• Korean Journal of Plant Tissue Culture
• /
• v.24 no.5
• /
• pp.291-294
• /
• 1997

The experiments were carried out to determine the optimum conditions for the direct embrogenesis from the cotyledon derived zygotic embryo culture of Paeonia lactiflora Pall. Different peony tissues derived from zygotic embryos were cultured on MS medium with and without 2,4-D. Somatic embryos were formed from the cotyledons cultured on the medium without 2,4-D. The somatic embryogenesis from cotyledons was promoted in the growth regulator-free MS medium containing 1.65~3.3 g/L $NH_4NO_3$ and 30~40 g/L sucrose. The maximum frequency (80.0%) of somatic embryo formation was obtained from the cotyledons excised from zygotic embryos that cultured on MS medium containing 3.3 g/L $NH_4NO_3$. Epicotyl and roots were elongated from a somatic embryo by adding 0.3 mg/L GA$_3$ in the medium or the cold treatment at 4$^{\circ}C$ more than three weeks at 4$^{\circ}C$.

• Korean Journal of Environment and Ecology
• /
• v.27 no.5
• /
• pp.529-543
• /
• 2013

In this study, Pteridophytes flora of Jirisan National Park were recorded 135 taxa, and they belong to 21 families, 39 genera, 123 species, 11 varieties and 1 forma. In the field, 38 taxa were not found on literature exists and 22 taxa were newly confirmed. The results obtained from this study were as follows: Deciduous (d), Evergreen (e) and Summer-deciduous (sd) were calculated as 50.0%, 46.3%, 2.2%, respectively and the Deciduous (d) has the highest value compared to the other leaf phenologies. It observed from the life-form spectra that Hemicryptophytes (H) was the most common dormancy form at 44.8%. Geophytes (G), Epiphytes (E), Hydatophytes (HH), Therophytes (Th) and Chamaephytes (Ch) were calculated at 26.1%, 10.5%, 4.5%, 0.8% and 13.4%, respectively.

• Journal of Ginseng Research
• /
• v.32 no.2
• /
• pp.155-160
• /
• 2008

The North American ginseng (Panax quinquefolius L.) seed crop varies from year to year. The ability to hold stratified seed for a year would ensure continuity of seed supply and no interruption in production cycles. Seed drying and rehydration protocols at room temperature $(21{\pm}2^{\circ}C)$ were developed. These protocols and seed storage at 4 ${\pm}1^{\circ}C$ and 35%, or variable, relative humidity (RH) allowed the holding of stratified seed for one year and then establishment of the following five treatments in field plots: Trt.1 : dried 2005 stratified seed (seed harvested Fall 2004) held at $4^{\circ}C$ and at variable humidity; Trt.2 : 2006 stratified seed planted directly into the field; Trt.3 : 2005 stratified seed dried in October 2005 and held at $4^{\circ}C$ and 35% RH ; Trt.4 : 2005 stratified seed held in moist sand from October to December 2005 at room temperature $(21{\pm}2^{\circ}C)$ and then in December dried and held at $4^{\circ}C$ and 35 % RH; Trt.5 : 2005 stratified seed held in moist sand from October to December 2005 at room temperature and then in December dried and held at $-12^{\circ}C$ Seedling emergence was best in Trts. 2 and 4 with 67.3 and 65.1% respectively which is similar to the industry expected rate of 68% after regular stratification. Seedling growth was similar in Trts. 2 and 4 with root dry weights of 172 and 159 mg respectively in mid-August. Therefore, if holding stratified seed in August/September for one year is desired, the seed can be placed in moist sand until December and then dried and stored at $4^{\circ}C$ and 35% RH. These seed can be planted in the following August/September and will germinate and grow in the following year to give an acceptable crop.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.23 no.1
• /
• pp.15-36
• /
• 2020

The purpose of this study is to provide basic data for the establishment of the management plan of Seoullo 7017 after analyzing the characteristics of immigration plants in addition to those introduced plants. The taxa number of plants appeared as 276 taxa including 82 families, 161 genera, 246 species, 1 subspecies, 22 varieties and 7 forms. Among them, immigration plants appeared 79 classification groups, including 32 families, 65 genera, 77 species and 2 varieties. Invasive alien plants appeared as 22 classification groups in 79 classification groups of immigration plants. The ratio of America origin plants, second period(1932~1960) in introduction time and the wide diffusion species is high. In June, the growth and occurrence time of the immigration plants was the highest by monthly the characteristics of the growth of the immigration plants, the immigration plants appeared mostly. In case of dormancy form among life-form, the therophytes(th), in the propagation form-radicoid form, the R₅(monophyte), in the propagation form-disseminule form, the gravity D₄(having no special modification for dissemination), and in the growth form, the erect form(e) was high. The various immigration plants appeared in green areas covered by Zoysia japonica and low Hedera helix densities. This study is the first flora study since Seoullo 7017 was opened in 2017. And so continuous flora monitoring is required for Seoullo 7017.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.6 no.4
• /
• pp.235-241
• /
• 2004

There is a growing concern about the possible increase in inter-annual variation of minimum temperature during the winter season in Korea. This view is strengthened by frequently reported freezing injury to dormant fruit trees, while warmer winters have prevailed recently. The January minimum temperature record at fourteen weather stations was analyzed for 1951-2000. The results showed no evidence of increasing standard deviation at 3 locations between 1951-1980 and 1971-2000, while the remaining 11 stations showed a trend of decreasing standard deviation for the two periods. An empirical model explaining the spatial variation of the standard deviation was derived by regression analysis of 56 stations' data for 1971-2000. Daily minimum temperature and the site elevation may account for 68% of the observed variations. We applied this model to restore the average standard deviation of the January minimum temperature for 1971-2000, and the result was used to produce gridded minimum temperature data for the recurrence interval of 10 and 30 years at 250m resolution. A digital form of the plant hardiness zone map may be developed from this product for site-specific selection of adapted plant species.

• Korean Journal of Weed Science
• /
• v.8 no.1
• /
• pp.9-14
• /
• 1988

Three varieties of Echinochloa crus-galli (L.) Beauv. and five collections different in gross morphology from the E. crus-galli species were obtained in a lowland rice field located in Jukjeol-Ri, Soyang-Myeon, Wanju-Kun, Jeonbug to compare the ecological and physiological characteristics. There were great variations in seed dormancy, relative growth rates, days required to panicle emergence and panicle morphology among the collections. On the basis of the cluster analysis using the different characteristics, the collections were divided into three groups; E. crus-galli var. frumentaceae and its two ecotypcs, E. crus-galli var. echinata and its two ecotypes, and E crus-galli var. crus-galli and its one ecotype. There were differential responses in percent germination and post-germination growth of the collections to butachlor (2-chloro-2', 6'-diethyl-N-butoxymethyl acetanilide).

• Forest Science and Technology
• /
• v.14 no.4
• /
• pp.160-168
• /
• 2018

The seeds of Elaeocarpus serratus, a tropical underutilized fruit tree are characterized by hard seed coat and consequent poor water uptake and low germination. To improve the regeneration through seeds, various parameters such as viability of seeds, water uptake, and effect of seed mass on germination and pretreatments were performed using a completely randomized design (CRD). Tetrazolium (TZ) test was conducted using fresh, mature seeds revealed $50{\pm}2.56%$ mean viability. Seeds of different weight classes showed similar pattern of water uptake and the saturation level was achieved at 60 hrs of soaking. Seeds belong to weight class 2.6-3.5g were germinated ($12.5{\pm}1.26%$) with $175{\pm}1.75days$ (d) of mean time taken for germination (MTG). Germination capacity of seeds varied significantly among different populations and Varkala population gave $12.5{\pm}1.1%$ germination with $174.6{\pm}2.5d$ MTG. Among various seed treatments, mechanical scarification was superior in germination and significant reduction in MTG ($p{\leq}0.05$). The mechanical scarification by complete removal of seed coat resulted in $49.2{\pm}1.52%$ germination within a short period of time ($9.52{\pm}0.89d$ MTG). However, the complete removal of seed coat without damaging to embryo is a difficult task. An alternate treatment (Mechanical scarification II) by making cracks on nut faces vertically followed by soaking in distilled water for 24 hrs gave $48.4{\pm}1.73%$ germination with significantly reduced MTG ($12.14{\pm}0.56d$) over unsoaked, untreated control ($6.5{\pm}1.84%$ germination and $197.18{\pm}1.79d$ MTG; $p{\leq}0.05$). This treatment (Mechanical scarification II) is therefore recommended for E. serratus seeds as it can adopt easily and can achieve 7 fold increases in germination over control. The recorded germination through mechanical scarification is in tune with realized viability percentage of the seeds.

• Korean Journal of Breeding Science
• /
• v.41 no.1
• /
• pp.61-67
• /
• 2009

"Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.4
• /
• pp.266-270
• /
• 2009

This experiment was conducted to investigate the effect of transfer date to a growth chamber and low temperature on growth and flowering of Jeffersonia dubia for free control of flowering period. According to transfer date, any plant did not sprout when plants were put in a growth chamber from Aug. 20 to Dec. 20. However, all the plants which were put in a growth chamber on Jan. 20 or Feb. 20 sprouted and resulted in flowering. The effect of beginning time and period of low temperature treatment were also observed. At the beginning time of Aug. 20, sprouting and flowering occurred as plant received more than 60 days of low temperature treatment. However, almost of al l the plants sprouted and flowered by only 30 days of low temperature treatment when the low temperature was given after Sep. 20. 60 days of low temperature given again after about three month growing period after dormancy breaking, resulted in resprouting of all plants and 70% of them flowered in this experiment.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.15-15
• /
• 2019

The walnut (Juglans regia L.), a member of the Juglandaceae, is native to the mountain ranges of central Asia. This species of walnut is valued commercially for its nuts and in some areas for its timber. The seeds of walnut are recalcitrant and it has strong integument dormancy and their germination is irregular, making its natural propagation difficult. Low percentage of seed germination and long propagation cycle are the main problems of propagation. This study was conducted medium composition on in vitro plantlet regeneration from axillary buds of walnut. It has proved to be the most generally applicable and reliable method of in vitro propagation. Micropropagation culture that axillary buds are excised aseptically enables faster multiplication of plants. The axillary buds of walnut new cultivar "Sinlyeong" were cultured on two basal media which contained the different plant growth regulators depending on the respective shooting and rooting stage. After 12 weeks, the shoot generation rate was 85.3%, the shoot number and its length were 1.9/explant and 2.7 cm in the most favorable medium composition. The percentage of rooting was 25.4%. From these results, it was found the optimum basal medium and plant growth regulator for in vitro plant regeneration from axillary buds of walnut new cultivar "Sinlyeong". However, we have continued to search the other medium additives to enhance the rate of walnut root.