Although much effort has been made to find agronomically important loci in the soybean plant, extensive linkage disequilibrium and genome duplication have limited efficient genome-wide linkage analyses that can identify important regulatory genes. In this respect, recombination block-based analysis of cultivated plant genomes is a potential critical step for molecular breeding and target locus screening. We propose a new three-step method of detecting recombination blocks and comparative genomics of bred cultivars. It utilizes typical reshuffling features of their genomes, which have been generated by the recombination processes of breeding ancestral genomes. To begin with, mutations were detected by comparing genomes to a reference genome. Next, sequence blocks were examined for likenesses and difference with respect to the reference genome. The boundaries between the blocks were taken as recombination sites. All recombination sites found in the cultivar set were used to split the genomes, and the resulting sequence fragments were named as core recombination blocks (CRBs). Finally, the genomes were compared at the CRB level, instead of at the sequence level. In the genomes of the five Korean soybean cultivars used, the CRB-based comparative genomics method produced long and distinct CRBs that are as large as 22.9 Mb. We also demonstrated efficiency in detecting functionally useful target loci by using indel markers, each of which represents a CRB. We further showed that the CRB method is generally applicable to both monocot and dicot crops, by analyzing publicly available genomes of 31 soybeans and 23 rice accessions.

Resequencing data is actively used for searching QTL or analyzing genetic diversity in the crops. However, the complexity of genome, caused by genome duplication, limits the utility of genome-wide association studies and linkage analyses to identify genes that regulate agronomically valuable traits. Here, we propose a comparative genomics approach based on core or common variation-based recombination blocks (CRB) using single nucleotide variation (SNV) density information. We found that the soybean genomes are assembled with long and distinct CRBs as large as 10Mb. CRB-based comparative genomics enabled us to accurately identify recombination blocks at the whole-chromosome level. We identified the Ih locus that determines the yellow hilum color in soybeans using CRB-based mapping with representative indel markers. These results suggest that the CRB-based comparison method is a promising platform for molecular breeding and map-based cloning.

본 연구에서는 RNAi 기작을 이용하여 식미에 중요한 영향을 미치는 아밀로스 함량을 다양화하기 위해 GBSSI 유전자의 3’-UTR 부위를 targeting하여 dsRNA를 생성시킬 수 있는 운반체를 제작하고, 벼에 형질전환 하였다. 작성된 형질전환체들을 대상으로 I2-KI 용액 반응과 아밀로스 함량을 분석한 결과, I2-KI 용액에 대한 반응은 waxy 타입으로 나타났으나 아밀로스 함량은 찰벼와 저아밀로스 벼 사이에 해당되는 범위를 보였다. 원품종과

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

본 연구는 최근 우리나라에서 급격하게 발생되고 있는 콩 불마름병에 대한 저항성 중간모본을 육성하고자 할 때 marker-assisted selection에 적용할 수 있는 저항성 근접 분자표지를 개발하고자 수행하였다. 1. 불마름병에 이병성인 큰올콩과 저항성인 신팔달콩의 RIL 116 계통에 대하여 콩 불마름병 균주 8ra에 대한 저항성과 연관된 QTL을 탐색한 결과 포장에서는 연관군 B2, D2, I와 K에서, 온실에서는 연관군 D2, C1과 F에서

1. 본 연구에서는 완두유래의 세포질성 PsAPX1 유전자를 대상으로 산화스트레스 유도성 프로모터를 연결하여 엽록체에 targeting 되는 과발현 운반체를 제작하고 벼에 도입한 결과 형질전환체에서 도입유전자 수가 1~3 copy인 것으로 나타나, 적은 수의 유전자가 안정적으로 도입되었음을 확인하였다. 2. 염, 오존, 자외선, 한발과 같은 다양한 환경스트레스 조건에서 내성이 증진된 우수 계통을 선발하기 위하여 작성된 형질전환 벼 계통들을 대상으로 생물

1. 본 연구에서는 공동배양 배지에 Agrobacterium 성장 억제물질인 silver nitrate를 첨가하고 변온과 여과지처리를 추가하여 공동배양 기간을 7일로 늘였으며, 또한 항산화 물질 3종을 공동배양 배지에 첨가하여 세포의 oxidative burst를 최소화함으로써 벼 형질전환효율을 높일 수 있었다. 또한 이 방법을 적용하여 형질전환이 어려운 품종을 대상으로도 형질전환 식물체를 작성할 수 있었다. 2. 벼 형질전환체의 70%에서 도입유전자

Agronomic characteristics of transgenic herbicide-resistant rice lines were evaluated under field condition. Differences in agronomic traits and rice quality were observed between transgenic plants and the corresponding untransformed controls. Transgenic Ilpumbyeo lines flowered earlier than untransformed controls, whereas transgenic Nagdongbyeo flowered at the same time as untransformed control. With regard to the yield and rice quality, most of the transgenic lines showed lower yield than control except some selected transgenic lines. Selected Nagdongbyeo transgenic line also showed good eating quality comparable to the control although most selected Ilpumbyeo transgenic lines showed slightly lower eating quality and increased white center/belly in the rice grain. In order to find the main factor leading to somaclonal variation among transgenic lines, Tos17, a rice retrotransposon activated by prolonged tissue culture period was investigated. Although the transgenic lines carried only one or two of transformed bar gene, the copy number of Tos17 increased in most transgenic lines compared with control. The activation of Tos17 was not detected in selected promising transgenic lines such as ND115-15-1-B and IP23-3-3, suggesting that the increased copy number of Tos17 may have negatively affected agronomic characteristics of transgenic rice.