SOYBEAN GENETIC MANAGEMENT AND UTILIZATION
Location: Soybean/maize Germplasm, Pathology, and Genetics Research
Title: Soybean Cultivar Variation in Response to Elevated Ozone Concentration
Submitted to: Biennial Conference on Molecular and Cellular Biology of the Soybean
Publication Type: Abstract Only
Publication Acceptance Date: July 9, 2008
Publication Date: July 20, 2008
Citation: Betzelberger, A., Mcgrath, J.M., Gillespie, K.M., Nelson, R.L., Ainsworth, E.A. 2008. Soybean Cultivar Variation in Response to Elevated Ozone Concentration [abstract]. In: Proceedings of the 12th Biennial Conference on Molecular and Cellular Biology of the Soybean, July 20-23, 2008, Indianpolis, IN. 2008 CDROM.
Crop losses to ozone damage are conservatively estimated to cost $1 to $3 billion in the U.S. These costs will rise as surface-level ozone increases over this century. A critical step in maximizing soybean yield in a future of rising tropospheric ozone is identifying variation in cultivar responses, which depends upon rapid physiological and molecular screens for ozone tolerance and sensitivity. The aim of this study was to test the response of 10 soybean cultivars to growth at elevated ozone concentrations under field conditions at the Soybean Free Air Concentration Enrichment (SoyFACE) facility (www.soyface.uiuc.edu). Throughout the season, we compared photosynthesis, leaf area index, chlorophyll fluorescence, and the antioxidant capacity of 10 soybean cultivars grown at ambient ozone (41 ppb) and elevated ozone (83 ppb). All cultivars showed a significant decrease in seed yield, ranging from an 11.2% loss in Loda to a 36.4% loss in IA3010. Maximum leaf area index and the antioxidant capacity of soybean cultivars were not consistently affected by growth at elevated ozone. However, light-saturated photosynthesis was significantly reduced (p<0.05) by 11.3% on average for all cultivars across the growing season. Stomatal conductance to water vapor was also significantly reduced (p<0.001) by 15% in elevated ozone. Both photosynthesis and the quantum yield of photosystem II were significantly correlated with seed yield in the cultivars, suggesting that these measures may be good physiological markers for yield response to elevated ozone. Future work will investigate variation in the molecular response of soybean cultivars to elevated ozone.