• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.472-477
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• 2018

"Hyangcheola" is a new japonica rice variety developed as a cross between "Joryeong" and "Seolhyangchal" by the rice breeding team at NICS in 2014. The heading date of "Hyangcheola" is July 28 in the middle plain area, which is 8 days earlier than that of "Hwaseong." "Hyangcheola" has a 76 cm long culm, which is 8 cm shorter than "Hwaseong" and has 86 spikelets per panicle. The viviparous germination rate of "Hyangcheola" was 27.9%. It showed resistance to stripe virus but susceptibility to bacterial blight (K1, K2, and K3 races), dwarf and black streak dwarf viruses and planthoppers. The milled rice of this variety exhibits translucent and medium short grain shape. The protein content of "Hyangcheola" was 8.2%, which was 1.5% higher than that of "Hwaseong." "Hyangcheola" is a rice with a fragrant aroma. The content of iron in 100 g of brown "Hyangcheola" rice was 15.12 mg, which is 3.69 mg higher than that of "Hwaseong," and the zinc content was 32.24 mg, which is 8.75 mg more than that of the comparative variety "Hwaseong." The average milled rice yield of "Hyangcheola" was 4.8 MT/ha at our sites under ordinary cultivation (Registration No. 6807).

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.490-496
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• 2018

"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).

• Korean Journal of Breeding Science
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• v.51 no.1
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• pp.34-40
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• 2019

'Jungmo1033', a japonica rice variety, was developed by the rice breeding team at the National Institute of Crop Science (NICS) in 1992. It is derived from a cross between a native variety 'Jagwangdo', which has translucent milled rice and medium maturity; and 'Hwayeong', which is an elite line with bacterial blight resistance and mid-late maturity. The heading date of 'Jungmo1033' was August 10 in the middle plain area of Korea, which was two days later than that of 'Hwaseong'. 'Jungmo1033' has a culm length of 79 cm, which was 5 cm shorter than that of 'Hwaseong', and 105 spikelets per panicle. 'Jungmo1033' showed resistance to bacterial blight (K1, K2, and K3 races) and stripe virus, but susceptibility to the K3a race of bacterial blight, dwarf and black-streaked dwarf viruses, and planthoppers. The milled rice of this variety exhibited translucency and a medium short grain shape. It had an excellent appearance and lower amylose content (19.1%) 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 (94.8%). 'Jungmo1033' showed a milled rice productivity of 5.38 MT/ha at 11 sites under ordinary cultivation conditions. (Registration No. 5723)

• Korean Journal of Agricultural Science
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• v.1 no.1
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• pp.9-26
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• 1974

1. Results in Nursery This experiment was carried out on the effect of the seed treament, soil preparations, kinds of covering soil and inside covering methods in two rice varieties, 'Tongil' and 'Akibare' to find out the most reasonable model of the flat nursery bed, with which lower cost is required comparing with the tunnel nursery. The results obtained are as follows: (1) The seedling of all plots of the ordinary seed were very poor compared to the plots of sprouted seed. (2) In case that the variety 'Tongil' was cultivated on the dry nursery bed, the good seedling percentage and the plant height rat io were significantly increased but the other characteristics of the seedling were not noticeable. (3) The kinds of the covering soil had not an effect on the seedling growth significantly. (4) Inside straw mulching was seemed effective for the protection in the case of the extreme high temperature and heavy rain fall, even though there was not significant differences between inside straw mulching and no treatments at the flat type nursery. (5) Difference of seedling growth between the flat type nursery and the tunnel type nursery was not significant. And it's reason was thought that the covering period of polyethylene film was short in semi hot nursery for the common early transplanting cultivation of rice. (6) The percentage of good seedling was higher at 'Akibare' than 'Tongil', variety but the number of seedling leaf and the seedling growth ratio in height were significantly increased in the variety 'Tongil'. The other seedling characters between there two varieties were not significantly different. 2. Results after transplanting This experiment was conducted to study on the ripening percentage, rice yield and disease, appearance of the seedling from sprouted seed plots including common irrigated nursery as check plot after transplantnig. The results obtained are summarized as follows: (1) The rice yield, the yield components and the appearance of leaf discoloration of both varieties, 'Tongil' and 'Akibare' were slightly betterat the plot of the standard tunnel nursery than that of the flat nursery with inside mulching or the among these three plots. (2) For 'Tongil' variety, the ripening percentage and the rice yield were significantly decreased at the common irrigated nursery compared with semi hot nursery. (3) The ripening percentage and the rice yield of 'Akibare' contrasted with 'Tongil' were significantly decreased at thesemi 'hot-nursery compared with common irrigated nursery. The main reason was thought to be the injury of the rice stripe disease (Rice stripe disease virus). Considering above mentioned experimental result, the seedling of 'Tongil' must be cultivated on the semi bot nursery for better ripening percentage as well as rice yield and for prevention of red discoloration. And as a model of semi hot nursery, the polyethylene covering nursery of standard tunnel type is most desirable but that of flat type with inside straw mulching is thought to be desirable too.

• Korean Journal of Breeding Science
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• v.51 no.3
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• pp.263-276
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• 2019

'Sinjinbaek' is a bacterial blight (BB)-resistant, mid-late maturing rice cultivar with high grain quality. To diversify the resistance genes and enhance the resistance of Korean rice cultivars against BB, 'Sinjinbaek' was developed from a cross between 'Iksan493' (cultivar name 'Jinbaek') and the F₁ cross between 'Hopum' and 'HR24670-9-2-1' ('HR24670'). 'Jinbaek' is a BB-resistant cultivar with two BB resistance genes, Xa3 and xa5. 'Hopum' is a high grain quality cultivar with the Xa3 resistance gene. 'HR24670' is a near-isogenic line that carries the Xa21 gene, a resistance gene inherited from a wild rice species O. longistaminata, in the genetic background of japonica elite rice line 'Suweon345'. 'Sinjinbaek' was selected through the pedigree method, yield trials, and local adaptability tests. Using bioassay for BB races and DNA markers for resistance genes, three resistance genes, Xa3, xa5, and Xa21, were pyramided in the 'Sinjinbaek' cultivar. 'Sinjinbaek' exhibited high-level and broad-spectrum resistance against BB, including the K3a race, the most virulent race in Korea. 'Sinjinbaek' is a mid-late maturing rice cultivar tolerant to lodging. It has multiple disease resistance against BB, rice blast, and stripe virus. The yield of 'Sinjinbaek' was similar to that of 'Nampyeong'. 'Sinjinbaek' showed excellent grain appearance, good taste of cooked rice, and enhanced milling performance, and we concluded that it could contribute to improving the quality of BB-resistant cultivars. 'Sinjinbaek' was successfully introgressed with the Xa21 gene without the linkage drag negatively affecting its agronomic characteristics. 'Sinjinbaek' improved the resistance of Korean rice cultivars against BB by introgression of a new resistance gene, Xa21, as well as by pyramiding three resistance genes, Xa3, xa5, and Xa21. 'Sinjinbaek' would be suitable for the cultivation in BB-prone areas since it has been used in breeding programs for enhancing plants' resistance to BB (Registration No. 7273).