• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.109-115
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• 2007

This study was carried out to determine occurrence and damage of golden apple snail, Pomacea canaliculata on water seeding area in Jeonnam province. The density of golden apple snail maintained hlgh until October 2003, but quickly decreased from November. They overwintered only in a portion of the water canals but could not find in dried paddy field. They reproduced from May and June in the canal water and paddy field, respectively. Feeding time of golden apple snail on rice seedlings was 235.2 seconds, feeding length of that was 8.4cm. When golden apple snail fed rice seedlings, the stem remain only 2.5cm from areal part which could not recover. The more density of golden apple snail, the fester feeding rate. Density and number of eggs laid of golden apple snail after overwintering was higher on bank around of paddy field than on middle of that. The percent of shell size after over wintering was higher in small (below 25mm) than big (over 36mm). But in case of Boseong area, the slze was reverse because the soil has soft mud. The survival rate of overwintering golden apple snail was lower than that of breeding. They did not move when the temperature changed rapidly, but the temperature increased they start to move. They dead almost below $-3^{\circ}C$. The damage of rice by golden apple snail in the direct water seeding was 20%. In machine transplanting, rice damaged only fore-end of leaf and recovered subsequently. When golden apple snail release in direct water seeding field, the percent of damage was 5.6% in immediately release plot. The later release, the lower damage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.172-181
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• 2020

Koshihikari has been one of the most popular rice cultivars with good eating quality since the 1960s despite its susceptibility to blast disease and lodging. To map the genes controlling blast resistance and to develop promising blast-resistant breeding lines inheriting Koshihikari's high eating quality, a recombinant inbred line (RIL) population was developed from a cross between Koshihikari and a blast resistance donor with early maturity, Baegilmi. A total of 394 Koshihikari × Baegilmi RILs (KBRIL), and the two parents, were evaluated for blast resistance and major agronomic traits including heading date, culm length, panicle length, and tiller number. A linkage map encompassing 1,272.7 cM was constructed from a subset of the KBRIL (n = 142) using 130 single nucleotide polymorphisms. Two quantitative trait loci (QTL) for blast resistance, qBL1.1 harboring Pish/Pi35 and qBL2.1 harboring Pib, were mapped onto chromosomes 1 and 2, respectively. qBL1.1 was detected in both of the experimental sites, Namwon and Jeonju, while qBL2.1 was only detected in Namwon. qBL1.1 and qBL2.1 did not affect agronomic traits, including heading date, culm length, panicle length, and tiller number. From the 394 KBRILs, lines that were phenotypically similar to Koshihikari were selected according to heading date and culm length and were further divided into the following two groups based on blast resistance: Koshishikari-type blast resistant lines (KR, n = 15) and Koshishikari-type blast susceptible lines (KS, n = 15). Although no significant differences were observed in the major agronomic traits between the two groups, the KR group produced a greater mean head rice ratio than the KS group. The present study provides useful materials for developing blast-resistant cultivars that inherit both Koshihikari's high eating quality and Baegilmi's blast resistance.

• Research in Plant Disease
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• v.22 no.4
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• pp.264-268
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• 2016

The nursery test against rice blast in Korea from 2014 to 2015 was analyzed. The average of disease severity of leaf blast in 12 sites showed $3.7{\pm}2.1$ in 2014 and $4.4{\pm}2.1$ in 2015. Disease severity of leaf blast in Icheon and Cheolwon was increased ranging from $2.8{\pm}2.2$ in 2014 to $6.3{\pm}1.8$ in 2015. Using a designation system, a total of 588 isolates collected those years were categorized into 34 races in 2014 and 51 races in 2015 based on the reaction pattern of Korean differential varieties. The blast isolates of 2015 were more diverse than those in 2014. The ratios of KI race to KJ race were 54:46 in 2014 and 70:30 in 2015; however, the predominant race population was KJ-301 as 16%, and KI-101 as 15% in 2014 and 2015, respectively. These results indicate that the distribution of the blast races is getting more diverse in Korea, therefore, this research would provide the possibility to predict race distribution and change to prevent the outbreak of rice blast and will also serve as a useful information for breeding of resistant rice cultivar against blast.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.498-514
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• 2018

A statistical analysis for 3651 genetic resources collected from China (1,542), Japan (1,409), Korea (413), and India (287) was conducted using normal distribution, variability index value (VIV), analysis of variation (ANOVA) and Ducan's multiple range test (DMRT) based on a data obtained from NIRS analysis. In normal distribution, the average protein content was 8.0%, whereas waxy type amylose and common rice amylose were found to be 8.7% and 22.7%, respectively. The protein contents ranged from 5.4 to 10.6% at the level of 95%. The waxy amylose and common rice amylose ranged from 5.9 to 11.5%, and from 16.9 to 28.5% at 95% confidence level, respectively. The VIV was 0.59 for protein, 0.64 for low amylose, and 0.81 for high amylose contents. The average amylose contents were 18.85% in Japanese, 19.99% in Korean, 20.27% in Chinese, and 25.46% in Indian resources, while the average protein contents were found to be 7.23% in Korean, 7.73% in Japanese, 8.01% in Chinese, and 8.17% in Indian resources. The ANOVA of amylose and protein content showed significant differences at the level of 0.01. The F-test for amylose content was 158.34, and for protein content 53.95 compared to critical value 3.78. The DMRT of amylose and protein content showed significant difference (p<0.01) between resources of different countries. Japanese resources had the lowest level of amylose contents, whereas, the lowest level of protein content was found in Korean resources compared to other origins. Indian resources showed the highest level of amylose and protein contents. It is recommended these results should be helpful to future breeding experiments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.1-5
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• 1972

In order to compare the analytical efficiency of the Kjeldahal, Dye binding and Biurett method for the determination of nitrogen content in the brown rice, correlation coefficients were calculate with the analytical data obtained by the above mentioned 3 different methods for the brown rice of 36 varieties or lines grown at 5 different nitrogen levels (0, 7.5, 15.0, 22.5 and 30.0kg/10a). Analysis of variance were made for the data of 6 varieties among those 36, and compared the precision of the data obtained by the 3 analytical methods. The expenditure (in terms of chemicals and labour) required for the 3 methods are also compared. The results are summarized as follows; 1. The correlation between D. B. C. and Kjeldahl value were generally more significant than the correlation between the value of Biurett and the value of Kjeldahl. But, the D. B. C. method generally overestimates than the Kjeldahl method at both extreme low and extreme high nitrogen contents, and the Biurett method includes more dispersed error than other two methods, though the optical values are parallel to the Kjeldahl nitrogen values at any levels of nitrogen applied. 2. The varietal difference in nitrogen value obtained by the 3 methods were different at the different nitrogen level applied. That is the interaction between variety and analytical method, and between the nitrogen level and analytical method were significant statistically. 3. The coefficient of variance (C, V.) was largest in the data analyzed by Biurett method and next in the data analayred by D. B. C. method. In the data analyzed by Biurett, the C. V. increased along onglong increase of nitrogen applied. But, in the data obtained by D. B. C. or Biurett the C. V. increased along the decrease of nitrogen applied. 4. From the comparison of the expenditure (in terms of chemicals and labour) required for the analysis of 100 samples by 3 methods, it was noticed that, the Biurett or D. B. C. method largely curtail the chemical expenditure and labour costs. Especially the Biurett method could curtail more labour costs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.123-137
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• 2015

This study was carried out to investigate the effect of pre-germination soaking on germination in 90 Korean soybean varieties and identification of protein in seeds of 7 soybean varieties. The results obtained that germination rate of soybean seeds was decreased as amount of soaking water and soaking duration in number of days. Difference in germination rate of soybean seeds was significant at three days soaking with water volume of 90 ml. Water absorption of seeds was rapidly increased during the first 6 hours, followed by slow increase until 24 hours and then decreased 24 to 48 hours after soaking soybean varieties for bean sprout soaked the lowest amount of water, while soybean varieties for cooking with rice showed the lowest seed water content. Dissolved oxygen (DO) in soaking water was rapidly decreased during the first 3 hours after soaking, and then slowly decreased. Soybean varieties for vegetable and early maturity showed the lowest DO during early soaking periods, but showed higher DO after 24 hours than other groups of soybean varieties. Electrical conductivity and Total Dissolved Solid (TDS) were increased as number of soaking days increased. Soybean varieties for vegetable and early maturity showed the highest electrical conductivity and TDS, followed by those for sauce and paste or cooking with rice, while showed the lowest electrical conductivity and TDS, varieties for bean sprout. Among 90 Korean soybean varieties, varieties which showed the highest germination rate were Jangsu-kong for sauce and paste, Sobaegnamul-kong for bean sprout, Seonheuk-kong for cooking with rice, Seunnokkong for vegetable and early maturity. On the ather hand varieties which showed the lowest germination rate were Iksan and Songhak-kong for sauce and paste, Pangsa-kong for bean sprout, Jinyeul-kong for cooking with rice, Sinlok-kong for vegetable and early maturity. Germination rates of soybean seeds were higher when electrical conductivity, TDS and water absorption of seeds were lower. There were negative correlations between electrical conductivity, TDS and water absorption of seeds and germination rate, while there were positive correlations among electrical conductivity, TDS and soybean seed weight.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.26-32
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• 2014

'Dahan' (Avena sativa L.), a winter oat cultivar for forage use, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute Crop Science (NICS), Rural Development Administration (RDA) in 2011. It was derived from an original cross between $F_1$[Sprinter/73625] and 'Gwiri26'. Subsequent generations followed by the cross were handled in bulk and pedigree selection programs at Suwon. A line, 'SO99027-GB-B-113-4-4-3', was selected for cold tolerance and good agronomic characteristics and as a line name of 'Gwiri75'. The line 'Gwiri75' was subsequently evaluated for cold tolerance and forage yield during 3 years in four region such as Yesan, Iksan, Kimjae, and Jeju, from 2009 to 2011 and finally named as 'Dahan'. Though similar in heading date to the check cultivar Samhan, 'Dahan' had tall plant length and lodging resistance. It's average forage dry matter yield harvested at milk-ripe stage was 15.6 ton $ha^{-1}$, compared with 14.1 ton $ha^{-1}$ of check cultivar. Cultivar 'Dahan' was lower to the check cultivar 'Samhan' in protein content (8.4% and 9.9%, respectively), while it was superior to the check cultivar in total digestible nutrients (TDN) (60.8% and 59.3%, respectively), and in TDN yield $ha^{-1}$ (9.5 ton and 8.4 ton, respectively). Fall sowing of 'Dahan' is recommended only in the areas where daily minimum mean temperatures are averaged higher than $-7^{\circ}C$ in January, and excluded in mountain area where frost damage is presumable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.187-194
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• 2010

The soybean stay green mutant genotype (SSG) derived from the nuclear gene, d1d2, and cytoplasmic gene, cytG, inhibit the breakdown of chloroplast in the leaves, pod walls, seed coats, and embryos during maturity. Soybean seed with black seed coat and green cotyledon (SBG) are preferred than black seed coat with yellow cotyledon (SBY) especially for cooking with rice and as source of traditional food in Korea. The researchers evaluated the seed's chlorophyll content of SSG and introduced SSG to the SBG variety breeding program. The seed chlorophyll content of SSG with d1d2 was $39.93{\sim}60.80\;{\mu}g/g$ and SSG with cytG $38.08{\sim}39.89\;{\mu}g/g$. The Korean SBG variety which was derived from SSG with cytG, contains $16.35{\sim}37.73\;{\mu}g/g$. The composition of seed chlorophyll differs according to the genetic background of SSG genotype. Inheritance study showed that cotyledon color was segregated 15:1 (yellow:green) at $F_2$ seed indicating two recessive genes control green cotyledon as revealed by previous study. Only less than 3% soybean lines showed black seed coat with green cotyledon among crosses SBY and SSG (d1d2). Results showed that SSG with d1d2 can be used as a good source for SBG with high chlorophyll content in the seed cotyledon, but due to the complex genetic behavior, breeding resource of SBG with d1d2 should be prepared to improve the breeding efficiency for development SBG variety.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.684-689
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• 2010

'Sangwon', a new cultivar for vegetable soybean, was developed from the cross between 'Keunolkong' and 'Oshimamidori', and was released at the National Institute of Crop Science (NICS) in 2007. The goal to develop a vegetable soybean cultivar with green pod, early maturity, large seed size, high yield, lodging tolerance, and resistance to disease such as soybean mosaic virus (SMV). 'Sangwon' has light green pod, early maturity, large seed, short plant height, and lodging tolerance. 'Sangwon' has determinate growth habit, white flower, gray pubescence, and oval leaf shape. The matured seeds have a yellow seed coat with light brown hilum, and a yellow cotyledon. 'Sangwon' has 5.8 cm fresh pod length, 13.2mm fresh pod width, 69.5 g seed weight per 100 green seeds, 44.0% green seed protein content, and 14.8% green seed oil content. At the regional yield trials (RYT) for vegetable soybean from 2005 to 2007, 'Sangwon' shows strong resistance to soybean mosaic virus (SMV) and tolerance to lodging in fields. Fresh pods of 'Sangwon' were harvested at the beginning of August. In the same tests, fresh pod of 'Sangwon' (10.39ton/ha) yielded 5% higher than 'Hwaeomputkong' (9.90ton/ha).

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.474-478
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• 2008

A new covered barley variety, "Geungangbori" was developed from the cross between Milyang 55 which have lodging tolerance and easy brittleness and Suweon 260 with good quality by barley breeding team in the Yeongnam Agricultural Research Institute (YARI) in 2002. A promising line, YMB3855-3B-14-1-1-1, was selected in 1999. It was designated as the name of Milyang 110. It was prominent and had good result from regional adaptation yield trials (RAT) for three years from 2000 to 2002 and released as the name of "Geungangbori". Geungangbori is resistant to barley yellow mosaic virus and moderately resistant to powdery mildow. The average maturing date was same with Olbori on paddy field in regional adaptation yield trials for 2000-2002. Its culm length is 17 cm shorter than that of Olbori and the spike length is 4.4cm, it's longer than olbori. The 1,000 grain weight of Geungangbori was 34 g, same as Olbori, but the number of spikes per $m^2$ and test weight ware lower than those of Olbori. The yield potential of Geungangbori was 4.22 MT/ha on paddy in regional adaptation yield trials for 2000-2002. which was 7% higher than that of Olbori. The cooking quality of Geungangbori were similar to Olbori such as water absorption rate and expansion rate. But the crude protein content is lower than Olbori. This variety is suitable for double cropping system with rice in the southern part of the Korean Peninsula.