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

Abstract

BackgroundSorghum bicolor is the fifth most commonly grown cereal worldwide and is remarkable for its drought and abiotic stress tolerance. For these reasons and the large size of biomass varieties, it has been proposed as a bioenergy crop. However, little is known about the genes underlying sorghum’s abiotic stress tolerance and biomass yield.ResultsTo uncover the genetic basis of drought tolerance in sorghum at a genome-wide level, we undertook a high-density phenomics genome wide association study (GWAS) in which 648 diverse sorghum lines were phenotyped at two locations in California once per week by drone over the course of a growing season. Biomass, height, and leaf area were measured by drone for individual field plots, subjected to two drought treatments and a well-watered control. The resulting dataset of ~ 171,000 phenotypic data-points was analyzed along with 183,989 genotype by sequence markers to reveal 213 high-quality, replicated, and conserved GWAS associations.ConclusionsThe genomic intervals defined by the associations include many strong candidate genes, including those encoding heat shock proteins, antifreeze proteins, and other domains recognized as important to plant stress responses. The markers identified by our study can be used for marker assisted selection for drought tolerance and biomass. In addition, our results are a significant step toward identifying specific sorghum genes controlling drought tolerance and biomass yield.Electronic supplementary materialThe online version of this article (10.1186/s12864-018-5055-5) contains supplementary material, which is available to authorized users.

Evaluation of genetic diversity, agronomic traits, and anthracnose resistance in the NPGS Sudan Sorghum Core collection

“…Multiple association panels have been established to capture the genetic diversity present in the NPGS sorghum collection [8,[14][15][16]. These germplasm resources have been utilized to study grains and bioenergy related traits through the genome-wide association study (GWAS) [15,[17][18][19][20][21]. Nevertheless, these panels comprise converted sorghum lines (i.e., lines adapted to temperate regions) that represent most of the genetic diversity in breeding programs.…”

Genomics-assisted breeding in minor and pseudo-cereals

“…In GWAS of plant species, however, collecting and evaluating such a large number of genotypes may be impossible. Recently developed highthroughput phenotyping systems will help us collect phenotype data from large sample populations (e.g., Spindel et al 2018). For example, it is reported that image analysis can be used for phenotyping in GWAS of sorghum (Zhou et al 2019).…”

“…Furthermore, because highthroughput phenotyping technologies, such as drone remote sensing, are generally versatile and applicable to a wide variety of crop species, it should be easy to apply the technologies developed and used in major crops directly to minor and pseudo-cereals. New technologies for phenotyping enable us to perform QTL mapping/GWAS-based breeding, or GS for characteristics that have been difficult to evaluate so far (e.g., Sivasakthi et al 2018, Spindel et al 2018. High-throughput phenotyping will be indispensable in genomics-assisted breeding in the future.…”

Advanced Strategic Research to Promote the Use of Rice Genetic Resources

“…A single operator with a UAV and aerial image analysis software can cover the whole field site. In 10 min for UAV operation per hectare plus 1 h for image analysis, characterization of various agronomic traits such as leaf color, plant height, biomass, and flowering time can be obtained [42,43]. This new technology can significantly reduce labor and costs as compared with manual phenotyping methods requiring many genebank operators' time and effort.…”