• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.205-211
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• 2005

This study was carried out to construct cold-tolerance characteristics. The RILs were developed from progenies of a cross between cold-susceptible Tongil-type rice variety, Milyang 23 and cold-tolerant Japonica rice variety, Stejaree 45 by single seed descent methods. The 175 RILs $(F_8)$ were evaluated for cold tolerance traits by field screening under cold-water irrigation. Frequency distribution of RILs in leaf discoloration, heading delay, culm length reduction and number of spikelets reduction displayed nearly normal distributions with transgressive segregations to either side of parents, while the spikelet fertility reduction and panicle exsertion at low-temperature showed the more or less skewed continuous distribution toward the susceptible parent. Higher heritabilities over $60\%$ were observed in leaf discoloration, spikelet fertility reduction, panicle exsertion, while relatively lower heritabilities less than $40\%$ were observed in culm length reduction, number of spikelets reduction and grain yield reduction. Some cold-tolerance RILs were selected effectively by cold water irrigation, which are expected to be good materials in breeding program for cold tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.489-494
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• 1993

The amount of maize being imported from other countries to meet the national demand are increasing every year. Regardless of the usage whether it is for silage or for human consumption, amount of seeds for farmers are ever being increased. In order to solve the problems arising from the seed import, a program for developing waxy hybrids with high quality was set up at the College of Agr., Chungnam National University. The main breeding targets for high quality waxy hybrids are focused on the pericarp thickness. In order to obtain basic information needed for developing hybrids with thin pericarp, six inbred lines all derived from open pollinated Korean waxy lines were diallel crossed. Results obtained indicate that waxy hybrids with thin pericarp can be developed by choosing proper parental lines. Of the six inbreds, Jewon inbred had utmost thin pericarp compared with other lines. Hybrids crossed with Jewon showed also thinner pericarp than other hybrids. However, Danyang which has thick pericarp showed thicker pericarp in hybrid combinations. Variance due to general combining abilities was greater than the variance due to the specific combining abilities, indicating that additive gene effects are more important. The pericarp thickness of waxy hybrid endosperm varied with the parts of pericarp. The germinal side of the pericarp is comparatively thinner than the abgerminal side. The upper part (crown) has thicker pericaip than lower part (tip) of the kernel.

• Molecules and Cells
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• v.24 no.1
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• pp.83-94
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• 2007

During monocarpic senescence in higher plants, functional stay-green delays leaf yellowing, maintaining photosynthetic competence, whereas nonfunctional stay-green retains leaf greenness without sustaining photosynthetic activity. Thus, functional stay-green is considered a beneficial trait that can increase grain yield in cereal crops. A stay-green japonica rice 'SNU-SG1' had a good seed-setting rate and grain yield, indicating the presence of a functional stay-green genotype. SNU-SG1 was crossed with two regular cultivars to determine the inheritance mode and identify major QTLs conferring stay-green in SNU-SG1. For QTL analysis, linkage maps with 100 and 116 DNA marker loci were constructed using selective genotyping with $F_2$ and RIL (recombinant inbred line) populations, respectively. Molecular marker-based QTL analyses with both populations revealed that the functional stay-green phenotype of SNU-SG1 is regulated by several major QTLs accounting for a large portion of the genetic variation. Three main-effect QTLs located on chromosomes 7 and 9 were detected in both populations and a number of epistatic-effect QTLs were also found. The amount of variation explained by several digenic interactions was larger than that explained by main-effect QTLs. Two main-effect QTLs on chromosome 9 can be considered the target loci that most influence the functional stay-green in SNU-SG1. The functional stay-green QTLs may help develop low-input high-yielding rice cultivars by QTL-marker-assisted breeding with SNU-SG1.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.917-921
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• 2014

'Hei-G' is a new tomato cultivar originating from the cross of two inbred lines, the maternal plant TKUI-3 separated from 'Kame' in 2007, and the paternal plant AL-1 developed by pedigree breeding. The new cultivar was registered as 'Hei-G' named 'JTB026 (Jeonnam-2)' based on characteristics and yield trials carried out in the spring of 3 years, from 2010 to 2012. 'Hei-G' is an indeterminate type with strong plant vigor. The fruit is round and the ripening fruit is blackish red. The average fruit weight of 'Hei-G' is about 43.4 g, and its marketable yield is $4,944kg{\cdot}10a^{-1}$. The lycopene content of 'Hei-G' ($11.8mg{\cdot}100g^{-1}$) is higher than that of other tomatoes (e.g., cv. Rapido, 3.1 mg). In addition, 'Hei-G' is suitable for environment-friendly protected cultivation because of its resistance to powdery mildew.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.833-836
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• 2013

'Hei' is a new cultivar of red with black flesh; originated from the cross of two inbred lines, mother plant, TKUI separated from 'Kame' in 2007 and father plant, TLB separated from tomato collected in Europe by pedigree breeding method. 'Hei' was tested for specific character and productivity of lines of tomatoes in spring for 2 years, 2008 to 2009. This variety had resistance to powdery mildew. 'Hei' is an indeterminate type. The fruit shape is round and the skin color is blackish red. The average fruit weight of 'Hei' is about 127.9 g and marketable yield is $5,715kg{\cdot}10a^{-1}$. Lycopene contents of 'Hei' are about $18.5mg{\cdot}100g^{-1}$, high compared with other tomato ($3.1mg{\cdot}100g^{-1}$). 'Hei' is suitable for environment-friendly protected cultivation because of resistance to powdery mildew.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.695-698
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• 2010

The incidence of Anthracnose causing severe damage to the foliage and fruit in watermelon has increased in some major watermelon producing areas in Korea. To develop anthracnose resistant line, 'AU-Producer' having resistant gene to anthracnose was selected from germplasm and crossed with high quality line '920533'. Following the initial cross, backrossing and disease screening were performed to select resistant lines that produced high yields with excellent quality fruit. As a results of these procedure, a mid maturing watermelon line, 'Hangyeol' with resistance to anthracnose (Colletotrichum orbiculare) race 1 and 3 was developed at the National Institute of Horticultural and Herbal Science, Rural Development Administration (RDA). It has red flesh and commonly produces fruit with clear stripes on skin between 5.3 to 10.1 kg. Average soluble solid contents are ranged from 9.8 to 11.8$^{\circ}$Bx. The yield and quality of 'Hangyeol' is comparable to or better than those harvested from the popular commercial cultivars. The achievement of this experiment could contribute to provide the resistant parents in an anthracnose resistance breeding program in watermelon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.134-146
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• 2023

Phytophthora root rot (PRR) is a major soybean disease caused by an oomycete, Phytophthora sojae. PRR can be severe in poorly drained fields or wet soils. The disease management primarily relies on resistance genes called Rps (resistance to P. sojae). This study aimed to identify resistance loci associated with resistance to P. sojae isolate 40468 in Daepung × CheonAl recombinant inbred line (RIL) population. CheonAl is resistant to the isolate, while Daepung is generally susceptible. We genotyped the parents and RIL population via high-throughput single nucleotide polymorphism genotyping and constructed a set of genetic maps. The presence or absence of resistance to P. sojae was evaluated via hypocotyl inoculation technique, and phenotypic distribution fit to a ratio of 1:1 (R:S) (χ² = 0.57, p = 0.75), indicating single gene mediated inheritance. Single-marker association and the linkage analysis identified a highly significant genomic region of 55.9~56.4 megabase pairs on chromosome 18 that explained ~98% of phenotypic variance. Many previous studies have reported several Rps genes in this region, and also it contains nine genes that are annotated to code leucine-rich repeat or serine/threonine kinase within the approximate 500 kilobase pairs interval based on the reference genome database. CheonAl is the first domestic soybean genotype characterized for resistance against P. sojae isolate 40468. Therefore, CheonAl could be a valuable genetic source for breeding resistance to P. sojae.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.56-63
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• 2014

Using commercial radish varieties for processing, about 30% of radish was discarded due to the root shape and low purity. To raise the processing ability, we tried to develop a new variety producing H-shaped root. As another characteristic required in variety for processing is high purity, we tried to raise purity using simple sequence repeats (SSR) markers for testing seed purity in every segregating generation. To develop Male-sterile (MS) seeding parent, we crossed commercial variety of 'Gwan dong spring' and 'Gyeo ryong spring'. One elite inbred was selected as recurrent parent for the MS plant. The major horticultural traits of selected inbred line were disease resistance, late bolting, heat resistance and bright green root top color. To develop pollen parent, we crossed commercial variety of 'Tae sang king' and 'Seoul spring'. We used individual selection method to develop H-shaped hard root and disease resistant inbred. In each segregating generation, we selected one plant based on phenotype and the uniformity of selected plant was tested by SSR markers using self-pollinated seeds. In the first segregating generation, 64.6% of sib plants shared the same band in PCR amplification using ACMP-490 primer and 66.7% using cnu-316 primer. The uniformity of segregating generations using ACMP-490 and cnu-316 raised in second generation to 68.8%, 70.8%, respectively; in third generation to 93.8%, 100%; in fourth generation to 93.8%, 100%; in fifth generation to 95.8%, 100%; in sixth generation to 100%, 100%. A novel cross was made using selected MS parent and pollen parent. When we checker the horticultural traits using autumn cultivation, the novel cross variety produced H-shaped root comparing other commercial varieties and produced highly uniform radish. Thus we registered this novel cross variety as 'YR ORE' at 2013 (Registration No. 4550).

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.21-21
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• 2017

Severe lodging has recurrently occurred at strong typhoon's hitting in recent climate change. The identification of quantitative trait loci (QTLs) and their responsible genes associated with a strong culm and their pyramiding are important for developing high-yielding varieties with a superior lodging resistance. To identify QTLs for lodging resistance, the tropical japonica line, Chugoku 117 and the improved indica variety, Habataki were selected as the donor parent, as these had thick and strong culms compared with the temperate japonica varieties in Japan such as Koshihikari. By using chromosome segment substitution lines (CSSLs) in which chromosome segments from the japonica variety were replaced to them from Habataki, we identified the QTLs for strong culm on chrs. 1 and 6, which were designated as STRONG CULM1 (SCM1) and STRONG CULM2 (SCM2), respectively. By using recombinant inbred lines (BILs) derived from a cross between Chugoku 117 and Koshihikari and introgression lines, we also identified the other QTLs for strong culm on chrs. 3 and 2, which were designated as STRONG CULM3 (SCM3) and STRONG CULM4 (SCM4), respectively. Candidate region of SCM1 includes Gn1 related to grain number. SCM2 was identical to APO1, a gene related to the control of panicle branch number, and SCM3 was identical to FC1, a strigolactone signaling associated gene, by performing fine mapping and positional cloning of these genes. To evaluate the effects of SCM1~SCM4 on lodging resistance, the Koshihiakri near isogenic line (NIL) with the introgressed SCM1 or SCM2 locus of Habataki (NIL-SCM1, NIL-SCM2) and the another Koshihikari NIL with the introgeressed SCM3 or SCM4 locus of Chugoku 117 (NIL-SCM3, NIL-SCM4) were developed. Then, we developed the pyramiding lines with double or triple combinations derived from step-by-step crosses among NIL-SCM1 NIL-SCM4. Triple pyramiding lines (NIL-SCM1+2+3, ~ NIL-SCM1+3+4) showed the largest culm diameter and the highest culm strength among the combinations and increased spikelet number due to the pleiotropic effects of these genes. Pyramiding of strong culm genes resulted in much increased culm thickness, culm strength and spikelet number due to their additive effect. SCM1 mainly contributed to enhance their pyramiding effect. These results in this study suggest the importance of identifying the combinations of superior alleles of strong culm genes among natural variation and pyramiding these genes for improving high-yielding varieties with a superior lodging resistance.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.180-183
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• 2011

'Yeomyeong', a new welsh onion (Allium fistulosum L.) variety, is developed by the Bioenergy Crop Research Center, NICS, RDA in 2004. This variety, as interspecific $F_1$ hybrid, is developed by a cross between onion (Allium. cepa L.) and welsh onion (A. fistulosum L). The first cross was conducted in 2003 between MOS8, onion male sterile line and G2, welsh onion inbred line. Horticultural and yield characteristics of this hybrid $F_1$ line was investigated in greenhouse for 2 years from 2004 to 2005 with fall cropping cultivation. It has a single pseudostem plant type, anthocyanin-colored pseudostem, and male sterile umbel. It showed intermediate plant type of the maternal parents in overall plant characteristics. 'Yeomyeong' is fall sawing variety and has higher plant height and pseudostem length than that of check variety 'Gumjang'. The yield potential of this variety was about 130.1MT/ha in greenhouse in spring harvseting season. This variety would be adaptable to the fall sowing cultivation in green house.