It is necessary to carry out a risk assessment to determine the consequences of releasing a particular plant species containing specific transgenes before transgenic plants can be grown under filed conditions. Gene flow from transgenic plants to wild closely related species has raised concern recently. Since transgenic crops were released in 1996, the global area of transgenic crops has been increasing rapidly. The transgene introgression from transgenic crops to their wild relatives is unavoidable in some species. Transgene introgression is of concern because the crop–wild plant hybrids might be conferred with a selection advantage to increase their performance, which could result in negative ecological consequences to natural ecosystems. The genus Brassica has 159 species, including a number of wild species that are of great importance to the economy. Most transgenic Brassica gene flow research has focused on the most successful cross between transgenic oilseed rape Brassica napus and its wild relatives Brassica rapa, a widely distributed weed in the farming system in Europe and America, since the hybridization can spontaneously happen and the generations can backcross to B. rapa easily in the wild conditions. In this study, we aimed to characterize transgene introgression, segregation, and expression in backcrossed generations between tramsgenic B. napus and B. rapa. These results will contribute to the environmental risk assessment and assist in biosafety management.

본 연구는 유채-MS를 이용하여 배추와 순무 등을 화분친으 로 활용 잎의 모용이 없는 유채 잎에 배추와 순무의 엽색과 엽형 을 도입하여 소비자가 선호하는 새로운 형질을 갖춘 엽채소의 작출 가능성을 검토하고자 실시하였다. 교배효율에 영향을 미 치는 인공수분 후 주두 위에서의 화분발아나 화분관 신장은 유 채-MS와 배추간 종간 교배 조합에서 유채-MS와 순무간 종간 교잡보다 빠르게 진행되었으며, 유채-MS와 배추간 종간교잡 에서의 결협율이 90.6%로 유채-MS와 순무의 교배 결협율 67.3% 보다 23.3% 정도 높게 나타났으며, 협당결실립수는 각각 15.5립, 11.6립으로 나타나 유채-MS와 배추간의 종간교잡 효 율이 높았다. 유채-MS와 배추의 종간교잡 F1 잡종의 표현형질 의 특성은 주로 모계인 유채와 비슷하였으며 엽색은 밝은 녹색 으로 양친의 중간형을 나타냈고 모용은 적게 분포되어 있었으 며 엽수는 10.2매, 엽장은 27.5 ㎝, 엽폭은 14.0 ㎝로 잎의 길이 와 넓이가 유채에 비하여 커졌다. 유채-MS와 순무의 종간교잡 F1 잡종의 엽수는 9.6매, 엽장은 21.6 ㎝, 엽폭은 10.6 ㎝로 잎의 크기, 형태 및 결각 등은 양친의 중간형을 나타냈으며 엽색은 모 본인 유채와 비슷하거나 좀 더 짙은 녹색이었고, 모용이 잎의 앞 과 뒷면에 존재하였다.

Recent studies revealed that about 240 species in the tribe Brassiceae are derived through diploidization process from an ancient hexaploid after divergence with Arabidopsis. Most triplicates in Brassica genome show sequence-level co-linearity with a counterpart Arabidopsis sequence. We have obtained 91,511 BAC end sequences (BES) and high-resolution fingerprints (SNapShot) from 99,456 BAC clones originated three BAC libraries (HindIII, BamHI, and Sau3AI). All BESs were used for comparative genome analysis with the Arabidopsis. A total of 47,748 (52%) BESs show significant hit (E-6) with at least one spot of Arabidopsis chromosomes. And a total of 4,647 BAC clones (10%) are mapped on the counterpart Arabidopsis chromosomes by directional matches of both ends (9,294 BES) within 30-500 kb interval on Arabidopsis chromosome. These 4,647 clones span 92 Mb of Arabidopsis genome. We have selected a total of 629 BACs that span 86 Mb Arabidopsis genome with minimally comparative overlap (comparative-tile). Up to now, about 600 BACs are sequenced and most show co-linearity with the counterparts. Sequence-based genetic mapping of each BAC and their FPC information will be used as step-stone for walking and construction physical map of all chromosomes. Up to now, 513 BACs are sequence-based anchored on ten B. rapa genetic linkage groups that provide successful information as seed BACs for further extending to close clone gaps between the adjacent seed BACs and thus to complete sequencing of the individual chromosome. We are sequencing cytological chromosome 1 (R9) and 2 (R3), until now we finished about 50% of each chromosome. We also analyzed 130,000 ESTs from 29 cDNA libraries made with various tissues at various developing stage and treatments. The hybridization results of 24K microarray will be presented. All information will be provided to Multinational Brassica Genome Project (MBGP) members, soon, using web-based tool from our Arabidopsis-Brassica Genome Browser (www.brassica-rapa.org).