Source–sink balance of wheat determines responsiveness of grain production to increased [CO2] and water supply

Determining photosynthetic responses of forest species to elevated [CO2]: Alternatives to FACE

“…Sink limitation can be expected to become more important as source strength increases under elevated [CO 2 ] (Uddling et al, 2008). A large sink capacity has been identified as critical for maximising plant production in elevated [CO 2 ] environments (Drake et al, 1997;McCormick et al, 2008), and significant feedbacks to source activity due to sink limitation can be expected for plants with low sink strength.…”

Harvest index, a parameter conditioning responsiveness of wheat plants to elevated CO2

“…large ears in the case of cereals) will benefit more from [CO 2 ] enrichment than those with a small sink size (Manderscheid and Weigel, 1997; Aranjuelo et al ., 2009). As mentioned above, leaf C sink/source and therefore photosynthetic performance is also conditioned by the sink strength of other organs such as grains (Uddling et al ., 2008; Aranjuelo et al ., 2011). Grain filling and, by extension, grain yield are mainly sustained by assimilation and management of C and N compounds.…”

“…Grain yield may be limited by source activity, translocation from source to sink organs, and the sink activity (Borrás et al ., 2004; Uddling et al ., 2008; Foulkes et al ., 2011). It has been observed that grain filling is mostly conditioned by plant sink activity and that grain sink capacity is largely determined by source activity around anthesis (Foulkes et al ., 2007; Reynolds et al ., 2007).…”

Agroecology: Implications for Plant Response to Climate Change

“…He concluded that variation in the response of pod and seed number might be more important than photosynthetic of stem biomass response (Bunce, 2008). Uddling et al (2008) concluded that the effects of elevated CO 2 and irrigation on grain production and biomass partitioning in wheat were modified by the source-sink balance of the plant. They had observed sink limitation was the major constraint on CO 2 -induced grain yield enhancement of spring wheat.…”

“…They had observed sink limitation was the major constraint on CO 2 -induced grain yield enhancement of spring wheat. They suggested that efforts to increase photosynthetic rates before and after anthesis as a method to increase grain yield in wheat under conditions of elevated CO 2 might not produce the desired results unless source strength was considered as well (Uddling et al 2008). In a recent study from Australia on wheat, Luo et al (2009) used the APSIM-Wheat model to evaluate different adaptation strategies that included rainfall and N management.…”