas a insetos assume papel fundamental nesse contexto. Diante desses fatos, a presente pesquisa objetivou avaliar a resistência de genótipos de meloeiro à mosca-minadora. A criação do inseto foi mantida em plantas de feijão-caupi. Foram realizados ensaios preliminares com diferentes números de casais e diferentes tempos de exposição das plantas aos insetos visando determinar a combinação mais adequada para estudos de resistência. Os resultados indicaram que são necessários quatro casais/planta e um tempo mínimo de infestação de 24 horas. Foram testados inicialmente 44 genótipos divididos em cinco grupos, comparados sempre a uma testemunha suscetível (Vereda). Cada grupo foi mantido numa gaiola onde ocorreu a infestação pelos adultos. Após cinco dias, foi avaliado o número de minas por planta, com base no que foi calculado o Índice de Resistência. A partir desse índice, foram selecionados, os oito genótipos mais promissores (os acessos A5, A15, A22, A29, A42 e A44 e as cultivares Mc Laren e Guaporé) para avaliação dos possíveis tipos de resistência envolvidos. No teste de antixenose para oviposição, constatouse que, no teste de livre escolha, todos os genótipos foram menos preferidos para oviposição que a testemunha, enquanto no teste de confinamento os menos preferidos foram os genótipos A5, A22, A29, A42, A44 e Guaporé. Os genótipos A22, A29, A42, A44 e Mc Laren prolongaram a duração do período embrionário do inseto, enquanto a cultivar Guaporé provocou sobrevivência larval nula e Mc Laren prolongou a fase larval e, juntamente com o acesso A44, reduziu a sobrevivência dessa fase. Por outro lado, o acesso A15 foi o que proporcionou a maior duração da fase de pupa, sendo o tamanho pupal reduzido pelos acessos A29, A42 e A44. A maior duração da fase imatura do inseto ocorreu nos genótipos A29 e Mc Laren. Os diferentes genótipos de meloeiro não influenciaram a longevidade, a razão sexual, os períodos de pré-oviposição e de oviposição e a fecundidade total dos adultos de L. sativae. Com base na avaliação do efeito dos genótipos sobre a biologia do inseto, constatou-se que Mc Laren, Guaporé, A22, A29, A42 e A44 apresentam resistência do tipo antibiose e/ou antixenose para alimentação. No ensaio de tolerância, concluiu-se que a quantidade de clorofila nas folhas foi um parâmetro adequado para caracterizar o efeito do ataque de L. sativae sobre o meloeiro; por outro lado, os pesos de matéria fresca e seca e o comprimento do ramo principal não foram parâmetros adequados para avaliação da tolerância. Considerando todos os parâmetros estudados nesse ensaio, os genótipos A44 e Guaporé se comportaram como tolerantes. / Nowadays, the vegetable leafminer Liriomyza sativae (Blanchard) (Diptera: Agromyzidae) is one of the major melon pests in Brazil. The outbreak of this pest has been frequently reported to be due to biological control disruptions caused by the incorrect use of insecticides and to its high biotic potential. Therefore, it is important that management strategies acting in balance with the environment are developed. Studies on host plant resistance to insects play a fundamental role in this context. In this research project, we intended to evaluate the resistance of melon genotypes to the vegetable leafminer. The insect population was reared under laboratory conditions on bean plants. Preliminary assays were carried out with different numbers of couples and different infestation times aiming to find the most adequate combination to be used in plant resistance studies. The best results were obtained with four couples per plant and 24 hours of infestation. Initially, 44 melon genotypes were screened in five groups of nine genotypes compared to a susceptible control genotype (Vereda). Each group was placed in one cage for infestation with adult leafminer flies. After four days, the mean number of mines per plant was evaluated. Based on this data, the Resistance Index was estimated and eight genotypes were selected (accessions A5, A15, A22, A29, A42 and A44 and cultivars Mc Laren and Guapore). In the oviposition preference study, all genotypes were less preferred than the control in the multiple-choice test while in the no-choice test genotypes A5, A22, A29, A42, A44 and Guaporé was less preferred. Egg duration was longer in genotypes A22, A29, A42, A44 and Mc Laren than in control. In Guapore no larvae survived while in A44 and Mc Laren larval survival was smaller than in control, moreover in Mc Laren larval duration was longer than in control. Accession A15 provided the longest pupal duration, while accessions A29, A42 and A44 presented the smallest pupal sizes. In genotypes A29 and Mc Laren the egg-adult period was longer than the control. The different genotypes did not affect longevity, sex ratio, preoviposition and oviposition periods and fecundity of females. Based on the evaluation of host plant effect on the vegetable leafminers biology it was established that the genotypes A22, A29, A42, A44, Mc Laren and Guapore present resistance by antibiosis and/or antixenosis for feeding. In the tolerance test, it was concluded that chlorophyll content was an adequate parameter for discriminating the genotypes in relation to attack by L. sativae; on the other hand, main branch length and fresh and dry weight were not adequate parameters for tolerance study. Based on all parameters evaluated, genotypes A44 and Guapore seems to be tolerant.
5

Metabolic interactions in leaf development in Arabidopsis thaliana

Ivakov, Alexander January 2011 (has links)
Das Wachstum und Überleben von Pflanzen basiert auf der Photosynthese in den Blättern. Diese beinhaltet die Aufnahme von Kohlenstoffdioxid aus der Atmosphäre und das simultane Einfangen von Lichtenergie zur Bildung organischer Moleküle. Diese werden nach dem Eintritt in den Metabolismus in viele andere Komponenten umgewandelt, welche die Grundlage für die Zunahme der Biomasse bilden. Blätter sind Organe, die auf die Fixierung von Kohlenstoffdioxid spezialisiert sind. Die Funktionen der Blätter beinhalten vor allem die Optimierung und Feinregulierung vieler Prozesse, um eine effektive Nutzung von Ressourcen und eine maximale Photosynthese zu gewährleisten. Es ist bekannt, dass sich die Morphologie der Blätter den Wachstumsbedingungen der Pflanze anpasst und eine wichtige Rolle bei der Optimierung der Photosynthese spielt. Trotzdem ist die Regulation dieser Art der Anpassung bisher nicht verstanden. Die allgemeine Zielsetzung dieser vorliegenden Arbeit ist das Verständnis wie das Wachstum und die Morphologie der Blätter im Modellorganismus Arabidopsis thaliana reguliert werden. Besondere Aufmerksamkeit wurde hierbei der Möglichkeit geschenkt, dass es interne metabolische Signale in der Pflanze geben könnte, die das Wachstum und die Entwicklung von Blättern beeinflussen. Um diese Fragestellung zu untersuchen, muss das Wachstum und die Entwicklung von Blättern oberhalb des Levels des einzelnen Organs und im Kontext der gesamten Pflanze betrachtet werden, weil Blätter nicht eigenständig wachsen, sondern von Ressourcen und regulatorischen Einflüssen der ganzen Pflanze abhängig sind. Aufgrund der Komplexität dieser Fragestellung wurden drei komplementäre Ansätze durchgeführt. Im ersten und spezifischsten Ansatz wurde untersucht ob eine flussabwärts liegende Komponente des Zucker-Signalwegs, Trehalose-6-Phosphat (Tre-6-P), das Blattwachstum und die Blattentwicklung beinflussen kann. Um diese Frage zu beantworten wurden transgene Arabidopsis-Linien mit einem gestörten Gehalt von Tre-6-P durch die Expression von bakteriellen Proteinen die in dem metabolismus von trehalose beteiligt sind. Die Pflanzen-Linien wurden unter Standard-Bendingungen in Erde angebaut und ihr Metabolismus und ihre Blattmorphologie untersucht. Diese Experimente führten auch zu einem unerwarteten Projekt hinsichtlich einer möglichen Rolle von Tre-6-P in der Regulation der Stomata. In einem zweiten, allgemeineren Ansatz wurde untersucht, ob Änderungen im Zucker-Gehalt der Pflanzen die Morphogenese der Blätter als Antwort auf Licht beeinflussen. Dazu wurden eine Reihe von Mutanten, die im Zentralmetabolismus beeinträchtigt sind, in derselben Lichtbedingung angezogen und bezüglich ihrer Blattmorphologie analysiert. In einem dritten noch allgemeineren Ansatz wurde die natürliche Variation von morphologischen Ausprägungen der Blätter und Rosette anhand von wilden Arabidopsis Ökotypen untersucht, um zu verstehen wie sich die Blattmorphologie auf die Blattfunktion und das gesamte Pflanzenwachstum auswirkt und wie unterschiedliche Eigenschaften miteinander verknüpft sind. Das Verhältnis der Blattanzahl zum Gesamtwachstum der Pflanze und Blattgröße wurde gesondert weiter untersucht durch eine Normalisierung der Blattanzahl auf das Frischgewicht der Rosette, um den Parameter „leafing Intensity“ abzuschätzen. Leafing Intensity integrierte Blattanzahl, Blattgröße und gesamtes Rosettenwachstum in einer Reihe von Kompromiss-Interaktionen, die in einem Wachstumsvorteil resultieren, wenn Pflanzen weniger, aber größere Blätter pro Einheit Biomasse ausbilden. Dies führte zu einem theoretischen Ansatz in dem ein einfaches allometrisch mathematisches Modell konstruiert wurde, um Blattanzahl, Blattgröße und Pflanzenwachstum im Kontext der gesamten Pflanze Arabidopsis zu verknüpfen. / Plant growth and survival depend on photosynthesis in the leaves. This involves the uptake of carbon dioxide from the atmosphere and the simultaneous capture of light energy to produce organic molecules, which enter metabolism and are converted to many other compounds which then serve as building blocks for biomass growth. Leaves are organs specialised for photosynthetic carbon dioxide fixation. The function of leaves involves many trade-offs which must be optimised in order to achieve effective use of resources and maximum photosynthesis. It is known that the morphology of leaves adjusts to the growth environment of plants and this is important for optimising their function for photosynthesis. However, it is unclear how this adjustment is regulated. The general aim of the work presented in this thesis is to understand how leaf growth and morphology are regulated in the model species Arabidopsis thaliana. Special attention was dedicated to the possibility that there might be internal metabolic signals within the plant which affect the growth and development of leaves. In order to investigate this question, leaf growth and development must be considered beyond the level of the single organ and in the context of the whole plant because leaves do not grow autonomously but depend on resources and regulatory influences delivered by the rest of the plant. Due to the complexity of this question, three complementary approaches were taken. In the first and most specific approach it was asked whether a proposed down-stream component of sucrose signalling, trehalose-6-phosphate (Tre-6-P), might influence leaf development and growth. To investigate this question, transgenic Arabidopsis lines with perturbed levels of Tre-6-P were generated using the constitutive 35S promoter to express bacterial enzymes involved in trehalose metabolism. These experiments also led to an unanticipated project concerning a possible role for Tre-6-P in stomatal function, which is another very important function in leaves. In a second and more general approach it was investigated whether changes in sugar levels in plants affect the morphogenesis of leaves in response to light. For this, a series of metabolic mutants impaired in central metabolism were grown in one light environment and their leaf morphology was analysed. In a third and even more general approach the natural variation in leaf and rosette morphological traits was investigated in a panel of wild Arabidopsis accessions with the aim of understanding how leaf morphology affects leaf function and whole plant growth and how different traits relate to each other. The analysis included measurements of leaf morphological traits as well as the number of leaves in the plant to put leaf morphology in a whole plant context. The variance in plant growth could not be explained by variation in photosynthetic rates and only to a small degree by variation in rates of dark respiration. There were four key axes of variation in rosette and leaf morphology – leaf area growth, leaf thickness, cell expansion and leaf number. These four processes were integrated in the context of whole plant growth by models that employed a multiple linear regression approach. This then led to a theoretical approach in which a simple allometric mathematical model was constructed, linking leaf number, leaf size and plant growth rate together in a whole plant context in Arabidopsis.
6

The origin of naked barley (Hordeum vulgare L. ssp. vulgare) studied bythe nud gene

Gustafsson, Dan January 2013 (has links)
The exact origin of the peculiar naked barley is somewhat illusive. There   is a debate whether it has a single, monophyletic origin or a multiple, paraphyletic origin. It is from previous Asian studies on naked   barley known that a mutation   or a deletion of the nud gene expresses the   naked seed phenotype. Not much   investigation has been done outside of   Asia, least of all in the Nordic countries, on what gives naked   barley its character. Therefore this   study was set up to examine if   the Nordic variant of naked barley shares   the same nud allele as the Asian   and thus has a   close connection with it, or   if they have independent mutations. I   could confirm that the known alleles of the nud gene do determine the seed character of barley. Most of the   results of the PCR genotyping confirmed the phenotype of the tested   accessions, both naked and hulled barleys. However, one visually phenotyped naked   barley cultivar (NGB4580) still amplified with the known primers that would   match the Asian hulled allele, meaning that the Nordic accession NGB4580 of   naked barley did not carry the known nud   deletion. This suggests that naked barley has arisen independently in Asia   and in the Nordic countries.
7

Evaluation of cowpea (Vigna unguiculata L. Walp) genotypes for adaptation to low soil-phosphorus conditions and to rock phosphate application

Mahamane, Sabiou 15 May 2009 (has links)
Cowpea (Vigna ungiculata L. Walp) is a major food and fodder legume in poor countries, particularly Sub-Saharan Africa countries. It is generally produced in sandy, acid soils, deficient in phosphorus (P) which severely limits its production. Because processed phosphate fertilizers are expensive and poorly available to farmers, rock phosphate is viewed as a cheap alternative phosphate source. The present study evaluated 696 U.S Core Collection and IITA cowpea accessions for adaptation to low soil P environments and for response to rock phosphate application. Subsequently, organic acid exudation by selected cowpea genotypes as a mechanism for P acquisition from Fe-oxide and Ca bound P was investigated. A low P soil from Nacogdoches pine forest was used to grow plants. There were two P treatments: 0 and 300 mg P/kg of soil as Tahoua (Niger) rock phosphate. At harvest, plant height, shoot and root dry weights were determined and total biomass and shoot-to-root ratios were computed. Shoot P contents of 100 selected accessions were measured. Sixteen accessions reflecting the wide array of responses observed were selected for the organic acid study. Plants were grown in a growth chamber hydroponically with no P and +P nutrient solutions for 3 weeks. Organic acids were collected in a CaCl2-KCl solution. The nature and quantity of the collected organic acids was determined. Cowpea accessions were significantly different in their ability to adapt to Pdeficiency stress and to acquire P from rock phosphate. The parameters most effective in separating the accessions were shoot mass and total biomass. This data will be potentially useful in the selection of cowpea germplasm for (1) adaptation to West African soils of low P fertility, and (2) ability to utilize P from poorly soluble rock phosphate. The predominant organic acid exuded by cowpea roots was a tricarboxylic acid not yet identified. There was surprisingly more exudation of this acid under +P than under –P conditions. Exudation was more highly correlated to roots than to shoots.
8

Genetic Diversity Of Scald (rhynchosporium Secalis) Disease Resistant And Sensitive Turkish Barley Seed Sources As Determined With Simple Sequence Repeats

Dizkirici, Ayten 01 August 2006 (has links) (PDF)
Scald disease (Rhynchosporium secalis) is one of the major plant diseases causing considerable yield loss in barley (Hordeum vulgare) plantations in Turkey. To develop, scald resistant barley varieties, C.R.I.F.C. of Turkey has a large accumulated collection of barley seed sources in hand, but these samples are difficult to be followed and used in the breeding programs due to lack of genetic studies on them. Thus, the objective of this study was to characterize and fingerprint of eighty barley seed sources, and assess the magnitude and pattern of genetic diversity that could be used to have more efficient scald disease resistant breeding programs in the future. Forty scald disease resistant and 40 scald sensitive Turkish barley seed sources were screened using 6 simple sequence repeats (SSR) primers. Each of barley seed source were represented with four seeds, assuming they are genetically uniform since barley is a self-pollinated crop. Estimated genetic parameters indicated that scald disease resistant and sensitive barley seed sources still maintain large amount of genetic diversity. For example, expected heterozygosity was 0.62&plusmn / 0.01 and 0.64&plusmn / 0.01 for resistant and sensitive Turkish barley seed sources, respectively. Thirty-nine percent of total genetic variation was between populations for resistant and 46% for sensitive group, while 61% of total variation was within populations for resistant group and 54% for sensitive group. When overall Turkish barley seed sources were considered, genetic distances between scald sensitive seed source S18 and resistant R1 as well as between sensitive S28 and resistant R1 were large. Scald resistant and sensitive barley seed sources were generally located in different clusters in dendrogram. The presence of R25, R39 and S16 barley seed sources with high genetic diversity parameters among studied seed sources, suggests that this diversity could be important drive in future barley breeding program in Turkey. However, further study is needed to illustrate genetic divergence of Turkish barley seed sources with use of more molecular markers.
9

Reação de genótipos de Capsicum annuum a nematoides de galha / Reaction of Capsicum annuum genotypes to root-knot nematodes

Soares, Renato Silva [UNESP] 21 February 2017 (has links)
Submitted by RENATO SILVA SOARES null (renato_2366@hotmail.com) on 2017-04-16T22:48:52Z No. of bitstreams: 1 Dissertação Renato Final.pdf: 1678992 bytes, checksum: 1f1da592f1239dc378237df3f8910585 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-18T17:49:50Z (GMT) No. of bitstreams: 1 soares_rs_me_jabo.pdf: 1678992 bytes, checksum: 1f1da592f1239dc378237df3f8910585 (MD5) / Made available in DSpace on 2017-04-18T17:49:50Z (GMT). No. of bitstreams: 1 soares_rs_me_jabo.pdf: 1678992 bytes, checksum: 1f1da592f1239dc378237df3f8910585 (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O pimentão (Capsicum annuum L.) apresenta grande importância socioeconômica, estando entre as dez hortaliças mais consumidas no Brasil. O cultivo dessa olerácea em ambiente protegido tem aumentado de forma significativa no decorrer dos anos. Entretanto, o cultivo intensivo nesse sistema tem causado aumento da incidência de nematoides de galha (Meloidogyne spp.). Uma forma de manejar esses fitoparasitas na cultura é o uso de cultivares ou porta-enxertos com resistência às principais espécies. O presente trabalho teve por objetivo avaliar a reação de genótipos de C. annuum quanto à resistência múltipla à Meloidogyne incognita raça 3, Meloidogyne javanica e Meloidogyne enterolobii. Por motivo de logística, o trabalho foi realizado em três experimentos, utilizando o delineamento inteiramente casualizado, sendo o primeiro em esquema fatorial 31 x 3 (27 genótipos de C. annuum, as cultivares de pimenta BRS Moema e BRS Mari, uma linhagem de C. frutescens e o tomateiro ‘Santa Cruz Kada’) e três espécies de nematoides (M. incognita raça 3, M. javanica e M. enterolobii), o segundo em esquema fatorial 39 x 3 (36 acessos de C. annuum, duas cultivares de pimenta utilizadas no primeiro experimento e o tomateiro ‘Santa Cruz Kada’) e as três espécies de nematoides mencionadas anteriormente, e o terceiro experimento em fatorial 27 x 3, sendo 24 genótipos de C. annuum, as cultivares de pimenta BRS Moema e de pimentão Ikeda, o tomateiro ‘Santa Cruz Kada’ e as três espécies de nematoides de galhas utilizadas nos experimentos 1 e 2. No ato do transplantio, as mudas foram inoculadas com 5.000 ovos e juvenis de segundo estádio de cada espécie de nematoide, separadamente. Considerou-se uma planta por vaso como uma repetição. A avaliação dos genótipos, em ambos os experimentos, ocorreu aos 90 dias após a inoculação. Avaliaram-se o número total de ovos e juvenis de segundo estádio (NTOJ), o número de ovos e juvenis de segundo estádio por grama de raiz (NOJGR), o índice de reprodução (IR) e o fator de reprodução (FR). Os dados foram submetidos à análise de variância, e quando identificadas diferenças significativas pelo teste F, foram agrupadas pelo teste de Scott-Knott, a 5% de probabilidade. Os genótipos de C. annuum CNPH 146, CNPH 185, CNPH 187, CNPH 698, CNPH 671, CNPH 672, CNPH 680, CNPH 717 e CNPH 718 foram classificados como resistentes e muito resistentes pelo fator de reprodução e índice de reprodução, respectivamente, a M. incognita raça 3 e M. javanica; no entanto, estes e os demais genótipos foram suscetíveis a M. enterolobii, pelo FR. Os acessos CNPH 47, CNPH 640, CNPH 677, CNPH 684, CNPH 690 e CNPH 693 foram classificados como ligeiramente resistentes a M. enterolobii, pelo IR. Utilizando o fator de reprodução como metodologia de seleção, não houve genótipos de C. annuum com resistência múltipla a M. incognita raça 3, M. javanica e M. enterolobii. / The sweet pepper (Capsicum annuum L.) presents great socioeconomic importance, being among the ten vegetables most consumed in Brazil. The cultivation of this crop in protected environment has increased significantly over the years. However, the intensive cultivation in this system has caused an increase in the incidence of root-knot nematodes (Meloidogyne spp.). One way to manage these phytoparasites in the crop is the use of cultivars or rootstocks with resistance to the main species. The objective of the present work was to evaluate the reaction of Capsicum annuum genotypes for multiple resistance to Meloidogyne incognita race 3, Meloidogyne javanica and Meloidogyne enterolobii. For reasons of logistics, the work was carried out in three experiments using a completely randomized design; the first one in a factorial scheme 31 x 3 (27 genotypes of C. annuum, the cultivars of pepper BRS Moema and BRS Mari, a line of C. frutescens and the tomato ‘Santa Cruz Kada’) and three nematode species (M. incognita race 3, M. javanica and M. enterolobii); the second in a 39 x 3 factorial scheme (36 accessions of C. annuum, the two pepper cultivars used in the first experiment and the tomato ‘Santa Cruz Kada’) and the three nematode species mentioned above; and the third experiment in factorial 27 x 3, being 24 genotypes of C. annuum, the cultivars of pepper BRS Moema and of sweet pepper Ikeda, the tomato 'Santa Cruz Kada' and the three species of nematodes used in experiments 1 and 2. After the transplanting, the seedlings were inoculated with 5000 eggs and second-stage juveniles of each nematode species separately. One plant per pot was considered as a repetition. The evaluation of genotypes in both experiments occurred at 90 days after inoculation. The total number of eggs and second-stage juveniles (NTOJ), number of eggs and second-stage juveniles per gram of root (NOJGR), reproduction index (IR) and reproduction factor (RF) were evaluated. Data were submitted to analysis of variance, and when significant differences were identified by the F test, were grouped by the Scott-Knott test at 5% probability. The genotypes of C. annuum CNPH 146, CNPH 185, CNPH 187, CNPH 698, CNPH 671, CNPH 672, CNPH 680, CNPH 717 and CNPH 718 were classified as resistant and very resistant by the reproduction factor and reproduction index, respectively, to M. incognita race 3 and M. javanica, however, these and the other genotypes were susceptible to M. enterolobii, by RF. The accessions CNPH 47, CNPH 640, CNPH 677, CNPH 684, CNPH 690 and CNPH 693 were classified as slightly resistant to M. enterolobii by IR. Using the reproduction factor as a selection methodology, there were no C. annuum genotypes with multiple resistance to M. incognita race 3, M. javanica and M. enterolobii.
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Resistência de genótipos de meloeiro à mosca-minadora Liriomyza sativae (Blanchard, 1938) (Diptera: Agromyzidae) / Resistance of melon genotypes to the leafminer Liriomyza sativae (Blanchard, 1938) (Diptera: Agromyzidae)

Marcos Aurélio Araujo Lima 03 July 2012 (has links)
Atualmente, a mosca-minadora Liriomyza sativae (Diptera: Agromyzidae) é uma das principais pragas da cultura do meloeiro no Brasil. É comumente relatado que as moscas-minadoras se tornam pragas devido a um desequilíbrio biológico provocado pelo uso incorreto de inseticidas além do seu grande potencial biótico. Portanto, é fundamental que sejam desenvolvidas estratégias de manejo que atuem em equilíbrio com o ambiente. Assim, a resistência de plantas a insetos assume papel fundamental nesse contexto. Diante desses fatos, a presente pesquisa objetivou avaliar a resistência de genótipos de meloeiro à mosca-minadora. A criação do inseto foi mantida em plantas de feijão-caupi. Foram realizados ensaios preliminares com diferentes números de casais e diferentes tempos de exposição das plantas aos insetos visando determinar a combinação mais adequada para estudos de resistência. Os resultados indicaram que são necessários quatro casais/planta e um tempo mínimo de infestação de 24 horas. Foram testados inicialmente 44 genótipos divididos em cinco grupos, comparados sempre a uma testemunha suscetível (Vereda). Cada grupo foi mantido numa gaiola onde ocorreu a infestação pelos adultos. Após cinco dias, foi avaliado o número de minas por planta, com base no que foi calculado o Índice de Resistência. A partir desse índice, foram selecionados, os oito genótipos mais promissores (os acessos A5, A15, A22, A29, A42 e A44 e as cultivares Mc Laren e Guaporé) para avaliação dos possíveis tipos de resistência envolvidos. No teste de antixenose para oviposição, constatouse que, no teste de livre escolha, todos os genótipos foram menos preferidos para oviposição que a testemunha, enquanto no teste de confinamento os menos preferidos foram os genótipos A5, A22, A29, A42, A44 e Guaporé. Os genótipos A22, A29, A42, A44 e Mc Laren prolongaram a duração do período embrionário do inseto, enquanto a cultivar Guaporé provocou sobrevivência larval nula e Mc Laren prolongou a fase larval e, juntamente com o acesso A44, reduziu a sobrevivência dessa fase. Por outro lado, o acesso A15 foi o que proporcionou a maior duração da fase de pupa, sendo o tamanho pupal reduzido pelos acessos A29, A42 e A44. A maior duração da fase imatura do inseto ocorreu nos genótipos A29 e Mc Laren. Os diferentes genótipos de meloeiro não influenciaram a longevidade, a razão sexual, os períodos de pré-oviposição e de oviposição e a fecundidade total dos adultos de L. sativae. Com base na avaliação do efeito dos genótipos sobre a biologia do inseto, constatou-se que Mc Laren, Guaporé, A22, A29, A42 e A44 apresentam resistência do tipo antibiose e/ou antixenose para alimentação. No ensaio de tolerância, concluiu-se que a quantidade de clorofila nas folhas foi um parâmetro adequado para caracterizar o efeito do ataque de L. sativae sobre o meloeiro; por outro lado, os pesos de matéria fresca e seca e o comprimento do ramo principal não foram parâmetros adequados para avaliação da tolerância. Considerando todos os parâmetros estudados nesse ensaio, os genótipos A44 e Guaporé se comportaram como tolerantes. / Nowadays, the vegetable leafminer Liriomyza sativae (Blanchard) (Diptera: Agromyzidae) is one of the major melon pests in Brazil. The outbreak of this pest has been frequently reported to be due to biological control disruptions caused by the incorrect use of insecticides and to its high biotic potential. Therefore, it is important that management strategies acting in balance with the environment are developed. Studies on host plant resistance to insects play a fundamental role in this context. In this research project, we intended to evaluate the resistance of melon genotypes to the vegetable leafminer. The insect population was reared under laboratory conditions on bean plants. Preliminary assays were carried out with different numbers of couples and different infestation times aiming to find the most adequate combination to be used in plant resistance studies. The best results were obtained with four couples per plant and 24 hours of infestation. Initially, 44 melon genotypes were screened in five groups of nine genotypes compared to a susceptible control genotype (Vereda). Each group was placed in one cage for infestation with adult leafminer flies. After four days, the mean number of mines per plant was evaluated. Based on this data, the Resistance Index was estimated and eight genotypes were selected (accessions A5, A15, A22, A29, A42 and A44 and cultivars Mc Laren and Guapore). In the oviposition preference study, all genotypes were less preferred than the control in the multiple-choice test while in the no-choice test genotypes A5, A22, A29, A42, A44 and Guaporé was less preferred. Egg duration was longer in genotypes A22, A29, A42, A44 and Mc Laren than in control. In Guapore no larvae survived while in A44 and Mc Laren larval survival was smaller than in control, moreover in Mc Laren larval duration was longer than in control. Accession A15 provided the longest pupal duration, while accessions A29, A42 and A44 presented the smallest pupal sizes. In genotypes A29 and Mc Laren the egg-adult period was longer than the control. The different genotypes did not affect longevity, sex ratio, preoviposition and oviposition periods and fecundity of females. Based on the evaluation of host plant effect on the vegetable leafminers biology it was established that the genotypes A22, A29, A42, A44, Mc Laren and Guapore present resistance by antibiosis and/or antixenosis for feeding. In the tolerance test, it was concluded that chlorophyll content was an adequate parameter for discriminating the genotypes in relation to attack by L. sativae; on the other hand, main branch length and fresh and dry weight were not adequate parameters for tolerance study. Based on all parameters evaluated, genotypes A44 and Guapore seems to be tolerant.

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