Chinese cabbage is one of most important vegetable crop in Eastern Asian countries including Korea. Because Chinese cabbage is a leafy vegetable, genetic research with respect to the leaf morphology is important. In this research, we have used two inbred lines of Chinese cabbages (Kenshin and RCBr) and generated recombinant lines having various leaf morphology. In F2 population of Kenshin X RCBr, leaf shape showed very dramatic variations with normal distribution in terms of leaf size, petiole length, leaf margin and etc. Microarray with a 135K DNA chip (version 3) integrated 2 sets of total Chinese cabbage genes. Biological process of candidate genes was classified into transcription factor, genes encoding kinase activity protein, protein folding related genes, oxidation-reduction process genes. Putative leaf-morphology-related genes were 142 that are involed in phytohormone pathway genes, cell proliferation & cell elongation related genes and genes controlling leaf morphogenesis etc. These genes are further classified to phytohormone signaling-associated genes (SAUR44, PIN2, CPK6, RDUF2), leaf development regulating genes (DWF4, CUC2, TCP15, BLH4, NGA4), and cell division and cell growth related genes (ILP1, TCTP, EMB1027).

To select genes associated with the high-temperature tolerance from Brassica, two transcriptomic analyses have been used: microarray and RNA Seq. Using two contrasting inbred lines of B. rapa, Chiifu and Kenshin, version 3 microarray (135 K microarray) was conducted to RNA samples extracted from series of 45℃-treated leaves and 29 genes were selected for genomic DNA cloning of cabbage. Of 29 genes, 8 genes contain 40 SNPs, 11 SSRs and 23 In-Del markers that distinguish high-temperature tolerant and susceptible cabbages, BN1 and BN2. These 8 genes include a unknown gene, AP2, SMP, FBD, SKP2B, IAA16, HSP21 and OLI2-2. We also selected 16 cabbage genes from RNA Seq analysis using two inbred lines, BN1 and BN2: 5 genes for BN1-high expression, 5 genes for BN1-specific expression, 5 genes for BN2-specific expression, and BoCaMB. Using RNA sequences, genomic DNAs corresponding to 16 genes have been clones and analyzed to find out molecular markers. Markers were further transformed into PCR-based marker and confirmed with additional cabbage genetic lines. We are currently transforming PCR-makers into SNP markers. To examine function of high-temperature tolerant genes, we also transformed 5 genes into Arabidopsis plants. We will describe detailed methods and results in a poster. [This work was supported by a grant from the Next-Generation BioGreen 21 Program (the Next-Generation Genomics Center No. PJ009085), Rural Development Administration, Republic of Korea]