Abstract Detail

Crops and Wild Relatives

Gao, Lexuan [1], Lee, Joon Seon [2], Hübner, Sariel [1], Hulke, Brent [3], Qu, Yan [1], Rieseberg, Loren [4].

Genetic and phenotypic analyses indicate that resistance to flooding stress is uncoupled from performance in cultivated sunflower.

Given the rising risk of extreme weather caused by climate change, enhancement of abiotic stress-resistance in crops is increasingly urgent. But will the development of stress-resistant cultivars come at the cost of yield under ideal conditions? We hypothesize that this need not be inevitable, because resistance alleles with minimal pleiotropic costs may evade artificial selection and be retained in crop germplasm. Genome-wide association (GWA) analyses for variation in plant performance and flooding response were conducted in cultivated sunflower, a globally important oilseed.We observed broad variation in flooding responses among genotypes. Flooding resistance was not strongly correlated with performance in control conditions, suggesting no inherent trade-offs. Consistent with this finding, we identified a subset of loci conferring flooding resistance, but lacking antagonistic effects on growth. Genetic diversity loss at candidate genes underlying these loci was significantly less than for other resistance genes during cultivated sunflower evolution. Despite bottlenecks associated with domestication and improvement, low cost resistance alleles remain within the cultivated sunflower gene pool. Thus, development of cultivars that are both flooding tolerant and highly productive should be straightforward. Results further indicate that estimates of pleiotropic costs from GWA analyses explain, in part, patterns of diversity loss in crop genomes.

1 - University of British Columbia, Botany, 6270 University BLVD, Rieseberg lab, Vancouver, BC, V6T1Z4, Canada
2 - The University Of British Columbia, Botany, 3529 - 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
3 - USDA-ARS Red River Valley Agricultural Research Center, Sunflower and Plant Biology Research, 1307 18th Street North, Fargo, ND, 58102, USA
4 - University Of British Columbia, Department Of Botany, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada

Keywords:
Abiotic Stress
crop
flooding
genome-wide association study (GWAS)
Sunflower
trade-offs.

Presentation Type: Oral Paper
Session: CWR1, Crops and Wild Relatives
Location: Tucson D/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 9:30 AM
Number: CWR1007
Abstract ID:604
Candidate for Awards:None