Carbon and nitrogen partitioning during the post-anthesis period is conditioned by N fertilisation and sink strength in three cereals

Further knowledge of the processes conditioning nitrogen use efficiency (NUE) is of great relevance to crop productivity. The aim of this paper was characterise C and N partitioning during grain filling and their implications for NUE. Cereals such as bread wheat (Triticum aestivum L. cv Califa sur), triticale (×Triticosecale Wittmack cv. Imperioso) and tritordeum (×Tritordeum Asch. & Graebn line HT 621) were grown under low (LN, 5mm NH4NO3) and high (HN, 15mm NH4NO3) N conditions. We conducted simultaneous double labelling (12CO2 and 15NH4 15NO3) in order to characterise C and N partitioning during grain filling. Although triticale plants showed the largest total and ear dry matter values in HN conditions, the large investment in shoot and root biomass negatively affected ear NUE. Tritordeum was the only genotype that increased NUE in both N treatments (NUEtotal), whereas in wheat, no significant effect was detected. N labelling revealed that N fertilisation during post-anthesis was more relevant for wheat and tritordeum grain filling than for triticale. The study also revealed that the investments of C and N in flag leaves and shoots, together with the 'waste' of photoassimilates in respiration, conditioned the NUE of plants, and especially under LN. These results suggest that C and N use by these plants needs to be improved in order to increase ear C and N sinks, especially under LN. It is also remarkable that even though tritordeum shows the largest increase in NUE, the low yield of this cereal limits its agronomic value. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

Bibliographic Details

Main Authors:	Aranjuelo, Iker, Cabrera-Bosquet, Llorenç, Araus, José Luis, Nogués, Salvador
Format:	artículo biblioteca
Published:	Thieme 2013
Subjects:	Wheat, Grain filling, 15N, Partitioning, N use efficiency, Isotopic labelling, 13C,
Online Access:	http://hdl.handle.net/10261/97209
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