Genetic Analysis of Kernel Traits in Maize-Teosinte Introgression Populations.
Seed traits have been targeted by human selection during the domestication of crop species as a way to increase the 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 10-fold in the 9000 years since domestication from its wild ancestor, teosinte (Z. mays ssp. parviglumis). In order to study how size and shape affect kernel weight, we analyzed kernel morphometric traits in a set of 10 maize-teosinte introgression populations using digital imaging software. We identified quantitative trait loci (QTL) for kernel area and length with moderate allelic effects that colocalize with kernel weight QTL. 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 QTL with a range of allelic effects, enabling future research into the genetic basis of these traits.
Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211.
Zhengbin
Z
Liu
U.S. Department of Agriculture, Agricultural Research Service, Columbia, Missouri 65211.
Arturo
A
Garcia
Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211 U.S. Department of Agriculture, Agricultural Research Service, Columbia, Missouri 65211.
Michael D
MD
McMullen
Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211 U.S. Department of Agriculture, Agricultural Research Service, Columbia, Missouri 65211 Sherry.Flint-Garcia@ars.usda.gov.
Sherry A
SA
Flint-Garcia
D000483:Alleles; D002874:Chromosome Mapping; D007091:Image Processing, Computer-Assisted; D010641:Phenotype; D025341:Principal Component Analysis; D040641:Quantitative Trait Loci; D012639:Seeds / Q000235:genetics* / Q000502:physiology; D003313:Zea mays / Q000235:genetics* / Q000502:physiology
MPP; Multiparent Advanced Generation Inter-Cross (MAGIC); domestication; introgression population; kernel size and shape; kernel weight; multiparental populations; quantitative trait loci (QTL)