• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.134-142
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• 1991

Since IR8, the first high-yielding rice cultivar characterised by semidwarf and high-tillering, was released in 1966, rice yields during the last two decades have apparently reached a plateau and subsequent efforts to further improve yielding ability have not resulted in visible gains. At this point of time, a new ideotype of rice plant would be necessary to increase grain yield potential. This experiment was conducted to investigate the yield contribution of different tillers within a plant in relation to an ideo type of rice plant. A low-tillering, large panicled IR25588 was compared with a high-tillering, small panicled IR58. Based on spikelet number and grain weight per panicle, the top six panicles in both low- and high-tillering cultivarswere significantly bigger than those in the other panicles. The top six panicles were M, PI, P2, P3, P4 and S1P2 in both cultivars. Their tillers had 100% probability of occurring. The top six tillers were characterised by earlier initiation and heading, longer growth duration, greater leaf area. and heavier culm and total dry weight per tiller. The top six panicles, based on grain weight was mainly due to higher spikelet number per panicle with little differences in 1,000 grain weight and percent fertility. They had also a greater number of high -density grains. The top six panicles were significantly bigger than the rest of the panicles in both low- and high-tilliering types suggesting that a new rice ideotype having six or fewer potential tillers or panicles per paint with 200 to 250 spikelets per panicle (a low-tillering, paicle weight type) may help increase grain yield potential since they have been shown to be superior physio-morphologically to the rest of the tillers.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.13-13
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• 2022

Recently, stable crop production is threatened by the effects of climate change. In particular, it is difficult to consistently maintain agricultural policies due to large price fluctuations depending on the difference in total domestic rice production from year to year. For stable rice production amid changes in the crop growing environment, development of varieties with improved disease resistance and abiotic stress stability is becoming more important. In here, drought and cold tolerant trait have been studied. First, for the development of drought tolerant varieties, we analyzed which agricultural traits are mainly affected by domestic drought conditions. As a result, it was observed that drought caused by the lack of water during transplanting season inhibits the development of the number of tiller and reduces the yield. 'Samgang' was selected as a useful genetic resource with strong drought tolerant and stable tiller number development even under drought conditions by phenotype screening. Three of drought tolerant QTLs were identified using doubled haploid (DH) population derived from a cross between Nacdong and Samgang, a drought sensitive and a tolerant, respectively. Among these QTLs, when qVDT2 and qVDTl1 were integrated, it was investigated that the tiller number development was relatively stable in the rainfed paddy field conditions. It is known that the high-yielding Tongil-type cultivars are severely affected by cold stress throughout the entire growth stage. In this study, we established conditions that can test the cold tolerance phenotype with alternate temperature to treat low temperatures in indoor growth conditions similar to those in field conditions at seedling stage. Three cold tolerant QTLs were explored using population derived from a cross between Hanareum2 (cold sensitive variety, Tongil-type) and Unkwang (cold tolerant variety, Japonica). Among these QTLs, qSCT12 showed strong cold tolerant phenotype, and when all of three QTLs were integrated, it was investigated that cold tolerant score was relatively similar to its donor parent, Unkwang, in our experimental conditions. We are performing that development of new variety with improved cold tolerant through the introduction of these QTLs.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.635-639
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• 2009

A new peanut variety "Pungan"(Arachis hypogaea ssp. hypogaea L.) was developed at the Department of Functional Crop, NICS(National Institute of Crop Science), in Milyang in 2008. It was developed from the cross between the high-yielding cultivar "Saedl" and the very short stem cultivar "Satonoka". "Pungan", a Virginia palnt type, has 20 branches with long ellipseshaped large grains. The 100 grain weight was 88 g, 7 g heavier than the check variety Daekwang. This variety is more resistant to late leaf spot and web blotch compared to Daekwang, a check variety. Moreover, it is lodging resistant owing to its short stem. "Pungsan" outyielded the check variety by 16% with 4.67 MT/ha in regional yield trials.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.576-580
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• 2011

'Keunseom', a new second generation Tongil-type rice variety (Oryza sativa L.), is a mid-maturing ecotype developed by the rice breeding team of Department of Functional Crop, NICS, RDA in 2006. This variety was originated from a cross between 'Dasanbyeo' and 'Namyeongbyeo' in 1996's summer season, which developed by pedigree breeding method. The pedigree of 'Keunseom' was YR18234-B-B-98-3-5-1, and it was designated 'Milyang202' in 2002. 'Keunseom' has tolerance to lodging, because it has short culm length as 77 cm. This variety is resistance to bacterial blight K1 race, rice stripe virus, rice dwarf virus, and leaf blast disease. Milled rice kernel of 'Keunseom' is a clean translucent with non-glutinous endosperm, and has good quality as it was clear in chalkness. The milled rice yield potential of 'Keunseom' was about 719 kg/10a at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to the mid and southern plain of Republic of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.503-514
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• 1997

The morphogenesis of panicle and spikelet in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in $5000^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicle of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage until heading stage. Although the date of panicle differentiation and heading in Koshihikari earlier than those of Milyang 23. the sequence of panicle development in two cultivars begins when first bract primordium at opposite side of flag-leaf primordium differentiated, synchronously followed by growth of the primary branch primordia (PBPs) and secondary branch primordia (SBPs), spikelet primordia(SPs), glumes as lateral organs on rachilla and organs composing single floret, and successive sporogenesis in the young spikelets continue after the enclosure by lemma and palea. The PBPs are acropetally initiated from the base of the panicle primordium, and the SBPs alternately differentiate from the base of upper PBP which differentiate later than the lower PBP. Spikelet development starts at the top of upper side PBP of the young panicle and continue basipetally even though SBPs continue to develop at the lower primary branch. Each PBP, SBP and SP differentiate with differentiation bract or bract hair cell around the base of each their primordia. The observation could confirm that Milyang 23 has not only 2~3 more defferentiated PBPs, but also more SBPs and SPs especially from middle-lower primary branch, at end of their differentiation stages, as compared to those of Koshihikari.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.361-365
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• 2000

This study was carried out to evaluate yearly variation and stability of yield and yield components of fifteen rice varieties. Yield stability and universal variety parameter of rice varieties were utilized for statistical model developed by Stroike, Grafius, and Finlay respectively. The lowest yearly variation based on coefficient of variation was found in Dasanbyeo for number of panicles/hill, in Jodongji for number of grains/panicle, in Yongmoonbyeo for ripened grain ratio, in Nagdongbyeo for 1,000 grain weight, and in Dasanbyeo for grain yield. Stability analysis by Stroike and Johnson's model revealed that Ilpumbyeo, Hwaseongbyeo, Dongjinbyeo in Japonica type, and And-abyeo and Dasanbyeo in Tongil type had the higher stability above average. Universal varieties analyzed by Grafius model were Ilpumbyeo, Dongjinbyeo, Hwaseongbyeo, Nagdongbyeo, and Jodongji in Japonica, and Dasanbyeo and Samgangbyeo in Tongil type. Damageum, Dongjinbyeo, Hwaseongbyeo and Ilpumbyeo in Japonica, and Dasanbyeo and Yongmoonbyeo in Tongil type were found to be highly stable as analyzed by Finlay ＆ Wilkinson's model. In conclusion, with reference to both grain yield and stability based on above three methods, Ilpumbyeo, Hwaseongbyeo, and Dongjinbyeo in Japonica, and Dasanbyeo in Tongil type were evaluated to be highly year-stable and high-yielding.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.300-300
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• 2017

'Saemimyeon' a Tongil-type rice variety (Indica ${\times}$ Japonica), which contains high amylose contents is suitable for rice noodle production. Nowadays, the major parts of rice processing industry that includes products like rice flour and noodles are expected to partially replace wheat flour market. The volume of rice noodle market is getting bigger and can contribute to the rice surplus and farmer's income. This study was carried out to promote productivity and flour-making quality of 'Saemimyeon' by finding the most suitable transplanting and harvesting times. The transplanting days used were May $10^{th}$, May $17^{th}$, May $24^{th}$, May $31^{th}$, June $7^{th}$ and June $14^{th}$ and the planting distance used was 30 x 12cm. In addition, harvesting time was determined by days after heading time (40, 45, 50, 55 and 60 days). The field experiment was conducted at the experimental field in Miryang (Southern plain area of Korea) from 2015 to 2016. Our results suggest that the optimum transplanting days were from May $24^{th}$ to May $31^{th}$ which resulted to an average yield of 748~751kg/10a. Interestingly, yield was sharply decreased below 700kg/10a before May $10^{th}$ and after June $7^{th}$. The average grain filling rate before May $31^{th}$ was more than 83% but it declined to 75% after June $7^{th}$. The average temperature ranges from heading time to harvesting time was $ 21\sim25^{\circ}C$ and the estimated optimal temperature was $23.4^{\circ}C$ which is similar to May $24^{th}$ by regression equation. We found that the optimal harvest time was 45~50 days after heading time. It is hypothesized that low temperature at seed maturation time caused the lower grain filling rate therefore 'Saemimyeon' need to be transplanted before May $31^{th}$ for higher productivity. We found no statistical variation in amylose contents among experimental plots (28.2~30.4%). We conclude that the productivity of 'Saemimyeon' highly depends on temperature that is critical for grain filling stage controlled by transplanting time.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.184-189
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• 2011

'Younghan' (Hordeum vulgare L.), a winter barley for forage use, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, Rural Development Administration in 2008. It was derived from a cross between $F_1$['YB3433-3B-5'/'YB3135-3B-2-3'] and 'YB3135-3B-2-3'. 'SB971305-B-B-B-4-4' line was selected for its earliness, resistance to disease and good agronomic characteristics. The promising line showed both high yield and lodging resistance in the yield trials in Iksan in 2004 to 2005, and designated as 'Iksan420'. The line was subsequently evaluated for winter hardiness, earliness, and yield at eight locations throughout Korea for two years from 2007 to 2008 and finally named as 'Younghan'. It has the growth habit of IV, erect plant type, green leaf and thick culm in diameter. Its heading date was April 24, and the maturing date was May 25 in paddy field conditions, which were one day earlier than those of the check cultivar 'Youngyang'. The cultivar 'Younghan' had better winter hardiness, and resistance to lodging and BaYMV than those of the check cultivar did. The average forage dry matter yield of 'Younghan' was approximately 12.0 MT/ha in adapted region. 'Younghan' also showed 8.5% of crude protein content, 27.2% of ADF, and 67.1% of TDN, including higher grade of silage quality for whole crop barley. This cultivar would be suitable for (area with daily minimum temperature in January) above $-8^{\circ}C$ in Korean peninsula.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.1-6
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• 1975

From the cross Tongil$^2//IR833/IR1317$ glutinouse rice lines wx 126 were bred. Some of these lines were earlier than standard variety and later than glutinous check variety. Some of them yielded as much as standard variety and showed better resostances to blast, stripe deseases and smaller brown plant hopper than standard variety. It was sosscussed that, theough the vreedong procedure, following points were proved, 1)back-cross program in roce breeding was effocoent, 2)semi-dwarf plant type of "Tongil" has high yielding poteneoality and 3) the variety "Tongil" was a good for recurrent parent for back-cross program. back-cross program.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.538-542
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• 2011

A new malting barley variety, 'Baegho', was developed from a cross between Azuma Golden and Nishinochikara in 1998. An elite line, YMB2139-2B-1-10-2, was selected in 2005 and designated as Milyang137. It showed good agronomic performance in the regional adaptation yield trials (RYT) from 2006 to 2008 and was released with the name of 'Baegho' having high yielding and BaYMV and powdery mildew resistance. The average heading and maturing dates of 'Baegho' were April 21 and May 28, which were 3 and 2 day later than those of Hopum, check variety, at the RYT, respectively. 'Baegho' has shoter culm length (78 cm), more spikes ($1,062per\;m^2$) and heavier 1,000 grain weight (40.7 g) than those of Hopum, respectively. 'Baegho' is resistant to domestic BaYMV strains I, III and IV and powdery mildew at Iksan. In growth habit, 'Baegho' is close to type (IV) that is distinguished from other Korean malting barley cultivars, which could tolerant to premature heading damage that is major concern for the practice of the malting barley cropping. The yield potential of 'Baegho' in the RYT was about 5.57 MT/ha, which is about 13% higher than those of Hopum. This variety has good malting quality in grain and malting analysis showed better 1,000 grain weight, husk rate, diastatic power than those of Hopum. 'Baegho' applied for protection of new varieties of plant in 2009.