Characterization of introgression from the teosinte Zea mays ssp. mexicana to Mexican highland maize
Eric Gonzalez-Segovia,
Sergio Pérez-Limon,
G. Carolina Cíntora-Martínez,
Alejandro Guerrero-Zavala,
Garrett M. Janzen,
Matthew B. Hufford,
Jeffrey Ross-Ibarra,
Ruairidh J. H. Sawers
Affiliations
Eric Gonzalez-Segovia
Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, Mexico
Sergio Pérez-Limon
Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, Mexico
G. Carolina Cíntora-Martínez
Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, Mexico
Alejandro Guerrero-Zavala
Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, Mexico
Garrett M. Janzen
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
Matthew B. Hufford
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
Jeffrey Ross-Ibarra
Department of Plant Sciences, Center for Population Biology, and Genome Center, University of California,, Davis, CA, USA
Ruairidh J. H. Sawers
Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, Mexico
Background The spread of maize cultivation to the highlands of central Mexico was accompanied by substantial introgression from the endemic wild teosinte Zea mays ssp. mexicana, prompting the hypothesis that the transfer of beneficial variation facilitated local adaptation. Methods We used whole-genome sequence data to map regions of Zea mays ssp. mexicana introgression in three Mexican highland maize individuals. We generated a genetic linkage map and performed Quantitative Trait Locus mapping in an F2 population derived from a cross between lowland and highland maize individuals. Results Introgression regions ranged in size from several hundred base pairs to Megabase-scale events. Gene density within introgression regions was comparable to the genome as a whole, and over 1,000 annotated genes were located within introgression events. Quantitative Trait Locus mapping identified a small number of loci linked to traits characteristic of Mexican highland maize. Discussion Although there was no strong evidence to associate quantitative trait loci with regions of introgression, we nonetheless identified many Mexican highland alleles of introgressed origin that carry potentially functional sequence variants. The impact of introgression on stress tolerance and yield in the highland environment remains to be fully characterized.
