rss_2.0Silvae Genetica FeedSciendo RSS Feed for Silvae Genetica Genetica Feed in the amount of pollen per male flower on<abstract> <title style='display:none'>Abstract</title> <p>It is important to evenly increase the amount of scattered pollen per clone for maintaining high genetic variation in clonal seed orchards. It is thus imperative to determine not only the number of male flowers per tree, but also the amount of pollen per male flower in each clone. In this study, the existence of annual variation on the fresh weight of male flowers (FW) and the clonal and annual variation, and ramets’ variation with the same or different tree ages on the weight of pollen per male flower (WP) were investigated using 21 <italic>Abies sachalinensis</italic> clones for 3 years. The results indicated that there were significant differences in FW and WP among clones each year and the relationships between FW and WP were linearly significant for every year. WP also showed significant annual variation, while the re was also significant variation in ramets. The clonal repeatability regarding WP was 0.37—0.47 for data obtained for 2 or 3 years and the generalized linear mixed models with the random effects of clone, year, and ramet indicated that the effect of clone more strongly affected WP than other effects. These results suggested that WP on <italic>A. sachalinensis</italic> is a trait that is considerably influenced by clonal characteristics; there is thus a need to characterize this trait in each clone when using seed orchards.</p> </abstract>ARTICLEtrue of genetic variation and the potential origin of sweet chestnut ( Mill.) stands far from its natural northern distribution edge<abstract> <title style='display:none'>Abstract</title> <p><italic>Castanea sativa</italic> Mill. is an important European tree species that has been used for timber and nut production since Greek and Roman times. In Germany, the species accounts for only a small proportion of forest stands but it is attracting increasing interest due to its possible potential for climate tolerance and resilience. However, the status of German sweet chestnut stands in terms of genetic diversity and adaptive potential is poorly investigated. We took a representative sample of 520 individuals from 13 stands in northern Germany (Mecklenburg Western Pomerania; MWP) and genotyped these at 11 genomic SSRs and EST-SSRs. In addition, we compared our data with the available literature, focusing on the possible origin of the MWP populations. The analysis of genetic structure identified three distinct genetic groups within MWP, suggesting different origins or seed mixtures of various provenances. The comparison with reference data at the EST-SSR FIR059 suggests that the MWP stands originate from the western gene pool. The genetic variation observed in most MWP stands is at approximately the same level as stands in the natural range. Therefore, these stands with high diversity seem to be particularly suitable for further production of seed and plant material in MWP. This study contributes to the understanding of the genetic diversity and origin of sweet chestnut stands outside their natural distribution in MWP. It provides valuable knowledge for the evaluation and conservation of genetic resources of this tree species, which is expected to receive more attention under warmer and drier conditions.</p> </abstract>ARTICLEtrue markers for plant variety protection of clonally propagated forest trees: a case study in teak ( L.f.)<abstract> <title style='display:none'>Abstract</title> <p>Forest trees cultivars developed by breeders have been increasingly deployed as clones, following long generations of breeding and testing. An established protocol for distinctiveness, uniformity and stability (DUS) testing becomes an essential element for protecting the intellectual property rights associated with these clones. DUS testing with morphological descriptors has, however, shown limitations in categorically distinguishing cultivars, especially with narrow genetic base. DNA fingerprinting based on microsatellite markers has been a powerful tool to discriminate clones. Teak (<italic>Tectona grandis</italic>) is an economically valuable exotic timber species planted in Brazil. We assessed the individual and combined performance of a selected set of 21 teak microsatellites for identity analysis and parentage testing in a sample of 50 clones planted in Brazil. The clones displayed high genetic diversity attributable to their wide provenance origin. The 21 microsatellites combined provide high power of individual identification with a combined probability of identity of 1.84E-23 for unrelated individuals, and 4.82E-09 for full-sibs, and a power of paternity exclusion higher than 99.99999 % in all testing scenarios. Variable subsets of these 21 markers still provide abundant power of discrimination, although a recommended set should include a minimum of 12 markers with higher information content and reliable genotyping performance. Relatedness and genetic distance analyses revealed unexpected identities or significant recent shared ancestry among otherwise considered unique clones. These results advocate for the importance of including DNA markers, at least as discretionary complementary descriptors to the 22 morphological traits currently adopted for plant variety protection of teak cultivars in Brazil.</p> </abstract>ARTICLEtrue of suitable reference genes for miRNA expression normalization by quantitative RTPCR under abiotic stress in<abstract> <title style='display:none'>Abstract</title> <p>Suitable selection of endogenous controls is necessity for obtaining reliable qRT-PCR results. However, insufficient attention has been paid to the selection of endogenous controls for normalization in different stresses in plant, especially <italic>Larix olgensis</italic>. In this study, we screened candidate internal reference genes for miRNA expression normalization after subjecting <italic>Larix olgensis</italic> PEG-induced drought, NaHCO<sub>3</sub>, or NaCl stress. Needles samples were collected at 0, 12, 24, 48 and 96 h after treatment. Four common housekeeping genes and 11 mature miRNAs that were found to be stably expressed in small RNA sequencing data of <italic>Larix olgensis</italic> were selected as candidate internal reference genes. Their expression levels were assessed by qRT-PCR. GeNorm and NormFinder were used to analyse the stability of gene expression from the candidate internal reference genes. Finally, the expression of some miRNAs was analysed after stress. The results showed that miRNAs exhibited better expression stability compared to the analysed ncRNAs. Under PEG, NaHCO<sub>3</sub>, or NaCl stress, miR83321, miR43169, and miR74940 were identified as the most suitable internal reference genes, respectively. Under PEG stress, the expression of most miRNAs reached its highest level at 12 h, showing a trend of first increasing expression and then decreasing. Similarly, under NaHCO<sub>3</sub> and NaCl stress, the expression of most miRNAs reached its maximum levels at 48 h and 12 h, respectively. This indicates that most miRNAs more quickly respond to PEG and NaCl stress than NaHCO<sub>3</sub> stress.</p> </abstract>ARTICLEtrue stress-induced transcriptome changes in the context of functional interactions<abstract><title style='display:none'>Abstract</title> <p>Molecular responses to drought stress have been mainly studied in deciduous tree species although conifers dominate boreal forests. Here, we analysed the transcriptional response of <italic>Picea abies </italic>(L.) H. Karst. needles after exposure to severe drought by quantitative RNA-sequencing. In total, 2,402 differentially expressed genes (DEGs) were identified, of which 1,186 were up- and 1,216 downregulated. The upregulated DEGs are mainly involved in responses to stress, nitrogen compound, water deprivation, and abscisic acid as well as in channel activity. Although only one bZIP was identified among the DEGs, several other transcription factors involved in ABA-dependent pathways such as MYB, bHLH and WRKY showed differential expression. AP2/EREBP transcription factors related to ABA-independent pathways were also identified as DEGs. A functional interaction network of the 40 most connected <italic>Arabidopsis thaliana </italic>homologs of all <italic>Picea abies </italic>DEGs placed the two top-hubs P5CS1 and P5CS2 in the center. P5CS1 is the key enzyme in the biosynthesis of proline known to be accumulated in plants under abiotic stress. Lignin synthesis and DNA-related processes, among others, are overrepresented in this network. Our data highlight interesting gene targets for functional studies and natural genetic variation analyses to support the future identification and selection of potential drought tolerant trees.</p> </abstract>ARTICLEtrue of growth and wood traits in standing trees of the third-generation families in Indonesia<abstract> <title style='display:none'>Abstract</title> <p>The breeding of a fast-growing tree species, <italic>Acacia mangium</italic> Willd. has entered the third-generation cycle in Indonesia. To fulfill timber industry needs, wood traits, as well as growth traits, should be improved by conducting appropriate tree breeding programs for this species. In the present study, growth and wood traits were measured for the 10-year-old third-generation <italic>A. mangium</italic> from 40 half-sib families originating from four sub-lines from two provenances. The mean values of ten families in each sub-line ranged from 17.7 to 21.8 cm for stem diameter, 14.3 to 16.2 m for tree height, 3.60 to 3.77 km/s for stress-wave velocity, and 19.9 to 20.9 mm for Pilodyn penetration, respectively. The broad-sense heritability values in each sub-line ranged from 0.014 to 0.444 for stem diameter, 0.000 to 0.208 for tree height, 0.261 to 0.715 for stress-wave velocity, and 0.171 to 0.484 for Pilodyn penetration, respectively. These results suggested that families with higher density and Young’s modulus of wood, suitable for solid wood production, can be selected from the third-generation <italic>A. mangium</italic>. Stem diameter significantly correlated with the other three measured traits, while phenotypic correlation coefficients between stem diameter and stress-wave velocity or Pilodyn penetration were very low. In addition, no significant phenotypic correlations were found between other measured traits. Furthermore, positive- or non-significant genetic correlations were found between growth and wood traits in all sub-lines. Thus, it is concluded that the selection of families with good growth characteristics will not always reduce the wood properties of this species.</p> </abstract>ARTICLEtrue DNA extraction and phenolic content of salty and tannic plant material of two mangrove tree species from the mexican pacific coast<abstract> <title style='display:none'>Abstract</title> <p>Mangroves, unique tree and shrub species inhabiting coastal saline environments, exhibit distinctive ecological and morpho-physiological traits, including forming pure intertidal stands and possessing specialized mechanisms for salt excretion and aerial root respiration. These species produce valuable antioxidants, such as phenols and tannins, with significant pharmacological, ecological, and toxicological implications. This study aimed to develop a highly efficient DNA extraction protocol for mangrove leaves rich in salt and tannins. The commonly used CTAB extraction protocol and a commercial DNA extraction kit were modified to enhance DNA purity and yield. The antioxidant capacity of the samples was assessed using various protocols. The results demonstrated that the modified commercial kit outperformed other methods in extracting DNA from mangrove leaves, effectively overcoming challenges associated with high salt and phenolic compounds that could impede next-generation sequencing (NGS) analysis. Furthermore, the findings revealed an inverse relationship between tannin concentration and DNA extraction yield. This study offers a valuable resource for DNA extraction protocols from tannin-rich plant materials. In conclusion, the modified commercial kit represents the most efficient and effective approach for extracting DNA from tannin-rich mangrove leaves.</p> </abstract>ARTICLEtrue diversity and structure of (Magnoliacea): A threatened species in eastern Mexico<abstract> <title style='display:none'>Abstract</title> <p>This study analyzes the diversity and genetic structure of seven natural populations of <italic>Magnolia mexicana</italic> (Yoloxóchitl), an endangered and endemic species distributed in the Mexican Sierra Madre Oriental. The objective of the analysis is to generate basic information for the development of management and conservation programs for this species. The variation and genetic structure were estimated based on 12 SSR markers. The results indicate that the expected heterozygosity was 0.63±0.02 and the allelic richness was 1.21±0.05. The analysis of molecular variance (AMOVA) showed that variation between individuals explains 49 % of the total variation, and variation within individuals explains 36 %. The technical Neighbor joining and the ordination diagram of the canonical discriminant analysis show that the populations are made up of two genetic groups mostly. By contrast with the model Bayesian grouping (obtained with the STRUCTURE program) indicated the formation the six genetics groups. Recent bottleneck effects were observed in all localities, except in Duraznillo, El Cajón, and Zapotla. The relationship between genetic and geographic distances was not significant, which rules out a structure determined by isolation; the results suggest that the diversity and genetic structure of the species are affected by local factors such as habitat fragmentation, land use change, and excessive use of the flowers and fruits of <italic>M. mexicana</italic> by the inhabitants. Therefore, it is a priority to implement management and conservation programs to guarantee their survival.</p> </abstract>ARTICLEtrue – a computer program to test genomic tools in breeding programs<abstract> <title style='display:none'>Abstract</title> <p><italic>SNPscan breeder</italic> is a software that enables the simulation of breeding programs using simulated individual whole genome data, different genetic architectures of a trait of interest, different mating designs and different selection criteria, i.e. pheno-types, breeding values from progeny tests, marker-assisted selection (MAS) and genomic selection (GS). The impact of breeding population size, mating design, selection intensity, genetic architecture, heritability and selection criteria on genetic gains, kinship, inbreeding and genetic diversity can be evaluated to optimize the breeding program. A special feature is the possibility for post-hoc analysis of different strategies to identify causal SNPs and allele effects within the frame of genome-wide association studies (GWAS). The proportion of true and false positive SNPs and the correlation of estimated and true allelic effects can be measured and the overall impact of their use for MAS on the success of the breeding program can be tested.</p> </abstract>ARTICLEtrue efficient repeat masking library for the genomic data of coconut and related trees<abstract> <title style='display:none'>Abstract</title> <p>Even though repeat masking using custom designed libraries significantly improves the genome annotation and gene prediction, such libraries for palm trees are yet to be designed and made accessible to the researchers. In this study, a repeat library was designed and validated for use in coconut and related palm genomes. Coconut genome with chromosome-level assembly was used to design independent libraries for tall and dwarf ecotypes, which were subsequently merged. Efficiency of the combined <italic>de novo</italic> library in genome annotation and gene prediction was assessed in comparison with the conventional libraries (Dfam+RepBase), using RepeatMasker. <italic>De novo</italic> library had 76.3 % efficiency in coconut genomes compared to 3.51 % in custom libraries and number of genes predicted was reduced from an average of 193,099 to 31,022. In date palm, oil pam and sago palm also, combined library gave higher repeat masking and reduced the number of genes predicted. The <italic>de novo</italic> library can be accessed at <ext-link ext-link-type="uri" xmlns:xlink="" xlink:href=""></ext-link>.</p> </abstract>ARTICLEtrue Detection and Genetic Analysis of via Genotyping-by-Sequencing<abstract> <title style='display:none'>Abstract</title> <p><italic>Chionanthus retusus</italic> is one of the well-known ornamental trees in East Asia and America. Not only its value in the market but also had the potential as a source for producing antioxidant. However, due to uncontrolled exploitation, the number of wild <italic>C. retusus</italic> in China is decreasing rapidly. The genetic study of <italic>C. retusus</italic> is limited. In order to investigate the genetic diversity and the distribution of <italic>C. retusus</italic> in China, 47 samples from 8 different provinces have been sequenced via restriction site-associated DNA sequencing (RAD-seq). Totally, 31, 402 high-quality single nucleotide polymorphisms (SNP) were obtained. According to the phylogenetic tree and the principal component analysis, the samples were divided into four populations, including 3 major populations and 1 hybrid population. Population1 were the samples from Jiangsu and Yunnan province and the Population2 were mainly from northern and northeast of China including Liaoning and Hubei province, while the Population4 were from Shandong and Henan province, which were in central China. As the admixture showed, the population3 were the offspring of the other 3 populations by hybridization. The mean heterozygosity of Chinese Fringe tree from different province is 0.42 %, with the highest heterozygosity, which is as high as 0.63 %, from Jiangsu province and the lowest heterozygosity, which is only 0.19, from Henan province. This is the first report about the genetic diversity and relationship of <italic>Chionanthus retusus</italic>, which will provide value information for further genetic study, genomic study, conservation and breeding.</p> </abstract>ARTICLEtrue fertility and heritability in strobilus production, and gene diversity of seed crops in a second-generation seed orchard of<abstract> <title style='display:none'>Abstract</title> <p>Variation of female and male strobilus production among clones over 4 consecutive years was estimated, and genetic variance, heritability, and genetic correlation in strobilus production were investigated in the second-generation seed orchard of <italic>Pinus thunbergii</italic>. This seed orchard was created with grafts selected according to the volume growth of their offspring. The production of female strobili continued to increase, whereas the production of male strobili fluctuated throughout the investigated period. The number of female strobili was highest in rich cone years, but the production of male strobili was not the same in rich or poor years. The maleness index showed a balance between female and male parents that occurred when male strobilus production was in rich or poor years. The parental balance curve for female strobilus production was closer to the expectation (i.e., more equal contribution) than that for male strobilus production in all years. The analysis of variance revealed significant differences among clones in female and male strobilus production over the four-year period. The narrow-sense heritability was higher in male strobilus production than female strobilus, implying that male strobilus production was under genetic control. The Pearson’s correlation was positive and mostly significant, indicating that female strobilus production was reflected in male strobilus production. The effective parent number was lowest in moderate and good years for cone production. The loss of gene diversity in seed crops was lower than expected based on clonal fertility variation.</p> </abstract>ARTICLEtrue diversity and mating system of in three localities along the lower Solimões River in Central Amazonia<abstract> <title style='display:none'>Abstract</title> <p><italic>Euterpe precatoria</italic> is a Neotropical palm from South and Central America and is hyperdominant in Amazonia, where it is increasingly important in the Brazilian market for açaí. Genetic diversity, population structure and mating system of <italic>E. precatoria</italic> were characterized with 10 microsatellite markers in three localities (Codajás, Manacapuru, and Manaquiri) along the lower Solimões River, Amazonas, Brazil. Leaves of 63 mature palms were collected, as well as fruits from 30 of these to analyze 20 seedlings per progeny. Genetic differentiation across localities was substantial (<italic>G</italic><sub>S</sub><sup>′</sup> = 0.304) for mature palms, suggesting that gene flow is restricted between localities due to isolation by distance. Inbreeding was significant in progenies from all populations (ranging from 0.059–0.076), but not for mature palms, suggesting selection for heterozygosity during maturation to the adult stage. The outcrossing rate was high (0.917–1.0), confirming that the species is predominantly allogamous. Matings were not random due to the occurrence of biparental inbreeding (0.021–0.079) and correlated matings (0.059–0.424), so open-pollinated progenies present mixtures of self-sibs, half-sibs, full-sibs, and self-half-sibs, resulting in mean effective population size within progenies (2.23–3.06) lower than expected for a random mating population. The mating system’s characteristics are those expected in a predominantly allogamous hyper-abundant palm and suggest that human management of these often-anthropogenic populations is unlikely to reduce genetic diversity in the short term if done <italic>in situ</italic>, as practiced by Indigenous Peoples and local communities. Intensification will require careful attention to maintain genetic diversity.</p> </abstract>ARTICLEtrue the performance on phenotypic traits of teak ( L.f.) provenances across two trial sites in Myanmar<abstract> <title style='display:none'>Abstract</title> <p>This study was conducted to examine the variation and growth performance among eight and nine provinces at age 15 years in two trial sites in Myanmar. At the Ngalaik Reserved Forest (Ngalaik RF), the survival rates of provenances ranged from 62.4 % to 80.8 %. The Kanbalu followed by the Oaktwin and Nattalin provenances had the best survival rates at 80.8 %, 79.2 %, and 77.6 % respectively. Likewise, the survival rates ranged from 25.6 % to 74.4 % at the Yenwe Reserved Forest (Yenwe RF). The Nattalin followed by the Bago and Oaktwin provenances had the best survival rates at 74.4 %, 65.6 %, and 63.2 % respectively. The differences in stem form were found to be significant at both sites, whereas 36.24 % of teak in Ngalaik RF and 20.23 % in Yenwe RF were recorded in the class of straight tree. Based on the overall assessment of traits, teak trees in the provenances of Ngalaik RF had much better traits quality than that of Yenwe RF. According to analyses, the Bago provenance was outstanding among the provenances, followed by Phyu, Nattalin, and Paukkhaung provenances at both sites. The best-performing Bago provenance likely grew 10 % betterthan the average volume at Ngalaik RF, 1.4 % more than the average at the Yenwe RF. Among all provenances at both sites, the Thabeikkyin provenance was likely to separate as the poorest one. Based on the results, the selection of mother trees (plus trees) would make a great contribution to the application of future tree improvement programs in Myanmar.</p> </abstract>ARTICLEtrue Differentiation and Identification of Polyploids in hybrids<abstract> <title style='display:none'>Abstract</title> <p><italic>Juglans</italic> is a genus of ca. 20 species divided into four sections (<italic>Rhysocaryon, Cardiocaryon, Trachycaryon</italic> and <italic>Juglans</italic>) with a broad geographic distribution which is known for producing edible nuts and high-quality wood. Hybrid <italic>Juglans</italic> trees are becoming increasingly popular for forestry purposes in Europe because of their fast growth and adaptability. In this work, DNA was isolated from leaves of eighty-five individuals of <italic>Juglans</italic> species and hybrids and evaluated at eight nSSR and seven EST-SSR markers. The markers were able to differentiate all trees on an individual basis, and further, gave indications of polyploidy in some samples. Consequently, fifty-nine samples were then checked for ploidy by flow cytometry. Genetic structure of the population was evaluated with the most probable number of groups being K=3, which agrees with the four sections of the genus <italic>Juglans</italic>, where <italic>Cardiocaryon</italic> and <italic>Trachycaryon</italic> are genetically very similar and thus comprise one group. These results agree with other research using SSRs in <italic>Juglans</italic>. Flow cytometry revealed thirteen triploid individuals, where twelve are in agreement with the marker study, one was only detected by flow cytometry.</p> </abstract>ARTICLEtrue crosses in III. Variation and inheritance patterns in nursery trials<abstract> <title style='display:none'>Abstract</title> <p>The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in Norway. Nursery trials were performed with the families from these crosses and families from seeds collected from open pollination. Traits measured and analysed are seed weight, germination rate, germination percentage, terminal bud set, and seedling heights the first and second years. The seedlings from the population at origin 500 m had lower seed weight, lower heights and earlier bud set than those from the two populations from lower altitude. A considerable variation was present among families within each diallel, and the GCA variance components had the highest values and were significant for most traits. Variance components for SCA and maternal effects were also significant for some traits, but with inconsistent values in the three diallels. A strong relationship was present between the weight of the seed lots from the maternal parent and mean family height after one and two growing seasons. The highest estimate of heritability was observed for bud set, with similar values in all three diallels.</p> </abstract>ARTICLEtrue crosses in IV. Genetic variation and inheritance patterns in short-term trials<abstract> <title style='display:none'>Abstract</title> <p>The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in southern Norway. Seedlings from families from the diallels and open pollinations were tested in short-term tests on agricultural soil at one site at altitude 85 m until age 10 years from seed. Tree height at ages 7 and 10 years and diameter at age 10 had strongly significant GCA variance components within each population. The components for SCA and maternal effects were small and not significant, indicating low levels of non-additive genetic variation. For the days of initiation and cessation of the shoot elongation period the GCA components were dominating and had the highest heritability estimates in two of the diallels. Estimates of genetic correlations between traits measured in earlier nursery trials and height and diameter in the short-term trials had low and not consistent values in the three diallels. The duration of the shoot growth period and rate of growth showed positive relationships with height and diameter. Strong relationships were present between half-sib family means from the diallels and open-pollinated families for height, diameter and phenology traits. Progeny trials testing open-pollinated half-sib families from natural populations can be used for selection of candidates for the initial breeding populations.</p> </abstract>ARTICLEtrue growth performance and genetic parameters on Korean pine in Northeastern China<abstract> <title style='display:none'>Abstract</title> <p>Korean pine (<italic>Pinus koraiensis</italic>) is an economically valuable species owing to its excellent timber quality and nuts useful for various purposes. But few studies have been made on growth performance, and aspects combining the genetic gain and classification method on phenotypic similarity in the selection process of superior families. Thus, the present study aimed at analyzing the genetic variation and highlight suitable morphological traits for family selection; establishing trait correlations and families’ ordination based on similarities in phenotypic characters, and selecting elite families and suitable parent trees. Full-sib families from 28 crosses established in randomized complete block design from Naozhi orchard in Northeast China were used, and 11 morphological traits were investigated. Significant differences were observed among families for all traits. The traits coefficients of variation ranged from 6.07 to 56.25 % and from 0.029 to 15.213 % in phenotype and genotypic variation, respectively. A moderate level of inherited genetic control was observed (broad sense heritability H<sub>2</sub>, varied from 0.155 to 0.438). Traits related to stem growth were highly positively correlated to each other whereas crown traits showed a weak correlation with stem traits (Pearson correlation r, ranged from -0.161 to 0.956). Based on multi-trait comprehensive analysis, we selected six elite families and six parents, which resulted in a genetic gain of 5.6 %, 16.9 %, and 36.4 % in tree height, diameter at breast height, and volume, respectively. These results make a theoretical basis for selecting excellent families and establish orchards of Korean pine from improved seeds.</p> </abstract>ARTICLEtrue or non-conservative strategy to advance breeding generation? A case study in using spatial variation and competition model<abstract> <title style='display:none'>Abstract</title> <p>The greatest challenge faced when breeding populations of forest species is to achieve the right equilibrium among genetic gain and no loss of the effective population size. Thus this study aims to define the best thinning strategy to compose a seed orchard of <italic>Eucalyptus benthamii</italic> to obtain genetic gain maintaining the effective population size. The population of <italic>E. benthamii</italic> studied consisted of 28 open-pollinated progenies. The diameter at breast height (DBH) and height (H) parameters were determined three years after planting. Measurement data were analyzed and compared using four different mathematical models (with and without competition effect and spatial variation). Strategies considering genetic gain and effective population size were simulated considering the number of families, the number of individuals between families, and the total number of individuals. The mathematical model accounting for the competition effect had the best fit for DBH whereas the model accounting for the environmental variation effect presented the best fit for H. The ranking of BLUPs grouped the families into three clusters (best, intermediate/average, worst/poor families). The strategy that maintains 40 % of the individuals, generates a genetic gain of 13 % in DBH and 8 % in total height while maintaining an effective population size greater than 92 for booth traits.</p> </abstract>ARTICLEtrue the gene pools of Cypriot oaks: no evidence of intersectional hybridization<abstract> <title style='display:none'>Abstract</title> <p>In our study, we performed a population genetic analysis in all three native oak species of Cyprus and addressed whether two intermediate individuals arose from intersectional hybridization between <italic>Quercus coccifera</italic> ssp. <italic>calliprinos</italic> and <italic>Q. infectoria</italic> ssp. <italic>veneris</italic>. For this purpose, we successfully tested chloroplast and nuclear microsatellites initially developed for other oak species. We identified a set of markers that can be efficiently used for species identification and study of hybridization. Haplotypes based on the chloroplast microsatellites could resolve different maternal lineages and distinguish between the two sections represented in the study area. Using the nuclear microsatellites, we described patterns of genetic diversity across species with the endemic <italic>Q. alnifolia</italic> exhibiting reduced genetic diversity. Additionally, we employed a multivariate analysis, which could clearly differentiate among the three species. The two intermediate individuals clustered within the point cloud of <italic>Q. infectoria</italic> ssp. <italic>veneris</italic> and also possessed a chloroplast haplotype typical for this species. Therefore, we rejected the hypothesis of intersectional hybridization and interpreted their phenotypic appearance as the result of high phenotypic plasticity within <italic>Q. infectoria</italic> ssp. <italic>veneris</italic>.</p> </abstract>ARTICLEtrue