• Journal of Mushroom
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• 제16권3호
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• pp.186-191
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• 2018

In order to breed a new Pleurotus eryngii cultivar with a large pileus and convex shape, which are favorite traits of customers from Europe and North America, single crosses between monokaryotic mycelia derived from basidiospores of KNR2555 were performed to yield the new cultivar $2{\times}12$ chosen by cap shape (convex), diameter of pileus (60.7 mm), and quality (4.9) in a preliminary cultivation. The strain was named Gat_aeryni and was cultivated on a large scale for comparison with Kenneutari 2 ho at the GNARES and at mushroom farms. The yield of Gat_aeryni (71.7 g) was not significantly different from that of Kenneutari 2 ho (71.4 g), and the quality of the new cultivar was 6.8, which was not significantly different from that of a reference cultivar (6.5). Days for harvest, length, and diameter of the pileus in the two cultivars were statistically different by an independent t-test (P < 0.001, P < 0.05, P < 0.001 and P < 0.05 respectively). The new and reference cultivars were discriminated by PCR reactions with a primer set (URP1 and URP10) and simultaneous cultivation.

• Parasites, Hosts and Diseases
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• 제50권3호
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• pp.191-197
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• 2012

Seroepidemiological changes of Toxoplasma gondii infection among the residents of the islands of Gangwha-gun, Incheon for 2 years were surveyed and evaluated by ELISA using a crude extract antigen. In 2010, sera of 919 adult residents in Gyodong-myeon and 313 adults in Samsan-myeon were collected and checked for IgG antibody titers, which showed 14.5% (133 sera) and 19.8% (62 sera) positive rates, respectively. In 2011, sera of 955 adults in Gyodong-myeon and 341 adults in Samsan-myeon were examined, which showed an increase of positive rates to 23.8% (227 sera) and 31.7% (108 sera), respectively. Totally, the seroprevalence of the first year was 15.8% and it increased rapidly to 25.8% in the second year. The positive rates of both sexes increased simultaneously with the significant ratio of males to females by 1.7-2.2 fold (P<0.05). In both myeons, 661 sera were collected every year and showed changes in optical density (OD) in 177 sera; newly found as positives in 73 persons (11.0%), negative conversion in 10 persons (1.5%), and maintained or increased in 94 persons (14.2%). This rapid increase in the prevalence of toxoplasmosis in Gangwha islands may be due to in part peculiar changes in the toxoplasmic environment of the islands and presumably the consumption of the pork bred domestically within the islands or imported from high endemic nations. It is necessary to find out symptomatic toxoplasmic patients and confirm the risk factors for further infection in the islands of Gangwha-gun.

• Research in Plant Disease
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• 제7권2호
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• pp.86-92
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• 2001

This experiment was carried out to analyze the recent epidemic of rice blast in southern provinces of Korea in 1999 and 2000. Incidences of leaf blast and panicle blast in these years were 1.5 and 2.9 times greater than those in 1998, respectively. Cultivation areas of rice cultivars, Daesan, Ilmi and Dongan bred from Milyang 95 as a recurrent parent increased over the country from 11% in 1998 to 38.4% in 2000, which were grown in more than 85% of total paddy fields in Jeonnam province. Predominant race populations of Pyricularia grisea in the farmers' fields had been changed from KJ-301 to KI-1117 in 1999 and KI-1113 and KJ-105 in 2000. Distribution ratio of the KI-1117 race in 1998 in the southern provinces was 1.7%, but increased to 30% in 1999. Although the cultivars Daesan, Ilmi and Dongan have shown wide spectrum of resistance to many races including KJ-301, they were susceptible to such races as KI-1117, KI-1113 and, KJ-105. These three races could be further classified into two sub-races, KI-1117 and KI-1117a, KI-1113 and Kl-1113a, and KJ-105 and KJ-105a based on virulence to Daesan. The newly classfied races, Kl-1113a, Kl-1117a, and KJ-l05a were also pathogenic to Ilmi and Dongan. This indicates that rice blast epidemic in southern provinces in 1999 and 2000 resulted from the breakdown of the resistance of Daesan, Ilmi and Dongan by the rapid increase of virulent races KI-1117, KI-1113, KJ-105 and their new sub-races.

• Korean Journal of Environmental Agriculture
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• 제34권4호
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• pp.288-293
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• 2015

BACKGROUND: This study was conducted to investigate the effect of the unexpected early loss of leaves on a newly-bred kiwifruit on the regrowth of axillary buds the current season and the early growth and development the following year.METHODS AND RESULTS: The vines were defoliated on Jul. 18, Aug. 16, and Sep. 17 in 2012 and on Jul. 16, Aug. 13, and Sep. 12 in 2013. The vines were defoliated 0 (control), 50, and 100% of the total number of leaves on a vine. The regrowth of axillary buds at 30 days after defoliation increased in proportion to defoliation degrees regardless of the defoliated time. Defoliation the previous season did not influence percent budbreak the next season. Percentage of floral shoots of the control vines was 27.4%, each bearing 2-3 flowers. In those vines defoliated 100% in August and September, however, percent floral shoots and number of flowers significantly reduced.CONCLUSION(S): Defoliation in July, August, and September didnot affect percent budbreak the following year regardless of degrees of defoliation. A 100% defoliation in August and September significantly reduced flowering the following year compared to the control; that in August resulted in no floral buds at all.

• Korean Journal of Agricultural Science
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• 제4권1호
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• pp.26-33
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• 1977

We have studied the responce of nitrogen on the newly bred varieties, Yusin and Milyang #23, and the effects of defoliation at maturing stage on the rate of ripened grains under different nitrogen levels. The results obtained are summarized as follows : 1. Milyang #23 as well as Tongil was found to be highly nitrogen responsive variety and showed good grain maturing percentage. The number of grain per unit area affected the total yield under the high levels of nitrogen application. The variety, Yusin, was less responsive to nitrogen and had also less leaf area than other varieties under the high level of nitrogen application. Yusin also seemed to have low maturing percentage due to unbalanced ratio between photosynthetic area and size of storage. 2. The low internodes and leaf blade of Yusin and Milyang #15 were grown too much under high levels of nitrogen and these caused more lodging and less light penetration in pant canopy. 3. The effects of defoliation at maturing stage on yield was high under the high levels of nitrogen application, especially when defoliation was done early stage of maturing. The effects of defoliation appeared to be greates in Tongil than in Milyang #15.

• Journal of the Korean Society of Food Science and Nutrition
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• 제40권8호
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• pp.1179-1183
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• 2011

This study was conducted to investigate the quality characteristics, antioxidant activity, and ${\alpha}$-glucoamylase inhibitory activity of Dahyang, a Chungnam Agricultural Research & Extension Service's newly bred cultivar of brown button mushroom. Total phenolic compound contents of Dahyang and the no. 705 mushroom were 189${\pm}$12 mg% and 168${\pm}$8 mg%, respectively. The major free sugars in Dahyang were mannitol (3.11%), xylose (0.12%), and trehalose (0.08%). ${\beta}$-Glucan content was 28.34% in Dahyang and 26.55% in the no. 705 mushroom, respectively. Electron donating ability by DPPH in Dahyang and the no. 705 mushroom was 52.14% and 45.27% for the water extract, and 57.81% and 46.93% for the 80% ethanol extract, respectively. ${\alpha}$-Glucoamylase inhibitory activity in a 10 mg/mL concentration of water extract were was 33.25% in Dahyang and 29.22% in the no. 705 mushroom, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제26권2호
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• pp.137-145
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• 1981

Using the milled, blast infected leaves (BIL) as an inoculum source on the screening for the resistance to blast of rice plant was a simple and useful technique. The temperature with high (25^\circ C\sim 35^\circ C) and low (15^\circ C\sim 28^\circ C) and the water stressed or not, was conditioned of to the inoculation with the BIL to the test varieties in seedling stage. In low temperature, most of the varieties were more infected with blast, however the Indica-Japonica hybrids were more infected in high temperature conditions. The water stressed was more infected with blast than the not stressed. The interaction of variety with water stress was not so much as that of variety with temperature. Resistant reaction to blast (BIL) was not affected by the temperature and water stress, but the moderately resistant or susceptible one was much affected by them. Inoculum of BIL was virulent to the newly bred Indica-Japonica hybrid cultivars such as Tongil, Nopung, etc, but not virulent to the Japonica cultivars such as Nongbaek, Jinheung, etc. The discrete, mixed or variable lesions were observed mainly in the moderately resistant or susceptible cultivars such as Kanto 51, Yashiromochi, Ishikari-shiroke, etc.

• Journal of Mushroom
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• 제20권3호
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• pp.147-152
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• 2022

To develop mushroom varieties for cultivating at low temperature on oak logs, a strain with a low fruiting body generation temperature was crossed with Di-mon to select for a line with excellent properties. Selection was followed by cultivation testing. From these studies, Heunghwa 1ho was identified. The optimum temperature for cultivating Heunghwa 1ho, was 13.3℃. The fruiting temperature range was 6.4~20.2℃, identical to that of the parent strain. Growth at 25℃ for 7 days achieved optimal mycelial growth of 61.9±2.10 mm, superior to growth of the parent strain at this temperature. The cap shape of Heunghwa 1ho was convex, cap diameter was 57.8±8.31 mm, and cap color was brown. Heunghwa 1ho showed similar genetic traits to those of the parental strain. However, dry weight (20.1 kg/m³) and cap diameter and color are superior to those of the parent strain. The 3 year fresh oak mushroom yield was 113.8 kg/m³, superior to the respective yields of the parent strains JMI 10047 and JMI 90021 (92.5 kg/m³ and 66.4 kg/m³).

• Korean Journal of Soil Science and Fertilizer
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• 제8권2호
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• pp.105-111
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• 1975

Nitrogen efficiency for grain yield(E) and its relation to grain yield(Y), harvesting index(HI), percent translocation of nitrogen from straw to grain(T), nitrogen uptake amount(N), concentration in grain (GN%) or straw (SN%) and total dry matter yield (TY) among rice varieties (Oryza sativa, old and new varieties) were investigated at four nitrogen nutritional status (high and low fertilizer levels in high and low fertility fields) by simple correlation analysis. Relation between any two of above parameters or total dry matter yield (TY) and nitrogen efficiency for total dry matter yield (TE) was also investigated. 1. E is significantly and positively correlated with T, Y, HI but negatively with SN%, N, GN% and in negative trend with TY. 2. T is significantly and positively with GN% or Y, but negatively with SN%. 3. TE is significantly and positively correlated with TY but negatively with N. 4. The order of E among varieties showed consistency among different nitrogen nutritional environments. 5. From the above facts it was concluded that high yielding varieties have high nitrogen efficiency due to high percent translocation of nitrogen from straw to grain, subsequent low nitrogen concentration in straw and that translocated nitrogen in grain is greatly diluted with photosynthates. 6. Reported physiological characteristics of newly bred high yielding IR lines are well accordance with their high nitrogen efficiency and rice breeding was a selection on the basis of nitrogen efficiency. 7. It is postulated that high nitrogen efficiency varieties for yields have high nitrogen efficiency for root growth in early stage so that uptake more efficient soil nitrogen in later growth stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제51권3호
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• pp.233-238
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• 2006

This study was conducted to evaluate growth characteristics, yield and feed value of newly bred domestic silage corn hybrids compared to foreign imported corn hybrid. Days to silking were $78{\sim}86$ days and longer than that of P3394 (Control). Kwangpyeongok, Cheonganok, and Cheongsaok were resistant to lodging. Such trait of stay-green of Kwanganok, Kwangpyeongok, Cheonganok, Cheongsaok, and Suwon159 was not different from that of P3394. Duruok, Kwangpyeongok, and Suwon159 were more resistant to Bipolaris maydis (southern corn leaf blight) than P3394. All of the silage corn hybrids were resistant to Exserohilum turcicum (northern corn leaf blight) and Smut. Ear ratios to total dry matter (%) of Cheonganok was similar to P3394. Ear lengths of domestic hybrids were similar or longer than that of P3394. Dry matter yield of domestic hybrids except Suwon19 and Jangdaok were similar to that of P3394. Total digestible nutrient (TDN) yields, Duruok, Kwangpyeongok, Cheonganok, and Cheongsaok were similar to P3394, but Kwanganok, Suwon19, Jangdaok and Suwon159 were lower than P3394. Acid detergent fiber(ADF), Suwon19 was lowest among all hybrids, and all hybrids except Suwon19 had values ranging from 44.7 to 49.0%, similarly with P3394. Neutral detergent fiber (NDF) values of the hybrids were similar to that of P3394, and ranged from 68.1 to 72.8%, except for Duruok which was lowest. Relative feed values (RFV) of Duruok, Kwangpyeongok, Cheonganok, Jangdaok, and Suwon159 had values ranging from 71.0 to 75.7 and were not significantly different from P3394. ADF was significantly negatively correlated with number of days to silking, number of days to maturity, and fresh matter yield, but was significantly positively correlated with resistance to corn borer. RFV showed a significantly positive correlations with no. of days to maturity and fresh matter yield, but significantly negative correlation with resistance to European corn borer. Therefore, indices for evaluation of feed value as well as production were important to select corn hybrids for silage. It is concluded that domestic hybrids tested in this study have high feed value as well as high production similar to those of imported corn hybrid.