‘Dabokchal, a glutinous rice variety (Oryza sativa L.) with a medium late maturation period was developed by the Department of Crops and Food, JARES in 2020. It was derived from a cross between the glutinous cultivar ‘Shinmyeongheugchal’ with the good glutinous properties and ‘Hwangkumnodeul’ as a high yielding source. The progenies of the cross were selected by bulk and pedigree breeding method until the F₈ generation. As a result, a promising line, JR53-28-4-10-5-3, was advanced and designated as the name of ‘Jeonbuk12’ in 2018. The ‘Jeonbuk12’ local adaptability test was carried out at four locations during 3 years from 2018 to 2020. This variety headed on August 13, which was eight days later than ‘Sinseonchal’ in Honam plane. The culm and panicle length of this variety was 70 cm and 22 cm, respectively. This variety has about 16 tillers per hill and 92 spikelets per panicle. The ratio of ripened grain is approximately 84.9% and 1000-grain weight was 24.9 g in brown rice. This variety has a higher amylose content compared to that of ‘Sinseonchal’. The yield performance of brown rice was 591 kg/10a in the local adaptability test. This cultivar is considered to be adaptable to the Honam plain area of Korea (Registration No. 9602).

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).