• Journal of Korean Society of Forest Science
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• v.69 no.1
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• pp.19-27
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• 1985

Introgressive hybridization of Pinus densiflora in Korea was investigated by examining the position of resin ducts in 4,992 trees from 67 populations. Judging that P. densiflora has only external resin ducts, P. thunbergii only medial resin ducts, and any tree which has even one needle with external and medial resin ducts is hybrid, hybrids are found at all populations investigated. As variation in position of resin ducts was found among needles on a tree, the number of needles investigated from a tree affects judgment of the tree's hybridity. Therefore, hybridity seems to be judged by many traits rather than by the single trait, position of resin ducts. Seed production by artificial pollination between P. densiflora and P. thunbergii was very poor, i.e. one full seed from five female flowers or from two mature cones. This poor seed production, in addition to the low hybrid vigor, if any, seems to make the artificial pollination between the two species for mass-production of seeds for planting impractical.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.577-589
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• 2021

Soil seed bank community contributes to the long-term conservation of plant diversity and vegetation dynamics, and their decreasing diversity and density with soil depth provide critical perspectives (deterministic and stochastic) for understanding the community disassembly process. We analyzed changes in species composition and diversity and structuring patterns by soil layer (top and bottom), including surface vegetation, in Gwangneung Forest, a mature forest with a vegetation climate in the temperate central part of the Korean Peninsula. From two layers of soil collected with a vertical difference of 10 cm, 934 specimens of 27 families, 40 genera, 44 species, three varieties, and 47 taxa, germinated. Although species diversity and germination density decreased in most comparative characteristics, including growth type, there was no statistical significance due to large deviations. Within-group variability of species composition was similar in the upper and lower soils, as was the decline pattern in co-occurred species (ζ-diversity) and change in species retention probability. The structuring process of the community composition in the two soil layers was fitted with an exponential correlation rather than a power function, demonstrating the dominance of the stochastic process. The pattern in diversity and species turnover according to soil depth in Gwangneung Forest was discovered to be structured by stochastic random events, such as seed vertical movement rather than interaction with trait characteristics.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.391-403
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• 2018

Genome resequencing by next-generation sequencing technology can reveal numerous single nucleotide polymorphisms (SNPs) within a closely-related cultivar group, which would enable the development of sufficient SNP markers for mapping and the identification of useful genes present in the cultivar group. We analyzed genome sequence data from 13 Korean japonica rice varieties and discovered 740,566 SNPs. The SNPs were distributed at 100-kbp intervals throughout the rice genome, although the SNP density was uneven among the chromosomes. Of the 740,566 SNPs, 1,014 SNP sites were selected on the basis of polymorphism information content (PIC) value higher than 0.4 per 200-kbp interval, and 506 of these SNPs were converted to Kompetitive Allele-Specific PCR (KASP) markers. The 506 KASP markers were tested for genotyping with the 13 sequenced Korean japonica rice varieties, and polymorphisms were detected in 400 KASP markers (79.1%) which would be suitable for genetic analysis and molecular breeding. Additionally, a genetic map comprising 205 KASP markers was successfully constructed with 188 $F_2$ progenies derived from a cross between the varieties, Junam and Nampyeong. In a phylogenetic analysis with 81 KASP markers, 13 Korean japonica varieties showed close genetic relationships and were divided into three groups. More KASP markers are being developed and these markers will be utilized in gene mapping, quantitative trait locus (QTL) analysis, marker-assisted selection and other strategies relevant to crop improvement.

• Journal of Life Science
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• v.20 no.8
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• pp.1186-1192
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• 2010

Soybean [Glycine max(L.) Merr.] is an important crop, accounting for 48% of the world market in oil crops. Improvements in economic traits, such as quality and oil constituents, arethe most important objectives in soybean breeding. The objective of this study was to identify quantitative trait loci (QTLs) that control seed size and fatty acid contents in soybean. 115 $F_{2:10}$ recombinant inbred lines (RIL) developed from a cross of 'Keunolkong' and 'Iksan10' were used. Narrow-sense heritability estimates based on a plot mean on 100 seed weight, saturated fatty acid (palmitic acid + stearic acid), and oleic, linoleic, and linolenic acid content were 0.72, 0.60, 0.83, 0.77 and 0.81, respectively. The 100 seeds weight was related to seven QTLs located on chromosomes 1, 3, 8, 9, 16 and 17. Two independent QTLs for saturated fatty acid content were identified on chromosomes 17 and 19. Five independent QTLs for oleic acid content wereidentified on chromosomes7, 11, 14, 16 and 19. Five QTLs for linoleic acid content were located on chromosomes 2, 11, 14, 16 and 19. Three QTLs for linolenic acid content were located on chromosomes 8, 10 and 19. Oleic, linoleic, and linolenic acid had one major common QTL on chromosome 19. Thus, linoleic and linolenic acid content were identified as common QTLs.

• Journal of Mushroom
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• v.10 no.2
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• pp.49-56
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• 2012

Two strains which have good traits in quality and speedy growing were selected based on previous report(Ryu, 2007) to breed a new strain carrying the traits in it. KNR2322 carrying high quality and KNR2503 carrying a speedy growing trait were cultivated to harvest monokaryons. The monokaryotic mycelia were characterized in growth rate, color, and stability. Selfing of monokaryons from KNR2322 and crossing between KNR2322- and KNR2503-derived monokaryons were performed. Two parental lines, $KNR2322-4{\times}37-6{\times}12(B)$ showing thremmatological values in weight and quality, 68.5g and 6.5 and $KNR2322-30{\times}KNR2503-60(A)$ was harvested in 13.5 days after scraping old medium were selected. Crossing between A and B resulted in two high quality and speedy growing strain, A8B8 and A8B10. Their days for harvest after scraping, weight, and quality were 14.0 days, 88.8g and 92.7g, 7.0 and 7.1. Originality tests were conducted with genomic DNAs of A8B8 and Keuneutari 3ho(commercial strain) by DNA fingerprinting a confrontation culture. The results showed polymorphism and a inhibition line between them. It suggested that the new strain have originality from the commercial strain. A8B8 have been registered in Korea Seed and Variety Service with as "Saesongi 1ho".

• 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.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.40-45
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• 2020

Over 500 genetically modified organisms (GMOs) have been developed since 1996, of which nearly 44% have glufosinate herbicide-tolerant traits. Identification of specific markers that can be used to identify herbicide-tolerant traits is challenging as the DNA sequences of the gene(s) of a trait are highly variable depending on the origin of the gene(s), plant species, and developers. To develop specific PCR marker(s) for the detection of the glufosinate-tolerance trait, DNA sequences of several pat or bar genes were compared and a diverse combination of PCR primer sets were examined using certified reference materials or transgenic plants. Based on both the qualitative and quantitative PCR tests, a primer set specific for pat and non-specific for bar was developed. Additionally, a set of markers that can detect both pat and bar was developed, and the quantitative PCR data indicated that the primer pairs were sensitive enough to detect 0.1% of the mixed seed content rate.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.507-514
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• 2010

Peanut(Arachis hypogaea L.) is one of the major oilseed crops. The peanut oil consists of palmitic, oleic and linoleic acids, which are present at levels of 10%, 36-67% and 15-43%, respectively. High oleate mutant of peanut F435 contains 80% oleate and as little as 2% linoleate in seed oil. Previous study indicated that delta 12 fatty acid desaturase is a major enzyme controlling the oleate content in seeds of oilseed crops. F435 sequence alignment of their coding regions disclosed that an extra A(adenine) was inserted at the position +2,823 bp of delta 12 fatty acid desaturase gene. This study was to develop molecular marker (SNP marker) co-segregating with the high oleate trait. Chopyeong ${\times}$ F435 $F_2$ 41 population were investigated using molecular marker and fatty acid assay (NIR and gas chromatography). Finally, this marker segregates Chopyeong type 26 lines, heterotype 9 lines and F435 type 6 lines. These results in our study suggested that SNP marker conform fatty acid assay.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.442-446
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• 2003

The Gene action for eight quantitative characters related to the plant type was estimated using diallel cross among three different plant types of sesame (Sesamum indicum L.) in 2001. The parental varieties used for diallel cross were Ahnnam and Yangbaeck as indeterminate type, ksan22 as semi-determinate type, and dt-45 and Suwon131 as determinate type. In variance and covariance analysis (Wr-Vr) for eight characters the mean square of array except for capsule length, 1,000 seed weight were significant, which suggest that varieties involved in diallel set cross may have epitasis. Complete dominance was observed in the flowering periods, and ratio of matured grains while partial dominance was observed in the plant height, no. of capsules per plant, and no. of branch per plant. Broad sense heritability for flowering periods, plant height, no. of capsules per plant, and no. of branch per plant ranged from 0.91 to 0.99. Narrow sense heritability for flowering periods, capsule length, ratio of matured grain, 1,000 seed eight were 0.18 to 0.34, and plant height, no. of capsules per plant and no. of branch per plant were ranged 0.77 to 0.81.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.334-339
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• 1983

With the 91 lines of Italian millet collected throughout the whole country in Korea and the 238 varieties from several Asian countries, trial was carried out to elucidate its differentiation, dissemination and distribution, and the ethnobotanical relations to the adjacent area. Glutinous millets which consisted of 66% among the collected Korean lines were widely distributed throughout the whole country, but non-glutinous ones were mainly distributed in the mountainous regions and Jeju island. The variations in germinability at low temperature were recognized among lines, but seemed not to be closely related to their regional distribution. The collected lines with small grain size were distributed mainly in the mountainous regions of middle and northern part of Korea and larger ones in Jeonnam province and Jeju island. And some of them were larger in grain size as compared with that of Japanese and Republic of China varieties. Seed coat color of collected lines in Korea showed wide variations from yellow to gray, especially in Gyungbuk province. However, all lines from Chungnam, Jeonnam and Gyungnam province were yellow in seed coat color. All lines from Korean collection except two lines indicated negative(-) phenol reaction which is very similar to that of Japan and China, while these were quite different from the varieties of Republic of China, Philippines and India, of which 30-60% showed positive(+) phenol reaction. The pattern of the esterase isozyme m Korean lines was simillar to that of Japanese lines and this was quite different from that of Republic of China, Philippines and India. Variation of this trait was greater in Chinese and Korean lines.