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The δ 15 N of lettuce and barley are affected by AM status and external concentration of N
Author(s) -
AZCÓNG.AGUILAR ROSARIO,
HANDLEY L. L.,
SCRIMGEOUR C. M.
Publication year - 1998
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.1998.00883.x
Subject(s) - hordeum vulgare , plant species , biology , arbuscular mycorrhizal , botany , fungus , chemistry , horticulture , symbiosis , poaceae , bacteria , genetics
Mean δ 15 N of whole‐plants of lettuce and barley varied by 3‰ when given a chemically and isotopically uniform N source. This variation was related to the presence, absence and species of arbuscular mycorrhizal (AM) fungi and to external N concentration. A highly AM‐susceptible plant (lettuce) responded to treatments differently than a less susceptible one (barley). The largest change in whole plant δ 15 N was related to the experimental combination most likely to be found in field conditions: species of fungus interacting with varying external concentrations of N. The mechanisms underlying observed variations of plant δ 15 N are not understood, nor can they be approached directly using δ 15 N. However, descriptive data, such as presented here, are important to the development of a mechanistic model, because they suggest relationships for future research, using inter alia 15 N‐enriched tracers. They also confirm that plant N sources, cannot be identified using plant δ 15 N, even when the type of mycorrhizal association (endo vs. ecto) is known.