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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #306662
Title: Is there the potential to adapt soybean (Glycine max Merr.) to future [CO2]? An analysis of the yield response of 18 genotypes in free air CO2 enrichment

Author
item BISHOP, K - University Of Illinois
item LONG, S - University Of Illinois
item BETZELBERGER, AMY - University Of Illinois
item Ainsworth, Elizabeth - Lisa

Submitted to: Plant Cell and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2014
Publication Date: 10/26/2014
Citation: Bishop, K.A., Long, S.P., Betzelberger, A.M., Ainsworth, E.A. 2014. Is there the potential to adapt soybean (Glycine max Merr.) to future [CO2]? An analysis of the yield response of 18 genotypes in free air CO2 enrichment. Plant Cell and Environment. 38(9):1765-1774. doi: 10.1111/pce.12443.

Interpretive Summary: Rising atmospheric CO2 increases photosynthesis in soybean, stimulating growth and seed yield. This effect of rising CO2 has the potential to offset some of the negative effects of global climate change on crop production. However, in order to adapt soybean to a world with higher CO2 concentrations, significant variation in the response among different varieties is required. This study investigated the response of 18 soybean varieties to elevated carbon dioxide concentrations (CO2) in a farm field setting. There was variation in the response of seed yield in the genotypes, ranging from no stimulation to a 22% increase in yield. There was also consistency from year to year in the varieties that were the most and least responsive to elevated CO2 concentrations. This study shows that there is genetic variation in soybean response to elevated CO2 that could be used to breed for more responsive lines in the future.

Technical Abstract: Rising atmospheric [CO2] is a uniform and global change that increases C3 photosynthesis by suppressing the oxygenation reaction of Rubisco and accelerating carboxylation. This has the potential to provide some offset to the negative effects of global change on crop yields. However, under field conditions, soybean (Glycine max Merr. L.) and other major C3 crops fail to realize a yield increase equivalent to that anticipated from the observed increase in photosynthesis. If interspecific genetic variation in yield responsiveness to rising [CO2] can be found, this would provide an opportunity to breed more responsive crop genotypes. Here we report on a multi-year study of 18 soybean genotypes for responsiveness to season-long elevated [CO2] (550 ppm) under fully open-air replicated field conditions. On average, elevated [CO2] stimulated seed yield by ~8% and total shoot mass by ~23%. However, responses varied significantly among genotypes from no stimulation in yield to a 22% increase. There was consistency from year to year in the cultivars that were most and least responsive to elevated [CO2], suggesting the potential for heritability of CO2 response. The results show for the first time, under open-air field conditions, the existence of genetic variation that could be used in breeding more [CO2] responsive soybean cultivars, subject to subsequent proof of heritability.