• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.24-30
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• 1987

To investigate suitable breeding system for the improvement of economic characters of the sexlimited dark egg colour strains, the four kinds of breeding methods which are represented as sibmating, repeated backcrossing, multi-backcrossing every other generation, and repeated hybridization were detected from the P to the F6. 1. Pupation ratio was varied between the four kinds of breeding methods and decreased gradually in order of repeated hybridization, mult-backcrossing every other generation and sib-matinv, and repeated backcrossing. 2. Repeated backcrossing, multi-backcrossing every other generation, and repeated hybridization with the exception of sib-mating were consiered as available breeding methods to improve single cocoon weight, cocoon shell weight and cocoon shell ratio of the sex-limited dark egg colour strains. 3. As for the responses of the economic characters form the P to the F6, pupation ratio was fluctuant and unstable, on the other hand single cocoon weight, cocoon shell weight and cocoon shell ratio increased remarkably in the F2, but in the subsequant generatios the increasing rate of each characters were fluctuant irregularly. 4. After the original sex-limited dark egg colour strains were bred under the corresponding breeding methods, from the P to the F6 the economic characters were approached to the level of normal breeding silkworm lines'. 5. It came to the consideration that the autosomal fragment which was translocated on the W chromosome had no physiologically significant effect on the expression of the economic characters because the Expression index (E) of the sex-limited dark egg colour strains was similar to that of normal silkworm lines. 6. From the results, it comes to the conclusion that the useful breeding methods to improve the economic characters of the sex-limited dark egg colour strains will be a line separation including fixation of the characters.

• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.161-165
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• 1999

The objective of this research was to find a useful genetic information for yield characteristics of tillering maize hybrids. Fls were planted under three plant densities at the experimental field of Agricultural College of Chungnam National University. The fresh yield of P1213749//FR805/IK3, FR805/IK3//Waesungri and IK/LE/FR805/IK3 was 7,862kg/10a, 8,290kg/10a and 7,746kg/10a, respectively. The fresh yield of tillering maize hybrids was higher than that of P3394 hybrids. The dry matter yield of P3394 hybrid was 1,430kg/10a with low plant density(4,800p1an1s) and that of PI213749//FR805/IK3 was 1,834kg/10a, the dry weight of FR805/IK3//Waesungri was 1,836kg/10a and that of IK/LE/FR805/IK3 was 1,810kg/10a. Grain yields per 10a of IK/LE//FR805/IK3(783kg) was the highest in 4,800plants/10a, and that of check hybrid was higher than the tillering maize hybrids in 3,600plants/10a, but grain yield per 10a of IK/LE/FR805/IK3 was 752kg, and that of P1213749/Dangjin//IK/LE(699kg) was higher than P3394 hybrid(680kg) with 2,400plants/10a.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.495-508
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• 1993

This experiment was conducted to investigate the amount of natural crossing at varying isolation distance and various transplanting time in tobacco. Normal variety and male sterile line showed an average of 1. 6 and 29% natural crossing in the adjacent plantings, respectively. The natural crossing was highest in the adjacent planting, as expected, and less at the farther distance from pollinator plants. Plants transplanted in April 20th were higher in natural crossing than those of other transplanting time.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.92-99
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• 2017

This experiment was carried out to compare the growth characteristics and productivity between sudangrass and sorghum-sudangrass hybrid under the same cultivation condition in Cheonan and Kimje of Korea from 2010 to 2011. Sudangrass hybrids(Choice, Sunstar and Piper) and sorghum-sudangrass hybrids(SX-17, Jumbo and Revolution) were planted $5^{th}$ May in Cheonan and $7^{th}$ May in Kimje. Heading date of sudangrass hybrids was $12^{th}$ July which was about 2 week fast more than that of sorghum-sudangrass hybrids. Stem diameter of sudangrass hybrids was about 6mm which was about 5 mm smaller than that of sorghum-sudangrass hybrids. Disease resistance of sudangrass hybrid, "Choice" was similar to that of sorghum-sudangrass hybrids. Dry matter yield of "Choice" was 15ton/ha which was 10% less than that for sorghum-sudangrass hybrids(SX-17). Feed value of "Choice" was similar or slightly lower than that of sorghum-sudangrass. For increasing the productivity in forage cropping systems all around year, sudangrass hybrid is recommended for prolong by the middle ten day of May in the harvesting time of italian ryegrass.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.608-618
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• 1996

Wild perennial types of genus Glycine, as sources of genetic diversity, have been recently employed in the soybean breeding programs. This study was carried out to introduce some useful characters of wild perennial Glycine tomentella into common cultivars, G. max. Parent materials used for interspecific hybridization were three common cultivars, Ulsankong, Baemkong and Danyeobkong, and four G. tomentella strains having different diploid(2n) of 38, 40, 78, and 80. Their cross-fertility, effect of reciprocal cross, development comparison of crossing pod and optimum timing to efficient crossing were investigated. Plant were grown in 1/2,000 Wagner pots in greenhouse and field. Crossing efficiency and pod survival rate were the highest in 2n=38 of the four G. tomentella strains when the common cultivars were fixed as female parents. In the reciprocal cross of three common cultivars and four G. tomentella strains, when the former was used as maternal sources, they showed better crossing rate and longer pod survival than the latter. In the interspecific hybridization between G. max cv. Baemkong andG. tomentella, 2n=38, the pod formed from the female G. tomentella had relatively greater size and weight than that from the female Baemkong in comparison with parents. However, the reverse result was true in a number of ovules per pod. More efficient interspecific hybridization in the field was made on August 20, when temperature and relative humidity were higher and day length was shorter, than one or two months earlier.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.49-49
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• 2020

본 연구는 호랑버들과 갯버들 교잡종의 잎 형태적 특성을 국내 자생종인 호랑버들, 갯버들과 비교하였다. 호랑버들 35개체, 갯버들 35개체, 교잡종 100개체에서 잎을 채취하여 잎의 길이와 너비, 엽저와 엽두 각도, 잎자루 길이와 너비, 탁엽의 길이와 너비, 잎 두께 등 총 17개의 잎 형태적 특성을 분석한 결과, 엽두 각도와 탁엽의 길이를 제외한 15개의 특성에서 세 분류군이 유의한 차이를 나타내었다. 교잡종의 잎 길이와 너비의 비는 갯버들, 교잡종, 호랑버들 순으로 크게 나타나 교잡종의 잎의 형태는 피침형인 갯버들과 타원형인 호랑버들 사이 중간 형태로 나타났다. 교잡종의 잎의 너비, 엽저 각도, 잎자루의 길이와 너비, 탁엽의 길이와 너비는 호랑버들과 갯버들의 중간 형태를 나타내었으며, 탁엽의 거치 개수는 교잡종이 호랑버들과 갯버들보다 많은 특성이 나타났다. 잎 뒷면 단위면적당 털의 개수 또한 교잡종이 호랑버들과 갯버들보다 많은 특성을 나타냈다. 세 분류군 간 잎 형태적 차이를 구명하기 위해 유의한 차이를 보인 15개의 변수를 이용하여 주성분분석을 실시한 결과 고유값이 1 이상인 제 1, 2, 3, 4주성분이 전체 분산의 68.2%를 설명하였다. 제 1주성분은 잎의 너비, 잎의 1/3 아랫부분 너비, 잎의 1/3 윗부분 너비, 잎자루의 길이, 잎의 길이로 잎의 크기와 관련이 있는 특성들이 높은 상관관계를 나타내었고, 제 2주성분은 엽맥의 수, 잎자루의 너비와 높은 상관관계를 나타내었다. 제 3주성분은 탁엽의 거치 개수, 탁엽의 너비로 탁엽의 특성과 관련이 있는 특성들이 높은 상관관계를 나타내었으며, 제 4주성분은 잎의 두께와 높은 상관관계를 나타내었다. 주성분분석 결과 호랑버들과 갯버들 교잡종의 잎 특성은 호랑버들보다 갯버들과 가까운 것으로 나타났다. 잎의 형태적 특성으로 세 분류군을 구별하기 위해 정량형질을 이용한 판별분석 결과 교잡종 중 대부분(93.3%)이 호랑버들, 갯버들과 구별되었다. 일부 교잡종 개체(6.7%)가 갯버들로 오분류되었지만, 잎의 정성적 특성인 잎의 거치와 측맥의 특성을 고려한 결과 모든 개체가 교잡종으로 구분되었다. 따라서 호랑버들과 갯버들의 교잡종은 잎의 형태적 특성이 부모종인 호랑버들, 갯버들과 다른 독특한 형태를 가진 것으로 나타났다.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.163-170
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• 2022

In this study, the results of hybridization were evaluated by analyzing the biomarkers of Haliotis discus hannai and hybrid abalone (H. madaka♀^*H. discus discus♂) in marine net cage. The survival rate was similar both experimental groups, but the growth (shell length) was about 10% faster in hybrid abalone. The deformity of respiratory pore in the hybrid abalone was about 6% lower than H. discus hannai, and the shell depression was about 15% lower in the hybrid abalone. In the biochemical composition, crude protein was about 3.1% higher in hybrid abalone, and showed similar values except for the crude protein. In the histological structure of the hepatopancreas, which performs the functions of digestion, absorption and detoxification of abalone, good results were obtained in the hybrid abalone. On these results, it is judged that the hybrid abalone will have high aquaculture productivity in the aquaculture environment.

• Journal of Mushroom
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• v.12 no.2
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• pp.96-106
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• 2014

The primary objective of the present study is the characterization of the somatic hybrids of dikaryon-monokaryon (di-mono) crosses in mushroom breeding. We employed this technique for developing superior strains from Pleurotus ostreatus strains with 48 intraspecific hybrids of 12 combinations between six P. ostreatus strains and one P. florida strain. The results on the experiments of hybridization rate, nuclear DNA patterns, and colors and morphology of fruit-bodies, are presented. In di-mono crosses, somatic hybrids among Pleurotus strains showed 100% of crossability as seen in those between P. ostreatus and P. florida strains indicating that the nuclei of a dikaryon is inferred to be migrated to a recipient. 87.5% of the somatic hybrids among Pleurotus strains were similar to the donor dikaryons, and 12.5% of the somatic hybrids presented DNA patterns of both parents. In 16.6% of di-mono crosses between P. ostreatus and P. florida, the nuclear DNA patterns of all hybrids showed the same or similar patterns compared to the donor dikaryons. 70.9% of the hybrids between P. ostreatus and P. ostreatus were similar to the donor dikaryons and 12.5% of them presented the DNA patterns of both parents. 79.2% of fruiting body morphology of the hybrids among Pleurotus strains were similar to the dikaryons and 20.8% of them were similar to both parents. Interestingly, the morphology of all dikaryons were dissimilar each other. All hybrid strains between dikaryon P. florida and monokaryon P. ostreatus showed the fruiting body of which colors were similar to those of the dikaryon, while the hybrids between dikaryon P. ostreatus and monokaryon P. florida were showed the combined colors of both parents. Therefore, the fruiting body color of P. florida tends to be generally dominant. In conclusion, the present study provides a way to find out and suggest superior hybrid strains using the nuclear DNA patterns of hybrids between Pleurotus strains as well as the characteristics of their fruiting bodies. The advantages of the di-mono crossing are needs to be fully utilized in mushroom breeding because it is an ideal way to develop the superior strains of Pleurotus.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.66-66
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• 2022

속성수로 활용되는 버드나무속 식물들은 생식기관과 영양기관의 성장 시기가 달라 형태적 특성 평가를 위해 수년간의 조사 기간이 요구된다. 따라서 바이오매스 우수 버드나무속 교잡종 육성의 성공 여부를 조기 판별하기 위한 식별 기술이 필요하다. DNA 마커는 식물의 생장단계와 관련 없이 탐색할 수 있으며 환경에 영향을 받지 않는 장점이 있다. 식물의 계통 분류 시 주로 사용되는 엽록체 DNA는 유전자 염기서열의 변이가 비교적 크지 않은 장점이 있으나 대부분의 활엽수에서 모계를 통해 유전되는 특징이 있다. 하지만 종간 교잡종의 식별은 각각의 부모종과 구분할 수 있어야 하므로 본 연구는 엽록체 DNA가 아닌 핵 DNA를 대상으로 분석하였다. 본 연구의 목적은 호랑버들을 암나무로 갯버들을 수나무로 인공교배하여 육성된 종간 교잡종을 식별하는 핵 DNA 마커를 탐색하는 것이다. 이를 위해 버드나무속에서 개발된 총 35개의 nSSR (nuclear Simple Sequence Repeat) 마커를 대상으로 호랑버들과 갯버들, 종간 교잡종의 식별 가능성을 평가하였다. 분석 결과 호랑버들과 갯버들, 종간 교잡종 간 차이를 나타내는 2개의 핵 DNA 마커를 선발하였다. 따라서 선발된 핵 DNA 마커를 활용하여 호랑버들과 갯버들, 종간 교잡종의 조기 식별에 활용이 가능할 것으로 사료된다.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.39-44
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• 2014

The goal of this study was to evaluate the growth performance of crossbred strains using Korean native chicken (KNC). The data were collected from 2012 through 2013 at Poultry Science Division, National Institute of Animal Science, Korea. The number of chicks analyzed in this study was 375. Crossbred were (A) $R{\times}S$, (B) $D{\times}H$, (C) $D{\times}S$, (D) $C{\times}Y$ and (E) $Y{\times}H$. The fertility rates of strains were 94.9% in crossbred A, 91.9% in crossbred B, 91.8% in crossbred C, 89.7% in crossbred D and 93.8% in crossbred E, respectively. The fertility was highest in crossbred A, but crossbred C showed the lowest (p<0.05) based on the hatchability. The crossbreds B and C exhibited a superior performance on body weight gains during growing stages but crossbred D showed the lowest (p<0.05). The feed intake was to the pattern of body weight. The feed intake of crossbred D was significantly lower than other crossbreds. Also, feed conversion ratio of crossbred D showed the lowest (p<0.05). Egg production ratio of crossbred D was significantly higher compared to the other crossbreds. These results suggest that the development of new crossbreds of commercial Korean Native Chickens should be required for better performance.