The effect of 16 cultivars on the quality of the rice porridge was investigated. The ‘Geunnun’ had the highest water absorption rate, but the ‘Segyejinmi’ yield (w/w) was the highest. The total sugar content of the rice porridge was 0.29~8.10%, showing significant variation among the cultivars. High amylose ‘Dodamssal’ and ‘Hwaseonchalbyeo’ glutinous rice displayed rotational viscosities of <20,000 cP. Rotational viscosities for boiled rice cultivars were 30,000~40,000 cP, representing an intermediate level, and the rotational viscosities of ‘Geonyang2’ and ‘Hanareum4’ were over 50,000 cP. These results suggest that the viscosity of rice porridge varies significantly among raw material cultivars. Among other variables affecting the texture profile of rice porridge, there were significant differences in hardness and gumminess among the cultivars. As a raw material, ‘Baekokchal’, a kind of glutinous rice, is known to be whiter than the non-glutinous rice, but after processing to porridge, it showed the lowest L value (71.1). Starch degrading enzyme activity was not significant in most types of rice porridges within 30 or 60 minutes. Therefore, enzymatic starch degradation is thought to be completed within 30 minutes. Among the tested raw materials, ‘Miho’ was 73.5 μg/mg, indicating the best digestibility in vitro.

When producing rice products, it is very important to select suitable raw materials. Therefore, in this study, the quality characteristics of 16 rice cultivars were quantified to determine the criteria for evaluating the machinability of raw rice. The L value, which can affect the color of porridge prepared from rice, was the greatest for Hwaseonchalbyeo (84.17). The water-binding capacity, related to water interaction, was high in Hyangcheola (113.2%), and water solubility was high in Shingil (22.3%). Dodamssal (42.3%, 70.7 RVU) and Hwaseonchalbyeo (4.7%, 27.8 RVU) showed lower final viscosity compared to the cultivars in which the amylose content was medium groups (16.4~21.2%, 173.6~277.2 RVU). Specifically, cultivars with high or low amylose content had a low viscosity. The characteristics of the distribution of raw rice quality data were confirmed through 11 histograms. Furthermore, amylose content vs. water solubility, water solubility vs. peak viscosity, and peak viscosity vs. final viscosity showed high correlations (r=0.542, －0.569, and 0.836 respectively, p<0.01), and clear cultivar discrimination by the standard error of the mean (0.765~10.811). In conclusion, amylose content, water solubility, and peak viscosity were considered the most suitable characteristics for the quality evaluation of raw rice.

아열대 지역 적응 자포니카 중간모본 밀양375의 주요 농업 적 특성 및 품질관련 특성을 분석한 결과는 아래와 같다. 1. 아열대지역인 국제미작연구소에서 밀양375는 파종 후 85 일에 출수하였다. MS11보다 11일정도 늦었고, 아열대지역의 표준품종인 IR64호와 비슷하였다. 2. 주요 농업적 특성 및 수량성을 분석한 결과는 밀양375의 간장은 74.9 cm로 자포니카 품종인 MS11보다 약 5.2 cm 정도 큰 편이였고, 쌀수량은 346 kg/10 a로 MS11의 수량 262 kg/10 a보다 32% 증수되었고, IR64의 수량 337 kg /10 a와 비숫하였다. 3. 주요 품질관련 특성을 분석한 결과, 밀양375는 장폭비 1.78정도의 단원립이면서, 단백질 함량이 낮고, 아밀로스 함량 이 낮아 찰기가 양호하며, 밥의 윤기가 높은 계통이였다. 4. 주요 농업적 특성의 상관분석 결과 쌀수량과 출수기 (0.899). 수당립수(0.851), 간장 (0.832) 및 수장(0.685) 순으로 정의 상관관계를 나타내었고, 수수와 천립중은 부의 상관관계를 나타내었다. 5. phylogenetic tree를 분석한 결과는 밀양375는 국내 육성 자포니카 중만생종과 같은 그룹으로 분류되었으며, 아열대 지역 적응 자포니카 품종인 MS11과 다른 그룹으로 분류되었다. 따라서, 아열대 지역 자포니카 품종 육성을 위한 새로운 중간 모본으로 활용성이 높은 것으로 판단된다.

Since April 2012, doctor fish in the breeding tank and in the quarantine tank in Hanwha Aquaplanet Yeosu Aquarium have been dying, accompanied by diffuse bleeding around the mouth, in the chin, and at the bottom of the abdomen. In this study, the cause of death would be examined through the bacteriological study of doctor fish and the rearing water quality in the aquarium. The water quality and the bacterial counts of the rearing water in the exhibit tank and in the quarantine tank were analyzed once a week, starting from August to November 2014. Water quality was measured based on the following data: temperature was in the range of 24.5~26.8℃, pH at 6.77~7.94, DO at 6.15~8.61 ppm, ammonia at 0~0.93 ppm, nitrite at 0.009~0.075 ppm, and nitrate at 1.1~40.9 ppm. Studies revealed that the differences in these water quality factors were not related to the death of doctor fish. Bacterial counts in the rearing waters of Garra rufa slightly increased to 103~104 CFU/ml, just before the death of the doctor fish. Twelve strains of bacteria were isolated from the dead fish and rearing waters. The isolates were identified as Aeromonas veronii, Citrobacter freundii, Pseudorhodoferax aquiterrae, Shewanella putrefaciens, and Vibrio anguillarum on the basis of 16S rRNA gene sequences. The most dominant species was C. freundii, which showed medium sensitivity to florfenicol and norfloxacin, and was resistant to amoxacillin, doxycycline, oxytetracycline, tetracycline, and trimethoprim. Ten isolates were confirmed to be pathogenic to the doctor fish. Doctor fish infected with C. freundii and S. putrefaciens showed high mortality in the experimental groups. These results indicate that the variation in bacterial numbers in the rearing water was related to the death of doctor fish. C. freundii and S. putrefaciens were directly implicated in causing the death of doctor fish in the aquarium.

향후 쌀 생산량 조정과 조사료 자급률 향상을 위해 사료용 벼 재배면적이 확대될 시기에 국내 총체사료용 벼 종자생산체계 확립에 기술적 기초자료를 확보하기 위해 총체사료용 벼 주요품종의 채종적지 선정에 관해 검토한 결과는 아래와 같다. 1. 벼 재배 지대별 10개소 중 ‘녹양’은 I-2지대 남부해안지인 고성, II-1지대 호남평야지인 익산, II-2지대 영남평야지인 밀양 지역이 충실한 종자를 채종하기에 적합한 지역으로 조사되었다. 그 중에서도 고성지역에서 4월 30일에 파종하여 5월 30일에 이앙했을 때 생육, 수량 및 발아특성이 가장 좋아 채종적지로 가장 적합할 것으로 판단된다. 2. ‘목우’는 I-2지대 남부해안지인 고성, II-1지대 호남평야지인 익산지역이 우량 종자를 채종하기에 적합한 지역으로 보인다. 특히 남부해안지인 고성에서 파종시기를 앞당겨 4월 1일에 파종하여 4월 30일에 이앙했을 때 가장 건전한 종자를 채종할 수 있을 것으로 판단된다. 3. ‘목양’은 지대별로 공시한 다른 3품종과 비교했을 때 등 숙비율, 발아율 등이 대체로 낮아 다른 3품종보다는 채종적지로서의 조건이 다소 미흡하지만 I-2지대 남부해안지인 고성, II-1지대 호남평야지인 나주지역이 채종하기에 적합한 것으로 나타났다. 남부해안지인 고성에서는 ‘목우’와 마찬가지로 4월 1일 에 파종하여 4월 30일에 이앙했을 때 가장 건전한 종자를 얻을 수 있으나 평균발아율이 85%미만으로 건전한 발아를 위해서는 채종한 종자를 최소한 반드시 수선하여 사용해야 하며 수선 시에는 채종량에 비해 종자량의 손실이 많을 것으로 판단된다. 4. ‘중모1029’의 경우에는 지대별로 시험한 10개소 중에서 II-2지대 영남평야지에 속하는 대구지역이 생육, 수량 및 발아 특성을 고려해 볼 때 채종적지로 판단된다.

식물체 내에서 HPPD(4-hydroxy phenylpyruvate dioxyge-nase)를 저해하여 카로티노이드 생합성을 억제하는 제초제benzobicyclon 및mesotrione+pretilachlor의 처리 약량에 따른통일형 벼의 약해 발생 정도와 약해발생에 따른 수량영향을조사한 결과는 다음과 같다. 1. Benzobicyclon과 mesotrione+pretilachlor(MP) 처리 후6~12일에 통일형 벼인 한아름벼, 한아름2호, 다산벼는 모두잎의 백화약해 증상이 나타났고, 기준량 처리시 약해는 각각34~64%, 63~75%이었으며, 배량 처리에서는 약해발생이 더심해 각각 76~83%, 83~89% 이었다. 또한 벼식물체는 기준량 처리시 고사되지 않았으나 배량 처리시 식물체 고사율은benzobicyclon은 6.5~11.5%로 MP 2.1~3.3% 보다 고사율이 높았다.2. 출수기는 benzobicyclon 및 mesotrione+pretilachlor처리에 따른 약해로 대조인 butachlor 처리보다 1~2일 지연되었다.3. Benzobicyclon과 mesotrione+pretilachlor 처리시 통일형 벼 생육은 butachlor 처리에 비해 한아름벼, 한아름2호 및 다산벼 모두 기준량 처리시 m2 당 수수가 14~67개가 적고 등숙비율이 2.7~8.6% 낮아져으며 현미천립중이 0.0~1.2g 가벼웠다.4. Benzobicyclon과 mesotrione+pretilachlor 처리시 쌀 수량은 대조인 butachlor처리의 644~725kg/10a에 비해 한아름벼는 5~9%, 한아름2호와 다산벼는 5~8% 감소되었고, 2배량 처리시 수량감소는 더욱 증가하여 한아름벼는 16~28%,한아름2호는 20~24%, 다산벼는 14~23% 감소하였다.

Rice production is largely affected by various environmental conditions such as cold, heat and flooding. Here, to identify cold tolerant QTLs at seedling stage in rice, we generated RIL population derived from a cross between Hanareum 2 and Unkwang which are a highly cold sensitive and cold tolerant, respectively. We observed cold phenotype of this population in the growth chamber conditions and natural field conditions. For observation of cold tolerant phenotype of RIL population in the growth chamber, we treated cold stress (5~13℃) for 14 days and recovery for 4 days. When we examined the phenotype of RIL in the field conditions, temperature range in the field conditions was about 6 to 25℃ in 2015~2016. We named QTLs as Seedling Cold Tolerant (SCT) in growth chamber and Cold induced Yellowing Tolerant (CYT) in the field, respectively. Three QTLs for SCT and 5 QTLs for CYT were detected on chromosome 1, 6, 7, 8, 10, 11 and 12. Among these QTLs, qSCT12 on chromosome 12 showed 26.3 LOD score with 25.5% of phenotypic variation. When qSCT11.1 and qSCT12 were combined, cold tolerant was most strongest in our experimental conditions. qCYT10 on chromosome 10 was identified in field experiment on both 2015 and 2016. These results may provide useful information for a marker-assisted breeding program to improve cold tolerance in rice.

To fit the market demands for functional rice such as black and red color rice, ‘Sugary’a high free sugar content line was backcrossed to the black rice ‘Milyang152. The pedigree method was adapted in selection and generation advance. A high polyphenol content line, YR19646-3-2-1-1-2-2 showing red pericarp was selected and designed as ‘Milyang234’ followed by variety name ‘Geonganghongmi’ in 2010. Heading date of ‘Geonganghongmi’ was Aug. 19, medium-late maturing cultivar. ‘Geonganghongmi’ showed resistance to leaf blast and rice stripe virus while susceptible to major diseases and insects. The total polyphenol content of ‘Geonganghongmi’ was high as much as 24.2mg/g compare to that of 4.9mg/g of ‘Nampyeongbyeo’ and 17.2mg/g of a red pericarp rice ‘Jeogjinju’ at 70% ethanol extraction conditions. In local adaptability tests, yield of ‘Geonganghongmi’ was 4.5MT/ha about 86% of ‘Nampyeongbyeo’ and 102% of ‘Jeogjinju’, respectively. ‘Geonganghongmi’ is suitable for southern and middle plain area of Korea.

Blast resistance of 29 rice cultivars confirmed as a durable resistance in the evaluation of sequential planting from 2004 to 2006 was evaluated to nursery screening in 14 test sites during 11 years in Korea. The average disease severity (ADS) of 29 rice varieties against rice blast showed 3.5 degree; however, the difference of disease severity among the varieties was from 1.9 to 4.8. The 29 varieties were grouped into resistance less than 3.0 ADS degree including 12 varieties and moderate resistance over 3.1 ADS degree including 17 varieties. Among the 12 rice cultivars presented low ADS, 4 rice cultivars, Ungwang, Pungmi 1, Sinunbong 1, and Dasan 1 were constantly appeared high resistant reaction during 11 years in all test sites and the others were showed various diseases severity across the test years and the test sites. Twenty-one rice cultivars including Gopum were more variable among the test sites while the others were higher variable among the test years. These results indicated that durable resistance test against rice blast using sequential planting is a very efficient screening method to predict durability and nursery test for long periods and also useful method to predict indirectly durable resistance of rice cultivars.

Jungmo1019 early maturing rice variety was developed by the rice breeding team of the Department of Southern Crop, NICS, RDA in 2011. This cultivar was derived from the cross Hwayeongbyeo//Hitomebore/Nampyeongbyeo made in 2005 and the production of doubled haploid rice plant from anther culture in F1 generation. Testing in the replicated yield trial in 2008, a promising line YR25312Acp62 was selected and it was designated as the Milyang246. The early traus plauting local adaptability test of Milyang246 was carried out at three location in 2011 and it was named as Jungmo1019 showing a high head rice ratio and early–maturity eco-type. Number of spikelet/panicle and 1,000 grain weight of brown rice was slightly lower than those of Jopyeongbyeo. This variety is resistant to bacterial blight, rice stripe virus disease but susceptible to major insect and pests. The milled rice yield of Jungmo1019 is 4.52MT per ha at the early transplanting of the local adaptability test. This line should serve as a useful source for improving head rice ratio at early transplanting cultivation in southern plain area.

The amylose contents of rice determine eating quality which is one of the major traits in rice breeding program. To identify the low-amylose gene of the japonica rice cultivar Baegjinju, genetic analysis was conducted using 200 F2 population derived from a cross between the japonica cultivars, Saeilmi and Baegjinju. Individual F2 plants were classified as wild type (translucent grain) and mutant type (dull grain) based on the grain appearance of brown rice. Two hundred F2 plants were segregated into 155 wild type plants and 45 mutant type plants, which fit the 3:1 ratio (x2 = 0.667, df = 1, p = 0.414) and this result indicated the low-amylose gene of Baegjinju is a single recessive gene which controls the amylose contents. Linkage analysis was conducted to localize the low-amylose gene of Baegjinju and fine mapped within an 800-kb interval between 17.5 to 18.8Mb on short arm of chromosome 10. Co-segregated SSR marker, RM25648 was developed and it could be useful for marker-assisted selection and determination of the genetic resource related with amylose contents in rice breeding.

Bakanae (foolish seedling) disease caused by Gibberella fujikuroi creates serious problems in the foremost rice growing countries. This study was conducted to identify new resistance genetic sources to Bakanae disease. Bioassay showed that 11 varieties including Gwangmyeongbyeo, Hawn, Wonseadaesoo, Erguailai etc. were resistant to bakanae disease among 254 rice germplasm. Mismatch ratio between phenotype on bakanae disease bioassay and allele type of RM9, a SSR marker closely linked the bakanae disease resistant QTL, qBK1, were 38.3%. These results suggest that RM9 might be used for selecting qBK1, but it cannot be used for wide range of rice germplasm. Resistant germplasm in this study might be have resistant genes different from qBK1. The eleven varieties resistant to selected in this study will be used to identify new resistant alleles or genes to improve bakanae disease resistance in rice.