• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.772-784
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• 2012

Marker-assisted gene pyramiding aims to produce individuals with superior economic traits according to the optimal breeding scheme which involves selecting a series of favorite target alleles after cross of base populations and pyramiding them into a single genotype. Inspired by the science of evolutionary computation, we used the metaphor of hill-climbing to model the dynamic behavior of gene pyramiding. In consideration of the traditional cross program of animals along with the features of animal segregating populations, four types of cross programs and two types of selection strategies for gene pyramiding are performed from a practical perspective. Two population cross for pyramiding two genes (denoted II), three population cascading cross for pyramiding three genes(denoted III), four population symmetry (denoted IIII-S) and cascading cross for pyramiding four genes (denoted IIII-C), and various schemes (denoted cross program-A-E) are designed for each cross program given different levels of initial favorite allele frequencies, base population sizes and trait heritabilities. The process of gene pyramiding breeding for various schemes are simulated and compared based on the population hamming distance, average superior genotype frequencies and average phenotypic values. By simulation, the results show that the larger base population size and the higher the initial favorite allele frequency the higher the efficiency of gene pyramiding. Parents cross order is shown to be the most important factor in a cascading cross, but has no significant influence on the symmetric cross. The results also show that genotypic selection strategy is superior to phenotypic selection in accelerating gene pyramiding. Moreover, the method and corresponding software was used to compare different cross schemes and selection strategies.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.101-106
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• 2008

To identify inheritance of clubroot disease resistance genes in Chinese cabbage, seedling tests of $BC_1P_1,\;BC_1P_2$, and $F_2$ populations derived from $F_1$ hybrid(var. CR Saerona) using single spore isolate(race 4 identified with William's differential host) from Plasmodiophora brassciae were conducted. Resistance(R) and susceptible(S) plants segregated to 1:0 in backcross to the resistant parent. The $F_2$ population segregated in a 3(R):1(S) ratio. This result implied that the resistance of clubroot disease is controlled by a single dominant gene to the race 4 of P. brassicae in CR Saerona. To develop DNA markers linked to clubroot resistance genes, 185 plants of CR Saerona among $F_2$ populations were used. A total of 300 arbitrary decamer was applied to $F_2$ population using BSARAPD(Bulked segregant analysis-Randomly amplified polymorphic DNA). One RAPD marker linked to clubroot resistance gene in CR Saerona($OPJ_{1100}$) was identified. This marker was 3.1 cM in distance from resistance gene in $F_2$ population. This marker may be useful for a marker-assisted selection(MAS) and gene pyramiding of the clubroot disease resistant gene in Chinese cabbage breeding programs.

• 한국육종학회지
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• 제50권4호
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• pp.387-395
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• 2018

다산 등 15개의 통일형 벼 품종을 이용하여 mesotrione을 처리한 후 5일부터 다산 등 13개 품종들은 신엽에서 백화현상이 발생하였으나, 밀양154호와 수원382호는 백화현상이 발생하지 않아 저항성 품종으로 선발되었다. Mesotrione 처리 후 다산 등 13개 품종들의 초장 및 건물중 억제율은 밀양154호와 수원382호보다 더 높았으며 약량에 따른 억제율이 증가하였다. 한아름2호/밀양154호의 $F_2$ 집단을 이용한 유전분석 결과 저항성이 149개체, 감수성이 41개체로 이론적 분리비 3:1($X^2=1.19$, P=0.31)에 적합하여, mesotrione 저항성 관련 유전자는 1개의 우성유전자에 지배되는 것으로 나타났다. BSA방법을 이용하여 mesotrione 저항성 관련 유전자를 탐색한 결과, 2번 염색체의 10.2 Mb에 위치한 SSR marker RM1358과 RM3501을 선발하였다. Fine mapping을 위해 선발된 5개의 저항성 개체 중에서 $F_2-137$은 RM12921부터 RM3501까지 재조환이 일어났고, $F_2-76$은 RM324부터 RM5101까지 재조환이 일어났다. 따라서, mesotrione 저항성 관련 유전자는 RM3501과 RM324 사이인 10.2 Mb~11.4 Mb에 존재하며, RM3501과 RM324의 조환률이 각각 0.53%과 2.65%이므로, RM3501을 mesotrione저항성 유전자 DNA 연관 marker로 선발하였다. 다산 등 20개 통일형 품종 및 mesotrione에 저항성을 나타내는 자포니카 품종인 운광과 감수성인 통일형 한아름의 $BC_2F_2$ 집단을 이용하여 RM3501의 MAS 이용 가능성을 검토한 결과, mesotrione 저항성 선발 marker로 활용은 가능하나, 정확한 선발 maker로 활용하기 위해서는 추가적인 실험이 필요할 것으로 판단된다.

• Journal of Crop Science and Biotechnology
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• 제10권4호
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• pp.201-210
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• 2007

Soybean [Glycine max(L.) Merr.] oil is versatile and used in many products. Modifying the fatty acid profile would make soy oil more functional in food and other products. The ideal oil with the most end uses would have saturates(palmitic + stearic acids) reduced from 15 to < 7%, oleic acid increased from 23 to > 55%, and linolenic acid reduced from 8 to < 3%. Reduced palmitic acid(16:0) is conditioned by three or more recessive alleles at the Fap locus. QTLs for reduced palmitic acid have mapped to linkage groups(LGs) A1, A2, B2, H, J, and L. Genes at the Fad locus control oleic acid content(18:1). Six QTLs($R^2$=4-25%) for increased 18:1 in N00-3350(50 to 60% 18:1) explained four to 25% of the phenotypic variation. M23, a Japanese mutant line with 40 to 50% 18:1 is controlled by a single recessive gene, ol. A candidate gene for FAD2-1A can be used in marker-assisted breeding for high 18:1 from M23. Low linolenic acid(18:3) is desirable in soy oil to reduce hydrogenation and trans-fat accumulation. Three independent recessive genes affecting omega-3 fatty acid desaturase enzyme activity are responsible for the lower 18:3 content in soybeans. Linolenic acid can be reduced from 8 to about 4, 2, and 1% from copies of one, two, or three genes, respectively. Using a candidate gene approach perfect markers for three microsomal omega-3 desaturase genes have been characterized and can readily be used in for marker assisted selection in breeding for low 18:3.

• Journal of Korean Neurosurgical Society
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• 제53권4호
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• pp.241-244
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• 2013

The authors describe the use of a self-expandable stent in a temporary deployment for treatment of a very wide-neck A1 segment of anterior cerebral artery (ACA) aneurysm following incomplete clipping. A 39-year-old hypertensive man presenting with seizure-like movement underwent computed tomography, which showed acute subarachnoid hemorrhage and an A1 segment of ACA aneurysm with superior and inferior projection. He underwent surgical clipping of the aneurysm, but superior and posterior portion of wide-neck aneurysm remained. We decided to treat the remnant aneurysm using an endovascular modality. After selection of the aneurysm, coil packing was performed assisted by the temporary semi-jailing technique. The Enterprise stent (Cordis Neurovascular, Miami, FL, USA) was deployed and recaptured repeatedly for angiography to ensure safety of the small caliber parent artery. Successful semi-deployment and recapture of the stent allowed subtotal coil occlusion of the aneurysm with good anatomic and clinical results. No complications were encountered. The stent could be recaptured up to the point where the proximal end of the stent marker was aligned with distal marker band of the microcatheter, approximately 70% of the stent length. The temporary semi-jailing technique is feasible for wide-neck aneurysm with small caliber parent artery.

• 한국육종학회지
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• 제40권3호
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• pp.215-222
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• 2008

Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.

• 한국작물학회지
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• 제48권6호
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• pp.419-423
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• 2003

우리나라 자포니카 품종의 흰잎마름병 저항성 유전자와 연관된 마커를 탐색하기 위하여, 밀양121호, 밀양123호 및 HB10624-AC5 등을 교배친으로 한 두 조합의 약배양 계통을 재료로 흰잎마름병 저항성 유전자(Xa-1 and Xa-3)와 DNA 마커간의 연관분석을 통하여 유전자 지도를 작성하고자 수행하였던 결과를 요약하면 다음과 같다. 1. $\textrm{K}_1$ 균주에 대한 흰잎마름병 저항성 검정결과, 밀양121호/HRl1650-1-4-2에서는 저항성과 감수성이 1:1로 분리하였으며, 밀양123호/HR10624-AC5 조합의 $\textrm{K}_1$ 및 $\textrm{K}_3$ 균주에 대한 검정결과는 각각 3:1과 1:1로 분리하여 이론치에 합당하였다. 2. 교배친에 대하여 DraI. HindIII, EcoRI, EcoRV, PstI등 5가지 제한효소에 대한 다형현상을 검정한 결과, RZ590, RG303, RZ536 등 3개의 마커가 다형현상을 나타내었다. 3. 흰잎마름병 포장저항성 검정결과와 RFLP 마커와의 연관분석 결과 Xa-1 유전자는 RZ590과 4번 염색체 상에서 3.1$\times$1.5 cM으로 연관되어 있었으며, Xa-3 유전자는 Rz536 및 RG303과 11번 염색체 상에서 각각 7.6$\times$2.3 및 16.0$\times$3.2 cM으로 연관되어 있었다. 4. 11번 염색체 상에서 Xa-3와 Rz536 및 RG303은 "Xa-3-RZ536-RG303" 순으로 위치하였다.순으로 위치하였다.

• 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.

• 생명과학회지
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• 제21권12호
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• pp.1659-1665
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• 2011

감귤류 중 수술이 퇴화되어 웅성불임형질을 나타내는 '청견' 품종에 정상적인 수술의 형태를 가진 웅성가임인 '진귤' 품종을 교배하여 150개체의 $F_1$ 집단을 구축하여 수술이 퇴화되는 개체와 정상인 개체를 분리하였다. 분리된 F1 개체들을 사용하여 SRAP 기법과 집단 분리 분석법(BSA)을 조합하여 웅성 가임 연관 마커 개발에 활용하였다. $F_1$ 집단 내 150개체 중 66개체가 퇴화 수술을 갖고 있으며 웅성 가임성과 웅성 불임성의 분리비는 1:1이며 $x^2$ 값은 2.16(p=0.05)이었다. 197개의 SRAP 프라이머 조합들 중 웅성가임 특이밴드를 형성하는 3개의 SRAP 프라이머 조합(F4/R27, F39/R60, 및 F15/R37)을 선발하였으며, 이 중 F39/R60 프라이머에 특이적으로 증폭하는 DNA단편의 염기서열을 기본으로 하여 새롭게 작성한 양방향 프라이머 조합 중 웅성 가임 계통에서만 약 1.4 Kb의 특이밴드를 증폭하는 프라이머 조합, pMS 33U/pMS 1462L를 선발하여 SCAR 마커를 개발 하였다. 이러한 결과는 개발된 SCAR 마커로 무핵성 계통들의 육종 선발에 효율성을 높일 수 있을 것으로 기대된다.

• 원예과학기술지
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• 제35권3호
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• pp.333-343
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• 2017

Bloomless cucumber fruits are commercially produced by grafting onto the pumpkin stocks (Cucurbita moschata) to restricted silicon ($SiO_2$) absorption. Inhibition of silicon absorption in bloomless stocks is conferred by a mutant allele of the CmLsi1 homologous to Lsi1 in rice. In this study, we characterized the Lsi1 homologs in pumpkin (C. moschata) and its cold-tolerant wild relative C. ficifolia ('Heukjong') in order to develop a DNA marker for selecting a bloomless trait and to establish the molecular basis for breeding bloomless stock cultivars of C. ficifolia. A Cleaved amplified polymorphic sequence (CAPS) marker (CM1-CAPS) was designed based on a non-sysnonymous single nucleotide polymorphism (SNP, C>T) of the CmLsi1 mutant-type allele, and its applicability for Marker-assisted selection (MAS) was confirmed by evaluating three bloom and five bloomless pumpkin stock cultivars. Quantitative RT-PCR of the CmLsi1 for these stock cultivers implied that expression level of the CmLsi1 gene does not appear to be associated with the bloom/bloomless trait and may differ depending on plant species and tissues. A full length cDNA of the Lsi1 homolog [named CfLsi1($B^+$)] of 'Heukjong' (C. ficifolia), was cloned and sequence comparison between CmLsi1($B^+$) and CfLsi1($B^+$) revealed that there exists total 24 SNPs, of which three were non-synonymous. Phylogenetic analysis of CfLsi1($B^+$) and Lsi1 homologs further revealed that CfLsi1($B^+$) is closesly related to Nodulin 26-like intrinsic proteins (NIPs) and most similar to CpNIP1 of C. pepo than C. moschata.