• Journal of the Korean Society of Tobacco Science
• /
• v.14 no.2
• /
• pp.104-115
• /
• 1992

The present study was conducted to compare the relative efficiency of four different breeding methods in tobacco varietal development. A single Fl hybrid plant from cross of two flue-cured cultivars of Nicotiana tabacum L Bright Yellow 4(BY4) and NC95, was selfed. F2population above cross was screened for resistance against bacterial wilt caused by Pseudommonas solanacearum E.F.Smith under the naturally infested field conditions, and the 30 lines were developed from F2 individual plant by anther culture (ADH), maternal method utilizing Nicotiana afpicana (MDH), single- seed descent(SSD) and Bulk breeding method, respectively. All characters except content of total alkaloids of ADH and MDH which wore bred by haploid methods reduced more than that of lines bred by conventional methods(SSD & Bulk) : however, the yields were 8% lower than other lines. The total alkaloid content of ADH was higher than that of MDH, and yield was reduced about 4n even though the number of leaf was identical with the MDH. All other characters of ADH were also reduced significantly. In the lines bred by conventional methods, population developed by SSD showed significantly wider leaf width, shorter plant height, later days to flower, and lower in percent reducing sugar than those by Bulk. The populations derived from haploid method showed greater phenotypic variance and wider range of variation than conventionally developed ones. The results obtained indicate that selection will provide a significantly greater genetic gain for leaf number and leaf length in the ADU and MDH populations, and for plant height and days to flower in the SSD and Bulk populations.

• Korean Journal of Environmental Agriculture
• /
• v.27 no.4
• /
• pp.356-361
• /
• 2008

Chrysanthemum indicum L. (Gamgug) has been examined to study their flowering habits, yields and bioactive compounds under different planting densities and mowing dates. The planting density experiment revealed a significantly increasing stem diameter, number of flowers and branches with decreasing plant density in the $100\;cm{\times}30\;cm$ and $130\;cm{\times}30\;cm$ treatments as compared to $70\;cm{\times}30\;cm$ treatments, but not plant height, leaf and flower width. On the other hand, the mowing date experiment showed that growth characteristics of plants were similar to the control plants (not mowing) and June 20 treatment, but July 20 treatments had significantly smaller than the control. The weights (g $plant^{-1}$) of dry flowers were affected by the planting density and mowing date. The flower yield of $586\;kg\;ha^{-1}$ obtained at $100\;cm{\times}30\;cm$ density was 11% and 22% higher than that of $120\;cm{\times}30\;cm$ and $70\;cm{\times}30\;cm$ treatments, respectively. The yield of dry flowers in the control and June 20 mowing date ranged $495-508\;kg\;ha^{-1}$, which is 40-42% higher than the yield in the July 20 treatments. The amount of essential oil (g $plant^{-1}$) in medically valuable flowerheads of C. indicum L. was statistically different between mowing dates but not among planting densities. The study showed that planting density and the mowing date could increase yields of flowerheads. An optimum planting density of $100\;cm{\times}30\;cm$ and mowing date of on or before June 20 is recommended for C. indicum L.

• Korean Journal of Plant Resources
• /
• v.19 no.3
• /
• pp.427-431
• /
• 2006

In vitro high-frequency plant regeneration of Muscari comosum var. plumosum through somatic embryogenesis was obtained via two developmental pathways: direct embryos and multiple shoots regenerated from embryogenic callus. Flower bud with pedicel, receptacle, petal and ovary wall, floral stalk and leaf as explants were cultured in MS medium supplemented with various plant growth regulators. Embryos formed directly from pedicel, receptacle and floral stalk. Depending on explant sources, the optimal medium was MS medium supplemented with 0.2 mg/L IBA and 0.3 mg/L BA, 3.0 mg/L IBA and 3.0 mg/L BA, and MS-free medium for pedicel, receptacle, and floral stalk, respectively. Multiple shoots regenerated from embryogenic cal]i which was initiated from petal, ovary and leaf were observed in MS medium with different concentrations and combinations of hormone. The most suitable medium for each type of explant was 3.0 mg/L IBA and 3.0 mg/L BA(petal and ovary) and 5.0 mg/L IBA and 5.0 mg/L BA (leaf) Furthermore, the combination of 0.1 mg/L 2,4-D and 1.0 mg/L BA was also good for all sources of explants not only for direct embryo formation, but also, for embryogenic callus induction.

• Korean Journal of Plant Resources
• /
• v.23 no.3
• /
• pp.228-232
• /
• 2010

The present study was carried out to elucidate the effect of girdling on the quality and harvest date of the 'Shigyoku' grapes. Among girdled vines, the interval from full bloom to harvest date was 77 days; this was as much as seven days shorter in vines receiving a 20% girdling treatment. With regards to fruit characteristics, significant differences were observed in cluster length, berry number, and berry weight in vines that received girdling treatments. There were also significant differences in cluster weight; 468.2 g, 491.6 g and 504.9 g in the control group, 10% girdling group, and 20% girdling group, respectively. Thus, the use of girdling treatments is an effective approach to increasing cluster weight by 5% in the 10% girdling treatment and 8% in the 20% girdling treatment. The 10% girdling treatment showed significant difference in terms of titrable acidity; in fact, the overall titrable acidity was relatively high among all the girdling treatments. The concentration of anthocyanin increased in 20% girdling treatment, but there were no significant differences in anthocyanin concentration among girdling treatments. Berry color developed rapidly in vines that received girdling treatment.

• Korean Journal of Medicinal Crop Science
• /
• v.4 no.1
• /
• pp.38-46
• /
• 1996

These studies were conducted to know the any differences in growth characteristics and root quality due to flower color and culture periods in Chinese bellflower. White flowered lines had tendency of increasing in growth characters such as stem numbers, capsule numbers and seed yield per plant, plant height, and root characters such as root weight, root length and root diameter even though statistically not significant. No differences were observed in saponin and essential oil contents between them. Three years old plants had more stems and capsules per plants, root weight and root length than two years old plants while no difference in saponin and essential oil contents between them. Saponin content was gradually decreased while essential oil content was clearly lowed in the roots from plants cultured more than 3 years even though no differences in stem and capsule numbers per plant and plant height.

• Journal of Ecology and Environment
• /
• v.46 no.1
• /
• pp.62-75
• /
• 2022

Background: Pollinators help plants to reproduce and support economically valuable food for humans and entire ecosystems. However, declines of pollinators along with population growth and increasing agricultural activities hamper this mutual interaction. Nectar and pollen are the major reward for pollinators and flower morphology and volatiles mediate the specialized plant-pollinator interactions. Limited information is available on the volatile profiles attractive to honey bees and bumblebees. In this study we analyzed the volatile organic compounds of the flowers of 9 different plant species that are predominantly visited by honey bees and bumblebees. The chemical compositions of the volatiles were determined using a head space gas chromatography-mass spectrometry (GC-MS) method, designed to understand the plant-pollinator chemical interaction. Results: Results showed the monoterpene 1,3,6-octatriene, 3,7-dimethyl-, (E) (E-𝞫-ocimene) was the dominating compound in most flowers analyzed, e.g., in proportion of 60.3% in Lonicera japonica, 48.8% in Diospyros lotus, 38.4% Amorpha fruticosa and 23.7% in Robinia pseudoacacia. Ailanthus altissima exhibited other monoterpenes such as 3,7-dimethyl-1,6-octadien-3-ol (𝞫-linalool) (39.1%) and (5E)-3,5-dimethylocta-1,5,7-trien-3-ol (hotrienol) (32.1%) as predominant compounds. Nitrogen containing volatile organic compounds (VOCs) were occurring principally in Corydalis speciosa; 1H-pyrrole, 2,3-dimethyl- (50.0%) and pyrimidine, 2-methyl- (40.2%), and in Diospyros kaki; 1-triazene, 3,3-dimethyl-1-phenyl (40.5%). Ligustrum obtusifolium flower scent contains isopropoxycarbamic acid, ethyl ester (21.1%) and n-octane (13.4%) as major compounds. In Castanea crenata the preeminent compound is 1-phenylethanone (acetophenone) (46.7%). Conclusions: Olfactory cues are important for pollinators to locate their floral resources. Based on our results we conclude monoterpenes might be used as major chemical mediators attractive to both honey bees and bumblebees to their host flowers. However, the mode of action of these chemicals and possible synergistic effects for olfaction need further investigation.

• Journal of People, Plants, and Environment
• /
• v.23 no.1
• /
• pp.87-99
• /
• 2020

This study was conducted to analyze the current state and symbolic meanings of floral emblem designation in local governments of South Korea. The scope of local governments subject to analysis was limited to special city, metropolitan city, province, self-governing province, city, self-governing city, county and district based on their administrative divisions. The floral emblems of local governments and their symbolic meanings as of 2019 were examined. A total of 44 plant species were designated as floral emblems. Many plant species with high designation frequency were included in Rhododendron spp., Rosa spp., Camellia spp., Magnolia spp., and Prunus spp.. Plant species with higher designation frequency tended to have more symbolic meanings. A total of 155 terms were used for the symbolic meanings assigned to all the designated floral emblems. The major symbolic meanings were relevant to material affluence or economic growth, community spirit, and personality generally required from local residents. Most of the plant species linked to the top 10 most frequently assigned terms in symbolic meaning were those of the top 10 most frequently designated floral emblems. In the case of floral emblems with high designation frequency, it was shown that they were linked with various symbolic meanings in order to grant identity with regional distinctiveness and differentiation, regardless of the symbolic meaning that the designated flowers generally have. However, the floral emblems with low designation frequency seem to have relatively strong physical or emotional relevance with local governments and thus are expected to have high utilization in regional branding and tourism marketing.

• Journal of Bio-Environment Control
• /
• v.8 no.2
• /
• pp.75-82
• /
• 1999

This study was carried out to examine the effect of day/nignt temperatures during seedling culture on the vegetative and reproductive growth of Lycopersicum esculentum ‘Seokwang’. The study was consisted of two culture stages, plug seedling production in the growth chamber and hydroponic culture of the plant in a glasshouse. Experiments were replicated over time. The germinated seedlings were raised for 33 days (experiment 1) and 35 days (experiment 2) in 4 growth chambers, each with day/night temperatures of either $25^{\circ}C$/$25^{\circ}C$, 16$^{\circ}C$/16$^{\circ}C$, 16$^{\circ}C$/$25^{\circ}C$ or $25^{\circ}C$/16$^{\circ}C$. Cool-white fluorescent lamps provided 140$\mu$mol.m$^{-2}$ .s$^{-1}$ light for 12h each day. In the second experiment, all chambers were supplied with 1000$\mu$mol.mol$^{-1}$ CO$_{2}$ during the photoperiod and had an air velocity of 0.3m.s$^{-1}$ and relative humidity of 80%. Plug seedlings raised were transplanted to rockwool slabs in a glasshouse and were grown hydroponically using the same nutrient solutions used for seedling culture for 37 days (experiment 1) and 35 days (experiment 2). Plant height was affected more by mean daily temperature than by interaction of day and night temperatures. Plant height was the highest in 16/16$^{\circ}C$ treatment. Leaf count was not affected by day and night temperatures, and the chlorophyll concentration was the highest in 16/$25^{\circ}C$ treatment. Fresh and dry weights of stem tended to be greater in treatments of constant day and night temperature. The number of node on which first and second flower clusters were set was significantly higher in 25/$25^{\circ}C$ treatment than in the other treatments. Days to flower of the first flower on the first flower cluster were the greatest in 25/$25^{\circ}C$ and the least in 16/$25^{\circ}C$ treatment. Vegetative and reproductive growth, such as height, fresh and dry weights, days to flower, and nodes of the 1st and 2nd flower cluster set were affected by day/night temperatures.

• Journal of Plant Biotechnology
• /
• v.33 no.1
• /
• pp.49-56
• /
• 2006

Gerber (Gerbera hybrida) is a valuable ornamental species grown as a potted plant and cut flowers. However, genetic variability within the gerbera genus is very limited. So it is absolutely needed to introduce and widen genetic resources into gerbera lines by genetic transformation. For the purpose, 18 Korean gerbera lines were screened to establish Agrobacterium-mediated genetic transformation procedure. In an experiment to select Korean gerbera lines which are amenable to Agrobacterium-inoculation, 12 lines turned out to be positive in Agrobacterium-inoculation. More callus were produced from BA 2ppm, Zeatin 2ppm, IAA 0.2ppm in pre-culture and regeneration medium (2X media) but there was no difference in the frequency of GUS expression rate. In another experiment to find out optimal condition for highly efficient Agrobacterium-inoculation, petiole and leaf explants have been treated with four different pre-culture periods, two different co-culture periods and two different Agrobacterium strains. As a result, high GUS expression has been showed from petiole and leaf explants treated no pre-culture period with LBA4404 Agrobacterium tumerfaciens, 5 day co-culture period and dipping treatment.

• Horticultural Science & Technology
• /
• v.32 no.2
• /
• pp.269-275
• /
• 2014

A standard rose cultivar, 'Love Letter' was selected for cut flower from the progenies of a cross between 'Red Giant' and 'Ensemble' by the rose breeding team of the Gyeonggi-do Agricultural Research & Extension Services (GARES) in 2011. A standard rose cultivar 'Red Giant' with red colored (RHS Red Group 45C) petals and 1.8 prickles per stems of 10 cm was used as a mother plant. A standard rose cultivar 'Ensemble' with white and red purple colored (RHS White Group 155C + RHS Red Group N57B) petals and 2.4 prickles per stems of 10 cm was used as a pollen parent. 'Love Letter' was crossed in 2007 and seedlings were produced. After tests of specific characters from 2008 to 2011, this cultivar was finally selected and named. As a standard type with large sized flower, it has red colored (RHS Red Group 46A) petals with 9.3 cm flower diameter and 32.4 petals per flower. Vase life of this cultivar could be as long as 12 days. It takes 43 days from pruning to blooming and cut flower productivity was 152 stems/$m^2$ in a year. The stems of cut flower have no thorn and the length is about with 70.5 cm. When this cultivar grew below $15^{\circ}C$ and 1,000 lux, the petals color became dark red in winter season. 'Love Letter' was registered as a new cultivar on Korea Seed & Variety Service (KSVS) with No. 4482 on May 8, 2013.