• Research in Plant Disease
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• v.21 no.2
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• pp.99-102
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• 2015

Cucumber mosaic virus (CMV) is one of the most destructive viruses in chilli pepper. An isolate of CMV was obtained from the chilli pepper cv. Chungyang showing top necrosis symptom in 2013 and designated as CMV-GTN. CMV-GTN was compared with the well-characterized isolate, CMV-Ca-P1, by investigating their amino acid sequences of the coat protein (CP) and biological reactions in several host plants. The CP of CMV-Ca-P1 composed of 217 amino acids but that of CMV-GTN composed of 218 amino acids by including additional valine in the $57^{th}$ amino acid position. Amino acid sequence similarity of the CP gene among CMV-GTN and other CMV isolates recorded in the GeneBank database ranged from 96% to 99%. CMV-GTN was selected as a representative isolate to screen the resistance pepper cultivars to CMV because it was highly pathogenic to tomatoes and peppers upon biological assays. The virulence of CMV-GTN was tested on 135 pepper cultivars which has been bred in Korea and compared with that of CMV-Ca-P1. Only the cv. Premium was resistant and three cvs. Hot star, Kaiser, and Good choice were moderately resistant to CMV-GTN, whereas two cvs. Baerotta and Kaiser were resistant to CMV-Ca-P1.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.568-573
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• 2009

A new soybean variety, "Singang", was released by NICS, RDA in 2008. It is resistant to soybean mosic virus (SMV), which is one of the most serious diseases in soybean production. "Singang" had been developed for seven years by molecular marker-assisted selection (MAS) breeding method using recurrent parent, "Sowon", and donor parent, "L29" which has the SMV-resistance gene, Rsv3. Selected promising breeding line, Suwon 242, was evaluated in yield trials for 2 years from 2005 to 2006 at NICS. Regional yield trials were performed for 3 years from 2006 to 2008 in five locations including Jeju. Agronomic characteristics of "Singang" is a determinate growth habit, purple flower color, grey pubescence, yellow testa, light brown hilum and lanceolate leaflet shape. "Singang" showed the similar performance to "Sowon" cultivar. This variety showed 3 days shorter in days to maturity than the check variety (Pungsannamul). The average yield under regional yield trials in five location was 2.78t/ha. It is adaptable to the whole country except for Gangwon province.

• 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 Environmental Biology
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• v.39 no.3
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• pp.329-335
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• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.269-269
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• 2022

Pre-harvest sprouting (PHS) on rice panicles is getting problematic in recent several years in Korea due to climate changes such as high temperature and more frequent typhoons during harvesting season. PHS negatively affects grain quality severely and also yield. Genetic improvement of Korean varieties (Oryza sativa ssp. japonica) through a marker assisted-backcross breeding (MAB) with the known PHS resistant genes must be one of ideal solutions. However, the final breeding products of MAB occasionally exhibit unwanted traits, especially the cross between genetically distant parents. This might be caused by linkage drag and/or presence of the gene-unlinked donor introgressions, resulting that the final products could not be released to the farmers. The major PHS resistance gene, Sdr4 (Seed dormancy 4) originated from an indica cultivar, Kasalath was selected as a donor gene. In order to avoid unexpected phenotypes in the breeding products, we performed a precision marker-based breeding (PMBB) consisting of foreground, recombinant, and background selections (FS, RS, and BS) which aim to develop 'single small introgression lines' (~100 kb introgression). Korean varieties (Ilpum and Gopum) were crossed with Kasalath. We developed Sdr4-allele specific markers for FS and a set of polymorphic flanking markers near the Sdr4 (-350kb and +420kb) for RS. To minimize linkage drag, the small introgression (< 125kb) containing Sdr4 was selected in Ilpum background (BC₂F₄) through 1^st RS with ~1,200 F₂ or BC₁F₂ plants (one side trimmed) and then 2^nd RS with ~1,000 progenies from the 1^st RS selected plants (another side trimmed). After RS, the selected lines were genotyped by using Infinium 7K SNP chip to detect other donor introgressions and the lines were backcrossed. Currently BS is on-going from the backcross-derived progenies with BS markers to remove residual introgressions. During the PMBB process, genetic effect of Sdr-4-Kasalath allele was confirmed in Ilpum and Gopum backgrounds by PHS phenotyping using the segregating BC₂F₃ or BC₁F₄ materials. The Sdr4 PMBB lines in Ilpum background (< 125kb introgression) will be valuable genetic resources to improve PHS resistance in modem popular temperate japonica varieties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.280-286
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• 2016

This study was conducted to evaluate the growth characteristics and dry matter yields of Italian ryegrass (Lolium multiflorum Lam., IRG) cultivars for three years (2011~2013). The cold-resistance of domestic cultivars was stronger than other foreign varieties. Among early-maturing cultivars, dry matter (DM) yield of 'Kowinearly' was significantly higher (8,751 kg/ha) than other cultivars (p<0.05). In medium-maturing cultivars, DM yield of 'Kowinmaster' and 'Tam 90' was 9,394 and 7,461 kg/ha, respectively. Of the two, the former's DM yield was higher than the latter's (p<0.05). Among late-maturing cultivars, DM yield of 'Hwasan 104' (9,809 kg/ha) was similar to 'Hwasan 101' (9,354 kg/ha), but significantly higher than the other late-maturing cultivars (p<0.05). According to the results obtained from present study, early-maturing cultivars with cold-tolerance and high productivity is required for the paddy field cultivation of an Italian ryegrass cultivar after rice harvest in Cheonan region. Medium- and late-maturing cultivars are more advantageous for the dry field cultivation of the maximum quantity that is possible. In conclusion, to select which cultivar/s to grow, the climate of the growing area, weather conditions, and the cropping system must all be considered.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.455-463
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• 1996

Studies were carried out to determine the effect of sulfur dioxide on leaf injury and yield of ten soybean cultivars. Plants were fumigated with 2.0 ppm of $SO_2$ for 4 or 8 h in a closed-top field chamber. In the comparison of foliar injury, Paldalkong and Eunhakong were more susceptible to $SO_2$ than Bogwangkong, Jangsukong, and Jangkeungkong. Correlations between chlorophyll contents, peroxidase activity, and stomatal resistance of leaves and foliar susceptibility were insignificant. However, significant correlations $(r=-0.611^{\ast})$ were found between superoxide dismutase activity and foliar injury rates. Dry weight, number of pods and total grains were significantly reduced by $SO_2$ fumigation but plant height, number of nods and weight of 100 grains were not affected. Yield reduction rates were higher in Eunhakong and Paldalkong than in Bogwangkong and Jangkeungkong. A liniar relationship was found between foliar injury rate and the percent crop loss with a significant coefficient of b=-1.17 in the susceptible cultivar of Paldalkong, but Bogwangkong, insusceptible cultivar, showed lower value of -0.165.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.617-624
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• 2002

Annual legume is being used as an important source of protein for farm animals and an ingredient for nitrogen fertilizers. There are, however, difficulties in selecting appropriate cultivar and forage management technique. The objective of this study is to select the best performing cultivars and evaluate a forage value on annual legume at two locations (Suwon and Sunghwan) for 1 year (1999${\sim}$2000). All cultivars shown a seedling vigor and lodging resistance of 8 rating or higher. Crimson and rose clover showed that they are appropriate for overwintering, but ;Laser; (35.9%) and 'Nitro'(9.1%) of persian clover variety did not overwinter well from 1999 to 2000. Flower stage was observed 4th of May for 'Tibbee', 6th of May for 'Contea' crimson clover, and 29th of April for 'Bolta balansa' rose clover. DM yield of a crimson clover 'Contea' (4,218kg/ha) was the highest among the legume forage. A crimson clover 'Tibbee' and rose clover 'Bolta balansa' also had a high production yield (3,874 and 3,828kg/ha). Calculations of relative feed value (RFV) based on the acid and neutral detergent fiber (ADF and NDF) of annual legume were over 125, which means that quality was high. According to the results of this study, crimson and rose clovers are recommended due to their high winter survival rate and high DM yield. Persian clover is not recommended because of a low overwintering rate at the Central region in Korea.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.55-59
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• 2007

The study was carried out to develop transformants resisting to Phyophthora blight disease in the domestic pepper cultivar Subicho. In transforming of syn600 promoter with elicitin gene using Agrobacterium (LBA4404/pBI101 syn600-syn${\alpha}$-elicitin) to cotyledons of pepper, rate of shoot formation in 'Subicho' was 11.1% in medium containing 3 mg/L zeatin and 0.05 mg/L NAA, and also 12.8% in medium containing combination of 4 mg/L zeatin and 0.05 mg/L MAA. For PCR reaction using elicitin gene primer of transformants regenerated from cotyledons, we detected a specific band of 536 bp, and also showed strong signal at position of 536 bp in accordance with NPTII gene used as probe in Southern blot. Transformants pepper shown resistance to blight fungus was inoculated to seedlings of the $T_{1}\;and\;T_{2}$ transformants by concentration (density: zoo spore $10^{3}/mL$).

• The Korean Journal of Mycology
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• v.10 no.4
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• pp.181-185
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• 1982

Immature apple fruits of cultivars Fuji and Miller were completely resistant to Macrophoma sp. until 10 July. When inoculated on 31 July, apples became susceptible to this fungus, irrespective of cultivar. This fungus grew better on Fuji than Miller. Lesion enlargement on apple at $25^{\circ}C$ was remarkably pronounced relative to $20^{\circ}C$. In both cultivars, the amount of total soluble carbohydrates or reducing sugars in apple fruit flesh was gradually increased as apples became mature. The healthy apples of cultivar Fuji had a higher amount of carbohydrates than those of Miller. The infected apples contained more soluble carbohydrates in comparison to the healthy ones. In healthy apples, there were no consistent differences between Fuji and Miller in amount of total soluble amino acids. With increasing age of apples, the amount of soluble amino acids declined in the fruit flesh of both cultivars. Levels of carbohydrates and amino acids in apple fruits were discussed in association with the immature fruit resistance to Macrophoma sp.