• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.322-329
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• 1990

A group of Pinus densiflora trees attacked by Rhizina root rot were observed at Kangnung. Diseased roots are characterized by rot patches, radial rot traces or formation of adhesive soil masses. The damage has proceeded about 6m per annum, and the pathogen in the infected soil was detected by trap logs. Ascospores of Rhizina undulata was germinated by heat shock at $37^{\circ}C$ for 24 hours or at $40^{\circ}C$ for 17 hours. The mycerial growth was optimum on PDA medium at $25-30^{\circ}C$and pH 5.6-6.3. Coniferous trees were more susceptible than non-coniferous trees in inoculation test in vitro.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.107-113
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• 2002

This study was performed to obtain the information on fruit set, propagation and flowering habits of the exotic ornamental bottle brush tree (Callistemon citrinus). Trees have fruit capsules for four years since the fruit set and they have enlarged for three years. While 2 and 3-year-old capsules have similar seeds in number and size, 1-year-old ones have fewer and smaller seeds. Most dried capsules open when they have 75％ relative water contents. Two year old seeds which they were dried at 30％ germinated better than others. Removal of capsule bearing twigs resulted in greatly increased subsequent flower numbers (an average of 14 flowers per tree) compared with twigs where seed capsule were allowed to remain. In cutting for propagation, semi-hard wood branches dipped in 100mgι$^{-1}$ IBA for 24 hours rooted at 86.4 ％ and had an average of 12.6 primary roots.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.323-330
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• 2021

Zygotic embryo culture was performed to propagate evergreen oak, Quercus myrsinifolia, which has recalcitrant seeds and is difficult to propagate by cuttings. Zygotic embryos appeared in WPM medium after 14 days, and after 56 days, they developed into complete plants with cotyledons and roots. The medium suitable for zygotic embryo culture was 1/4 WPM medium, showing a shoot growth of 2.43 cm and root growth of 8.7 cm after 8 weeks of culture. As a result of investigating the effect of GA₃ on the growth of plants germinated from zygotic embryos through GA₃ treatment, the best growth was shown in 0.5 mg/l GA₃ treatment. The in vitro rooting and growth of IBA-treated zygotic embryo-derived plants were good in the 0.5 mg/l IBA treatment and rooting and shoot growth were not observed at higher concentrations. And the callus induction rate also increased as the concentration of IBA increased. Plants grown in vitro were transferred to a plastic pot containing artificial soil and acclimatized in a greenhouse for about 4 weeks, resulting in more than 90% survival. As a result of this study, the zygotic embryo culture method was confirmed to be effective for mass propagation of Q. myrsinifolia. The results of this study are expected to contribute significantly to the mass propagation of elite Q. myrsinifolia.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.136-142
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• 2016

Lespedeza species are mainly used for wildlife food and cover and for erosion control. The germination of these species can be enhanced after a fire occurrence in forest, which is known as fire-activated seeds to germinate. While the heat treatment could break seed dormancy of Lespedeza, its germination rate was quite low. We investigated that chemical scarification could promote germination of L. tomentosa. Seeds were soaked in 100% sulfuric acid (H₂SO₄) for 0, 1, 3, 6, 12, 24, 48, 96, 192, and 384 min, and then washed in distilled water for 24 h. Very few seeds were germinated in control (H₂SO₄ for 0 min). More than 90% of seeds were germinated in H₂SO₄ for 24, 48, and 92 min. However, some damage was observed in roots and cotyledons of seedling dipped in H₂SO₄ for a long time. To search the optimal soaking time in H₂SO₄ without defects, seeds scarified in H₂SO₄ for 30, 60, 90, 120, 150, 180, and 300 min were sown the commercial soil medium. Seeds treated with H₂SO₄ for 90 min and 150 min emerged by about 92% and 84%, respectively. Therefore, H₂SO₄ treatment could break the seed dormancy of Lespedeza species, and especially in case of L. tomentosa the optimal treatment time in sulfuric acid was one to two hours. Germination of L. tomentosa began promptly following the scarification and was completed within about one month, indicating that seeds has no physiological dormancy, just has physical dormancy.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.352-358
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• 2013

For the germination and differentiation of immature embryos obtained by artificial crossing between tetraploid grape 'Fujiminori' (Vitis vinifera ${\times}$ V. labruscana) and triploid 'Summer Black' (V. labruscana ${\times}$ V. vinifera), were incubated in vitro using MS medium supplemented with $GA_3$ or coconut water (CW) at various concentrations. The percentage of embryo formation of 'Fujiminori' ${\times}$ 'Summer Black' was 64.3%. Embryo germination percentage was higher than 95% in all the $GA_3$ treatments at the concentrations of 0.01, 0.05, 0.25, and $1.25mg{\cdot}L^{-1}$. However, only 15.8-31.6% of the germinated embryos successfully developed into normal plantlets. At higher concentration of $GA_3$, the plantlets developed infirm hypocotyls with over elongated and less enlarged structure. Among the treatments of CW at the concentrations of 5, 10, 15, and 20% (v/v), 10% and 15% were more effective and plantlet achievement percentage were 68.4 and 66.7%, respectively. The addition of 10% CW was most effective to obtain plantlets with optimal shoot length, node and root numbers. 15% CW was suitable to obtain plantlets with longer roots. Accordingly, the embryo culture using the MS medium supplemented with 10-15% CW was observed to be more efficient for germinating and growing the immature embryos produced from artificial crossing between tetraploid grape 'Fujiminori' and triploid 'Summer Black'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.232-237
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• 2003

Benzyladenopuyine (BA) commonly used for soybean sprout production is of high price. The study was carried out to determine the effect of BA treatment time during seed imbibition on growth and development of soybean sprouts and to analyse its treatment cost. The soybean seeds of 4 cultivars were soaked in 4 ppm BA solution during the first 5.5 hour imbibition (EFHI), the second 5.5 hour imbibition (SFHI) immediately after 0.5 hour aeration, or whole 11.0 hour imbibition (WFHI) intervened by aeration. On the 6th day after culture, the soybean sprouts were classified into 4 categories on the base of hypocotyl length; ＞ 7cm, 4 to 7cm, ＜ 4 cm and not germinated, and their morphological characters, fresh and dry weights were measured. Water absorption of the seeds was sharply reduced after it was almost done for the first 5.5 hours. The percentage of sprouts with hypocotyls of longer than 4cm was higher in FFHI treatment than in the other two ones. Regardless of BA imbibition time and periods, the lateral roots were not observed. WFHI treatment showed shorter hypocotyl and root lengths but thicker hypocotyl and hook diameters than FFHI and SFHI treatments. All component fresh and dry weights except cotyledon fresh weight were nearly same. Treatment cost of BA was the lowest in SFHI treatment. It is concluded that BA treatment during SFHI is the best time because its treatment time did not affect sprout growth but its treatment cost.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.100-106
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• 1995

This study was conducted to find the factors affecting somatic embryogenesis in suspension culture of Rehmania glutinosa and investigate the possibility of artificial seed production by encapsulation of somatic embryos. Linsmeier-Skoog medium was appeared as proper for somatic embryogenesis. Sucrose with $3{\sim}5%$ as carbon sources was good for somatic embryogenesis, and both ammonium and nitrate nitrogen were necesary for normal somatic embryo production. BA with NAA or kinetin with NAA were better than the use of cytokinin alone for both somatic embryogenesis and numbers of somatic embryos. $AgNO_3$ as protectant for vitrification of seedlings in vitro culture had no harmful effect on somatic embryos. Sphericity of encapsulated seeds was good at 3% gel of sodium alginate but germination was better at 2.5% sodium alginate level. Artificial seeds were germinated and developed normal shoots and roots under in vitro condition.

• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.531-539
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• 1994

We examined the in vitro rooting and survival of tissue cultured plantlets of Quercus acutissima Carr. and Pinus densiflora Sieb. et Zucc. after addition of Pisolithus tinctorius(Pt) ectomycorrhizal fungus inoculum to the medium and effects of three levels of sucrose and phosphorus in culture media. Shoots of Quercus acutissima were obtained from winter buds of a 30-year old tree and cuttings of Pinus densiflora from germinated seed, and they were inoculated with Pt in vitro. In both species, Pt enhanced shoot length, survival, number of adventitious roots, root length, and rooting percentage. Survival in Quercus acutissima was increased from 75% in control to 100% in Pt inoculation. Pt inoculation increased the percentage of rooting from 20% to 70% in Quercus acutissima cuttings and from 63% to 100% in Pinus densiflora cuttings. It is concluded that mycorrhizal inoculation to tissue cultured Quercus acutissima Carr. and to in vitro cutting of Pinus densiflora Sieb. et Zucc. has practical application to improvement of poor root development and initial period of reduced shoot growth in vitro.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.634-639
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• 2006

In order to develop a disease-resistant root stock for the growth of watermelon, an efficient regeneration system of the gourd(Lagenaria leucantha Duch.) inbred line GO701-2 via organogenesis was established in this experiment. Using proximal parts of cotyledon explant excised from germinated seedling in vitro, maximum adventitious shoot formation (39%) was achieved on MS medium where cytokinin (BA) and auxin (IAA) were added at a concentration of 3mg/L and 0.1mg/L, respectively. Roots of the elongated shoots were successfully formed on MS medium without adding any plant growth regulators. The cucumber CsGolS1 gene known as a resistance gene against biotic and abiotic stresses, was constructed into the binary vector pBI121 under the control of CaMV 35S promoter. When the gene was introduced into the genome of gourd by Agrobacterium-mediated transformation, putative transgenic plants were obtained with the transformation efficiency of approximately 20 percent.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.600-607
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• 2001

This study was conducted to estimate the capability of Populus alba ${\times}$ glandulosa and Betula schmidtii for the uptake of Pb from the lead-contaminated soil and their tolerance to lead. Rooted cuttings in the former species and germinated seedlings in the latter species were planted in pots and irrigated with Pb-containing water for 60 days. In both tree species, growth inhibition was observed in 800, and 1,500ppm of $Pb(NO_3)_2$. Most Pb was accumulated in plant roots and only a small portion was transported to the shoots. The translocation rates of Pb for B. schmidtii and P. alba ${\times}$ glandulosa were 1.6-2.6% and 1.2-1.6%, respectively. The maximum Pb content accumulated in shoots was 468.0mg/kg d.w. in P. alba ${\times}$ glandulosa, and 602.0mg/kg d.w. in B. schmidtii. Although tolerance to lead was generally higher in B. schmidtii than P. alba ${\times}$ glandulosa, the highest tolerance to lead was observed in P. alba ${\times}$ glandulosa clone, 72-16. Finally, we discussed the applicability of P. alba ${\times}$ glandulosa and B. schmidtii for phytoextraction based on their Pb uptake ability, high biomass production, and easiness in large-scale cultivation.