• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.678-686
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• 1997

This experiment was carried out to develop the mass propagation system for producing plug plantlets using stem cuttings of virus-tree microtubers in potato. Cocopeat, vermiculite, perlite and peatmoss were combined and used as plug nursery media to find out the best combination suitable for the growth of seedlings derived from microtubers. Seedling growth was favored in high temperature (above 2$0^{\circ}C$) and a long-day photoperiod(above 16 hours) condition, while stolons and microtubers formed in outdoor condition. Shoot and root multiplication was not affected by NAA 10mg /1 or IAA 10mg /1 treatment. At the early growth stage of plug plantlets, the number of leaves and roots and the length of root increased significantly when nodes from the upper (near to apex) part of shoots rather than from basal part were taken. But after transplanting, these differences among these characters were not observed. At ninety days after transplanting the plug plantlets in spring time, plant was around 70 to 80cm in height, and the number of stolons and tubers were ten and seven, respectively.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.149-152
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• 2001

Leaf chlorophyll fluorescence capable to estimate $CO_2$ assimilation was compared among three citrus rookstocks: trifoliate orange (Poncitrus trifoliate L.), 'Flying Dragon' (Poncitrus trifoliate L. var. monstrosa) and citromelo (Poncitrus trifoliate L.${\times}$Citrus paradisi), as well as among satsuma mandarin (Citrus unshiu cv. Nichinan No.1) grafted on the 3 rootstocks. Citromelo, the most vigorous rootstock; and 'trifoliate orange'; the most common cultivar and moderate rootstocks gave the same potential and actual quantum yields, whereas 'Flying Dragon' (very dwarf) had lower values due to a higher Fo and Fs for fluorescence obtained from dark-adapted and light-adapted leaves, respectively. These findings show that the absorbed photon energy was dissipated more as fluorescence from the antena chlorophyll in 'Flying Dragon' than trifoliate orange or 'swingle' citrimelo. The satsuma mandarins grafted on these rootstocks did not, however, show the differences observed in the rootstocks by having all the same potential and actual quantum yields. It is suggested that the rootsocks do not potentially or actually electron transport in the Photosystem II (PS II) of satsuma mandarin grafted on the 3 rootstocks.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.15-23
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• 2016

A study was conducted to evaluate the effects of irrigation (amount, interval) on tree growth, fruit quality, and cracking of organic 'Campbell Early' grapevine in 2012 and 2013. Three irrigation treatments were applied using a sprinkler system from mid-June to mid-August in 2012 and 2013, as follows: 10 mm was applied daily (10 mm-IR), 20 mm was applied every two days (20 mm-IR), and 30 mm was applied every five days (30 mm-IR). Soil electrical conductivity (EC) and temperature were found to be greatest in the 10 mm-IR treatment in both years. Soil moisture content ranged between 20-40% in the 10 mm-IR, between 20-60% in the 20 mm-IR, and between 20-70% in the 30 mm-IR treatment plots. The total number of leaves per shoot and shoot growth were found to be greatest in the 20 mm-IR and 30 mm-IR treatments, respectively. Cluster and berry weights, and cluster and berry sizes were not consistently affected by the treatments. The 10 mm-IR treatment resulted in an increase in fruit SSC, SSC/acidity ratio, and berry skin pigmentation ($b^*$; blue). Approximately 5% of fruit cracking was observed on average over both years in the 10 mm-IR-treated fruit, while the 30 mm-IR treatment resulted in nearly 18% of cracking in 2012. Average marketable fruit yield per year over two years was greatest for the 10 mm-IR treatment ($24.4t{\cdot}ha^{-1}$) followed by the 30 mm-IR treatment ($22.7t{\cdot}ha^{-1}$) and lastly the 20 mm-IR treatment ($22.2t{\cdot}ha^{-1}$). Thus, the 10 mm-IR treatment represents a suitable irrigation regimen for controlling leaf and shoot growth of vines grown under a rain-shelter system in sandy loam soils, while improving fruit sugar contents and skin color and limiting fruit cracking.

• Proceedings of the Turfgrass Society of Korea Conference
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• 2002.02a
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• pp.3-5
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• 2002

This study was carried out to get better understandings about morphological, ecological, and genetical characteristics of annual bluegrass collected from different golf courses in Korea and eventually to establish a successful control strategy. Twenty five local lines of annual bluegrass collected from 20 golf courses in Korea were classified into annual or perennial type on the basis of morphological characteristics. Twelve local lines showing obvious morphological differences were selected and then genetically assessed using RAPD analysis. Classification of the 12 local lines through RAPD analysis were considerably similar to that determined by both of morphological differences and phenotype. Responses of the two types of annual blugrass to herbicides were also examined. Shoot growth of annual bluegrass was significantly suppressed by flazasulfuron and the annual type was more susceptible than perennial type, regardless of flazasulfuron concentrations used. By pendimethalin treatment, there was no clear difference in susceptibility between the two types of annual bluegrass. However, by the treatment of dithiopyr, annual type was more sensitive than perennial type in both shoot and root growth. Nine tree species were screened to detect their allelopathic potential on turfgrasses and annual bluegrass. Acacia (Robinia pseudo-acacia) leaves showed selective inhibition in the shoot and root growth as well as their seed germination when treated with 2% and 10%(v/v) of the extract. However, the other leaf extracts except acacia inhibited non-selectively the growth of three turfgrass species such as bentgrass, perennial ryegrass and zoysiagrass and annual bluegrass. The PAL activities of annual bluegrass increased at 24 h after treatment of acacia leaf extract and peaked at 36 h and then decreased till 60h. The highest PAL activity was observed at 36h after treatment of 10%. The highest activity of CA4H in annual bluegrass was observed at 2h after treatment of acacia extract and the level was 4 times greater than that of the control. The phenolic acids such as p-coumaric acid, salicylic acid and ferulic acid were increased with the treatment of acacia leaf extract. The chloroplast membrane and cell wall of annual bluegrass were destroyed by treatment of acacia leaf extract and its inner materials were released. The membranes in annual bluegrass cells might be destroyed by phytotoxic compounds from acacia leaf extract.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.137-142
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• 1999

JC Raulston Arboretum of the North Carolina State University houses 113 species of Korean native landscape woody plants. Styrax japonicus 'Emerald Pagoda'[formerly 'Sohuksan'] is native to Korea, China, and Japan. 'Emerald pagoda' is a special cultivar found by DR. J.C. Raulston during the United States National Arboretum plant collection expedition of the island of Sohuksan at the Western end of the Korea in 1985. Incredible, thick, glossy, large-leafed form of this beautiful white flowering tree found in Korea in 1985. It was probably the most outstanding ornamental plant to come from the expedition after his trip to Sohuksan and Chindo in the harsh perilous islands of the coast of Korea. He brought this one back in his suitcase. Viburnum awabuki 'Chindo' is and evergreen broadleaf shrub. It is for screening and as fire resistant trees in the southern region of Korea, because of its compact, leathery leaves. 'Chindo' was discovered on the island of Chindo by the U.S. National arboretum plant exploration team including J.C. Raulston during its 1985 Korean trip. Cuttings were taken from this plant, and liners were produced over subsequent years. These liners are now being evaluated for hardiness and fruit production throughout the Southeast of USA.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.63-71
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• 2021

Windbreak forests, which have a windproof effect against strong winds, are known to be effective in reducing the spread of odors and dust emitted from livestock farms. The effect of reducing the spread of odors and dust can be estimated through numerical models such as computational fluid dynamics, which require aerodynamic coefficients of the windbreaks for accurate prediction of their performance. In this study, we aimed to evaluate the aerodynamic coefficients, Co, C₁, C₂, and α, of two windbreaks, Thuja occidentalis and a mesh net, through wind tunnel experiments. The aerodynamic coefficients were derived by the relation between the incoming wind speed and the pressure loss due to the windbreaks which was measured by differential pressure sensors. In order to estimate the change in the aerodynamic coefficient concerning various leaf density, the experiments were conducted repeatedly by removing the leaves gradually in various stages. The results showed that the power law regression model more suitable for coefficient evaluation compared to the Darcy-Forchheimer model.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.105-105
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• 2019

Dendropanax morbifera H.Lev is an evergreen tree that lives in subtropical climates. About 75 species of D. morbifera live in East Asia, but only one species live in Korea(Korean dendropanax). D. morbifera belonging to Aralicacae family 98% of D. morbifera are distributed in Jeollanam-do in the Korea and the grow wild in Gyeongsangnam-do and Jeju Island. The harvest time and usage of D. morbifera were recorded in traditional medicinal books. The roots and stems of D. morbifera had been used for traditional medicine to treat migraine, menstrual irregularity and skin disease. And D. morbifera leaves are contain flavonoids and polyacetylene compounds. In this study, we were investigated the physiological activity of D. morbifera by different areas collected at the same time, and compared to characteristics of plants. D. morbifera collected from Jeollanam-do (Goheung-gun), Gyeongsangnam-do (Namhae-gun) and Jeju Island, and dried at $50^{\circ}C$ for three days. We used dried D. morbifera powder for antioxidant tests. Each sample was extracted with hot water under the same conditions. The contents of total polyphenols and total flavonoids from D. morbifera were identified. Also, we performed to DPPH radical scavenging activity, ABTS cation radical scavenging activity and Superoxide anion scavenging activity efficacy for antioxidant activity determination. The contents of total polyphenols and total flavonoids in hot water extract of D. morbifera harvested from Gyeongsangnam-do and Jeollanam-do were higher than Jeju. However, D. morbifera harvested from Gyeongsangnam-do and Jeollanam-do showed no significant difference those content of total polyphenols and total flavonoids. And the antioxidant capacity was showed the similar patterns in antioxidant activity.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.3
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• pp.83-95
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• 2022

This study aims to present primary data for habitat restoration and artificial breeding conditions of L. unmunsana by identifying the habitat conditions and the larvae's food sources. In order to investigate the habitat characteristics of the adult L. unmunsana and land snails, which are the primary food sources for the larvae, field surveys were conducted on a total of 10 habitats in south-central parts of Korea including Sanseongcheon, Jeonju. The results revealed that the L. unmunsana habitat in the Sanseongcheon area had a broadleaf forest with a multi-layered vegetation structure, adjacent water features, and the north/northeast/northwest slopes with little effect of artificial lighting. The adult L. unmunsana in the Sanseongcheon area appeared from the end of May to the end of June, and was especially intensively observed around the middle of June. The most active time was from 23:30 to 00:30 with a temperature range of 19~22℃ and higher than 80% humidity. The peak count of the observed adults L. unmunsana was a total of 774 on June 11, 2021. In the case of land snails, 11 families and 23 species were observed in 10 habitats of L. unmunsana, and Euphaedusa fusaniana was the most extensive and the most observed in the five survey areas. The land snails of L. unmunsana habitats are mostly found under the organic layers of leaves and a fallen tree branch in broadleaf forests, where a thick organic material layer buffers temperature changes and provides high humidity for various snails. These habitat conditions are suitable for the larva of L. unmunsana and land snails to inhabit, feed, hide and hibernate.

• The Korean Journal of Mycology
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• v.49 no.4
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• pp.531-537
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• 2021

Styrax japonicus is a deciduous shrub or a small tree belonging to the family Styracaceae. Since 1990, a rust fungus has continuously been found on S. japonicus leaves across the country. The morphological characteristics of the rust fungus were most consistent with those of Pucciniastrum styracinum reported on Styrax obassia in Japan. The species identification was confirmed by molecular phylogenetic analysis of the internal transcribed spacer and large subunit rDNA sequences. The current study provides mycological information with morphological measurements and molecular phylogenetic data of P. styracinum found on S. japonicus in Korea. Therefore, this is the first confirmed report on the presence of P. styracinum on S. japonicus in Korea.

• Research in Plant Disease
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• v.29 no.3
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• pp.286-294
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• 2023

Biological and molecular characterization of a Korean isolate of Orthotospovirus chrysanthinecrocaulis (formerly known as chrysanthemum stem necrosis virus, CSNV) isolated from Chrysanthemum morifolium was determined using host range and sequence analysis in this study. Twenty-three species of indicator plants inoculated mechanically CSNV-Kr was investigated for determination of host range. CSNV-Kr induced various local and systemic symptoms in the inoculated plant species. CSNV-Kr could not infect three plant species and induced symptomless in systemic leaves in Nicotiana tabacum cultivars, though the plant samples reacted positively with the antiserum to CSNV by double-antibody sandwich-enzyme-linked immunosorbent assay. The complete genome sequence of CSNV-Kr was determined. The L RNA of CSNV-Kr consists of 8,959 nucleotides (nt) and encodes a putative RNA-dependent RNA polymerase. The M RNA of CSNV-Kr consists of 4,835 nt and encodes the movement protein (NSm) and the glycoprotein precursor (Gn/Gc protein). The S RNA of CNSV-Kr consists of 2,836 nt and encodes NSs protein and N protein. The Gn/Gc and N sequence of CSNV-Kr were compared with those of previously published CSNV isolates originating from different countries at nucleotide and amino acid levels. The Gn/GC sequence of CSNV-Kr shared 98.8-99.5% identity with CSNV isolated from other countries and the N sequence of CSNV-Kr shared 98.8-99.6% identity. No particular region of variability could be found in either grouping of viruses. All of the CSNV isolates did not show any relationship according to geographical origins and isolation hosts, suggesting no distinct segregation of the CSNV isolates.