The rice cultivar ‘Chamdongjin’ was developed to enhance the disease resistance of ‘Sindongjin’. ‘Sindongjin’, developed by the RDA in 1999, is a mega-variety with a unique grain size and excellent taste, and has been cultivated in the largest area in Korea since 2018. As ‘Sindongjin’ has been cultivated in a large area recently, problems such as pest damage are increasing, and the necessity to develop alternative cultivars is emerging. Accordingly, the multiple disease-resistant, mid-late maturing rice cultivar ‘Chamdongjin’, carrying the bacterial blight resistance gene Xa21 into the genetic background of ‘Sindongjin’, was developed. ‘Chamdongjin’ was developed by the backcrossing method using the donor parent ‘HR27195-59-3-5-5’, harboring the bacterial blight resistance genes Xa3+Xa21 and the recurrent parent ‘Sindongjin’. ‘Chamdongjin’ was selected through the pedigree method, yield trials, and local adaptability tests, with a high selection pressure for agronomic trait similarities with ‘Sindongjin’. In order to effectively improve the disease resistance, marker-assisted selection for disease resistance genes and bioassays for bacterial blight, blast, and stripe virus were performed in parallel. ‘Chamdongjin’ was confirmed to have three disease-resistance genes, Xa3+Xa21+Stvb-i. Most of agronomic traits of ‘Chamdongjin’ were similar to ‘Sindongjin’, while ‘Chamdongjin’ showed enhanced disease resistance against bacterial blight and panicle blast compared to ‘Sindongjin’. ‘Chamdongjin’, like ‘Sindongjin’, possessed a grain size-related gene, the gs3 allele, and exhibited larger grains than general Korean japonica cultivars. In addition, ‘Chamdongjin’ showed a similar or higher level of palatability compared to ‘Sindognjin’, indicating the excellent quality characteristics. In the genetic background analysis using 787 KASP markers, ‘Chamdongjin’ showed 96.3% homozygosity with ‘Sindongjin’, indicating that it had a more similar genetic background to ‘Sindongjin’ than to other existing cultivars. ‘Chamgdongjin’ is expected to be widely cultivated as an alternative to ‘Sindongjin’, which could maintain the brand value while preventing the disease damage caused to ‘Sindongjin’ (Registration No. 9310).

“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).

The ‘Seonpum’ is a rice variety derived from a cross between ‘Junam’ which has translucent milled rice and mid-late maturity and ‘Iksan457’ that the elite line has a bacterial blight resistance and medium maturing property by the rice breeding team at NICS, RDA in 2003. The heading date of ‘Seonpum’ is August 11 and four days later than check variety, ‘Hwaseong’. It has 84 cm of culm length and 124 spikelets per panicle. This variety showed similar cold tolerance to ‘Hwaseong’ while exposed to cold stress. ‘Seonpum’ showed resistance to blast disease, stripe virus and K1, K2 and K3 race of bacterial blight, but susceptible to K3a race, other viruses and planthoppers. The milled rice of this variety exhibits translucent, clear non-glutinous endosperm and short grain shape. It has similar protein content (6.7%) and amylose content (19.4%) to that of ‘Hwaseong’. ‘Seonpum’ showed better palatability index of cooked rice than that of ‘Hwaseong’. Its milled rice recovery rate is similar to those of ‘Hwaseong’. However, whole grain rate of milled rice is higher than that of ‘Hwaseong’. ‘Seonpum’ has 5.74 MT/ha of milled rice productivity in ordinary cultivation. ‘Seonpum’ could be adaptable to the middle plain area in Korea. (Registration No.6810).

‘Nokwoo’, a mid-late maturing, high dry matter yielding rice (Oryza sativa L.) cultivar with a good early growth and low-temperature germinability, was developed for whole crop silage (WCS) use. It was derived from a cross between a leafy tropical japonica ‘LK1A-2-12-1-1’ with high biomass and good germinability in low temperature and new plant type (NPT), ‘IR72225-29-1-1’ which had low tillering trait, large panicle, dark green leaf, thick and sturdy stem and vigorous root system. This cultivar had about 123 days growth period from seeding to heading, 122㎝ culm length, 29㎝ panicle length, 9 panicles per hill, 144 spikelets per panicle and 1,000-grain weight of 24.4 g as brown rice in central plain region, Suwon. This wide and long leafy WCS rice variety was weak to cold stresses similar to ‘Nokyang’ but was a little resistant to lodging in the field, strong to viviparous germination and good to low temperature germination. In addition, ‘Nokwoo’ was resistant to leaf and neck blast but susceptible to bacterial blight, rice stripe virus and brown planthopper. Its average dry matter yield for three years reached 16.5 MT/ha, 14% higher than that of ‘Nokyang’. This cultivar had 5.3% crude protein and 68.8% total digestible nutrients a little low compared to ‘Nokyang’. In Korea peninsular, ‘Nokwoo’ grows well in central and southern plain and is good to harvest between 15 to 30 days after heading to improve its feeding value and digestion rate of livestock (Grant No. 6072).

‘Jungmo1038', a mid-late maturing, high dry matter yielding rice (Oryza sativa L.) cultivar with glabrous leaf and hull, was developed for whole crop silage (WCS) use. It was derived from a cross between ‘SR24592-HB2319’ with high biomass, smooth leaf and hull and good germinability in low temperature and new plant type (NPT), ‘IR73165-B-6-1-1‘ which had low tillering trait, large panicle, dark green leaf, thick and sturdy stem and vigorous root system. This cultivar had about 125 days growth period from seeding to heading, 99cm culm length, 20cm panicle length, 13 panicles per hill, 119 spikelets per panicle and 1,000-grain weight of 23.3 g as brown rice in central plain region, Suwon. This hairless WCS rice variety was weak to cold stresses similar to ‘Nokyang’ but was resistant to lodging in the field, strong to viviparous germination and good to low temperature germination. In addition, ‘Jungmo1038’ was resistant to leaf and neck blast but susceptible to bacterial blight, rice stripe virus and brown planthopper. Its average dry matter yield for three years reached 17.2 MT/ha, 21% higher than that of ‘Nokyang’. This glabrous cultivar had 6.6% crude protein and 62.4% total digestible nutrients a little low compared to ‘Nokyang’. In Korea peninsular, 'Jungmo1038' grows well in central and southern plain and is good to harvest between 15 to 30 days after heading to improve its feeding value and digestion rate of livestock(Grant No. 5634).

The ‘Cheongun’ is a rice variety derived from a cross between ‘Suweon462’ which has translucent milled rice and medium maturity and ‘Milyang192’ that the elite line has a bacterial blight resistance and mid-late maturing property by the rice breeding team at NICS, RDA in 2012. The heading date of ‘Cheongun’ is August 13 and five days later than check variety, ‘Hwaseong’. It has 87 cm of culm length and 114 spikelets per panicle. It showed weaker cold tolerance than that of ‘Hwaseong’ while exposed to cold stress. ‘Cheongun’ showed resistance to blast disease, K1, K2 and K3 race of bacterial blight and stripe virus, but susceptible to K3a race, other viruses and planthoppers. The milled rice of this variety exhibits translucent, clear non-glutinous endosperm and short grain shape. It has similar protein content (6.7%) and amylose content (19.5%) to that of ‘Hwaseong’. ‘Cheongun’ showed better palatability index of cooked rice than that of ‘Hwaseong’. Its milled rice recovery rate is similar to those of ‘Hwaseong’. However, whole grain rate of milled rice is higher than that of ‘Hwaseong’. ‘Cheongun’ has 4.98 MT/ha of milled rice productivity in ordinary cultivation. ‘Cheongun’ could be adaptable to the middle plain area in Korea (Registration No. 5114).

‘Jungmo1029’, a late-maturing, high biomass and multiple disease resistant rice (Oryza sativa L.) cultivar, was developed for whole crop silage (WCS) use. It was derived from a cross between ‘Gillim collection1’ with high biomass and ‘Junam’ which has some of diseases resistant genes. This elite cultivar had about 127 days growth period from seeding to heading, 105 cm culm length, 11 panicles per hill, 163 spikelets per panicle and 1,000-grain weight of 21.5 g as brown rice. This WCS rice variety was weak to cold stresses similar to ‘Nokyang’ but was tolerant to lodging in the field. In addition, ‘Jungmo1029’ was resistant to leaf and neck blast, bacterial blight except race K3a and rice stripe virus but susceptible to brown planthopper. Its average dry matter yield for three years reached 17.1 MT/ha, 14% higher than that of ‘Nokyang’. This stay green cultivar had good quality for WCS with low acid detergent fiber and high total digestible nutrients similar to ‘Nokyang’. ‘Jungmo1029’ was suitable for cultivation in the central and southern plain area of the South Korean peninsula and required to harvest 15~30 days after heading to improve the digestibility of cattle (Registration No. 5104).

‘Chindeul’, a new japonica rice cultivar developed from a cross between HR22538-GHB-36-4 having brown planthopper (BPH) resistance and Iksan471 having a good eating-quality and high yield, was developed by the rice breeding team of Department of Rice and Winter Cereal Crop, NICS, RDA in 2012. This variety has about 124 days growth duration from transplanting to harvesting in west-southern coast, Honam and Youngnam plain of Korea. It has 83 cm culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows resistance to bacterial blight pathogen races from K1 to K3, stripe virus and brown planthopper. The milled rice of ‘Chindeul’ exhibits translucent, relatively clear non-glutinous endosperm and medium short grain. It has lower protein content of 5.9% and good palatability of cooked rice compared with Nampyeongbyeo. The milled rice yield performance of this variety is about 5.61 MT/ha in local adaptability test for three years. ‘Chindeul’ would be useful genetic resources for multi-resistance breeding program against disease and insect.