• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.50.1-50
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• 2002

• Applied Biological Chemistry
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• v.47 no.2
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• pp.164-169
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• 2004

In the course of our screening for biocontrol agent (BCA) against Streptomyces scabiei and S. turgidiscabies causing potato scab using 5,000 actinomtcete isolates, 9 antagonistic strains were selected as BCA candidates through in vitro and in vivo assay. An antagonistic strain, A020645 was highly resistant to some pesticides and antibiotics such as dazomet and mancozeb and showed high control value in vivo. Two bioactive compounds (compound A, B) were purified by anion exchange chromatography, solid phase (ODS) extraction, TLC and reverse phase HPLC. Their chemical structures are now thought to be nucleoside derivative as determined by $^1H-NMR$ data analysis. Their full chemical structures would be elucidated through $^{13}C-NMR$, HMQC and HMBC analyses. Further studies will be focused on fitness in soil and formulation of the BCA candidates.

• Research in Plant Disease
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• v.11 no.1
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• pp.66-71
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• 2005

The effect of medium components such as wheat bran, rice bran, oat meal, and soybean meal as basic ingredients and KH2PO4, glucose, and molasses as additives on mass production and anti-potato common scab activ ity of a streptomycete A020645 strain as a biocontrol agent (BCA) candidate was investigated. Of basicingredients, oat meal was the best one for mass poduction and enhancement of anti-potato common scabactivity. The biomass production of the active strain was more enhanced when 0.1-0.01.% glucose or molassesas additive were added into the basic medium. These information may have important implications in applying for effective formulation of BCA.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.622-627
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• 2011

This study was designed to investigate the possible role of 10 green manure crop extracts in antimicrobial activity against potato common scab (Streptomyces scabiei). Ten green manure crops were extracted with hexane, ether, ethylacetate, methanol and water. The DPPH radical scavenging activity of ether, methanol and water was higher than those of hexane and ethylacetate fractions. The fractions of methanol, ethylacetate, ether and water showed antimicrobial activity against Streptomyces scabiei from the concentration of 0.25 mg/mL. Methanol fraction of Sorghum showed the highest antimicrobial activity against this microorganism. This result suggests the sorghum extract was the best as good green manure crop with antimicrobial activity against Streptomyces scabiei.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.43.1-43
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• 1999

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.51-55
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• 2009

Jayoung was bred within the potato breeding program of Highland Agriculture Research Center (HARC), National Institute of Crop Science. It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. Jayoung was evaluated as a clone number Daegwan 1-104 for the growth and tuber characteristics, yielding ability, and resistance to major potato diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as Jayoung and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. Jayoung has a oval shape, shallow eye depth, dark purple skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.3 MT/ha, and it showed the highest yield in spring cropping. Jayoung showed high resistance to both common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to late blight (Phytophthora infestans). The dry matter content of Jayoung was fairy high 20.3%, therefore it is suitable for both chip processing and table usage. Its anthocyanin content was the highest in autumn cropping as 43.7 mg/100 g fresh weight and its mean anthocyanin content was 4.7 times higher than that of Jasim.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.502-506
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• 2009

"Hongyoung" was bred within the potato breeding program of National Institute of Highland Agriculture (NIHA). It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. "Hongyoung" was evaluated as a clone number Daegwan 1-102 for the growth and tuber characteristics, yielding ability, and resistance to major diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as "Hongyoung" and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. "Hongyoung" has a round shape, shallow eye depth, red skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.4 MT/ha, and it showed the highest yield in spring cropping. "Hongyoung" showed high resistance to common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to both potato virus Y (PVY) and late blight (Phytophthora infestans). The dry matter content of "Hongyoung" was low to medium 17.7%, therefore it is suitable for table use. Its anthocyanin content was the highest in autumn cropping with 31.8 mg/100g fresh weight and it contained 3.6 times higher anthocyanin than the control, Jasim.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.61-67
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• 2009

"Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.

• Research in Plant Disease
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• v.18 no.2
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• pp.117-122
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• 2012

In 2006, the effect of soil pH adjustment on control of common scab of potato caused by Streptomyces spp. was evaluated in the field. Soil with an original pH 5.7 was treated with sulfur of 42 kg/10a and calcium hydroxide of 81.6 kg/10a and 184.5 kg/10a to adjust pH 5.0, 6.0 and 6.5, respectively. Additionally, the effect of gypsum (522 kg/10a) on soil pH and disease severity was examined. The soil pH of sulfur treatment plot was continuously declined from 5.13 at tuber initiation time to 5.01 at harvest. The disease severity of sulfur treatment plot was relatively low (22.8%) and the marketable yield of that was high (90.5%). By contrast, the soil pHs treated with calcium hydroxide (81.6 kg/10a and 184.5 kg/10a) were increased (pH 6.06 and 6.49, respectively) at harvest. In addition, calcium hydroxide treatment plots showed higher disease severities (51.0% and 61.1%), and lower marketable yields (55.7% and 37.0%). Meanwhile, the soil pH of gypsum treatment plot was not changed until harvest, and the disease severity and the marketable yield were not significantly different from those of control. The effect of crop rotation was also evaluated with four crops such as welsh onion, soybean, corn and Chinese cabbage. These crops were planted in the infested field from 2005 to 2007, and potatoes were planted in the same field in 2008. The disease severities of potatoes produced after rotations with welsh onion, soybean, corn and Chinese cabbage for 3 years were 13.1%, 16.7%, 28.9% and 30.2%, respectively. However, the disease severity of 73.1% was shown in continuous cropping of potato for 3 years. In addition, similar effects were exhibited in the marketable yield. These results demonstrate that the adjustment of soil pH and crop rotation might be very useful tools to control common scab of potato.

• Korean Journal of Plant Resources
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• v.22 no.6
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• pp.483-488
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• 2009

The main objective of this breeding program is to develop high yielding, disease resistance and good processing potato cultivar. 'Gui Valley' is a clonal selection resulting from a cross between 'ND2471-8' and 'Cona'. It has medium plant height and light green foliage. 'Gui Valley' has medium flowering habit and light pink flowers. 'Gui Valley' is a medium maturing potato cultivar and tubers are smooth, yellow skin, light yellow flesh, long-oval tuber shape, distinct red eyes with medium depth and medium dormancy. It has high level of tuber uniformity and good keeping quality. 'Gui Valley' demonstrates resistance to potato virus Y (PVY), soft rot, but moderately susceptible to late blight and common scab. It is also resistant to most of the internal and external physiological disorders particularly dehiscence, hollow heart and internal brown spot. The specific gravity of 'Gui Valley' is significantly higher (1.097) than that of 'Shepody' (1.078). 'Gui Valley' has suitable for processing mainly French fries and chips. This cultivar has high level of tuber uniformity and capable of yielding 37.6 $t{\cdot}ha^{-1}$, which is 18.2% higher than the control potato cultivar 'Shepody' under optimum agronomical practices.