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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #354254
Title: Greater heritability of photosynthesis in maize grown under elevated ozone

Author
item CHOQUETTE, NICOLE - University Of Illinois
item WERTIN, TIMOTHY - University Of Illinois
item OGUT, FUNDA - University Of Florida
item MONTES, CHRISTOPHER - University Of Illinois
item SORGINI, CRYSTAL - University Of Illinois
item MORSE, ALISON - University Of Florida
item BROWN, PATRICK - University Of Illinois
item MCINTYRE, LAUREN - University Of Florida
item LEAKEY, ANDREW D B - University Of Illinois
item Ainsworth, Elizabeth - Lisa

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Tropospheric ozone (O3) pollution is estimated to reduce maize yields up to 10% in the US. O3 causes damage to cellular processes by forming reactive oxygen species that lead to reductions in photosynthetic capacity, accelerated leaf senescence, and ultimately a decrease in reproductive and economic yield. Thus, identifying genetic variation in the response of photosynthesis to elevated O3 concentration ([O3]) is a crucial first step towards breeding for O3 tolerance. Forty-five diverse maize hybrids comprising a half-diallel design in a replicated field experiment (n=4) under ambient (~40 ppb) and elevated [O3] (~100 ppb) in 2016 and 2017. A high throughput gas exchange protocol was developed to rapidly assess photosynthesis (800 leaves in 4 days). There was significant additive genetic variation in light-saturated photosynthetic CO2 uptake, and an increase in additive variance from the response of photosynthesis in elevated [O3]. Hybrid crosses with parents NC338 and Hp301 were particularly sensitive to O3. Narrow sense heritability (hn2) for photosynthesis was substantially greater at elevated [O3] (2016: 67.8%; 2017: 49.9%) compared to ambient [O3] (2016: 22.2%; 2017: 31.5%). The increase in additive variance suggests that there are novel loci active in response to [O3] that can be selected upon. The high heritability of photosynthesis indicates the potential for phenotypic selection to improve maize photosynthesis in both ambient and elevated [O3].