‘Sangbo’ is a japonica rice (Oryza sativa L.) variety with high head rice grain ratio and good ripened grain color, as well as resistance to rice dwarf virus (RDV) and bacterial blight disease (BB). It was developed by the rice breeding team of the Yeongdeok Branch of the National Institute of Crop Science, RDA, Korea, in 2015. This variety was derived in the 2002 summer season from a cross between ‘Yeongdeog32’, with high eating quality, and ‘Nampyeong’, with a high milling ratio. In 2012, a promising line, YR24256-142-5-3-1-1-2, selected by the pedigree breeding method, was designated the name, ‘Yeongdeog59’. After performing a local adaptability test at nine locations from 2013 to 2015, ‘Yeongdeog59’ was released with the name ‘Sangbo’ in 2015. ‘Sangbo’ has a culm length of 77 cm and a medium-late growth duration. This variety was resistant to K1, K2, and K3 races of bacterial blight, along with the dwarf virus, and was moderately resistant to leaf blast disease. Based on the results of a panel test, ‘Sangbo’ has translucent and clear milled rice kernel without white core and belly rice, and good eating quality. The yield potential of ‘Sangbo’ in milled rice was approximately 6.21 MT/ha at the ordinary fertilizer level of the local adaptability test (LAT). This cultivar would be adaptable to the middle plain, south plain, Yeongnam plain, east coastal area, and south mid-mountainous areas of Korea (Registration No. 7284, 2018.06.25).

Rice research in Korea during the past 100 years has gone through tremendous changes and improvements as the country underwent a turbulent history of transformation. Full-scale R&D modernization began in the 1970s, when the government focused policy on achieving self-sufficiency in rice in order to establish the foundation for national economic growth. A major landmark was reached by the development of the rice variety “Tongil” and its cultivation technology, which was at the core of the unprecedented Korean “Green Revolution”. Since achieving self-sufficiency in rice, the breeding goal of Korea moved from increasing yield to improving grain quality as more consumers began to seek high quality food products in the 1980s. This change led to the establishment of the high quality rice breeding platform for enhancing the global competitiveness of Korean rice to cope with the opening of domestic rice market in the 2000s. Currently, the major breeding goals in rice are developing premium quality cultivars for table rice and specialized cultivars for boosting processed food industry. To date, the National Institute of Crop Science has released a total of 300 rice cultivars, including 202 table rice and 98 specialized usage cultivars. Diverse technologies have been developed and utilized for breeding new rice cultivars to meet changing needs. In the next 100 years of rice breeding, the convergence of traditional crop improvement technologies and the new breeding technologies utilizing recent advances in biotechnology will play a crucial role in enhancing breeding efficiency.

‘Yeongbo’ is a variety of japonica rice (Oryza sativa L.) with good eating quality, resistance to rice stripe virus, rice dwarf virus, and bacterial blight disease. It was developed by the rice breeding team of the Yeongdeok Branch, National Institute Crop Science, Rural Development Administration in 2014. This variety was derived from a cross between ‘Yeongdeog35’ with good eating quality and ‘Saekyehwa’ with good plant type in the 2002 summer season. A promising line selected through the pedigree breeding method, YR24269-1-2-1-2-3-3, was designated as ‘Yeongdeog57’ in 2011. After a local adaptability test at nine locations from 2012 to 2014, ‘Yeongdeog57’ was released under the name of ‘Yeongbo’ in 2014. ‘Yeongbo’ had a short culm length of 66 cm and medium growth duration. This variety was resistant to K1, K2, and K3 races of bacterial blight, rice stripe virus, and dwarf virus, and moderately resistant to leaf blast disease. ‘Yeongbo’ had translucent and clear milled rice kernel without white core and belly, and good eating quality according to a panel test. The yield potential of ‘Yeongbo’ in milled rice was approximately 5.75 MT/ha at an ordinary fertilizer level in the local adaptability test. This cultivar would be adaptable to middle plain area, south plain area, Yeongnam plain area, east costal area, and south mid-mountainous area. (Registration No.6804)

Rice stripe virus (RSV) is one of the major constraints in rice production which is transmitted by the small brown plant hopper, Laodelphax striatellus. Identifying new resistance genes from diverse sources is important for rice breeding programs to enhance the resistance level and/or to overcome the breakdown of resistance genes. This study was conducted to identify novel sources of resistance against RSV. We used five RSV resistant varieties that do not harbor Stv-bⁱ. The presence of known genes for RSV resistance was identified using the InDel7 marker for Stv-bⁱ, two Indel (Sid primer set) markers for Stv-b, and DNA sequence analysis for OsSOT1. We revealed that two varieties, 02428 (IT236925) and Tung Ting Wan Hien 1, are novel RSV resistance sources.

Oryza sativa ‘Sinbo’ is a cultivar of japonica rice with good eating quality as well as resistance to rice dwarf virus (RDV) and bacterial blight disease (BB). It was developed in 2013 by the rice breeding team of Yeongdeok Branch, National Institute of Crop Science, RDA, Korea. This cultivar was derived from a cross between ‘Yeongdeog34‘, a cultivar with good eating quality, and ‘Saekyehwa’, a cultivar of a good plant type, in summer of 2002. A promising line (YR24264-25-3-2) selected using the pedigree breeding method was designated as ‘Yeongdeog55’ in 2010. After carrying out the local adaptability test at nine locations from 2011 to 2013, ‘Yeongdeog55’ was published under the name of ‘Sinbo’ in 2013. ‘Sinbo’ is a medium-late maturing cultivar with a short culm length of 70 cm. This cultivar is resistant to K1, K2, and K3 races of bacterial blight as well as to dwarf virus, and it is moderately resistant to leaf blast disease. The results of the panel test indicated that ‘Sinbo’ has translucent and clear milled rice kernel without white core and belly rice as well as good eating quality. The yield potential of ‘Sinbo’ was approximately 5.67 MT/ha at the ordinary fertilizer level in the local adaptability test (LAT). This cultivar could be adaptable to the middle plain, south plain, Yeongnam plain, east costal area, and south mid-mountainous area of South Korea. (Registration No. 5643)

Rice production is largely affected by various environmental conditions such as cold, heat and flooding. Here, to identify cold tolerant QTLs at seedling stage in rice, we generated RIL population derived from a cross between Hanareum 2 and Unkwang which are a highly cold sensitive and cold tolerant, respectively. We observed cold phenotype of this population in the growth chamber conditions and natural field conditions. For observation of cold tolerant phenotype of RIL population in the growth chamber, we treated cold stress (5~13°C) for 14 days and recovery for 4 days. When we examined the phenotype of RIL in the field conditions, temperature range in the field conditions was about 6 to 25°C in 2015~2016. We named QTLs as Seedling Cold Tolerant (SCT) in growth chamber and Cold induced Yellowing Tolerant (CYT) in the field, respectively. Three QTLs for SCT and 5 QTLs for CYT were detected on chromosome 1, 6, 7, 8, 10, 11 and 12. Among these QTLs, qSCT12 on chromosome 12 showed 26.3 LOD score with 25.5% of phenotypic variation. When qSCT11.1 and qSCT12 were combined, cold tolerant was most strongest in our experimental conditions. qCYT10 on chromosome 10 was identified in field experiment on both 2015 and 2016. These results may provide useful information for a marker-assisted breeding program to improve cold tolerance in rice.

This study was conducted to analyze the starch and pasting properties of fourteen glutinous rice varieties with different maturity, and we compared the textural characteristic difference in relation to stickiness of glutinous rice cake. The whiteness values of grain appearance showed significantly differences in the order of early < medium < mid-late maturing glutinous rice varieties. Early maturing glutinous rice varieties exhibited a little high tendency for crude protein content than that of other varieties. Mid-late glutinous rice varieties showed higher of short chain ratio of 6 to 12 in DP of amylopectin whereas, medium length chains of 13 to 24 were significantly low. According to Rapid Visco-Analyzer measurement glutinous rice flours and starches, peak time showed high negative correlation with short chains of 6 to 12 in DP. The hardness of mid-late maturing glutinous rice cake was distinctly lower than that of the other glutinous rice varieties. Furthermore, mid-late maturing glutinous rice varieties, Baegseolchal, Dongjinchal and Baekogchal tend to show lower and slower in hardness changes of rice cake during storage. The hardness changes of glutinous rice cake had positive correlation with the amylose content and peak time and negative correlation with short chains of 6 to 12 in DP of amylopectin, respectively.

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.

A rice variety ‘Daebo’ 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 2011. This variety derived from a cross between ‘YR21247-68-1’ with good plant type and ‘Yeongdeog35’ with good eating quality conducted in 2002 summer season. A promising line, YR23940-B-17-1-2, selected by bulk and pedigree breeding method was designated as the name of ‘Yeongdeog51’ in 2008. After the local adaptability test was carried out at seven locations from 2009 to 2011, ‘Yeongdeog51’ was released as the name of ‘Daebo’ in 2011. ‘Daebo’ is short culm length as 63 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 resistance. ‘Daebo’ 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 ‘Daebo’ in milled rice is about 5.93 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to middle plain, south plain, mid-west costal area, and south mid-mountainous area.