• Plant Breeding and Biotechnology
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• 제7권3호
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• pp.272-286
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• 2019

Developing elite hybrid rice varieties is one important objective of rice breeding programs. Several genes related to male sterilities, restores, and pollinators have been identified through map-based gene cloning within natural variations of rice. These identified genes are good targets for introducing genetic traits in molecular breeding. This study was conducted to breed elite hybrid lines with major genes related to hybrid traits and disease/insect resistance in 240 genetic resources and F₁ hybrid combinations of rice. Molecular markers were reset for three major hybrid genes (S5, Rf3, Rf4) and thirteen disease/insect resistant genes (rice bacterial blight resistance genes Xa3, Xa4, xa5, Xa7, xa13, Xa21; blast resistance genes Pita, Pib, Pi5, Pii; brown planthopper resistant genes Bph18(t) and tungro virus resistance gene tsv1). Genotypes were then analyzed using molecular marker-assisted selection (MAS). Biological assay was then performed at the Red River Delta region in Vietnam using eleven F₁ hybrid combinations and two control vatieties. Results showed that nine F₁ hybrid combinations were highly resistant to rice bacterial blight and blast. Finally, eight F₁ hybrid rice varieties with resistance to disease/insect were selected from eleven F₁ hybrid combinations. Their characteristics such as agricultural traits and yields were then investigated. These F₁ hybrid rice varieties developed with major genes related to hybrid traits and disease/insect resistant genes could be useful for hybrid breeding programs to achieve high yield with biotic and abiotic resistance.

• Journal of Plant Biotechnology
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• 제46권3호
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• pp.165-171
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• 2019

Marker-assisted backcrossing (MABC)은 marker-assisted selection (MAS)와 함께 다양한 작물에서 여교배 초기세대에서 반복친 게놈의 회복률이 높은 개체선발을 위한 분자육종 기술로 매우 유용하게 사용하고 있다. 본 연구에서는 토마토 MABC 육종 프로그램의 일환으로 저장성이 강한 rin유전자를 주)토마토연구소에서 육성한 핑크계 엘리트 토마토계통에 도입하고자 수행하였다. foreground 선발은 RIN SCAR 분자 마커를 이용하여 100개 $BC_1F_1$ 식물체에서 Rr 유전자형 가진 42개체를 선발하였다. 그리고 이를 이용하여 GBS 분석을 이용하여 background 선발을 하였다. 총 3,086개 SNP를 대상으로 반복친 HK13-1151과 게놈 회복률을 조사한 결과, 56.7%에서 84.5%를 보여 평균 70.5%로 나타났다. 이 중 87.2%을 보인 $BC_1F_1$개체를 이용하여 192개 $BC_2F_1$ 식물체를 육성하여 foreground 선발을 하였다. 선발된 102개 중 88개 식물체를 이용하여 GBS 분석을 수행한 결과 4,868개의 다형 SNP 마커를 얻었으며, 이를 이용하여 RPG 회복률을 조사하였다. $BC_2F_1$ 식물체들에서 HK13-1151 반복친 게놈과 87.8%에서 97.8% 유사하였다. 본 연구에서 $BC_2F_1$ 식물 중 RPG 회복률이 97.8%인 5-1 개체는 반복친인 HK13-1151과 과일특성에서 매우 유사하였다. 따라서 선발된 5-1 개체는 $BC_2F_2$ 세대를 육성하여 계통화 하고자 한다. 본 연구를 통해 MABC는 전통 여교배 육종에 비해 육종연한을 획기적으로 줄일 수 있으며, 원하는 육종모델을 완수할 수 있는 첨단육종 기술로 평가 할 수 있다.

• Molecules and Cells
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• 제26권6호
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• pp.548-553
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• 2008

The erect habit of fruit setting is a unique characteristic of ornamental peppers and wild pepper species. The erect habit is known to be controlled by the up locus on pepper (Capsicum annuum L.) chromosome 12. The result of a genetic analysis using Saengryeog 211 (pendant), Saengryeog 213 (erect), and their $F_1$ and $BC_1$ progeny demonstrated that up is a recessive gene. To develop an up-linked marker, bulked segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) were employed using 108 $F_{2:3}$ individuals. The closest AFLP marker, $A2C7_{469}$, was located at a genetic distance of 1.7 cM from the up locus and was converted into a cleaved amplified polymorphic sequence (CAPS) marker. This marker was mapped at a genetic distance of 4.3 cM from the up locus. When the CAPS was applied to seven ornamental lines and 27 breeding lines with erect fruit, these genotypes of 28 lines were correctly predicted. Thus, the CAPS marker will be useful for marker-assisted selection (MAS) of pepper breeding lines with the up allele at the early seedling stage.

• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.172-177
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• 2007

Thyroid hormones play an important role in regulating metabolism and can affect homeostasis of fat depots. The gene encoding thyroglobulin (TG), producing the precursor for thyroid hormones, has been proposed as a positional and functional candidate gene for a QTL with an effect on fat deposition. The SNP occurs in the 5' promoter region of the TG gene and is widely used in marker assisted selection (MAS) programs to improve the predictability of marbling level and eating quality in beef cattle. In this study, we identified three SNPs at the 5' promoter region of the TG gene in Korean cattle. Of the three SNPs identified in TG gene, the C257T and A335G were previously unreported new SNPs. The sequence data were submitted to GenBank (GenBank accession number: AY615525). The previously reported C422T SNP showed three genotypes, CC, CT and TT, by digestion with the restriction enzyme MflI using the PCR-RFLP method. A new allelic variant corresponding to the C${\rightarrow}$T and A${\rightarrow}$G mutations at positions 257 and 335, respectively, could be detected by the SSCP analysis. The gene-specific SNP marker association analysis indicated that the C422T SNP marker was significantly associated (p<0.05) with marbling score. Animals with the CC and CT genotypes had higher marbling score than those with the TT genotype. Results from this study suggest that TG gene-specific SNP may be a useful marker for meat quality traits in future MAS programs in Korean cattle.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.233-233
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• 2022

As the world's population grows and food needs diversify, the demand for horticultural crops for beneficial traits is increasing. In order to meet this demand, it is necessary to develop suitable cultivars and breeding methods accordingly. Breeding methods have changed over time. With the recent development of sequencing technology, the concept of genomic selection (GS) has emerged as large-scale genome information can be used. GS shows good predictive ability even for quantitative traits by using various markers, breaking away from the limitations of Marker Assisted Selection (MAS). Moreover, GS using machine learning (ML) and deep learning (DL) has been studied recently. In this study, we aim to build a system that selects phenotype-related markers using the genomic information of the pepper population and trains a genomic selection model to select individuals from the validation population. We plan to establish an optimal genome wide association analysis model by comparing and analyzing five models. Validation of molecular markers by applying linkage markers discovered through genome wide association analysis to breeding populations. Finally, we plan to establish an optimal genome selection model by comparing and analyzing 12 genome selection models. Then We will use the genome selection model of the learning group in the breeding group to verify the prediction accuracy and discover a prediction model.

• 한국육종학회지
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• 제43권5호
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• pp.413-421
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• 2011

본 연구에서는 관행의 교배육종과 DNA 마커를 이용한 MAS의 접목을 통하여 벼멸구 저항성과 관련된 단점을 보완하고, 효율적으로 도열병, 줄무늬잎마름병, 흰잎마름병, 벼멸구, 끝동매미충 저항성이 집적된 복합내병충성 우량계통을 육성하고자 수행하였다. 교배모본으로는 완전미율이 높고, 끝동매미충에 저항성인 '남평'과 단간이면서 흰잎마름병에 저항성인 '주남'을 반복친으로 사용하였고, 벼멸구저항성 유전자 Bph1을 가지고 있지만 간장이 크고 재배안전성이 미흡한 '밀양220호'를 공여친으로 사용하였다. 벼멸구 저항성 연관마커 RM28493을 이용하여 $BC_1F_1$ 및 $BC_2F_1$ 세대에서 MAS로 저항성 개체 선발과 여교잡을 수행하였으며, 복교잡 $F_1$ 세대에서 MAS를 통한 벼멸구 저항성이 고정된 계통을 선발하였다. 고세대 계통에서 생물검정을 통하여 흰잎마름병, 끝동매미충에 저항성인 계통을 선발하였다. MAS와 생물검정을 통해 도열병, 흰잎마름병, 줄무늬잎마름병, 벼멸구 및 끝동매미충에 저항성인 85개의 복합내병충성계통을 선발하였다. 복합내병충성 계통의 간장, 완전미율 및 수량은 각각 71~88 cm, 51~93%, 449~629 kg/10a 사이에 분포하였다. 복합내충성계통중 간장, 완전미율 및 수량이 남평벼와 비슷한 계통을 선발하여 '밀양265호'로 명명하였다. 최종적으로 본연구에서는 기존의 교배육종과 분자육종의 접목을 통하여 복합내병충성 우량계통을 육성하였으며, 이는 금후 유용교배모본으로 활용될 것으로 기대된다.

• 한국육종학회지
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• 제41권4호
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• pp.568-573
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• 2009

신강은 콩나물 적성이 뛰어나고 농업형질이 우수하나 콩모자이크병에 약한 소원콩을 반복친으로, 콩모자이크병 저항성 유전자 Rsv3을 보유한 L29를 일회친으로 사용하여 육성된 품종이다. 육성기간의 단축을 위하여 분자표지선발법을 사용하여 목표유전자의 도입과 반복친의 회복정도를 신속히 확인함으로써 품종 개발에 소요되는 기간을 7년으로 단축하였다. 신강의 주요 특성을 요약하면 다음과 같다. 1. 유한신육형이며, 꽃색은 자색이고 엽형은 피침형이다. 입형은 구형이고 종피색은 황색, 배꼽색은 담갈색이며 100립중은 11.0 g으로 다소 가볍다. 2. 개화기는 7월 30일, 성숙기는 10월 7일로 풍산나물콩에 비하여 다소 빠른 중만생종이다. 3. 콩 모자이크병, 미이라병 및 노균병에 대해 강한 저항성을 보였다. 4. 콩나물 재배 특성으로는 부패립 발생이 거의 없고, 콩나물 수율은 635%로 풍산나물콩에 비해 다소 높다. 5. 3개년간의 지역적응시험 결과 풍산나물콩 대비 동등한 수량을 나타내었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.235-235
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• 2022

Genome selection is a promising tool for plant and animal breeding, which uses genome-wide molecular marker data to capture large and small effect quantitative trait loci and predict the genetic value of selection candidates. Genomic selection has been shown previously to have higher prediction accuracies than conventional marker-assisted selection (MAS) for quantitative traits. In this study, the prediction accuracy of 10 agricultural traits in the wheat core group with 567 points was compared. We used a cross-validation approach to train and validate prediction accuracy to evaluate the effects of training population size and training model.As for the prediction accuracy according to the model, the prediction accuracy of 0.4 or more was evaluated except for the SVN model among the 6 models (GBLUP, LASSO, BayseA, RKHS, SVN, RF) used in most all traits. For traits such as days to heading and days to maturity, the prediction accuracy was very high, over 0.8. As for the prediction accuracy according to the training group, the prediction accuracy increased as the number of training groups increased in all traits. It was confirmed that the prediction accuracy was different in the training population according to the genetic composition regardless of the number. All training models were verified through 5-fold cross-validation. To verify the prediction ability of the training population of the wheat core collection, we compared the actual phenotype and genomic estimated breeding value using 35 breeding population. In fact, out of 10 individuals with the fastest days to heading, 5 individuals were selected through genomic selection, and 6 individuals were selected through genomic selection out of the 10 individuals with the slowest days to heading. Therefore, we confirmed the possibility of selecting individuals according to traits with only the genotype for a shorter period of time through genomic selection.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.523-528
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• 2003

본 연구는 PvuII PCR-RFLP를 이용하여 Yorkshire종 돼지에서 Estrogen Receptor의 유전적 다형과 산자수간의 관련성을 분석하기 위하여 수행되었다. 무창 돈사에서 사육중인 242두의 종빈돈으로부터 혈액을 채취하여 PvuII PCR- RFLP로 ER 유전자형을 결정하였다. ER 유전자 좌위에서 유전자 빈도는 각각 0.39(A)와 0.61(B)였다. ER 유전자형별 산자수에 대한 효과는 최소제곱평균을 설명하는 고정모형을 설정하여 추정하였다. 분석결과 복당 총산자수와 실산자수에서 특정 ER 대립유전자(B)에서 산자수 증진효과가 관찰되었다. 따라서 돼지 ER 좌위의 유전적 변이는 번식돈의 산자수 증대와 관련된 marker-assisted selection(MAS)에 응용될 수 있을 것으로 사료된다.

• Molecules and Cells
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• 제23권2호
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• pp.192-197
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• 2007

Bulb color in onions (Allium cepa) is an important trait whose complex inheritance mechanism involves epistatic interactions among major color-related loci. Recent studies revealed that inactivation of dihydroflavonol 4-reductase (DFR) in the anthocyanin synthesis pathway was responsible for the color differences between yellow and red onions, and two recessive alleles of the anthocyanidin synthase (ANS) gene were responsible for a pink bulb color. Based on mutations in the recessive alleles of these two genes, PCR-based markers for allelic selection were developed. In this study, genotype analysis of onions from segregating populations was carried out using these PCR-based markers. Segregating populations were derived from the cross between yellow and red onions. Five yellow and thirteen pink bulbs from one segregating breeding line were genotyped for the two genes. Four pink bulbs were heterozygous for the DFR gene, which explains the continuous segregation of yellow and pink colors in this line. Most pink onions were homozygous recessive for the ANS gene, except for two heterozygotes. This finding indicated that the homozygous recessive ANS gene was primarily responsible for the pink color in this line. The two pink onions, heterozygous for the ANS gene, were also heterozygous for the DFR gene, which indicated that the pink color was produced by incomplete dominance of a red color gene over that of yellow. One pink line and six other segregating breeding lines were also analyzed. The genotyping results matched perfectly with phenotypic color segregation.