• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.40-49
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• 2010

This study was conducted to examine genetic variation on leaf characteristics of Zelkova serrata populations. Leaf samples were obtained from eighteen populations and fourteen leaf characteristics such as leaf blade length, leaf width, leaf area and etc. were measured. In all leaf characteristics, there were significant differences among populations and among individuals within population. Most variance of leaf characteristics was contributed to among individuals within population except for length from leaf base to maximum width (x3) and the ratio of x3 to leaf blade length (x10). The relatively high variations of leaf characteristics were found at Gurye, Jungeup and Gyungju populations while Youngwol, Cheongsong, Youngchun populations showed the lower variation. There was high correlation among leaf characteristics related to leaf size, but not among the variables of ratio between leaf characteristics. Length from leaf base to maximum width(x3) and the ratio of x3 to x10 showed significant positive correlation with latitude and altitude of populations, which reflect the differences of mean annual temperature among populations. Mean annual rainfall of populations showed negative correlation with leaf blade length, leaf width, length from apex to first serration and leaf area. Four principal components (PC) were deduced from principal component analysis, which explain the 88.5% of total variance of leaf characteristics. Leaf area, length from leaf base to maximum width, serration number and petiole length showed the highest contribution to PC1, PC2, PC3, PC4, respectively. According to cluster analysis, the populations of Z. serrata were divided into two groups, which reflect the difference of mean annual temperature between groups. Within group, however, specific tendency of clustering was not observed among populattions.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.615-622
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• 2010

A new rice cultivar, 'Joami', was developed by the rice breeding team of Sangju Substation, National Institute of Crop Science (NICS), Rural Development Administration. It was selected by a bulk and pedigree methods from a cross-combination among 'Sambaegbyeo', 'Yukara', and 'Tonggae112'. A promising line of YR20557-1-1-3-B-3 was designated as 'Sangju 36' in 2006. Local adaptability test of 'Sangju 36' was conducted at ten sites throughout the Korean peninsula during three years from 2006 to 2008. 'Sangju 36', thereafter, was registered as 'Joami' in 2008. The cultivar headed on July 30 in the test of local adaptability. Endosperm of 'Joami' is translucent with clear chalkiness and has 5.4% higher head rice ratio than that of 'Odaebyeo'. The yield potential of 'Joami' in milled rice is about 5.40 MT/ha under ordinary fertilizer level of local adaptability test, which was 6% higher than that of 'Odaebyeo'. In an alpine area of Korea, the rice variety needs a cold tolerance and a resistance to blast disease. 'Joami' showed a tolerance reaction at Chuncheon cold tolerance screening nursery and exhibited resistance reaction to blast disease in nation-wide disease screening nursery. Therefore, 'Joami' would be well adaptable to mid-mountainous area at central and southern part of Korean peninsula.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.313-317
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• 2010

There are the farmer's needs to develop early-maturing cultivar adaptable to mid-northern inland plain and alpine area. Furthermore, it is required to develop a rice variety to produce new rice before concentrated marketing dates, even in the years of early Chuseok. 'Joun' is a new extremely early-maturing japonica rice cultivar developed in 2009 from the cross of SR14880-173-3-3-2-2-2/Unbong20 at Cheolwon Substation, National Institute of Crop Science (NICS), Rural Development Administration (RDA). The heading date of 'Joun' is July 23 in mid-northern alpine area, which is 7 days earlier than that of Odaebyeo. It has about 61 cm in culm length with semi-erect plant type. Panicle has a few awns and its exertion is good. The number of spikelets per panicle is smaller than that of Odaebyeo and 1,000 grain-weight of brown rice is 21.2 g which is less than 26.3 g of Odaebyeo, but the complete grain ratio is higher. Milled kernels are translucent with non-glutinous endosperm and palatability of cooked rice is good. It shows strong resistance to cold treatment, lodging, premature heading, wilting and viviparous germination during ripening stage. This cultivar shows resistance to leaf blast disease but susceptible to bacterial blight, virus disease and insect pests. The milled rice yield performance of 'Joun' is about 5.18 MT/ha by ordinary culture in local adaptability test for three years. This cultivar may be highly adaptable to the mid-northern inland plain and alpine area, north-eastern coastal area and middle plain area.

• Food Engineering Progress
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• v.15 no.4
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• pp.404-412
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• 2011

The purpose of this study is to prepare extruded rice flours suitable for baking rice cookies. The extruded rice flours were prepared at 100 and 130$^{\circ}C$ temperature and 25 and 27% moisture content in a co-rotating twin screw extruder. The rice extrudates were dried at 100$^{\circ}C$ for 18 hr and subsequently ground into the fine flour. Characteristics of the extruded rice flours were examined by rapid visco analysis, hydration property analysis, differential scanning calorimetry (DSC), and in vitro digestion test. Water absorption, solubility, and swelling power of all extruded rice flours were higher than those of native rice flour. DSC analysis showed that native rice flour had a peak at about 65$^{\circ}C$ while all extruded rice flours did not show any peaks since they were already gelatinized during the extrusion proess. Viscosity of the extruded rice flours decreased with increasing temperature and lowering moisture content in the extrusion proess. The extruded rice flours prepared at 130$^{\circ}C$ exhibited lower viscosity than those prepared at 100$^{\circ}C$. The operating temperature of the extrusion proess was critical for the starch digestion in vitro. The extruded rice flours prepared at 130$^{\circ}C$ showed a rapid decrease in digestible starch content while an increased level of slowly digestible starch content was observed compared to those treated at 100$^{\circ}C$ in the extruder. Cookies were prepared with a mixture of wheat flour and extruded rice flours at the ratio of 7 to 3. The cookies made with the extruded rice flours had lower spread factor and darker yellow color than those prepared with wheat flour only. Hardness of the extruded rice flour-added cookies was similar to that of the wheat flour cookie whereas their overall acceptance was better. Therefore the rice cookies partially supplemented with extruded rice flours may have a potential as early childhood foods which require soft texture and allergy reduction.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.262-266
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• 2010

'Josaengheugchal', a new blackish purple pigmented glutinous japonica rice cultivar, was developed by the rice breeding team of Department of Functional Crop, NICS, RDA in 2004. This cultivar was derived from a cross between 'Tohoku 149' as black glutinous source and 'Sx 864' as purple colored rice in 1992 and 1993 winter season, and selected by pedigree breeding method until $F_6$ generation. As a result, a promising line, YR15907-6-8-1-5, was advanced and designated as the name of 'Milyang 194' in 2001. The local adaptability test of 'Milyang 194' was carried out at seven locations from 2002 to 2004 and it was named as 'Josaengheugchal'. 'Josaengheugchal' is an early maturing cultivar and has 71 cm culm height. It has higher anthocyanian content compared with 'Heugnambyeo'. It is moderately resistant to leaf blast but susceptible to other disease and insect pests. The yield potential of 'Josaengheugchal' in brown rice was about 4.21 MT/ha at ordinary fertilizer level in local adaptability test. This cultivar would be adaptable to the plain paddy field of middle, Honam, and Yeomgnam in Korea under ordinary and double cropping system.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.272-275
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• 2010

'Geumyoung' is a new early maturing rice cultivar developed from the cross between Sambaegbyeo and Iksan423/Sangju22 at Sangju Substation, NICS, RDA, Korea in 2009. It needs about 116 days from seedling to harvest in mid-mountainous areas. This cultivar has about 72 cm long culm and 19 cm long panicle, which are similar to Odaebyeo. It has higher panicle number per plant, medium to small grains and sometimes has a few awned spikelets. It shows tolerance to cold and resistance to blast but is susceptible to bacterial blight, virus diseases, and insects and pests. Milled rice of 'Geumyoeng' is translucent with non-glutinous endosperm and medium short grain. It has about 18.0% amylose and 6.6% protein content with good palatability of cooked rice. The milled rice yield of this cultivar was 5.53 MT/ha under standard fertilizer level of ordinary transplanting cultivation. 'Geumyong' would be adaptable for ordinary transplanting cultivation in the northern plains, and northern and southern mid-mountainous areas of South Korea.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.397-406
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• 2010

Field screening method has been commonly used for purity test of $F_1$ hybrid seeds in melon and oriental melon. However, as this method takes a lot of time and cost, molecular marker-based purity test is necessary. To develop molecular markers for purity test, thirty pairs of SNP (single nucleotide polymorphism) primers were obtained from melon EST sequences, and 10 polymorphic markers showing HRM (high resolution melting) polymorphisms between parents of two melon cultivars and one oriental melon cultivar were selected. Blind tests were performed to validate usefulness of the selected markers for purity test. Blind test results showed that HRM genotypes were matched with the expected identity of individual sample, $F_1$ hybrid, male or female parents. Three HRM-based SNP markers were converted to CAPS markers for general use which is favor to breeders. We expect that SNP markers developed in this study will be useful for purity test of $F_1$ hybrid seeds in melon and oriental melon.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.554-558
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• 2011

A single cross hybrid, 'Eolrukchal 1', is a bicolor waxy corn (Zea mays L.) developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2007. This hybrid, which has a high eating quality, was produced by crossing two inbred lines, KBW23 and KW33. KBW23 was a seed parent and KW33 was a the pollen parent of 'Eolrukchal 1'. Ear length and diameter of 'Eolrukchal 1' is 18.4 cm and 4.5 cm, respectively. The ratio of kernel set length/ear length is 89%, similar with that of a check hybrid, 'Chalok 1'. It is resistant to Exserohilum turcicum (Northern corn leaf blight) and its lodging resistance is higher than that of 'Chalok 1'. The yield of 'Eolrukchal 1' in fresh ear weight was 9.80 ton/ha and 14% higher than that of 'Chalok 1' in regional yield trials (RYT) from 2005 to 2007. A seed production of this hybrid has been well due to good match during crossing between the seed and the pollen parents. It is adaptable to the whole country except Jeju-do.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.627-631
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• 2010

A new cultivar of lettuce (Lactuca sativa L.) with wrinkled traverse elliptic and deep red leaf, 'Chunpungjeokchukmyeon' which has late bolting and deep red expression leaf color was developed from a cross between 'Pojabijeokchukmyeon' (red leaf color and late bolting) and 'Meokchima' (Deep red and low yield). The cross and selection for advanced lines had been done by the pedigree method during 2000-2007. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) from 2008 to 2009. The 'Chunpungjeokchukmyeon' has gray seed color and traverse elliptic leaves. The type of matured stage is medium shape between 'chukmyeon' and 'chima' leaf lettuce. Compared to 'Dukseomjeokchukmyeon', marketable yield of 'Chunpungjeokchukmyeon' was higher by 6% (at 372 g per plant) and 'Chunpungjeokchukmyeon' has particularly improved expression of deep red leaf color in high temperature cultivation in the field. The shelf-life of 'Chunpungjeokchukmyeon' was three weeks longer than 'Dukseomjeokchukmyeon' at 4$^{\circ}C$. The anthocyanin content of 'Chunpungjeokchukmyeon' was higher than that of 'Dukseomjeokchukmyeon' with 17.5 mg/100g. The BSL (latucin+8-deoxylactucin+lactucopicrin) content of 'Chunpungjeokchukmyeon' is lower than that of 'Dukseomjeokchukmyeon'. Furthermore, its taste is better, more crispy, and sweeter than those of 'Dukseomjeokchukmyeon'. So we recommend that new cultivar 'Chunpungjeokchukmyeon' can be suitable for cultivation in spring season than summer season.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.430-441
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• 2011

Maize is divided into two types based on the starch composition of the endosperm in the seed, normal maize(or non-waxy maize) and waxy maize. In this study, genetic diversity and population structure were investigated among 80 waxy maize and normal inbred lines(40 waxy maize inbred lines and 40 normal maize inbred lines) using 50 SSR markers. A total of 242 alleles were identified at all the loci with an average of 4.84 and a range between 2 and 9 alleles per locus. The gene diversity values varied from 0.420 to 0.854 with an average of 0.654. The PIC values varied from 0.332 to 0.838 with an average of 0.602. To evaluate the population structure, STRUCTURE 2.2 program was employed to confirm genetic structure. The 80 waxy and normal maize inbred lines were separated with based on the membership probability threshold 0.8, and divided into groups I, II and admixed group. The 13 waxy maize inbred lines were assigned to group I. The 45 maize inbred lines including 7 waxy maize inbred lines and 38 normal maize inbred lines were assigned to group II. The 22 maize inbred lines with 20 waxy maize inbred lines and 2 normal maize inbred lines were contained in the admixed group. The cluster tree generated using the described SSR markers recognized three major groups at 31.7% genetic similarity. Group I included 40 waxy maize inbred lines and 11 normal maize inbred lines, and Group II included 27 normal maize inbred lines. Group III consist of only 2 normal maize inbred lines. The present study has demonstrated the utility of SSR analysis for the study of genetic diversity and the population structure among waxy and normal maize inbred lines. The information obtained from the present studies would be very useful for designing efficient maize breeding programs in Maize Experiment Station, Kangwon Agricultural Research and Extension Services.