• Horticultural Science & Technology
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• v.34 no.1
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• pp.142-153
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• 2016

The present study investigated identification of cultivars through phylogenetic analysis of 108 Citrus varieties and related cultivars using simple sequence repeat (SSR) markers. Two hundred three SSR primer pairs were used to detect polymorphic markers among 8 Citrus cultivars consisting of 4 mandarins, 1 orange, 1 tangor, 1 tangelo, and 1 pumelo. Eighteen SSR primer pairs were reproducible and showed highly polymorphic alleles. These markers were applied to assess genetic variations of the 108 varieties. Each marker detected 5-14 alleles, with an average of 9.28. The polymorphism information content varied from 0.417 to 0.791 with an average of 0.706. Cluster analysis with SSR markers resulted in 13 major groups reflecting cultivar types and pedigree information. Twelve orange cultivars in the $I-1^{st}$ sub-cluster and 23 mandarin cultivars in the $II-1^{st}$ sub-cluster, respectively, were not discriminated using the SSR markers. This could be due to narrow genetic backgrounds originated through bud mutation or nucellars seedlings. The SSR profile database of Citrus cultivars will be useful as a tool for protection of plant breeders' intellectual property rights in addition to assessing genetic diversity in Citrus cultivars and germplasms.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.556-559
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• 2009

"Hongso" was originated from a cross between "Yoko" and "Hongro" in NIHHS, RDA, in 1989. "Hongso" was preliminarily selected in 2002 for its high fruit quality. After regional adaptability test at five sites from 2003 to 2006 as "Wonkyo Ga-30" it was finally selected in 2006. Optimum harvest time is early September which is similar to that of "Hongro". Fruit shape is globose conical and skin color is light red. Mean fruit weight is 295g and soluble solids content is 14.1oBrix. Fruits acidity is 0.34%, which is higher than that of "Hongro"(0.23%). It has a good taste for harmony of sugar and acidity. Storability is 3 weeks in room temperature. It is apt to russet on fruit skin. It is susceptible to Bitter rot. "Hongso" has a good cross compatibility with major cultivars such as "Fuji", "Hongro" and "Tsugaru". Tree habit is semi-spreading and tree vigor is weak. "Hongso" is high-density cultivation type cultivar, because it has a precocity, spur-type.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.51-55
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• 2009

Jayoung was bred within the potato breeding program of Highland Agriculture Research Center (HARC), National Institute of Crop Science. It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. Jayoung was evaluated as a clone number Daegwan 1-104 for the growth and tuber characteristics, yielding ability, and resistance to major potato diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as Jayoung and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. Jayoung has a oval shape, shallow eye depth, dark purple skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.3 MT/ha, and it showed the highest yield in spring cropping. Jayoung showed high resistance to both common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to late blight (Phytophthora infestans). The dry matter content of Jayoung was fairy high 20.3%, therefore it is suitable for both chip processing and table usage. Its anthocyanin content was the highest in autumn cropping as 43.7 mg/100 g fresh weight and its mean anthocyanin content was 4.7 times higher than that of Jasim.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.354-357
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• 2009

"Wonkyo Na-heukseong 2" was selected from a cross between "Kiyomaro", late season European cultivar with highly resistance and "Mansoo", late season Asian cultivar with long storability, large size and low susceptibility to pear scab made in 1997 at the National Institute of Horticultural & Herbal Science of Rural Development Administration in Korea. "Kiyomaro", released cross between "Taiheiyo" and "Bartlett" with scab resistance caused by Venturia nashicola in Japan, with no visual symptoms on any leaves was used as scab resistant source after field investigation and artificial inoculation test during 1997~1999. "Wonkyo Na-heukseong 2" blooms 1 day earlier than "Mansoo" and 3 days later than "Kiyomaro" in 2008. It is strong in tree vigor and upright-spreading in tree habit. It is classified as highly resistant to pear scab as "Kiyomaro" and "Bartlett", and cross-compatible with parental variety and Korean major pear varieties such as "Niitaka" and "Wonwhang". The average optimum harvest time of "Wonkyo Na-heukseong 2" was approximately 180 days after full bloom and it matured about 20 days shorter than parental varieties. The fruit is spindle in shape and yellowish greenish brown in skin color. Average fruit weight was 484 g and soluble solids content was $13.2^{\circ}Brix$. The flesh had medium to high juice and negligible grit. Its fruit was crisp like Asian pear.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.699-702
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• 2010

Anthracnose is a major limiting factor of the watermelon production in Korea. A mid-late maturing watermelon line, 'Hanbit' with resistance to anthracnose (Colletotrichum orbiculare) race 1 and 3, was developed by the cross between anthracnose resistant cultivar 'AU-Producer' and high quality inbred line '920533' at the National Institute of Horticultural and Herbal Science, Rural Development Administration (RDA). 'Hanbit' produces 5.4 to 9.5 kg of red flesh fruits with clear stripes on skin. Average soluble solid contents are ranged from 10.4 to 11.2$^{\circ}$Bx. The yield and quality of 'Hanbit' was comparable to or better than those harvested from the popular commercial cultivars. 'Hanbit' can be cultivated in open fields and under the protected green house condition. In addition to the commercial production, it can be used as a resistant material in $F_1$ hybrid breeding program.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.502-506
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• 2009

"Hongyoung" was bred within the potato breeding program of National Institute of Highland Agriculture (NIHA). It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. "Hongyoung" was evaluated as a clone number Daegwan 1-102 for the growth and tuber characteristics, yielding ability, and resistance to major diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as "Hongyoung" and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. "Hongyoung" has a round shape, shallow eye depth, red skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.4 MT/ha, and it showed the highest yield in spring cropping. "Hongyoung" showed high resistance to common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to both potato virus Y (PVY) and late blight (Phytophthora infestans). The dry matter content of "Hongyoung" was low to medium 17.7%, therefore it is suitable for table use. Its anthocyanin content was the highest in autumn cropping with 31.8 mg/100g fresh weight and it contained 3.6 times higher anthocyanin than the control, Jasim.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.233-238
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• 2019

For greenhouse crops, thrips is one of the major insect pests, but its control is difficult owing to short generation time, rapid escaping behavior, and development of pesticide resistance. Stratiolaelaps scimitus (Womersley) is a soil-dwelling predatory mite attacking various soil invertebrate species, including thrips. Using the method by growers' self-production, we mass-reared S. scimitus colony and investigated thrips control in the greenhouse chrysanthemum. The initial density of thrips was six individuals/flower. The treatment with one S. scimitus box in the greenhouse was estimated to be $1,000individuals/m^2$. From August to September 2018, the greenhouse was released with a total of 10 boxes of S. scimitus. The density of thrips in the untreated and the treated cultivar was $53.7{\pm}7.0$ and $13.5{\pm}1.7$ on the late September, respectively, which indicated a reduction of 74.9% in the treated cultivar. Our results suggest that S. scimitus was highly effective for the control of thrips in the greenhouse chrysanthemum although temperature is very high during the summer season.

• Journal of Life Science
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• v.28 no.12
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• pp.1523-1528
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• 2018

This study investigated the chemical composition of four Korean cultivated Chrysanthemum indicum L. (Gamguk 1 ho, Gamguk 2 ho, Gamguk 3 ho, and Wonhyang) which are used in the food and fragrance industries to identify their volatile flavor compounds. These compounds were analyzed using headspace GC-MS from plant samples cultivated in the same region of Korea (Sancheong-gun, Gyeongsangnam-do). A total of 23 compounds were identified, eight of which were common across the four cultivars. The major flavor components in the three Gamguk plants were identified as 3-carene, camphene, ${\beta}$-phellandrene, eucalyptol and (+)-camphor. Eleven compounds, including (+)-camphor at 31.40%, were identified in Gamguk 1 ho. Gamguk 2 ho was found to contain 12 flavor compounds, predominant of which was camphene at 25.60%. Thirteen compounds including (+)-camphor (26.88%) were identified in Gamguk 3 ho, while 17 were detected in the Wonhyang cultivar, including trans-piperitol (47.33%), sabinene, and ${\gamma}$-terpinyl acetate. These results indicate differences in the type and ratio of functional volatile flavor ingredients in Chrysanthemum indicum L. cultivars which is highly valuable as material for fragrance product development.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.145-153
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• 2019

BACKGROUND: The 'Gamhong' cultivar, middle season apple with big fruit size and high soluble solid content, has been bred in Korea. However, it was hard to cultivate the cultivar in Korea by serious bitter pit. The relationships between shoot growth, fruit size, and bitter pit may be affected by crop load. This study was conducted for 2 years (7~8 years after planting) to investigate vegetative growth, fruit quality, bitter pit incidence, return bloom, and gross income for optimum crop load of 'Gamhong'/M.9 adult apple tree. METHODS AND RESULTS: The crop load was assigned to 4 different object ranges as follow: 45~64, 65~84, 85~104, and 105~124 fruits per tree. The vegetative growth, average fruit weight, percentage of fruits heavier than 375 g, soluble solid content, and return bloom increased significantly at the crop load range of 45~64 fruits. However, the lowest total gross income per tree may have been caused by the highest bitter pit incidence and the lowest yield per tree in any other crop load range. The total gross income and yield per tree increased significantly at the crop load range of 105~124 fruits and return bloom dropped to 40%, and hence it was possible to occur biennial bearing. It was 85~104 fruits that biennial bearing did not occur and total gross income was as high as the crop load range of 105~124 fruits. Also, the yield of high grade fruits per tree, with fruit weight of 400~499 g and none bitter pit on fruit surface, was highest at the crop load range of 85~104 fruits, compared to other crop load range. CONCLUSION: In considering fruit size, bitter pit incidence, return bloom, and gross income, the optimum crop load range of 'Gamhong'/M.9 adult apple tree in high density orchard was 85~104 fruits per tree.

• FLOWER RESEARCH JOURNAL
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• v.26 no.4
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• pp.216-220
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• 2018

Freesia (Freesia hybrida Hort.) 'Sweet Lemon' was developed for the cut flowers in National Institute of Horticultural Herbal Science, Rural Development Administration, Korea in 2015. This hybrid was crossed and selected from 'Teresa' and 'Yvonne' in 2007. Morphological characteristics of the selected freesia hybrid were investigated for 5 years from 2009 to 2014, and then it was named 'Sweet Lemon' in 2015. 'Sweet Lemon' has double and lemon petals (RHS color chart Y2B). The average flower diameter was 6.8 cm and the average yield is 6.7. The growth of the plant is vigorous and the average plant height is 99.0cm, which is 34.7cm higher than the standard cultivar 'Yvonne'. The average floret number per stalk of 'Sweet Lemon' was 10.7, and stalk length was 7.7 cm. The average days to first flowering of 'Sweet Lemon', 126 days, was approximately 20 days earlier than the control cultivar. It's average vase life and yield is 8.7 days and 5.6 cormlets per plant, respectively. Totally 58 of volatile compounds were identified using gas chromatography-mass spectrometry (GC-MS), the major components were linalool, alpha-terpineol, alpha-selinene, and limonene.