‘Miho’ (Milyang300) was developed as a processing rice by means of pedigree selection. ‘Milyang300’ has slightly opaque seeds with low amylose content (11.2%), unlike cultivars such as Baegjinju and Milky-queen, which have seeds with low amylose but are opaque. ‘Milyang300’ was selected and named ‘Miho’ in 2016. ‘Miho’ is a late-maturing ecotype with an average heading date of August 21^st. It shows mild resistance to leaf blast and strong resistance to rice stripe virus, and bacterial blight (K1-K3); however, it is susceptible to brown plant hopper infestation. The yield capacity of ‘Miho’ determined over 3 years of regional yield trials was 565 kg/10 a. In terms of processing properties, ‘Miho’ shows no significant differences in textural properties when stored for 6-48 h at 3℃ and -18℃. Moreover, the physical properties of ‘Miho’ remain unaltered during freeze-thaw processes. Thus, the low-amylose rice ‘Miho’ may be suitable for the production of refrigerated and frozen cooked rice (Registration No. 7656).

‘Shingil’ was developed as a processing rice for specialization as a rice flour by means of mutation breeding from ‘Hanareum’ MNU (N-methyl N-nitrosourea) treatment. The bulk population was displayed from M₁ to M₆, followed by pedigree methods from M₇, where line selection was carried out based on the amylose content, with opacity in the endosperm. The result was that ‘Milyang317’, which has a somewhat high amylose content as well as a high ratio of starch opacity, was selected and named as ‘Shingil’ in 2017. ‘Shingil’ is a mid-maturing ecotype with a heading date of August 10, showing resistance to both leaf/panicle blast and rice stripe virus (RSV), but susceptibility to Bph. ‘Shingil’ showed a low viviparous germination rate of 5.2%. The yield capacity of ‘Shingil’ was 745kg/10a over two years based on a regional yield test. The amylose content of ‘Shingil’ is 23.4% with the grain showing opacity in most parts of the endosperm, which is caused by the round particle shape, unlike the polygonal shape of ordinary grains. Thus, ‘Shingil’ could be used as a rice flour source in various processing field and dry milling industries where milling costs could be saved (Registration No. 8019).

‘Dodamssal’ was developed as a functional rice by means of a cross between ‘Goamibyeo’, a high amylose cultivar for noodle rice, and ‘Goami2’, a mutant cultivar derived from ‘Ilpum’ treated with N-methyl N-nitrosourea (MNU), with a high amylose content. The bulk population was displayed from F₂ to F₄, followed by pedigree methods from F₅, where line selection was performed based on amylose mutants with an opaque endosperm. Finally, ‘Milyang261’, which has a high amylose content and high resistant starch content, was selected and named as ‘Dodamssal’ in 2013. ‘Dodamssal’ is a mid-maturing ecotype with a heading date of August 10, susceptibility to both viruses and insects, and showed a slightly high viviparous germination rate of 23.4%. The yield capacity of ‘Dodamssal’ was 529 kg/10a over a 3-year regional yield test and would be suitable for cultivation in the middle and southern plain areas of Korea. The amylose content of ‘Dodamssal’ is 42.8%, with a grain appearance of opaque endosperms. Moreover, the starch granule of ‘Dodamssal’ was a round particle shape, unlike the polygonal shape of the ordinary grain. ‘Dodamssal’ is functional variety with resistant starch and dietary fiber contents of 13.6% and 5.3%, respectively (Registration No. 5637).

Rice tungro disease is a serious threat to rice production in South and Southeast Asian countries. Rice production in these countries has been intensified, often through continuous cultivation of rice. We conducted a screen of the resistance to tungro virus disease in Korean japonica rice. Dongjin, Hwaseong, and Sangju were varieties resistant to Rice tungro spherical virus (RTSV) but susceptible to Rice tungro bacilliform virus (RTBV). RTSV-resistant variety Sangju was crossed with RTSV-susceptible variety Unkwang to conduct a genetic analysis for RTSV resistance originating from Sangju. Evaluation of 201 F2 plants from the cross between Unkwang and Sangju showed that there were 85 plants showing resistance, and that 116 plants were susceptible, indicating a ratio fitting a 7:9 ratio ratio (χ² = 0.54; p = 0.46). Thus, the resistance to RTSV in Sangju might be controlled by two recessive genes. This result indicates that Sangju might serve as a useful genetic source for diversification of RTSV resistance and stabilization of resistance through gene pyramiding.