• Journal of Korean Society of Forest Science
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• v.57 no.1
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• pp.26-31
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• 1982

The hybrid poplar, populus alba ${\times}$ P.glandulosa $F_1$ shows a strong ability to produce root suckers. The relationship between crown density and root sucker was studied and the other factors that may be related to production of root sucker were also discussed. The possibility was also discussed to use its root suckers for fuelwood forests and vegetation in the area that erosion control is needed.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.90-98
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• 1985

Inheritance of four isozymes, GOT, ACP, MDH and ADH, in Populus alba ${\times}$ P. glandulosa was investigated with starch gel electrophoresis. All four isozymes showed bands. For GOT, six or seven loci were postulated and observed segregation of hybrids at five variable loci was in agreement with expected segregation. Two loci were postulated in ACP; one locus showed no variation but the other locus showed variation. As one additional band was found in P. alba ${\times}$ P. alba (italy), hybrids from P. alba ${\times}$ P. alba ${\times}$ P. glandulosa showed more variation than hybrids from P. alba ${\times}$ P. glandulosa. One monomorphic locus and two variable loci were postulated in MDH. For ADH, both parents were turned out as homozygotes but for different alleles and thus all progenies were heterozygotes. ADH in hybrids seems to be a dieter enzyme as it showed on additional band between two parental bands. There were no variation in band betweens of four enzymes among the clones of P alba and P. glandulosa, respectively.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.1-5
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• 1979

The arrangement and the number of vascular bundle in petiole were investigated with the hybrid Populus alba${\times}$P. glandulosa and both parents. 1. The variation in number and the arrangement of the vascular bundle in petiole were smaller at middle point than at nearer point to the leaf blade. 2. A small variation was found in the arrangement of the vascular bundle within a tree, same clone and same species. 3. Five shapes of vascular bundle were recognized in the $F_1$ hybrid, 26.7 per cent of the $F_1$ hybrid has the same shape with P. alba, 13.3 percent with P. glandulosa and 53.3 per cent of the $F_1$ hybrid shows the $F_1$ shape caused by hybridization. 4. The hybrid clones which show the same shape with P. alba are 66-20-1, 66-6-8, 65-22-11 and 64-6-44, hybrid clones of 65-95, 66-14-93 have the same shape with P. glandulosa. Hybrid clones of 66-15-3, 67-6-3, 65-22-4, 66-26-55, 68-1-54, 66-14-99, 65-29-19, 66-25-5 have $F_1$ shape.

• Journal of Korean Society of Forest Science
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• v.64 no.1
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• pp.1-10
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• 1984

Two fast-growing clones 65-29-19 and 66-6-8 and two less fast-growing clones 66-14-29 and 66-14-99 were compared at intensively cultured plots to identify what morphological characters are related to fast growth and high biomass yield of Populus alba ${\times}$ Populus glandulosa $F_1$. The plantations were established in the spring of 1982 and 1983 at the Seoul National University nursery in Suweon. Differences in dry matter production were found among two-year-old clones but not, among one-year-old clones. Highly significant correlations were found between total leaf area per tree and total dry weight per tree and between total branch length per tree and total dry weight per tree for two-year-old clones. This relation was more obvious during the late growing season. Morphological characters desirable for producing high biomass identified in fast-growing clones were as follows; high shoot-root ratio, high leaf surface area per tree, long leaf retention period, and many small leaves and compact crown architecture in the upper portion of true crown.

• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.15-30
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• 1983

To select the superior clones of Populus alba ${\times}$ Populus glandulosa $F_1$, growth and some growth-related physiological characters were examined for thirteen, one-year-old and fifteen, two-year-old clones, respectively at the Seoul National University nursery in Suweon, Clonal differences in growth (total dry weight per tree), leaf area per tree and leaf chlorophyll content per tree at tow-year-old plots were highly significant at the 1% level, but not at one-year-old plots, Highly significant correlation was found between leaf area per tree and total dry weigh per tree (r=0.865), between leaf chlorophyll content per tree and total dry weight per tree (r=0.888), and between photosynthetic ability per tree and total dry weight per tree (r=0.745). The photosynthetic ability and leaf chlorophyll content per unit leaf area of one-year-old plant increased with increasing leaf order number from top. reached maximum value in the twenty-eithth and thirty-third leaves, respectively, and then decreased gradually from those leaved to base, Clones 68-1-54, 66-26-55 and 65-22-11 showed test growth based on leaf area per tree, leaf chlorophyll content per unit leaf area and photosynthetic ability of leaf tissue per unit area. Growth yield of populus alba ${\times}$ P. glandulosa $F_1$ clones could be estimated from either leaf area per tree of leaf chlorophyll content per tree. Therefore, measurements of leaf area and leaf chlorophyll content appear useful to select superior populus clones early growth.

• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.63-71
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• 1985

To sled the superior clones of Populus alba ${\times}$ Populus glandulosa $F_1$, growth and some growth-related enzyme activities were examined for thirteen, two-year-old and fifteen, three-year-old trees at Seoul National University nursery in Suwon. Clonal differences in total dry weight per tree and leaf surface area per tree were significant at the 5% level. Significant correlations were found between total dry weight per tree and leaf surface area per tree (r=0.875), between leaf peroxidase activity per tree and total dry weight per tree (r=0.854), and between leaf nitrate reductase activity per tree arid total dry weight per tree (r=0.914). Leaf peroxidase and nitrate reductase activities per unit fresh weight of one-year-old tree increased with increasing leaf order numbers basipetally, reaching maximum values in the eighteenth and thirty-third leaves, respectively, and decreased gradually from those leaves to basipetal lower leaves. Clones 65-29-19, 66-15-3, 65-22-11, 66-14-93, and 66-26-55 among two-year-old trees, and clones 64-6-44, 66-14-29, 66-26-55, 65-22-11, and 68-1-54 among three-year-old trees showed greater leaf surface areas, peroxidase and nitrate reductase activities per unit leaf fresh weight than other clones, Growth of Populus alba ${\times}$ Populus glandulosa $F_1$ clones might be estimated from either leaf surface area per tree or peroxidase and nitrate reductase activities per tree. Therefore, measurements of leaf surface area and leaf enzyme activities appear useful to select superior Populus clones at early growth stages.

• Journal of the Korean Wood Science and Technology
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• v.30 no.1
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• pp.63-71
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• 2002

The bark of P. alba × glandulosa, P. euramericana and P. nigra × maximounczii F₁, several Populus trees, were collected, extracted with acetone-H₂O(7:3, v/v), fractionated with hexane, chloroform and ethylacetate, and freeze dried to give some dark brown powder. Each fraction of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents and then identified by thin layer chromatography using TBA and 6% acetic acid as developing solvents. The structures of the isolated compounds were characterized by ¹H, ¹³C and 2D-NMR tools including mass spectrometry. Most of the compounds were flavonoids and salicin derivatives as follows: (+)-catechin, taxifolin, aromadendrin, eriodictyol, naringenin, sakuranetin, sakuranetin-5-O-𝛽-D-glucopyranoside, neosaturanin, salireposide, p-coumaric acid, and aesculin from P. alba × glandulosa, (+)-catechin, salireposide, populoside and salicortin from P. euramericana and (+)-catechin, quercetin, padmatin, salireposide, populoside and salicortin from P. nigra × maximounczii F₁.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.19-26
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• 1978

In order to investigate the difference of rootability between 15 clones of Populus alba${\times}$glandulosa selected based on the growth performance, rooting of cutting experiments with these 15 clones were conducted at the nursery for six years from 1970 to 1975. Cutting experiments in a temperature controlled incubator in which the temperature of the cutting bed were set to $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ were also performed. Along with these experiments air layering experiments were performed to compare with the rootabilities obtained from nursery trial. The results obtained so far could be summarized as follows. 1. The best rooting clones were 65-22-4 and 65-22-11, and the average rooting percentages of these two clones for six years were 76.7%, and 72.9% respectively. The poorest rooting clone was 66-6-8 showing average rooting percentage of 45.8%. 2. The middle class of rooting percentage was ocuppied by the clones; 66-14-29, 66-14-93, 66-25-5 and 67-6-3, and the range of their rooting percentage was 60~69% on average. 3. The rooting performances observed through the nursery, the incubator and the air layering experiments were almost the same with exception of few clones. 4. P. alba${\times}$glandulosa showed the best rooting percentage at the cutting bed of $20^{\circ}C$ 5. The most roots, i.e. 78.5% of root per cutting were developed from the bottom part of the cutting shoot. 6. Adventitious and call use roots could observe in the cuttings.

• 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 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.