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Dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa / In the forestry industry the requirement for the maintenance of a broad genetic base is integral to the success of breeding programmes such as those for Eucalyptus grandis, an important species to the South African forestry industry. Plant cryopreservation is an economical option to maintain such a genetic base, as it allows storage of vegetative materials at sub-zero temperatures, while maintaining juvenility. However, successful cryopreservation of this sub-tropical species has been restricted by its sensitivity to cryopreparative drying. As a consequence, the viability of material is reduced even before reaching the freezing stage. Despite this abiotic stress restriction, evidence of upstream ‘cross-talk’ implying downstream ‘cross-tolerance’ has suggested the possibility that cold acclimation may improve the tolerance responses towards dehydration stress by means of ‘cross-acclimation’. It was therefore the aim of the study to understand some of the physiological and biochemical responses of in vitro E. grandis shoots to different non-freezing low (chilling) temperatures and exposure periods, and to establish an appropriate ‘cross-acclimation’ regime for the physical drying pre-treatment. E. grandis shoot clusters (4-8 leaves and 2-5 axillary buds) were exposed to the chilling temperatures of 5°C, 10°C or 15°C for 1 or 3 days. The physiological and biochemical responses were evaluated, and thereafter the appropriate cold acclimation (or ‘cross-acclimation’) regime selected. The appropriate physical drying time was also selected for shoot clusters according to their physiological responses. When the appropriate regimes had been determined, the physiological and biochemical responses of shoot clusters treated consecutively to cold acclimation and then physical drying were evaluated. The physiological responses evaluated were water content, viability, and vigour (i.e. the number of visible axillary buds and shoots produced over 2 weeks). The biochemical responses measured were the concentrations of: 1) total soluble sugars, 2) starch, 3) phenolic acid, and 4) superoxide. The data suggested that the appropriate cold acclimation regime was treatment at 10°C for 3 days. This was based on the accumulation of the high levels of phenolic acid (3.05 ± 0.09 mg GAE.g-1 FWS) and positive vigour responses (11.90 ± 0.60 visible axillary buds/week and 3.10 ± 0.20 visible shoots/week), compared with the other chilling temperature treatments. The appropriate drying time selected for shoot clusters was 80 min over activated silica gel to achieve a water content of 0.32 ± 0.04 g water.g-1 FWS. In the dried material there were high levels of soluble sugars (47.65 ± 1.90% of the fresh weight of shoots) and unknown components that accounted for 48.10 ± 1.86% of the fresh weight, followed by phenolic acid (3.09 ± 0.05%) and proline (0.490 ± 0.011%). Despite these measured responses, viability of the shoots was impacted by drying, dropping to 88.9 ± 3.9%. When shoot clusters were pre-treated at 10°C for 3 days and then physically dried, viability of all (100%) the material was retained and the water content did not drop as low as with physical drying alone, dropping to 0.52 ± 0.05 g water.g-1 FWS. The biochemical responses showed that tolerance was strongly dependent on a high proportion of soluble sugars (83.66 ± 1.48% of the fresh weight of shoots) and phenolic acid (3.77 ± 0.12%), followed by proline (0.406 ± 0.018%). The study had confirmed that ‘cross-acclimation’ through means of cold acclimation (chilling pre-treatment at 10°C for 3 days) can induce ‘cross-tolerance’ towards physical drying, where osmotic adjustments and osmoprotection appeared to have been improved. It is therefore possible that this may have the potential to improve survival during the latter stages of the cryopreservation procedure, despite the higher retention of water in shoot clusters after drying.

O Brasil é um dos maiores produtores de polpa de eucalipto e suas plantações são dependentes do enraizamento adventício de genótipos selecionados. Neste trabalho foram analisados os efeitos de diferentes fontes de carboidratos e de qualidade de luz no enraizamento adventício in vitro de duas espécies de eucalipto economicamente importantes, Eucalyptus grandis, de fácil enraizamento e Eucalyptus globulus, recalcitrante ao enraizamento. As fontes de carboidratos testadas em meio de cultura líquido foram sacarose, glicose e frutose. Microestacas de ambas as espécies e plantas-matrizes de Eucalyptus globulus foram expostas a comprimentos de onda enriquecidos para luz branca, azul, vermelha e vermelho-extrema e seus efeitos foram testados em relação ao enraizamento. O enraizamento adventício aumentou em ambas as espécies quando foi fornecida sacarose durante a fase de indução e frutose na fase de formação. Fazendo uma analogia entre o enraizamento adventício e a tuberização de batata, este resultado pode ser atribuído a atividade de invertases na fase de indução e fructoquinase na fase de formação, porém mais estudos devem ser conduzidos para confirmar esta hipótese. Não houve efeito de qualidade de luz no enraizamento adventício quando os tratamentos de luz foram aplicados nas microestacas. A exposição de plantas-matrizes crescidas em meio de cultura sem sacarose à ambiente enriquecido com comprimento de onda vermelho-extremo proporcionou um aumento de 255% na porcentagem de enraizamento de suas microestacas, mesmo na ausência de auxina exógena no meio de enraizamento, quando comparado com plantas-matrizes expostas à luz branca nas mesmas condições de cultura. Este resultado está aparentemente relacionado com o balanço 8 endógeno de açúcares solúveis e amido na parte aérea e raízes em desenvolvimento, com maior conteúdo de ambos na região das raízes. / Brazil is one of the largest producers of eucalypt pulp and its plantations are dependent of adventitious rooting of selected genotypes. In this work we analyzed the effects of different carbohydrate sources and light qualities on in vitro adventitious rooting of two economically important eucalypt species, the easy-to-root Eucalyptus grandis and the recalcitrant Eucalyptus globulus. The carbohydrate sources tested in static liquid medium were sucrose, glucose and fructose. The effect of white, blue, red and far-red light exposure on microcuttings of both species and on donor-plants of E. globulus was evaluated in relation to rooting. Rooting was improved in both species by supplying sucrose in the induction phase and fructose in the formation phase. By a putative analogy of adventitious rooting with tuberization in potato stems, this result was attributed to activities of invertases in the induction phase and fructokinase in the formation phase, but more studies will be needed to confirm this hypothesis. There was no effect of light quality on adventitious rooting when light treatments were applied on microcuttings. Compared to the white light-treated control donor-plants grown on medium without sucrose, donor-plants grown under a far-red light enriched environment on medium devoid of sucrose yielded 255% in the rooting percentage of microcuttings derived therefrom, even in the absence of exogenous auxin in rooting medium. This result was apparently related to the balance between endogenous hexoses and starch content in shoots and developing roots, with a higher content of both in the rooting zone.

O eucalipto é a arbórea mais cultivada no mundo para a exploração comercial de madeira. No Brasil, a principal espécie do gênero Eucalyptus utilizada é E. grandis, cujo cultivo, principalmente de híbridos com outras espécies, é voltado para a produção de celulose e papel. A relevância econômica do eucalipto para o Brasil e para vários países do mundo tem estimulado avanços científicos e tecnológicos, desde a área de biologia molecular até a silvicultura e a indústria de processamento da madeira. Entre os tópicos de interesse em biologia molecular estão genes e proteínas responsáveis pelo crescimento, pela qualidade da madeira e pela resposta vegetal a estresses ambientais. A família de proteínas Dof (DNA binding with one finger) compreende fatores de transcrição exclusivos de plantas, caracterizados pela presença do domínio Dof de ligação ao DNA, que contém uma estrutura semelhante ao domínio “dedo-de-zinco”. Esses fatores estão relacionados à ativação e à inibição de promotores de genes envolvidos nos mais variados fenômenos metabólicos das plantas tais como desenvolvimento do endosperma, metabolismo de carboidratos, germinação de sementes, desenvolvimento vascular e resposta a fitormônios. Pelo presente trabalho, visou-se caracterizar os fatores de transcrição Dof de E. grandis realizando-se análises filogenéticas com ferramentas de bioinformática, além de ensaios de RT-qPCR para se determinar perfis de expressão relativa dos genes Dof de E. grandis em folhas, caules e raízes de plantas sob diferentes tratamentos bióticos e abióticos que incluíram ABA, NAA, KIN, NaCl e seca. As análises filogenéticas permitiram a identificação de dez pares de genes parálogos no genoma de E. grandis, além de 13 grandes clados e nove pequenos grupos de genes ortólogos entre E. grandis, Arabidopsis thaliana e Populus trichocarpa. Os resultados permitiram-nos sugerir funções aos fatores de transcrição Dof de E. grandis. Os perfis de expressão relativa exibidos levaram-nos a concluir que os genes Dof são expressos em diversos órgãos e apresentam diferentes graus de acúmulo de mRNAs sob diferentes tratamentos. / Eucalypt is the most widely cultivated tree in the world for commercial logging. In Brazil, the main species of the Eucalyptus genus used is E. grandis, whose cultivation, mainly done with hybrids, is geared primarily for the production of pulp and paper. The economic relevance of eucalypts in Brazil and many countries worldwide has stimulated scientific and technological advances, from molecular biology to forestry and wood processing industry. Among the topics of interest in molecular biology are genes and proteins responsible for growth, the quality of wood and the plant response to environmental stress. The Dof (DNA binding with one finger) family of proteins comprehends plant exclusive transcription factors characterized by the presence of the DNA binding Dof domain, which is similar to the zinc finger domain. Dof transcription factors are related to the activation and inhibition of the promoters of genes involved in various plant metabolisms such as endosperm development, carbohydrate metabolism, seed germination, vascular development and response to phytohormones. In this study, we aimed to characterize the Dof transcription factors of E. grandis through phylogenetic analyzes using bioinformatic tools, in addition to RT-qPCR assays to determine the relative expression profiles of E. grandis Dof genes in leaves, stalks and roots of plants under different biotic and abiotic treatments that included ABA, NAA, KIN, NaCl and drought. Phylogenetic analysis allowed the identification of 10 pairs of paralogous genes in the genome of E. grandis, in addition to 13 major clusters and 9 small groups of orthologous genes between E. grandis, Arabidopsis thaliana and Populus trichocarpa, which allowed us to suggest functions for the E. grandis Dof transcription factors. The relative expression profiles showed that the Dof genes are expressed in various organs and display different degrees of mRNA accumulation under different treatments.

This thesis examines the application of the heat pulse velocity technique (HPV) to plantation-grown Eucalyptus grandis in the Eastern Transvaal, South Africa. The work addresses the application of the technique per se and is ultimately focused on improving the prediction of the hydrological impact of afforestation, to assist in the equitable management of South Africa's limited water resources. The verification of the HPV technique on E. grandis against the cut-tree method showed that the technique accurately reflected the water uptake in four three-year-old trees and a sixteen-year-old tree. It was found that accurate measurement of wound size and probe separation was essential for accurate water use estimates. The optimal probe allocation strategy for accurate measurements of transpiration in individual trees and stands of trees was examined. Stratifying the depths of implanted probes resulted in greater precision and repeatability in the HPV-derived estimates of sap flow in E. grandis. Given a limitation in the number of probes available to estimate stand transpiration, the results showed that sampling many individuals with a low sampling intensity (few probes per tree), rather than sampling few individuals intensively, improved the estimate of stand transpiration. An examination of the influence of tree age and season on transpiration rates showed that the transpiration rate per unit leaf area of E. grandis declined with age. Also, transpiration rates were higher in summer than under equivalent conditions of evaporative demand in winter. A seasonal change in the response of transpiration to VPD was implicated as the primary cause of this shift. A number of models were derived to predict transpiration from E. grandis. The variables vapour pressure deficit (VPO) and photosynthetically active radiation (PAR) were found to account for a large proportion of the observed variation in transpiration from the age sequence of trees studied. The models developed are applicable to trees of varying age, but are valid only for conditions where minimal soil water stress is experienced. The derived models were tested against two sets of independent data. This confirmed that a simple linear multiple regression adequately describes the relationship between transpiration and the two driving meteorological variables, PAR and VPO, in E. grandis. The application of a selection of the developed models on a sample data set from Sabie showed that transpiration from a three-year-old stand of E. grandis in summer may be more than double that for a sixteen-year-old stand under the same conditions. Simulated results also showed that transpiration in summer was about 25 to 50% higher than that from the same stand during winter conditions. Simulated transpiration rates from the young E. grandis stands were high, suggesting that further validation of the estimated rates is required before the models are applied. It is concluded that the HPV method is an ideal technique to estimate water use in E. grandis trees. The models developed represent a major advancement on previous models used to predict the hydrological impact of afforestation on mountain catchments. / Thesis-(Ph.D.)-University of Natal, Durban, 1994.

Clonal propagation of Eucalyptus spp. and its hybrids allows for competitiveness in the commercial forestry industry through the propagation and preservation of superior/elite genotypes. Vegetative propagation through rooted cuttings is the industry‟s standard and the choice of clones selected for plantations are determined by their rooting ability. However, as many potentially valuable genotypes are recalcitrant to adventitious rooting, micropropagation is the only effective means of propagating them. Micropropagation results in high plantlet yields, achieved primarily through the empirical use of the key plant growth regulators (PGRs) cytokinins and auxins, for shoot and root production, respectively. Their selection for use in vitro is driven by their effects on percent rooting rather than root quality. Little is known regarding the quality of the roots of the plantlets ex vitro, but there is some evidence that they are different from those of seedlings and cuttings. It was therefore hypothesized that the properties of exogenous PGRs and their interaction with other exogenous and endogenous PGRs, influenced root development and subsequent root quality. This was tested in vitro using a good-rooting E. grandis (TAG31) and two poor-rooting E. grandis x nitens hybrid clones (GN155 and NH58). In the former, the auxins supplied during the pre-rooting culture stages (multiplication and elongation) were sufficient for 100% rooting in an auxin-free rooting medium. Different combinations of PGRs in the two pre-rooting stages, followed by rooting without auxins, revealed a direct relationship between the stability of the supplied auxin and the rooting ability of TAG31. Gas chromatographymass spectrometry (GC-MS) analyses indicated that endogenous shoot levels of indole- 3-acetic acid (IAA) influenced graviperception. Also, low IAA content was associated with atypical starch grain accumulation or its absence from root tips (53.1 nmol IAA gˉ¹ DW compared with 325.7 nmol IAA g-¹ DW in gravisensing roots). The specific roles of the natural auxins IAA and IBA on root morphogenesis were then investigated using 2,3,5-triiodobenzoic acid (TIBA; inhibits IAA transport), ρ-chlorophenoxyisobutyric acid (PCIB; inhibits auxin signal transduction), and the auxin antagonist kinetin in the rooting medium, following root induction. After 3 weeks, the mean root diameter was significantly reduced from 552.8μm (control) to 129.2μm (with PCIB) and 278.6μm (with kinetin). TIBA increased root diameter to 833.4μm, decreased Δ root length, increased root vasculature and resulted in agravitropism. Hence, whereas rooting could be induced by IBA, IAA was necessary for the maintenance of vascular integrity and graviperception. This critical role of IAA in root development is of importance as IBA, owing to its higher stability, has been traditionally relied upon for root induction in the majority of micropropagation protocols. The potential of incorporating IAA into the media formulations of in vitro protocols for poor-rooters that do not respond well to IAA was then investigated, using GN155 and NH58. While PCIB in the rooting medium of GN155 completely inhibited rooting, the addition of dihydroxyacetophenone (DHAP), an inhibitor of auxin conjugation, to the rooting medium, did not significantly increase % rooting in the presence of 0.1 mg 1ˉ¹ IBA (i.e. 50% rooting with 2mM DHAP and IBA, compared with 45% with IBA alone). The results suggested that the inability of some eucalypts to induce roots easily in vitro was not due to a deficiency in auxin signal transduction or to auxin conjugation. Instead, rooting was inhibited by an accumulation of kinetin within shoots during the pre-rooting culture stages. The endogenous levels of PGRs in shoots of GN155 and NH58 showed a strong relationship (R² = 0.943) between the shoot kinetin:auxin and shoot rootability. Substituting kinetin with the relatively less stable natural cytokinin trans-zeatin in the elongation stage resulted in a significant increase in % rooting in both clones, from 19% to 45% (GN155) and from 31% to 52% (NH58), with 0.1 mg 1ˉ¹ IAA in the rooting medium. However, omitting all cytokinins from the elongation medium, resulted in over 95% and 75% rooting of shoots of GN155 and NH58, respectively, with 0.1 mg 1ˉ¹ IAA. These results suggest that IAA is a requirement for root development and cannot be substituted by its analogues in certain root developmental events. Hence, IAA should be the preferred auxin for eucalypt micropropagation. As fundamental research, the approach taken in this study circumvents the empirical method used in improving micropropagation protocols. The importance of the properties and the interactions between endogenous and exogenous PGRs in regulating root morphogenesis, and the practical implications of these findings is emphasised. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

No presente trabalho está descrita a análise de experimentos de microarranjos de DNA realizados pelos pesquisadores do Projeto GENOLYPTUS em conjunto com a empresa NimbleGen Systems Inc. (Reykjavik, Iceland), assim como a validação dos resultados gerados por essa análise, com a finalidade de encontrar genes diferencialmente expressos entre folhas e xilema de E. grandis para futuro estudo. O processo de análise dos microarranjos de DNA envolveu a busca por um software com programas estatísticos adequados ao estudo de grande quantidade de dados com mínima probabilidade de erro. A comprovação dos resultados gerados pelo software escolhido foi realizada com o uso da técnica da reação em cadeia da DNA-polimerase quantitativa (em tempo real) precedida de transcrição reversa (qRT-PCR). Alguns dos genes mais diferencialmente expressos foram selecionados para esta etapa, juntamente com alguns genes com expressão não tão alta. Os genes mais expressos nas folhas que foram escolhidos codificam para; (i) uma proteína semelhante à metalotioneína do tipo 3 (MT-3); (ii) uma glicolato-oxidase; (iii) uma catalase; (iv) uma fosforribulocinase precursora de cloroplasto (PRK); (v) um fator de transcrição MYB do tipo MYB142 e, (vi) uma proteína tipo “dedo-de-zinco”. Os genes mais expressos no xilema escolhidos foram os que codificam (i e ii) duas proteínas expressas em Arabidopsis thaliana; (iii) uma proteína hipotética expressa em Nicotiana benthamiana; (iv) uma descarboxilase de UDPglicuronato do tipo 2, (v) uma quitinase do tipo ELP; (vi) uma celulosesintase tipo 3; (vii) um fator de transcrição MYB; (viii) uma cafeoil-CoA-3- O-metiltransferase (CCoAOMT) e; (ix) uma proteína rica em prolina híbrida do tipo 2 (HyPRP2). Os resultados das qRT-PCRs demonstraram que o experimento de microarranjo e seus resultados foram consistentes e válidos, embora os primeiros tenham demonstrado valores de expressão freqüentemente mais altos. Acreditamos que tanto a análise dos microarranjos de DNA quanto a equivalência das amostras (duplicatas) biológicas estudadas foram totalmente sustentadas pelos resultados da qRT-PCR, pois foram robustas o suficiente para estimar um grande número de genes simultaneamente e indicar aqueles mais importantes como candidatos para futuras análises. / In the present work it is described the analysis of DNA microarray experiments developed by GENOLYPTUS researchers together with Nimblegen Systems Inc. (Reykjavik, Iceland), as well as the validation of the generated results with the aim to find differentially expressed genes between leaves and xylem tissue of E. grandis for further study. The DNA microarray analysis process comprised the search for software containing statistical programs satisfactory for studying an enormous amount of data with a very low false discovery rate. The confirmation of the generated data by the chosen software was made with the use of quantitative (real-time) reverse-transcription followed by polymerase chain reaction (qRT-PCR). Some of the most differentially expressed genes were selected for this step, along with some genes with average expression. Leaf chosen genes were those that codify (i) a metallothionein-like protein type 3 (MT-3), (ii) a glycolate oxidase, (iii) a catalase, (iv) a precursor phosphoribulokinase (PRK) from chloroplast, (v) a MYB transcription factor (MYB142), and (vi) a CONSTANS-LIKE 16 zincfinger protein. Xylem chosen genes were those codifying (i and ii) two expressed proteins from Arabidopsis thaliana, (iii) a hypothetic protein expressed in Nicotiana benthamiana, (iv) a putative UDP-glucuronate decarboxylase type 2, (v) a chitinase type ELP (ectopic deposition of lignin in pith), (vi) a cellulose synthase type 3, (vii) a MYB transcription factor, (viii) a caffeoyl-CoA 3-O-methyltransferase (CCoAOMT), and (ix) a hybrid proline-rich protein type 2 (HyPRP2). Our qRT-PCR results proved the full consistency and validation of the microarray experiments, although the relative expression ratios of the first were often higher. We believe that our microarray analysis as well as the equivalence of biological samples (duplicates) were fully supported by the qRT-PCR findings since they were robust enough to evaluate a massive number of genes and able to point out important candidate genes.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-03-30T18:08:15Z No. of bitstreams: 1 texto completo.pdf: 497483 bytes, checksum: 799187a8040ab486030824a44f88bfca (MD5) / Made available in DSpace on 2017-03-30T18:08:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 497483 bytes, checksum: 799187a8040ab486030824a44f88bfca (MD5) Previous issue date: 2003-10-30 / O gênero Eucalyptus é o mais freqüente entre as árvores plantadas no Brasil. Sabendo-se que os besouros desfolhadores são as mais importantes pragas em florestas de eucaliptos em vários países e, que a principal espécie de besouro desfolhador de eucaliptos no Brasil é Costalimaita ferruginea (Fabr.) (Coleoptera: Chrysomelidae). Tornou-se necessário conhecer com mais detalhes o comportamento daninho desta espécie, bem como as conseqüências do seu ataque às árvores de eucalipto. Para tanto foram identificadas quatro intensidades de ataque do besouro C. ferruginea, em plantio de Eucalyptus grandis, com idade entre 7 e 9 meses, e avaliadas as conseqüências deste ataque, durante o ciclo desta floresta, até a época de corte (sete anos). As árvores foram avaliadas quanto ao seu crescimento, produção de madeira, formato do fuste e sobrevivência. A descrição da ocorrência foi feita por meio do uso do sistema de monitoramento da praga, em uso no local. Para conhecer as conseqüências do ataque da praga sobre o povoamento florestal, nove medições foram realizadas entre os 12 e 84 meses de idade da floresta, sendo a sobrevivência das árvores quantificada nestas ocasiões. Aos 84 meses foi feita a cubagem rigorosa de árvores, segundo as quatro intensidades de ataque avaliadas para verificar as conseqüências do ataque na forma do fuste das árvores. Os dados das variáveis de interesse, que foram: diâmetro a 1,3 m de altura (dap); altura (Ht); área basal (B); volume de madeira por hectare (V); relação hipsométrica (Ht x dap); forma do fuste (taper); e sobrevivência das árvores, foram submetidos a análises de regressão. De posse das equações ajustadas para cada variável de interesse, procedeu-se um teste de identidade de modelos, que comparou, para cada variável, as diferentes intensidades de ataque causado pela praga às árvores com a testemunha. Verificou-se que todas as variáveis estudadas foram negativamente alteradas, de forma significativa, por todas as intensidades de ataque da praga, causando efeitos indesejáveis, tanto para as árvores como para o povoamento, gerando informações de fundamental importância na prática do manejo integrado deste importante grupo de pragas florestais, os besouros desfolhadores. / The eucalyptus species has been the most cultivated tree in Brazil and the leaf- beetles have been the most important pests in eucalyptus forests in some countries. The main species of eucalyptus leaf-eating beetles is Costalimaita ferruginea (Fabr.) (Coleoptera: Chrysomelidae) and it is necessary to know more details about the harmful behavior of this specie, as well as the consequences of its attack on eucalyptus trees. For this reason, four attack intensities of C. ferruginea beetles in Eucalyptus grandis plantation in the age between 7 and 9 months were identified and their consequences during the forest cycle until the cut period (seven years) were evaluated. The trees were analyzed in relation to their growth, wood production, bole format and survival. The description of the occurrence was made through the pest monitoring system used in the place. In order to know the consequences of the pest attack in the forest stand, nine measurements were carried out when the forest was between 12 and 84 months and the survival of the trees was quantified in these periods. When the forest reached 84 months a rigorous tree scaling was made according to four evaluated intensities of attack to verify its consequences in the tree bole form. The data of the variable of interest, that were: diameter: 1,3 m high (dap); height (Ht); basal area (B); wood volume for hectare (V); hypsometric relation (Ht x dap); bole form (to taper); and the survival of the trees, were submitted to the regression analysis. Through these equations adjusted for each variable of interest, a model identity test was made. It compared for each variable the different intensities of attack caused by the pest to the trees with the control. It was verified that all the studied variables were modified in a negative and significant way for all the intensities of the pest attack causing an undesirable effect as for the trees as for the stand. The resulting information has a great importance for the integrated management practice and for this important group of forest pest: the leaf-beetles. / Não foram localizados o cpf e o currículo lattes do autor.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-04-19T18:16:28Z No. of bitstreams: 1 texto completo.pdf: 618763 bytes, checksum: 37ef3ce8cdc380b8c22164c1cbb50787 (MD5) / Made available in DSpace on 2017-04-19T18:16:28Z (GMT). No. of bitstreams: 1 texto completo.pdf: 618763 bytes, checksum: 37ef3ce8cdc380b8c22164c1cbb50787 (MD5) Previous issue date: 2002-02-07 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Clones de Eucalyptus grandis com resposta de resistência completa do tipo HR, imunidade, resistência parcial e suscetibilidade à ferrugem foram inoculados com o isolado I UFV -01 de P. psidii e avaliados sob microscopia de luz e microscopia eletrônica de transmissão. Observou-se maior desenvolvimento de hifas, haustórios e células-mãe do haustório (HMC) no clone suscetível (D UFV -1) que nos resistentes (D UFV -5, D UFV -3 e D UFV -4), havendo tendência de redução do número dos eventos citados com o nível de resistência. Em todos os clones, observou-se resposta celular de agregação de citoplasma e parede com intensidade de brilho, sendo mais pronunciada nos clones resistentes. Sob microscopia eletrônica de transmissão, esse desarranjo citoplasmático foi observado nos clones resistentes D UFV -5, D UFV -3. No clone com resposta de HR, encontraram-se haustórios totalmente encapsulados 144 horas após a inoculação (h.a.i.). No material imune D UFV -4 não foram observados haustórios, e nos clones suscetível e com resistência parcial os haustórios desenvolvidos foram lobados. A patogenicidade de 32 isolados de Puccinia psidii, obtidos de diferentes hospedeiras e regiões, foi avaliada em plantas da família Myrtaceae (goiabeira var. Paloma, jambeiro, jabuticabeira, eucalipto e pitangueira). A freqüência de isolados patogênicos a eucalipto, jambeiro, jabuticabeira, goiabeira e pitangueira foi de 100, 87, 81, 31 e 4%, respectivamente. A virulência de 21 desses isolados de P. psidii foi avaliada em oito clones de eucalipto e reconheceram-se três respostas diferenciais dentro da interação, as quais foram caracterizadas como raça 1, raça 2 e raça 3, com freqüência de 90,5, 4,8 e 4,8%, respectivamente. As raças 2 e 3 foram inoculadas nos clones diferenciadores e em um clone suscetível a ambos (D UFV -1) e quantificaram-se os componentes de agressividade. Determinou-se diariamente o número de lesões/folha (NLF) e o número de lesões esporulando (NLE); aos 12 dias da inoculação, foram quantificados o número de soros/pústula (NSP), o tamanho de uredínia (TU) e a produção de esporos/pústula (PEP). A área foliar total e doente foi determinada por meio do software QD - Quantificação de doenças de plantas. Estimaram-se a severidade da doença, a freqüência de infecção, a eficiência de infecção e a produção de esporos/lesão. Pela análise estatística, a interação clone x raça foi significativa para todas as variáveis citadas, exceto para FI. Detectou-se diferença estatística entre as raças 2 e 3 nos clones D UFV -3 e D UFV -1, para a produção de soros/pústulas e severidade da doença. Maior tendência foi observada para a raça 3 em todas as variáveis. O período infeccioso em todos os clones foi de 16 dias. Na raça 3 observou-se um pico de produção de esporos aos 12 dias com aproximadamente 5 x 10 3 urediniosporos/lesão/mL, que continuou constante até o final do período infeccioso, com uma média de seis a oito pústulas ainda produzindo esporos. A raça 2 apresentou maior variação na produção de esporos e, em média, 3 x 10 3 urediniosporos/lesão/mL foram produzidos, com mesma tendência nos dois clones avaliados. A variabilidade de P. psidii ficou evidenciada nas inoculações tanto da gama de hospedeiros dentro da família Myrtaceae quanto nos diferentes clones de eucalipto utilizados, nos quais foi possível diferenciar três raças de P. psidii. A comparação das duas raças de menor ocorrência (raças 2 e 3) demonstrou maior agressividade da raça 3 que a raça 2 no clone suscetível às duas raças. / Eucalyptus grandis clones with HR type complete resistance, immunity, partial resistance or susceptible response to rust were inoculated with IUFV-01 isolate of P. psidii and then evaluated by the use of light and transmission electron microscope. Development of hyphae, haustoria, haustoria mother cell (HMC) was greater in the susceptible clone (DUFV-1) compared to in the resistant clones (DUFV-5, DUFV-3 and DUFV-4). The number of event occurrence showed a decreasing tendency with increasing level of resistance. There was cytoplasm aggregation in all the clones, and the cell wall brilliance was greater in the resistant clones. Under electron microscope this cytoplasm disorder was observed in resistant clone (DUFV-5, DUFV 3). In clones with HR response, totally encapsulated haustorias were found 144h after inoculation (h.a.i.). While no haustoria were observed in the immune clone DUFV-4, lobed haustoria developed in the susceptible and partially resistant clones. The pathogenicity of 32 isolates of P. psidii, obtained from different hosts and regions was evaluated on plants of Myrtaceae family (guava var. paloma, jambo, jabuticaba, eucalyptus and pitanga). The frequency of isolates pathogenic on eucalyptus, jambo, jabuticaba and pitanga was 100, 87, 81, 31 and 4%, respectively. Virulence testing of 21 of these isolates on eight eucalyptus clones, showed three different interaction responses, which were characterized as race 1, race 2, and race 3, with the frequency of 90.5, 4.8 and 4.8% respectively. The components of aggressiveness of race 2 and 3 were quantified by inoculating the set differential clones and one clone (DUFV-1) susceptible to both the races. Number of lesions per leaf (NLF) and number of sporulating lesions (NSL) was quantified daily and the number of sori/pustule (NSP), the uredinia size (US) and the number of spores/pustule (NSP) was quantified 12 days after inoculation. The total and the diseased leaf area were estimated by the use of QD software - Quantification of Plant diseases. Disease severity, infection frequency, infection efficiency and the spore production/lesion were estimated. The interaction between clone x race was significant for all the variables except FI. The race 2 and 3 differed on clones DUFV-3 and DUFV-1, for the number of sori/pustule and disease severity, with greater tendency for race 3 in all the evaluated variable. The infectious period in all the clones was of 16 days. In the race 3 there was a peak in the spore production at 12 days with approximately 5 x 10 3 uredinospores/lesions/mL and remained constant till the end of the infectious period, while about 6 to 8 pustules still producing the spores. The race 2 showed a greater variation in the spore production with an average of 3 x 10 3 uredinospores/lesion/mL, on both the clones. The variability of P. psidii was evident in the inoculation of a range of the hosts in Myrtaceae family as well as on different clones of eucalyptus, which allowed for differentiation of three races of P. psidii. The comparison of the two less frequent races (race 2 and 3) showed greater aggressiveness of the race 3 on the two clones susceptible to both races. / Tese importada do Alexandria

Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-07-19T14:21:22Z No. of bitstreams: 1 texto completo.PDF: 590369 bytes, checksum: 219e17aaac516ca8a511236259bbff57 (MD5) / Made available in DSpace on 2017-07-19T14:21:22Z (GMT). No. of bitstreams: 1 texto completo.PDF: 590369 bytes, checksum: 219e17aaac516ca8a511236259bbff57 (MD5) Previous issue date: 2001-12-12 / Este experimento foi instalado no Viveiro de Pesquisas em Propagação de Plantas Lenhosas do Departamento de Engenharia Florestal da Universidade Federal de Viçosa, Viçosa, MG, em novembro de 2000, com o objetivo de estudar os parâmetros morfológicos e seus índices, determinados pelas suas relações, nas avaliações da qualidade de mudas de Eucalyptus grandis produzidas em diferentes tamanhos de tubetes e de dosagens de N - P - K. O substrato utilizado foi uma mistura de 80% de Composto Orgânico (CO) e de 20% de Moinha de Carvão (MC), adubados com a presença e ausência dos elementos N, P e K. Como embalagens foram utilizados 4 tamanhos de tubetes de plástico rígido com volumes de 50, 110, 200 e 280cm³, ficando acondicionados em bandejas de plástico rígido a 80cm de altura. O delineamento experimental foi o de blocos casualizados, disposto num arranjo fatorial com 32 tratamentos e três repetições. As análises estatísticas foram efetuadas com o objetivo de avaliar os parâmetros morfológicos e os índices resultantes de suas relações, assim como para verificar o agrupamento dos tratamentos, com base nos parâmetros de qualidade das mudas de Eucalyptus grandis avaliadas nas idades definidas, utilizando a distância generalizada de Mahalanobis e o método de Tocher. Em cada idade, independente das fertilizações, as médias das alturas e dos pesos de matérias secas, foram significativamente maiores, à medida que se aumentou o volume dos tubetes, provavelmente devido às considerações de nutrição e espaço para o crescimento radicular em maior volume de substrato. Os volumes dos tubetes devem ser considerados na produção de mudas de Eucalyptus grandis . Apesar de os maiores crescimentos terem sido nos maiores tubetes, esses não devem ser utilizados, uma vez que as alturas das mudas estão acima das tecnicamente ótimas para o plantio, além de o custo de produção ser onerado. Aos 60 dias de idade as mudas ainda estão pequenas e bastante tenras, sem o endurecimento adequado para o plantio no campo. Aos 120 dias após a semeadura o crescimento das raízes e da altura das mudas é afetado, mesmo nos tubetes de maiores volumes, não sendo essa a idade indicada. Após 90 dias de idade os volumes dos tubetes começam a restringir o crescimento das mudas, permitindo um maior crescimento diamétrico e uma maior produção de matéria seca. A adoção do diâmetro do coleto, da altura da parte aérea e da relação altura da parte aérea/diâmetro do coleto deve ser indicada na avaliação da qualidade de mudas de Eucalyptus grandis , aos 90 dias de idade e os tubetes de 50 e de 110 cm³, poderão ser utilizados, devido ao fato de que foram os parâmetros que apresentaram uma boa contribuição relativa, sem contudo ser um processo destrutivo, além de ser fácil as suas determinações. / Aiming at the study on morphologic parameters and their indices determined by their relations in evaluating the quality of Eucalyptus grandis seedlings produced in differents-sizes tubes and doses of N-P-K, an experiment was carried out on November 2000 at the "viveiro de pesquisas em propagação de plantas lenhosas" of the Forest Engineering Department in Universidade Federal de Viçosa, Viçosa-MG. A mixture of 80% organic compound (CO) and 20% charcoal powder fertilized with and without the elements N, P and K was used as substrate. Four sizes of hard plastic tubes at the volumes of 50, 110, 200 and 280 cm³ were arranged on hard plastic trays at 80cm height and used as wrappings. The randomized block experimental design was used at a factorial arrangement with 32 treatments and three replicates. The statistical analyses were performed to evaluate the morphological parameters and the indices resulting from their relationships, as well as to verify the grouping of the treatments based on the quality parameters of the Eucalyptus grandis seedlings evaluated at definite ages by using the Mahalanobis generalized distance and the Tocher method. Independently of fertilizations, at each age the averages of the heights and dry matter weights were significantly higher as the tube volumes were increased, which was probably due to considerations of the nutrition and space for root growth in a higher substrate volume. The tube volumes should also be considered in producing Eucalyptus grandis seedlings. Although the highest growths occurred in the larger tubes, these tubes should not be used because the seedling heights far surpass the ones considered as technically optimum to planting, besides higher production cost. At 60- day old, the seedlings are still small and quite tender, and do not present the hardness appropriate to field planting. At 120 days after sowing, the restriction to root growth and seedling height are affected even in the larger volume tubes, so this is not the indicated age. After 90-day old, the tube volumes begin to restrain the seedling growth, then allowing for a higher root collar diameter growth and a higher dry matter production. The adoption of the height of the aerial part, root collar diameter and height of the aerial part /root collar diameter relationship should be indicated to estimate the quality of the Eucalyptus grandis seedlings in the 50 and 110 cm³ volume tube when they were 90-day old might be used, since although presenting a satisfactory relative contribution besides being a nondestructive, easily determined and measured parameter.