Open Access

Several studies have analyzed the photosynthetic contribution of the ear to grain filling. However, its contribution in terms on nitrogen supply remains far less investigated. The nitrogen accumulated in the developing grains is supplied by remobilization of proteins from different organs of the plant. The aim of this work was to study the effect of growing conditions (optimal agronomic conditions and different levels of water and nitrogen deficit) on the potential nitrogen contribution of the spike and the different vegetative organs of the plant to the grains. To that end, natural abundance of δ15N and total N concentration in the flag leaf blade, peduncle, and different tissues of the spike (glumes and awns) were compared to values of δ15N in mature grains as well as in the total N content of grains per spike, in order to trace the origin of the nitrogen redistributed into the grains. In overall terms, δ 15N and the total N content of the flag leaf blade, peduncle, glumes and awns, correlated positively with the δ15N and the total N content of the mature kernels per spike, suggesting that all organs could be potentially exporting part of its N to the grains. In spite of that, flag leaf blade under good agronomic conditions (and thus high grain yield) was the main organ which potentially contribute to grain N, whereas under water stress conditions (low GY) were the glumes and the penduncle. Such findings indicate that growing conditions may affect the relative potential N contribution of the different plant parts to grain N.

Wheat CRP FP3 - Global partnership to accelerate genetic gain in farmers field

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