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.

We investigated the change of growth characters by over-expressing OsPT6 (OsPT6-OX) under phosphorus (Pi) deficient condition in rice. In analyzing the change of growth rate according to Pitreatment for two weeks, shoot growth rate of OsPT6-OX was increased in Pi deficient condition than in Pi sufficient condition. Therefore, the chlorophyll content of leaf in OsPT6-OXs did not increase even decreased in the youngest leaf. However growth rate of wild type plant in Pi deficient condition showed significant reduction with increment of chlorophyll content. In analyzing agronomic characters, the tiller number of OsPT6-OX less decreased than those of wild type plant in Pi deficient condition. Panicle number and ripening rate of wild type plant were changed according to Pi treatment. However those of OsPT6-OX did not change in such conditions. Resulting of changes in agronomic characters, yield of wild type plant decreased about 10 % in Pi deficient condition. That of OsPT6-OX did not show significant difference in Pi deficient condition. The results obtained this study demonstrated that over-expression of OsPT6 could increase phosphorus deficient stress resistance in rice.

Alfalfa weevil, Hypera postica Gyllenhal, is regarded as one of the most important insect pests on Chinese milk vetch and hairy vetch. The insect usually feed on leaves, stems and pods of the green manure which causes severe reduction of biomass. This study was conducted to observe the occurrence of H. postica larva and adult on Chinese milk vetch in 2009 to 2010, and to evaluate host plants preference of 11 different seedlings in 2010, Milyang, Korea. Occurrence of H. postica larvae on Chinese milk vetch was observed to increase from early April clearly and its peak population was showed during middle to late April. The 1st generation of newly emerged adult of H. postica was appeared on 20th May. Newly emerged H. postica adult was fed on green manure such as Chinese milk vetch and hairy vetch as well as various seedlings located at nearby upland. And then the insects were migrated into aestivating places in middle to late of June. Thus, host plant preference of H. postica adults were evaluated with 11 different seedlings using transparent acrylcage and at Chinese milk vetch field. As a result, H. postica adult preferred on Chinese cabbage, followed by soybean, kale, foxtail millet and proso millet. The damaged rating of seedlings were shown to have the same trend with adult occurrence. In particular, few H. postica adults were occurred on eggplant, lettuce, corn, crown daisy and peanut, and thereby those crops were regarded as non-preference plants due to the absence of damage. These informations can be used by upland farmers who sowing from late May to early June for effective management of H. postica.

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.

Drought caused by global climate change is one of serious problems for rice cultivation. However, it was little reported the impact of drought on rice cultivation in Korea. In here, to assess impact of drought on rice varieties in Korean climate condition, growth characteristics and yield components of rice were compared on irrigated and partially irrigated rice paddy field. First, we have chosen 11 rice varieties including ‘Saeilmi’ and ‘Shindongjin’ which are widely cultivated in Korea. For partially irrigated rice paddy treatment, we have withheld irrigation from 25 days after transplanting and water supply was totally dependent on rainfall for rice cultivation. When we examined early plant height and tiller number of these varieties on partially irrigated rice paddy were reduced 1.6% to 18.4% and 10.4% to 33.1%, respectively, and these reduction rate were highly correlated with yield loss in our experimental conditions. Among rice yield components, panicle number was decreased 10.5% to 30.1% according to rice varieties and reduced panicle number was highly correlated with yield loss. Grain number per panicle, grain filling rate and 1,000 seeds weight did not have correlation with yield loss of rice varieties. These result means that growth stage, especially the tillering stage, is seriously affected by drought on rice cultivation in Korea. And we suggest that ‘Saeilmi’, ‘Ilmi’ and ‘Ilpum’ are good for rice cultivation on drought prone rice field in Korea.

‘온다미’는 국립식량과학원 상주출장소에서 중산간지 재배 에 알맞은 고품질 벼를 육성하고자 2003년 하계에 고품질인 히토메보레를 모본으로 하고 중산간지 적응성 조생 상주27호 를 부본으로 인공교배하여 F3이후 계통육종법에 의하여 육성 선발하면서 주요 농업형질 조사 및 병해충, 미질검정을 실시 하였다. 2010 ~ 2011년 생산력검정을 실시한 결과 내도복이 며 수량성이 우수한 YR24905-129-3-1-1-3 계통을 선발하여 ‘상주46호’로 계통명을 부여하였다. 2011 ~ 2013년 지역적응 성시험을 실시한 결과 대조품종에 비해 수량성이 높고 내도 복성, 내수발아성 및 도열병에 강하며 외관품위와 도정특성이 매우 우수하여 2013년 12월 농촌진흥청 직무육성 신품종선 정위원회에서 신품종으로 선정하고 ‘온다미’라 명명하였고, 남부중산간지, 남부고냉지 및 동해안 북부해안지에 적응하는 품종으로 보급하게 되었다. 보통기 재배에서 평균 출수기가 7 월 27일로 ‘오대’와 같은 조생종이다. 간장은 70 cm로 ‘오대’ 와 같고 수장은 19 cm로 ‘오대’보다 2 cm 작다. 주당 이삭수 와 이삭당 입수는 16개, 78개로 각각 ‘오대’보다 각각 3개, 2 개 많았다. 등숙비율은 88.8%로 ‘오대’보다 높으며, 현미천립 중이 21.7 g으로 중소립종이다. 불시출수율은 낮으나 수발아 율은 10.5%로 ‘오대’보다 높은 수준이었고, 내냉성 검정 결 과 출수지연일수가 7일로 ‘오대’보다 3일 짧았으며, 냉수구 임실률이 35%로 ‘오대’보다 낮았다. 재배포장에서의 도복은 ‘오대’와 비슷한 수준이었다. 도열병에는 강하나 흰잎마름병, 줄무늬잎마름병 및 해충에는 약하다. 쌀알은 심복백이 없이 맑고 투명하며, 단백질 함량이 6.6%로 높았지만 아밀로스 함 량이 18.8로 ‘오대’보다 밥이 부드러우며, 식미관능검정 결과 0.24로 ‘오대’와 비슷한 수준이었다. 제현율, 현백율, 도정률 은 ‘오대’와 비슷한 수준이었지만 도정된 쌀의 완전립률과 완 전미 도정수율이 각각 96.5, 73.1%로 ‘오대’보다 우수하였다. 수량성은 보통기 표준재배 5개소에서 평균 5.29 MT/ha로 ‘오대’보다 4% 증수되었다(등록번호: 제5570호).

저글루테린 및 저아밀로스 품종인 ‘건양2호’는 ‘중국173 호’와 ‘주남벼’를 각각 모본과 부본으로 인공교배 후 집단육 종법을 통하여 육성한 기능성 품종이다. ‘건양2호’의 출수기 는 영호남 및 중부평야지 보통기 보비재배에서 8월 10일로 ‘남평벼’보다 5일 빠른 중생종이다. 간장은 65 cm로 내도복 성이며, 불시출수와 수발아는 안되는 편이고 내냉성은 ‘남평 벼’와 비슷한 편이다. 잎도열병 밭못자리검정에서 중정도 저항성을 보였으며, 줄무늬잎마름병과 흰잎마름병(K1, K2, K3) 에는 저항성이다. ‘건양2호’의 아밀로스함량은 11.5%로 메벼 와 찹쌀의 중간형태로 불투명한 저아밀로스 품종이며, 단백질 함량은 6.0%로 ‘남평벼’보다 약간 낮으며 소화성 전분인 글 루테린 비율이 63.1%로 ‘남평벼’의 73.8%보다 낮다. ‘건양2 호’의 쌀 수량성은 4.61 MT/ha로 ‘남평벼’보다 9% 감수되었 고, 적응지역은 영호남 및 중부 평야 1모작지이다(품종 등록 번호: 제5105호).

In here, we screened drought tolerant varieties with modified leaf water loss rate assay and visual drought tolerant phenotype in the greenhouse conditions with more than 800 varieties. Among these varieties, Samgang, Gumei4 and Apo showed the lowest of leaf water loss rate and strong drought tolerant phenotype. To identify drought QTLs with Samgang variety, we developed the doubled-haploid (DH) population consist of 101 lines derived from a cross the drought tolerant cultivar Samgang and the drought sensitive cultivar Nagdong. To score the drought phenotype degrees of this population, we withheld water for 6 weeks and treated the watering for 7 days. After watering, visual phenotype was observed 1 to 9 degree according to the standard evaluation system for rice, IRRI. Drought sensitive parent Nagdong was almost died and was scored as 9 degree, while tolerant parent Samgang showed slightly leaf tip drying phenotype and was scored as 3 degree in our experimental conditions. Three main QTLs were detected on chromosome 2, 6, and 11 with this visual phenotype. We also measured relative water contend of these population under drought stress conditions, and got one main QTL on chromosome 11. The QTL loci on chromosome 11 with flanking markers RM26755-RM287 has a function for visual phenotype and relative water content under drought conditions.

Rice is a staple food crop for more than half of the world population. Severe losses of rice production was caused by various environmental conditions such as cold, heat and flooding annually. Rice is a highly sensitive to low temperature below 15-20 ℃ because of originating from tropical or subtropical climates. Especially, seedling of rice is easily damaged to low temperature and result in seedling yellowing, growth retardation, reduced tillering and yield losses at last. We used a recombinant inbreeding lines (RIL) population of 384 individuals derived from a cross between Hanareum 2, a highly cold sensitive variety and Unkwang, a cold tolerant variety for molecular mapping of QTLs related to cold tolerance. Seedling discoloration of each lines and parents caused by cold response were investigated in field condition after transplanting. And leaf samples of RIL population were collected for evaluation of chlorophyll content using 80% acetone extraction. The seedling of each lines and parents was subjected to low temperate by 5~13 ℃ during 14 days. The cold recovery score (CRS) of RILs was recorded after 4 days recovery period according to standard evaluation system (SES, IRRI). Total of eight QTLs were detected on chromosome 1, 7, 8, 10, 11 and 12 using cold tolerance traits, chlorophyll content, seedling discoloration and cold recovery score in 384 RILs. The qCRS12, which detected on chromosome 12 between two flanking markers id12002113, id12002563 (1.1 Mbp) showed 25 LOD score with 26% of phenotypic variation of cold recovery score in RILs population. The positive allele contributing to cold tolerance came from the cold tolerant parent Unkwang. The result may provide useful information for a marker-assisted breeding program to improve cold tolerant in rice.

A rice variety ‘Dabo‘ is a japonica rice (Oryza sativa L.) with good eating quality, lodging tolerance, and resistance to rice stripe virus (RSV) and blight bacterial disease(BB). It is developed by the rice breeding team of Yeongdeog Substation, National Institute Crop Science, RDA in 2012. This variety derived from a cross between ‘Yeongdeog31’ with good plant type and ‘Milyang165’ with good eating quality conducted in 2001/2002 winter season. A promising line, YR23160-31-2-1-5-B-3, selected by pedigree breeding method was designated as the name of ‘Yeongdeog53’ in 2009. After the local adaptability test was carried out at seven locations from 2010 to 2012, ‘Yeongdeog53’ was released as the name of ‘Dabo’ in 2012. ‘Dabo’ is short culm length as 69 cm and medium-growth duration. This variety is resistant to races, K1, K2, and K3 of bacterial blight and stripe virus and moderately resistant to leaf blast disease. ‘Dabo’ has translucent and clear milled rice kernel without white core and belly rice, and good eating quality as a result of panel test. The yield potential of ‘Dabo’ in milled rice is about 5.90 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to south plain, east-south costal area, and south mid-mountainous area.

Recently, concerns have been voiced about the high eating quality rice in the market. To cope the high quality demands in rice market, a rice cultivar ‘Jinsumi’ which is showing high grain quality and multi-resistant to diseases was developed by the National Institute of Crop Science, RDA, Miryang, Korea. ‘Jinsumi’ was derived from a three-way cross of ‘Milyang165’and F1 plant of YR16195-B-B-B-21-1/Milyang169. The pedigree of ‘Jinsumi’ was YR21999-B-B-B-17-3-1 and designated as ‘Milyang 218’ in 2005. Heading date of ‘Jinsumi’ was August 15 as mid-late maturing ecotype. ‘Jinsumi’ showed multi resistant to rice stripe virus (RSV), bacterial blight races of K1, K2, K3 and moderately resistant to leaf blast disease. The grain appearance of ‘Jinsumi’ was translucent and showed 96.6% of head rice ratio. The milled rice yield of ‘Jinsumi’ was 5.74 MT/ha at ordinary transplanting of local adaptability test. ‘Jinsumi’ would be adaptable to the plain area of Yeongnam province in Korea.

눈큰흑찰은 최근 국민의 건강에 대한 관심에 대한 요구에 부응하기 위해 2012년 국립식량과학원 기능성작물부에서 육 성한 품종이다. 눈큰흑찰은 씨눈에 함유된 기능성 물질 함량 이 높은 벼 개발을 목적으로 get를 모본으로 하고 흑찰벼인 조생흑찰 부본으로 교배하여 계통육종법으로 육성되었다. 선 발된 YR25277-B-B-314-2 계통을 밀양263호로 계통명을 부 여하고 2010～2012년 3년간 지역적응시험 실시하여 2012년 12월 농촌진흥청 농작물 직무육성 신품종선정위원회에서 품 종으로 선정되었으며 눈큰흑찰로 명명하였다. 눈큰흑찰의 출 수기는 전국 평균 7월 30일로 조생흑찰과 비슷한 조생종이다. 벼 키는 65 cm로 조생흑찰과 비슷하며 포기당 이삭수와 이삭 당 벼알수도 각각 13개와 73개로 조생흑찰과 비슷하다. 천랍 중이 17.8 g으로 조생흑찰보다 1.7 g 정도 가벼운 편이다. 도 복 및 도열병에는 강하나 흰잎마름병, 바이러스병 및 해충에 약한 편이다. 쌀수량은 3.54 Mt/ha로 조생흑찰의 4.12 MT/ha 보다 낮은 편이다. 현미모양은 장폭비 1.93으로 조생흑찰과 비슷한 중장립형이며 종피에 안토시아닌이 함유된 흑색찰벼 이다. 눈큰흑찰은 거대배 품종으로 씨눈무게가 1.46 mg으로 조생흑찰 보다 3배 정도 무거우며, 이에 따라 씨눈에 많이 포 함된 GABA 함량이 높다. 눈큰흑찰의 적응지역은 중부 및 남 부 평야지이다.

유색 수수인 황금찰수수를 도정할 때 grain과 함께 발생 하는 도정부산물인 hull과 bran의 4가지 용매 추출물의 총 폴리페놀 함량, 항산화 활성, 천연색소 함량과 RAW 264.7 세포주를 이용하여 항염증 활성을 검정하였으며 결과를 요 약하면 아래와 같다. 1. 도정부산물인 hull의 100% 메탄올과 70% 에탄올 추 출물에서 총 폴리페놀 함량이 29.4±0.4와 29.7±0.2 mg GAE/100 g으로 가장 많았고, ABTS 라디컬 소거능(IC50) 이 6.8±0.4, 6.3±0.1 μg/mL로 가장 높은 항산화 활성 을 나타내었다. 2. 총 천연색소 함량에서도 수수 hull의 0.5% 염산 함유 100% 메탄올 추출물에서 322.6±14.5 mg/100g으로 가 장 많은 색소 함량을 나타내었고 hull, bran, grain 모 두의 경우에서 0.5% 염산을 함유한 100% 메탄올을 용매로 추출한 경우에서 가장 많아 수수를 이용하여 천연색소를 추출할 경우 수수 부산물인 hull을 산을 함 유한 메탄올로 추출하였을 때 가장 많은 색소 추출물 을 얻을 수 있었다. 3. 수수 도정부산물과 grain 추출물을 LPS로 NO 생성을 유도한 RAW 264.7 세포에 처리하였을 때, 세포 독성 이 없는 100 ug/mL 농도 이하에서의 NO 생성 억제량 은 hull, bran, grain 추출물의 순으로 나타났고 hull 추 출물의 경우에 농도에 따라 가장 큰 NO 생성 억제를 보였으며 천연색소 화합물 중에서는 apigeninidin의 NO 생성 억제 활성을 확인하였다. 4. 위 결과를 종합해 볼 때, 수수 도정부산물 중 hull은 grain 에 비해 총 폴리페놀 화합물과 천연색소 함량이 높고 항산화 활성과 RAW 264.7 대식세포에서의 NO 생성 량 억제 활성이 우수하여 앞으로 수수 부산물이 항산 화 및 항염증 소재로 가능성이 있음을 확인하였다.

‘산호미’는 국립식량과학원 상주출장소에서 중산간지 재배에 알맞은 복합내병성 고품질 벼를 육성하고자, 2002년 하계에 상미벼를 모본으로 하고, 상주24호와 화영벼의 F1 개체를 부본으로 인공교배 하였다. F3 세대 이후에는 계통육종법으로 전개하였으며, 주요 농업형질 조사, 병해충 저항성 및 미질특성의 조사를 실시하였고, 2009～2010년 생산력검정을 실시하여 복합내병성을 갖춘 YR24337-53-3-18-3-3 계통을 선발하였으며 상주44호로 계통명을 부여하였다. 2010～2012년 지역적응성시험을 실시한 결과 대조품종인 오대벼에 비해 도열병, 흰잎마름병, 줄무늬잎마름병에 강하며 외관품위가 매우 우수하여, 2012년 농작물 직무육성 신품종-선정심의회에서 신품종으로 선정하여 ‘산호미’라 명명하였고, 북부평야지, 중산간지 및 남부고냉지에 적응하는 품종으로 보급하게 되었다. 출수기는 7월 26일로 오대벼 보다 2일 빠르며, 간장과 수장은 오대벼보다 1 cm 작고 주당수수는 14개, 수당립수는 82개로 오대벼와 비슷하다. 등숙비율은 85.4%로 오대벼보다 높으며, 현미천립중이 21.1 g으로 중소립종이다. 유묘내냉성은 오대벼와 비슷하고 출수지연일수가 8일로 오대벼에 비해 짧으나, 임실률이 39%로 낮은 편이다. 도열병, 흰잎마름병(K1～K3)과 줄무늬잎마름병에는 저항성이나 오갈병 및 검은줄 오갈병에는 약하다. 쌀알은 심복백이 없이 맑고 투명하며 아밀로스 함량은 오대벼와 비슷하며, 단백질 함량은 6.7%로 약간 높고 밥맛은 매우 양호하다. 오대벼에 비해 도정률은 낮은편이나, 완전미 도정수율이67.3%로 오대벼보다 높다. 수량성은 6개소에서 보통기 표준재배시 4.99 MT/ha 로 오대벼보다 2% 낮았다.

거대쌀눈의 특성과 검정쌀 그리고 찹쌀의 특성을 보유한 눈큰흑찰의 침종과 발아 그리고 기질로 글루탐산을 처리하 였을 경우의 가바를 포함한 주요 성분의 분석 결과는 다음 과 같다. 1. 싹 발아 길이를 기준으로 눈큰흑찰의 가바 함량은 싹 길이가 5~10 mm인 stage-3에 93.9 mg/100 g으로 최 고를 보였고, 대량 제조 조건에서는 최고 126.9 mg의 가바를 함유하고 있음을 확인하였다. 2. 침종에 의한 성분 분석에서는 72시간 침종에서 폴리 페놀, 플라보노이드, 아미노산 그리고 가바 함량이 가 장 많이 축적됨을 확인하였다. 3. 글루탐산 탈탄산효소의 작용에 의한 가바 함량 증가는 현미와 쌀겨 모두에서 급격한 증가가 관찰되었고, 눈 큰흑찰 현미와 쌀겨의 경우 가바 함량이 각각 354.6 mg/100 g과 726.4 mg으로 현미와 쌀겨에 비해 각각 14배와 3배 함량이 증가하였다. 따라서 본 연구에서 눈큰흑찰의 발아와 침종에 따른 품질 특성을 분석한 결과, 뇌의 대사전달 물질의 조정 작용과 고 혈압 그리고 스트레스 조정 기능이 있는 가바의 함량이 침 종과 발아에 의해 일반 쌀에 비해 급격히 증가함을 확인하 였다. 특히나 글루탐산탈탄산 효소의 작용에 의한 눈큰흑찰 의 현미와 쌀겨의 가바 생성은 현재까지 보고된 그 어떤 쌀 품종에서 분석된 가바 함량보다도 가장 우수함을 확인할 수 있어 향후 기능성 발아현미 가공을 위한 원료로 활용이 가 능하며, 침종 조건은 가바 함량이 증진된 밥의 제조에 활용 이 가능하고, 일본에서 시판되는 가바 건강식품의 용량과 맞먹는 함량을 지닌 눈큰흑찰을 이용한 가바쌀 생산과 가바 의 효능에 의한 혈압강하, 체중조절, 알코올 관련 질환 등에 효능이 있는 건강기능성 식품 원료로 활용이 가능할 것으로 사료된다.

Even rice is one of the most important food crops in the world, its micronutrient contents including iron is not enough to solve mineral malnutrition which is a significant public health issue in most developing countries. Iron deficiency is probably the most widespread micronutrient deficiency in humans. Experts estimate that a rice based diet should contain 14.5 ppm iron in endosperm. However, Cesar P et al reported that average iron content in milled rice was 2 ~ 3 ppm, whease it was 10 ~ 11 ppm in brown rice. Fe content of rice is usually measured by inductively plasma spectrometry (ICP). It takes times and could make error while sample processing. To breed high iron contained rice variety, the effective screen method for select high iron contained elite line is essential. To develop more effective method in screening high Fe contained brown rice, we investigate the relation the leaf chlorophyll content with iron content in brown rice. Result of analyzing leaf chlorophyll content of OsNAS3-OX which contain more Fe than wild-type plant after cultivated on Fe limited MS medium, those of OsNAS3-OX was higher than those of wild-type plant in 0 and 20 % Fe contained MS medium. After measured Fe content in twenty kinds of brown rice, we cultivated those in Fe limited MS medium then investigate the relation of leaf chlorophyll content with Fe content of brown rice. In 0 and 5 % Fe contained MS medium, the leaf chlorophyll content was highly related with Fe content of brown rice as 0.66 and 0.79. Though these result, analyze of leaf chlorophyll content cultivated in 5 % Fe content in MS media was effect on screening high Fe contained.

The global rice reduction due to drought averages 18 Mt, especially, 23 Mha of rice fields in Asia are drought-prone. However, rice breeding programs focusing on drought resistance have made little progress to date. Because proper screening approaches with large scale were not developed to evaluate the drought tolerant degree. In here, we have developed of leaf water loss rate with plastic ware in dark conditions for large screening. Through this bioassay system, we examined drought phenotype degrees of 650 rice varieties. To validate whether this optimized bioassay system is corelated with drought phenotype, we chose 14 varieties having the lowest or highest of the water loss rate. We observed the visual drought phenotype and agricultural traits in green house and field conditions. Apo and Samgang having the lowest of leaf water loss rate showed drought tolerance phenotype, whereas Yeolbaeg and Milyang254 having the highest of leaf water loss rate showed drought sensitive phenotype. Apo displayed proper root length trait and Samgang showed good root dry trait in the greenhouse conditions. These results suggest that a simple screening procedure with water lose rate of leaves is effective to perform large scale screening for drought phenotype in rice.

Drought is a one of the most serious abiotic stresses limiting rice production. However, little progress has been made in the genetic analysis of drought tolerance, because it is a complex trait controlled by a number of genes and affected by various environmental factors. The most efficient method for drought tolerance breeding is using drought tolerance genetic resources. We used a doubled-haploid (DH) population consist of 101 lines derived from a cross the drought tolerant cultivar ‘Samgang’ and the drought sensitive cultivar ‘Nagdong’ for QTL analysis. Drought stress was treated by withholding water for 6 weeks, and then rewatered for 7 days. After rewatering visual phenotype was observed according to the standard evaluation system for rice, IRRI. Drought sensitive parent ‘Nagdong’ was almost died, while tolerant parent ‘Samgang’ showed slightly leaf tip dring phenotype. The qdr11 detected on chromosome 11 with flanking markers RM26755-RM287 and accounted for 19% phenotype variation with a LOD score of 3.7.

Green rice leafhopper(GRH), Nephotettix cincticeps Uhier, is one of the major insect pests of rice (Oryza sativa L.) in the temperate growing region of East Asia. GRH sucks sap from both xylem and phoem of susceptible rice varieties, and increased GRH populations cause sooty mold disease on the ears of rice after heading stage. In addition to direct plant destruction, GRH also causes damage to rice plants by transmitting rice dwarf viruses causing rice dwarf viruses disease which could decrease the yield of rice. Development of GRH resistant rice varieties for reducing yield loss is an important objective in current breeding programs. In this study, we developed three SSR markers(RM18166, RM516, RM18171) and one Indel marker(Indel15040) which could select Grh1-resistant varieties using population derived from cross lines between Grh1-resistant variety ‘Singwang’ which contains Grh1 gene and susceptible variety ‘Ilpum’. PCR products of RM18166 which was one of the developed markers were easily detected in agarose gel. These markers will be useful for development of the Grh1-resistant varieties through marker-assisted selection(MAS) without bio-examination in rice breeding

Bakanae disease is one of the most serious and oldest problems of rice production, which was first described in 1828 in Japan (Ito and Kimura 1931). This disease may infect rice plants from the pre-emergence stage to the mature stage, with severe infection of rice seeds resulting poor germination or withering (Iqbal et al. 2011). Under favorable environmental conditions, infected plants have the capacity to produce numerous conidia that subsequently infect proximate healthy plants, resulting in major yield loss (Ou 1985). One hundred sixty nine NILs, YR28297 (BC6F4) generated by five backcrosses of Shingwang with the genetic background of susceptible japonica variety, Ilpum were used for QTL analysis. Rice bakanae disease pathogen, CF283, was mainly used in this study and inoculation and evaluation of bakanae disease was performed with the method of the large-scale screening method developed by Kim et al. (2014). A major QTL for resistance against bakanae disease on chromosome 1 was identified using SSR marker, RM9, which explaining 65 % of the total phenotype variation. The major QTL designated as qBK1 and mapped to a 4.4 Mbp region between RM24 (19.30 Mb) and RM11295 (23.72 Mb). The results of this study are expected to provide useful information toward developing resistant rice lines to this detrimental fungal disease.