Elevated CO2 alters grain quality of two bread wheat cultivars grown under different environmental conditions

Fernando, Nimesha and Panozzo, Joe and Tausz, Michael and Norton, Robert M. and Neumann, Nathan and Fitzgerald, Glenn J. and Seneweera, Saman (2014) Elevated CO2 alters grain quality of two bread wheat cultivars grown under different environmental conditions. Agriculture, Ecosystems and Environment, 185. pp. 24-33. ISSN 0167-8809

Abstract

Bread wheat (Triticum aestivum L. cv. Yitpi and cv. Janz) was grown under field conditions in the Australian Grains Free-Air CO2 Enrichment (AGFACE) facility. Ambient [CO2] (a[CO2], ~384μmolmol-1) and elevated [CO2] (e[CO2], ~550μmolmol-1) were combined with two soil water levels (rain-fed and irrigated) and two times of sowing (TOS) in three consecutive years to provide six environments (2007-TOS1, 2007-TOS2, 2008-TOS1, 2008-TOS2, 2009-TOS1, 2009-TOS2). Grain samples were assessed for a range of physical, nutritional and dough rheological properties. The effect of e[CO2] on thousand grain weight (TGW) was significantly different in each growing environment: TGW was significantly increased under e[CO2] only at 2007-TOS2 (by 5%), 2009-TOS1 (by 5%) and 2009-TOS2 (by 15%) but not significantly changed under other conditions. The magnitude of reduction of grain protein concentration at e[CO2] differed among the growing environments but was highly correlated with the percentage yield stimulation under e[CO2] (r2=0.91) suggesting that grain protein concentration under e[CO2] was diluted by increased yield. Across all treatments, grain nutrient concentration was significantly reduced by e[CO2] for Fe (3.9%, 6.2%), Cu (2.2%, 3.4%), Zn (5.9%, 5.7%), Ca (5.6%, 7.3%), Mg (5.6%, 5.8%), Na (21.2%, 30.4%), S (4.4%, 4.4%), P (4.1%, 3.2%) in cv. Yitpi and Janz, respectively. Effects of e[CO2] on grain Zn, Mg and Na concentrations were dependent on the growing environment. Relative reduction of grain S, Fe, Mg, Zn, P at e[CO2] were significantly correlated with grain yield stimulation at e[CO2]. Reductions of these nutrients under e[CO2] were not fully explained by biomass dilution as the relationships differed for each nutrient. Under e[CO2], flour yield of cv. Janz was increased but that of cv. Yitpi was not changed. Even though grain protein concentrations of both cultivars were similar at e[CO2], bread volume as inferred indirectly by dough rheology parameters was 12% greater for cv. Janz (185±5cm3) than cv. Yitpi (162±4cm3) at e[CO2]. This disparity may be related to the compositional changes in wheat flour protein at e[CO2], suggesting that future breeding and adaptation strategies to improve the grain quality under e[CO2] should consider the prevailing hydro-thermal conditions.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2013 Published by Elsevier B.V. Permanent restricted access to published version in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 30 Jun 2014 22:27
Last Modified: 16 Mar 2015 06:43
Uncontrolled Keywords: elevated CO2; wheat; climate change; grain quality; protein; micro nutrient; bread quality; dough rheological properties; grain minerals
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060705 Plant Physiology
05 Environmental Sciences > 0501 Ecological Applications > 050102 Ecosystem Function
05 Environmental Sciences > 0501 Ecological Applications > 050101 Ecological Impacts of Climate Change
Socio-Economic Objective: D Environment > 96 Environment > 9603 Climate and Climate Change > 960301 Climate Change Adaptation Measures
Identification Number or DOI: 10.1016/j.agee.2013.11.023
URI: http://eprints.usq.edu.au/id/eprint/25180

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