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

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

Crop and Pasture Science

CSIRO Publishing

Lugar: Melbourne; Año: 2022 vol. 73 p. 615 - 626

1836-0947

Although waterlogging is known to decrease grain yield in wheat and barley, a question that remains unanswered is its effect on plant N traits. This study evaluated biomass N dynamics and partitioning to grains, in wheat and barley plants subjected to waterlogging. Under contrasting environmental conditions, two pot experiments were performed exposing wheat and barley plants to waterlogging events for 15-20 days at five different developmental stages, from emergence to maturity. Grain N concentration, grain N content, biomass N concentration, N utilisation efficiency (NUE), and N remobilisation were recorded. Both species responded similarly to waterlogging for most N traits. Reductions in grain N content differed according to the moment waterlogging occurred. The greatest reductions (46-77% compared to the control) being for waterlogging from the beginning of stem elongation to anthesis, which also showed the highest reductions in N remobilisation, 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) with minimal grain yields. N concentration of above-ground biomass decreased during waterlogging, recovering control values at maturity. N content at maturity was related to the total biomass. We conclude that waterlogging differentially reduced N uptake and remobilisation to grains of wheat and barley depending on the developmental stage in which the water excess occurred, part of the response seems to be indirect, mediated by the impact of waterlogging on biomass production.