• Horticultural Science & Technology
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• v.29 no.6
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• pp.610-616
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• 2011

Clubroot disease caused by Plasmodiophora brassicae, induces damage to cruciferous vegetables worldwide. For control of the disease, many CR (clubroot resistant) $F_1$ hybrid cultivars of Chinese cabbage have been bred and released in Korea. In this study, we determined the race of 10 field isolates of P. brassicae collected from ten regions in Korea using Williams' differential varieties and investigated the degree of resistance of 25 commercial CR cultivars of Chinese cabbage to the isolates. The clubroot pathogens were assigned into two (HS and YC), two (HN1 and HN2), two (DJ and SS) and four (GS, GN, JS, and PC) isolates for race 2, race 4, race 5, race 9, respectively. All CR cultivars showed similar response, resistant or susceptible, to each isolate and the P. brassicae isolates were divided into two groups. Among them, the DJ, GS, GN, HS, and JS isolates could not infect the CR cultivars. In contrast, the SS, HN1, HN2, PC, and YC isolates caused severe clubroot disease on the CR cultivars like susceptible cultivars. Even though they belong to the same race, the CR cultivars showed a different response to the pathogens. The results suggest that the breakdown of CR in Chinese cabbage has already occurred in cultivation areas of Korea and resistance source introduced in CR cultivars may be very limited. In addition, it is likely that resistance genes of Williams' differential varieties to P. brassicae are different from the gene of CR cultivars of Chinese cabbage used in the study.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.43-45
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• 2003

This study was carried out to investigate sprouting and cold hardiness during wintering and thawing Periods in 7-year-old mulberry(Morus) three varieties of Kaeryangppong, Shinilppong and Yongcheonppong. The killing points of the mulberry twigs were investigated using DTA(Differential Thermal Analysis). (omitted)

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.277-282
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• 1983

Number and percentage of diseased area of leaf blast lesions formed on different leaf location were mostly distributed from the flag leaf(n-1) to the 3rd leaf from the top(n-3) in Tongil line rice varieties and on the 2nd leaf from the top(n-2) in Japonica type rice varieties. Especially leaf lesions of Nopung which was more susceptible to leaf blast among Ton1 line rice varieties were mostly distributed on flag leaf. Relation between the degree of lesion distribution and level of fertilizer was more clear with an increase of fertilizer quantity. Leaf blast lesions of rice varieties were generally distributed from the flag leaf to the with leaf from the top but mainly those at flag leaf and the 2nd leaf from the top were found to be most responsible for inoculum source of panicle blast after booting stage. Increase of the conidia formation was resulted from fluctuation of temperature$(24^{\circ}C\~16^{\circ}C)$ in low temperature range after booting stage and many inoculum sources were supplied on panicles until the end of September without impeding dispersal from leaf blast lesions as an inoculum source of panicle blast.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.258-264
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• 2000

Starches from the eight varieties of rice were analyzed using scanning electron microscope(SEM), differential scanning calorimetry(DSC) and X-ray diffractometry, and tested on the starch-granule susceptibility to 15% $H_2SO_4$ and glucoamylase. The shape of starch granules from normal rice varieties and low-amylose mutants were polygonal while shrunken and floury mutants were globular. According to DSC, starches from Nampung CB243 showed higher onset temperature$(T_o)$, completion temperature$(T_c)$ and Punchilmi, Nampung EM90 showed higher enthalpy$({\triangle}H)$ of gelatinization than others. shr showed the highest hydrolysis rate to 15% $H_2SO_4$ while Nampung CB243 showed the lowest one. Eight varieties of rice starch granules showed A-type pattern on X-ray diffractograms. The lower amylose content rice varieties showed the higher hydrolysis rate treated with glucoamylase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.765-769
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• 2001

Starches of flavored glutinous rice were analyzed by using scanning electron microscope (SEM) and differential scanning calorimetry (DSC) and tested on the starch granule susceptibility to 15% H$_2$SO$_4$, glucoamylase and $\alpha$-amylase. The shape of starch granules form flavored glutinous rice varieties was polygonal and the size was 4~6 $\mu$m in diameter. According to DSC, glutinous rice starch showed onset temperature (T$_{o}$) range 59.8~62.5$^{\circ}C$ and KR92021-B-B-42-3-B and KR92021-B-B-165-1-B showed higher enthalpy ($\Delta$H) on gelatinization than others. The starches from KR92021-B-B-5-2-B and KR92021-B-B-42-3-B showed lower hydrolysis rate using 15% H$_2$SO$_4$ than KR92021-B-B-165-1-B. KR92021-B-B-5-2-B showed higher degree of hydrolysis of glucoamylase and $\alpha$-amylase than the others.

• The Korean Journal of Ecology
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• v.15 no.2
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• pp.157-172
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• 1992

Studies were conducted to evaluate the differential al tolerance of suwon 205 and olmil wheats grown is nutrient solution and determine the impact of NH4+-N or Ca2+ nutrition of the response of the two wheat vareties to al. In various concentrations of al, olmil induced lower ph levels than suwon 205 in nutrient solutions and the reduction of root length and dry weight was greater in olmil than in suwon 205. The uptake of al was greater in root than in shoot of the two wheat varieties, but more increased in root of olimil. also the uptake of ca, mg, k and p was inhibited by al especialy decrease of ca and p uptake in roots of olmil was more pronounced than in those of suwon 205. In nutrient solutions that contained NH4+-N plus 9ppm al, the ability of both varienties to raise the ph was reduced as the level of NH4+-N in nutrient solutions was increased, and al-sensitive olimil induced lower ph than did al-tolerant suwon 205. al toxicity was intensified by increasing the concentration of NH4+-N in nurient and toxic effect was greater in olmil. al toxicity in the two wheat varieties was steadily increased as the ca level of nutrient solution was reduced, sepecialy this effect was stronger in al-sensitive olmil than in al-tolerant suwon 205.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.720-729
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• 1996

Effect of the cellulase treatment on the physicochemical properties of three varieties of rice (chucheongbyeo, chosengtongilbyeo and IR 36) and the texture of cooked rice were investigated. The swelling power and solubility of the rice flours were increased and amylographic viscosities, especially cold viscosities were decreased by cellulase treatment in all varieties. Gel chromatography of soluble carbohydrates from cellulase-treated rice flours on sepharose 2B-CL showed a singificant increase of low molecular weight $(10^{4})$ fraction which might be produced upon hydrolysis in endosperm cell wall constituents. The hardness of cooked rices prepared from cellulose-treated rices significantly decreased.

• Plant Biotechnology Reports
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• v.5 no.1
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• pp.89-103
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• 2011

Two rice varieties, viz. Nonabokra and Pokkali, have been evaluated for their responses to salinity in terms of some physiological and biochemical attributes. During the exposure to salinity (200 mM concentration of sodium chloride for 24, 48, and 72 h), a significant increase in sodium was recorded which was also concomitant with the changes of other metabolic profiles like proline, phenol, polyamine, etc. The protein oxidation was significantly increased and also varied between the two cultivars. The changes in activities of anti-oxidative enzymes under stress were significantly different to the control. The detrimental effects of salinity were also evident in terms of lipid peroxidation, chlorophyll content, protein profiles, and generation of free radicals; and these were more pronounced in Pokkali than in Nonabokra. The assessment and analysis of these physiological characters under salinity could unravel the mechanism of salt responses revealed in this present study and thus might be useful for selection of tolerant plant types under the above conditions of salinity.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.7-12
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• 2000

This study was conducted to identify useful germ plasm sources of resistance to black shank, Phytophthora. parasitica, in Nicotiana tabacum and to characterize the interaction between host plant resistance to black shank and pathogen variability. The six internationally represen-tative set of black shank resistant and susceptible tobacco genotypes and four Korean lines were tested for black shank on the field infested with P. parasitica at Chonju Experiment Station, Korea Ginseng & Tobacco Research Institute during the 1992～1997 growing season. Almost 100% of the plants of the most susceptible genotype, Ky 14, did not survive. Complete survival of (MS Ky 14 x L8)F$_1$, which is resistant to reee 0 and ausceptible to reace 1, suggests that Race 0 is the only race of the P. parasitica in this bield. Coker 371 Gold and Beinhart 1000-1 having excellent resistance to black shank could be recommended as the parental cultivars for improving black shank resistance in Korea. Data of the diseased plants showed that KB 101 and KB 110 were medium high resistant and KB 103 and KB 108 being low resistant to black shank.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.1-8
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• 1999

Starch was isolated from nine Korean sweet potato varieties(Shinmi, Seangmi, Yulmi, Shinyulmi, Sunmi, Jeungmi, Mokpo 26, Mokpo 29, and Mokpo 30) and analysed in its physicochemical properties in comparison with a commercial sweet potato starch(Kumokanyu) imported from China. Protein content in the isolated starch was highest(1.1%) in Mokpo 29 and lowest(0.3%) in Kumokanyu, whereas lipid content was equally less than 0.2%. Pasting analysis by Rapid Viscoanalyser(RVA) showed that Yulmi starch had the lowest pasting temperature(70.2oC) whereas Kumokanyu did the highest one (74.3oC). Under a differential scanning calorimetry(DSC), however, Kumokanyu showed the lowest onset temperature(61.8oC) and enthalpy(42.0 J/g) for crystal melting. Shinyulmi showed the highest peak viscosity of the starch paste, but shear thinning was significant like commercial potato starch. Kumokanyu, however, displayed the least peak visicosity but good shear stability. With the starch gels prepared at 4oC, Mokpo 29 showed the highest hardness, whereas Shinyulmi did the lowest one. Against repeated freeze thawing treatments, the starch gel of Kumokanyu was most stable, and among the Korean varieties, Yulmi, Shinyulmi, Jeungmi and Mokpo 26 had good stability. According to the chain distribution analysis, Shinyulmi and Mokpo 29 consisted of larger quanitites of shorter amylopectin chains than Kumokanyu, potato and corn starches.