10.6084/m9.figshare.8427479.v1 Lancelot Maphosa Lancelot Maphosa Glenn J. Fitzgerald Glenn J. Fitzgerald Joe Panozzo Joe Panozzo Debra Partington Debra Partington Cassandra Walker Cassandra Walker Surya Kant Surya Kant Genotypic response of wheat under semi-arid conditions showed no specific responsive traits when grown under elevated CO<sub>2</sub> Taylor & Francis Group 2019 AGFACE CO2 genotype quality wheat yield 2019-07-02 11:53:40 Journal contribution https://tandf.figshare.com/articles/journal_contribution/Genotypic_response_of_wheat_under_semi-arid_conditions_showed_no_specific_responsive_traits_when_grown_under_elevated_CO_sub_2_sub_/8427479 <p>Atmospheric carbon dioxide (CO<sub>2</sub>) is predicted to reach 550 µmol mol<sup>−1</sup> by 2050, increasing from the current ~410 µmol mol<sup>−1</sup> concentration, and this will have an impact on wheat production and grain quality. Genetic differences in response to future CO<sub>2</sub> levels, which might be exploited for higher yield and sustainable grain quality, were investigated. Twelve diverse genotypes (11 wheat lines and 1 triticale cultivar) were grown in the Australian Grains Free-Air CO<sub>2</sub> Enrichment facility under ambient CO<sub>2</sub> (~400 µmol mol<sup>−1</sup>) and elevated CO<sub>2</sub> (eCO<sub>2</sub>) concentrations (550 µmol mol<sup>−1</sup>) in 2014 and 2015 to test for different responses to CO<sub>2</sub>. Genotype response to eCO<sub>2</sub> for the parameters measured showed strong linear relationships. eCO<sub>2</sub> increased plant height (11%), aboveground biomass (31%) and grain yield (32%) as means across all genotypes. Yield response to eCO<sub>2</sub> was driven by increases in spike number and weight. The increase in CO<sub>2</sub> caused a mean 10% decrease in grain nitrogen content and increased grain weight by 7%. Measures of bread dough quality decreased due to eCO<sub>2</sub>. Genotypes with large yield response did not show larger than mean reductions in grain %N. The apparent near-universal decline in grain %N under eCO<sub>2</sub> might be compensated for by selection of genotypes that are highly responsive to increasing yields but resist dramatic declines in grain %N. Selection for responsiveness to eCO<sub>2</sub> for yield and grain %N are likely to involve a range of co-related characteristics that balance sink and source relationships.</p>