• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.198-203
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• 2013

Herein we analyzed the nuclear DNA content and the histological characteristics of the triploid of the 'Hyunsasi' (Populus alba ${\times}$ P. glandulosa $F_1$) which were developed for biomass production and molecular breeding research. The flow cytometric analysis showed that the nuclear DNA content of the 3 triploids were 1.6 times greater than those of the diploid. In terms of histological characteristics, the cross-section area of the stem of 'Line-18' was 1.6 times larger than that of the diploid. The area of pith, and cortex and phloem of the stem of 'Line-18' was also 1.6 and 2.0 times larger than that of the diploid, respectively. Moreover, the length and area of guard cell of 'Line-18' was 1.2 times larger than that of the diploid. These results helps to understand the cytological characteristics of the triploid poplar clones, and further investigations in the growth rate and wood properties of the triploids growing in the field will determine whether the triploid poplars are good candidates for molecular breeding programs and for the improvement of industrial biomass productivity.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.291-296
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• 2012

Triploids are a useful tool for biomass production and molecular breeding of trees with a long life span. Triploids of the poplar 'Hyunsasi' (Populus alba ${\times}$ P. glandulosa) have been developed by crossing between female diploids and a male tetraploid. The tetraploid was developed around the 1970s at Korea Forest Research Institute by colchicine-induced chromosome doubling. Seedlings of the $F_1$ generation were analyzed using flow cytometry to verify their ploidy status. The mean relative fluorescence index of 3 F1 poplars, labeled as Line- 1, Line-17, Line-18, were approximately 1.5 times higher than those of diploid poplars, and the results clearly indicated that they were triploids. The phenotype of the F1 poplars included larger leaves and thicker stem than diploids, and abnormal leaf morphology, especially in the triploid 'Line-18'. Three triploid lines developed roots more slowly and had less roots than diploid. However, 3 poplar cytotypes (2x, Line-1, Line-17) rooted within 10 days on MS medium. In contrast, compared with the 3 cytotypes, the Line-18 showed about 80% and 70% in the rooting rate and the number of roots. The triploid poplars could be directly utilized for biomass production and with their sterility, they could serve as basic material for genetic transformation. In addition, flow cytometric analysis proved to be an effective and reliable method for screening forest trees for their ploidy level.

• Journal of Korea Foresty Energy
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• v.19 no.2
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• pp.93-101
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• 2000

Wood of Robinia pseudoacacia and bark of Populus alba$\times$P. glandulosa, Fraxinus rhynchophylla and Ulmus davidiana var. japonica were collected and extracted with acetone-water(7:3, v/v) in glass jar to examine whether its bioactive compounds exist. The concentrated extracts were fractionated with hexane, chloroform, ethylacetate and water, and then freeze-dried for column chromatography and bioactive tests. The isolated compounds were sakuranetin-5-O-$\beta$-D-glucopyranoside from Populus alba $\times$Pl glandulosa, 4--ethyoxy-(+)-leucorobinetinidin frm R. pseudoacacia and fraxetion from F. rhynchophylla and were characterized by $^1H$ and$^{13}C $ NMR and positive FAB-MS. Decay-resistant activity was expressed by weight loss ratio and hyphae growth inhibition in the wood dust agar medium inoculated wood rot fungi. R. pseudoacacia showed best anti-decaying property in both test and its methanol untreated samples, indicating higher activity than methanol treated samples in hyphae grwoth test. In antioxidative test, $\alpha$-tocopherol, one of natural antioxidants, and BHT, one of synthetic antioxidants, were used as references to cmpare with the antioxidant activities of the extacted fractions. Ethylacetate fraction of F. rhynchophylla bark indicated the hightest activity in this test and all fractions of R. pseudiacacia extractives also indicated higher activities compared with the other fractions. In the isolated compounds, aesculetin isolated from F. rhynchophylla bark showed best activity and followed by robonetinidin from R. pseudoacaica.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.105-115
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• 2000

This study was conducted to test a hypothesis that sensitivity of trees to ozone exposure was related to their growth rates. Two cultivars of Populus alba ${\times}$ P. glandulosa with different genetic growth potential were used for the comparison. Two clones(72-30, 72-16) of cultivar No. 4 with fast growing potential and three clones(71-28, 72-27, 72-19) of cultivar No. 2 with slow growing potential were propagated in early spring by cutting in $2-{\ell}$ plastic pots. They were grown outdoor for 5 months and exposed in late August for 30 days to 70 and 130ppb ozone in a open-top chambers(2.5m in diameter and 2m in height). Ozone concentration in a control chamber was maintained below 30ppb by filtering with activated charcoal. Each treatment was replicated twenty times. In a control chamber, cultivar No. 4 grew 73%, 64%, and 38% faster than cultivar No. 2 in leaf weight, root weight, and total dry weight, respectively. Visible injury was observed only in cultivar No. 4 in 130ppb treatment. Ozone treatment at both 70 and 130ppb decreased height growth, dry weight of leaf, root, and entire plants in all five clones. Particularly root growth was reduced by 39.7% and 13.8% in cultivar No. 4 and No. 2, respectively, in 70ppb treatment. Consequently, shoot/root ratio of cultivar No.4 was increased by 63.4%, while that of cultivar No.2 was increased by 22.1%. Stomatal conductance decreased more in cultivar No.4 than in cultivar No.2. Net photosynthesis of cultivar No.4 at 130ppb ozone decreased by 69.5%, while that of cultivar No.2 decreased by 31.5%. Above mentioned physiological responses of two cultivars to ozone strongly suggested that fast growing cultivar No.4 was more sensitive to ozone than slow growing cultivar No.2. It was concluded that sensitivity of trees to ozone exposure was closely related to their growth rates.

• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.195-201
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• 1986

This study was conducted to investigate the life history of Compsidia populnea which is major species of the stem-borers on Populus alba{\times}glandulosa$. Peak emergence of the adult of Compsidia populnea L. was around 10th${\sim}$l2nd of May in Chuncheon vicinities, having one generation a year in Korea. There was a preovipositional period of 10.7 days and a ovipositional period of 14.3.days. Mean adult longevity was 11 days for male and 13.8 days for female. Individual eggs were long oval with somewhat narrowed tip at one side and soft, 2.6mm in length, 0.8mm in diameter, and were laid singly under the U-shaped scars which were made by female before oviposition. Total number of scars per female averaged 56.6 ($8{\sim}135$) and eggs were found in 67.9 percent of the total scars. Egg period was $8{\sim}11$ days at $25^{\circ}C$ constant temperature and $7{\sim}14$ days in the field condition. Early young larvae stayed for $2{\sim}3$ weeks under the scars and then boring into the xylem, forming galls at this time. Size of the gall was 1.8cm($1.3{\sim}2.5$) in length, 1.6cm($1.0{\sim}2.2$) in diameter and the length of mine was everage 3.1cm. Fully grown larvae were developed around the early October and overwintered in the mines of galls. Pupation was done around the early of April. Pupal developmental period averaged 11 days($9{\sim}13$ days) at $25^{\circ}C$ constant temperature condition.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.331-337
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• 2013

Formate dehydrogenase (FDH), catalyzing the oxidation of the formate ion to carbon dioxide, is known as the stress protein in response to drought, low temperature and pathogen infection. To study the functions of FDH in poplar (Populus alba ${\times}$ P. glandulosa), we isolated a FDH cDNA (PagFDH1) and examined its expressional characteristics. The PagFDH1 is 1,499 base pairs long and encodes a putative 388 amino acid protein with an expected molecular mass of 42.5 kDa. The PagFDH1 protein has N-terminal mitochondria signal peptide and $NAD^+$ binding domain. Southern blot analysis indicated that a single copy of the PagFDH1 is present in the poplar genome. PagFDH1 is expressed highly in the suspension cells (especially in the lag and early exponential phases) and moderately in roots, flowers and leaves. ABA-mediated enhanced expression of PagFDH1 in response to drought and salt stress treatments indicates that the gene product could play an important role in the development of stress resistant trees.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.113-119
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• 1987

A study was conducted to determine the kiln drying schedule for hydrid aspen, This kiln drying schedule was found by oven drying method and developed by pilot testing of 2.0cm, 2.5cm, 3.0cm-thick green lumber. The results of this study were as follows: 1. Kiln drying schedule developed by oven-drying method was $T_{12}-E_5$ for 2.5cm-thick green lumber. 2. Drying times for 2.0cm-thick green lumber(127.0 percent moisture content) to 7.3 percent moisture content, for 2.5cm-thick green lumber(95.0 percent moisture content) to 9.7 percent moisture content, and for 3.0cm-thick green lumber(118.5 percent moisture content) to 10.0 percent moisture content were 45 hours, 45 hours, and 54 hours, respectively. 3. Drying rate from 90 to 10 percent moisture content of 2.5cm-thick lumber was about 0.7 times faster than that of 2.0cm-thick lumber and about 1.1 times faster than that of 3.0em-thick lumber. 4. End checks for 2.0cm-, 2.5cm-, and 3.0cm-thick green lumber occurred 95, 74 and 100 percent moisture content, respectively and reached maximum amount in 53, 41, and 60 percent moisture content, respectively. 5. No surface check and no honeycomb occurred. 6. Cupping and collapse slightly occurred and the quality of dry lumber was first.

• Journal of the Korean Wood Science and Technology
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• v.13 no.2
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• pp.14-34
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• 1985

One of the techniques for altering the properties of wood that has received considerable attention in the last twenty years is the formation of a wood-polymer composite (WPC) by irradiation and heat-catalyst polymerization of a monomer incorporated into the wood matrix. Wood-polymer composites are the new products having the superior mechanical and physical properties and the combinated characteristics of wood and plastic. The purpose of this experiment was to obtain the basic data for the improvement of wooden materials by manufacturing WPC and Staypak. The species examined was Hyunsasi-Namoo (Populus alba ${\times}$ P. glandulosa) which had not been utilized yet. Methylmethacrylate (MMA) as monomer, benzoyl peroxide (BPO) as initiator and methyl alcohol as bulking agent were used. The monomer containing BPO was impregnated into wood pieces by the dipping and the vacuum process for 2 hours. After impregnation, the treated samples were polymerized on the hot press with pressure and heat-catalyst methods. The results obtained were summarized as follows 1. The monomer loading into wood by the dipping process was 12.13 percent and 29.99 percent by the vacuum. The polymer loading into wood by the dipping process was 6.79 percent and 15.44 percent by the vacuum. 2. Comparing with Staypak, antishrink efficiency (ASE) of WPC was 12.5 to 13.6 percent on the radial direction and 14.70 to 18.63 percent on the tangential. Antiswelling efficiency (AE) was 14.40 to 17.22 percent on the radial direction and 17.18 to 42.1 8 to 42.14 percent on the tangential. Reduction in water absorptivity (RWA) was 8.19 to 15.5 percent. As a whole, the vacuum process was better than the dipping. 3. The specific gravity of control, Staypak and WPC were 0.44, 0.66 and 0.61 to 0.62, respectively. 4. In the bending strength test, the strength in case that the load direction is on the radial surface was greater than that which the load direction is on the tangential. 5. Increasing rate of stress at proportional limit in compression perpendicular to grain was 72.26 percent in case of WPC by the dipping process, 78.93 percent by the vacuum and 99.09 percent in case of Staypak.

• BMB Reports
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• v.42 no.7
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• pp.439-443
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• 2009

Dehydrins are group II, late embryogenesis abundant proteins that act putatively as chaperones in stressed plants. To elucidate the function of dehydrins in poplar, we isolated the $SK_2$-type dehydrin gene Podhn from Populus alba $\times$ P. tremula var. glandulosa suspension cells and analyzed its expression following treatments of abiotic stress, wounding and plant growth regulator. Sequence homology and phylogenetic analyses indicate Podhn encodes an acidic dehydrin (pI 5.14, 277 amino acids, predicted size 25.6 kDa) containing two lysine-rich "K-segments" and a 7-serine residue "S-segment", both characteristic of $SK_2$-type dehydrins. Southern blots show Podhn genes form a small gene family in poplar. Podhn was expressed in all tissues examined under unstressed conditions, but most strongly in cell suspensions (especially in the stationary phase). Drought, salt, cold and exogenous abscisic acid (ABA) treatments enhanced Podhn expression, while wounding and jasmonic acid caused its reduction. Therefore, Podhn might be involved in ABA or stress response.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.525-528
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• 2006

아임계 및 초임계수에 의한 목질바이오매스의 당화특성을 분석하기 위하여 분해공정 동안 압력을 23MPa(물의 임계압력)로 고정하고 물의 아임계 온도$(325^{\circ}C,\;350^{\circ}C)$와 초임계 온도$(380^{\circ}C,\;400^{\circ}C,\;425^{\circ}C)$에서 현사시나무 목분을 각각 60초 동안 처리하였다. 생성된 현사시나무의 분해산물에는 액상과 고형분의 분해산물이 섞여 있었다. 각 처리조건에 따른 목질바이오매스의 분해율은 온도가 상승함에 따라 증가하였으며 초임계 온도인 $425^{\circ}C$에서 최고 83.1%의 분해율을 나타냈다. 아임계 및 초임계수에 의해서 생성된 단당류는 고성능 음이온 교환 크로바토그래프(HPAEC)를 이용하여 분석하였다. 목질바이오매스의 초임계수 분해과정에서 처리 온도가 높아지면서 단당류 수율은 증가하는 경향을 보였으며, $425^{\circ}C$에서 가장 높은 7.3%의 단당류 수율을 나타내었다. 아임계 온도 범위에서는 현사시나무의 섬유소 성분 중에서 자일란이 우선적으로 분해되어 자일로스의 생성비율이 비교적 높았으며, 처리온도가 높아지면서 셀롤로오스의 분해에 의한 글루코오스 생성율이 급격히 상승하였다. 이렇게 생성된 단당류 성분들은 고온의 반응조건하에서 열분해 반응에 의해서 더욱 분해되어 퓨란계 화합물로 변형되었다.