"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.

"Gounbyeo" is an early-maturing and good quality japonica rice variety that was developed by the rice breeding team of National Institute of Crop Science, RDA, in 2004. "Gounbyeo" was derived from a cross between Jinbul0 and Jinbul7. This variety has early heading date of July 28 and medium culm length of 68 cm, similar to Odaebyeo. It is moderately resistant to blast disease, but susceptible to bacterial leaf blight, virus diseases and insect pests. Gounbyeo showed less delay of heading date and higher grain fertility than Odaebyeo in cold-water irrigated nursery, Chucheon. The milled rice of Gounbyeo exhibits translucent, clear non-glutinous endosperm and medium short grain. Gounbyeo has lower amylose content of 18.5% and similar gelatinization temperature and good palatability of cooked rice compared to Odaebyeo. The average milled rice yield of this variety is 5.29 MT/ha at ordinary cultivation in local adaptability test for three years. Gounbyeo would be highly adaptable to mid-northern mountainous area and eastern coastal areas of 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.

"Seoanl" is a new japonica rice variety developed from a cross between Namyang9, a line of lodging tolerance and adaptable to reclaimed saline area, and Gyehwa7, a line of good-quality, adaptable to reclaimed saline area and high yield by the rice breeding team of National Institute of Crop Science, RDA, in 2005. This variety has about 131 days of growth duration from transplanting to harvesting in central plain area, and mid-western coastal area in Korea. It is about 73 cm in culm length and tolerance to lodging. It has also semi-erect pubescent leaf blade and slightly tough culm with good canopy architecture. The number of panicles per hill of Seoanl is slightly more than that of Hwaseongbyeo. Seoanl was susceptible to major diseases, blast, bacterial blight and viruses, and insect, brown plant hopper. This variety has lower amylose content of 18.8% and better palatability of cooked rice than those of Hwaseongbyeo. The milled rice yield performance of this variety is about 5.60MT/ha in local adaptability test for three years. Seoanl would be adaptable to central plain area and mid-western coastal area 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.

Blast resistance of 18 rice cultivars which recommended as a high quality rice cultivars evaluated by blast nursery test, seedling test, and field screening and sequential planting methods. Sangmibyeo, Hwayeongbyeo, and Dongjin 1 were showed high resistance reaction to leaf blast at the blast nursery continuously, while Chucheongbyeo showed highest disease severity. All of the early maturing cultivars, Odaebyeo, Junghwabyeo, and Sangmibyeo, showed the lowest compatibility against 25 blast isolates. Saechucheongbyeo, a multiline variety of Chucheongbyeo genetic background showed 45.8%, half compatibility of 82.6% in Chucheongbyeo against 25 isolates screened. Diseased leaf areas (DLA, %) of cultivars were very low level at all test sites in the field test. Three cultivars, Sangmibyeo, Ilmibyeo, and Junghwabyeo didn’t show any leaf blast lesions across the test sites. The most variable incidences of panicle blast were observed on Odaebyeo which was 42.4%, 0.4%. and 0.0% at Jaecheon, Naju, and Chuncheon, respectively. In the sequential planting method, four rice cultivars, Nampyeongbyeo, Sindongjinbyeo, Hwayeongbyeo, and Junambyeo showed less than 40% disease leaf area (DLA) from 1st planting to 7th planting, so those cultivars were considered as a durable resistant rice cultivar against rice blast diseases.

Nitrogen (N) fertilization is essential for alleviating nutrient deficiencies of the world’s population by increasing rice production, one of the most important food crops of our time. Here we established an in vivo hydroponics rice seedling culture system to investigate the physio-biochemical and molecular responses of various rice genotypes to low nitrogen application. Yoshida’s nutrient solution (YS) was used to grow rice seedlings, and at three-week-old the seedlings manifested highly stable and reproducible symptoms, such as reduced shoot growth and length. Out of 12 genetically selected or tested genotypes, almost all (11 genotypes) showed varied degrees of growth reduction response to applied nitrogen (4 and 40 ppm N for treatment and control, respectively), but SR19663-B-B-34-3-3-3-1 showed similar growth as the control though its leaf width was smaller than the control. The leaves of a 11 representative low nitrogen-responsive genotype as BG90-2 were sampled for revealing the protein profiles between low and normal (control) nitrogen application by using two-dimensional gel electrophoresis (2-DGE) followed by staining of separated proteins with silver. Fifty differentially expressed silver stained protein spots were excised from 2-D gels and 41 proteins identified using high-throughput mass spectrometry (MS) using matrix-assisted laser desorption/ionization-time of flight-MS and nano electrospray ionization liquid chromatography tandem MS. These proteins could be assigned as major (energy metabolism, photosynthesis and oxidative stress) and minor functional categories, revealing many novel low N-responsive proteins, including those having energy/photosynthesis, and defense/stress, and iron homeostasis-related functions.