• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.71-77
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• 2012

The objective of this study is to develop the gene based sequence tagged site (STS) markers in wheat. The euchromatin enriched genomic library was constructed and the STS primer sets were designed using gene based DNA sequence. The euchromatin enriched genomic (EEG) DNA library in wheat was constructed using the $Mcr$A and $Mcr$BC system in $DH5{\alpha}$ cell. The 2,166 EEG colonies have been constructed by methylated DNA exclusion. Among the colonies, 606 colonies with the size between 400 and 1200 bp of PCR products were selected for sequencing. In order to develop the gene based STS primers, blast analysis comparing between wheat genetic information and rice genome sequence was employed. The 227 STS primers mainly matched on $Triticum$ $aestivum$ (hexaploid), $Triticum$ $turgidum$ (tetraploid), $Aegilops$ (diploid), and other plants. The polymorphisms were detected in PCR products after digestion with restriction enzymes. The eight STS markers that showed 32 polymorphisms in twelve wheat genotypes were developed using 227 STS primers. The STS primers analysis will be useful for generation of informative molecular markers in wheat. Development of gene based STS marker is to identify the genetic function through cloning of target gene and find the new allele of target trait.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.113-116
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• 2001

Chromosomal variation was investigated in the female and male somaclones regenerated from the leaf segment culture of Rumex acetosa L. Difference in phenotype depending on the sexuality was not observed. In female somaclones, 21 among 25 somaclones carried the same chromosome complements (2n＝14) with wildtype and others were tetraploids (2n=28), Considerable chromosomal variation was found in male somaclones. Only 4 among 20 somaclones carried normal chromosome number (2n=15) and 13 somaclones were aneuploids.

• Korean Journal of Plant Taxonomy
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• v.51 no.1
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• pp.1-9
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• 2021

Symplocarpus koreanus (Araceae; Orontioideae) from Korea is described as new. Symplocarpus koreanus has long been considered to be conspecific with S. renifolius in Japan, but phylogenetic, morphological, and cytological data indicate its taxonomic distinction. Compared to S. renifolius, S. koreanus has a much smaller spathe and more spherical spadix with fewer, smaller flowers. Previous phylogenetic studies also suggested that S. koreanus is more closely related to nonthermogenic S. nipponicus than to S. renifolius in Japan. Like its nonthermogenic sister species, S. nipponicus, in Korea and Japan, S. koreanus is diploid (2n = 2x = 30), while S. renifolius in Japan is tetraploid (2n = 4x = 60). A detailed species description, geographical distribution, major morphological differences between the species and a dichotomous key to the species in eastern Asia are provided.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.365-371
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• 2023

This experiment was carried out to breed a medium maturing variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, Rural Development Administration (RDA), Cheonan from 2019 to 2020. An Italian ryegrass variety, IR 604 is a tetraploid variety with green in leaf color and has half-erect growth habit in late autumn and erect growth habit in early spring, IR 604 was on May 17 in heading date as a medium maturing variety. Also, IR 604 was longer by 11 cm in flag leaf length and longer by 1.3 cm in plant height than those of the control variety, Kowinner, respectively. IR 604 was also thicker by 1.0 mm in stem thickness and strong in winter hardness. Dry matter (DM) yield (11,036 kg/ha) of IR 604 was 16.6% higher than that of Kowinner. Total digestible nutrient (TDN), crude protein (CP) and relative feed value (RFV) of IR 604 were 60.4, 13.8% and 100.6 which are 1.4, 3.3%, 7.7 higher than those of Kowinner, respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) of IR 604 were 35.5 and 56.7% which are 1.3 and 3.6% lower than those of Kowinner, respectively.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.761-770
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• 2016

This study investigated the variation in fruit characteristics between different triploid progenies derived from a cross between tetraploid and diploid grape cultivars, with the aim of developing high quality, labor-saving triploid grapes. No differences were found in fruit quality traits such as soluble solids content and titratable acidity, whereas significant variation was noted in cluster weight induced by a one-time application of GA3 (100 ppm) on the triploid progeny of different cross combinations. The cluster weight was higher in progeny obtained from 'Kyoho' ${\times}$ 'Sekirei' than for offspring derived from other cross combinations; deviation in the mean cluster weight was also small for 'Kyoho' ${\times}$ 'Sekirei' progeny. These results suggest that specific cross combinations, such as 'Kyoho' ${\times}$ 'Sekirei', can be used to efficiently breed new, labor-saving seedless grape cultivars.

• Reproductive and Developmental Biology
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• v.33 no.2
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• pp.93-98
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• 2009

In this study, bovine Dnmt1 cDNA was sequenced and detected Dnmt1 mRNA level in bovine tissues by northern blot, methylation pattern of genome by southern blot, specific localization of Dnmt1 in mouse and bovine preimplantation embryos by immunocytostaining and Dnmt1 protein level in ovary and testis by western blot. Bovine Dnmt1 cDNA sequence showed more homology with that of human than mouse and rat. The RNA level of Dnmt1 was 10 times higher expression in placenta than other tissues. This indicates that placenta was hypermethylated compared to others organs. The genomic DNA could not be cut by a specific restriction enzyme (HpaII) in placenta, lung and liver of bovine. It suggests that Dnmt1 in some somatic cells was already methylated. Dnmt1, which has the antibody epitope 1316~1616, was distributed in nucleus and cytoplasm including the stage of pronuclear stage and maturation of oocyte and gradually weaken to blastocyst stage compare to negative. In addition, Dnmt1 was strongly expressed in tetraploid embryo and cloned 8-cell than IVF 8-cell. An aberrant pattern of DNA methylation in cloned embryo may be abnormal development of fetus, embryonic lethality and placenta dysfunction. The somatic specific band (190kDa) was appeared in ovary and testis, but oocyte specific band (175kDa) was not. Further investigations are necessary to understand the complex links between the methyltransferases and the transcriptional activity of genes in the cloned bovine tissues.

• Journal of Sericultural and Entomological Science
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• v.46 no.1
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• pp.12-17
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• 2004

New triploid mulberry cultivar, Suilppong was bred among selected lines from F$_1$ seedlings obtained by crossing the female, artificial tetraploid No. 411 which obtained from Chungilppong seedlings, and the male, Kugsang 21. Local adaptability test has been carried out at four places (Suwon, Kongju, Jeonju and Jangsung) for five years since 1997. Leaf quality was tested by silkworm rearing for two silkworm rearing seasons (spring and autumn) at Suwon in 2000. Suilppong was recognized to be superior in productivity to control cultivar, Kaeryangppong. The new cultivar, Suilppong, has following agronomic characteristics as compared with Kaeryangnppong, which is leading cultivar widely cultivating in Korea. It is belonging to Morus alba L. with mixed shapes from the ovate to 5 lobated leaf shape, sprouting in spring nearly the same to the Kaeryangppong (Morus alba L.), high leaf yielding of 20% compared to Kaeryangppong (Morus alba L.). It is adaptable to everywhere except the places where cold damage occurs frequently in Korea. Suilppong is recommended to rear silkworms not only in spring but also in autumn besides for young silkworms.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.320-326
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• 2009

The carbon dioxide concentration of the atmosphere is projected to increase by almost 50% over the first 50 years of this century. The major cause of this increase is continued combustion of fossil fuels. As a result, the significant changes in climate that have already occurred will be amplified, in particular a global temperature increase. Renewable energy production has a central role to play in abating net $CO_2$ emissions to a level that will arrest the development of global warming. Especially, biomass crops are becoming increasingly important as concerns grow about climate change and the need to replace carbon dioxideproducing fossil fuels with carbon-neutral renewable sources of energy. To succeed in this role, biomass crop has to grow rapidly and yield a reliable, regular harvest. A prime candidate is Miscanthus, or Asian elephant grass, a perennial species that produces over 3 metres of bamboo-like stems in a year. Miscanthus species are typically diploid or tetraploid. Hybrids between species with different ploidy levels result in the highly productive triploid hybrids, M. ${\times}$ giganteus. Here we will detail the Miscanthus characteristics desired of a biomass fuel crop.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.1-10
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• 1997

Unreduced (2n) gametes are meiotic products (pollen or egg) having a sporophytic (somatic) chromosome number, resulting from abnormalities during either microsporogenesis or megasporogenesis. They occur naturally at a low frequency in many plant species. Unreduced (2n) gametes in plants can be identified for four possible ways as follow i) pollen size and/or shape differences between haploid (n) and diploid (2n) pollen, ii) ploidy analysis (chromosome number) of progeny or meiotic analysis (presence of dyads andlor triads at the microspore stage), iii) progeny performance and fertility and iv) dosage of isozyme and DNA markers. Unreduced (2n) gametes can be an effective breeding tool in synthesizing new cultivars, providing a unique method to maximizing heterozygosity, i.e., transferring a large proportion of the non-additive genetic effects (intra- and inter- locus interactions) h m parent to offspring and can also be used to overcome infertility of interploidy crosses. Sexual polyploidization through 2n gametes has been a major route to the formation of naturally occurring polyploids. The three mechanisms of 2n pollen formation in potato have been discovered as follow: i) parallel spindles (ps) or tripolar spindles (ts), ii) premature cytokinesis (pc-I, pc-2) and iii) synaptic mutants (sy-2, sy-3, sy-4). Genetic analysis indicated that the mechanisms of 2n gamete formation were controlled by single recessive gene in potato, alfalfa, red clover, etc., and by two recessive genes in wheat. The use of 2n gametes which can efficiently transfer germplasm fiom wild relatives to cultivated species, especially fiom diploid to tetraploid could make a contribution to the improvement of germplasm base in breeding programs.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.1-6
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• 2000

Improvement of cold-tolerance of Italian ryegrass(Lo1ium multiflorum L.) is an important breeding objectivefor enlargement of cultivation area in Korea. To develop the cold-tolerant variety of Italian ryegrass,cold-tolerant clones survived under - 13- - 14$^{\circ}$C of minimum average air temperature in January wereselected in the area of Dun Nae, Kwangwon Province. The 5 lines of Italian ryegrass clones selected werepolycrossed for seed production. Synthetic seeds were examined on growth characters and forage productionsin Suwon from 1996 to 1998, in Unbong 1997 and in Younchun 1998, respectively. The growth charactersand forage productions of Italian ryegrass variety named as "Hwasan 101" were summarized as follow ;ltalian ryegrass variety, Hwasan 101 was tetraploid and showed semi-prostrate growth habit in autumn andwas not only dark green in leaf color and broad in flag leaf width but also excellent in leafiness. Also, itshowed low plant height at first heading date of 20th May and excellent lodging tolerance. Expecially,Hwasan 101 in all trial regions was 80 -90% of winter survivals that was higher than 60 -90% of Florida80 and Marshall varieties. Therefore we estimate that Hwasan 101 can be cultivated in regions that is higherthan -9$^{\circ}$C in minimum average air temperature and lower than 400m in sea level. In forage production ofHwasan 101, fresh weight and total digestible nutrient(TDN) yield were 66,940 and 6,551kghq and drymatter yield was 10,050kgha. In conclusion, Italian ryegrass, Hwasan 101 was medium and late maturingvariety but excellent in cold-tolerance, lodging-tolerance, leafiness, and forage production.(Key words : Italian ryegrass, Cold tolerance, New variety)ian ryegrass, Cold tolerance, New variety)