Su Ryun Choi1, Xiaona Yu1, Vignesh Dhandapani1, Xiaonan Li2, Zhi Wang3, Seo Yeon Lee 1, Sang Heon Oh1, Wenxing Pang2, Nirala Ramchiary4, Chang Pyo Hong5, Suhyoung Park6, Zhongyun Piao2, HyeRan Kim7, Yong Pyo Lim1,*
1 Department of Horticulture, Chungnam National University, Daejeon, Korea
2 Department of Horticulture, Shenyang Agricultural University, Shenyang, China
3 Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China
4 School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
5 Theragen Bio Institute, TheragenEtex, Suwon, Korea
6 Vegetable Research Division, National Institute of Horticultural and Herbal Science, Wanju-gun, Korea
7 Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
Su Ryun Choi and Xiaona Yu contributed equally to this work.
Brassica rapa is an important leafy vegetable consumed worldwide and morphology is a key character for its breeding. To enhance genetic control, quantitative trait loci (QTLs) for leaf color and plant architecture were identified using two immortalized populations with replications of 2 and 4 years. Overall, 158 and 80 QTLs associated with 23 and 14 traits were detected in the DH and RIL populations, respectively. Among them, 23 common robust-QTLs belonging to 12 traits were detected in common loci over the replications. Through comparative analysis, five crucifer genetic blocks corresponding to morphology trait (R, J&U, F and E) and color trait (F, E) were identified in three major linkage groups (A2, A3 and A7). These might be key conserved genomic regions involved with the respective traits. Through synteny analysis with Arabidopsis, 64 candidate genes involved in chlorophyll biosynthesis, cell proliferation and elongation were co-localized within QTL intervals. Among them, SCO3, ABI3, FLU, HCF153, HEMB1, CAB3 were mapped within QTLs for leaf color; and CYCD3;1, CYCB2;4, AN3, ULT1 and ANT were co-localized in QTL regions for leaf size. These robust QTLs and their candidate genes provide useful information for further research into leaf architecture with crop breeding.