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Jungmo1022’, a japonica rice cultivar, was developed by a cross between ‘Jinbu31’ (IT212616) and ‘Gyodong23’ (IT213764) by the rice breeding team at the National Institute of Crop Science, Korea, in 2000. ‘Jinbu31’ is tolerant to cold, and ‘Gyodong23’ is early maturing with high yield potential. The growth period of ‘Jungmo1022’ in paddy fields was 116 days on the North-middle highland in Korea, shorter than that of ‘Jinbu’. The culm length of ‘Jungmo1022’ was 67 cm, which was 2 cm shorter than that of ‘Jinbu’. There were 91 spikelets per panicle in ‘Jungmo1022’. The elite line was developed by shuttle breeding in a cold screening field at Chuncheon and highland Jinbu sites in order to screen for cold tolerant varieties. Forty-five lines with more than 50% fertility were selected from the F2 generation in the cold screening field, and the line SR28990-B-2-2-2 was selected by the pedigree breeding method through F3-F7 generations cultivated on the North-middle highland in Jinbu. During the yield trial conducted in 2008-2009 yield trial, an early heading, high-yielding, and cold tolerant line ‘Jinbu 48’ was selected for the local adaptability tests conducted from 2010 to 2012. The early maturing and cold-tolerant ‘Jinbu 48’ was superior to ‘Jinbu’ in exhibiting shorter heading delay, reduced culm length, and spikelet fertility under cold temperature. The new line showed a milled rice productivity of 5.69 MT/ha at Jinbu sites under North-middle highland cultivation and was registered as a new cultivar ‘Jungmo1022’ (Registration No. 5563). [ABSTRACT FROM AUTHOR]

“Baromi2” is an improved resistant early maturing rice variety with floury endosperm, and is suitable for dry milling. This variety was developed in 2019 by crossing “Suweon542,” which is ideal for dry milling, and “Jopyeong” by the rice breeding team at the National Institute of Crop Science, Rural Development Administration. The heading date of “Baromi2” was July 27 in the Honam Plains, 17 d earlier than that of “Seolgaeng.” The culm length of “Baromi2” was 76 cm, which was almost the same as its check variety “Seolgaeng”; additionally, its panicle length, panicle number, and 1,000 grain-weight of brown rice were 23 cm, 11, and 18.4 g, respectively. “Baromi2” showed strong resistance against rice blast, bacterial blight, and stripe virus disease, but was susceptible to dwarf and brown and small brown planthoppers. The milled rice yield of “Baromi2” was approximately 475 kg/10a in the local adaptability test for 3 years in the late planting culture. The grain hardness of “Baromi2” with a floury endosperm was 2 and 3 times lower than that of “Seolgaeng” with opaque endosperm and “Jopyeong” with transparent endosperm, respectively. The rice flour of “Baromi2” exhibited superior physicochemical characteristics with respect to granule size and damaged starch content compared with any other check varieties. These results inferred that “Baromi2” was suitable for dry milling and for the processed rice industry, owing to its lower milling costs and eco-friendly milling methods (Registration No. 9052). [ABSTRACT FROM AUTHOR]

Rice is the most important staple food in Korea. Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases in the rice-growing world and in Korea. Eighteen major blast resistance genes were screened in 33 leading Korean japonica varieties using 44 DNA markers. The 33 leading japonica varieties are cultivated in 659,642 ha (90.4%), and a variety of Samkwang is cultivated widely on a nation-wide scale. Four resistance genes, Pia, Pib, Pi19, and Pb1, were detected in 10-21 varieties, and the R-genes of Pii, Pish, Pita/Pita-2, Piz/Piz-t, Pi35, and Pi65(t), were present in 2-5 varieties. Five R-genes, Pit, Pi5, Pi9, pi21, and Pi40, were not detected in the Korean japonica rice varieties. A total of six varieties, two mid-late flowering varieties, Ilmi and Saeilmi, a medium flowering variety Gopum; and three early flowering varieties Jopyeong, Haedamssal, and Haedeul; were resistant to blast nursery screening over 12 years. A variety of Gopum harbored alleles for Piz/Piz-t, and three early flowering varieties, Jopyeong, Haedamssal, and Haedeul, had extensive loci of the multiple-gene family Piz/Piz-t, Pi9, and Pi40 on chromosome 6. Two mid-late flowering varieties, Ilmi and Saeilmi, harbored the Pita-2 gene, and Gopum had Pita. In the japonica rice breeding program, an effective means for enhancing stable resistance to blast would be introduced to 2-3 R genes among resistance genes Pit, Pi5, Pi9, pi21 and Pi40 which were not identified in Korean japonica rice varieties, and resistance genes Pita/Pita-2, Piz-t/Piz-5, to 2-3 R genes among and Pi20 that showed stable resistance in monogenic IRBL lines. [ABSTRACT FROM AUTHOR]

‘Jinhan’, a japonica rice variety, was developed from a cross between ‘Cheolwon68’ (IT218244) and ‘Junghwabyeo’ (IT260473) by the rice breeding team at National Institute of Crop Science in 2015. ‘Cheolwon68’ is early maturing and resistant to blast disease, and ‘Junghwabyeo’ is a cold-tolerant and high-quality variety. The growth duration of ‘Jinhan’ in the paddy field was 116 days in the Northern Central Highland in Korea, which was similar to that of ‘Jinbu’. The culm length of ‘Jinhan’ was 61 cm, which was 10 cm shorter than that of ‘Jinbu’. The panicle of ‘Jinhan’ was composed of 66 spikelets. The viviparous germination rate of ‘Jinhan’ was 33.2%. ‘Jinhan’ showed resistance to blast disease, but was susceptible to stripe virus, dwarf and black-streaked dwarf viruses, and plant hoppers. The milled rice grains of ‘Jinhan’ showed an excellent palatability index (0.23) and lower protein content (5.7%) than that of ‘Jinbu’. The grain milling characteristics of ‘Jinhan’ were similar to those of ‘Jinbu’. ‘Jinhan’ showed a milled rice productivity of 5.43 MT/ha at four sites cultivated in the Northern Central Highland (Registration No. 7318). [ABSTRACT FROM AUTHOR]

‘Yechan’ is a high grain quality mid-late maturing rice cultivar with lodging tolerance and multiple disease resistance. It was a derived from a cross between ‘Hopum’ and ‘Iksan537’ (cultivar name ‘Haepum’). ‘Hopum’ is a high grain quality mid-late maturing rice cultivar with strong lodging tolerance and ‘Haepum’ is a high grain quality medium maturing rice cultivar with multiple disease resistance. To shorten the breeding period, another culture method was applied to the F1 plants. ‘Yechan’ was selected through the pedigree method, yield trials, and local adaptability tests, with a high selection pressure for grain quality, lodging, and disease resistance. The heading date of ‘Yechan’ was August 14, one day later than that of ‘Nampyeong’. ‘Yechan’ is a cultivar tolerant to lodging and it has short culms. It has multiple disease resistance against rice blast, rice stripe virus, and bacterial blight, including the K3a race, the most virulent race in Korea. The yield of ‘Yechan’ was similar to that of ‘Nampyeong’. ‘Yechan’ showed excellent grain appearance, superior taste when cooked, and enhanced milling performance; thus, we concluded that it could contribute to the improvement of Korean japonica rice cultivar quality. ‘Yechan’, a high grain quality mid-late maturing rice cultivar with lodging tolerance and multiple disease resistance, would be suitable for cultivation in the southern plain area in Korea and has been utilized in the breeding programs aimed at enhancing the grain quality and stability for the cultivation of Korean japonica rice (Registration No. 7647). [ABSTRACT FROM AUTHOR]

Rice blast caused by the fungus Magnaporthe grisea (anamorphic: Pyricularia oryzae) is an important disease in rice and development of resistant varieties to blast is one of the most important goals in rice breeding programs. A japonica rice variety, Palgong, has shown resistance to the Korean blast pathogen since it was developed in 1996. Nine blast resistance quantitative trait loci (QTLs) in Palgong alleles were identified on chromosomes 2, 4, 7, and 11. Four QTLs of qBn2.3, qBn4.2, qBn11.1, and qBn11.2 explained 28–56.7% of total phenotypic variation, while five QTLs of qBn2.2, qBn2.4, qBn4.1, qBn7.1, and qBn7.2 explained 9.7–18.8%. In a previous study, one to four resistance genes were located on the loci qBn2.2, qBn2.3, qBn4.2, qBn11.1, and qBn11.2, however, resistance genes were not located on the loci qBn2.4, qBn4.1, and qBn7.1. A major QTL, qBn11.2, explaining 56.7% of total phenotypic variation was related to the durable resistance of Palgong. Additionally, rice stripe virus resistance of Palgong was assumed to be based on the Stvb-i gene, which is located on a major QTL qBn11.2. [ABSTRACT FROM AUTHOR]

‘Mogyang', a new high biomass yield and whole crop silage rice (Oryza sativa L.) cultivar, is developed by the rice breeding team of National Institute of Crop Science, R.D.A., Suwon, Korea, during the period from was to 2010 and released in 2011. It was derived from a cross between SR24592-HB2319/IR73165-B-6-1-1. This cultivar has about 118 days of growth duration from seeding to heading and has long and erect leaves (culm length 93 cm). It has tough thick culm with strong lodging tolerance. This cultivar has a few less tillers per hill and markedly more spikelet numbers per panicle. ‘Mogyang' has wide and stay green leaf compared other whole crop silage varieties. This new variety has grain shattering resistance and disease resistance for blast and dwarf virus. This variety has good qualities for whole crop silage with high TDN (Total Digestive Nutrient) yield and low NDF (Neutral Detergent Fiber) and low ADF (Acid Detergent Fiber) compared to common high grain yield varieties. The biomass and TDN yield performance of ‘Mogyang' was 59.5% (chemical properties), 17.7 MT/ha (biomass yield), individually in local adaptability test for three years. ‘Mogyang' is adaptable to central plain area, southern plain area of Korea. [ABSTRACT FROM AUTHOR]