Genus Eucalyptus Research Articles

Phylogeny is a powerful tool for predicting plant biomass responses to nitrogen enrichment.

Increasing rates of anthropogenic nitrogen (N) enrichment to soils often lead to the dominance of nitrophilic plant species and reduce plant diversity in natural ecosystems. Yet, we lack a framework to predict which species will be winners or losers in soil N enrichment scenarios, a framework that current literature suggests should integrate plant phylogeny, functional tradeoffs, and nutrient co-limitation. Using a controlled fertilization experiment, we quantified biomass responses to N enrichment for 23 forest tree species within the genus Eucalyptus that are native to Tasmania, Australia. Based on previous work with these species' responses to global change factors and theory on the evolution of plant resource-use strategies, we hypothesized that (1) growth responses to N enrichment are phylogenetically structured, (2)species with more resource-acquisitive functional traits have greater growth responses to N enrichment, and (3) phosphorus (P) limits growth responses to N enrichment differentially across species, wherein P enrichment increases growth responses to N enrichment more in some species than others. We built a hierarchical Bayesian model estimating effects of functional traits (specific leaf area, specific stem density, and specific root length) and P fertilization on species' biomass responses to N, which we then compared between lineages to determine whether phylogeny explains variation in responses to N. In concordance with literature on N limitation, a majority of species responded strongly and positively to N enrichment. Mean responses ranged three-fold, from 6.21 (E.pulchella) to 16.87 (E.delegatensis) percent increases in biomass per g N·m-2 ·yr-1 added. We identified a strong difference in responses to N between two phylogenetic lineages in the Eucalyptus subgenus Symphyomyrtus, suggesting that shared ancestry explains variation in N limitation. However, our model indicated that after controlling for phylogenetic non-independence, eucalypt responses to N were not associated with functional traits (although post-hoc analyses show a phylogenetic pattern in specific root length similar to that of responses to N), nor were responses differentially limited by P. Overall, our model results suggest that phylogeny is a powerful predictor of winners and losers in anthropogenic N enrichment scenarios in Tasmanian eucalypts, which may have implications for other species.

Analysis of SSR loci and development of SSR primers in Eucalyptus

In this study, 28,691 genome sequences and 16,566 expressed sequence tags (ESTs) of Eucalyptus were derived from the GenBank database. A total of 2292 SSR loci were sought out from 1785 effective sequences. Through analyses of SSR loci information, the SSR motif length was negatively correlated with the abundance of the SSRs. In the EST sequences of Eucalyptus, triplet repeat motifs were the most abundant, and dinucleotide repeats motifs had the highest frequencies. Subsequently, 395 pairs of primers were designed based on the SSR loci. Using optimized SSR-PCR conditions, 340 pairs of primers were successfully screened, with a success rate of 86.1%. By construction of a maximum likelihood phylogenetic tree of six eucalypt species, represented by five species of the genus Eucalyptus and one of the genus Corymbia, the genetic relationships of Eucalyptus urophylla and E. camaldulensis suggested by this tree was found to differ from that suggested by traditional morphological taxonomy. The results provide insights for evaluating genetic diversity of Eucalyptus and analysis of Eucalyptus phylogenetics using SSR markers.

Seleção de genótipos de eucalipto resistentes à ferrugem (Puccinia psidii) através de parâmetros monocíclicos

RESUMO A variabilidade genética dentro do gênero Eucalyptus para resistência à doenças e a fatores abióticos estão presentes, particularmente, com a ferrugem do eucalipto (Puccinia psidii WINTER), cuja primeira medida de controle é evitar o plantio comercial de materiais suscetíveis. A busca de caracteres quantitativos da resistência pode levar a genótipos superiores com resistência mais durável. Por isso, este estudo objetivou identificar parâmetros monocíclicos de avaliação da ferrugem em eucalipto, mais proximamente relacionados à resistência genética e estabelecer um ranking com os genótipos de maior resistência à ferrugem para compor um programa de melhoramento genético, além de relacionar a resposta do hospedeiro às vias metabólicas de defesa. Para tanto, foi realizado um estudo comparativo entre a avaliação da ferrugem no campo, com auxilio de escala qualitativa de severidade da doença com parâmetros monocíclicos quantitativos da doença em ambiente controlado. O predomínio de indivíduos suscetíveis indicou possíveis distorções de segregação nos cruzamentos, corroborando com hipóteses de estudos anteriores. Os resultados demonstraram, que o gene de resistência presente nesta população é dependente da ação de outros genes indiretamente relacionados à resistência e que participam das vias metabólicas de defesa das plantas.

Eucalyptus sp. at the Intersection of Environment and Culture in Kenya

Members of the genus Eucalyptus are popular on small farms throughout Kenya, and include species such as Eucalyptus saligna, Eucalpytus globulus, and Eucalyptus grandis. Although they are fast-growing and perform well on marginal land, these trees are associated with negative environmental effects in Africa and elsewhere they have been introduced. In-person surveys were conducted with small farmers in Kenya to determine patterns of Eucalyptus sp. stand use and cultural importance. It was found that despite acknowledged short and long term environmental consequences, Eucalyptus sp. remains popular for medium term economic investment. These findings are consistent with other reports of Eucalyptus sp. woodlots serving as funding sources for education, health emergencies, etc., in parts of the world where bank loans are unavailable. Further, it was found that some farmers are using modified silviculture practices to ameliorate the negative effects of Eucalyptus sp., and others are seeking indigenous alternatives.

Medium term water deficit elicits distinct transcriptome responses in Eucalyptus species of contrasting environmental origin

BackgroundClimatic and edaphic conditions over geological timescales have generated enormous diversity of adaptive traits and high speciation within the genus Eucalyptus (L. Hér.). Eucalypt species occur from high rainfall to semi-arid zones and from the tropics to latitudes as high as 43°S. Despite several morphological and metabolomic characterizations, little is known regarding gene expression differences that underpin differences in tolerance to environmental change. Using species of contrasting taxonomy, morphology and physiology (E. globulus and E. cladocalyx), this study combines physiological characterizations with ‘second-generation’ sequencing to identify key genes involved in eucalypt responses to medium-term water limitation.ResultsOne hundred twenty Million high-quality HiSeq reads were created from 14 tissue samples in plants that had been successfully subjected to a water deficit treatment or a well-watered control. Alignment to the E. grandis genome saw 23,623 genes of which 468 exhibited differential expression (FDR < 0.01) in one or both ecotypes in response to the treatment. Further analysis identified 80 genes that demonstrated a significant species-specific response of which 74 were linked to the ‘dry’ species E. cladocalyx where 23 of these genes were uncharacterised. The majority (approximately 80%) of these differentially expressed genes, were expressed in stem tissue. Key genes that differentiated species responses were linked to photoprotection/redox balance, phytohormone/signalling, primary photosynthesis/cellular metabolism and secondary metabolism based on plant metabolic pathway network analysis.ConclusionThese results highlight a more definitive response to water deficit by a ‘dry’ climate eucalypt, particularly in stem tissue, identifying key pathways and associated genes that are responsible for the differences between ‘wet’ and ‘dry’ climate eucalypts. This knowledge provides the opportunity to further investigate and understand the mechanisms and genetic variation linked to this important environmental response that will assist with genomic efforts in managing native populations as well as in tree improvement programs under future climate scenarios.

Dual mycorrhizal symbiosis: an asset for eucalypts out of Australia?

The dual symbiotic habit of the genus Eucalyptus is well documented: while arbuscular mycorrhizae are always dominant in seedlings and young trees, they are replaced by ectomycorrhizae in older trees. Here, the mycorrhizal status of eucalypts of different ages was assessed over the year in three plantations in the humid Mediterranean climate zone of Algeria (using morphological, anatomical, and histological criteria) and quantified in the dry and wet seasons over three years (using the grid-line intersect method of Giovannetti and Mosse (1980, New Phytol. 84: 489–500, doi: 10.1111/j.1469-8137.1980.tb04556.x ) on randomized fine root segments). Unexpectedly, the results revealed the persistence of arbuscular mycorrhizae in old trees and their dominance over ectomycorrhizae during the dry season, while the opposite pattern was observed in the wet season. Composite mycorrhizae displaying intimately mixed arbuscular mycorrhizae and ectomycorrhizae anatomical structures also occurred and were more frequent during the dry season. Eucalypts were clearly able to form a wide diversity of symbiotic associations with arbuscular mycorrhizal and ectomycorrhizal fungi locally associated with native trees, shrubs, and herbaceous plants. Therefore, the mycorrhizal status should not be a limiting factor to the silviculture of eucalypts in this area of Algeria because the dual symbiotic habit provides complementary benefits in a poor soil and in an alien environment.

Microsatellite allele length variations in inter-specific hybrids of Eucalyptus

AbstractThe genus Eucalyptus encompasses several species of industrial importance. Many of these species have been subjected to genetic characterization using different kinds of DNA markers. More than 1000 microsatellites have been identified from the genome of eucalypts and they are highly amenable for cross species transferability. During cross amplification of microsatellites, homoplasy is reported in many species in which although the allele size might be the same, the sequences are not. Thus, it is essential to ascertain the DNA sequence homology with source and target microsatellite repeats. Accordingly, fifty five alleles from six microsatellite loci (ECc1, ECc2, Eg61, Embra100, Embra1468 and Embra2002) were amplified in two inter-specific hybrid populations (Eucalyptus tereticornis × E. grandis and E. tereticornis × E. camaldulensis) and sequenced. The results showed that all the microsatellite loci were amplifying the target repeat types except for the loci Eg61 and Embra2002. The locus Eg61 has target repeat of (CAA)(GAT) but the sampled alleles had either (CAA)(GAT) or (GAT) alone. Similarly, the Embra2002 locus was targeting interrupting repeats of (CCA)..(CCA), but the sequenced alleles had repeats of (CCA) with or without interruption. Nevertheless, the allele size estimated in electrophoresis for hybrids was in conformity with that of the parent alleles. This study suggests the need for validation of the repeat characteristics of microsatellites by sequencing of the alleles particularly in cross species amplification.

English

Forestry production is traditionally predicted using mathematical modelling, where whole-stand models are prominent for providing estimates of growth and production per unit area. However, there is a need to perform research that adopts innovative tools, such as artificial Intelligence techniques. The objective of this study was to train and evaluate the efficiency of Artificial Neural Networks (ANN) in the modeling process of growth and production of Whole-Stand Level, in “equineanean” forests of the Eucalyptus genus clones. For the training of the networks, the supervised method was adopted. There were 100 networks trained, of which, for each output variable, 5 networks were selected. The criteria used to verify the quality of the training and validation of the networks were: Student's test “T”, graphical analysis of the dispersion of residues, standard error of the relative estimate (Syx%), Pearson's correlation coefficient (r) between the observed and estimated values, ​​and aggregate difference (AD). The ANN selected in the training process, which estimated the volume variables, site index and future production, when validated did not differ statistically by the Test T and presented adequate statistical accuracy values ​​to the modeling process, with satisfactory correlation values ​​(r) between the observed and estimated values, low values ​​of standard error of the relative estimate (Syx%) and aggregate difference (AD). Artificial neural networks of the multilayer perceptron type are precise and efficient in the entire modeling process for whole-stand level of Eucalyptus plantations, therefore its use is recommended. Key words: Artificial intelligence, prognosis, site classification, Brazil.

Differential behaviours in two species of Eucalyptus exposed to aluminium

One of the limiting factors in the growth and development of plants is soil acidity due to high aluminium (Al) content. The aim of this research was to determine the micronutrient contents, photosynthetic pigments, gas exchange and morphological parameters, and to explain the possible tolerance mechanisms involved in two species of the genus Eucalyptus that were exposed to low and high aluminium concentrations. The experiment was conducted in a factorial completely randomised design, with two aluminium concentrations, viz., 0.08 (low) and 1.60 (high) mM Al, and two species, i.e., Eucalyptus platyphylla and Eucalyptus grandis. High Al concentration increased the Al contents in E. platyphylla and E. grandis by 104 and 29%, respectively. Significant reductions of Fe, Zn and Mn contents were detected only in E. platyphylla. Reductions on chlorophyll b and total chlorophyll were observed in both the species, which were more intense in the E. platyphylla. Net photosynthetic rate and water use efficiency increased under high Al concentration, whereas stomatal conductance and transpiration rate decreased in E. grandis. Growth characteristics decreased under high Al concentration in E. platyphylla and increased in E. grandis, while opposite response was observed in both species under low Al concentration. Our results described clearly that E. platyphylla is sensitive, while E. grandis is tolerant to Al. The tolerance mechanism of E. grandis can be explained by the maintenance of the iron, zinc and manganese supplies, combined with an increase in the chlorophyll a, net photosynthetic rate and water use efficiency, resulting in the mitigation of the Al effects on growth parameters.

Intra and intergeneric transferable gene-derived orthologous microsatellite markers in Eucalyptus and Corymbia species

ABSTRACTThis study describes the development and application of a novel strategy that targets repeat domains in the orthologous genic region of two Eucalyptus species to derive Expressed Sequence Tags (EST)-based functional orthologous microsatellite markers and their characterization in four Eucalyptus and two Corymbia species. About 13,468 ESTs of Eucalyptus globulus were assembled into unigenes, screened for repeat motifs and then mapped on the Eucalyptus grandis genome. The simple sequence repeat (SSR)-positive orthologous sequences of E. grandis, along with 13,380 genomic sequences of Eucalyptus camaldulensis, were then screened for di- and tri-nucleotide repeat motifs and 230 primer pairs were designed. Functional annotation was carried out through homology search and gene ontology using E. grandis transcript database. Of 230 SSRs, 179 were validated in E. camaldulensis and a subset of 20 SSRs was used for characterization and cross species/genera transferability using 130 individuals from both Eucalyptus and Corymbia. The average values of number of alleles, polymorphic information content, observed and expected heterozygosity were 10.57, 0.59, 0.43 and 0.62, respectively, in E. camaldulensis. High marker transferability within the genus Eucalyptus (up to 98%) and Corymbia (up to 80%) was observed.

EUCANEXT: an integrated database for the exploration of genomic and transcriptomic data from Eucalyptus species.

Tree species of the genus Eucalyptus are the most valuable and widely planted hardwoods in the world. Given the economic importance of Eucalyptus trees, much effort has been made towards the generation of specimens with superior forestry properties that can deliver high-quality feedstocks, customized to the industrýs needs for both cellulosic (paper) and lignocellulosic biomass production. In line with these efforts, large sets of molecular data have been generated by several scientific groups, providing invaluable information that can be applied in the development of improved specimens. In order to fully explore the potential of available datasets, the development of a public database that provides integrated access to genomic and transcriptomic data from Eucalyptus is needed. EUCANEXT is a database that analyses and integrates publicly available Eucalyptus molecular data, such as the E. grandis genome assembly and predicted genes, ESTs from several species and digital gene expression from 26 RNA-Seq libraries. The database has been implemented in a Fedora Linux machine running MySQL and Apache, while Perl CGI was used for the web interfaces. EUCANEXT provides a user-friendly web interface for easy access and analysis of publicly available molecular data from Eucalyptus species. This integrated database allows for complex searches by gene name, keyword or sequence similarity and is publicly accessible at http://www.lge.ibi.unicamp.br/eucalyptusdb. Through EUCANEXT, users can perform complex analysis to identify genes related traits of interest using RNA-Seq libraries and tools for differential expression analysis. Moreover, all the bioinformatics pipeline here described, including the database schema and PERL scripts, are readily available and can be applied to any genomic and transcriptomic project, regardless of the organism. Database URL: http://www.lge.ibi.unicamp.br/eucalyptusdb

Ecofisiologia e crescimento de &lt;em&gt; Eucalyptus &lt;/em&gt; em condição de déficit hídrico

O objetivo desta revisão bibliográfica é apresentar alguns resultados sobre os efeitos do déficit hídrico no crescimento, produção e no comportamento ecofisiológico de espécies do gênero Eucalyptus. Vários trabalhos têm sido realizados a respeito deste tema em diferentes nações, principalmente Austrália, Espanha, Tasmânia, China e Brasil. Contudo, esta revisão busca sintetizar resultados científicos sobre os principais aspectos a respeito da eficiência do uso da água, variáveis envolvidas nas trocas gasosas e no status hídrico das plantas (condutância estomática, transpiração, potencial hídrico foliar, fotossíntese), características de crescimento e modificações morfológicas do gênero Eucalyptus sp. Em todos os trabalhos observados os tratamentos com déficit hídrico, afetaram o uso da água, ocasionaram redução na condutância estomática, transpiração, potencial hídrico foliar e fotossíntese, reduzindo consequentemente o crescimento e modificando a morfologia das espécies de Eucalyptus. Portanto, a busca por materiais genéticos tolerantes a seca pode ser relevante para o sucesso de povoamentos florestais em áreas com déficit hídrico.

Chemical Variability and Biological Activities of Eucalyptus spp. Essential Oils.

Many plant species produce mixtures of odorous and volatile compounds known as essential oils (EOs). These mixtures play important roles in Nature and have been utilized by mankind for different purposes, such as pharmaceuticals, agrochemicals, aromatherapy, and food flavorants. There are more than 3000 EOs reported in the literature, with approximately 300 in commercial use, including the EOs from Eucalyptus species. Most EOs from Eucalyptus species are rich in monoterpenes and many have found applications in pharmaceuticals, agrochemicals, food flavorants, and perfumes. Such applications are related to their diverse biological and organoleptic properties. In this study, we review the latest information concerning the chemical composition and biological activities of EOs from different species of Eucalyptus. Among the 900 species and subspecies of the Eucalyptus genus, we examined 68 species. The studies associated with these species were conducted in 27 countries. We have focused on the antimicrobial, acaricidal, insecticidal and herbicidal activities, hoping that such information will contribute to the development of research in this field. It is also intended that the information described in this study can be useful in the rationalization of the use of Eucalyptus EOs as components for pharmaceutical and agrochemical applications as well as food preservatives and flavorants.

Secondary metabolites from Eucalyptus grandis wood cultivated in Portugal, Brazil and South Africa

The composition of the lipophilic and phenolic fractions of the wood of Eucalyptus grandis cultivated in Portugal, Brazil and South Africa, was studied. The lipophilic fraction of the studied E. grandis wood is mainly composed of sterols, fatty acids and phenolic compounds. Three triterpenic acids were detected for the first time in the wood extracts from Brazil. E. grandis wood from Portugal presents the largest lipophilic content (1.67gkg−1 of dry wood), followed by South Africa (1.56gkg−1 of dry wood) and Brazil (1.05gkg−1 of dry wood). 51 Phenolic compounds were identified in E. grandis wood MeOH:H2O extracts, from which 11 are reported for the first time as E. grandis constituents and 4 phenolic compounds are firstly reported as Eucalyptus genus components. E. grandis wood from Brazil shows the highest phenolic content (∼2.36gkg−1 of dry wood), followed by South Africa (∼1.90gkg−1 of dry wood) and Portugal (∼1.30gkg−1 of dry wood), demonstrating the influence of the geographic origin over E. grandis wood extractives composition and abundance, as well as on the antioxidant activities of the phenolic fractions. The detailed knowledge of these E. grandis extracts can contribute on the one hand to prevent their impact in the bleaching process, and, on the other demonstrates the potential of this species as a source of bioactive phytochemicals for nutraceutical applications.

Caracterização tecnológica da madeira de Eucalyptus benthamii Maiden et Cambage

The knowledge about the technological properties of the wood enables the achievement of tools that assist in the adequate use of this material. Therefore, the aim of this study was accomplish the technological characterization of Eucalyptus benthamii wood for potential uses. For this, it was used six trees of the forestry plantation implanted in the Guatambu city, Santa Catarina State, Brazil. For the physical characterization of the wood, discs were obtained at three different positions of the trunk of each tree, determining the basic density and retractibility. The test pieces to the mechanical tests of parallel compression to the fibers, dynamic bending, static bending and Janka hardness were obtained from discs removed of the logs. The average basic density was 0.549 g cm-3, while the retractibility parameters were similar to those of genus eucalyptus, with an average anisotropy coefficient of 1.9, indicating that it is a specie unstable dimensionally. The results obtained from the mechanical tests show that the Eucalyptus benthamii wood has less resistant to mechanical stress, limiting its use for this purpose. Therefore, the application of this species for purposes applying mechanical stress is limited, making it necessary carrying out studies about the other properties of this wood.

Effects of forest thinning on soil-plant carbon and nitrogen dynamics

Corymbia spp. (previously included in the genus Eucalyptus) are common species in sub/tropical Australia and produce high quality timber and round logs. Thinning of native forests helps to preserve native tree species and is more sustainable than replacing native forest stands with mono-species plantations to produce timber. This study aimed to explore the effects of native forest thinning on soil-plant carbon (C) and nitrogen (N) dynamics in two experimental sites, Esk (5 years post-thinning) and Herberton (7 years post-thinning), situated in Queensland, Australia. The two sites had different thinning regimes. The final stocking rates varied between 75 and 200 stems ha−1 at Esk and between 250 and 400 stems ha−1 at Herberton. The thinned plots were compared to un-thinned plots. Soil samples were collected to measure labile C and N. Leaf samples were collected from C. variegata and C. citriodora in Esk and Herberton respectively. Thinning did not change soil total C, total N, δ15N and inorganic N at either Esk or Herberton. However, at Esk, intensive thinning resulted in decreases in water soluble total N (WSTN). Foliar δ13C did not vary with respect to thinning whereas foliar δ15N values were more enriched in thinned areas than those of un-thinned plots. The stepwise linear regression indicated that both foliar total N and δ15N were explained mainly by soil TN and WSTN. Thinning did not change soil C and N most likely due to the retention of thinned materials on site and their incorporation into soil. Foliar δ13C was not thinning-dependent due to homeostatic maintenance of the ratio of intercellular to ambient CO2 concentrations during photosynthesis. In our study, soil N was not a limiting factor for foliar N, however, foliar N was mainly driven by WSTN which may foreshadow a possible N limitation in severely thinned plots in the long term. We conclude that forest thinning does not decrease soil C and N availability in native Corymbia forests for several years post-thinning if the thinned materials are retained on site.

Phylogeny Explains Variation in The Root Chemistry of Eucalyptus Species.

Plants are dependent on their root systems for survival, and thus are defended from belowground enemies by a range of strategies, including plant secondary metabolites (PSMs). These compounds vary among species, and an understanding of this variation may provide generality in predicting the susceptibility of forest trees to belowground enemies and the quality of their organic matter input to soil. Here, we investigated phylogenetic patterns in the root chemistry of species within the genus Eucalyptus. Given the known diversity of PSMs in eucalypt foliage, we hypothesized that (i) the range and concentrations of PSMs and carbohydrates in roots vary among Eucalyptus species, and (ii) that phylogenetic relationships explain a significant component of this variation. To test for interspecific variation in root chemistry and the influence of tree phylogeny, we grew 24 Eucalyptus species representing two subgenera (Eucalyptus and Symphyomyrtus) in a common garden for two years. Fine root samples were collected from each species and analyzed for total phenolics, condensed tannins, carbohydrates, terpenes, and formylated phloroglucinol compounds. Compounds displaying significant interspecific variation were mapped onto a molecular phylogeny and tested for phylogenetic signal. Although all targeted groups of compounds were present, we found that phenolics dominated root defenses and that all phenolic traits displayed significant interspecific variation. Further, these compounds displayed a significant phylogenetic signal. Overall, our results suggest that within these representatives of genus Eucalyptus, more closely related species have more similar root chemistry, which may influence their susceptibility to belowground enemies and soil organic matter accrual.

Genetic parameters for growth and wood mechanical properties in Eucalyptus cloeziana F. Muell.

Genetic parameters for wood mechanical properties and their correlations with growth traits are not well established in the important tree genus Eucalyptus L’Her. Based on a progeny trial of 115 open-pollinated families of Eucalyptus cloeziana F. Muell., this study estimated the heritability and trait–trait correlations for growth, including height (H), diameter at breast height (D) and volume (V), and wood mechanical traits, including basic density (BD), green density (GD), modulus of elasticity (MOE), modulus of rupture (MOR) and parallel-to-grain compressive strength (σc). Narrow-sense heritability (h 2 ) ranged from 0.04 to 0.35 for growth across ages 0.5–9.5 years and from 0.06 to 0.24 for wood mechanical properties at age 9.5, indicating low to moderate magnitude of additive genetic control of these traits. Phenotypic (r p ) and additive genetic (r g ) correlations at the final age of 9.5 years were consistently significantly positive between growth traits and mostly significantly positive between wood mechanical traits, while r p and r g were small and adversely significant, respectively, between the two types of traits, posing a challenge for concomitant improvement of growth and wood traits. In addition, r p and r g coefficients between age 9.5 and earlier years for each of the growth traits H, D and V were all positively significant (except for H 2.5) and had a generally increasing trend with age, suggesting the possibility of early selection.

A novel set of EST-InDel markers in Eucalyptus L’Hérit.: polymorphisms, cross-species amplification, physical positions and genetic mapping

Insertion/deletion (InDel) markers are valuable for genetic applications in plant species, and the public databases of expressed sequence tags (ESTs) have facilitated the development of genic InDel markers. In this study, we developed a novel set of 144 InDel markers in an important tree genus Eucalyptus L’Herit. using the ESTs of GenBank. Amplicon sequencing against two parents of a mapping population (Eucalyptus urophylla S. T. Blake × E. tereticornis Smith) revealed that the InDel size ranged from 2 to 44 bases, and the dinucleotide type was the most abundant (37.3 %). The cross-species/subgenus amplification rate ranged from 62.5 % in E. tessellaris F. Muell. (subgenus Blakella) to 99.3 % in E. grandis Hill ex Maiden (subgenus Symphyomyrtus) with an average of 85.4 %. There were 121 EST-InDels (84.0 %) polymorphic among 12 individuals of E. grandis, and the mean number of alleles per polymorphic locus (N a), observed heterozygosity (H o), expected heterozygosity (H e) and polymorphic information content (PIC) were 4.0, 0.278, 0.538 and 0.465, respectively. Physical positions of 143 EST-InDels were predicted on the E. grandis genome sequence. A total of 81 EST-InDels were incorporated into prior dense genetic maps of E. urophylla and E. tereticonis, and extensive synteny and colinearity were observed between E. grandis genome sequence and the mapped EST-InDel markers. These EST-InDels will provide a valuable resource of functional markers for genetic diversity evaluation, genome comparison, QTL mapping and marker-assisted breeding in Eucalyptus.

Brief history of Eucalyptus breeding in Brazil under perspective of biometric advances

ABSTRACT: Forest breeding is a science that has been developing in Brazil since 1941 being the Eucalyptus a highlighted genus in this scenario. In a global scene, Brazil is displayed prominently in productivity of Eucalyptus planting, due to favorable environmental conditions to cultivation development, and the incentive in research for improvement of traits of interest t observed in it species and hybrids. This research included a historical review of Eucalyptus breeding over the years under genetic biometric perspective in Brazil, from reports describing the pioneer planting up to the current genome wide selection (GWS) that came as a complement of forest breeding success. This review showed some of the tracks performed by researchers aiming to improve the productive and quality of phenotypic traits from Eucalyptus genus.