Data from: Source-sink relationships during grain filling in wheat in response to various temperature, water deficit and nitrogen deficit regimes

Grain filling is a critical process for improving crop production under
adverse conditions caused by climate change. Here, using a quantitative
method, we quantified post-anthesis source-sink relationships of a large
data set to assess the contribution of remobilized pre-anthesis
assimilates to grain growth for both biomass and nitrogen. The data set
came from 13 years’ semi-controlled field experimentation, in which six
bread wheat genotypes were grown at plot scale under contrasting
temperature, water, and nitrogen regimes. On average, grain biomass was
~10% higher than post-anthesis aboveground biomass accumulation across
regimes and genotypes. Overall, the estimated relative contribution (%) of
remobilized assimilates to grain biomass became increasingly significant
with increasing stress intensity, ranging from virtually nil to 100%. This
percentage was altered more by water and nitrogen regimes than by
temperature, indicating the greater impact of water or nitrogen regimes
relative to high temperatures under our experimental conditions.
Relationships between grain nitrogen demand and post-anthesis nitrogen
uptake were generally insensitive to environmental conditions, as there
was always significant remobilization of nitrogen from vegetative organs,
which helped to stabilize the amount of grain nitrogen. Moreover,
variations in the relative contribution of remobilized assimilates with
environmental variables were genotype-dependent. Our analysis provides an
overall picture of post-anthesis source-sink relationships and
pre-anthesis assimilate contributions to grain filling across
(non-)environmental factors, and highlights that designing wheat adaption
to climate change should account for complex multi-factor interactions.