" "understanding the variability in plant responses to elevated concentrations of atmospheric CO2 is of great importance in breeding or selecting the best genotypes for future climatic conditions"
... eight Italian researchers set out to investigate the response of nine durum wheat cultivars (Achille, Cappelli, Creso, Ofanto, Rusticano, San Carlo, Simento, Spartaco and Svevo) to a simulated increase in atmospheric CO2 and temperature.
The experimental treatment (ETEC) included temperatures that were +2.5 °C above control and elevated CO2 concentrations twice that of control conditions (i.e., 800 ppm).
... total dry biomass was enhanced in 8 of the 9 cultivars (the ninth showed no change), albeit only significantly in two (Cappelli and Simeto, with 26% and 57% increases, respectively).
The most significant parameter, however, when it comes to feeding the world is grain yield. ... there was no significant difference in this variable among treatments in five of the cultivars. In contrast, four cultivars experienced significant increases in response to the high temperatures and atmospheric CO2 level.
Cappelli, Rusticano, San Carlo and Simeto grain yields were enhanced by 26%, 44%, 48% and 61%, respectively, relative to their controls.
... none of the nine cultivars experienced declining yields while four experienced significant increases. ... farmers (will) select and grow the genotypes that are most responsive to rising temperatures and atmospheric CO2 concentrations."