• Korean Journal of Plant Tissue Culture
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• v.28 no.4
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• pp.189-195
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• 2001

This study was carried out to investigate the effects of in vitro culture condition and among lines on growth pattern of lateral buds from nodal cuttings of Phalaenopsis flower stalks. The ratio of bud growing into shoot from nodal cuttings of flower stalks were 90.9% and 54.4% on MS and hyponex medium, respectively. The number of buds grown vegetatively were increased remarkably on the MS medium containing 5 mg/L BA. The rate of buds grown vegetatively was higher in basal and middle parts than in upper part of flower stalks. The flower stalk sections cultured at 25~28$^{\circ}C$ showed the highest ratio of vegetative growth. Medium contamination was decreased by pretreatment of etiolation to the flower stalk. However, the pretreatment did not show specific effects on shoot development and reduction of phenolic compound. Average shoot number which was formed from flower stalk segments in 27 of 30 accessions were 3.17, while high number of shoots were obtained from Phal. 3020 and Phal. 3039. The growth pattern of lateral buds in F$_1$hybrids was similar to that of their parents.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.79-90
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• 2006

Tamarix chinenis blooms twice a you and its flowers, branches and leaves make the adjustment of tree shape. Propagation methods and growth characteristics of T. chinensis were studied in order to ascertain its potential use as one of vegetation resources for coast forestation and landscaping. The study results indicated that 1 or 2 you old hard wood cuttings showed higher rooting ratio than greenwood or semi hard wood cuttings. One to one mixture between vermiculite and pearlite appeared to be the best for bed soil, and sea sand and silt(loess) mixture was the next. Sea sand and granitic soil followed after. In terms of seasonal differences, spring cuttings showed the best rooting ratio, root number, and root length. Fall cuttings followed after spring cutting, and summer cuttings showed worst results regarding rooting ratio, root number, and root length. The best rooting promotion effects of growth regulators were observed with sea sand bed soils. There was no significant difference among growth regulators in terms of rooting and shoot growth. Low concentration below 100 ppm of growth regulators was enough for rooting promotion effect. In general, the number and mean length of roots and shoots were showed the excellent records in the sites with high rooting ratio. The study result strongly showed that T. chinensis can be considered as a suitable tree for coast forestation and landscaping because of its easy cutting propagation and rapid growth on saline lands.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.175-179
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• 2005

To develop a high efficiency plant regeneration system from in vitro cultures of strawberry, cv. Yeobong, petiole and leaf explants were cultured on MS basal medium containing a combination of 0.5 mg/L IBA and 3.2 mg/L kinetin or zeatin or benzyl amino purine (BAP) for 6 weeks, and leaf explants with dark pretreatment for a week ($T_1$), 2 weeks ($T_2$), and 4 weeks ($T_3$) were cultured on medium supplemented with 0.5 mg/L IBA and 3.2 mg/L zeatin under 16 hr photoperiod for 6 weeks. Shoot organogenesis was observed from the greenish calli containing minimal anthocyanin formed at proximal cutting edges of the leaf explant (57%) when cultured adaxial side on the medium, whereas was directly formed from a cutting edges of petiole explant (6.3%). Frequency of callus formation and shoot organogenesis at large size of leaf explant ($1.0{\sim}1.5\;cm^2$) was higher than small size ($0.5{\sim}1.0\;cm^2$), and dark pretreatment significantly improved the frequency of leaf explants that produced calli and shoots. The maximum frequency (87%) for shoot organogenesis was obtained from the leaf explants that transferred to a 16 hr photoperiod condition after the initial 4 weeks dark period. The improved frequency (87%) in comparision with control without dark pretreatment (27%). When the shoots were transferred to 1/2 MS basal medium, formed roots with 20 d of culture. The rooted plants were subsequently transferred to the pots and to the field.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.89-96
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• 2001

Carbohydrate and soluble protein reserves and regrowth characteristics in response to cutting height were investigated over four regrowth cycles of turf-type perennial ryegrass(Lolium perenne L. cv. preludeII). When the plants were at the full-vegetative stage (twelve weeks-old), three sequential defoliations at 3, 6 and 9 cm above the root base were imposed at 2-week intervals. Shoot dry weight in all three treatments continuously decreased with progressing regrowth cycle and the decreasing rate was higher as cutting height was lowered. TNC (total non-structural carbohydrate) in stubble at the end of the fourth regrowth cycle in 3, 6 and 9 cm cutting height decreased by 98%, 82% and 27%, respectively, comparing the initial content. TNC in roots also largely decreased with similar pattern in response to cutting height, whereas the absolute amount was much less compared to stubble. Soluble protein in stubble in 3, 6 and 9 cm cutting height decreased by 98%, 82% and 57%, respectively, at the end of fourth regrowth. A significant correlations between TNC (r=0.906) or protein (r=0.879) at the fourth defoliation and dry weight of regrowing shoots at the end of fourth regrowth were observed. these results indicated that cutting height closely influences the levels of organic reserves available for new growth, and that the levels of reserves might provide a useful tool as a determinant for regrowth dynamics.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.87-96
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• 2018

BACKGROUND: The vigorous shoot growth in upper part of apple tree canopy leads to poor fruit quality and flower bud formation in lower part of canopy. So, this study was conducted to develop the proper control method about the shoot growth in upper part of apple tree canopy. METHODS AND RESULTS: Trunks of 'Fuji'/M9 apple trees were cut (back pruned) to 2.5 m in tree height on 11 February (dormant) or 12 April (full bloom). Naphthalene acetic acid (NAA) was applied at 2.0% to cut surface when trunk was pruned. Prohexadione-calcium (Pro-Ca) was sprayed at 250 mg/L above 2.0 m in tree height at 23 April (petal fall). The NAA or Pro-Ca application after trunk was pruned at dormant (TR-2 and TR-3) significantly reduced shoot growth in upper part of canopy compared with the control (tree was only pruned at dormant, TR-1), but the percent of shoots showing the secondary growth of TR-3 was higher over 2 times than that of TR-2. The reduction of shoot growth in upper part of canopy by TR-2 and TR-3 increased the fruit red color from the lower part in the treating year and blooming of the lower part in the following year. CONCLUSION: Applying 2.0% NAA to cut surface of pruned apple trunk at dormant was the most effective way for stabilization of the tree vigor in upper part of the canopy in a high density apple orchard.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.193-197
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• 1982

1t is well known that the stem is filed with shoot units in the rice plant and each internode bears several crown roots. But it has not yet been ascertained that what controls the differential elongation of the crown roots in the same internode. Thereupon, author had been carried out this experiment to ascertain what controls the elongation of the crown roots in the same internode, especially on the conception of sink-source by leaf-cutting method. Generally, one shoot unit has two important sinks: one axillary bud (tiller) and several crown roots. When we removed the axillary bud, namely shoot unit has one sink: several crown roots, the crown roots formed near the midvein (source) were longer than the crown roots born near the axillary bud. And when the shoot unit has two sinks: one axillary bud and several crown roots, the other way, the crown roots formed at the prophyll unit of the tiller were longest, and the crown roots formed near the midvein were shortest and the crown roots born the near the tiller showed interim length. Juding from the present results, we can suppose that, when shoot unit has two sinks, axillary bud is superior sink than the crown roots. So that axillary bud grows faster than crown roots and tiller becomes a new source. Therefore the crown roots which formed at the new source and the crown roots born the near the new source are longer than others.

• Journal of Ecology and Environment
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• v.41 no.3
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• pp.66-71
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• 2017

Background: The sprouts of oak species play an important role in maintaining the oak community in a disturbed environment. In this study, we cut 1-year-old oak in three times during the 3 years and measured the sprout responses to know sprouting ability of six deciduous oaks in Korea. Results: Oak sprouts have appeared in spring and fall, and some of the sprouts had lifespan as short as a month. As the number of cutting increases, sprout number of Quercus acutissima increased whereas the other oak species decreased or died. The average number of sprouts over the 3 years was from 1.4 (Quercus mongolica) to 2.2 (Q. acutissima) per individual. Quercus serrata died after the second cutting, and Quercus dentata died after the third cutting. So, the two species have the lowest sprouting ability among six oak species. The sprouts grew actively during fall and slowly in summer. The sprout length during the 3 years was in the following descending order: Q. acutissima, Quercus aliena, Q. dentata, and Q. mongolica. Sprout of Q. acutissima and Q. aliena generated steadily over the 3 years, and sprout of Quercus variabilis and Q. mongolica was changed by year. After the 3 years, the number of sprouts increased only in Q. acutissima but sprout number of the other five oak species decreased. The sprout length of Q. acutissima, Q. aliena, and Q. variabilis increased, but sprout length of the other three oak species decreased. The average survival rate of saplings over the 3 years was in the following descending order: Q. acutissima, Q. aliena, Q. variabilis, and Q. mongolica. Conclusions: As a result, the sprouting ability of Q. acutissima was the highest. Such level of sprouting ability may be the evidence of how Q. acutissima community exists as a dominant species in a disturbed environment in lowlands of Korea peninsula.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.63-67
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• 1991

Various concentrations of ${\alpha}$-naphthalence acetic acid(NAA) as a root-promoting substance were tested in hardwood cutting of the mulberry(Morus bombycis Koidz., cultivar : Shinkwangppong) to make clear the callusing effect on the budding and root growth. Budding and shoot growth of cuttings were delayed at high concentrations of NAA within 10 days of callusing. Especially more severe is it at higher than 50ppm. More than 93% of them, however, budded in two weeks when callused at less than 100ppm NAA. Although rooting was accelerated at high concentration of NAA from the bigining of cutting, after that, rooting percentage increased to reach 100% in 35 days of cutting in any concentration except 150ppm with relatively low rooting. Root growth was utmostly accelerated at 50ppm NAA to show the highest amount in number, length and weight of roots per cutting although high concentration of it decreased mean root length.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.1-10
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• 1987

This study was carried out to examine the influence of shading and root-cutting on the survival and growth of Pinus koraiensis seedlings. 1, The highest survival percentage of seedlings transplanted to transplanting bed appeared at the plot of 19% in shading. The 50% of the seedlings were survived if half of them were root-cutting. 2. Shoot elongation, root growth and diameter increment were the best at the plot of 100% in relative light intensity. However, those were the best at the plot with 1/4 root cutting. 3. The increase of needle fascicle number and the growth of needle surface area per seedling were the longest at the plot of 63% relative light intensity. Among root cutting treatments the 1/4 cutting plot showed the largest growth of needle areas.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.228-234
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• 2015

Using either the apical or axillary bud of the endangered species Abeliophyllum distichum Nakai, we tested the effect of bud position and culture method on shoot proliferation and rooting. In shoot proliferation, the axillary bud explant was more effective than the apical bud and the effect was fostered by BA treatment, whereas no differences were observed in shoot elongation by the explant position. Spontaneous rooting was observed in the MS basal medium and resulted in conspicuous differences in the explant position : more than 80% in apical bud explant and 28% in axillary bud explant was achieved, respectively. The positional effects were also observed in BA pre-treatments: generally vertical culture method appeared to be better in shoot proliferation, growth, and rooting than that of the horizontal culture method regardless of the BA pre-treatment duration. The highest shoot multiplication was achieved through the vertical culture method with axillary bud explant, whereas the best shoot elongation and rooting was obtained using the vertical culture method with the apical bud explant. Apical bud explant was superior to axillary bud explant in ex vitro micro-cuttings and revealed a significant difference in shoot growth and root development. The above results suggest that explant position and culture method influence the efficiency of micropropagation for a rare and endangered plant Abeliophyllum distichum.