Using FACE Systems to Screen Wheat Cultivars for Yield Increases at Elevated CO2

Abstract

Because of continuing increases in atmospheric CO 2 , identifying cultivars of crops with larger yield increases at elevated CO 2 may provide an avenue to increase crop yield potential in future climates. Free-air CO 2 enrichment (FACE) systems have most often been used with multiple replications of each CO 2 treatment in order to increase confidence in the effect of elevated CO 2 . For screening of cultivars for yield increases at elevated CO 2 , less precision about the CO 2 effect, but more precision about cultivar ranking within CO 2 treatments is appropriate. As a small-scale test of this approach, three plots, each of four cultivars of wheat, were grown in single FACE and control plots over two years, and the cultivar rankings of yield at elevated and ambient CO 2 were compared. Each replicate plot was the size used in traditional cultivar comparisons. An additional test using four smaller replicate plots per cultivar within one FACE and one ambient plot was used to compare nine cultivars in another year. In all cases, elevated CO 2 altered the ranking of cultivars for yield. This approach may provide a more efficient way to utilize FACE systems for the screening of CO 2 responsiveness.

Effects of Elevated CO2 on Wheat Yield: Non-Linear Response and Relation to Site Productivity

“…The eCO 2 wheat yield response may differ between cultivars due to the variable sink strength, which can be explored with screening strategies, e.g., in FACE facilities [51], both to identify more responsive cultivars, but also to better understand the link between genetics and traits related to high grain yield. If grain number is differently affected by eCO 2 in different wheat cultivars this could be considered in breeding programs, while, based on our investigation, it seems not to be a promising strategy to search variation in the eCO 2 response on grain mass and harvest index among existing cultivars.…”

Structural and functional changes in coffee trees after 4 years under free air CO2 enrichment

“…Artificial facilities such as growth chambers and open top chambers (Kimball, 1992) give us the opportunity to study mostly short-term responses to elevated air [CO 2 ], here refererred to as e[CO 2 ]. On the other hand, free air CO 2 enrichment (FACE) systems have been developed to support mid-to long-term studies of physiological responses to e[CO 2 ], such as of sorghum (Cousins et al, 2001), soybean (Bishop et al, 2015), wheat (Bunce, 2017), tree species (Koike et al, 2015) and even ecological systems (Macháčová, 2010).…”

Crop Adaptation: Weedy and Crop Wild Relatives as an Untapped Resource to Utilize Recent Increases in Atmospheric CO2

“…There is another genetic approach that is becoming recognized as a potential adaptation tool: the selection of intra-specific variation in seed yield among C 3 crop cultivars in response to projected increases in atmospheric CO 2 . Such an approach is being used to determine CO 2 sensitivity in conjunction with economic yield for cassava [8], rice [9], soybean [10], wheat [11], inter alia. At present, there is ample evidence that considerable variation exists within crop cultivars for anticipated increases in CO 2 and that selection for such variation holds promise as an adaptive means to increase crop yields.…”