Cholesterol oxides inhibit cholesterol esterification by lecithin: cholesterol acyl transferase

Cholesterol oxides are atherogenic and can affect the activity of diverse important enzymes for the lipidic metabolism. The effect of 7β-hydroxycholesterol, 7-ketocholesterol, 25-hydroxycholesterol, cholestan-3β,5α,6β-triol,5,6β-epoxycholesterol, 5,6α-epoxycholesterol and 7α-hydroxycholesterol on esterification of cholesterol by lecithin:cholesterol acyl transferase (LCAT, EC 2.3.1.43) and the transfer of esters of cholesterol oxides from high density lipoprotein (HDL) to low density lipoproteins (LDL) and very low density lipoproteins (VLDL) by cholesteryl ester transfer protein (CETP) was investigated. HDL enriched with increasing concentrations of cholesterol oxides was incubated with fresh plasma as source of LCAT. Cholesterol and cholesterol oxides esterification was followed by measuring the consumption of respective free sterol and oxysterols. Measurements of cholesterol and cholesterol oxides were done by gas-chromatography. 14C-cholesterol oxides were incorporated into HDL2 and HDL3 subfractions and then incubated with fresh plasma containing LCAT and CETP. The transfer of cholesterol oxide esters was followed by measuring the 14C-cholesterol oxide-derived esters transferred to LDL and VLDL. All the cholesterol oxides studied were esterified by LCAT after incorporation into HDL particles, competing with cholesterol by LCAT. Cholesterol esterification by LCAT was inversely related to the cholesterol oxide concentration. The esterification of 14C-cholesterol oxides was higher in HDL3 and the transfer of the derived esters was greater from HDL2 to LDL and VLDL. The results suggest that cholesterol esterification by LCAT is inhibited in cholesterol oxide-enriched HDL particles. Moreover, the cholesterol oxides-derived esters are efficiently transferred to LDL and VLDL. Therefore, we suggest that cholesterol oxides may exert part of their atherogenic effect by inhibiting cholesterol esterification on the HDL surface and thereby disturbing reverse cholesterol transport.Os óxidos de colesterol são aterogênicos e podem afetar a atividade de diversas enzimas importantes para o metabolismo lipídico. Este estudo investigou o efeito dos óxidos 7β-hidroxicolesterol, 7-cetocolesterol, 25-hidroxicolesterol, colestan-3β,5α,6β-triol, 5,6β-epoxicolesterol, 5,6α-epoxicolesterol e 7α-hidroxicolesterol na esterificação do colesterol por ação da lecitina colesterol aciltransferase (LCAT, EC 2.3.1.43) e a posterior transferência dos óxidos esterificados da lipoproteína de alta densidade (HDL) para as lipoproteínas de baixa densidade (LDL) e muito baixa densidade (VLDL) mediada pela proteína de transporte de éster de colesterol (CETP). Para atingir os objetivos, HDL enriquecida com concentrações crescentes de óxidos de colesterol foi incubada com plasma fresco pobre em lipoproteínas, como fonte de LCAT; posteriormente a esterificação do colesterol e dos óxidos de colesterol foi medida pelo consumo do colesterol livre e dos óxidos livres presentes na HDL. As determinações de colesterol e dos óxidos de colesterol foram realizadas por cromatografia gasosa. 14C-óxidos de colesterol foram incorporados nas subfrações HDL2 e HDL3 e posteriormente incubados com plasma fresco, contendo LCAT e CETP. A transferência dos ésteres de óxidos de colesterol foi medida e quantificada pela presença desses ésteres na LDL e VLDL. Todos os óxidos de colesterol estudados foram esterificados pela LCAT após incorporação nas partículas de HDL e competiram com a esterificação do colesterol nativo. A esterificação do colesterol pela LCAT foi inversamente relacionada à concentração de óxidos de colesterol. A esterificação dos óxidos de colesterol foi maior na HDL3 e a transferência desses ésteres foi maior a partir da HDL2 para a LDL e VLDL. Estes resultados indicam que a esterificação do colesterol pela LCAT é inibida nas partículas de HDL enriquecidas com óxidos de colesterol e que os ésteres de óxidos de colesterol são eficientemente transferidos para a LDL e VLDL. Portanto, sugere-se que os óxidos de colesterol exercem parte de seu efeito aterogênico pela inibição da esterificação do colesterol na superfície da HDL, causando um distúrbio no transporte reverso do colesterol, além de aumentar o potencial aterogênico da LDL e VLDL.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Using Random Amplified Polymorphic DNA to Assess Genetic Diversity and Structure of Natural Calophyllum brasiliense

The objective of this study was to assess the genetic variability in two natural populations of Calophyllum brasiliense located along two different rivers in the state of Minas Gerais, Brazil, using RAPD molecular markers. Eighty-two polymorphic fragments were amplified using 27 primers. The values obtained for Shannon index (I) were 0.513 and 0.530 for the populations located on the margins of the Rio Grande and Rio das Mortes, respectively, demonstrating the high genetic diversity in the studied populations. Nei’s genetic diversity (He) was 0.341 for the Rio Grande population and 0.357 for the Rio das Mortes population. These results were not significantly different between populations and suggest a large proportion of heterozygote individuals within both populations. AMOVA showed that 70.42% of the genetic variability is found within populations and 29.58% is found among populations (ФST=0.2958). The analysis of kinship coefficients detected the existence of family structures in both populations. Average kinship coefficients between neighboring individuals were 0.053 (P<0.001) in Rio das Mortes and 0.040 (P<0.001) in Rio Grande. This could be due to restricted pollen and seed dispersal and the history of anthropogenic disturbance in the area. These factors are likely to contribute to the relatedness observed among these genotypes

Diversidade genética de duas espécies de Eucalyptus usando marcadores ISSR

Here, we deployed a genetic diversity analysis using ISSR markers in two Eucalyptus species, as a fundamental step toward breeding strategies. The selected species were Eucalyptus urophylla and Eucalyptus microcorys, both with economic potential in forestry. The studied individuals belong to a species and the provenance test that was installed in 1974 and until now remains exempt from silvicultural treatments. Nine universal ISSR primers were used in the analyses. Intra and interspecific variation through the polymorphism percentage, polymorphism information content (PIC) and Euclidean distances among individuals were computed. The Euclidean distance among the individuals was used to perform a principal coordinate analysis (PCoA), as well as the permutation analysis of multivariate dispersion (PermDisp), followed by the Tukey’s test. A high percentage of polymorphic bands were detected, with 57.14% for Eucalyptus microcorys and 80.95% for Eucalyptus urophylla. PIC values were higher than 0.5 for four primers (UBC827, UBC835, UBC841, and UBC842). The genetic variability was significantly higher within the Eucalyptus urophylla population than in Eucalyptus microcorys, which may be associated with the greater ability of Eucalyptus urophylla to naturally hybridize, therefore, enabling the introduction of new alleles to their populations. Visando fornecer informações que sirvam de base para estudos de melhoramento genético de Eucalyptus foi realizada a análise da diversidade genética usando marcadores ISSR. As espécies estudadas foram Eucalyptus urophylla e Eucalyptus microcorys, ambas com potencial econômico florestal. Os indivíduos estudados pertencem a um teste de espécies e procedências instalado no ano de 1974 e permanecem isentos de tratos silviculturais. Para as análises foram utilizados nove primers ISSR universais. A partir dos resultados avaliou-se a existência de variação intra e interespecífica por meio da porcentagem de polimorfismo, conteúdo de informação polimórfica (PIC) e distância Euclidiana entre indivíduos. A fim de analisar a distância Euclidiana entre os indivíduos foram feitas a análise de coordenadas principais (PCoA) e análise permutacional de dispersão multivariada (PermDisp) seguida pelo teste de Tukey. Observouse elevada porcentagem de polimorfismo (57,14% para Eucalyptus microcorys e 80,95% para Eucalyptus urophylla). Considerando todos os grupos avaliados, os valores de PIC foram superiores a 0,5 para quatro primers (UBC827, UBC835, UBC841). A variabilidade interna foi significativamente maior na população de Eucalyptus urophylla em relação à Eucalyptus microcorys, o que pode estar associado à maior capacidade do Eucalyptus urophylla em hibridizar naturalmente

CLONAL MICROPLANT PRODUCTION, MORPHOLOGICAL EVALUATION AND GENETIC STABILITY OF Dendrocalamus asper (Schult. & Schult.) Backer ex. K. Heyneke

ABSTRACT: Bamboo species have many commercial applications, considering that homogeneous plantations (formed from clonal plants) are essential to high sustainable biomass production. The cloning of selected plants on an industrial scale through in vitro cultivation has many advantages, being important for the supply of plants in sufficient quantity and quality to meet commercial demand. The control of the cloning is the basis for an industrial scale, and its knowledge can optimize the process. This work aimed to evaluate the cloning of Dendrocalamus asper selected plant through micropropagation. Morphological features by scanning electron microscopy and genetic stability with ISSR molecular markers were evaluated. Four times of immersion in sodium hypochlorite (NaOCl) on in vitro establishment of nodal segments were evaluated. The established explants were transferred to a culture medium that was supplemented with three concentrations of 6-benzylaminopurine (BAP). Three concentrations of indole-3-butyric acid (IBA) to the in vitro adventitious rooting were evaluated. NaOCl application for 10 min resulted in 71.4 % of establishment in 30 d. Supplementation of the culture medium with 2.0 and 3.0 mg L-1 BAP de resulted in the highest averages for multiplication and elongation stages. The formation of adventitious roots occurred with 4.0 mg L-1 IBA of supplementation. Micropropagated plants showed normal morphological features and genetic stability, confirming the cloning of selected plant. Keywords: bamboo; micropropagation; vegetative propagation; In vitro culture; ISSR; plant growth regulator.   Produção de microplantas clonais, avaliação morfofisiológica e estabilidade genética de Dendrocalamus asper (Schult. &amp; Schult.) Backer ex. K. Heyneke   RESUMO: Espécies de bambus apresentam diversas aplicações comerciais, visto que os plantios homogêneos (formados a partir de plantas clonais) são essenciais para a alta produção de biomassa sustentável. A clonagem de plantas selecionadas em escala industrial por meio do cultivo in vitro apresenta muitas vantagens, sendo uma importante ferramenta para o fornecimento de plantas em quantidade e qualidade suficientes para atender a demanda comercial. O controle da clonagem é a base para escala industrial, e seu conhecimento pode otimizar os processos. O trabalho teve como objetivo avaliar a clonagem de planta selecionada de Dendrocalamus asper por meio da técnica de micropropagação. Foram avaliadas as características morfológicas por microscopia eletrônica de varredura e estabilidade genética por meio de marcadores moleculares ISSR. Além disso, foram avaliados quatro tempos de imersão em hipoclorito de sódio (NaOCl) no estabelecimento in vitro de segmentos nodais. Os explantes estabelecidos foram transferidos para um meio de cultura que foi suplementado com três concentrações de benzilaminopurina (BAP). Por fim, foram avaliadas três concentrações de ácido indolbutírico (AIB) durante o enraizamento adventício in vitro. A adição de NaOCl por 10 min resultou em 71,4 % de estabelecimento em 30 d. A suplementação do meio de cultura com 2,0 e 3,0 mg L-1 BAP resultou nas maiores médias para as fases de multiplicação e alongamento. A formação de raízes adventícias ocorreu com a suplementação de 4,0 mg L-1 de AIB. Plantas micropropagadas apresentaram características morfológicas normais e estabilidade genética, confirmando a clonagem da planta selecionada. Palavras-chave: bambu; micropropagação; propagação vegetativa; cultivo in vitro; ISSR; regulador de crescimento vegetal.ABSTRACT: Bamboo species have many commercial applications, considering that homogeneous plantations (formed from clonal plants) are essential to high sustainable biomass production. The cloning of selected plants on an industrial scale through in vitro cultivation has many advantages, being important for the supply of plants in sufficient quantity and quality to meet commercial demand. The control of the cloning is the basis for an industrial scale, and its knowledge can optimize the process. This work aimed to evaluate the cloning of Dendrocalamus asper selected plant through micropropagation. Morphological features by scanning electron microscopy and genetic stability with ISSR molecular markers were evaluated. Four times of immersion in sodium hypochlorite (NaOCl) on in vitro establishment of nodal segments were evaluated. The established explants were transferred to a culture medium that was supplemented with three concentrations of 6-benzylaminopurine (BAP). Three concentrations of indole-3-butyric acid (IBA) to the in vitro adventitious rooting were evaluated. NaOCl application for 10 min resulted in 71.4 % of establishment in 30 d. Supplementation of the culture medium with 2.0 and 3.0 mg L-1 BAP de resulted in the highest averages for multiplication and elongation stages. The formation of adventitious roots occurred with 4.0 mg L-1 IBA of supplementation. Micropropagated plants showed normal morphological features and genetic stability, confirming the cloning of selected plant. Keywords: bamboo; micropropagation; vegetative propagation; In vitro culture; ISSR; plant growth regulator.   Produção de microplantas clonais, avaliação morfofisiológica e estabilidade genética de Dendrocalamus asper (Schult. &amp; Schult.) Backer ex. K. Heyneke   RESUMO: Espécies de bambus apresentam diversas aplicações comerciais, visto que os plantios homogêneos (formados a partir de plantas clonais) são essenciais para a alta produção de biomassa sustentável. A clonagem de plantas selecionadas em escala industrial por meio do cultivo in vitro apresenta muitas vantagens, sendo uma importante ferramenta para o fornecimento de plantas em quantidade e qualidade suficientes para atender a demanda comercial. O controle da clonagem é a base para escala industrial, e seu conhecimento pode otimizar os processos. O trabalho teve como objetivo avaliar a clonagem de planta selecionada de Dendrocalamus asper por meio da técnica de micropropagação. Foram avaliadas as características morfológicas por microscopia eletrônica de varredura e estabilidade genética por meio de marcadores moleculares ISSR. Além disso, foram avaliados quatro tempos de imersão em hipoclorito de sódio (NaOCl) no estabelecimento in vitro de segmentos nodais. Os explantes estabelecidos foram transferidos para um meio de cultura que foi suplementado com três concentrações de benzilaminopurina (BAP). Por fim, foram avaliadas três concentrações de ácido indolbutírico (AIB) durante o enraizamento adventício in vitro. A adição de NaOCl por 10 min resultou em 71,4 % de estabelecimento em 30 d. A suplementação do meio de cultura com 2,0 e 3,0 mg L-1 BAP resultou nas maiores médias para as fases de multiplicação e alongamento. A formação de raízes adventícias ocorreu com a suplementação de 4,0 mg L-1 de AIB. Plantas micropropagadas apresentaram características morfológicas normais e estabilidade genética, confirmando a clonagem da planta selecionada. Palavras-chave: bambu; micropropagação; propagação vegetativa; cultivo in vitro; ISSR; regulador de crescimento vegetal

Proteins and isozymes electroforesis in seeds of Copaifera Langsdorffii Desf. (leguminosae caesalpinioideae) artificially aged

Electrophoresis has been used to aid the evaluation of physiological seed quality of forest species, as isozymes provide fast responses. Seeds of copaiba (Copaifera langsdorffii) were artificially aged for 0, 24, 48, 72 and 96 hours, in a germination chamber (42º C and 100% UR). The objective of this research was to evaluate possible changes in the electrophoretic patterns of proteins and isozymes during the artificial aging. The artificial aging reduced the germination and vigor of C. langsdorffii seeds, but vigor was affected faster than germination. The electrophoretic patterns showed no difference in the content of soluble and storage proteins, but for esterase and peroxidase isozymes there was reduction in the activity with aging.A eletroforese vem sendo utilizada com a finalidade de auxiliar a avaliação da qualidade fisiológica de sementes de espécies florestais, uma vez que respostas mais rápidas podem ser obtidas usando-se marcadores isoenzimáticos. Sementes de copaíba (Copaifera langsdorffii) foram submetidas a diferentes tempos de envelhecimento artificial (0, 24, 48, 72 e 96 horas), em germinador (42 ºC e 100% de UR), tendo como objetivo avaliar as possíveis mudanças nos padrões eletroforéticos de proteínas e isoenzimas, decorrentes do envelhecimento artificial. O envelhecimento artificial ocasionou redução na germinação e vigor de sementes de C. langsdorffii, sendo o vigor afetado mais rapidamente. Em relação aos padrões eletroforéticos, não houve diferença significativa no conteúdo de proteínas solúveis e de armazenamento, mas, nas enzimas esterase e peroxidase, verificou-se redução na atividade destas, à medida que as sementes foram envelhecidas.Viços

Variação genética entre e dentro de populações de candeia (Eremanthus erythropappus (DC.) MacLeish).

Among the suitable species for restoration of arboreal vegetation in degraded lands in the south of Minas Gerais, candeia trees (Eremanthus erythropappus (DC.) MacLeish) stand out because they occur and regenerate naturally in stony and poor sites. Besides, they have good attributes related to the natural durability of wood and the quality of essential oil for use in pharmacology. The success of restoration is related to the speed with which the vegetation is reestablished. Hence, the search for superior and adapted genotypes, which are able to colonize the area quickly, is of great economical and environmental importance. Open-pollinated seeds were collected from 27 mother trees in two distinct populations: São Tomé das Letras and Carrancas, Minas Gerais state, Brazil. The germinated plantlets were arranged in a randomized block design with three replications containing seedling from the 27 open-pollinated progenies. After three months of seedling grown in containers, the genetic variation among and within seed populations was evaluated. The analyses of variance showed that there were significant differences among and within populations in stem diameter. Within São Tomé das Letras population, the variation among progenies was significant in diameter and, within Carrancas population, only in seedling height the variation was significant. However, a longer term of evaluation is required for the sake of genotype selection of candeia, since a large extent of the manifested variation in seedlings stage might be due to inheritance of maternal influences that will not be transmitted for the following generations.Entre as espécies indicadas para a restauração da vegetação arbórea em sítios degradados no sul de Minas Gerais, destaca-se a candeia (Eremanthus erythropappus (DC.) MacLeish), que ocorre naturalmente em solos pobres e pedregosos, além de possuir atributos relativos à durabilidade natural da madeira e à qualidade de óleo essencial para uso na farmacologia. O sucesso da recuperação dessas áreas está relacionado com a rapidez com que a vegetação é restabelecida. Assim, a busca de genótipos superiores e adaptados, que possam rapidamente recolonizar a área, é de grande importância econômica e ambiental. Neste estudo, foram coletadas sementes de polinização livre de 27 matrizes em duas populações de candeia distintas, São Tomé das Letras e Carrancas, localizadas no Estado de Minas Gerais. Após a germinação, as mudas foram repicadas para tubetes e arranjadas em blocos casualizados completos, com três repetições. Três meses após a repicagem, foi avaliada a variação entre e dentro das populações. Verificou-se, pela análise de variância, que existem diferenças significativas entre e dentro de populações para o caráter diâmetro do caule. As variações entre as progênies foram significativas dentro da população de São Tomé das Letras para o diâmetro, e, dentro da população de Carrancas, para o caráter altura total das mudas. Porém, para a seleção de genótipos, é necessário maior tempo de avaliação, visto que grande parte da variação apresentada na fase de mudas pode ser decorrente do efeito materno, o qual não é transmitido para a geração seguinte

Genetic characterization of Zeyheria tuberculosa progenies and evaluation for formation of a seed orchard

Zeyheria tuberculosa, a native species of Brazil known for its significant potential in silviculture and genetic improvement, holds prominence among various species. In this study, our objective was to assess the diversity, genetic structure, and feasibility of establishing a seedling seed orchard (SSO) for this species. A total of 71 progenies were collected from different locations and were used in our experiment in Ijaci - MG. We genotyped 92 individuals (nine families with eight individuals, two families with seven individuals, and one family with six individuals), specifically selecting those with the highest predicted genetic values, using ten ISSR primers. The molecular markers employed effectively detected polymorphism (PIC = 0.44). The population exhibited moderate to high genetic diversity, as evidenced by observed (AO = 2.00) and effective alleles (AE = 1.61), Nei's diversity index (H* = 0.35), and Shannon's diversity index (I* = 0.52). Molecular variance analysis indicated significant genetic differentiation between the progenies (Φst = 0.19), yet the majority of the variation was observed within them (80.1%). Employing a Bayesian approach, we identified the formation of two distinct genetic groups, further confirming the non-genetic structure of the population. These findings affirm the potential of the Z. tuberculosa progenies to contribute to the establishment of a seedling seed orchard, supporting genetic improvement strategies and the conservation of the species' genetic diversity

Evaluation of total protein, peroxidase, and nutrients measured by pXRF for the determination of tissue rejuvenation / reinvigoration of Eucalyptus microcorys

Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species, hampering clonal forestry programs. This study examined possible signatures of tissue rejuvenation/reinvigoration in different propagated materials of Eucalyptus microcorys by analyzing the total protein profile, peroxidase activity, macro-and micronutrient contents, and adventitious rooting of mini cuttings. The analyses were performed on E. microcorys shoots which were successfully obtained by seminal and grafting propagation, micropropagation with epicormic shoots, and indirect organogenesis. Among four mature trees used in the propagation, tissues from the one with the best propagation results were investigated for signs of tissue rejuvenation and/or reinvigoration. Five individuals from each technique were randomly selected and transferred to a semi-hydroponic “channel” system. After four weeks in the seedbed, the total protein, peroxidase activity, nutrient content and rooting of the minicuttings were evaluated. SDS-PAGE enabled the differentiation of leaf samples obtained by grafting from the other propagation techniques, as revealed by two distinct bands. Materials obtained by micropropagation with epicormic shoots showed the highest peroxidase activity, while those obtained by seminal propagation and from the selected mature tree showed the lowest peroxidase activity. A portable X-ray fluorescence spectroscope (pXRF) identified adequate nutrient content in most of the nutrients tested in materials obtained by seminal and grafting propagation, and by indirect organogenesis. The analysis of adventitious rooting showed that the highest rooting percentage was observed in mini cuttings from seminal propagation (75%) followed by indirect organogenesis (35%). Based on principal component analysis, it was concluded that rooting of mini cuttings from both seminal propagation and indirect organogenesis organogenesis was associated with phosphorous, sulphur, and potassium contents, which suggests a higher level of tissue rejuvenation/reinvigoration in these propagated plants. Further studies are recommended to search for other methods that present similarities with the responses to adventitious rooting in forest species and thus optimize the rescue and propagation of plants with distinct ontogenetic stages

Diversidade genética de duas espécies de Eucalyptus usando marcadores ISSR

Here, we deployed a genetic diversity analysis using ISSR markers in two Eucalyptus species, as a fundamental step toward breeding strategies. The selected species were Eucalyptus urophylla and Eucalyptus microcorys, both with economic potential in forestry. The studied individuals belong to a species and the provenance test that was installed in 1974 and until now remains exempt from silvicultural treatments. Nine universal ISSR primers were used in the analyses. Intra and interspecific variation through the polymorphism percentage, polymorphism information content (PIC) and Euclidean distances among individuals were computed. The Euclidean distance among the individuals was used to perform a principal coordinate analysis (PCoA), as well as the permutation analysis of multivariate dispersion (PermDisp), followed by the Tukey’s test. A high percentage of polymorphic bands were detected, with 57.14% for Eucalyptus microcorys and 80.95% for Eucalyptus urophylla. PIC values were higher than 0.5 for four primers (UBC827, UBC835, UBC841, and UBC842). The genetic variability was significantly higher within the Eucalyptus urophylla population than in Eucalyptus microcorys, which may be associated with the greater ability of Eucalyptus urophylla to naturally hybridize, therefore, enabling the introduction of new alleles to their populations.Visando fornecer informações que sirvam de base para estudos de melhoramento genético de Eucalyptus foi realizada a análise da diversidade genética usando marcadores ISSR. As espécies estudadas foram Eucalyptus urophylla e Eucalyptus microcorys, ambas com potencial econômico florestal. Os indivíduos estudados pertencem a um teste de espécies e procedências instalado no ano de 1974 e permanecem isentos de tratos silviculturais. Para as análises foram utilizados nove primers ISSR universais. A partir dos resultados avaliou-se a existência de variação intra e interespecífica por meio da porcentagem de polimorfismo, conteúdo de informação polimórfica (PIC) e distância Euclidiana entre indivíduos. A fim de analisar a distância Euclidiana entre os indivíduos foram feitas a análise de coordenadas principais (PCoA) e análise permutacional de dispersão multivariada (PermDisp) seguida pelo teste de Tukey. Observouse elevada porcentagem de polimorfismo (57,14% para Eucalyptus microcorys e 80,95% para Eucalyptus urophylla). Considerando todos os grupos avaliados, os valores de PIC foram superiores a 0,5 para quatro primers (UBC827, UBC835, UBC841). A variabilidade interna foi significativamente maior na população de Eucalyptus urophylla em relação à Eucalyptus microcorys, o que pode estar associado à maior capacidade do Eucalyptus urophylla em hibridizar naturalmente