Heterosis is prevalent for multiple traits in diverse maize germplasm.
BACKGROUND
Heterosis describes the superior phenotypes observed in hybrids relative to their inbred parents. Maize is a model system for studying heterosis due to the high levels of yield heterosis and commercial use of hybrids.


METHODS
The inbred lines from an association mapping panel were crossed to a common inbred line, B73, to generate nearly 300 hybrid genotypes. Heterosis was evaluated for seventeen phenotypic traits in multiple environments. The majority of hybrids exhibit better-parent heterosis in most of the hybrids measured. Correlations between the levels of heterosis for different traits were generally weak, suggesting that the genetic basis of heterosis is trait-dependent.


CONCLUSIONS
The ability to predict heterosis levels using inbred phenotype or genetic distance between the parents varied for the different traits. For some traits it is possible to explain a significant proportion of the heterosis variation using linear modeling while other traits are more difficult to predict.
Flint-Garcia
Sherry A
SA
USDA-ARS, Plant Genetics Research Unit, and Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America. sherry.flint-garcia@ars.usda.gov
Buckler
Edward S
ES
Tiffin
Peter
P
Ersoz
Elhan
E
Springer
Nathan M
NM
D003433:Crosses, Genetic; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D006823:Hybrid Vigor / Q000235:genetics*; D006824:Hybridization, Genetic; D016014:Linear Models; D015233:Models, Statistical; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D003313:Zea mays / Q000235:genetics* / Q000502:physiology*