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.)).

‘Haedeul’ is a high-quality rice variety with early maturing that adapts to the central region of Korea. This cultivar was crossed between ‘Gopum’, which has excellent taste, and ‘Hoban’, which has a low viviparous germination rate and is moderately tolerant of cold, by the rice breeding team of the Department of Central Area Crop Science, NlCS, RDA, in 2017. In early-transplanting cultivation, the heading date of ‘Haedeul’ was July 24 in central area of Korea, which was seven days later than that of ‘Jopyeong’. ‘Haedeul’ had a culm length of 75 cm and 99 spikelets per panicle. The viviparous germination rate of ‘Haedeul’ was 7.7%. It showed resistance to blast and bacterial blight (K1, K2, K3 race), 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 exhibited a translucent and medium short grain shape. The cooked rice grains of ‘Haedeul’ had an excellent palatability index (0.61) and lower amylose content (18.0%) than that of ‘Jopyeong’. The grain milling characteristics were better than those of ‘Jopyeong’, especially the head rice milling recovery ratio and head rice ratio (94.9%). ‘Haedeul’ milled rice productivity averaged 5.32 MT/ha at five sites under ordinary cultivation (Registration No. 7681).

‘Jinkwang’, a japonica rice variety, was developed by a cross between ‘Hopum’ (IT23527) and the F1 hybrid of ‘Unkwang’ (IT217814) and ‘Koshihikari’ (IT157335) by the rice breeding team at NICS in 2016. ‘Unkwang’ shows an early maturity and high yield and ‘Koshihikari’ is a high-quality variety. The growth duration of ‘Jinkwang’ in the paddy field was 114 days in the middle plain region in Korea, which was six days later than that of ‘Jopyeong’. The culm length of ‘Jinkwang’ was 62 cm, which was 13 cm shorter than that of ‘Jopyeong’. The panicle of ‘Jinkwang’ was composed of 100 spikelets. The viviparous germination rate of ‘Jinkwang’ was 28.3%. ‘Jinkwang’ showed resistance to blast and bacterial blight (K1, K2, and K3 races); however, it was susceptible to stripe virus, dwarf and black-streaked dwarf viruses, and plant hoppers. The milled rice grains of ‘Jinkwang’ showed an excellent palatability index (0.42) and lower protein content (6.2%) than that of ‘Jopyeong’. The grain milling characteristics were better than those of ‘Jopyeong’, especially in terms of brown/rough rice ratio and milled/rough rice ratio (75.9%). ‘Jinkwang’ showed a milled rice productivity of 5.91 MT/ha at eight sites under ordinary cultivation conditions. (Registration No. 7318).

“Samkwang1,” a japonica rice variety, was developed as a cross between “Samkwang” and F1 of Suwon152 (IT008283), which has a medium maturing and lodging resistance and Samkwang (IT284608), a high quality variety with bacterial blight resistance and mid-late maturing property by the rice breeding team at NICS in 2015. The heading date of “Samkwang1” was August 8 in the middle plain area, which was 2 days early than that of “Hwaseong.” “Samkwang1” had a culm length of 77 cm, which was 7 cm shorter than that of “Hwaseong,” and it had 128 spikelets per panicle. The viviparous germination rate of “Samkwang1” was 2.1%. “Samkwang1” showed resistance to blast, bacterial blight (K1, K2, and K3 race) and stripe virus, but was susceptible to the K3a race of bacterial blight, dwarf and black streak dwarf viruses, and plant hoppers. The milled rice of this variety exhibits translucent and medium short grains. The cooked rice grains of “Samkwang1” have an excellent palatability index (0.35) and lower protein content (6.2%) than that of “Hwaseong.” The characteristics related to grain milling were better than those of “Hwaseong,” especially the head rice milling recovery ratio and head rice ratio (94.2%). “Samkwang1” showed 5.62 MT/ha of milled rice productivity at 11 sites under ordinary cultivation conditions (Registration No. 6798).

Cheongpum’, a japonica rice variety, was developed from a cross between Yeongdeog45 and ‘Samkwang’ by the rice breeding team at NICS in 2015. The heading date of ‘Cheongpum’ was August 10 in the middle plain area, which was two days later than that of ‘Hwaseong’. ‘Cheongpum’ had a culm length of 79 cm, which was 5 cm shorter than that of ‘Hwaseong’, and 116 spikelets per panicle. The viviparous germination rate of ‘Cheongpum’ was 27.9%. It showed resistance to blast, bacterial blight (K1, K2, K3 race), and stripe virus, but susceptibility to the K3a race of bacterial blight, dwarf, and black streak dwarf viruses, and plant hoppers. The milled rice of this variety exhibited a translucent and medium short grain shape. The cooked rice grains of ‘Cheongpum’ had an excellent palatability index (0.41) and lower amylose content (18.8%) than that of ‘Hwaseong’. The grain milling characteristics were better than those of ‘Hwaseong’, especially the head rice milling recovery ratio and head rice ratio (94.1%). ‘Cheongpum’ showed 5.36 MT/ha of milled rice productivity at 11 sites under ordinary cultivation (Registration No. 6799).

The ‘Jungmo1023’ is the japonica rice variety developed from a cross between Yeongdeog34 and F1 of Iksan456 and SR21097-B-B-19-2-2 by the rice breeding team at NICS in 2012. The heading date of ‘Jungmo1023’ is August 3 in middle plain area and it is six days earlier than ‘Hwaseong’. ‘Jungmo1023’ has 80 cm of culm length which is 4 cm shorter than those of ‘Hwaseong’ and 107 spikelet per panicle. The premature heading rate of ‘Jungmo1023’ was 3.3%. It showed resistance to blast, bacterial blight (K1, K2, K3 race) and stripe virus, but susceptibility to K3a race of bacterial blight, dwarf and black streak dwarf viruses and planthoppers. The milled rice of this variety exhibits translucent and medium short grain shape. It has better palatability index of cooked rice (0.24) and lower amylose content (18.0%) than that of ‘Hwaseong’. The characteristics related to grain milling were better than those of ‘Hwaseong’, especially head rice milling recovery ratio and head rice ratio (96.2%). ‘Jungmo1023’ showed 4.56 MT/ha of milled rice productivity at 7 sites in ordinary cultivation. However, ‘Jungmo1023’ showed early cultivation culture adaptability because of 98% of its yield potential (4.99 MT/ha) compared to high yielding early-maturing variety ‘Jopyeong’. ‘Jungmo1023’ could be adaptable to the middle plain, mid-mountainous and north-east coastal area in Korea (Registration No. 5115).