Data from: Increased power to dissect adaptive traits in global sorghum diversity using a nested association mapping population

Adaptation of domesticated species to diverse agroclimatic regions has led
to abundant trait diversity. However, the resulting population structure
and genetic heterogeneity confounds association mapping of adaptive
traits. To address this challenge in sorghum [Sorghum bicolor (L.)
Moench]—a widely adapted cereal crop—we developed a nested association
mapping (NAM) population using 10 diverse global lines crossed with an
elite reference line RTx430. We characterized the population of 2214
recombinant inbred lines at 90,000 SNPs using genotyping-by-sequencing.
The population captures ∼70% of known global SNP variation in sorghum, and
57,411 recombination events. Notably, recombination events were four- to
fivefold enriched in coding sequences and 5′ untranslated regions of
genes. To test the power of the NAM population for trait dissection, we
conducted joint linkage mapping for two major adaptive traits, flowering
time and plant height. We precisely mapped several known genes for these
two traits, and identified several additional QTL. Considering all SNPs
simultaneously, genetic variation accounted for 65% of flowering time
variance and 75% of plant height variance. Further, we directly compared
NAM to genome-wide association mapping (using panels of the same size) and
found that flowering time and plant height QTL were more consistently
identified with the NAM population. Finally, for simulated QTL under
strong selection in diversity panels, the power of QTL detection was up to
three times greater for NAM vs. association mapping with a diverse panel.
These findings validate the NAM resource for trait mapping in sorghum, and
demonstrate the value of NAM for dissection of adaptive traits.