title: Is there potential to adapt soybean (Glycine max Merr.) to future [CO₂]? An analysis of the yield response of 18 genotypes in free-air CO₂ enrichment.
abstract: Rising atmospheric [CO2] is a uniform, global change that increases C3 photosynthesis and could offset some of the negative effects of global climate change on crop yields. Genetic variation in yield responsiveness to rising [CO2] would provide an opportunity to breed more responsive crop genotypes. A multi-year study of 18 soybean (Glycine max Merr.) genotypes was carried out to identify variation in responsiveness to season-long elevated [CO2] (550 ppm) under fully open-air replicated field conditions. On average across 18 genotypes, elevated [CO2] stimulated total above-ground biomass by 22%, but seed yield by only 9%, in part because most genotypes showed a reduction in partitioning of energy to seeds. Over four years of study, there was consistency from year to year in the genotypes that were most and least responsive to elevated [CO2], suggesting heritability of CO2 response. Further analysis of six genotypes did not reveal a photosynthetic basis for the variation in yield response. Although partitioning to seed was decreased, cultivars with the highest partitioning coefficient in current [CO2 ] also had the highest partitioning coefficient in elevated [CO2]. The results show the existence of genetic variation in soybean response to elevated [CO2], which is needed to breed soybean to the future atmospheric environment.
authors.affiliation: Department of Plant Biology, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Bishop
authors.affiliation: Department of Plant Biology, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Betzelberger
authors.affiliation: Department of Plant Biology, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.|Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Long
authors.affiliation: Department of Plant Biology, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.|Global Change and Photosynthesis Research Unit, USDA ARS, Urbana, IL, 61801, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Ainsworth
mesh_terms: D000222:Adaptation, Physiological; D002245:Carbon Dioxide / Q000494:pharmacology; D057231:Climate Change; D005838:Genotype; D007087:Illinois; D012639:Seeds; D013025:Glycine max / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D014887:Weather
chemical_list: D002245:Carbon Dioxide
keywords: atmospheric change; biomass partitioning; climate change; crop development; crop yield; food security; global change; harvest index