bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Variation and Correlations between Growth and Wood Density of Calycophyllum spruceanum at an Early Age in the Peruvian Amazon
Authors: Montes Sotelo , Hernández R. E. , Beaulieu J. , Weber J. C. 
Published: October 2017

AbstractCalycophyllum spruceanum (Benth.) Hook. f. ex K. Shum. is an important timber-tree species in the Peruvian Amazon Basin. As farmers and industry often use wood from young trees, it is important to investigate variation in juvenile wood properties in this species. A provenance/progeny test was established to evaluate genetic variation in growth and wood properties of young trees, the strength of their genetic control as well as their interrelationships both at the genetic and the phenotypic level in different planting zones. In this paper, results are presented for tree height and stem diameter (near ground level) at 16, 28 and 39 months; and stem diameter and basic density of the wood at breast height at 39 months. Significant variation due to provenances and especially due to families within provenances was found in growth and wood density. Phenotypic and genetic correlations indicated that larger trees tended to have denser wood. Wood density had higher heritability than height and diameter; and genetic control over height, diameter and density was generally highest in the planting zone where trees grew most rapidly.
Construction of Microsatellite Linkage Maps for Corymbia
Authors: Shepherd M. , Kasem S. , Lee D. , Henry R. 
Published: October 2017

AbstractThe genus Corymbia is closely related to the genus Eucalyptus, and like Eucalyptus contains tree species that are important for sub-tropical forestry. Corymbia’s close relationship with Eucalyptus suggests genetic studies in Corymbia should benefit from transfer of genetic information from its more intensively studied relatives. Here we report a genetic map for Corymbia spp. based on microsatellite markers identified de novo in Corymbia sp or transferred from Eucalyptus. A framework consensus map was generated from an outbred F2population (n = 90) created by crossing two unrelated Corymbia torelliana × C. citriodora subsp. variegata F1trees. The map had a total length of 367 cM (Kosambi) and was composed of 46 microsatellite markers distributed across 13 linkage groups (LOD 3). A high proportion of Eucalyptus microsatellites (90%) transferred to Corymbia. Comparative analysis between the Corymbia map and a published Eucalyptus map identified eight homeologous linkage groups in Corymbia with 13 markers mapping on one or both maps. Further comparative analysis was limited by low power to detect linkage due to low genome coverage in Corymbia, however, there was no convincing evidence for chromosomal structural differences because instances of non-synteny were associated with large distances on the Eucalyptus map. Segregation distortion was primarily restricted to a single linkage group and due to a deficit of hybrid genotypes, suggesting that hybrid inviability was one factor shaping the genetic composition of the F2population in this inter-subgeneric hybrid. The conservation of microsatellite loci and synteny between Corymbia and Eucalyptus suggests there will be substantial value in exchanging information between the two groups.
Engineering Forest Trees with Heavy Metal Resistance Genes
Authors: Merkle Scott A. 
Published: October 2017

Abstract
Pollution of soil and water with heavy metals such as mercury, cadmium and arsenic, is a worldwide problem. Phytoremediation, the use of plants to remove, sequester or detoxify pollutants, including heavy metals, offers an environmentally-friendly alternative to engineering- based methods for remediation. Forest trees have multiple features that make them particularly useful for removal of toxic heavy metals, especially if they can be engineered with genes allowing them to handle high levels of these elements. Although still in its infancy, research with transgenic trees carrying genes allowing them to detoxify or sequester some heavy metals has already made promising progress. Most of the work to date has been performed using poplar species and hybrids, although other woody species could be equally as useful. Trees have been engineered with genes for the handling of mercury, cadmium, copper and arsenic following two main approaches, phytoextraction and phytotransformation/ phytovolatilizaton. In vitro studies have shown the transgenic trees to have enhanced abilities to tolerate and/or accumulate these metals, and preliminary results from field tests indicate that the trees are functioning. New combinations of genes involved in metal transport or conversion may further enhance the heavy metal remediation capabilities of the transgenic trees. Given the environmentally friendly application, forest trees engineered for phytoremediation may be some of the first transgenic forest trees approved for operational deployment.
Reduction of Lignin Content by Suppression of Expression of the LIM Domain Transcription Factor in Eucalyptus camaldulensis
Authors: Kawaoka A. , Nanto K. , Ishii K. , Ebinuma H. 
Published: October 2017

AbstractWe report a reduction of lignin content in the woody plant Eucalyptus camaldulensis by the suppression of gene expression of the LIM domain transcription factor. Previously, we identified a cDNA encoding the tobacco (Nicotiana tabacum) LIM domain transcription factor, Nt1iml, involved in lignin biosynthesis and that specifically binds to an important cis-acting element, the PALbox sequence. The orthologous Eucalyptus gene of Ntliml, namely Ecliml, was isolated from the E. camaldulensis cDNA library (84% amino acid identity). The antisense Ntliml construct with a kanamycin-resistant gene was introduced into E. camaldulensis. The transgenic Eucalyptus plants grown in the greenhouse showed decreased expression levels of severallignin biosynthesis genes, phenylalanine ammonialyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-hydroxycinnamate CoA ligase (4CL). The abnormal phenotypic changes and a 29% reduction of lignin content were observed in the line LG12, in which the transcript level of Ecliml was most1y suppressed. Ec1iml is one of the key transcription factors involved in lignin biosynthesis.
Faster Evaluation of Induced Floral Sterilit
Authors: Hoenicka H. , Nowitzki O. , Debener Th. , Fladung Matthias 
Published: October 2017

Abstract
A major concern over the use of transgenic trees is the potential for transgene dispersal through pollen and seeds. The incorporation of sterility inducing genes into transgenic lines of trees has been proposed to reduce or even avoid gene flow of transgenes into non-transgenic interbreeding species. The evaluation of strategies for the induction of sterility in transgenic forest tree species has been hindered by their long vegetative phases. In this study an early flowering 35S::Leafy poplar line was used for the faster evaluation of the sterility construct C-GPDHC::Vst1. The combination of two transgenic approaches, one to induce early flowering and a second for the induction of sterility, allowed evaluation of this sterility strategy two years after transformation. This is a very short period of time considering the long vegetative period of seven to twenty years common in forest tree species. This approach opens opportunities for the assessment of sterility mechanisms for this plant group.
Realized Gains from Block-Plot Coastal Douglas-Fir Trials in the Northern Oregon Cascades
Authors: Ye Terrance Z. , Jayawickrama K. J. S. , Clair J. B. St. 
Published: October 2017

AbstractRealized gains for coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were evaluated using data collected from 15-year-old trees from five field trials planted in large block plots in the northern Oregon Cascades. Three populations with different genetic levels (elite - high predicted gain; intermediate - moderate predicted gain; and unimproved - wild seedlot) were compared at two planting spacings (1.8 × 1.8 m and 3.6 × 3.6 m). The realized gains at age 15 averaged over both the elite and intermediate progeny were 17.2% for stand volume per hectare, 3.5% for mean height, and 4.3% for diameter, compared to predicted genetic gains of 16.0% for volume, 5.4% for height, and 6.4% for diameter. Realized and predicted gains correlated well at the family level, with an average correlation coefficient close to 0.80. The improved populations also had higher survival rate and lower stem sinuosity than the unimproved population. Strong genetic level × planting spacing interaction effects were revealed for the growth traits at age 15 using mixed model analyses. Realized gains for stand per-hectare volume and mean growth rate were at least twice as large in the elite population as in the intermediate population at the close spacing. By contrast, both populations performed similarly at the wide spacing. This indicates that the selected genetic materials responded differently to the changes of competitive environment, and realized gain trials should closely mimic operational plantations in order to provide valid estimates of realized gains. Realized gains in per-hectare volume varied greatly among test sites. No significant genetic level x site interactions were found for any traits.
Response to Selfing in Seed Set, Seedling Establishment and Nursery Growth Based on Controlled Crosses of Abies nordmanniana Clones
Authors: Nielsen Ulrik Bräuner , Hansen Ole Kim 
Published: October 2017

Abstract
Nordmann fir (Abies nordmanniana) is used for production of high value Christmas trees in short rotation. Potentially all trees are intended to be sold - no thinnings are normally applied. A high proportion of saleable trees per ha is the main key to secure economic return to the growers. Consumers demand a symmetric and rather uniform tree and, dependent on local traditions, it should be more or less dense and narrow. In Denmark, breeding of Nordmann fir and establishment of seed orchards focus on seed supply and improved Christmas tree quality - aiming at adaption and a rather uniform ideotype Christmas tree. Benefits from employing rather few clones, to maximise gain and uniformity, may potentially be counteracted by increased selfing. The objective of this study was to quantify the effect of selfing on percentage of filled seed and nursery establishment of seedlings. Inbreeding depression was seen for filled seeds (40%), growth traits (5-17%), plus mortality and axial damage (5-12 percent units). Many selfed seedlings survive and develop into marketable seedlings, although with a depression in numbers of 23-37%, or 9-12 percent units. Nursery sorting procedures can only partially reduce the number of inbred seedlings in Nordmann fir. The large variation among clones in the response to selfing indicates that knowledge of the behaviour of selfed progeny from specific clones in ‘small number seed orchards’ is of practical interest. Trade-offs between increased gain by selection of few clones and a penalty paid for increased inbreeding need further studies during a full Christmas tree rotation.
Genetic Parameters of Somatic Clones of Coastal Douglas-fir for Growth, Stem and Wood Traits at 6½ or 7½-Years in Washington and Oregon, USA
Authors: Dean Christine A. 
Published: October 2017

AbstractFive genetic tests involving 70 somatic clones of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were planted March-April 1999 in Weyerhaeuser plantations across western Washington and Oregon states, USA. Four of the tests are in the Longview and Twin Harbors regions of Washington, and one test is in Springfield, Oregon. Each test is designed as single-tree plots with 12 randomized complete-blocks. The 70 coastal Douglas-fir clones were propagated by somatic embryogenesis (SE) from two full-sib families created by crossings among three parents. Results are reported for height, diameter at breast-height (DBH) and stem volume measured at 71/2-years; and stem sinuosity, stress wave velocity (SWV) and pilodyn at 61/2-years. Withinfamily clonal heritabilities (or repeatabilities) were estimated as the ratio of the variance between-clones within- families to the overall phenotypic variance. Variance between families was not included in the numerator of the heritability equation because the 70 SE clones are from only two full-sib families. Height had a within-family clonal heritability of 0.31 ± 0.04, DBH 0.27 ± 0.04, volume 0.24 ± 0.04, stem sinuosity 0.13 ± 0.02, SWV 0.45 ± 0.04 and pilodyn 0.31 ± 0.04. The three growth traits were all closely genetically associated with clonal correlations among them of 0.86 to 0.98. Clonal performance for growth proved quite stable across tests with an overall betweentest clonal correlation of 0.80 ± 0.04 for stem volume, meaning that clone x test interactions only accounted for a minor part of the total variance. The between-test correlation was 0.79 ± 0.06 for sinuosity, 0.96 ± 0.01 SWV and 0.86 ± 0.03 for pilodyn.
Growth Characteristics, Physiological and Metabolic Responses of Teak (Tectona Grandis Linn. f.) Clones Differing in Rejuvenation Capacity Subjected to Drought Stress
Authors: Husen Azamal 
Published: October 2017

SummaryFour-year old clones (FG1 and FG11) of teak (Tectona grandis Linn. f.), differing in rejuvenation capacity were grown in glazed earthenware pots. Drought treatments were imposed by withholding water for 20 days and rewatered to the field capacity daily for 5 days and the possible role of biochemical alteration and antioxidant metabolism in conferring photosynthetic capacity was determine by measuring photosynthetic traits, cellular damage and assaying activities of the superoxide dismutase (SOD) and peroxidase (PER) enzymes. Growth, relative water content (RWC), net photosynthetic rate (Pn), stomatal conductance (gs), chlorophyll fluorescence (Fv/Fm) and chlorophyll a, b, total chlorophyll and soluble protein content decreased significantly with increasing drought treatments from 5 to 20 days. Droughtinduced stress significantly increased the carotenoids content, relative electrolyte leakage and malondialdehyde (MDA) content, and, at the same time, accumulated free proline, free amino acid and soluble sugars in both clones. After re-watered to the field capacity daily for 5 days, both clones were shown significant recovery in the studied parameters. As compared with the FG11, the FG1 clone was more tolerant to drought as indicated by higher level of antioxidant enzyme activities as well as lower MDA content and electrolyte leakage. Similarly, drought stress caused less pronounced inhibition of Pn in FG1 than in FG11 clone. After re-hydration, the recovery was relatively quicker in FG1 than in FG11 clone. FG1 clone showed significant recovery in maximum quantum yield or photochemical efficiency of PSII (Fv/Fm) after 5 days of re-watering. The FG11 compared to the FG1, the former clone was less tolerant to drought than the latter. These results demonstrated that the different physiological strategies including antioxidative enzymes employed by the FG1 and FG11 clones of T. grandis to protect photosynthetic apparatus and alleviate drought stress. Furthermore, this study also provides ideas for teak improvement programmes and may be useful in breeding or genetic engineering for their tolerance to drought stress.
Differences Between Georgian and French Wild Cherry Populations and Consequence for Wild Cherry Breeding Programmes
Authors: Santi F. , Dufour J. 
Published: October 2017

AbstractFor the first time, the diversity of wild cherry in Caucasia was sampled: 5 populations of Georgia, together with 11 French populations. 23 alleles from 7 isozyme loci were scored, among them 6 new alleles in Georgia. Though the total number of alleles was higher in Georgia (A = 2.4) than in France (A = 2.0), the diversity was higher in France (He= 0.324) than in Georgia (He= 0.284). A higher level of differentiation was found in France (Fst= 0.094) than in Georgia (Fst= 0.057), and the total Fstwas even higher (0.108). Mean pairwise distances inside the French group, the Georgian group and between the two groups were 0.054, 0.037 and 0.094, respectively. The Pearson’s correlation coefficient between genetic and geographical distances was 0.58 (p = 0.014) between France and Georgia, which indicated a moderate pattern of isolation by distance. The number of migrants after correction of size was high among the French populations (Nm= 7.6) and even higher among the four nearby Georgian populations (Nm= 32), but it was very low between the pooled French populations and the pooled Georgian populations (Nm= 0.33). Georgia in Caucasia, as an extreme country in the distribution area, can be considered as a source of neutral gene diversity for wild cherry, and thus may also be one for adaptative gene diversity we could use to increase the genetic base of our western country wild cherry breeding populations.
Genetic Parameters for Bud Flushing and Growth Characteristics of White Spruce Seedlings
Authors: Rweyongeza Deogratias M. , Yeh Francis C. , Dhir N. K. 
Published: October 2017

Abstract
We estimated heritabilities and correlations for bud flushing and growth traits of white spruce seedlings, and the correlations of seedling traits with 10- and 11- year height of the same families in the field. The seedling greenhouse experiment had a randomized complete block design with 30 replications, 58 open-pollinated families and single-tree plots. Individual tree heritability (hi
2) was 0.78 and 0.54 for 18 (H18) and 36 (H36)-week total height, respectively. The corresponding heritabilities for family means (hf
2) were 0.91 and 0.82. For root collar diameter, hi 2 were respectively, 0.61 and 0.22 at 24 and 54 weeks from germination. The corresponding hf
2 were 0.87 and 0.55. Heritability for bud flushing ranged from 0.13 to 0.46 (hi
2) and 0.44 to 0.83 (hf 2). The genetic correlation (ra) between H18 and H36 was 0.70 and that of D24 and D54 was 0.89, indicating a substantial change in family ranking in one growing season. The type B genetic correlation for H18 with field heights ranged from 0.22 to 0.30. Type B genetic correlations of field height with all other seedling traits were very low and largely negative. It can be concluded that: (1) age-age correlation of seedling height can be expected to decline drastically even in a stable environment of the greenhouse, (2) heritability for growth potential is meaningful when estimated on cumulative growth not on individual annual growth increments that are susceptible to short-term environmental variation, (3) dates of bud flushing did not influence variation in height and root collar diameter, and (4) field growth potential is better predicted by greenhouse growth potential than other morphological and shoot phenological traits.
Clonal Variation in Acorn Production and its Effect on the Effective Population Size in a Quercus acutissima Seed Orchard
Authors: Kang K. S. , Kim C. S. , El-Kassaby Y. A. 
Published: October 2017

Abstract
Acorn production was surveyed for eight consecutive years (2000-2007) in a 94-clone Sawtooth oak (Quercus acutissima) seed orchard established in 1992. Acorn production commenced in 2000 and peaked in 2005 and was characterized by a 3-4 years interval. Sixty out of the orchard’s 94 clones were consistent producers across the study period. Acorn production’s Pearson productmoment and Spearman rank correlation coefficients were significant and consistently positive over the eight years study period. Parental cumulative reproductive output, represented by parental balance curves, slightly varied among mast years and showed steady improvement (less distortion) over years. Effective population size (Np) was high in moderate and good acorn production years; however, departure from clonal equal contribution was observed throughout the study period. Parental effective population size was estimated under various scenarios of male fecundity (pollen production is: 1) proportional to clone size, 2) equal to female contribution, and 3) equal across all clones) resulted in high Np and low group co-ancestry under equal male fecundity scenario while moderate Np size and group co-ancestry were observed when male fecundity was assumed to be proportional to clone size (i.e., ramet number).
Karyotype Analysis of Alnus Mill. (Betulaceae) Species Originating From Northeastern Asia
Authors: Jun Liu , Bao-Qing Ren , Peigao Luo , Zhenglong Ren 
Published: October 2017

Abstract
Alnus Mill. (alder) is an ecologically valuable tree genus. It is essential to study its genetic makeup in order to use alder trees to their full potential. Five specimens from four Alnus species (A. mandshurica, A. pendula, A. sibirica, and A. sieboldiana), found in northeastern Asia, were subjected to karyotype analysis. The analysis showed that these tree samples could be divided into three categories based on chromosome numbers or ploidy levels: viz., 2n = (4x) = 28, 2n = (8x) = 56 and 2n = (16x) = 112. The differences in chromosome number and karyotype parameters among Alnus species and even within the same species possibly resulted from natural polyploidization. Comparing the chromosome numbers of Alnus species in China with those in Japan showed that there appear to be only two categories in China, whereas there are up to five categories in Japan. The earliest fossil records of Alnus pollen were also discovered in Japan. We conclude that the center origin of Alnus spp. is Japan rather than China.
Realized Genetic Gains in Coastal Douglas-fir in British Columbia: Implications for Growth and Yield Projections
Authors: Stoehr Michael , Bird K. , Nigh G. , Woods J. , Yanchuk A. 
Published: October 2017

AbstractRealized genetic gain trials for coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) at five different sites with four different spacings were assessed at age 12 to compare early gain predictions in growth from small plot progeny test designs to those obtained from large block designs. Seedlings from three genetic levels, i.e., local wild-stand controls (WS), a mid-gain seedlot (MG), and a top-cross seedlot (TC) were planted in 12 × 12 tree plots with two replications at spacings of 1.6 m, 2.3 m, 2.9 m and 4.0 m. Two replications of a “single-tree plot” design at 2.9 m spacing for the three genetic levels (30 trees per genetic level) were also established, to allow for more detailed comparisons between single-tree and multiple-tree plot means. Although these trials are still relatively young, trees in the closest spacing had the highest levels of mortality with the TC trees having the highest rate of survival. Height gains in the block trials ranged from 10.4% to 16.1% for MG and TC trees, respectively, and were relatively close to the predicted values; however, volume (individual tree and volume/ha) gains exceeded expectations. Effects of genetic entry on height at age 12 were highly significant, while spacing, genetic entry by spacing, and genetic entry by test site interactions were not significant. We also compared height growth over the first 12 years to growth estimated from the “Bruce height growth model” for Douglas-fir and found that on four of the five test sites our MG and TC seedlings follow the expected height growth trajectories.