‘동보’는 국립식량과학원 영덕출장소에서 1996년 하계에 밥맛이 뛰어나면서 재배 안정성이 높은 벼 품종을 육성할 목적으로 내풍성이면서 각종 병해에 강한 영덕19호를 모본으로밥맛이 우수한 ‘고시히카리’를 부본으로 인공교배를 실시하고, 1996/1997 동계에 24개체의 F1 식물체를 양성하여 YR18320의 교배번호를 부여하였다. 1997년 하계포장에 F2 집단 전개 후 선발하여 1998년 하계에 F3세대 51계통을 육성하고, 이후 F4～F8세대를 계통육종법으로 전개하여 내도복성이면서 풍해에 강하고 병해에 안정적인 저항성을 나타내는 계통을 선발하여 2006년 생산력검정예비시험, 2007년 생산력검정본시험을 실시한 후 완전미율이 높고 식미가 우수하면서재배 안정성이 높은 YR18320-21-1-1-2-2-2을 선발하여 ‘영덕49호’로 명명하였다. 2008년부터 2010년까지 3년간 지역적응시험을 실시한 결과 중생종이면서 쌀 품위가 좋고 밥맛이 양호하며 내풍성과 내병성에 양호한 것으로 평가되어2010년 12월 농작물 직무육성 신품종 선정위원회에서 국가품종목록으로 등재 할 것을 결정하고 ‘동보’로 명명하여 적응지역인 동남부해안지, 중부평야 및 남부중산간지에 보급하게되었다. ‘동보’의 출수기는 보통기 재배에서 평균 8월 13일로‘화성벼’보다 1일 늦은 중생종 품종이다. 직립 초형이고 탈립은 잘되지 않고 이삭추출은 양호 하고 까락이 거의 없다. 수당립수는 ‘화성벼’보다 약간 많은 편이고 현미천립중은 23.6g으로 ‘화성벼’보다 더 무겁다. 도정특성과 완전미률은 ‘화성벼’보다 약간 좋은 편이고 외관특성이 맑고 투명하며 밥맛은‘화성벼’보다 우수하다. 불시출수는 안되는 편이나 수발아는‘화성벼’보다 더 잘되고, 위조현상에 강하고 성숙기 엽노화가느린 편이며 내냉성은 ‘화성벼’와 같은 수준이다. 잎도열병밭못자리 검정 결과 중도저항성을 보였고 줄무늬잎마름병과흰잎마름병(K1, K2, K3)에는 강하나 오갈병 및 검은줄오갈병에 약하고 벼멸구 등 충해에는 감수성이다. ‘동보’의 수량성은 ’08～’10년 3개년간 실시한 지역적응시험 보통기 보비재배 4개소에서 5.71 MT/ha로 ‘화성벼’ 대비 3% 증수되었으며, 이모작재배에서는 4.79 MT/ha ‘남평벼’ 대비 4% 감수되었고, 만식재배에서는 4.75 MT/ha로 ‘남평벼’와 같았다. ‘동보’의 적응지역은 동해안냉조풍지, 중부평야지 및 남부중산간지이다.

‘영호진미’는 쌀의 외관과 밥맛이 양호한 고품질 벼를 육성하고자 ‘03/'04 동계에 밥맛이 우수한 양질미 히또메보레와단간이면서 내병성이 양호한 주남벼를 부본으로 인공교배하여 육성하였다. 그후에는 조기에 고정된 계통을 얻고자 약배양을 실시하였으며, YR24733Acp10 계통을 선발하여 밀양228호의 계통명을 부여하였다. 07~’09년 3개년간 지역적응시험결과 우수성이 인정되어 농작물 직무육성 신품종 선정위원회에서 국가목록 등재 품종으로 선정되었다. ‘영호진미’는 영남평야 1모작지에 적응성이 높은 중만생 고품질 벼 품종이다.‘영호진미’의 출수기는 남부평야지와 남부 및 서남부해안지보통기재배에서 8월 21일로 ‘남평벼’보다 5일 늦은 중만생종품종이다. 간장과 수당립수는 ‘남평벼’보다 적은 편이고 현미천립중은 ‘남평벼’보다 약간 무거운 편이다. 도정특성은 ‘남평벼’와 비슷한 편이고 단백질함량은 ‘남평벼’보다 낮고 밥맛은 양호한 편이다. 불시출수는 없으며, 수발아는 ‘남평벼’와비슷하였으며, 내냉성은 중정도이고 냉수구 출수지연일수가긴 편이다. 잎도열병 밭못자리 검정 결과 약한 반응을 보였고,흰잎마름병에는 레이스 K1, K2, K3에는 저항성이지만 K3a에는 이병성이다. 줄무늬잎마름병에는 저항성이지만 오갈병과검은줄오갈병에는 약하고 벼멸구 등 해충에도 약하다. ‘영호진미’는 영호남 평야지 1모작 적응 품종으로, 수량성은 2007년부터 2009년까지 3년간 실시한 지역적응시험 결과 남부 및남서 해안지와 호남평야지, 영남평야지의 보통기 보비재배 10개소에서 5.44 MT/ha로 ‘남평벼’보다 3% 감수되었다.

국내 주요 해충인 끝동매미충에 대한 저항성 품종‘청남’은 ‘기누히까리’와 ‘밀양189호’를 각각 모본과 부본으로 인공교배 한 후 약배양으로 육성하였으며, 주요 연구결과는 아래와 같다. 출수기는 평야지 보통기 재배에서 8월 11일로 중생종이며 수당립수는 ‘남평벼’보다 적은 편이고 현미천립중은 무거운 편이다. 불시출수는 발생하지 않았으며, 수발아는 ‘남평벼’보다 약간 높은 편이고, 포장도복은 없었으며, 내냉성은 ‘남평벼’와 비슷하다. 잎도열병 밭못자리 검정 중 정도 저항성을 보였으며, 줄무늬잎마름병과 흰잎마름병(K1, K2, K3)에는 강하며, 바이러스병을 매개하는 끝동매미충에 저항성으로 오갈병에 포장저항성을 나타낸다. 검은줄오갈병에 약하고 벼멸구 등 충해에는 감수성이다. ‘청남’의 끝동매미충 유전분석을 수행한 결과 1개의 단순우성유전자에 의해 지배됨을 확인하였다. ‘청남’의 쌀은 맑고 투명하며 완전미율이 높았으며, 밥맛은 양호한 편이다. ‘청남’의 수량성은 2007년부터 2009년까지 3년간 실시한 지역적응시험 보통기 보비재배 11개소에서 5.43 MT/ha, 이모작재배에서는 5.00 MT/ha, 만식재배에서는 5.18 MT/ha이었다.

고령화 사회로 접어들면서 만성 신부전증 환자는 증가되고 있으며, 저단백질 식품에 대한 수요도 증가되고 있다. 중국173/주남벼 재조합 집단을 이용하여 저Glutelin 고품질 벼 품종개발의 육종효율 증진을 위해 DNA마커의 이용성을 검토하였으며, 밥맛향상을 위해 미질관련 형질들과 상관분석을 수행하였다. 중국173호/주남벼 재조합 집단에서 SDS PAGE결과 얻어진 저Glutelin 표현형과 functional DNA marker의 유전자형이 일치하여 DNA marker를 이용한 선발이 가능함을 확인하였다. 밥맛향상을 위해 미질관련 형질들과 상관분석을 수행한 결과, 윤기값과 Amylose 함량은 유의한 부의 상관을 나타내었으며, 단백질 함량은 윤기값에 많은 영향을 미치지 않았다. 반면, 단백질 조성에 따른 저Glutelin 계통군과 정상계통군의 비교에서 저Glutelin 계통군은 정상군에 비해 유의하게 윤기값이 낮았으며, 저Glutelin-저Amylose 계통군과 정상계통군은 대등한 윤기값을 유지하였다. 따라서 고품질 저Glutelin 품종개발을 위해 저Amylose 유전자의 활용이 바람직한 것으로 판단되었다. 이들 분석결과와 주요 농업적 특성을 고려하여 저Glutelin-저Amylose인 유망계통 밀양262호를 육성하였으며, 금후 고품질 저Glutelin 품종개발에 활용될 것으로 기대된다.

Rice is a staple food for more than 50% of the world's population. Embryo comprises only 2 to 3% of the weight distribution of the entire pericarp but has higher concentration of vitamins, proteins, and essential fatty acids than the other parts of grains. Moreover, α-tocoperol, γ-oryzanol, phytic acid and γ-aminobutric acid that have nutraceutical value are abundant. Increasing the volume of embryo assures the fortification of nutritional value of rice grain. We developed new black waxy giant embryo rice, Milyang 263 by crossing Josaengheugchal, a black waxy rice variety, and get, a giant embryo mutant generated by tissue culture. The nutrient contents and physical properties of Milyang 263 were compared with several giant embryo mutants and normal embryo rice varieties. Changes in the nutrient properties after germination were also observed. Results indicated that this new black waxy giant embryo rice, Milyang 263, offers a promising source for improving nutritional quality of rice especially anthocyanin, essential minerals, and GABA.

‘만미벼’는 작물과학원 영남농업연구소(현 국립식량과학원 기능성작물부)에서 2002년도에 육성한 중만생 저아밀로스 반찹쌀 품종으로 주요특성과 수량성을 요약하면 다음과 같다. 1. 출수기는 남부평야지의 보통기재배에서 8월 16일로 ‘동진벼’ 보다 2일 빠른 중만생종이다. 2. 수당립수는 ‘동진벼’ 보다 18개 많으나, 현미천립중은 19.9 g으로 ‘동진벼’ 보다 가벼운 편이며 등숙비율이 약간 떨어진다. 3. 위조현상에 강하고 성숙기 엽노화가 느린 편이며 내

Field experiments were conducted to investigate persistence of Chinese milk vetch(CMV) seed under naturally reseeded CMV-rice cropping systems during the period of 2007～2009. Persistence of the CMV seeds were evaluated in the naturally reseeded CMV-rice field on different tillage methods and soil depths based on the seed number recovered and the seed longevity in soil. Field observation in the naturally reseeded CMV rice field showed that as many as 917～2,185 CMV seeds m-2 were found from 0～15cm soil depth in the rotary tillage and 250～10,105 CMV seeds in minimum tillage rice cultivation in autumn. The recovered seed germinated 25～33%, 23～43% but still had high percentage of hard seed having 64～72% and 51～77%. Field experiment showed that the CMV seedling still emerged even after 2 years of continuous destructive killing of emerged CMV plant by rotary tillage in naturally reseeded CMV-rice field, indicating that CMV seeds persistent at least two years in rice field.

Experiments were conducted to investigated the change of primary dormancy and viability of Chinese milk vetch(CMV) seed buried in soil both as seed and pod with seeds under CMV-rice cropping system during the period of 2007～2009. The freshly harvested CMV seed alone and pods with seeds were buried in rice field at 0, 5 and 10cm depths and determined change of seed dormancy and viability at one to three month intervals for 10 months. The CMV seed had high dormancy of 95%, showing only 4～5% germination at the beginning in June but the seed dormancy was gradually broken at rice harvest time in autumn, showing 25 to 35% for seed and 55 to 61% for pod with seeds. The viability loss was faster in the seed than in the pod with seeds regardless of depths of placement in the soil base on decayed seeds. Also the seed placed on the soil surface lost viability faster than the 5～10 burial depths. However, appreciable number of CMV seeds still remained at even 4 months after burial in soil. These results indicate that seed dormancy was enable CMV plant to regenerate naturally from the remained soil seed bank at rice harvest time in autumn.

‘oamibyeo’ a mid-late maturing ecotype with high amylose content in kernels, was developed by the rice breeding team of National Yeongnam Agricultural Experiment Station(NYAES) in 2000 and released in 2001. This variety was derived from the three way cross of Milyang 95//Kimcheonaengmi/2*Ilpumbyeo (in 1992 summer) through the pedigree breeding method and designated as ‘ilyang 168’in 1997. The heading date of ‘oamibyeo’was Aug. 18 in ordinary season with culm length of 85 cm. However, ‘oamibyeo’showed susceptible to bacterial leaf blight, stripe virus and leaf blast disease. The amylose content of ‘oamibyeo’in milled rice kernels is about 26.7% with translucent and clear in chalkness. Thus, ‘oamibyeo’is expected to be used as a source grain for rice noodle industries. The milled rice yield potential of ‘oamibyeo’is about 5.38 MT/ha in local adaptability test of three years and it would be adaptable to Yeongnam plain of Korea.

Rice blast resistance is considered one of the most important traits in rice breeding and the disease, caused by Magnaporthe grisea Barr, has brought significant crop losses annually. Moreover, breakdown of resistance normally occurs in two to five years after cultivar release, thus a more durable resistance is needed for better control of this disease. We developed a new variety, Keumo3, which showed strong resistance to leaf blast. It was tested in 2003 to 2007 at fourteen blast nursery sites covering entire rice-growing regions of South Korea. It showed resistance reactions in 12 regions and moderate in 2 regions without showing susceptible reactions. Durability test by sequential planting method indicated that this variety had better resistance. Results showed that Keumo3 was incompatible against 19 blast isolates with the exception of KI101 by artificial inoculation. To understand the genetic control of blast resistance in rice cultivar Keumo3 and facilitate its utilization, recombinant inbred lines (RIL) consisting of 290 F5 lines derived from Akidagomachi/Keumo3 were analyzed and genotyped with Pizt InDel marker zt56591. The recombination value between the marker allele of zt56591 and bioassay data of blast nursery test was 1.1%. These results indicated that MAS can be applied in selecting breeding populations for blast resistance using zt56591 as DNA marker.

Many important traits have been tagged allowing plant breeders to apply marker assisted selection (MAS) in rice. PCR itself is simple to set up, and requires little hands-on time. However, a crucial limiting step of MAS programs is the reliable and efficient extraction of DNA which can be performed on thousands of individuals. In this study, We describe a modification of the DNA extraction method, in which cetyltrimethylammonium bromide (CTAB) is used to extract DNA from leaf tissues for suitable MAS in rice. We followed the standard 2% CTAB extraction method in all the procedure. In addition we used the 1.2 ml 8-strip tube instead of 1.5 ml E-tubes to fit the 8-multichannel pipette and employ the 96 well plate to use the swing bucket centrifuge. Our modified CTAB DNA extraction method offers several advantages with respect to traditional and simple methods. 1) adult leaf samples collected in paddy field are applicable. 2) 96 leaf samples can be homogenized only one-time by using tungsten carbonate bead and 96well block. 3) semiautomatic loading method using 8-multichannel pipette from DNA extraction to electrophoresis of PCR products. 4) our system can extract about 400 leaf samples per day by only one technicion. Therefore, this method could be useful for marker assisted breeding in rice.

In rice, tillering is an important trait determining yield. To study tillering at the agricultural and molecular aspects, we have examined a spontaneous rice mutant that showed reduction in the number of culms. The mutant was derived from a F6 line of the cross of Junambyeo*4 / IR72. It could produce, on average, 4 tillers per hill in the paddy field while wild-type plants usually have 15. Except the reduced culm numbers, they also show pale green phenotypes. The phenotypes of this mutant were co-segregated as the monogenic Mendelian ratio (χ2 = 0.002, p = 0.969). In order to locate a gene responsible for the rcn phenotype, the mutant with the japonica genetic background was crossed with Milyang21 of the indica background. Bulked segregant analysis was used for rapid determination of chromosomal location. Three SSR markers (RM551, RM8213, and RM16467) on chromosome 4 were genetically associated with the mutant phenotype. Each of the 217 F2 plants was genotyped with simple sequence length polymorphisms. The data showed that RM16572 on chromosome 4 was the closest marker that showed perfect co-segregation among the F2 population. We suggest the new rcn gene studied here name as rcn10t because there was no report which exhibit a rcn phenotype with a pleiotropic effect of pale green (chlorophyll deficiency), and mapped at same position on chromosome 4.

Lodging is classified as root lodging caused by the loss of supporting force in the root, bending caused by the deformation of the stem and breaking where the stem breaks down as loads exceeding critical elasticity were applied. This research excluded breaking which is not in a state of equilibrium and tried to partition the level of lodging using an algebraic model in root lodging and stem lodging, or bending. When a vertical load was applied, the deformation of the stem of rice plant showed the form of a quadratic equation. The trace of the panicle neck in the process of lodging was an ellipse-shape. When loading was pure root lodging, the trace of the panicle neck became a circle of which culm length is the radius. When it was a pure stem lodging, the trace of the panicle neck is an ellipse of which major axis is culm length and minor axis is 0.64* culm length. When both stem lodging and root lodging occurred in a natural setting, the partitioning of lodging can be calculated by a formula using eccentricity of an ellipse, S=e*100/0.768(S is the ratio of stem lodging in the whole lodging, e is eccentricity of the ellipse). This method is expected to be useful in simple lodging partitioning. We could also calculate the partitioning of stem lodging and root lodging as units of angles as an accuracy method, by using a straight line calculated by differentiating a quadratic equation of stem deformation at the origin of the coordinates. These two methods for dividing root and stem lodging showed different values. However, each of them showed almost same values with different lodging degree in one plant.

This study was carried out to map Bphl and bph2 gene in Mudgo and Sangju13 (Oryza sativa L.) respectively conferring resistance to brown plan-thopper (BPH) and to establish the marker-assisted selection (MAS) system. Bulked seedling (grown for 20 days) test was conducted with the 73 F4 lines derived from a cross between Nagdongbyeo and Mudgo for Bphl and with 53 BC3F5 lines derived from the Milyang95/Sangju13 cross for bph2. Bph1 was mapped between RG413 and RG901 on chromo-some 12 at a distance of 7.5 cM from RG413 and 8.4 cM from RG90l. A recessive gene bph2 was located near RZ76 on chromosome 12 at a distance of 14.4 cM. Bphl and bph2 were linked to each other with a distance of about 30 cM. An RFLP marker, RG413 linked to Bphl, was converted to an STS marker to facilitate the marker-assisted selection. BPH resistant genotypes could be selected with 92% accuracy in a population derived from a line of NM47-B-B.