15NO3 assimilation by the field Pea Pisum sativum L.Sanoussi Attaa, b, Stephane Maltesea, Pascal Margeta and Roger Cousina
a INRA, Station de Génétique et d'Amélioration des Plantes, route de Saint Cyr, 78026 Versailles Cedex, France
b Present address: Centre Régional AGRHYMET, BP 11011 Niamey, Niger
(Received 10 January 2003; accepted 8 January 2004)
Abstract - The objectives of this study were to determine the effect of low mineral supply on plant growth and the uptake and redistribution of mineral N by different plant organs according to the period of uptake. A glasshouse study was conducted on two pea genotypes, L833 and cv. Frisson, fed without or with 4 mM NO3. Plants fed with 4 mM N were labelled for 5 days with 15N at three stages: 7 leaf stage, beginning of flowering, and beginning of seed filling. Plants were harvested at day 6 and at later stages. The results indicated for the two genotypes that supplying 4 mM N to the plants significantly increased their total dry weight up to the beginning of seed filling, whereas nodule dry weight was reduced. Genotype differences in N uptake and redistribution among plant organs were minor. When plants were labelled with 15N at early stages of growth, about 60% of total plant 15N was located in leaves. At maturity the proportion of 15N recovered in seeds was about 60% for both genotypes. When plants were labelled at the beginning of seed filling, 15N was mainly located in young organs such as upper leaves, pods and seeds. During seed fill the remobilisation of 15N to seeds occurred from all organs of the plant. At physiological maturity about 70% of 15N was located in seeds.
Key words: Pea Pisum sativum / 15N assimilation / remobilisation / redistribution / flowering / seed filling / physiological maturity
Corresponding author: Sanoussi Atta S.Atta@agrhymet.ne
© INRA, EDP Sciences 2004