Submitted by DIEGO GABRIEL TORRES DINI null (diego.torres.dini@gmail.com) on 2017-02-25T21:08:29Z No. of bitstreams: 1 Diego Torres Dini Tese Doutoral.pdf: 1232376 bytes, checksum: dc45dfe7c23a8fd647db24acb963c71c (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-03-07T13:42:52Z (GMT) No. of bitstreams: 1 torresdini_dg_dr_ilha.pdf: 1232376 bytes, checksum: dc45dfe7c23a8fd647db24acb963c71c (MD5) / Made available in DSpace on 2017-03-07T13:42:52Z (GMT). No. of bitstreams: 1 torresdini_dg_dr_ilha.pdf: 1232376 bytes, checksum: dc45dfe7c23a8fd647db24acb963c71c (MD5) Previous issue date: 2017-02-03 / Outra / In Uruguay, reforestation with Eucalyptus sp. is of fundamental importance to produce paper, pulp and wood. The productivity of these continually grows due to application of breeding techniques, such as hybridization. This study aimed to investigate genetic parameters, productivity, stability, adaptability and to identify SNP markers associated with the diameter breast height (DBH) for to select Eucalypts grandis x Eucalyptus globulus full-sibs hybrid clones. The study was conducted in a clonal test, repeated at two different soils, in the state of Rio Negro, Uruguay. The population was phenotypically characterized to the DBH at 48 months of age and cambium tissues of each individual were sampled for genotyping with EuCHIP60K chip. The mean growth in DBH was similar between both places. The genotype-environment interaction was the simple type, with high genotype correlation in clones’ performance between environments (0.708), indicating the possibility of the same clones being selected for both places. Mean heritability between clones (0.724), coefficient of individual genetic variation (10.9%) and relative variation (0.916), showed the possibility of obtaining gains by selecting clones with higher growth, which was estimated in 3.1% for both sites together. A total of 15,196 markers SNPs were used in the genomic selection for the DBH, but after cleaning of SNPs data, the number was reduced for 15,196 (23.5%). The predictive capacity was expected to be low or negative (-0.15) for this population given the population size (78 individuals). We used the model rrBLUP with a validation of Jackknife. The model do not showed precision to predict the DBH. These results were consistent with theoretical expectations, which indicate that it is necessary to have an improvement population of at least 1,000 phenotyped and genotyped individuals. The DBH is the most important trait in the breeding of the genus Eucalyptus. However its quantitative nature added to the time necessary for this phenotype to develop makes the early detection of this trait are difficult. The identification of molecular markers associated with quantitative phenotypes is a good choice for the identification of QTLs that will help the early detection of individuals with high DBH. Significant markers associated to DBH , were indentificated into the chromosome 6, suggesting the presence of a QTL in this chromosome. Since they are clones originated from vegetative propagation and a full-sibs single-progeny, they should preferably be used for reforestation based on their cloning, since mating between clones can generate endogamy by biparental inbreeding. The utilization of SNPs helped to confirm the degree of parentage between the clones as well as clonal identity control.

A large sector of the forestry industry of South Africa comprises Eucalyptus species, covering approximately 49% of the forestry plantation area. Polyploidy induction has become an attractive tool to increase yield and reduce invasiveness in forestry species. Polyploidy induction in Eucalyptus using colchicine treatments on seed and axillary buds was undertaken to produce tetraploids that could be used in breeding programmes; specifically to increase yield and decrease species invasiveness through the production of triploids after crossing with diploid parents. Eight seedlots of E. urophylla and seven of E. grandis were treated with four colchicine concentrations (0.00, 0.01, 0.03, 0.05%) at two exposure times (18 h and 24 h), treating two seeds per treatment, repeated eight times. For axillary bud induction, 20 buds of two E. grandis clones and three E. grandis × E. urophylla hybrids and one E. grandis × E. nitens hybrid were treated with four colchicine concentrations (0.0, 0.5, 1.0, 1.5%) for three consecutive days. A known tetraploid hybrid E. grandis E. camaldulensis and its corresponding diploid were included as reference material. Seedlings and bud sports were pre-screened by determining stomatal guard cell lengths. Seedlings and bud sports displaying cell lengths significantly (p<0.0001) larger than the diploid were selected as putative polyploids. Polyploidy was then confirmed by quantifying the DNA content using flow cytometry. Stomatal frequencies and guard cell chloroplast frequencies were also determined in the induced tetraploid seedlings to evaluate their suitability to discern between ploids. All putative polyploidy seedlings, identified in the pre-screening process, were confirmed, using flow cytometry, as either tetraploids or mixoploids. Of the 17 E. urophylla putative polyploids, from various seedlots, six were tetraploid and 11 mixoploid. In E. grandis one of the five putative polyploids, from various seedlots, was tetraploid and four mixoploid. Pre-screening of bud sports was less accurate; only four of the 12 E. grandis hybrid putative polyploids were mixoploid and only three of the six E. grandis putative polyploids were mixoploid. E. urophylla seedlings were more sensitive to colchicine than E. grandis seedlings displaying a lower survival rate (52%) than E. grandis (63%). Extreme treatments that caused the lowest survival rates were also responsible for most of the polyploidy successful inductions; 0.05%/18 h and 0.05%/24 h for E. urophylla and 0.03%/24 h and 0.05%/24 h for E. grandis. Phenotypic effects of colchicine included shorter, thicker roots and hypocotyls; darker leaves; longer and narrower leaves in some tetraploids; and asymmetrical leaf margins in many mixoploids and tetraploids compared with the controls. In the tetraploids, stomata were significantly larger (p<0.0001) and less frequent (p<0.001). A significant (p<0.001) increase in the number stomatal chloroplasts was also ascertained. Confirmed mixoploid seedlings all displayed tetraploid leaves based on stomatal size and thus classified as periclinal chimeras. In bud sports, only leaves with islands of diploid and tetraploid stomata in the confirmed mixoploids were encountered. Mixoploid bud sports were thus either sectional or mericlinal chimeras. Stomatal size proved to be a suitable pre-screening method, especially in polyploidy induction in seedlings. Additionally confirmed tetraploids exhibited significantly different stomatal frequencies and stomatal chloroplast frequencies compared with the diploids, thus proving to be suitable detection methods for polyploidy screenings. Polyploidy induction in seed was effective, however, less effective in axillary buds which requires further research to refine methods. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

The objective of this study was to develop and implement an advanced generation breeding programme at the Institute for Commercial Forestry Research (ICFR) to manage and integrate the many and disjunct breeding and production populations of Eucalyptus nitens established by various entities over the past 30 years at multiple sites in South Africa. To develop such a breeding strategy, a good understanding of the population genetics, and the underlying assumptions made by tree breeders about the species, was needed. Eucalyptus nitens is an important forestry species grown for pulp and paper production in the temperate, summer rainfall regions of South Africa. A tree improvement programme has been ongoing at the ICFR for three decades. The measurement and statistical analysis of data from eight F1 trials established during the 1980s and 1990s have enabled characterisation of the ICFR’s breeding population. Provenance testing showed that the more northerly New South Wales (Australia) Eucalyptus nitens provenances of Barren Mountain and Barrington Tops are distinctly better suited to growth in South Africa than the southern New South Wales provenances and the Victorian provenances, Penny Saddle and Bendoc. Generally, the species was not badly affected by Coniothyrium canker. High Type B genetic correlations for all sites pairs, except one comparison, ranged from 0.75 to 0.99 for diameter at breast height at 76 to 113 months, indicating very little, or no, genotype by environment interaction for diameter at breast height for the genotypes tested in the F1 generation. Narrow sense heritability estimates ranged from 0.01 to 0.34, indicating that the species provides a breeding opportunity for improvement of diameter growth. High genetic correlations of greater than 0.90 between diameter measurements at 52 to 62 months after establishment and diameter measurements at 94 or 113 months were found, indicating that selections can be made reliably at five or six years. Diameter measurements at both 60 months and full rotation (94 to 113 months) were highly correlated with the final height measurements in these trial series (rg > 0.71 and > 0.83, respectively). Predicted genetic gains for the F2 over the F1 generation were highest in the trials at Goedehoop and Arthur’s Seat, with predicted increases in diameter at breast height of 3.07 cm (17.1%) and 3.17 cm (20.7%), respectively, at full rotation. Genetic improvement in the species has been slower than anticipated due to delayed and infrequent flowering and seed production. Three genetic gain trials were established, firstly, to quantify the gains that have been made in the first generation of improvement in the breeding programme; and secondly, to establish whether a number of seed source and orchard variables influence the performance of the progeny. These variables were: the number of flowering trees in the seed orchard, year of seed collection, seed orchard origin and composition of seed orchard seed bulks. Diameter at breast height and tree height were measured in the trials at between 87 and 97 months after establishment, and timber volumes and survival were calculated. Improved seed orchard bulks performed significantly better (p < 0.01) than unimproved controls in the field trials, and genetic gains ranging from 23.2 to 164.8 m3ha-1 were observed over the unimproved commercial seed. There were significant differences (p < 0.01) in progeny growth between the levels of flowering, with higher levels of flowering (R 40 %) producing substantially greater progeny growth than lower flowering levels (S 20 %). The seed orchard origin had no effect on progeny growth in this trial series. This suggests that seed collected from any of the four seed orchards tested will produce trees with significant improvement in growth. Various scenarios investigating a range of assumptions were developed and used to predict genetic gain in the F2 populations. These were compared with realised gains achieved in the genetic gain trials. The family nested within provenance scenarios proved to be closer to realised gain than the family across provenance predictions. Two scenarios were used for family nested within provenance: Firstly, actual flowering for family nested within provenance; and secondly, estimated flowering after a 30% roguing of poor families. For both scenarios, a coefficient of relationship of 0.33 predicted gains closest to the realised gains. Indications were that the effects were additive, and that very little or no heterosis had occurred. The statistical information suggested that outcrossing in the seed orchards was > 80%. This study provides an objective and quantitative assessment of the underlying assumptions used for estimating genetic parameters, and predicting gain in this population of Eucalyptus nitens. At the same time that genetic gain trials were established, F2 trials were planted, using seedlots collected from F1 seed orchards. Analysis of the two F2 trials showed that realised gains for diameter at breast height at 87 months were close to the predicted values and ranged from 1.02 cm to 1.90 cm. Two exceptions were the sites at Helvetia and Babanango, where gains were under- and over-predicted, respectively. Realised heritability estimates, which are related directly to the realised gain and the actual selection intensities used in the seed orchards, reflected this trend. Estimation of breeding values allowed for selection of elite individuals in top families. Both grand-maternal provenance origin and F1 maternal effects were significant in the F2 trials. A Type B genetic correlation of 0.61 for diameter at 87 months indicated the possible presence of genotype by environment interactions for the two F2 sites. A low narrow sense heritability estimate of 0.06 for diameter at breast height at 87 months at one F2 site indicated that more emphasis should be placed on family information rather than individual information at this site. A heritability estimate of 0.17 for diameter at breast height at 87 months at the second site, however, indicated that further improvement is possible in this population of Eucalyptus nitens. Modelling of predicted genetic gain using various breeding strategy scenarios can be a useful tool in assisting with the decision on which strategy or management plan will deliver the most genetic gains per unit time. Such modelling, using the parameters established in the first part of the study, played an important role in developing the advanced generation breeding strategy for Eucalyptus nitens. In addition, the modelling exercise highlighted various management options which could be used to increase gains in the existing production populations or orchards. Indications are that additional roguing of 1) existing Clonal Seed Orchards based on results of F2 trials (i.e., backward selection); and 2) F1 Breeding Seed Orchards based on stricter provenance selection, will markedly increase the quality of the seed produced from these orchards within one season. This study also highlighted the importance of shortening the breeding cycle in Eucalyptus nitens, particularly in view of the delays caused by reticent flowering and seed production in the species. The information and understanding gathered from this study led to the development of a proposal for an advanced generation breeding strategy in Eucalyptus nitens. This proposal uses parental reconstruction of open-pollinated progeny to secure pedigree information of forward selections, thus combining the benefits of increased genetic gain with a shortened breeding cycle. Recommendations on the management and adaption of current production populations to increase gains have been made, because establishment and management of improved material in seed orchards to ensure a sustainable supply of improved seed to the South African forestry industry, is a key objective of the ICFR Eucalyptus nitens breeding programme. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

Made available in DSpace on 2015-06-17T19:34:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-25. Added 1 bitstream(s) on 2015-06-18T12:49:13Z : No. of bitstreams: 1 000829952.pdf: 2186504 bytes, checksum: 0fe5b3ab3f81a06b3bdec5cf05d69c8a (MD5) / O Eucalyptus é um dos gêneros mais importantes no setor florestal mundial. Por esse motivo, programas de melhoramento genético florestal são desenvolvidos no intuito de aumentar a produtividade, introduzir características desejáveis e reduzir impactos ambientais. No entanto, características deletérias podem ser incorporadas em determinados cruzamentos nos ciclos de melhoramento, seja por endogamia biparental ou segregação de loci heterozigóticos. As anomalias são um exemplo deste efeito e podem acarretar perdas na produção de mudas, na produtividade e atrasos no desenvolvimento de genótipos elite. Portanto, a identificação e caracterização de genes relacionados às anomalias são muito importantes nos programas de melhoramento. Ao realizar um cruzamento controlado entre dois indivíduos de Eucalyptus grandis, a empresa Suzano Papel e Celulose detectou uma anomalia com segregação mendeliana de 3 (normais) :1 (anormais) na progênie. As plântulas anômalas morrem em poucos meses e diferem significativamente em algumas características morfológicas, como altura, diâmetro da base do caule, dimensões e forma do limbo foliar e número de ramificações laterais. Estudos prévios permitiram identificar uma marca molecular ligada à anomalia que apresentou identidade com genes da superfamília Bet v1, família PR10 (pathogenesis-related protein 10). No entanto, não era claro o envolvimento desta família gênica no desenvolvimento da anomalia. Neste cenário, o presente trabalho teve como objetivo a identificação e caracterização dos genes envolvidos na anomalia detectada. Genes e vias metabólicas, diferencialmente expressos entre os fenótipos contrastantes, demonstraram elevada atividade em processos relacionados à resposta de defesa nas plantas anormais. Tais resultados sugerem que a anomalia é causada pela ativação inadequada do sistema imune da planta (resposta autoimune) associado à incompatibilidade ... / Eucalyptus is one of the most important genus in worldwide forestry culture. For this reason forest improvement programs are developed aiming the increase of productivity, the introduction of desirable traits and the reduction of environmental impacts. However deleterious traits can be incorporated in certain crossings through the recurrent improvement cycles either by biparental inbreeding or by segregation of the heterozygous loci. Anomalies are an example of this deleterious effect and they can cause losses in seedling production, productivity and delays in the elite genotypes development. Thus, the identification and characterization of genes related to the anomalies are very important in forest improvement programs. In a controlled cross between two Eucalyptus grandis individuals, the Suzano Papel and Celulose SA company has detected an anomaly with Mendelian segregation ratio of 3 (normal) :1 (abnormal) in the progeny. Abnormal seedlings die in a few months and show significant difference in some morphological characteristics, such as height, stem-base diameter, dimensions and shape of leaf lamina, and number of branches. Previous studies allowed the identification of a molecular marker related to the anomaly that showed identity with Bet v1 superfamily genes, PR10 family (pathogenesis-related protein 10). However, it was not clear the involvement of this gene family in the anomaly. In this scenario, the present study aimed to identify and characterize the genes involved in the detected anomaly. Genes and metabolic pathways, differentially expressed between the contrasting phenotypes, showed high activity of process related to defense response in abnormal plants. These results suggest that the anomaly is caused by the inappropriate activation of the immune system of the plant (autoimmune response) associated with genetic incompatibility. The gene families of thaumatin-like proteins, Bet v1 proteins, and chitinase class I proteins ...

Orientador: Alexandre Magno Sebbenn / Resumo: In Uruguay, reforestation with Eucalyptus sp. is of fundamental importance to produce paper, pulp and wood. The productivity of these continually grows due to application of breeding techniques, such as hybridization. This study aimed to investigate genetic parameters, productivity, stability, adaptability and to identify SNP markers associated with the diameter breast height (DBH) for to select Eucalypts grandis x Eucalyptus globulus full-sibs hybrid clones. The study was conducted in a clonal test, repeated at two different soils, in the state of Rio Negro, Uruguay. The population was phenotypically characterized to the DBH at 48 months of age and cambium tissues of each individual were sampled for genotyping with EuCHIP60K chip. The mean growth in DBH was similar between both places. The genotype-environment interaction was the simple type, with high genotype correlation in clones’ performance between environments (0.708), indicating the possibility of the same clones being selected for both places. Mean heritability between clones (0.724), coefficient of individual genetic variation (10.9%) and relative variation (0.916), showed the possibility of obtaining gains by selecting clones with higher growth, which was estimated in 3.1% for both sites together. A total of 15,196 markers SNPs were used in the genomic selection for the DBH, but after cleaning of SNPs data, the number was reduced for 15,196 (23.5%). The predictive capacity was expected to be low or negative (-0.15)... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

In clonal deployment programmes of plantation species, there is frequently the need to deploy Eucalyptus species and interspecific hybrids as rooted cuttings. However, the rooting ability of a particular species or hybrid is a major, and usually limiting, factor affecting the economics of commercial deployment. There is also significant between-species and between-family variation for this trait. Recently, Eucalyptus longirostrata was crossed with E. grandis in an effort to combine its desirable wood properties, drought tolerance and disease resistance with the latter's vigorous growth. Should progeny with these suitable characteristics be identified, there is the possibility of extending plantations to more marginal areas and increasing the quality and volume from existing plantations. An investigation was undertaken to study the rooting ability of E. grandis x E. longirostrata hybrid cuttings. The plant material was sourced from five families in seedling derived hedges at two nurseries, as well as five families coppiced from an unreplicated progeny trial planted in the midlands of KwaZulu-Natal. Their rooting ability was assessed by determining the percentage of cuttings that developed roots using two different rooting methods. The variation between and within families and clones is presented. The study shows that root strike is under moderate genetic control, with an estimate of broad-sense rooting heritability of 0.197 (S.E. = 0.070). The two nurseries used in this study used different rooting technologies, with cuttings rooted either in media (traditional method) or in air (aeroponically). The aeroponics technology was highly significantly (p<0.0001) superior, in terms of rooting success. Rooting was also highly significantly affected (p<0.0001) by the temperature at the time of cutting. Rooting success of cuttings from seedling-derived parental hedges was similar to cuttings from coppiced stumps. The consequences of the low repeatability of measurements of rooting ability, 0.187 (S.E. 0.067) by clone and 0.340 (S.E. 0.072) by ramet, which was influenced by the response to age of material and nursery conditions, is discussed. This study demonstrated that large improvements in rooting success can be made by the optimization of rooting protocols and selecting for superior genotypes, as long as the performances of genotypes are accurately assessed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

The first objective of this study was to evaluate Eucalyptus urophylla S.T. Blake provenances in terms of their growth, basic wood density and pulp yield properties. The second objective was to determine the genetic and phenotypic associations that may exist between growth, basic wood density and pulp yield. Data of 9022 open-pollinated progenies representing 306 families, collected from 17 provenances, were used to evaluate growth. To evaluate basic wood density and pulp yield, as well as the genetic and phenotypic associations between the three traits, data of 300 open-pollinated progenies representing 30 selected families from 11 provenances were used. Narrow-sense heritabilities for all three traits were estimated from data collected in a single E. urophylla provenance/progeny trial planted in northern KwaZulu-Natal. The results showed that significant provenance effects for growth, basic wood density and pulp yield were observed. Heritability was found to be strong for basic wood density (h2 = 0.51) and moderate to weak for volume growth and pulp yield (h2 = 0.17 and h2 = 0.11, respectively). This suggests that big genetic gains can be achieved for basic wood density. Although the heritability estimates for volume growth and pulp yield were weaker, this still allows for tree breeders to make significant genetic gains through accurate selection from this E. urophylla breeding population. Genetic and phenotypic associations between the three traits were estimated from data collected in the same trial. The genetic correlation between volume growth and pulp yield was positive and moderately strong (rA = 0.66). The genetic correlation estimate between volume growth and basic wood density was found to be negative but weak (rA = -0.08). The genetic association between pulp yield and basic wood density was found to be positive but weak (rA = 0.17). Correlation estimates between volume growth and basic wood density, as well as between pulp yield and basic wood density produced standard errors greater than the correlation itself (s.e. = ± 0.32 and ± 0.22, respectively). These high standard errors, coupled with weak genetic correlations, suggest that these correlation estimates are non-significant, but are probably a result of utilizing a small sample size. However, these correlations have a value in making breeding choices, if treated with caution. Key words: Eucalyptus urophylla, provenance, growth, basic wood density, pulp yield, heritability, genetic correlation / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

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.

Eucalyptus macarthurii is one of the cold tolerant eucalypt species grown in South Africa for pulp and paper. However, little research has been done on this species’ growth performance. A study was therefore initiated to: i) analyse growth characteristics of Eucalyptus macarthurii at two sites and to calculate genetic parameters (genetic and phenotypic correlations, heritabilities and genetic gains), ii) develop a non-destructive near infrared calibration model to predict whole tree pulp yield of Eucalyptus macarthurii, and iii) screen a second generation Eucalyptus macarthurii breeding population, using the developed near infrared calibration model on core samples, to predict screened pulp yield and to rank and identify families with superior pulping properties. Eucalyptus macarthurii population growth data (diameter under bark, diameter over bark, bark thickness, bark stripping, height, basic wood density and stem form) were measured at Pinewoods and Vlakkloof sites and their respective genetic parameters calculated. Genotype by environment interaction was found in this population, indicating that different populations should perhaps be developed independently of each other for the two sites. Genetic and phenotypic correlations between diameter over bark and diameter under bark were, 0.96 and 0.98 for Pinewoods and 0.98 and 0.99 for Vlakkloof, respectively. These correlations indicated that selection of diameter over bark would lead to a positive indirect selection for diameter under bark. The heritability estimates also ranged from 0.03 to 0.23 at both sites, which indicated a reasonable response to selection. The predicted gains for all traits found at Pinewoods were higher than those at Vlakkloof for progeny trials E76/P1, except height for progeny trial E76/P2, which was 2.09m at Pinewoods site and 3.52m at Vlakkloof site which showed that, selection for taller trees will be more effective at Vlakkloof site. A preliminary study was undertaken from eleven second generation trees (2007 tree collection) to investigate if the radial strip core taken at breast height predicts the whole tree wood properties. Correlations found between laboratory Kraft pulping of whole tree wood discs and whole tree NIR spectra with that of the radial strip core NIR spectra were 0.9472 and 0.9506, respectively. These results confirmed that NIR spectra of the radial strip core at breast height predict the whole tree wood properties. A non-destructive near infrared calibration model using wood samples was obtained from Eucalyptus macarthurii felled trees. The wood samples were chipped into wood chips, pulped using Kraft pulping (reference method) and a sub-sample of wood chips of the same trees were ground into sawdust samples and analysed through near infrared spectroscopy for screened pulp yield. The screened pulp yield values obtained from both processes had a narrow screened pulp yield range of 40 to 48%. The Eucalyptus macarthurii screened pulp yield values obtained from both processes, as well as from values obtained from other eucalypt species, were subjected to Vision® Software for calibration and validation of the near infrared calibration model. The results indicated a strong calibration correlation coefficient of 94%, between Kraft pulping and near infrared spectroscopy with a validation coefficient of 89%. The strong correlation and validation coefficient indicated that a reliable non-destructive near infrared model to predict screened pulp yield was successfully developed. The successful development of the valid calibration model required a wider range of other eucalypts species, which improved the development of the model. The developed calibration model was applied to the second generation breeding population planted in KwaZulu-Natal and Mpumalanga provinces, using wood core samples obtained from standing trees for the prediction of screened pulp yield. The highest screened pulp yield achieved was 48%, which compared well to that found for Kraft pulping, which confirmed the success of the development of the calibration model. There was a wide scope of growth variation found amongst traits, which will be useful in selecting superior trees for the next generation. The development of the nondestructive near infrared calibration model was a success due to the strong correlation coefficients found between the screened pulp yields obtained from Kraft pulping and near infrared spectroscopy processes, which was achieved by the inclusion of other eucalypt species in the dataset. The calibration model can be used to select the top performing individual and family trees for the next generation based on screened pulp yield. Tree improvement trials can now be conserved for further breeding, without felling the trees for determination of pulping properties. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Made available in DSpace on 2015-03-26T13:42:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2063853 bytes, checksum: 00be6763da1445cc27e05bdb2481b0ad (MD5) Previous issue date: 2006-02-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Species of Eucalyptus are widely planted in continuous forests stands in our country. To increase the competitiveness of our Eucalyptus based forest industry it is imperative to continuously work toward improving the quality of our plantation forestry. The identification of genes or genomic regions controlling traits of interest has been one of the main molecular breeding approaches to this end. Several groups worldwide have started to identify QTLs for some productivity related traits. Most of these reports, however, have used dominant markers that do not allow data sharing and comparison among the various pedigrees and species. QTL information therefore remains restricted to the particular family used in the detection experiment. The use of codominant, multiallelic, highly polymorphic and transferable microsatellite markers, allows, on the other hand, a comparative mapping investigation across multiple pedigrees and even species of the genus. In this work QTLs were localized based on the genetic mapping of 235 microsatellites in a full-sib family of 188 individuals derived form a Eucalyptus grandis x E. urophylla cross. Microsatellite genotyping was carried out by fluorescence detection on the ABI 3100. Individuals were measured at age of three years for volume growth, wood density by pilodyn penetration as well as eleven other traits related to wood properties assessed by Near Infrared Spectroscopy (NIRS). Single marker analysis was carried out using GQMOL and QTLs were declared at a significance threshold of 1%. Composite interval mapping using QTLCartographer was also used after constructing both parental maps by the pseudo-testcross strategy using MapMaker. QTLs were identified for all 14 traits. Several QTLs for correlated traits mapped to the same genomic intervals. For comparative purposes, sib-pair analysis of Fulker and Cardon was also carried out on the integrated genetic map to detect QTL. A general agreement was seen between the two QTL interval mapping analyses. Finally, to contribute for an ongoing effort to anchor the genetic map to physical equivalents of the Eucalyptus genome, for 38 mapped microsatellites one or more BAC clones were identified by library screening. These BAC clones will be used for the construction of a physical map for future efforts of positional cloning of target genes. The use of BAC clones that belong to specific linkage groups as probes for FISH will also allow establishing the correct numbering of linkage groups based on cytogenetic chromosome numbering, information still lacking for species of Eucalyptus. / Espécies do gênero Eucalyptus são amplamente utilizadas em plantios florestais homogêneos em nosso país. Para aumentar a competitividade da eucaliptocultura nacional são necessárias ações contínuas que visem melhorar as características de nossas florestas. Uma estratégia para buscar regiões genômicas que contenham genes ou seqüências regulatórias envolvidos no controle de caracteres de interesse é o mapeamento genético. Vários grupos de pesquisa identificaram regiões genômicas associadas a caracteres de interesse em Eucalyptus via mapeamento genético. Esses trabalhos, em sua maioria, utilizaram marcadores dominantes, que dificultam o compartilhamento interexperimental dos dados fazendo com que o uso das informações de ligação marcador/característica fique restrito ao pedigree utilizado. A utilização de microssatélites, marcadores codominantes, multialélicos, altamente polimórficos, e transferíveis, permite, por outro lado, a análise comparativa de QTLs entre pedigrees e espécies do gênero. No presente trabalho foram localizados QTLs com base no mapeamento de 235 microssatélites em uma família de 188 irmãos- completos, proveniente de um cruzamento entre Eucalyptus grandis x E. urophylla. A detecção do polimorfismo dos microssatélites foi realizada via fluorescência na plataforma ABI 3100. Os indivíduos desta família foram avaliados aos três anos para altura e diâmetro das árvores, densidade da madeira via penetração do Pilodyn e mais onze caracteres relacionados à qualidade da madeira, os quais foram avaliados indiretamente por Espectrofotometria de Infravermelho Próximo (NIRS). Os marcadores foram testados individualmente quanto à ligação a QTLs através de uma análise de variância no programa GQMOL. Marcadores significativamente ligados a QTLs foram identificados para todas as características com um nível de significância de 1% para cada marca individual. Também foi realizado mapeamento de QTLs através da metodologia de intervalo composto no programa QTLCartographer. Para isso, foram construídos mapas de ligação para cada parental utilizando a estratégia de pseudo-cruzamento teste no programa MapMaker. Através dessa estratégia, foram identificados QTLs para todas as quatorze características. Muitos dos QTLs, principalmente para caracteres correlacionados, foram identificados de forma co-localizada. Para fins comparativos, também foram realizadas análises de QTLs por intervalo em mapa integrado através do método de Fulker e Cardon, que utiliza uma regressão linear onde a variável dependente é o quadrado da diferença fenotípica entre pares de irmãos e a variável independente é a proporção de alelos idênticos por descendência (IBD) nos diferentes intervalos do mapa genético. Em geral, houve concordância entre os QTLs identificados por ambas metodologias de mapeamento por intervalo. Por fim, visando contribuir para a ancoragem do mapa genético com correspondentes físicos do genoma, para 38 microssatélites mapeados foram identificados um ou mais clones de cromossomos artificiais de bactérias (BAC). Esses clones serão utilizados para a construção de um mapa físico no âmbito do Projeto Genolyptus, etapa fundamental para um possível esforço de clonagem posicional de genes que controlam características quantitativas. A utilização de clones BAC pertencentes a grupos de ligação específicos, como sondas de FISH, permitirá ainda o estabelecimento da correta numeração de grupos de ligação com base na numeração citogenética de cromossomos, informação indisponível até o momento para o gênero Eucalyptus.