Investigating variation in the response of photosynthetic traits to ozone pollution in maize

Ozone is the most damaging air pollutant to crops, currently reducing Midwest U.S. maize production by up to 10%, yet there has been very little effort to adapt germplasm for ozone tolerance. Ozone enters plants through stomata, reacts to form reactive oxygen species in the apoplast, and ultimately decreases photosynthetic carbon gain. Free Air Concentration Enrichment (FACE) technology is for essential evaluating the photosynthetic response of maize to elevated ozone in field conditions. This project used FACE technology to 1) investigate the heritability of photosynthesis under ambient and elevated ozone, 2) evaluate variation in physiological and biochemical responses to elevated ozone, 3) identify quantitative trait loci (QTL) for photosynthetic traits in response to elevated ozone. Overall, ozone increased the heritability of photosynthetic traits and altered genetic correlations among traits. Additionally, ozone decreased the photosynthetic capacity of maize in vitro and in vivo in diverse F1 hybrids. Finally, large effect QTLs were identified for ozone sensitivity and tolerance of photosynthetic traits to elevated ozone. This research represents the first steps toward breeding for improved photosynthesis and ozone tolerance in maize.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste