September 26, 2019
Journal Article

Association mapping by aerial drone reveals 213 genetic associations for Sorghum bicolor biomass traits under drought

Julie Sievert
Joy Hollingsworth
John Vogel
Georg Jansson
Jennifer Spindel
Jeffrey Dahlberg
Matt Colgan
Scott Staggenborg
Bob Hutmacher
Sorghum (Sorghum bicolor) is the fifth most commonly grown cereal crop worldwide in large part due to its remarkable stress tolerance. It requires significantly less water to yield well than other major cereal crops and can survive harsher drought conditions. For these reasons as well as its size, it has also been recently proposed as a new bioenergy crop. However, despite the fact that sorghum is usually grown for its drought tolerant qualities, the genetic basis of its drought tolerance is still largely a mystery. To uncover the genetic basis of drought tolerance in sorghum at a comprehensive and genome-wide level, we undertook a high-density phenomics GWAS in which a diversity panel of ~640 sorghum lines were phenotyped in central California once per week by aerial drone over the course of a growing season. Plant biomass, height, and leaf area were measured by the drone for individual field plots, replicated over two drought treatments and a control treatment. The resulting dataset of over 171,000 phenotypic data-points was analyzed along with GBS data on the 640 sorghum lines to reveal more than 200 high-quality, replicated and conserved GWAS associations. We also introduce here new data analysis and visualization tools for highly dense phenotype datasets including a variation on the Manhattan plot we term the ‘Manhattan blot’. Our 200 associations include a number of very strong candidate genes, including those encoding heat shock proteins, antifreeze proteins, and other domains recognized as important to plant stress responses.

Revised: September 26, 2019 | Published: September 17, 2018

Spindel J., J.A. Dahlberg, M. Colgan, J. Hollingsworth, J. Sievert, S. Staggenborg, and B. Hutmacher, et al. 2018. "Association mapping by aerial drone reveals 213 genetic associations for Sorghum bicolor biomass traits under drought." BMC Genomics 19. PNNL-SA-131382. doi:10.1186/s12864-018-5055-5