“Jeongdami” is a specialized rice (
The rice cultivar, ‘Dapum’, is a high-quality, late-maturing rice with low amylose content developed by the Chungcheongnam-do Agricultural Research and Extension Services (Yesan, Korea). Dapum was derived from a cross between Miho, a processed rice cultivar known for its cultivation stability and low amylose content, as the maternal parent, and Daohuaxing2, a high-quality aromatic rice cultivar, as the paternal parent. Subsequently, a pedigree breeding method was employed, and yield trials conducted from 2019-2020, followed by local adaptability tests from 2020-2021. As a result of the local adaptability test, the heading date of ‘Dapum’ was August 28th, which is slower than the cultivars mainly cultivated in the Chungnam Province in Korea; therefore, it can be ripened at an appropriate temperature. The yield of milled ‘Dapum’ rice under standard fertilizer conditions was approximately 572 kg/10a, which was 15 kg/10a higher than that of Miho. The amylose content of ‘Dapum’ was 12.5%, similar to that of Miho, and the glossiness of cooked rice, which reflects its indirect eating quality, was 86.8, which was 7.0 points higher than that of Miho. The new rice cultivar, ‘Dapum’, is expected to be used in various ways, such as for cooked and processed rice, due to its low amylose content and good eating quality. Further, it has the potential to enhance the competitiveness of rice production in the Chungnam Province by diversifying the rice market, which has traditionally focused on mid-maturing, non-glutinous rice (Registration No. 10181).
A total of 285 Korean rice cultivars were used for amylose content and genetic analyses using KASP markers related to the amylose content. We used three polymorphic KASP markers targeting the
‘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 21st. 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).
‘Golden queen 3’, an aromatic rice variety, was developed by Seedpia inc. (Suwon, Korea) breeding company in 2014. This cultivar was derived from a cross between ‘HJ-11’, a high-yield, aromatic line, and ‘JCH33M-15-1-9-1’, which has a low amylose content. During the F3-F8 generation, breeding lines were selected using a pedigree breeding method. The most promising line (JS9-3-73-15-5-1-5-3-1-1) was advanced and named ‘SP005’ in 2013. This variety was headed on August 13, two days later than ‘Hwayeong’ in the ‘in middle plane’ is commonly used to distinguish rice cultivation areas in Korea, so I think it's no problem to the understanding for readers (including farmers). The culm and panicle lengths of this variety were 75.7 cm and 20.1 cm, respectively. It has approximately 14.7 tillers per hill and 104.8 spikelets per panicle, and the 1000-grain weight was 21.8 g. The yield performance was 5.47 MT/ha in the local adaptability test, and the amylose content of this variety was 12.5%. 2-Acetyl-1-pyrroline was detected as the major volatile ingredient in aromatic rice, and a 1 bp insertion on the 14th exon (
‘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).
‘Gawagi1’ is an early maturing, low amylose rice variety with a medium to short culm, developed by Gyeonggi-Do Agricultural Research & Extension Services, Hwaseong, Korea in 2016. ‘Gawagi1’ was derived from the cross between ‘Baegjinju’ and ‘Sangmibyeo’ in 2004. Heading date was 4th of August 15 day earlier than ‘Baegjinju’ in Gyeonggido. The culm length was 67 cm. It had 15 panicles per hill and 104 spikelets per panicle. It is a medium-grain variety whose 1,000 grains weight of brown rice is 19.3 g. The protein content of milled rice was 6.3%, which is higher than that of ‘Baegjinju’ and its amylose content was 8.2% which is lower than that of ‘Baegjinju’. Its milling ratio is 75.5%, which is higher than that of ‘Baegjinju’. The yield of milled rice was 4.99 MT/ha under the standard cultivation practices at the local adaptability tests in 3 regions from 2014 to 2016. ‘Gawagi1’ is highly adaptable to Gyeonggido, especially to the northern region of Han River. (Registration No. 7280)
‘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).
A statistical analysis of 9,771 non-glutinous rice in breeding line germplasm collected from Korea (2,836), China (2,136), Japan (1,219), and the Philippines (1,213) was conducted using normal distribution, variability index value (VIV), analysis of variation (ANOVA) and Ducan’s multiple range test (DMRT) based on the data obtained from NIRS analysis. According to the normal distribution, the average protein content was 7.9%, and non-glutinous rice ranging over 10% amylose had 23.6% average content. Most resources were between 5.3 and 10.5% in protein content, and 15.7 and 31.5% in amylose content. The VIV was 0.54 for protein, and 0.83 for amylose. The average amylose content was 25.18%, 24.54%, 22.08%, and 21.47% in Filipino, Chinese, Korean, and Japanese resources, respectively, wheereas the average protein content was found to be 8.19%, 7.79%, 7.58%, and 7.42% in Filipino, Chinese, Korean, and Japanese resources, respectively. The ANOVA of amylose and protein content showed significant differences at the level of 0.01. The F-test value was 412.2 for amylose content, and 108.4 for protein when compared with the critical value of 3.78. The DMRT of amylose and protein content showed significant differences (p<0.01) among resources from different countries. The Filipino resources had the highest level of amylose and protein content, whereas; the lowest level of amylose and protein content were found in Japanese when compared with resources of other origins. These results are recommended as helpful materials in the field of breeding.
Starch properties of 32 Korean barley cultivars (
Saemimyeon, a Tongil type, medium-late maturing rice variety, is especially used for preparing rice noodles. Its high amylose content was developed to fit market demands and to be affordable for rice processing industries. One of the high yielding lines, Milyang181 (Hanareum), was used in the final three-way cross of IR50*2/YR18241-B-B-115-1-1 for yield improvement and cultivation stabilization, including disease resistance. YR24235-10-1-3, a high yielding and compact plant type, was selected and named Milyang278 after yield test at NICS (RDA, Miryang) in 2010. It was subjected to regional yield test at six sites in the middle and southern plain areas of South Korea. Saemimyeon heading occurs on August 12 and is a mid-late maturing cultivar, with resistance to leaf blast, rice stripe virus, and bacterial blight (K1-K3a), but it is susceptible to major diseases and insect pest infestation. Saemimyeon showed a high amylose content of 26.7%, with a relatively low KOH digestion value of 3.5, which are key factors in rice noodles and pasta processing. In the local adaptability tests, the yield of Saemimyeon was 7.08 MT/ha—an increase of approximately 106% compared to that of Dasan. Thus, Saemimyeon is suitable for cultivation in the southern and middle plain areas of South Korea.
The Jinsang 2 cultivar is a new late-maturing, low amylose rice variety with a medium to short culm created by the Seedpia Inc. breeding company in 2012. This variety was derived from a cross between Junam, a high-yield and lodging tolerant source, and DM3-8-72-9, which was derived from a cross between Donjinchal and Milkyqueen, with a low amylose content and superior agronomic traits. A general single seed descent method was applied to develop Jinsang 2 in the F3-F4 generations. During the F5-F8 generations, the breeding lines were selected through a pedigree breeding method. A promising line, JS6-B-52-8-3-5-1-B-B-B, was selected and named HJ-6 in 2011. This variety headed on the 25th of August, which was 14 days later than Hwayoung. The culm and panicle length of the variety was 71.6 cm and 19.9 cm, respectively. The milled rice from the variety had a dull and medium- to short-grain, and the 1,000-grain weight was around 20.0 g. It had a low amylose content of 12.2% and a low protein content of 6.8%. The yield performance of Jinsang 2 milled rice was about 5.36 MT/ha from the ordinary culture replicated yield trial test.
The amylose contents of rice determine eating quality which is one of the major traits in rice breeding program. To identify the low-amylose gene of the japonica rice cultivar Baegjinju, genetic analysis was conducted using 200 F2 population derived from a cross between the japonica cultivars, Saeilmi and Baegjinju. Individual F2 plants were classified as wild type (translucent grain) and mutant type (dull grain) based on the grain appearance of brown rice. Two hundred F2 plants were segregated into 155 wild type plants and 45 mutant type plants, which fit the 3:1 ratio (
In chronic renal failure, to reduce the burden on the kidneys, it is necessary to provide patients with therapy based on a low-protein diet. To cope with this situation, low and easy to-digest protein rice variety is helpful. ‘Geongyang2’, low glutelins rice cultivar, was developed by the National Institute of Crop Science (NICS), RDA, Miryang, Korea in 2012. ‘Geongyang2’was derived from a cross between ‘Junambyeo’and‘Chugoku 173’ as a source of low glutelin and amylose. The pedigree of ‘Geongyang2’was YR24174-B-B-B-B-46 and designated as the ‘Milyang262’ in 2009. The local adaptability test of ‘Milyang262’ was carried out at six locations from 2010 to 2012. ‘Geongyang2’ is a mid-maturing ecotype with 65cm in culm length and the number of spikelet/panicle and 1,000 grain weight of brown rice were slightly lower compared to those of ‘Nampyeongbyeo’. ‘Geongyang2’ is resistant to bacterial blight and virus disease while susceptible to major insect and pest. The glutelin and amylose contents of ‘Geongyang2’ were 63.1% and 11.5%, respectively. The milled rice yield of ‘Gyeongyang2’ is 4.61MT/ha at the ordinary transplanting of the local adaptability test. This cultivar would be adaptable to the plain paddy field of middle, honam and yeongnam province of Korea under ordinary cropping system.
‘Jinsang’ is a new japonica rice variety was derived from a cross between ‘Yumetsukushi’ as a high grain quality and ‘Milky queen’ with low amylose content and good eating quality in 2000, and selected by pedigree breeding method until M8 generation. As a result, a promising line, JCH33M-15-1-9-1-5-1-1-1, was advanced and designated as the name of ‘HJ-2’ in 2009. This variety has about 111 days to heading after sowing and has 75.2 cm culm height. Milled rice of that shows dull and medium short grain and 1,000-grain weight was about 20.9 g. It has low amylose content of 11.9% and lower protein content of 6.8%. The yield potential of ‘Jinsang’ in brown rice was about 4.57 MT/ha by ordinary culture in replicated yield trial test.