• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.153-163
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• 1998

Genetic relationships of some poplars in the section Leuce, including 5 species and 11 clones of Populus alba${\times}$glandulosa, were investigated on the basis of RAPD marker analysis. Twenty-two of the 88 arbitrary 10-mer primers, showed reproducible amplification in the preliminary experiment with 6 samples, were used for PCR and generated a total of 181 RAPD markers. Genetic relationships among the analyzed samples were tested by two phenetic methods of the UPGMA and the neighbor-joining, which revealed the close genetic relationship between P. glandulosa and P. alba. And the close genetic relationship between P. glandulosa and P. davidiana was ascertained by the principal component analysis. Based on the observation of the close genetic relationship between them, it was deduced that P. glandulosa might be originated by the saltational speciation caused by the hybridization between P. alba and P. davidiana in nature.

• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.72-76
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• 1985

Populus alba ${\times}$ P. glandulosa cuttings in nursery bed were inoculated with mycelium of ectomycorrhizal fungus, Pisolithus tinctorius (Pt) to evaluate effectiveness of the fungus in growth stimulation of poplar. Pt was cultured in 1l glass bottles with vermiculite-peatmoss mixture moistened with modified Melin-Norkrans' solution. The nursery bed was arranged for microplots of $1{\times}2m$ in size and fumigated with methyl bromide before inoculation and cutting placement. Fifty cuttings were placed in each microplot and two treatments (fumigation only and fumigation plus Pt inoculation) were replicated three times. At the end of the first growing season, inoculated plants grew 19% faster in height and produced 49% more dry weight (above-ground portion) than uninoculated plants. Survival rate of inoculated cuttings was also improved by 20% over that of uninoculated cuttings. Inoculated cuttings developed abundant fine root system with golden brown zigzag tips. In the middle of September a sporocarp of Pt was produced from an inoculated plot, suggesting successful establishment of mycorrhiza between poplar and Pt fungus.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.372-380
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• 1989

The widely cultivated hybrid poplar Populus alba ${\times}$ P. glandulosa in Korea was transformed with Agrobacterium rhizogenes agropine type strain A4. Genetic transformation was confirmed by the presence of agropine. Alteration in growth rate of hairy roots was seen following changes in the dilution rate of medium and concentration of sucrose, suggesting that improved growth might be achieved by more precise manipulation of the nutrient medium. Plant regeneration occurred from transformed hairy roots on MS medium supplemented with 0.5 mg/l BAP. Transformed plantlets grown in vitro exhibited a more developed root system characterized by fast growth behavior in comparison to normal plantlets. This work demonstrates that the root transformation would be useful in improving plantlet establishment and growth through the effective root system.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.69-75
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• 2017

Dormancy-associated protein (DRM) is involved in the dormancy physiology of plants and is conserved in almost all plant species. Recent studies found that DRM genes are involved in the abiotic stress response, and characterization studies of these genes have been conducted in several plants. However, few studies have focused on DRM genes in woody plants. Therefore, in this study, cDNA coding for DRM (PagDRM1) was isolated from poplar (Populus alba ${\times}$ P. glandulosa), and its structure and expression characteristics were investigated. PagDRM1 encodes a putative protein composed of 123 amino acids, and the protein contains two conserved domains (Domain I and Domain II). PagDRM1 is present as one or two copies in the poplar genome. Its expression level was highest in the stem, followed by mature leaves, roots, and flowers. During the growth of cultured cells in suspension, PagDRM1 was highly expressed from the late-exponential phase to the stationary phase. In addition, PagDRM1 expression increased in response to drought, salt stress, and treatment with plant hormones (e.g., abscisic acid and gibberellic acid). Therefore, we suggested that PagDRM1 not only plays an important role in the induction of dormancy, but also contributes to stress tolerance in plants.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.189-195
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• 2014

Basic leucine zipper (bZIP) protein is a regulatory transcription factor that plays crucial roles in growth, development and stress response of plant. In this study, we isolated a PagbZIP1 gene that belonged to Group SE3 of bZIP from Populus alba ${\times}$ P. glandulosa, and investigated its expressional characteristics. The PagbZIP1 is 844 base pairs long and encodes a putative 144-amino-acid protein with an expected molecular mass of 16.6 kDa. The PagbZIP1 has two conserved domains including the basic and leucine zipper portions. Southern blot analysis revealed that two copies of the gene are presented in the poplar genome. PagbZIP1 was specifically expressed in the root and suspension cells. Moreover, the expression of PagbZIP1 was induced by drought, salt, cold and ABA. Therefore, our results indicated that PagbZIP1 might be expressed in response to abiotic stress through the ABA-mediated signaling pathway in poplar.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.194-200
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• 2014

Monodehydroascorbate reductase (MDHAR) is an important enzyme that plays a role in the detoxification of reactive oxygen species (ROS) by maintaining reduced pool of ascorbate through recycling the oxidized form of ascorbate. In this study, we isolated a PagMDHAR1 gene from Populus alba ${\times}$ P. glandulosa, and investigated its expression characteristics. The PagMDHAR1 cDNA encodes a putative 434 amino acids containing FAD- and NAD(P)H-binding domains. Southern blot analysis indicated that a single nuclear gene encodes this enzyme. Northern hybridization analysis revealed that PagMDHAR1 is highly expressed in both suspension cells and flower tissues, while its expression levels were enhanced by drought, salt, cold, wounding and ABA. Therefore, PagMDHAR1 might be expressed in response to abiotic stress through the ABA-mediated signaling pathway in this poplar species, suggesting that the PagMDHAR1 plays an important role in the defense mechanisms against oxidative stress.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.180-188
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• 2019

Auxin plays a crucial regulatory role in plant growth and development processes. Three major classes of auxin-responsive transcription factors controlled by the Auxin/indole-3-acetic acid (Aux/IAA), Gretchen Hagen 3 (GH3), and small auxin up RNA (SAUR) genes regulate auxin signaling. Aux/IAA, in particular, encodes short-lived nuclear proteins that accumulate rapidly in response to auxin signaling. In this study, we isolated a PagAux/IAA1 gene from poplar (Populus alba ${\times}$ P. glandulosa) and investigated its expression characteristics. The PagAux/IAA1 cDNA codes for putative 200 amino acids polypeptide containing four conserved domains and two nuclear localization signals (NLSs). Utilizing Southern blot analysis, we confirmed that a single copy of the PagAux/IAA1 gene was present in the poplar genome. The expression of this gene is specific to leaves and flowers of the poplar. PagAux/IAA1 expressed in the early exponential growth phase of cell-cultured in suspension. PagAux/IAA1 expression level reduced in drought and salt stress conditions, and the presence of plant hormones such as abscisic acid. However, expression enhanced in cold stress, cambial cell division, and presence of plant hormones such as gibberellic acid and jasmonic acid. Thus, these results suggest that PagAux/IAA1 participates in cold stress response as well as developmental processes in the poplar.

• Journal of the Korean Wood Science and Technology
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• v.20 no.1
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• pp.60-71
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• 1992

To investigate the delignification behaviour in solvolysis pulping process, Populus alba ${\times}$ glandulosa H. and Pinus Kuraiensis S. et Z. were cooked with p-cresol and vater solvent(2:8, 5:5, 8:2 v/v) at $175^{\circ}C$ for 9 cooking time levels(20, 40, 60, 80, 100, 120, 140, 160, 180, min). Pulp yield, residual lignin content, de lignification rate, decarborhydration rate were determined. Delignification behaviours were analyzed by TEM. 1. The p-cresol-water solvent cooking of P. alba ${\times}$ glandulosa showed good delignification at the solvent system which the mixture ratio of p-cresol and water were 2:8(v/v), while the cooking of P. koraiensis with the p-cresol and water mixture ratio of 5:5 was no good. 2. P. alba ${\times}$ glandulosa showed three step-delignification phenomena at the solvent system which the mixture ratio of p-cresol and water were 2:8(v/v) anti 5:5(v/v). But P. koraiensis showed a first order delignification reaction at the same mixture ratio of p-cresol and water solvent system. 3. In TEM micrograph obtained for the solvent system which the mixture ratio of p-cresol and water was 5:5(v/v), the partial delignification of the cell corner of P. alba ${\times}$ glandulosa and P. koraiensis were observed at 60min. of cooking time. Complete delignification at the cell corner of P. alba ${\times}$ glandulosa was observed at 160min. and that of P. koraiensis was observed of 180min. of cooking time. 4. In optical microscopic observation, fiber separation of P. alba ${\times}$ glandulosa occured at 120min. and that of P. koraiensis began at 140min. of cooking time. 5. At the solvent system which the mixture ratio of p-cresol and water was 5:5(v/v), middle layer on secondary wall($S_2$) and cell corner of P. alba ${\times}$ glandulosa were more selectively delignified than primary wall(P) and outer layer on secondary wall($S_1$). However P. koraiensis did not showed any difference in delignification between cell wall layers and cell corner.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.64-68
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• 1978

Thirty nine clones of ${\times}$Populus alba glandulosa were selected tentatively and planted in Hwasung in Kyunggi-do, Jinju in Kyungnam-do, Myongju in Kangweon-do. Height measurements after tree growing seasons, indicated significant differences between clones and locations. Interaction between clones and locations were not significant statistically. Among 39 clones, 65-29-19, 65-11-106, 67-47-10, 66-14-149, 64-6-44 were best performing clones. Height measurements in Hwasung Kyunggi, and Jinju Kyungnam were 3.83m, 4.02m respectively, while that in Myongju Kangweon was only 1.06m. Myongju plantation in Kangweon-do is located in altitude of 800m and its average annual temperature was $6.2^{\circ}C$. Retarded growth in this plantation is caused high altitude and low temperature of the plantation which resulted from nearly three monthes shorter growing period than two other plantations. It is also recommended that straightness of stem, branching, wood quality and insect and disease-resistance have to be considered as selection criteria along with growth performance.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.55-58
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• 1985

The anatomical diagnoses derived from the adventitious buds, the dimples, and their surroundings, which break out often in the Populus alba ${\times}$ P. glandulosa, were investigated by the light microscope. In the anatomical structure derived from the adventitious buds, the vessel seldom occured, the diameters of the cell were smaller and the wall thicknesses were thicker than those of the normal woods. The wood fibers around the adventitious buds were crooked, frequently had the septa, and the adjacent rays showed the multiple rows. The wood fibers of the dimples were extremely crooked from pith to the hark direction and the rays showed the multiple rows. The vessels in the line-like discoloration zone around the adventitious buds and the dimples formed the traumatic tyloses.