• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.242-248
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• 2023

This study was conducted to evaluate the effects of trinexapac-ethyl (TE) and prohexadione-calcium (PC) on the growth and turf quality of perennial ryegrass (Lolium perenne L.). Treatments were designed as follows; control (non-treatment), TE (TE 0.01 a.i. g·m^-2·100mL^-1), and PC (PC 0.01 a.i. g·m^-2·100mL^-1). Compared with control, turf color index and chlorophyll content of TE and PC treatments were not significantly different. As applied plant growth regulators (PGRs), shoot length in the TE and PC was decreased by 8.9-12.4% and 6.7-13.6%, respectively, and clipping yield by 44.4-45.8% and 40.6-40.9%. When evaluated with the growth of shoot length after applying PGRs, residual days of TE and PC were 43.6 and 37.9 days after treatment of PGRs (DAT) in the 1st experiment (July 29-August 26), respectively, and 38.3 and 39.5 DATs in the 2nd experiment (September 30-October 28). These results indicated that an application of TE or PC decreased shoot length and clipping yield in the perennial ryegrass, and their residual time was about 40±3 DATs. Perennial ryegrass applied with PGRs like TE and PC was not significant seasonal difference, and might be not phytotoxic.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.80-80
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• 2018

Hosta is a genus of the family Asparagaceae and distributed in East Asia. There are six Hosta species (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) native to Korea and among them, four species (H. minor, H. jonesii, H. venusta and H. yingeri) are endemic to the Korea peninsula. Hosta is generally propagated by seed, crown division or tissue culture. However, tissue culture is a more efficient method to mass proliferation, a new cultivar development and disease-free plantlet production in a limit time. Hence, we conducted this study to evaluate the influence of various plant growth regulators (PGRs) treatments on the induction of callus and somatic embryo of the six Hosta species. Leaf, petiole and root were used to select optimum tissue culture explants. Petiole explants thus only were used for callus induction and somatic embryogenesis with TDZ (0.1, 0.5 or 1.0mg/L) and NAA (0.1 or 0.5 mg/L) combinations. After 12 weeks of culture, the highest rate of somatic embryogenesis was achieved on modificated MS medium containing 1.0 mg/L TDZ and 0.1 mg/L NAA in H. capitata and H. minor (15.5%, respectively), 0.1 or 0.5 mg/L TDZ and 0.1 mg/L NAA in H. jonesii (22.2%), 1.0 mg/L TDZ and 0.5 mg/L NAA in H. yingeri (26.7%), and 0.1 mg/L TDZ and 0.5 mg/L NAA in H. venusta (53.3%). H. clausa showed very low effect on somatic embryogenesis by PGRs; 2.2%. There was interspecies difference to PGRs respond for callus and somatic embryo induction. Regenerated multiple shoots and plantlet of H. minor, H. jonesii, H. venusta and H. yingeri were obtained via somatic embryogenesis.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.333-340
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• 2011

This study was conducted on the effect of plant growth retardants (PGRs) on growth of potted Ardisia pusilla and Ardisia pusilla var. variegata grown for a short term in an ebb and flow system. Plants were planted in 10 cm plastic pots, containing a mixture of peat moss and perlite (1 : 1, v/v) on 30 June 2005 and were grown until 23 Sep. 2005. The PGRs used were 50, 200, 350, 500 $mg{\cdot}L^{-1}$ daminozide (B- 9), 10, 40, 70, 100 $mg{\cdot}L^{-1}$ paclobutrazol (Boundy), and 5, 15, 25, 35 $mg{\cdot}L^{-1}$ ethephon (Florel). On every irrigation, the nutrient solution containing PGRs was supplied at a 2 cm depth and was kept for 15~20 minutes. The surplus nutrient solution was drained back into the tank for next irrigations. In both cultivars, paclobutrazol gave the most pronounced effect in inhibition of stretchiness. Ardisia pusilla, which was pinched just before initiation of paclobutrazol treatment, resulted in the greatest inhibition of shoot elongation. Daminozide treatments above 200 $mg{\cdot}L^{-1}$ also gave reduction of shoot length. However, ethephon treatments gave no dwarfing effect in Ardisia pusilla. Inhibition of stretchiness was observed even in the lowest concentration treatments. Among the PGRs, paclobutrazol was the most effective in suppressing plant stretchiness.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.60-60
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• 2020

To establish in vitro axillary bud culture conditions of Echinosophora koreensis Nakai, one of Korean endemic endangered species famous for beautiful flowers, we tested the influence of plant growth regulators (PGRs) in shooting and rooting stage from in vitro plants. In shoot multiplication, addition of 6-benzylaminopurine (BA) to the media induced 2.5 to 3 shoots per bud during 4 weeks of culture. And media including 0.5 mg L^-1 thidiazuron (TDZ) produced 3 to 4 shoots per bud. However, zeatin and isopentenyl adenine (2-ip) were not successful to increase shoot number, and the combination treatments of BA with other PGRs were also not effective. Shoots were smaller than 2 cm in length, in most of the treatments. In rooting, naphthalene acetic acid (NAA) treatments in the range of 0.5 to 4.0 mg L^-1 appeared to increase rooting rate by 10% to 60% approximately when compared with the control but roots developed with callus clusters. Indole butyric acid (IBA) addition had little effect on rooting (below 10%), while some roots were longer than in NAA treatments and some shoots were longer on high IBA concentrations (4.0 to 8.0 mg L^-1). It is suggested that micropropagation is a highly applicable and promising to multiplication and conservation of rare and endangered endemic species.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.213-221
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• 2022

Wild garlic (Allium victorialis var. platyphyllum, AVVP) is a nontimber forest product used as an edible and medicinal vegetable. AVVP is usually propagated form offspring bulbs but it takes a long time to harvest. Using tissue culture technology could overcome this problem. This study investigated the optimal conditions for shoot multiplication, root growth, and plant growth by scooping AVVP bulbs. AVVP bulbs harvested from Ulleung Island, Korea, the main producer of AVVP, were surface-sterilized and used for in vitro propagation. Shoot multiplication was performed by the scooping method. More than five multiple shoots were induced from scooped tissue in Quoirin and Lepoivre (QL) medium containing plant growth regulators (PGRs); the maximum number of multiple shoots were induced from scooped tissue in QL medium containing 0.45 μM thidiazuron (TDZ) after 16 weeks of culture. Roots were induced directly at the base of the shoots in all treatments. In vitro rooting depended on the type of PGRs, and the best root-inducing treatment was QL medium containing 9.84 μM indole-3-butyric acid (IBA). Plants with in vitro roots were transferred to pots containing artificial soil and successfully acclimatized for 4 weeks. The acclimatized plants showed a survival rate of 80% after 20 weeks and gradually promoted growth depending on the acclimatization period. The results of this study will be of great help to AVVP dissemination through sustainable mass propagation.

• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.524-529
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• 2006

In vitro culture system was established to induce multiple shoots of Albizzia julibrissin Duraz. by investigating the effects of cytokinins. Cotyledon, hypocotyl and root explants were cultured on MS media supplemented with either three different plant growth regulators or their combinations. The most effective cytokinin sources were zeatin 2.0 + TDZ 0.5 mg/L in cotyledon, zeatin 1.0 mg/L in hypocotyl, and BA 0.2 + TDZ 0.01 mg/L in root explant for producing shoots ($5.67\;{\pm}\;1.20$, $19.50\;{\pm}\;3.50$, and $20.50\;{\pm}\;2.47$, respectively). Also, zeatin treatment was tended to induce more shoots rather than the combinations of other cytokinins. In addition, the root induced in 1/2 MS medium without any plant growth regulators was longer and thicker than treatments of IBA, NAA, IAA and 2.4-D as auxins. Overall, the highest average percent of in vitro shoot formation was 73% from three different types of explants with treatment of zeatin (1.0mg/L).

• Korean Journal of Plant Resources
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• v.35 no.5
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• pp.667-674
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• 2022

This study was conducted to determine the three main factors [rooting time, plant growth regulators (PGRs), rooting medium] of cuttage for mass production of Sageretia thea. The experiment was observed on cuttage tray after 120 days and classified by rooting times, plant growth regulators, rooting medium. Materials were collected from natural habitats of S. thea from the Korean peninsula at March, July and September during 2019. As a result of the experiment, rooting times were showed statistically significant differences. March group's rooting rate and root length were 15 and 200% better than others. In PGRs experiment by concentration, There was no significant correlation between the control and experiment in terms of rooting rate. However, In the case of root length, IBA 500 mg/L, IBA 250 mg/L and IAA 1,000 mg/L groups were lengthened up to 170% compared to the control group, confirming statistically significant differences. As a result, we recommend treating cuttings with IBA 500 mg/L in March with Hardwood cutting.

• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.452-457
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• 2008

In order to develop an efficient micropropagation technique effect of plant growth regulators (PGRs) affecting on shoot proliferation from shoot apex in Pyrus ussuriensis was tested. Generally, there was no conspicuous effect on shoot induction by the treatment of PGRs and one or two shoots/explant were induced when cultured on MS medium supplemented with BA and/or BA plus NAA. Both apical shoot necrosis and hyperhydric shoots were observed frequently in multiplied shoots, and callus was formed at the basal part of shoots. About 20% spontaneous rooting was achieved in growing shoots, however the proliferated shoots exhibited poor rooting rate in gelrite supported media. When we tried to ex vitro rooting of the shoot cutting, the shoot cuttings rooted up to 50% with 100 mg/L IBA application. The rooted plantlets grew normally after acclimatization in the greenhouse.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.42-48
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• 2017

This study was conducted to establish the optimal condition for in vitro propagation of Disporum sessile. In the experiments with different kinds of media (MS, B5 and WPM) and explant types for shoot induction and elongation, the highest number of shoot inductions (2.5/explant) was shown when the axillary bud explants were cultured on MS medium without plant growth regulators (PGRs). The best shoot elongation (7.2 cm) was also obtained when the apical buds were cultured on MS medium. The effect of BA pulse treatments with in vitro shoots was also examined. The highest in shoot induction (2.29/explant) and elongation (7.28 cm) was observed when the shoots from axillary buds were cultured on the media without PGRs. However, it decreased with increasing duration of BA pulse-treatment. The highest rooting rate (100%) and number of root inductions (21.3/explant) were achieved with 1.0 mg/L indole-3-butyric acid (IBA) treatment, whereas no differences were observed by different shoot types. The regenerated in vitro plantlets were hardened and successfully established in soil.

• Korean Journal of Plant Resources
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• v.24 no.3
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• pp.280-285
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• 2011

In this study, we established a novel somatic embryogenesis and plant regeneration system through cell suspension culture of white dandelion (Taraxacum coreanum NAKAI.). Embryogenic calli could be initiated from leaf and root explants of sterile seedlings on solid Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) after 3-week cultures. To proliferate embryogenic calli rapidly, cell suspension culture was performed with transferred to liquid MS medium with various combinations of plant growth regulators (PGRs) including 2,4-D, ${\alpha}$-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), $N^6$-benzylamino purine (BAP), thidiazuron (TDZ), and kinetin. During suspension cultures, embryogenic calli not only greatly proliferated, but shoot organogenesis also simultaneously occurred from the surface of somatic embryos. Among them, TDZ at lower concentration, 0.1 mg/L produced the highest efficiency of somatic embryo formation and shoot organogenesis. Rooting of embryogenic calli with adventitious shoots was done on solid MS medium containing 0.1 mg/L NAA and 0.3% activated carbon. Nearly 80% of embryogenic calli with shoot organogenesis could be rooted normal. Well-rooted plantlets were transferred into pots under a greenhouse condition, and plants derived from this system appeared phenotypically normal.