• Horticultural Science & Technology
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• v.33 no.4
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• pp.550-558
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• 2015

To analyze the linkage relationships among molecular markers recently reported to be linked to onion (Allium cepa L.) Ms, a restorer-of-fertility locus, in onion (Allium cepa L.), three single nucleotide polymorphism markers were converted into cleaved amplified polymorphic sequence (CAPS) markers based on onion transcriptome sequences and the rice genome database. Analysis of the recombinants selected from 4,273 segregating plants using CAPS and other linked markers demonstrated the jnurf13 and jnurf610 markers to perfectly co-segregate with the Ms locus. In contrast to jnurf13, the jnurf610 marker was not in perfect linkage disequilibrium with the Ms locus in diverse breeding lines. Thus, the jnurf13 marker and the marker for identification of cytoplasm types were utilized to enhance the efficiency of onion breeding through four applications. First, 89 maintainer lines containing the normal cytoplasm and homozygous recessive Ms genotypes were successfully identified from 100 breeding lines. Second, these two molecular markers were used to analyze the main sources of male-fertile contaminants frequently found in the male-sterile parental lines during F1 hybrid seed production. The majority of the contaminants contained heterozygous Ms genotypes, indicating that pollen grains harboring the dominant Ms genotype may have been introduced during propagation of the maintainer lines. Therefore, the genetic purity of the two maintainer lines was analyzed in the third application, and the results showed that both maintainer lines contained 13-21% off-types. Finally, the two markers were used to increase the seed yield potentials of two open-pollinated varieties containing sterile cytoplasms by removing the plants harboring homozygous recessive and heterozygous Ms genotypes.

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.10a
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• pp.336-352
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• 1998

The horticultural seed industry has made great progress in the last fifty years of its history after the independence of this country. The industry has accomplished self-sufficiency in major vegetable seeds and has even gained international competitive edge in certain crop seeds, particularly in hybrid cultivar development. However, the industry is facing a crisis at present coming from excessive competition among the domestic seed companies as well as the foreign currency crisis of the country. Several major seed companies have already been acquired by multinational corporations. Many people in the country as well as agriculturists are concerned about this situation. Although it is true that the industry is undergoing hard times, this crisis can be turned into a chance for making new progress depending on the joint efforts of the groups responsible, i.e., private companies, public institutions, and policy makers. Therefore, we have to turn this crisis into an opportunity for self-reform and progress. We should not be discouraged or give up. We Propose some ideas for the Progress of the seed industry. Public institutions and policy makers should do such things in cooperation as 1) training human resources for future breeders, 2) securing a wide range of genetic resources and improvement of the management system, 3) basic science research including biotechnology, 4) releasing breeding stocks from germplasm enhancement through use of exotic accessions, 5) support for breeding region- or use-specific cultivars, and 6) collection of foreign agricultural information for breeding cultivars for overseas markets. Eventually the responsible group for the final development of commercial cultivars, production, sales and management is private companies. Therefore, private companies also should have to do their best to develop competitive cultivars with a missionary spirit and endeavor for both domestic and overseas markets in cooperation with public institutions. Management based on competition, professionalism and rationalism is also urged. We are going to conclude with optimism that we can make a new vault of progress once the private and public sectors closely cooperate for the development of Korean horticultural seed industry by overcoming this crisis.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.564-567
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• 2011

A new standard rose cultivar 'Pink Bell' was bred from a cross between pink standard cultivar 'Sweet Pink' and pink standard cultivar '"Pink Pearl' at the National Institute of Horticultural & Herbal Science. A cross was made in 2003 and 'Pink Bell' was finally selected in 2008 after investigating its characteristics for three years from 2006 to 2008 (UPOV standards). 'Pink Bell', a pink color standard cultivar grows vigorously and has a high yield. The major characteristics of this cultivar are $162stems/m^2/year$ in yield, 69.8 cm in length of cut flower, 10.4 cm in flower diameter, 44.5 in petal number per stem, and 12.0 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar was relatively higher than that of control cultivar, 'Nobless'.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.103-108
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• 2004

This study was carried out to develop the efficient methods for the subsequent progeny of intersectional hybrid between Oriental and Asiatic lily hybrids. The pollen fertility and germination ability of 3 different allotetraploids (OAOA) after somatic chromosome doubling was ranged from 0 to 80 percent on artificial pollen germination medium. The number of BC$_1$ progeny using allotetraploid of F$_1$ OA-hybrid as male and female parent was different. The efficiency of BC$_1$ progeny production was increased when F$_1$OA-hybrids was used as male rather than as female parent. And in back crosses of F$_1$ OA-hybrids with the Asiatic and Oriental hybrids, Asiatic hybrids showed higher efficiency on BC$_1$ progeny production. The ploidy level between 2x or 4x Asiatic hybrid and allotetraploid F$_1$ OA-hybrid was determined and showed higher progeny production in 2x-4x crosses rather than 4x-4x.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.2
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• pp.111-121
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• 1985

The present study was carried out to obtain some basic informations of the breeding of tobacco varieties. Genetically divergent 8 varieties, 3 flue-cured, 2 burley and 3 sun-cured tobaccos, were used in half diallel cross. In order to analyze the heterosis, combining abilities, modes of inheritance and correlations for some agronomic and chemical characters, 8 parents and 28 $F_2$ were tested. The results obtained were summarized as follows: The percentages of heterosis for yield, stem diameter, internode length and total sugar content in $F_2$ hybrid were positive , where-as those for the other characters were negative. Yield had significant positive genotypic and phenotypic correlations with plant height, days to flower, leaves per plant, leaf length, leaf width and leaf shape index (Leaf length/leaf width). General (GCA) and specific combining abilities (SCA) for all characters of $F_2$ hybrid were significant. In the effect of GCA, yield was greater in combinations of Bulgaria and Xanthi, days to flower and leaves per plant were those of Burley 21 and Va 528, leaf length and width were those of Coker 139, respectively. In the effect of SCA, the major part of characters were greater than those of others in the combinations of Burley 21, Va 528, Hicks.

• The Korean Journal of Zoology
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• v.31 no.1
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• pp.1-10
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• 1988

A syrnpatnc sample of Rana nigrnmaculata sand R plancyi (Anura) from Kwangu, Korea was investigated to clarify their taxonornic status and to estimate the degree of genic variation, genetic relatedness, and reproductive isolation between them, based on electrophoretic analysis, marphometric data, mating call, mating season, and habitat. All the characters measured including morphometric, genetic, behavioral, and ecological suggest that they are distinct species and R nigrnmaculata might have originated from R plancyi (tropical form about three and a half million years ago. An adult female was found to be Fl hybrid between two species The hybrid female possessed fettile eggs and morphologically intermediate to the parental species in head parts, hind limb, and web characters. The differences in mating call, mating behavior, breeding season, and habitat strongly suggest that postmating isolating mechanism is operating, even though very rare hybrid is found.

• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.382-388
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• 1988

Improvement of productivity by forest tree breeding work in Korea was estimated for a few important tree species. Progenies of 17 plus trees of red pine (Pines densiflora) outgrew by 57 percentage compared with progenies of unselected trees at age 15. If best three families are selected among the 17, more than double in volume grow-th is expected. The hybrid Pinus rigida ${\times}$ P. taeda showed more than double volume growth compare to P. rigida at a southern plantation at age 15. However, the superiority of the hybrid decreased at northern plantations, mainly because of low coldhardiness of the hybrid. At a northern plantation, the hybrid grew less than the P. rigida on upper hill, while the hybrid grew much better than the P. rigida on flat area. Another hybrid Populus alba ${\times}$ P. glandulosa grew faster than both parents by two to two and half times according to planting sites at age 10. Introduction of Pinus rigida also showed increased volume growth. Volume increase by selection of best five provenances among 45 at age 12 was estimated as 53 percent compare to progenies of plus trees in Korea, Additional 19 percent of volume increase was expected by selection of the best families within the best provenances. Annual production of chestnuts reached about 70,000 M/T by planting resistant clones to chestnut gall wasp (Dryocosmus kuriphilus), which killed almost all susceptible trees. Although polyploid trees and mutants have been produced by colchicine treatments in over 10 tree species, none of them is economically important Remarkable improvement of productivity is expected by biotechnology in future through selection, hybridization, introduction of foreign genes at cell, cell organelle and gene level, and gene transformation. At present, mass propagation of superior planting materials by tissue culture will increase the productivity.

• Korean Journal of Agricultural Science
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• v.33 no.1
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• pp.67-72
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• 2006

This study was carried out to compare a yield performance about CNU maize hybrids developed at the Maize Genetics and Breeding Lab. in Chungnam National University. Among the hybrids incorporated in the test, CNU 3 and 1 showed higher dry matter per 10a and lower kernel yield per 10a than check hybrid, Kwanganok. Hongchon 5 and Suwon169 showed higher kernel yield than Kwanganok. The average yield of CNU 3 hybrid in dry matter and CNU 4 in kernel yield were 2,106kg/10a and 854kg/10a in regional adaptability test, which were increased 33% and 8% compared with a check hybrid, respectively. Also, these hybrids had better stay green characteristics than check hybrid and showed moderately resistance to corn borer and leaf spot.

• Fisheries and Aquatic Sciences
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• v.21 no.5
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• pp.11.1-11.8
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• 2018

Interspecific hybridization experiments were conducted between the common seahorse Hippocampus kuda (male) and the slender seahorse H. reidi (female) during artificial rearing to develop a new aquarium fish with unique polyandrous mating. Molecular analysis via mitochondrial DNA (mtDNA) cytochrome b and nuclear DNA (ncDNA) ribosomal protein S7 gene supported the hybridization between the two species, and the hybrid also showed morphological characteristics of both species. Juveniles of H. kuda have dense melanophores on the whole body or only on the trunk and tail, whereas juveniles of H. reidi have thin melanophores on the whole body or present in stripes only along their prominent trunk and tail rings. However, all the hybrid juveniles had dense melanophores only on the tail, with the striped trunk rings, thus showing an intermediate pattern, and these patterns were limited to the fairly early stage of development (1-10 days old). In contrast, the two eye spines in the hybrid were apparent after 9 days old, which were not inherited from H. kuda (one eye spine), but from H. reidi (two eye spines). According to LOESS (local regression) analysis, the growth rate increased between 20 and 25 days, and the hybrids grew faster than H. kuda when they entered the explosive second phase of growth between 25 and 45 days for all the seahorses. This study highlights the hybridization between H. kuda and H. reidi may contribute to the improved taxonomic information of young seahorses.

• Journal of Sericultural and Entomological Science
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• v.48 no.2
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• pp.61-67
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• 2006

We investigated fertilization rate, hatchability rate, pupation rate and cocoon quality etc to selecting good characteristics of the wild silkmoth, Antheraea yamamai using method of indoor-and outdoor-rearing. As results of indoor rearing, the healthiness of A. yamamai was better in light green colour strain than that of dark green colour strain, but cocoon quality was better in dark green colour strain. There was a little effect to selecting major characteristics in grade of A, B and C strain classified with cocoon weight. $F_1$ hybrid was lower in fertilization rate and hatchability rate than parent, but higher in pupation rate and cocoon quality. There was no effect of heterosis in $F_2$ hybrid. In case of outdoor rearing, mortality rate was lower than that of indoor rearing but missing larva was higher. In addition, outdoor rearing is higher that indoor rearing in cocoon weight, cocoon shell weight and cocoon shell rate.