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.

Eucalyptus spp. and hybrids dominate the global plantation forestry industry, and vegetative propagation through cuttings is the preferred method for their commercial use. However, the cuttings of some species and hybrids show recalcitrance to rooting. The first aim of this study was to improve percentage rooting of three clones of E. grandis x E. nitens (Clones 1, 2 and 3) identified by a commercial nursery as having variable rooting abilities. The second was to relate their rooting responses as cuttings to their rooting responses in vitro. Minicuttings (3.5 – 4 cm in length) (hereafter referred to as cuttings) were subjected to commercial nursery propagation practices. Initial results revealed that in the absence of exogenous plant growth regulators (PGRs), soft (juvenile, thin diameter) cuttings survived (87 – 95%) and rooted (29 – 32%) significantly better than hard (mature, thick diameter) ones (62 – 71% survival and 2 – 8% rooting). This validated the use of soft cuttings by the nursery and all subsequent studies were conducted with soft cuttings. The other nursery practice of applying the commercial rooting powder Seradix 2 (3 g kgˉ¹ indole-3-butyric acid [IBA]) adversely affected the survival and subsequent rooting of cuttings of Clones 1 and 2. Ensuing studies investigated: 1) the effect of mode of IBA application (powder vs. liquid); 2) concentrations of Seradix (0, 0.5, 1, 2 and 3 g kgˉ¹ IBA), applied at initial placement of cuttings and two weeks later; and 3) the influence of season on the survival and subsequent rooting of cuttings. Results showed that regardless of the mode of application, IBA significantly reduced percentage survival and rooting in cuttings of Clones 1 and 2. The delayed application of Seradix, two weeks after cuttings were initially set, resulted in a higher percentage survival and rooting than when cuttings were supplied with Seradix at initial placement. Nevertheless, the best survival for Clones 1, 2 and 3 (95%, 99% and 71%, respectively) and rooting (83%, 64% and 47%, respectively) occurred in the absence of Seradix. In addition, the survival and rooting of cuttings were seasonally variable, with particularly low rooting during winter (e.g. for Clone 1, 32%) when compared with summer (e.g. for Clone 1, 83%). Shoots from all the clones were multiplied in vitro, followed by elongation on either of two media (E1= kinetin, α-naphthalene acetic acid [NAA] and IBA; E2 = kinetin and indole-3-acetic acid [IAA]), and then rooting on 0, 0.1 or 1.0 mg 1ˉ¹ IBA. The latter were selected to typify the range of Seradix concentrations used for the cuttings (i.e. no IBA, low and high IBA concentrations). For all three clones, shoots elongated on E1 or E2 displayed high survival (> 80%) but failed to root without IBA in the rooting medium. For Clones 1, 2 and 3 the best in vitro survival (80%, 100% and 100%, respectively) and rooting (40%, 75% and 40%, respectively) occurred when shoots were elongated on E2 and rooted on 0.1 mg 1ˉ¹ IBA. However, 1.0 mg 1ˉ¹ IBA in the rooting medium severely inhibited survival (0 – 50%), irrespective of the clone or the elongation treatment used. Overall, cuttings demonstrated the best survival and rooting in the absence of exogenous IBA, which suggested that sufficient endogenous auxin was present within the shoots for successful root induction. The application of exogenous IBA may have disrupted the cuttings’ endogenous PGR balance resulting in an inhibition of survival and rooting. In vitro shoots required a low concentration of IBA (0.1 mg 1ˉ¹) in order to counteract the antagonistic effect of cytokinins that were supplied during the multiplication and elongation culture stages, and promote rhizogenesis. Essentially, both cuttings and in vitro shoots demonstrated adverse survival and rooting responses when subjected to excessively high IBA concentrations. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban 2013.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free State, 2013 / ntroduction: Good quality Eucalyptus is of importance to South Africa’s pulp and paper industry. Limited land is available for forestry, therefore Eucalyptus with genotypes for good pulp and paper qualities, particularly hybrids, are bred and cloned via cuttings. Although these Eucalyptus clones keep the favourable genotypes in the population, many have difficulty with rooting. Research has shown that rhizobacteria can improve rooting. Thus, one strategy to enhance the rooting of cuttings is to use rhizobacterial preparations. The aim of this study was to characterise rhizobacterial communities of Eucalyptus hybrid and species and identify possible plant-growth promoting rhizobacteria (PGPR). Materials and methods: Rhizospheric samples were collected from Eucalyptus hybrids and species. The rhizobacterial communities were characterised using fatty acid methyl esters (FAME) analysis and denaturing gradient gel electrophoresis (DGGE). DGGE fragments were further sequenced to identify rhizobacteria. Results and discussion: FAME analysis successfully achieved a broad characterisation of the Eucalyptus hybrid and species rhizobacterial communities based on their fatty acid composition. Myristic acid (C14:0) was the most abundant fatty acid. DGGE profiles gave a molecular profile of the Eucalyptus hybrid and species rhizobacterial communities based on their DNA composition. Nitrosomona eutropha was present in all samples which illustrates a nitrogen-rich environment. Adhaenbacter aquaticus was unique to the better rooting Eucalyptus hybrid GU111. Conclusion: This study provided some insight into the diversity of rhizobacterial communities of Eucalyptus hybrids and species. Possible PGPR were identified and the observation made that the nature of the soil environment changes with the aging of the associated host. These findings allow further investigation into the formulation of potential rhizobacterial preparations for rooting enhancement of Eucalyptus cuttings.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-03-03T20:59:22Z No. of bitstreams: 2 Dissertação - Rafael Tomaz Parreira - 2015.pdf: 4890640 bytes, checksum: 77343ad4266b8d39c9b9e142b0c167c3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-04T11:31:51Z (GMT) No. of bitstreams: 2 Dissertação - Rafael Tomaz Parreira - 2015.pdf: 4890640 bytes, checksum: 77343ad4266b8d39c9b9e142b0c167c3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-04T11:31:51Z (GMT). No. of bitstreams: 2 Dissertação - Rafael Tomaz Parreira - 2015.pdf: 4890640 bytes, checksum: 77343ad4266b8d39c9b9e142b0c167c3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-10-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Forest Inventory is a se to fimportanttechniquesthatprovidesessentialinformationsfor rationalandsustainableresourcesdrivinginforests. The selectedareacanbecharacteri- zedaboutspeciesquantityandquality.Forest inventories areusedinmanykindofstudies inorderofknowing,forecastingandevaluationinfields.Furthermore,theforestinven- toryalsoallowstoevaluatethetimberstockanditsviability,planningandpreparation ofexplorationtreestandsandpostexploratory.Anessentialinformationisthediameters alongoftreetrunkanditisindispensablefortimbervolume calculation.Currently,fordi- ametermeasuringahugetimeisrequiredandmanymistakesare possibledueinstruments defectsandhumanfailures.Somestudieshaveuseddifferent techniquesforreplacingtra- ditionaldiametermeasuringinstruments,amongthemstands outdeviceswithcapability ofgetdepthdatainthefield.Amongthesedevicesarethedepth camerasthatduethe recentdecreaseofpricehavebecomeverypopularincomputer visionapplications.Inor- dertoassistvolumeestimation,thisworksproposesusingdepthcamerastoconductdata acquisitionandanalisysofEucalyptustreediameters.The modeldevelopediscapable toacquirediametersindifferenttreeheights,howeverthe focusismorespecificallyin getdiametersat0.3,0.7and1.3metersfromtheground.Experimentswereconducted inordertocomparetheproposedmodeltotraditionaltechniquesandtheresultsarevery satisfactory. / O inventário florestal é um conjunto de técnicas importantes que fornece informações essenciais para direcionamento racional e sustentável dos recursos disponíveis nas florestas. Por meio dele é possível a caracterização de uma determinada área e do conhecimento quantitativo e qualitativo das espécies que a compõe. Inventários florestais são utilizado sem vários tipos de levantamentos com a finalidade de reconhecimento,diagnóstico e avaliações no campo florestal. A avaliação de estoque de madeira em estudos de viabilidade, planejamento e preparação de talhões de exploração, bem como, diagnóstico pós-exploratório, exigem inventários específicos. Uma das informações essenciais é o diâmetro ao longo do tronco das árvores, que é imprescindível para o cálculo de volume de madeira. Atualmente, para medir esses diâmetros é demandado um período elevado de tempo, sendo passível de erros gerados por defeitos em instrumentos e/ou falhas dos operadores. Alguns estudos têm utilizado técnicas diferentes para substituir o uso de instrumentos tradicionais na tomada das medidas dos diâmetros, entre elas se destaca o uso de dispositivos que podem obter os padrões de profundidade em cenários que contém árvores. Entre os dispositivos capazes de obter profundidade, está as câmeras de profundidade, que vem se popularizando,tornando-se cada vez mais acessíveis,com isso diversas aplicações de visão computacional vêm sendo desenvolvidas, e são capazes de fazer a extração de informações bastante úteis. Este trabalho propõe a utilização de câmeras de profundidade para realizar análise e aquisição de dados que são usados para estimar diâmetros de árvores do gênero Eucalyptus. O modelo desenvolvido para calcular os diâmetros da base das árvores nas alturas de 0,3;0,7 e 1,3 metros em relação ao solo. O modelo proposto, tem por objetivo, o uso dos diâmetros estimados por câmera de profundidade para o cálculo do volume das árvores de eucalipto apartir método apresentado nos trabalhos relacionados. Foram realizados testes a fim de comparar o desempenho do modelo proposto aos métodos tradicionais.Os resultados obtidos foram considerados bastante satisfatórios.

Clones of the Eucalyptus grandis x Eucayptus nitens (GN) hybrids were produced and selected through the CSIR‟s breeding programmes for colder plantation sites in South Africa. Some GN clones consistently exhibit high and superior pulp properties, which makes them valuable for commercial plantations in South Africa. In nurseries, stockplants are usually seven cm in length and maintained at high (100 x1.5 m-2) planting density. However, rooting frequency varies with season and little is known about the impact of position of cuttings on overall rooting frequency of a clone. The aim of this study was to investigate the effect of size and planting density of stockplants in mini-hedges, on the yield and subsequent rooting of cuttings from various positions of GN clones of known rooting potential (i.e. GN 018B: difficult-to-root and PP 2107: easy-to-root clones). Stockplants (10 cm vs. 20 cm) were established at high (100 x 1.5 m-2) and at low (25 x 1.5 m-2) densities for GN 018B and PP 2107 under commercial nursery conditions in a polyethylene tunnel. Cuttings were harvested every two to three weeks in September-October 2010 (spring), December 2010-January 2011 (summer), April-May 2011 (autumn) and June-July 2011 (winter). The harvested material was 5 – 7 cm in length and the light intensity received by individual stockplants at the two planting density levels was recorded. Harvested cuttings from the three positions (apical, middle and basal shoots) were used for: (i) rooting experiments under nursery conditions, (ii) bio-stimulant analysis using the mung bean bioassay, and (iii) analysis of soluble sugars. Between spring and summer 2010, the two GN clones established at low density yielded a similar number of cuttings, but differences in the rooting frequencies were significant in favour of PP 2107 clone. Similar observations were made at high density in terms of production of cuttings, but the significant differences in the rooting observations were reversed between the clones. The GN 018B clone had low rooting rates in summer under nursery conditions but its tissue extracts promoted higher rooting in the bioassay during that time, when compared to spring. Spring and summer had similar effects on rooting responses of PP 2107 cuttings in nursery and bioassay experiments. For both clones, short stockplants produced fewer cuttings but had a higher rooting frequency than cuttings from tall stockplants, with a high rooting frequency recorded from basal cuttings. Similar results were observed in the bioassay experiments which showed high rooting potential of mung bean hypocotyls cuttings using tissue extracts of PP 2107 cuttings maintained at high planting density. Although apical cutting tissues had high concentration of sugars (i.e. sucrose, glucose and fructose), their rooting rates were usually lower at high and low planting density compared to middle and basal cuttings. Sucrose concentration was the highest sugar present in stockplants grown under low planting density. A higher and lower rooting frequency was also observed in autumn although the two clones responded differently to Quambalaria eucalypti (Sporothrix eucalypti) disease infestations. Position, size and genotype had a significant impact on type and concentration of sugar (i.e. sucrose, glucose and fructose), particularly in PP 2107 clone, although rooting rates in the bioassay did not correlate with sugar contents of Eucalyptus cuttings. High carbohydrate (i.e. soluble sugar) content and auxin concentration increased production and subsequent rooting of cuttings across both clones, particularly in spring. Furthermore, rooting was enhanced by relatively higher light intensity intercepted by individual stockplants and in particular the GN 018B clone. Light intensity in the high and low planting densities caused variation in the rooting frequencies thereby increasing or decreasing soluble sugar and auxin concentrations of the two clones. Light intensity and fertiliser concentration received by tall and short stockplants impacted on endogenous hormone levels thereby increasing or decreasing rooting. High sugar concentration levels of PP 2107 clone increased its susceptibility to fungal infection thereby decreasing its rooting frequency in autumn, as its rooting rates increased in winter. Overall results of the investigation revealed that PP 2107 clone has higher rooting potential than GN 018B clone, in particular at high planting density and if stockplants are not infected by fungal diseases. Higher sugar levels were recorded in spring for PP 2107, although rooting rates of mung bean hypocotyl cuttings were higher in summer for GN 018B, suggesting that sugars have nothing to do with rooting of GN cuttings. Season, planting density and size of stockplants affect the rooting frequency of GN clone. Thus, short stockplants maintained at low and high planting densities are recommended for GN 018B and PP 2107 respectively, although the impacts of fertilisers and pathogen resistance on rooting rates still need to be investigated under similar conditions. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Submitted by (ana.araujo@ufrpe.br) on 2016-05-25T15:49:21Z No. of bitstreams: 1 Carlos Sergio Araujo dos Santos.pdf: 1655656 bytes, checksum: 7687ae013a71aadd4e9e9bf4783a172f (MD5) / Made available in DSpace on 2016-05-25T15:49:21Z (GMT). No. of bitstreams: 1 Carlos Sergio Araujo dos Santos.pdf: 1655656 bytes, checksum: 7687ae013a71aadd4e9e9bf4783a172f (MD5) Previous issue date: 2010-01-15 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Box and Cox (1964) developed a numerical procedure to transform the response variable such that the transformed variable should be as closed as possible to the normal distribution. The introduction of a new class of non linear symetric transformed models aims to extended the Box and Cox models to a general class of symetric models. The new class of models inclued all the continuos symmetric distributions with a possible non linear structure to the mean, making possible the use of the new class of regression models. It was applied in the estimate of volumes of the Eucalyptus tereticornis clones, with 7,5 years, planted in the Experimental Station of Araripe of the Agronomic Institute of Pernambuco (IPA), in the municipality of Araripina, in the semiarid of Pernambuco. The non linear model used as pattern was the Schumacher and Hall model. The results indicates that the transformed model with t-Student erros with two degrees of freedon adjusted better to the data set. / Box e Cox (1964) desenvolveram um procedimento numérico para escolher uma transformação da resposta tal que a distribuição da variável transformada esteja o mais próximo possível da distribuição normal. A introdução de uma nova classe de modelos simétricos transformados não lineares visa estender os modelos de Box e Cox para uma classe geral dos modelos simétricos. Esta nova classe de modelos inclui todas as distribuições contínuas simétricas com uma possível estrutura não linear para a média e capacitando o ajustamento de uma larga extensão de modelos para vários tipos de dados. Para ilustrar a utilidade dessa nova classe de modelos de regressão foi realizada uma aplicação na estimativa dos volumes de clones de Eucalyptus tereticornis com 7,5 anos oriundos de um experimento que está sendo realizado no Campo Experimental do Araripe do Instituto Agronômico de Pernambuco (IPA), localizado no Município de Araripina, no semiárido Pernambucano. O modelo não-linear utilizado para explicar os dados foi o modelo Schumacher-Hall. Diante dos resultados obtidos se concluí que o modelo transformado com erros t-Student com dois graus de liberdade foi o que melhor se ajustou os dados.