Effects of elevated CO2 on grain yield and quality of wheat: results from a three-year FACE experiment

Publication Type

Journal contribution (peer reviewed)

Authors

Högy, P., Wieser, H., Köhler, P., Schwadorf, K., Breuer, J., Franzaring, J., Muntifering, R., Fangmeier, A.

Year of publication

2009

Published in

Plant Biology

ISBN / ISSN / eISSN

doi:10.1111/j.1438-8677.2009.00230.x

Page (from - to)

60-69

Spring wheat (Triticum aestivum L. cv. TRISO) was grown for three consecutive seasons in a free-air carbon dioxide (CO2) enrichment (FACE) field experiment in order to examine the effects on crop yield and grain quality. CO2 enrichment promoted aboveground biomass (+11.8%) and grain yield (+10.4%). However, predominantly adverse effects were observed on wholegrain quality characteristics. Although the thousand-grain weight remained unchanged, the size distribution was significantly shifted towards smaller grains, which may directly relate to a lower market value. Total grain protein concentration decreased significantly by 7.4% under elevated CO2, and protein and amino acid composition were altered. Corresponding to the decline in grain protein concentrations, CO2 enrichment resulted in an overall decrease of amino acid concentrations, with greater reductions for non-essential than for essential amino acids. Some minerals such as potassium, molybdenum and lead were increased, while others such as manganese, iron, cadmium and silicon were decreased, suggesting that adjustments of agricultural practices may be required to keep current grain quality standards. The concentration of fructose and fructan as well as the amounts per area of total and individual non-structural carbohydrates except for starch were significantly increased in the grains. The same holds true for the amount of lipids. With regard to mixing and rheological properties of the flour, a significant increase in gluten resistance under elevated CO2 was observed. CO2 enrichment is obviously affecting grain quality characteristics important for consumer nutrition and health, industrial processing and marketing, which have to date received little attention.