Research article - Peer-reviewed, 2006
Phosphorus, nitrogen and their interactions affect N-2 fixation, N isotope fractionation and N partitioning in Hippophae rhamnoides
Gentili, FAbstract
The interactive effects of varying phosphorus and nitrogen supplies on N-2 fixation, N isotope fractionation during N uptake, and N partitioning among plant parts were studied in the actinorhizal plant Hippophae rhamnoides L. (sea buckthorn). Plants were grown for six weeks after inoculation with the N-2-fixing actinomycete Frankia and differences in N accumulation were used to quantify N-2 fixation. N-15 natural abundance was analysed to study N isotope fractionation in specific plant parts in plants receiving different levels of N and P. Furthermore, the root system was split to study N isotope fractionation in roots supplied with different levels of N and P. Phosphorus stimulated N-2 fixation by direct effects on nodule dry matter and nodule function, rather than indirectly via plant growth. Phosphorus also stimulated N uptake from solution and influenced N isotope fractionation during N uptake. The inclusion of N-15 natural abundance analyses made it possible to detect P effects on N uptake, fractionation and N-2 fixation even though the plants used both N-2 fixation and combined N as N sourcesKeywords
Hippophae rhamnoides; isotope fractionation; nitrogen; 15N; N2 fixation; phosphorusPublished in
Symbiosis2006, volume: 41, number: 1, pages: 39-45
Publisher: INT SCIENCE SERVICES/BALABAN PUBLISHERS
Authors' information
Swedish University of Agricultural Sciences, Department of Agricultural Research for Northern Sweden
UKÄ Subject classification
Landscape Architecture
Horticulture
Agricultural Science
Food Science
URI (permanent link to this page)
https://res.slu.se/id/publ/8181