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Genetic analysis of kernel traits in maize-teosinte introgression populations
- Zhengbin Liu, Arturo Garcia, Michael D. McMullen, Sherry A. Flint-Garcia
- G3-GenesGenomesGenetics 2016 v.6 no.8 pp. 2523-2530
- Zea mays subsp. mays, Zea mays subsp. parviglumis, computer software, corn, crops, domestication, farming systems, genetic techniques and protocols, grain yield, humans, image analysis, introgression, loci, morphometry, nutrient content, quantitative trait loci, seeds
- Seed traits have been targeted by human selection during the domestication of crop species as a way to increase caloric and nutritional content of food during the transition from hunter-gather to early farming societies. The primary seed trait under selection was likely seed size/weight as it is most directly related to overall grain yield. Additional seed traits involved in seed shape may have also contributed to larger grain. Maize (Zea mays ssp. mays) kernel weight has increased more than ten-fold in the 9000 years since domestication from its wild ancestor, teosinte (Zea mays ssp. parviglumis). In order to study how size and shape affect kernel weight, we analyzed kernel morphometric traits in a set of ten maize-teosinte introgression populations using digital imaging software. We identified QTLs for kernel area and length with moderate allelic effects that co-localize with kernel weight QTLs. Several genomic regions with strong effects during maize domestication were detected and a genetic framework for kernel traits was characterized by complex pleiotropic interactions. Our results both confirm prior reports of kernel domestication loci and identify previously uncharacterized QTLs with a range of allelic effects enabling future research into the genetic basis of these traits.