Construction of maize-teosinte introgression line population and identification of major quantitative trait loci

Maize (Zea mays L.) is a staple food and energy crop worldwide. As the closest related wild progenitor of maize, teosinte (Z. mays ssp. Parviglumis) can, therefore, be a rich resource for useful variants lost during domestication. Here, we used the maize inbred line, B73, as the recurrent parent and a teosinte subspecies, K67-11, as the donor, and constructed a introgression line (IL) population. In brief, 10 K single nucleotide polymorphism (SNP) chips were used to genotype 135 maize-teosinte ILs from the BC2F4 population. Then, quantitative trait locus (QTL) mapping was performed for five plant-type and five ear traits across two different environments. In total, 94 putative QTLs were detected in a single environment analysis, whereas 14 QTLs were detected in two environments. In the whole genome, four regions controlling multiple traits were detected by comparing QTL distribution. Thus, these segments were possibly related to the functional regions controlling the aforementioned traits of maize. These results may not only be helpful for fine-mapping of major QTLs related to important agronomic traits in maize but also provide a valuable reference for molecular marker-assisted breeding and related basic research in maize.

Automated summary

This study constructed a maize-teosinte introgression line population using the maize inbred line B73 and teosinte subspecies K67-11, and performed genotype analysis and QTL mapping to reveal the genetic loci controlling traits. The results identified valuable regions in the genome associated with important agronomic traits in maize, providing insights for fine-mapping and marker-assisted breeding in maize.