Glucosinolates of Brassica rapa collection from Korea genebank were measured to determine total glucosinolate content and their variation of diverse glucosinolates; Around 100 accessions representing the different morphotypes and geographical origin of Brassica rapa were analysed. The principal component analysis was performed to evaluate the differences among morphotypes using the profiles of 14 glucosinolates identified from the leaves. DMRT test and box plots showed the significant difference between total glucosinolates of subspecies. Most of turnip accessions had higher gluconilates compared to the other type accessions, Chinese cabbage and pak choi. These accessions will be used for GWAS study for glucosinolate. Now they are being finger-printed by genotyping by sequencing (GBS). Among these accession, we selected a turnip accession with high amount of glucosinolate, K0466 and two Chinese cabbage accession with low amount of glucosinolate, K0015 and K0621. To analyse quantitative traits loci (QTL) for glucosinolate synthesis, these three accessions were fixed through microspore culture. Finally, six homozygous lines were selected and were crossed each other to make F1 hybrids. We just harvested F2 seeds and transferred doubled haploid plants to pots. QTL analysis for glucosinolate will be performed these F2 and DH population.

We have identified ATTIRTA1 transposon, a kind of mariner-type DNA transposon from Brassica rapa genome. A total of 811 inverted-terminal repeat, ITR consisting of the both terminal on ATTIRTA1 transposon were found from B. rapa v1.1 sequence. Among them 616 ITR were paired by two in each transposon, indicating three quarters of the transposon exists in original form. Around 10 percentage of the transposon, 82 ITR was located in gene, expecially only in intron. Using these ATTRRTA1, we developed a display system modified from AFLP technique and applied for this system to analyze genetic diversity of Korea Brassica rapa core collection. The collection includes 220 accessions representing the different morphotypes and geographical origin. The analysis of population structure revealed five subgroups and the clustering patterns matched well with their morphological traits. ATTIRTA1 transposon display seems useful marker system for studying genetic relationships. Presently we have profiled the components and contents of glucosinolate in the core collection to analyze genome wide association. This collection will be helpful to identify agriculturally desirable traits from other supspecies.