• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.100-104
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• 1997

A new baekji(Angelica dahurica Bentham et Hooker) variety, Baekji l, was developed through a pure line selection at the Gyeongbug Provincial RDA during the period of 1990 to 1995. The variety was characterized to have high plant height. Long root length and large root diameter as compared with a check varicty of Bonghwa baekji but emergence date, flowering date and leaf number of Baekji l was similar to that of the check variety, and it was also more tolerant to nematode and heat stress. Peeled root color of Backji l was yellowbrown but number of the lateral root of the variety was greater. The dried-root yield of Baekji l in yield trial, regional adaptation trial and farmer's field trial was always $21\sim31%$ higher than that of the check variety.

• 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).

• Journal of Korean Society of Forest Science
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• v.42 no.1
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• pp.74-82
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• 1979

Pinus densiflora S. et Z. which has the widest distribution and highest stock at present in Korea and has used as materials for fuel, house construction, furniture and many other purposes for several hundred years, is considered as one of major species of economic importance, although there are a few epidemic insect injuries and silvicultural difficulties in regeneration. However, since disorderly cutting has been conducted for long time, the valuable local stands have disappeared. Therefore immediate attempts should be taken on the gene conservation and genetic studies including heritabilities and genetic gains of desirable characters. One hundred and twently five plus trees have so far been selected from the nationwide area and kept for the purpose of seed orchard establishment and other theoretical studies. In this study, the wind pollinated seeds of grafted stocks of 13 plus trees in clone bank located in Suweon and the seeds of 4 Japanese plus trees were collected and their progenies were used for heritability study. As indicated in figure 1, thirteen plus trees are from the middle part of Korea and two experimental plantations were laid out in ]972 (1-1 stock) by the randomized block design with five replications, consisting of 10 trees line plots of each family in each replication. Tree height, root collar diameter and branch diameter at 1cm apart from the main stem were measured. The results are summarized as follows 1. The rank of height growth of each plus tree progenies by age was greatly changed under age 3 and it was affected more in poor site than good site. 2. The heritabilities of height growth were estimated to be 7.2% at age 3, negative sign at age 4, 9.4% at age 5, 13.0% at age 6, 8.1% at age 7 and abrupt increase of 63.8% at age 8. The heritabilities were generally increased with increase of age. 3. The heritabilities of root collar diameter and branch diameter (average of the three biggest branches) was 3.2% and 11.8% at age 8 respectively. 4. The genetic gain was largest at age 8 and it was 46.6% when a selection intensity, 1/500 was taken. It, therefore, seems to be reasonable that selection should not be made under age 7.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.53-61
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• 1986

The races of soybean cyst nematode, Heterodera glycines were investigated at 13 localities in Kyungpook, Chungpook and Cheonnam provinces for the resistant soybean variety selection to soybean cyst nematode. Race C, 1, and 5 were distributed and among them race 5 was dominant in Korea. Native soybean 203 lines and 25 introduced soybean varieties were investigated in field where soybean cyst nematode race 5 infested. As the result, the reproduction of soybean cyst nematode in native soybean lines decreased on entry number 18, 21, 36, 38, 41, 42, 43, 45, 55, 59, 68, 72, 75, 93, 94, 95, 98, 123, 131, 136, 146, 170, 174, 187, 190, 191 than others. And then, in pot experiment, entry number 170 showed moderately resistant with 10 cysts per root, while entry number 55 was decreased reproduction a little and the other 25 line appeared susceptibility. In introduced soybean varieties, Peking, Illsoy and PI90763 showed resistance and not reproduction in field and pot experiment. But Custer, Delmar, Dyer and Jackson represented moderately resistant under 10 cysts, while the other 18 varieties were susceptible. In yield analysis, native soybean line 170 showed the same tendency as Peking and PI90763 known for resistant varieties in decreased rate of branch number, pod number, pod weight per plant and weight of 100 grains. Peking and PI90763 decreased at the rate of under 1.6% in branch number, pod number, pod weight per plant and weight of 100 grains, while Illsoy showed a little higher decreased rate of 3.8% in pod number and 3.4% in pod weight per plant. Custer, Delmar, Dyer and Jackson represented a little higher decreased rate in yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.214-221
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• 2020

Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary to develop crops with increased salt tolerance for cultivation in saline soils such as is found in reclaimed land. The objective of this study was to develop a salt-tolerant silage rice line that grows on reclaimed land. In order to develop this salt-tolerant silage rice, we transferred Saltol, a major QTL associated with salt tolerance, from IR64-Saltol, a salt-tolerant indica variety, into Mogyang, a susceptible elite japonica variety. To determine the effect of salt stress, Mogyang and IR64-Saltol cultivars were grown on a medium containing various concentrations of NaCl in in vitro conditions. Shoot length was found to decrease with increasing salt concentrations, and root growth was almost arrested at NaCl concentrations over 50 mM in the Mogyang cultivar. Based on these preliminary results, we screened five salt-tolerant lines showing superior growth under salt stress conditions. Polymerase chain reaction and sequencing results showed that the introgression types of Saltol QTL were derived from the IR64-Saltol cultivar in almost all selected lines. Based on the observed growth and physiological characteristics, the new Saltol introgression lines showed higher salt tolerance compared to the Mogyang parental cultivar. The salt-tolerant lines identified in this study could be used as a genetic resource to improve rice salt tolerance.