Jose Rodrigues | Universidade de Lisboa (original) (raw)
Papers by Jose Rodrigues
Journal of Economic Entomology, 2015
Four common Portuguese rice varieties-Thaibonnet, Gladio, Albatros, and Eurosis-were tested for t... more Four common Portuguese rice varieties-Thaibonnet, Gladio, Albatros, and Eurosis-were tested for their relative susceptibility to Sitophilus zeamais Motschulsky, a common pest of stored rice in Portugal and in tropical countries. Physical (moisture content, hardness, length, and width) and chemical (by attenuated total reflection-Fourier transform infrared spectroscopy) properties of rice kernels were measured. Insect bioassays measured median developmental time, Dobie's index of susceptibility, percentage of damaged grains and weight loss, and progeny developed. This was done for paddy, brown rice, and polished rice for each variety. There were small, but significant, differences in insect resistance among the varieties. However, it was different for paddy and polished rice. In paddy, these differences were correlated with hull damage, and Eurosis was the most susceptible variety. In polished rice, resistance was correlated with hardness, and Thaibonnet was the most susceptible variety. In general, paddy rice was more resistant to insect attack, followed by polished rice and then brown rice. Paddy kernels selected with undamaged hull were completely resistant to attack. Implications for IPM and breeding for resistant varieties are discussed.
Cerne
RESUMO: O crescente aumento do consumo de madeira de rápido crescimento, o expressivo crescimento... more RESUMO: O crescente aumento do consumo de madeira de rápido crescimento, o expressivo crescimento na demanda de painéis de madeira e a necessidade de tecnologias para a utilização de insumos considerados como resíduos constituem desafios no desenvolvimento de novos produtos. Neste estudo, partículas de bagacilho de cana-de-açúcar (Saccharum spp) foram misturadas, em percentual até 100%, com fibra de Eucalyptus grandis para a produção de painéis, tendo como agente aglutinante resina ureia formaldeído. Os módulos de elasticidade (MOE) e de ruptura (MOR) dos painéis confeccionados com 75% de bagacilho de cana-de-açúcar não foram afetados significativamente, porém, com 100% dessa matéria-prima, não se enquadraram na NBR 15316 (2006). O estudo indica a viabilidade de utilização de partículas de bagacilho de cana-de-açúcar com fibras de Eucalyptus grandis na manufatura de painéis. Palavras-chave: Bagacilho de cana-de-açúcar, eucalipto, painéis de madeira, anatomia, propriedades tecnológic...
É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um vasto con... more É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um vasto conjunto de factores, como sejam a localização geográfica, condições do solo, do clima, genéticos, etc. Perante o crescente interesse da influência dos factores ambientais sobre o crescimento das árvores, particularmente sob a actual ameaça de ocorrência de alterações climáticas, no presente trabalho e recorrendo à microdensitometria da madeira por raios-x, foi analisado o efeito da actividade solar nas características dos anéis de crescimento de uma árvore de Pinus Sylvestris L. com 180 anos, localizada no Observatório Central de Hurbanovo (Eslováquia). Os resultados obtidos revelaram que a actividade solar poderá afectar o crescimento e a densidade da madeira sendo, responsável por cerca de 20% da variação total de algumas características da madeira. Verificou-se que o efeito da actividade solar é mais acentuado nas características da densidade e do crescimento da madeira formada durante ...
Estacas em enraizamento, retiradas de jovens plantas de sobreiro com 7 meses, foram utilizadas na... more Estacas em enraizamento, retiradas de jovens plantas de sobreiro com 7 meses, foram utilizadas na recolha de amostras para acompanhamento anatomo-histológico das modificações estruturais da sua base. As plantas-mãe foram submetidas durante um mês a um pré-tratamento de escurecimento, que consistiu no envolvimento da parte do caule correspondente à futura base da estaca por uma banda preta. Em metade das plantas sujeitas ao escurecimento aplicou-se auxina (AIB em pó, na concentração de 0,5%) antes da colocação da banda preta. Para a montagem do ensaio de enraizamento, as estacas foram preparadas com cerca de 7 cm e, em cada grupo dos pré-tratamentos prévios das plantas mãe (só escurecimento ou escurecimento e AIB), metade foram tratadas com AIB na mesma formulação e dosagem. Realizaram-se seis colheitas de material (base das estacas em enraizamento), ao longo do mês que se seguiu ao início do ensaio, para posterior observação de cortes histológicos. No dia 0 observaram-se diferenças ...
En este trabajo se presentan los resultados alcanzados en la determinación del contenido de ligni... more En este trabajo se presentan los resultados alcanzados en la determinación del contenido de lignina así como de su calidad (relación H/G) en muestras de madera de Pinus caribaea var caribaea de tres localidades en la provincia de Pinar del Río, Cuba. El estudio se realizó en el Instituto de Investigación Científica Tropical de Lisboa, Portugal, en el marco del Proyecto GEMA. La técnica utilizada fue la Pirólisis analítica. Los resultados que se muestran representan el promedio de tres corridas experimentales y se obtuvieron valores cercanos al método Klason utilizado como referencia. Se encontró una correlación aceptable entre los contenidos del lignina-pirólisis y lignina Klason para esta especie, lo cual permite calcular el contenido de lignina Klason a través del contenido de ligninapirólisis. La pirólisis analítica es de gran utilidad en los programas de mejoramiento genético, en que es necesario el análisis de muchas muestras, ya que la introducción de parámetros como la composición química de la madera, induce al desarrollo de métodos expeditos de caracterización, reproducibles y de bajo costo, una vez que los métodos tradicionales son lentos, requieren mucha mano de obra y son de elevado costo.
Microchemical Journal, 2015
Assessment of lignin and holocellulose in decayed wood by NIR-FTIR and PLS regression.Several sam... more Assessment of lignin and holocellulose in decayed wood by NIR-FTIR and PLS regression.Several samples analysed of various species and of different state of preservation.Different models for lignin/holocellulose and for each data set (softwoods/hardwoods).Stability of best models established by the leave-more-out (LMO) method.Model predictive ability affected by high ash content.Present work describes the application of NIR spectroscopy coupled with Partial least square (PLS) regression to estimate the residual chemical composition (in terms of holocellulose and lignin) of wood decayed by attack of biotic agents (such as bacteria) when preserved for a long-time in waterlogged conditions. The evaluations allowed assessing how various parameters may influence the predictive ability of calibration models. These parameters include: pre-processing manipulations (first and second derivatives curves, both normalized and not, were compared with baseline corrected spectra), the ranges used for model calibration, the preliminary conditioning of the samples (meals conditioned at both 22 °C/50% r.h. and 60 °C), and the way to take account of the presence of inorganic fillers permeating wood. To such aim, 59 samples from different excavations were considered, with samples belonging to several hardwoods and softwoods (Alnus sp.p., Cupressus sempervirens, Larix decidua, Picea abies, Pinus sp.p., Quercus sp.p., Ulmus sp.p.), and to different states of preservation and burial environments. Values used for calibration were obtained by conventional wet analyses. Results showed that NIR spectroscopy coupled with PLS multivariate analysis could be used to reliably assess the residual chemical composition of waterlogged decayed wood provided that the calibration range is carefully selected and that original data are suitably pre-processed. However, the best models were different for the two considered components (lignin and holocellulose) and depending on which data set (softwoods or hardwoods) the samples belonged. Finally, it was also shown that the models predictive ability is affected by high ash content (too contaminated samples had to be excluded in order to attain good results).
Resumo:É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um va... more Resumo:É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um vasto conjunto de factores, como sejam a localização geográfica, condições do solo, do clima, genéticos, etc. Perante o crescente interesse da influência dos factores ambientais sobre o crescimento das árvores, particularmente sob a actual ameaça de ocorrência de alterações climáticas, no presente trabalho e recorrendo à microdensitometria da madeira por raios-x, foi analisado o efeito da actividade solar nas características dos anéis de crescimento de uma árvore de Pinus Sylvestris L. com 180 anos, localizada no Observatório Central de Hurbanovo (Eslováquia). Os resultados obtidos revelaram que a actividade solar poderá afectar o crescimento e a densidade da madeira sendo, responsável por cerca de 20% da variação total de algumas características da madeira. Verificou-se que o efeito da actividade solar é mais acentuado nas características da densidade e do crescimento da madeira formada durante o Verão/Outono (Lenho Final), do que na madeira formada durante a Primavera (Lenho Inicial). Verificou-se que nos anos de maior actividade solar as árvores formaram anéis com menor Densidade Máxima e Densidade do Lenho Final e, por isso, também menor Densidade Média e Índice de Heterogeneidade. Relativamente às características de crescimento, estes anéis apresentaram também uma redução da Largura do Lenho Final, Percentagem de Lenho Final e Largura do Anel.
BioResources, 2014
A total of 120 Acacia melanoxylon R. Br. (Australian blackwood) stem discs, belonging to 20 trees... more A total of 120 Acacia melanoxylon R. Br. (Australian blackwood) stem discs, belonging to 20 trees from four sites in Portugal, were used in this study. The samples were kraft pulped under standard identical conditions targeted to a Kappa number of 15. A Near Infrared (NIR) partial least squares regression (PLSR) model was developed for the Kappa number prediction using 75 pulp samples with a narrow Kappa number variation range of 10 to 17. Very good correlations between NIR spectra of A. melanoxylon pulps and Kappa numbers were obtained. Besides the raw spectra, also pre-processed spectra with ten methods were used for PLS analysis (cross validation with 48 samples), and a test set validation was made with 27 samples. The first derivative spectra in the wavenumber range from 6110 to 5440 cm -1 yielded the best model with a root mean square error of prediction of 0.4 units of Kappa number, a coefficient of determination of 92.1%, and two PLS components, with the ratios of performance to deviation (RPD) of 3.6 and zero outliers. The obtained NIR-PLSR model for Kappa number determination is sufficiently accurate to be used in screening programs and in quality control.
BMC Proceedings, 2011
The economic importance of some Eucalyptus species, including interspecific hybrids, has been ext... more The economic importance of some Eucalyptus species, including interspecific hybrids, has been extended from the traditional interest of pulp and paper production to the emergent areas of bio-fuels and bio-materials. New genomic resources and high throughput technologies have provided the Eucalyptus research international community with the opportunities to identify genomic regions of interest in order to comprehensively dissect, catalogue and characterize genes involved in the determination of wood formation and quality. Similar strategies can be now applied to identify key regulator genes and better understand the cellular mechanisms by which they modulate the complex molecular events occurring in xylogenesis.
G3: Genes, Genomes, Genetics, 2011
Despite the ecological and economic importance of lignin and other wood chemical components, ther... more Despite the ecological and economic importance of lignin and other wood chemical components, there are few studies of the natural genetic variation that exists within plant species and its adaptive significance. We used models developed from near infra-red spectroscopy to study natural genetic variation in lignin content and monomer composition (syringyl-to-guaiacyl ratio [S/G]) as well as cellulose and extractives content, using a 16-year-old field trial of an Australian tree species, Eucalyptus globulus. We sampled 2163 progenies of 467 native trees from throughout the native geographic range of the species. The narrow-sense heritability of wood chemical traits (0.25-0.44) was higher than that of growth (0.15), but less than wood density (0.51). All wood chemical traits exhibited significant broad-scale genetic differentiation (Q ST = 0.34-0.43) across the species range. This differentiation exceeded that detected with putatively neutral microsatellite markers (F ST = 0.09), arguing that diversifying selection has shaped population differentiation in wood chemistry. There were significant genetic correlations among these wood chemical traits at the population and additive genetic levels. However, population differentiation in the S/G ratio of lignin in particular was positively correlated with latitude (R 2 = 76%), which may be driven by either adaptation to climate or associated biotic factors.
Crop wild relative conservation and use, 2007
Abstract The aim of this work was to establish:(i) conservation strategies (ex situ and in situ) ... more Abstract The aim of this work was to establish:(i) conservation strategies (ex situ and in situ) for Quercus ilex subsp. rotundifolia in Portugal; and (ii) the application of a selection programme towards the genetic improvement of important agricultural quantitative traits, in this case the'oil content'of the acorn. Results showed clearly that both montados, as an agro-silvicultural ecosystem, and Q. ilex subsp. rotundifolia are declining in distributional range in southern Portugal and there is an urgent need for a coherent conservation strategy. One ...
Molecular Breeding, 2003
A procedure for A. tumefaciens-mediated genetic transformation of a juvenile E. camaldulensis clo... more A procedure for A. tumefaciens-mediated genetic transformation of a juvenile E. camaldulensis clone is presented. CAD antisense full-length cDNAs from Eucalyptus gunnii or Nicotiana tabacum was introduced under the control of the CaMV 35S DE promoter. From 44 individual transgenic shoots selected by PCR analysis, 32% exhibited a significant reduction of CAD activity, up to 83%. The use of the heterologous tobacco CAD cDNA construct was less efficient (up to 65% reduction). Transcript levels in 3 lines obtained using the homologous eucalyptus cDNA confirmed the under-expression of the CAD gene, and Southern blot data indicated a low transgene copy number ranging between 1 and 3. The most down-regulated plant contained a single transgene copy. Therefore, for the first time in eucalyptus, genetically modified plantlets exhibiting a strong inhibition of CAD activity associated with decreased transcription were recovered. Five transgenic lines, transferred to the greenhouse for 10 months, went through a wood chemical analysis that showed no differences in lignin quantity (through Fourier transform infrared spectroscopy), composition (through analytical pyrolysis) or pulp yield (through Kraft pulping) compared to control trees. Despite the down-regulation of the CAD gene in this Eucalyptus species of economic interest, the lack of significant changes in lignin profiles indicates that probably the trees were not sufficiently suppressed in CAD throughout development to exhibit obvious modifications in lignin and pulping. This raises the problem of the requirements for an efficient modulation of lignification in trees such as eucalyptus.
Journal of Economic Entomology, 2015
Four common Portuguese rice varieties-Thaibonnet, Gladio, Albatros, and Eurosis-were tested for t... more Four common Portuguese rice varieties-Thaibonnet, Gladio, Albatros, and Eurosis-were tested for their relative susceptibility to Sitophilus zeamais Motschulsky, a common pest of stored rice in Portugal and in tropical countries. Physical (moisture content, hardness, length, and width) and chemical (by attenuated total reflection-Fourier transform infrared spectroscopy) properties of rice kernels were measured. Insect bioassays measured median developmental time, Dobie's index of susceptibility, percentage of damaged grains and weight loss, and progeny developed. This was done for paddy, brown rice, and polished rice for each variety. There were small, but significant, differences in insect resistance among the varieties. However, it was different for paddy and polished rice. In paddy, these differences were correlated with hull damage, and Eurosis was the most susceptible variety. In polished rice, resistance was correlated with hardness, and Thaibonnet was the most susceptible variety. In general, paddy rice was more resistant to insect attack, followed by polished rice and then brown rice. Paddy kernels selected with undamaged hull were completely resistant to attack. Implications for IPM and breeding for resistant varieties are discussed.
Cerne
RESUMO: O crescente aumento do consumo de madeira de rápido crescimento, o expressivo crescimento... more RESUMO: O crescente aumento do consumo de madeira de rápido crescimento, o expressivo crescimento na demanda de painéis de madeira e a necessidade de tecnologias para a utilização de insumos considerados como resíduos constituem desafios no desenvolvimento de novos produtos. Neste estudo, partículas de bagacilho de cana-de-açúcar (Saccharum spp) foram misturadas, em percentual até 100%, com fibra de Eucalyptus grandis para a produção de painéis, tendo como agente aglutinante resina ureia formaldeído. Os módulos de elasticidade (MOE) e de ruptura (MOR) dos painéis confeccionados com 75% de bagacilho de cana-de-açúcar não foram afetados significativamente, porém, com 100% dessa matéria-prima, não se enquadraram na NBR 15316 (2006). O estudo indica a viabilidade de utilização de partículas de bagacilho de cana-de-açúcar com fibras de Eucalyptus grandis na manufatura de painéis. Palavras-chave: Bagacilho de cana-de-açúcar, eucalipto, painéis de madeira, anatomia, propriedades tecnológic...
É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um vasto con... more É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um vasto conjunto de factores, como sejam a localização geográfica, condições do solo, do clima, genéticos, etc. Perante o crescente interesse da influência dos factores ambientais sobre o crescimento das árvores, particularmente sob a actual ameaça de ocorrência de alterações climáticas, no presente trabalho e recorrendo à microdensitometria da madeira por raios-x, foi analisado o efeito da actividade solar nas características dos anéis de crescimento de uma árvore de Pinus Sylvestris L. com 180 anos, localizada no Observatório Central de Hurbanovo (Eslováquia). Os resultados obtidos revelaram que a actividade solar poderá afectar o crescimento e a densidade da madeira sendo, responsável por cerca de 20% da variação total de algumas características da madeira. Verificou-se que o efeito da actividade solar é mais acentuado nas características da densidade e do crescimento da madeira formada durante ...
Estacas em enraizamento, retiradas de jovens plantas de sobreiro com 7 meses, foram utilizadas na... more Estacas em enraizamento, retiradas de jovens plantas de sobreiro com 7 meses, foram utilizadas na recolha de amostras para acompanhamento anatomo-histológico das modificações estruturais da sua base. As plantas-mãe foram submetidas durante um mês a um pré-tratamento de escurecimento, que consistiu no envolvimento da parte do caule correspondente à futura base da estaca por uma banda preta. Em metade das plantas sujeitas ao escurecimento aplicou-se auxina (AIB em pó, na concentração de 0,5%) antes da colocação da banda preta. Para a montagem do ensaio de enraizamento, as estacas foram preparadas com cerca de 7 cm e, em cada grupo dos pré-tratamentos prévios das plantas mãe (só escurecimento ou escurecimento e AIB), metade foram tratadas com AIB na mesma formulação e dosagem. Realizaram-se seis colheitas de material (base das estacas em enraizamento), ao longo do mês que se seguiu ao início do ensaio, para posterior observação de cortes histológicos. No dia 0 observaram-se diferenças ...
En este trabajo se presentan los resultados alcanzados en la determinación del contenido de ligni... more En este trabajo se presentan los resultados alcanzados en la determinación del contenido de lignina así como de su calidad (relación H/G) en muestras de madera de Pinus caribaea var caribaea de tres localidades en la provincia de Pinar del Río, Cuba. El estudio se realizó en el Instituto de Investigación Científica Tropical de Lisboa, Portugal, en el marco del Proyecto GEMA. La técnica utilizada fue la Pirólisis analítica. Los resultados que se muestran representan el promedio de tres corridas experimentales y se obtuvieron valores cercanos al método Klason utilizado como referencia. Se encontró una correlación aceptable entre los contenidos del lignina-pirólisis y lignina Klason para esta especie, lo cual permite calcular el contenido de lignina Klason a través del contenido de ligninapirólisis. La pirólisis analítica es de gran utilidad en los programas de mejoramiento genético, en que es necesario el análisis de muchas muestras, ya que la introducción de parámetros como la composición química de la madera, induce al desarrollo de métodos expeditos de caracterización, reproducibles y de bajo costo, una vez que los métodos tradicionales son lentos, requieren mucha mano de obra y son de elevado costo.
Microchemical Journal, 2015
Assessment of lignin and holocellulose in decayed wood by NIR-FTIR and PLS regression.Several sam... more Assessment of lignin and holocellulose in decayed wood by NIR-FTIR and PLS regression.Several samples analysed of various species and of different state of preservation.Different models for lignin/holocellulose and for each data set (softwoods/hardwoods).Stability of best models established by the leave-more-out (LMO) method.Model predictive ability affected by high ash content.Present work describes the application of NIR spectroscopy coupled with Partial least square (PLS) regression to estimate the residual chemical composition (in terms of holocellulose and lignin) of wood decayed by attack of biotic agents (such as bacteria) when preserved for a long-time in waterlogged conditions. The evaluations allowed assessing how various parameters may influence the predictive ability of calibration models. These parameters include: pre-processing manipulations (first and second derivatives curves, both normalized and not, were compared with baseline corrected spectra), the ranges used for model calibration, the preliminary conditioning of the samples (meals conditioned at both 22 °C/50% r.h. and 60 °C), and the way to take account of the presence of inorganic fillers permeating wood. To such aim, 59 samples from different excavations were considered, with samples belonging to several hardwoods and softwoods (Alnus sp.p., Cupressus sempervirens, Larix decidua, Picea abies, Pinus sp.p., Quercus sp.p., Ulmus sp.p.), and to different states of preservation and burial environments. Values used for calibration were obtained by conventional wet analyses. Results showed that NIR spectroscopy coupled with PLS multivariate analysis could be used to reliably assess the residual chemical composition of waterlogged decayed wood provided that the calibration range is carefully selected and that original data are suitably pre-processed. However, the best models were different for the two considered components (lignin and holocellulose) and depending on which data set (softwoods or hardwoods) the samples belonged. Finally, it was also shown that the models predictive ability is affected by high ash content (too contaminated samples had to be excluded in order to attain good results).
Resumo:É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um va... more Resumo:É sabido que as características da madeira produzidas pelas árvores estão sujeitas a um vasto conjunto de factores, como sejam a localização geográfica, condições do solo, do clima, genéticos, etc. Perante o crescente interesse da influência dos factores ambientais sobre o crescimento das árvores, particularmente sob a actual ameaça de ocorrência de alterações climáticas, no presente trabalho e recorrendo à microdensitometria da madeira por raios-x, foi analisado o efeito da actividade solar nas características dos anéis de crescimento de uma árvore de Pinus Sylvestris L. com 180 anos, localizada no Observatório Central de Hurbanovo (Eslováquia). Os resultados obtidos revelaram que a actividade solar poderá afectar o crescimento e a densidade da madeira sendo, responsável por cerca de 20% da variação total de algumas características da madeira. Verificou-se que o efeito da actividade solar é mais acentuado nas características da densidade e do crescimento da madeira formada durante o Verão/Outono (Lenho Final), do que na madeira formada durante a Primavera (Lenho Inicial). Verificou-se que nos anos de maior actividade solar as árvores formaram anéis com menor Densidade Máxima e Densidade do Lenho Final e, por isso, também menor Densidade Média e Índice de Heterogeneidade. Relativamente às características de crescimento, estes anéis apresentaram também uma redução da Largura do Lenho Final, Percentagem de Lenho Final e Largura do Anel.
BioResources, 2014
A total of 120 Acacia melanoxylon R. Br. (Australian blackwood) stem discs, belonging to 20 trees... more A total of 120 Acacia melanoxylon R. Br. (Australian blackwood) stem discs, belonging to 20 trees from four sites in Portugal, were used in this study. The samples were kraft pulped under standard identical conditions targeted to a Kappa number of 15. A Near Infrared (NIR) partial least squares regression (PLSR) model was developed for the Kappa number prediction using 75 pulp samples with a narrow Kappa number variation range of 10 to 17. Very good correlations between NIR spectra of A. melanoxylon pulps and Kappa numbers were obtained. Besides the raw spectra, also pre-processed spectra with ten methods were used for PLS analysis (cross validation with 48 samples), and a test set validation was made with 27 samples. The first derivative spectra in the wavenumber range from 6110 to 5440 cm -1 yielded the best model with a root mean square error of prediction of 0.4 units of Kappa number, a coefficient of determination of 92.1%, and two PLS components, with the ratios of performance to deviation (RPD) of 3.6 and zero outliers. The obtained NIR-PLSR model for Kappa number determination is sufficiently accurate to be used in screening programs and in quality control.
BMC Proceedings, 2011
The economic importance of some Eucalyptus species, including interspecific hybrids, has been ext... more The economic importance of some Eucalyptus species, including interspecific hybrids, has been extended from the traditional interest of pulp and paper production to the emergent areas of bio-fuels and bio-materials. New genomic resources and high throughput technologies have provided the Eucalyptus research international community with the opportunities to identify genomic regions of interest in order to comprehensively dissect, catalogue and characterize genes involved in the determination of wood formation and quality. Similar strategies can be now applied to identify key regulator genes and better understand the cellular mechanisms by which they modulate the complex molecular events occurring in xylogenesis.
G3: Genes, Genomes, Genetics, 2011
Despite the ecological and economic importance of lignin and other wood chemical components, ther... more Despite the ecological and economic importance of lignin and other wood chemical components, there are few studies of the natural genetic variation that exists within plant species and its adaptive significance. We used models developed from near infra-red spectroscopy to study natural genetic variation in lignin content and monomer composition (syringyl-to-guaiacyl ratio [S/G]) as well as cellulose and extractives content, using a 16-year-old field trial of an Australian tree species, Eucalyptus globulus. We sampled 2163 progenies of 467 native trees from throughout the native geographic range of the species. The narrow-sense heritability of wood chemical traits (0.25-0.44) was higher than that of growth (0.15), but less than wood density (0.51). All wood chemical traits exhibited significant broad-scale genetic differentiation (Q ST = 0.34-0.43) across the species range. This differentiation exceeded that detected with putatively neutral microsatellite markers (F ST = 0.09), arguing that diversifying selection has shaped population differentiation in wood chemistry. There were significant genetic correlations among these wood chemical traits at the population and additive genetic levels. However, population differentiation in the S/G ratio of lignin in particular was positively correlated with latitude (R 2 = 76%), which may be driven by either adaptation to climate or associated biotic factors.
Crop wild relative conservation and use, 2007
Abstract The aim of this work was to establish:(i) conservation strategies (ex situ and in situ) ... more Abstract The aim of this work was to establish:(i) conservation strategies (ex situ and in situ) for Quercus ilex subsp. rotundifolia in Portugal; and (ii) the application of a selection programme towards the genetic improvement of important agricultural quantitative traits, in this case the'oil content'of the acorn. Results showed clearly that both montados, as an agro-silvicultural ecosystem, and Q. ilex subsp. rotundifolia are declining in distributional range in southern Portugal and there is an urgent need for a coherent conservation strategy. One ...
Molecular Breeding, 2003
A procedure for A. tumefaciens-mediated genetic transformation of a juvenile E. camaldulensis clo... more A procedure for A. tumefaciens-mediated genetic transformation of a juvenile E. camaldulensis clone is presented. CAD antisense full-length cDNAs from Eucalyptus gunnii or Nicotiana tabacum was introduced under the control of the CaMV 35S DE promoter. From 44 individual transgenic shoots selected by PCR analysis, 32% exhibited a significant reduction of CAD activity, up to 83%. The use of the heterologous tobacco CAD cDNA construct was less efficient (up to 65% reduction). Transcript levels in 3 lines obtained using the homologous eucalyptus cDNA confirmed the under-expression of the CAD gene, and Southern blot data indicated a low transgene copy number ranging between 1 and 3. The most down-regulated plant contained a single transgene copy. Therefore, for the first time in eucalyptus, genetically modified plantlets exhibiting a strong inhibition of CAD activity associated with decreased transcription were recovered. Five transgenic lines, transferred to the greenhouse for 10 months, went through a wood chemical analysis that showed no differences in lignin quantity (through Fourier transform infrared spectroscopy), composition (through analytical pyrolysis) or pulp yield (through Kraft pulping) compared to control trees. Despite the down-regulation of the CAD gene in this Eucalyptus species of economic interest, the lack of significant changes in lignin profiles indicates that probably the trees were not sufficiently suppressed in CAD throughout development to exhibit obvious modifications in lignin and pulping. This raises the problem of the requirements for an efficient modulation of lignification in trees such as eucalyptus.