"Oraebyeo" is mutation of a high quality japonica cultivar, Ilpumbyeoa new japonica rice(Oriza sativa L.) cultivar developed from by N-methyl-N-nitrosourea(MNU) treatment on fertilized egg cell by the rice breeding team of Gangwon Provincial Agricultural Res. & Ext. Service in 2006. This variety heads 20 days earlier than Ilpumbyeo and similar to that of Odaebyeo an early maturing leading cultivar of northern plain area of Korea. Compared with Odaebyeo has a good semi-erect plant type with lodging tolerance due to much shortened plant hight(l2cm shorter than Odaebyeo). Oraebyeo has similar panicle number with Odaebye where as it has more spikelets per panicle. However, this variety less the ratio of ripened grains and 1,000 grain weight than those of Odaebyeo. The yield performance of this cultivar in milled rice was about 5.09MT/ha in local adaptability test conducted for three years 2002-2004 and 5.51MT/ha in the demonstration plot of farmer's field.

Sanggolbyeo is a new japonica rice cultivar developed from Ilpumbyeo mutation lines by N-methyl-N-nitrosourea(MNU) treatment on fertilized egg cell by the rice breeding team of Gangwon Provincial Agricultural Res.& Ext. Service in 2006. This cultivar has about 135 days growth duration from transplanting to harvesting. Sanggolbyeo has short and round grain and non-glutinous endosperm with very low phytate content, below 50% of Ilpumbyeo, implying it could help men to absorb Calcium from rice. This cultivar shows midium diseases tolerance to leaf blast, bacterial blight, virus and insect pest. The milled rice yield of Sanggolbyeo is about 4.98 MT/ha at ordinary transplanting culture in the local adaptability test. Sanggolbyeo would be adaptable for the mid-northern plain areas of Korea.

AFLP markers were successfully employed to detect genetic relationship and genetic variation within and between Oryza species. Analysis of 59 accessions of Oryza species with six AFLP prim er combinations detected a total num ber of 715 polym orphic bands

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G~times E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G~times E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G~times E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.