• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.236-240
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• 2010

'Jomang' is a new $F_1$ hybrid variety of rapeseed (Brassica napus L.) with early maturation, high yield and high oleic acid. This hybrid variety was developed from the cross between Mokpo-CGMS (male sterile line) and 8516-B-5-6-5-3 (restore line) for the production of edible oil and biodiesel in 2006. Yield trials were conducted from 2007 to 2008, and regional adaptation trials were examined at four locations in 2008. 'Jomang' has green and parted leaf, yellowish flower and black seed coat. The ripening date of 'Jomang' is 1~4 days earlier than 'Sunmang' and 'Tammiyuchae'. The average seed yield of the regional adaptation trials was 406 kg/10a, which was 7% and 42% higher than those of 'Sunmang' and 'Tammiyuchae,' respectively. Total oil content of 'Jomang' was 44.5%. 'Jomang' has no erucic acid in fatty acid composition. However, oleic acid content is 68.2%, which is 3.4% and 5.1% higher than 'Tammiyuchae' and 'Sunmang,' respectively. Total glucosinolate content was 2.31 mg/g. Therefore, this variety is recommended as a leading variety at southwestern area including Jeonnam, Jeonbuk and Kyongnam provinces and Cheju island of Korea.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.497-503
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• 2018

A strawberry variety 'Arihyang' was derived as an artificial cross between 'Tochiotome' and 'Seolhyang' in 2014. The seedling and line selections were conducted from 2014 to 2015. Preliminary and advanced yield trials of '14-5-5,' which was the final selected line, were conducted from 2015 to 2017. 'Arihyang' is suitable for forced cultivation and has strong plant vigor, uniformly large-sized fruit, and a high yield compared to those of the check variety, 'Seolhyang' and 'Maehyang.' Especially, vitamin C was at a significant level, which was approximately 15% higher than that of 'Seolhyang.' The average number of flowers per first flower cluster was 10.5, which could reduce the labor of thinning fruit. Its fruit has a conical shape, dark red color, and glossy skin. The fruit was of good quality but has recommendations for harvest at the fully ripened stage. 'Arihyang' has intermediate resistant to phytophthora crown rot, but is susceptible to powdery mildew, gray mold, anthracnose, and fusarium wilt. It is reguired to manage major diseases and pests using optimum cultivation techniques and chemical control.

• Korean Journal of Breeding Science
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• v.51 no.4
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• pp.318-325
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• 2019

Salt stress is a significant factor limiting growth and productivity in crops. However, little is known about the response and resistance mechanism to salt stress in maize. The objective of this research was to develop an enhanced salt-tolerant silage maize by mutagenesis with gamma radiation. To generate gamma radiation-induced salt-tolerant silage maize, we irradiated a KS140 inbred line with 100 Gy gamma rays. Salt tolerance was determined by evaluating plant growth, morphological changes, and gene expression under NaCl stress. We screened 10 salt-tolerant maize inbred lines from 2,248 M₂ mutant populations and selected a line showing better growth under salt stress conditions. The selected 140RS516 mutant exhibited improved seed germination and plant growth when compared with the wild-type under salt stress conditions. Enhanced salt tolerance of the 140RS516 mutant was attributed to higher stomatal conductance and proline content. Using whole-genome re-sequencing analysis, a total of 328 single nucleotide polymorphisms and insertions or deletions were identified in the 140RS516 mutant. We found that the expression of the genes involved in salt stress tolerance, ABP9, CIPK21, and CIPK31, was increased by salt stress in the 140RS516 mutant. Our results suggest that the 140RS516 mutant induced by gamma rays could be a good material for developing cultivars with salt tolerance in maize.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.423-430
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• 2024

Cymbidium (C.) spp. 'Wedding Day' was developed by the National Institute of Horticultural and Herbal Science, Rural Development Administration in 2021. This cultivar was derived from the artificial cross between C. 'Boksam Holiday' and C. 'Persicolor' in 2008. After the crossing, 112 seedlings were obtained through in vitro germination and transferred to the green house. Based on their vegetative and flowering characteristics, two lines were selected through the first selection. To confirm the stability and uniformity of the two lines, the first and second trials were conducted from 2017 to 2021. As a result, the final line with the code 'C0844-29' was selected as 'Wongyuo F1-78'. After evaluating consumer preference, the line was named as 'Wedding Day'. This hybrid is medium sized cultivar with long vase life of cut flowers and more than 11 white flowers per stalk. It has 63.2 cm of erect stalks which are suitable for cut flower. The leaves are 65.8 cm long and located lower than the flowers, providing appropriate shape for viewing the flowers. It starts flowering from late January. It has sufficient proliferation ability to enable mass proliferation for commercial use (Registration No. 9523).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.533-538
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• 2004

An introgression line, WH79006 was produced from a single plant from $BC_5F_3$ families from a cross between Hwaseongbyeo used as a recurrent parent and O. minuta (BBCC, Ace. No. 101154) as a donor parent, which was subsequently self-pollinated for three generations. WH79006 resembled the O. sativa parent, Hwaseongbyeo. However it differed from Hwaseongbyeo in several traits including days to heading, culm length, grain size, spikelets per panicle and fertility. These differences in the traits between WH79006 and Hwaseongbyeo can be attributed to the O. minuta introgressions. To detect the introgressions, 294 SSR markers of known chromosomal position have been used. At least, 28 introgressed chromosomal segments have been identified using SSR markers and they map to all chromosomes except chromosome 2. The size of the introgressed segments ranged from 4 to 35cM. A QTL related to culm length was detected using 75 $F_2$ plants from the Hwaseongbyeo/WH79006 cross. This QTL, cl6 located on chromosome 6 explained $9.6\%$ of the total phenotypic variation in the population. This QTL has not been detected in the previous QTL studies between Oryza sativa cultivars, indicating potentially novel alleles from O. minutan.

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.228-234
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• 1997

This study was carried out to confirm the taxonomical status by comparison of morphological and chromosomal charateristics and cross breeding in the two types of black and yellow body color of Korean mandarin fish, Siniperca sherzeri from Han River, Korea. Black and yellow types of Korean mandarin fish were similar in having 90-98 lateral line scale pores, 13 dorsal fin rays and XII XIII spines, 9 anal fin rays and 15 pectoral fin rays, but yellow type was differ from blacks type by yellow body color pattern. Diploid chromosome and arm number (fundamental number, NF) of the two types were the same to 2n=48 and NF=52. Karyotypes in the two types are consisted of 2 pairs submetacentric chromosome and 22 pairs of acro and/or telocentric chromosome. The black type females of Siniperca scherzeri were artificially crossed with yellow type males and black type males, respectively. The progenies from each cross breeding produced the normal individuls that possessed with parent types in the body color pattern. These data suggest that two types of Korean mandarin fish were same species, and yellow type was mutant by albino.

• Korean Journal of Plant Tissue Culture
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• v.24 no.4
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• pp.239-256
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• 1997

Plants belonging to the category of 2n apomixis or agamospermy form embryos and seeds without the processes of normal meiosis and syngamy. Seeds produced in this way have identical genotype of their maternal parent. Three different types of agamospermy are recognized: diplospory, apospory, and adventitious (adventive) embryony. $F_1$ hybrid cultivars cannot be used as seed sources in the next ($F_2$) generation because this generation would be extremely variable as a result of genetic segregation. Hybrid vigor is also reduced in the $F_2$ generation. Therefore, parental stocks for hybrid seed production need to be maintained and cross must be continuously repeated. Agamospermic 2n apomixis would make it possible to fix the genotype of a superior variety so that clonal seeds faithfully representing that genotype could be continuously and cheaply produced independent of pollination. That is, $F_1$ hybrid seeds could be produced for many generations without loss of vigor or genotype alteration. Production of apomictic $F_1$ hybrid seed would be simplified because line isolation would not be necessary to produce seed or to maintain parental lines, and the use of male-sterile lines could be avoided. Overall, apomixis would enable a significant reduction in hybrid seed production costs. Additionally, the production of clonal seed is not only important for seed propagated crops, but also for the propagation of heterozygous fruit trees and timbers. Clonal seed would help avoid costly and time-consuming vegetative propagating methods that are currently used to ensure the large-scale production of these plants. Apomixis is scattered throughout the plant kingdom, but few important agricultural crops possess this trait Therefore, most research to date has centered on introgressing the trait of apomixis into agricultural crops such as wheat, maize, and some forage grasses from wild distant relatives by traditional cross breeding. The classical breeding approach, however is slow and often impeded by many breeding barriers. These problems could be surmounted by taking mutagenesis or molecular approach. Arabidopsis thaliana is a tiny sexually reproducing plant and is convenient in constructing and screening in molecular researches. Male-sterile mutants of Arabidopsis are particularly suitable genetic background for mutagenesis and screening for apomictic mutants. Molecular approaches towards isolating the genes controlling the apomictic process are feasible. Direct isolation of genes conferring apomixis development would greatly facilitate the transfer of this trait to wide variety of crops. Such studies are now in progress.

• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.444-454
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• 2013

The development of random amplified polymorphic DNA (RAPD) and expressed sequence tag-derived simple sequence repeats (EST-SSRs) provided a useful tool for investigating Korean ginseng genetic diversity. In this study, 18 polymorphic markers (7 RAPD and 11 EST-SSR) selected to assess the genetic diversity in 31 ginseng accessions (11 Korean ginseng cultivars and 20 breeding lines). In RAPD analysis, a total of 53 unique polymorphic bands were obtained from ginseng accessions and number of amplicons ranged from 4 to 11 with a mean of 7.5 bands. Pair-wise genetic similarity coefficient (Nei) among all pairs of ginseng accessions varied from 0.01 to 0.32, with a mean of 0.11. On the basis of the resulting data, the 31 ginseng accessions were grouped into six clusters. As a result of EST-SSR analysis, 11 EST-SSR markers detected polymorphisms among the 31 ginseng accessions and revealed 49 alleles with a mean of 4.45 alleles per primer. The polymorphism information content (PIC) value ranged from 0.06 to 0.31, with an average of 0.198. The 31 ginseng accessions were classified into five groups by cluster analysis based on Nei's genetic distances. Consequently, the results of ginseng-specific RAPD and EST-SSR markers may prove useful for the evaluation of genetic diversity and discrimination of Korean ginseng cultivars and breeding lines.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.306-309
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• 2009

A New bicolor standard rose (Rose hybrida Hort.) cultivar were developed by line selection in 2000 at the Flower Research Institute, Gyeongnam ARES. Characteristics were investigated three times from 2003 to 2006 "Grandking" was crossed between 'Bixa' and 'Red Sandra' and it has a red-group color (RHS No. 52A), few thorns and standard large flower with a good harmony between ray floret and flower center. The vase life of cut flower was 12.8 days. The major characteristics of this variety are 228 stems/$m^2$/year in yield, 77.4 cm in length of cut flower, 9.0 cm in flower diameter, and 36.1 in petal number. It was registered as commercial cultivar in 2006. These new variety could be planted in almost greenhouse production region of Korea.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.595-598
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• 2009

A new yellow gerbera (Gerbera hybrida Hort.) cultivar "Golden Time" was developed from a cross between '99-ga-2' and '99-na-7-6', followed by seedling and line selections at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) in 2007. Detailed characteristics of the new cultivar were evaluated from 2004 to 2007. "Golden Time" has semi-double type large flowers in a good harmony with yellow (RHS, 17-B) ray floret and brown center. It has good, stable flower shape and strong peduncles, and its vase life was 12.3 days. The average flower yield of "Golden Time" was about 49.5 stems per plant/year in greenhouse trails during 2004 and 2007. This cultivar was registered to the Korea Seed and Variety Service (KSVS) for commercialization in 2009. Year-round production of this cultivar is possible in the greenhouse condition throughout the Korean climate.