Development of a MAGIC population and high-resolution quantitative trait mapping for nicotine content in tobacco

• Published in: Frontiers in plant science Vol. 13; p. 1086950
• Main Authors: 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
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 10.01.2023
• Subjects: GWAS; MAGIC population; nicotine content; Plant Science; QTL; tobacco; QTL; tobacco; GWAS; nicotine content; MAGIC population
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2022.1086950

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.