1) 수도 도열병에 저항성이었던 관옥 품종이 1969년에 와서 저항성이 역전된 원인을 분석하였다. 2) 경기도지방 16개 지역의 이병된 관옥품종에서 분리한 균주는 15개의 C계통 레이스와 1개의 N계통 레이스로 판정되었다. C계통 레이스 중에는 C-8이 9균주, C-7과 C-1이 각각 2균주, 그 나머지는 C-1과 유사한 것이 1균주이고 C-5와 유사한 것이 1균주였다. 3) 도열병에 대하여 고도로 저항성이었던 관옥품종은 중국계통의 벼를 침해 한 수 있는 C레이스의 만연에 기인되었다고 결론지을 수 있다.

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

‘안미’는 농촌진흥청 국립식량과학원과 국제미작연구소 간의 협력으로 분자육종법을 이용하여 2010년에 육성한 중만생 고품질 복합내병충성 품종이다. 지역적응시험을 3개년(2008~2010)간 수행한 결과, ‘안미’는 중부평야지에서 보통기 보비재배 시 출수기는 8월 15일로 ‘화성’보다 5일 늦은 중만생종으로 쌀수량은 보통기 표준재배에서 5.76 MT/ha로 ‘화성’보다 11% 증수되었다. ‘안미’는 ‘화성’에 비해 간장(77 cm)은 작고 수당립수는 많으나 등숙비율은 다소 낮았다. ‘안미’는 현미 장폭비가 1.84인 단원형이며 백미는 심복백 발현이 거의 없어 맑고 투명하다. ‘안미’의 알카리 붕괴도와 단백질 함량은 ‘화성’과 비슷하고 아밀로스 함량은 조금 낮았반면, 식미평가에서 밥맛은 매우 양호하였다. ‘안미’의 재배시험 과정 중 위조현상은 관찰되지 않았으며 성숙기 하위엽 노화는 늦은 편이었다. ‘안미’는 ‘화성’에 비해 수발아에 둔감하였고 내랭성 평가 중 적고는 나타나지 않았으나 임실율은 다소 낮았다. ‘안미’는 도열병, 벼흰잎마름병(K₁, K₂, K₃), 줄무늬잎마름병 및 벼멸구에 강한 저항성을 발현하였다.

‘설백’은 조숙 내병 고품질 중간찰 계통을 육성할 목적으로 2000년 하계에 중간찰 품종인 수원460호에 조숙 내병 고품질 품종인 그루벼를 인공교배하여 2010년 육성된 조생 내도복 뽀얀 중간찰이다. ‘설백’은 보통기 보비재배에서 출수기는 평균 7월 29일로 ‘오대벼’보다 3일 빠른 조생종이다. ‘설백’의 간장은 60 cm이며, 주당수수는 13개, 수당립수는 81개이고, 천립중은 20.7 g으로 오대벼보다 가볍다. ‘설백’의 아밀로스함량은 10.0%로 중간찰이고 쌀 외관은 투명도가 5로 불투명해 보인다. ‘설백’은 위조에 강하고 불시출수가 잘 되지 않으며 성숙기에 하엽 노화가 느린 편이다. ‘설백’은 수발아에 강한 편이고, 내냉성은 ‘오대벼’와 비슷한 수준이다. 잎도열병에는 강한 저항성이고 흰잎마름병, 바이러스병 및 해충에는 약하다. 지역적응시험 보통기 보비재배에서 평균 쌀 수량이 4.96 MT/ha로 ‘오대벼’ 대비 92%의 수량성을 보였다. 재배적지는 중부평야지, 북부평야지, 중산간지, 남부고랭지 및 동북부해안지이다.

‘월백’은 조숙 내병 고품질 중간찰 계통을 육성할 목적으로 2000년 하계에 중간찰 품종인 ‘Milkyqueen’에 조숙 내병 고품질 품종인 ‘그루벼’를 인공교배하여 2010년 육성된 조생 내도복 반투명 중간찰 품종으로 주요 특성을 요약하면 다음과 같다. ‘월백’의 보통기 보비재배에서 출수기는 평균 7월 31일로 ‘오대벼’보다 1일 늦은 조생종이다. ‘월백’의 간장은 67 cm이며, 주당수수는 16개, 수당립수는 59개이고, 현미천립중은 21.4 g 으로 ‘오대벼’보다 가볍다. ‘월백’의 아밀로스함량은 11.6%로 중간찰이고 쌀 외관은 투명도가 4로 반투명해 보인다. ‘월백’은 위조에 강하고 불시출수가 잘 되지 않으며 성숙기에 하엽 노화가 느린 편이다. ‘월백’은 수발아에 강한 편이고, 내랭성은 ‘오대벼’와 비슷한 수준이다. ‘월백’은 잎도열병에는 강한 저항성이고 흰잎마름병, 바이러스병 및 해충에는 약하다. 지역적응시험 보통기 보비재배에서 평균 쌀 수량이 5.13 MT/ha로 ‘오대벼’ 대비 95%의 수량성을 보였다. ‘월백’의 재배적지는 북부평야지, 중산간지, 남부고랭지 및 동북부해안지이다.

BPH(Brown planthopper, Nilaparvata lugens Stål) is a major insect of rice and give a lot of damages around Korea, Japan and East-West Asia. BPH often causes heavy losses of up to 60% of rice crop yields in susceptible cultivars. Especially, increase of the environmental friendly cultivation in South Korea has caused the outbreak of BPH rapidly. But few resistant varieties in Korea have known until now. Utilization of R genes in breeding programs has been the most effective and economical strategy for controlling insect resistance. It is reported that Bph1 gene is located on a long side of chromosome 12 and linked to bph2 among reported 18 R genes. BPH resistant "Iksan529" was derived from a cross between HR22538-GHB-36-4(bph2) and Iksan471 at Department of Rice and Winter Cereal Crop, NICS, RDA. Culm length of Iksan529 is 74cm and it shows moderate resistance to blast, and wide spectrum resistance to bacterial blight pathogen(K1, K2, K3) and stripe virus. Especially, Iksan529 was identified bph2 gene using KPM2(co-dominant CAPS marker) and KPM4(resistant-associated marker). When Iksan529 seedling were infested at 2nd and 3rd instar stages of BPH nymphs(Bio-type 1), it showed resistance at one month after infest. Iksan529 will be tested local adaptability for 3 years and deveoped for environmental friendly cultivation.

‘'Hwangkeumnuri’' is a japonica rice variety developed and registered by the rice breeding team of Honam Agricultural Research Institute, NICS, RDA in 2006. This variety was derived from a cross between ‘'Milyang 165’' (Junambyeo) with good quality and high yield and HR14732-B-67-2-3 with multi-disease resistance. This variety has about 125 days growth duration from transplanting to harvesting in west-southern coast, Honam and Youngnam plain of Korea. It is about 76 cm in culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows resistance to blast, bacterial blight pathogen from K1 to K3 and stripe virus, but susceptible to other major diseases and insect pests. The milled rice of ‘'Hwangkeumnuri’' exhibits translucent, relatively clear non-glutinous endosperm and midium short grain. It has similar amylose content of 18.9% and lower protein content of 6.2%, and good palatability of cooked rice compared with ‘'Nampyeongbyeo’'. The milled rice yield performance of this variety is about 5.74 MT/ha in local adaptability test for three years. ‘'Hwangkeumnuri’' would be adaptable to west-southern coast, Honam and Yeongnam plain of Korea.

"Geumanbyeo" is a new japonica rice variety developed by the rice breeding team of National Institute of Crop Science, RDA in 2002, which was derived from a cross between SR11878-14-4-1 of good eating-quality and high yield potential, and Suweon345 of lodging tolerance and resistance to diseases. Geumanbyeo is a medium-maturing variety with heading date of August 12 on ordinary planting in the middle plain area. It has a semi-erect plant type with culm length of 82cm, erect pubescent leaf blade and slightly tough culm with good canopy architecture. Geumanbyeo has a little bit fewer tillers per hill, and more spikelets per panicle than Hwaseongbyeo. It is slightly less tolerant to the cold stress in terms of both heading delay and spikelet fertility than Hwaseongbyeo. This variety shows delayed leaf senescence and considerable tolerance to viviparous germination at ripening stage. It shows moderately resistant to leaf blast and K1 race of bacterial blight, but susceptible to virus diseases and insect pests. The milled rice of Geumanbyeo exhibits translucent, relatively clear non-glutinous endosperm and medium-short grain. It showed lower amylose content of 18.6% and similar gelatinization temperature and better palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this variety is about 5.32 MT/ha at ordinary culture in local adaptability test for three years. Geumanbyeo would be highly adaptable to the central lowland and mid-southern mountainous areas in Korea.

"Gopumbyeo" is a new japonica rice variety developed and registered by the rice breeding team of National Institute of Crop Science, RDA in 2004, which was derived from a cross between a line SR15225-B-22-1-2 which has good eating-quality and high yield potential and a line SR15140-58-2-2-3 which has lodging and disease resistances. This variety has medium heading date of Aug. 13, medium culm length of 78 cm and tolerance to lodging. It has also relatively semi-erect pubescent leaf blades and slightly tough culm with good canopy architecture. Gopumbyeo has a bit less number of tillers per hill and more spikelets per panicle than Hwaseongbyeo. It shows less sensitivity to premature heading in delayed transplanting of 50-day old seedlings. It showed longer delay of heading date but higher spikelet fertility than Hwaseongbyeo when exposed to cold stress. This variety shows delayed leaf senescence and considerable tolerance to viviparous germination during ripening. It shows moderate resistance to leaf blast, and bacterial blight, but susceptibility to stripe virus and insect pests. The milled rice of Gopumbyeo exhibits translucent, clear non-glutinous endosperm and medium short grains. It shows similar amylose content of 19.6%, and gelatinization temperature, and better palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this variety is about 5.48 MT/ha at ordinary culture in local adaptability test for three years. Gopumbyeo would be highly adaptable to the central lowland and mid-southern mountainous areas of Korea.

"Samkwangbyeo" is a new japonica rice variety developed and registered by the rice breeding team of National Institute of Crop Science, RDA in 2003, which was derived from a cross between good quality, high yielding line Suweon361 and a disease resistant line Milyangl01. This variety has about 129 days duration from seeding to heading in central lowland and mid-mountainous areas. It is about 87 cm in culm length and moderately tolerant to lodging. It has also erect pubescent leaf blade and slightly tough culm with good canopy architecture. Samkwangbyeo has the same number of tillers per hill and spikelets per panicle as those of Ilpumbyeo. It shows less sensitivity to premature heading by lately transplanting of 50-day old seedlings. It is slightly less tolerant to cold stress in terms of both heading delay and spikelet fertility than those of Ilpumbyeo. It shows delayed leaf senescence and considerable tolerance to viviparous germination at ripening stage. It shows moderate resistance to leaf blast, bacterial blight, and stripe virus, but susceptibility to insect pests. The milled rice of Samkwangbyeo exhibits translucent, relatively clear non-glutinous endosperm and medium short grain. It has similar amylose content of 18.3% and similar gelatinization temperature, and good palatability of cooked rice compared to Ilpumbyeo. The milled rice yield of Samkwangbyeo is about 5.69 MT/ha at ordinary culture in local adaptability test for three years. Samkwangbyeo would be highly adaptable to central lowland and mid-southern mountainous areas of Korea.