Nitrogen use efficiency and remobilization in wheat and barley plants exposed to waterlogging at different developmental stages

DE SAN CELEDONIO RP; ABELEDO LG; STRIKER GA; MIRALLES DJ

Santa Fe

Congreso; XXXIII Argentinian Meeting of Plant Physiology; 2021

Sociedad Argentina de Fisiología Vegetal

Waterlogging decreases grain yield in wheat and barley, however, its effect on plant N traits have not been thoroughly analyzed. The objective of the study was to evaluate the N utilization efficiency (NUE) and the partitioning to grains in wheat and barley plants exposed to different waterlogging period throughout the phenological cycle. Two pot experiments, under contrasting environmental conditions, were performed exposing wheat and barley plants to waterlogging events during 15-20 days at five different developmental stages, from emergence to physiological maturity. A control well-watered treatment was included. Grain N concentration, grain N yield, biomass N concentration at both anthesis and maturity, NUE (grain yield/ total N content in above-ground biomass at maturity), and N remobilization were measured. Both species responded similarly to waterlogging for most N traits. Reductions in grain N yield due to waterlogging were different depending on the moment of occurrence. The greatest reductions in grain N yield (46-77% respect to the control) were for waterlogging from beginning of stem elongation to anthesis, which also showed the highest reductions in N remobilization, N uptake at maturity, and N partitioning to the grains, but only a slight decrease in NUE. Grain N concentration raised drastically (up to 45 mg N g DW-1) when grain yield was minimal. N content at maturity was linear and positively related to the total biomass (R2=0.89 p