• Korean journal of applied entomology
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• v.48 no.3
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• pp.327-333
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• 2009

Biological Characteristic of Obolodiplosis robiniae and insecticidal activity of some insecticides against larvae of O. robiniae were investigated. Egg was in oval shape, and its color was light orange and became red when close to hatch. Length of the major axis and the minor axis of egg was 0.4 mm and 0.1 mm, respectively. Larval color was milky and size was 2.6 mm. Pupa was deep brown and its size was about 3.2 mm. Wing and abdomen of adult was black and reddish, respectively. Size of female adult was about 3.3 mm, and larger than male adult. Number of eggs in the ovary was $192.3{\pm}50.7$. First emergence was from late April to late May, and second from late May to late June. Third emergence was from late June to late July. Newly emerged adult escaped from soil, and second and third emerged adult escaped directly from gall of Robinia pseudoacacia leaf. Egg parasitoid was identified as Platygaster robiniae and parasite rate was 51.6%. Among test insecticides, imidacloprid 10% WP and thiacoprid 10% FL showed very strong insecticidal activity against larvae of O. robiniae at 48h later after treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.194-200
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• 2014

Skin ridge (SR) is a irregular line shape that stand out in epidermal layer on sweet potato (Ipomoea batatas Lam.). SR reduced marketable value of storage root in sweet potato. It would be occurred by accumulation of starch in epidermal layer. SR rate was more highly increased in early planting. SR rate was under 3% in 7 varieties 'Geonpoongmi', 'Yeonhwangmi', 'Geonmi' etc and the rate of two varieties 'Healthymi', 'Borami' were up to 30%. SR rate was positively correlated with vine weight. SR rate was the highest in 120 days after planting. As leaf area index was reduced to 3, 4, 5 and 6 (non-topping) by topping, it was hard to fine SR occurrence in topping treated sweet potato. Topping treatment, however, caused decrease in yield overall. Therefore, topping treatment for decreasing of SR was not recommended in agricultural practice of sweet potato.

• Horticultural Science & Technology
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• v.17 no.4
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• pp.489-493
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• 1999

This study was conducted to investigate the potentiality of various Korean Sedum species as ornamental plants based on morphological characteristics and to analyze the genetic relationship among the Sedum species. S. kamtschaticum and S. takesimense possessing splendour flowercluster with yellow color could be suggested for garden plant, S. routundifolium having pink flower-clusters with round leaf shape for pot flower or garden plant and S. sarmentosum, S. polystichoides and S. oryzifolium with creeping stem and low plant height for ground cover plant or floral carpet. Eighteen oligonucleotide random primers were used to amplify genomic DNA of Sedum species using polymerase chain reaction (PCR). Ninety five polymorphic bands among 125 different DNA fragments in the range of 224 to 3,675 base pairs were obtained from RAPD analysis. Similarity matrix of RAPD profiles was generated by coefficient value of variation, and the data were subjected to be cluster analysis. Fifteen lines of Sedum species analyzed were classified into 3 groups with the similarity coefficient value of 0.418, and 12 groups with the value of 0.328. RAPD results showed similar trends as the morphological characteristics of the plants.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.298-301
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• 2015

A new Hibiscus syriacus variety, 'Dasom', was developed by radiation breeding using gamma ray exposure at the Korea Atomic Energy Research Institute (KAERI). Seeds of the original variety, 'Hongsun', were collected in 1993. These seeds were irradiated at 100 Gy dose and $M_1$ seeds were planted in a field of the KAERI in 1994. Lines with preferred flower color that were going to be used for street trees were initially selected in 1998. Analyses of characteristics were conducted from 2005 to 2010. The 5-year-old 'Dasom' plants were approximately 106 cm in height and averaged 19 branches, and thus were suitable for street trees. The flowers of 'Dasom' were semi-double type with medium red color and red eye spots. Petal length and width were about 4.0 cm and 3.3 cm, respectively. Flower diameter was slightly small, at about 5.8 cm, because of highly overlapping petals. The flowering period of 'Dasom' was about 105 days, which was 6 days shorter than that of the original variety, 'Hongsun'. However, the main charactersistics of 'Dasom' including leaf shape were similar to those of the original variety, 'Hongsun'.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.43-47
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• 2013

This study was conducted to develop the most effective method in promoting onion set in cultivars 'Josaengsseondebol' and 'Daeji' for all year-round production. This was done by extending the day length for 41 days. For both cultivars, the period to reach the maximum number of leaves developed was shortened as the exposure to day length increased. Between the two cultivars, 'Josaengsseondebol' reaches its maximum leaf formation for a shorter duration compared with 'Daeji'. In effect to bulb size, cultivar 'Josaengsseondebol' having a night break of 1, 2, and 16 hours light condition had better bulb enlargement compared with the non-treated bulbs. In the case of cultivar 'Daeji', only bulbs exposed to a night break of 2 and 16 hours light condition had better bulb enlargement. The percentage of marketable set yield in cultivar 'Josaengsseondebol' having a night break of 1 hr, 2 hrs, 16 hrs light condition, and control or untreated bulbs were 84%, 92%, 90%, and 6% respectively. In the case of cultivar 'Daeji', treated with a night break of 1 hr, 2 hrs, 16 hrs light condition, and untreated bulbs had a percentage marketable set yield of 7%, 55%, 64%, and 0% respectively. Based on these results, it is therefore concluded that night break treatment is considered to be effective method in promoting off-season onion set cultivation in cultivar 'Josaengsseondebol'.

• The Plant Pathology Journal
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• v.25 no.1
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• pp.86-90
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• 2009

In November 2008, typical powdery mildew symptoms were observed on leaves of Arabidopsis thaliana ecotype Col-0 plants in a growth room under controlled laboratory conditions at Korea University, Seoul. The disease was characterized by the appearance of white powder-like fungal growth on the surface of infected leaves. As the disease progressed, infected leaves exhibited chlorotic or necrotic brown lesions, and leaf distortion and senescence. Conidiophores of the causal fungus were hyaline, unbranched, 3-4 celled, cylindrical, and $80-115{\times}6-9{\mu}m$ in size. Singly produced conidia (pseudoidium type) were hyaline, oblong to cylindrical or oval in shape, and $26-55{\times}15-20{\mu}m$ in size with a length/width ratio of average 3, angular/rectangular wrinkling of outer wall and no distinct fibrosin bodies. Appressoria on the hyphae were multi-lobed. These structures are typical of the powdery mildew Oidium subgenus Pseudoidium, anamorph of the genus Erysiphe. The measurements of the fungal structures coincided with those of Erysiphe cruciferarum. The phylogenetic analysis using ITS rDNA sequences revealed that the causal fungus Erysiphe sp. KUS-F23994 is identical to E. cruciferarum. The isolated fungus incited powdery mildew symptoms on the inoculated Arabidopsis leaves, which proved Koch's postulates. Taken all data together, we first report the occurrence of powdery mildew disease of A. thaliana caused by Erysiphe cruciferarum in Korea.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.237-244
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• 1992

In order to observe the infectivity, growth and development and adult morphology of Metorchis orientalis, a total of 40 chicks were experimentally infected with 100 metacercariae respectively, collected from Pseuderasbora larva. The worms of various developmental stages were recovered from chicks at 1.5, 3, 5, 7, 9, 11, 1:k and 21 days after infection, and they were prepared for morphological observations and measurements. All of the worms were found in the gallbladders of chicks, and their recovery rate was 32% in average. The growth of the body was rapid from 9 to 11 days after infection. The genital primordia appeared in 1.5 and 3-day old worms, and ovary and testes were first observed in 5-day old worms. Thereafter, genital organs gradually matured and completed up to 11 days after infection. The adult worm was leaf-like, and possessed a con- voluted tubular seminal vesicle, an ovoid ovary, a sac-like seminal receptacle, 2 lobed-testes and follicular vitellaria. Eggs were $31.9{\times}15.3{\;}\mu\textrm{m}$ in average size, ellipsoid to elliptical in shape and possessed abopercular thickenings. From the above results, it is concluded that M. orientalis grows in sigmoid pattern in chicks, and their genital organs fully matul.e between days 9 and 11. It is also confirmed that a chick is a new definitive host of M. orientalis.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.784-787
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• 2012

'Gwanha' is new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar, which was released by Highland Agriculture Research Center, Rural Development Administration, in 2011. In 2007, this cultivar was originated from a cross between 'Sucambodiaberry' and 'Selva' that showed excellent ever-bearing characteristics including continuous pink flowering habit under long-day and high temperature condition. It was named 'Saebong No.4' after examining its characteristic and productivity in summer culture from 2009 to 2011. After characteristic and productivity test in 2011, 'Gwanha' was selected as an elite cultivar. The general characteristics of 'Gwanha' include spreading type, middle vigor, elliptic leaf, and long cluster in growth. The fruit shape is wedge, and the red fruit is edible and unique among the domestic ornamental strawberry cultivars. Flower color of 'Gwanha' is pink, and flower cluster is more appearance than 'Pinkpanda'. The average fruit weight of 'Gwanha' is about 7.8 g and the marketable yield is relatively low because of low marketable rate. It is resistant against fusarium wilt. 'Gwanha' is suitable for four season cultivation as an ornamental strawberry cultivar because it shows continuous flowering habit under long-day and high temperature condition.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.651-654
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• 2011

Cymbidium 'Orange Bowl' (Lucky Rainbow 'Randevous' ${\times}$ 'Eastern Star') was developed from a cross between hybrids at the National Institute of Horticultural & Herbal Science, Rural Development Administration in 2006. A cross was made between the pink colored flower C. Lucky Rainbow 'Randevous' as maternal line and pure yellow colored flower, C. 'Eastern Star' as paternal line in 1995. The seed germination, cultivation, selection, and characteristic trials were conducted from 1996 to 2006. The line was named as Wongyo F1-18 and phenotype was characterized in 2006 as a new 'Orange Bowl'. The 'Orange Bowl' has having light yellow basal color (RHS, YO21D) and orange line (RHS, OR30B) on both of sepal and petal with red lip (RHS, OR30B). 'Orange Bowl' has about 10.9 flowers per flower stalk and flower size of 7.4 cm. General appearance of the petals and sepals is slightly incurved shape. The plant size is intermediate having erect peduncle. Blooming is started from the late of January (mid winter) under optimal culture condition. Leaf attitude and twisting is half- erect and very weak respectively. This hybrid has attractive floral arrangement, long flower stalk (71.8 cm) and vigorous growth. We expect that 'Orange bowl' has a great potential for exporting to Chinese market.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.617-622
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• 2011

The study was conducted to determine the efficiency in producing spontaneous polyploids in some mandarin hybrids with different seed embryony. Seed formation by open pollination, frequency of spontaneous polyploids, and plant growth characteristics were evaluated in four mandarin hybrids with polyembryony such as 'Amakusa', 'Haruka', 'Hayaka', and 'Seminole' and two with monoembryony such as 'Benibae' and 'Harehime'. The mean number of the developed seeds per fruit was 10.0 and frequency of small seeds was 25.1%. Polyploids were selected from plants germinated in vitro by a flow cytometry and confirmed by chromosome analysis. One triploid was produced from 'Harehime', one tetraploid, 'Amakusa', and one tetrapoid, 'Benibae'. There were little differences in leaf shape, thickness, petiole length, and internode length between diploids and polyploids such as tri- or tetraploid. However, polyploids had larger stomata and lower density of stomata in abaxial epidermis than diploids. SPAS indicating chlorophyll content and photosynthetic rate were significantly affected by ploidy level. The results indicated that spontaneous polyploids might be produced by open pollination in some mandarin hybrids and monoembryony had higher frequency in polyploid occurrence than polyembryony.