AUTHOR=Yuan Guangdi , Sun Kefan , Yu Wenlong , Jiang Zipeng , Jiang Caihong , Liu Dan , Wen Liuying , Si Huan , Wu Fengyan , Meng He , Cheng Lirui , Yang Aiguo , Wang Yuanying TITLE=Development of a MAGIC population and high-resolution quantitative trait mapping for nicotine content in tobacco JOURNAL=Frontiers in Plant Science VOLUME=13 YEAR=2023 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1086950 DOI=10.3389/fpls.2022.1086950 ISSN=1664-462X ABSTRACT=

Multiparent Advanced Generation Inter-Cross (MAGIC) population is an ideal genetic and breeding material for quantitative trait locus (QTL) mapping and molecular breeding. In this study, a MAGIC population derived from eight tobacco parents was developed. Eight parents and 560 homozygous lines were genotyped by a 430K single-nucleotide polymorphism (SNP) chip assay and phenotyped for nicotine content under different conditions. Four QTLs associated with nicotine content were detected by genome-wide association mapping (GWAS), and one major QTL, named qNIC7-1, was mapped repeatedly under different conditions. Furthermore, by combining forward mapping, bioinformatics analysis and gene editing, we identified an ethylene response factor (ERF) transcription factor as a candidate gene underlying the major QTL qNIC7-1 for nicotine content in tobacco. A presence/absence variation (PAV) at qNIC7-1 confers changes in nicotine content. Overall, the large size of this MAGIC population, diverse genetic composition, balanced parental contributions and high levels of recombination all contribute to its value as a genetic and breeding resource. The application of the tobacco MAGIC population for QTL mapping and detecting rare allelic variation was demonstrated using nicotine content as a proof of principle.