Rice cultivar ‘Saeodae1’ was generated by crossing ‘Saeodae’, which has good taste and a medium-short round grain, and ‘Unbong51’ which has a combined disease resistance and translucent grain. The aim of this was to develop an early maturing rice cultivar with medium-short round grain and high quality rice which adapts to the mid-northern inland plain, northern-middle highland, northern-east coastal region of Korea, and was undertaken by the rice breeding team of Cheolwon Substation, National Institute of Crop Science (NICS), RDA, in 2022. In the normal growing season in the mid-northern inland plain of Korea, the heading date of ‘Saeodae1’ was July 25 around the same time in ‘Odae’. ‘Saeodae1’ had a 75 cm culm length, 1 cm longer than that of ‘Odae’, and 75 spikelets per panicle, similar to that of ‘Odae’. The ripened grain ratio (84.7%) of ‘Saeodae1’ was higher than that (72.5%) of ‘Odae’. The head rice ratio (60.9%) of ‘Saeodae1’ was higher than that of ‘Odae’, which is advantageous in securing yield. 1,000 grain weight (25.9 g) was similar to that of ‘Odae’, but it has a smaller degree of white core rice, leading to an improved consumer preference. ‘Saeodae1’ exhibited resistance to blast and bacterial blight (K1, K2, K3 races), but was susceptible to the K3a race of bacterial blight, stripe virus, dwarf and black streak dwarf viruses, and plant-hoppers. The milled rice of this variety was translucent, with a medium-short grain shape. The cooked rice grains of ‘Saeodae1’ exhibited a good palatability index (0.13) and similar amylose content (18.2%) to that of ‘Odae’. Grain milling characteristics, including head rice milling recovery ratio and head rice ratio (82.0%) were better than those of ‘Odae’. Average milled rice productivity of ‘Saeodae1’ was 5.59 t/ha at six sites in the normal growing season (Registration No. 10182(2024.5.14.)).

There are farmer’s demands to develop early-maturing cultivar in order to replace Odae variety to mid-northern inland plain and southern mountainous area of Korea. Saeodae was developed by the rice breeding team of Cheolwon Substation, National Institute of Crop Science (NICS), RDA in 2012. This cultivar was derived from the cross between Geuroobyeo and Suweon 472 in 2001 summer season, and selected by a promising line, SR27376-2-2-1-3, was selected and designated as the line of Cheolweon 81 in 2010. The local adaptability test of Cheolweon 81 was carried out at four locations from 2010 to 2012 and it was named as Saeodae. The heading date of Saeodae is July 25 in Cheolwon area, which is 2 days earlier than that of Odae. This variety has 66cm in culm length and 77 spikelets per panicle. Its 1,000 grain-weight of brown rice is 26.5 g, which is similar to that of Odae. Germination rate at low temperature of this variety is about 70%, and viviparous germination is 17.7%. Cold tolerance of this cultivar is still not good, just mediocre. It shows strong lodging resistance. And premature heading, occurrence of wilting during ripening stage, and leaf senescence at maturing are similar to those of Odae. This variety shows resistance to leaf blast disease, but susceptible to bacterial blight, virus disease and insect pest. This variety has translucent and clear milled rice kernel without white core and belly rice. The yield potential of Saeodae was about 5.26 MT/ha at ordinary fertilizer level in local adaptability test for three years. This variety would be adaptable to mid-northern inland plain and southern mountainous area of Korea.