Contribution of nitrogen fixation to first year Miscanthus × giganteus. Issue 5 (31st July 2013)

• Record Type: Journal Article
• Authors: Keymer, Daniel P.; Kent, Angela D.
• Is Part Of: Global change biology. Volume 6:Issue 5(2014)
• Page Start: 577
• Page End: 586
• Publication Date: 2013-07-31
• Subjects: Biomass energy -- Periodicals; Biomass energy -- Environmental aspects -- Periodicals; Energy crops -- Periodicals; 662.88
• DOI: 10.1111/gcbb.12095
• Languages: English
• ISSNs: 1757-1693

Abstract

<abstract abstract-type="main" id="gcbb12095-abs-0001"> <title>Abstract</title> <p>Many characteristics make <italic>Miscanthus</italic> × <italic>giganteus</italic> an appealing bioenergy feedstock in temperate North America, but the degree to which this plant species interacts with nitrogen‐fixing bacteria remains understudied. Demonstration of associative nitrogen fixation in <italic>Miscanthus</italic> would support management with minimal fertilizer inputs that is demanded of long‐term biofuel sustainability. As a first step, we investigate the role of biological nitrogen fixation in nutrition of immature <italic>Miscanthus</italic> and temporal dynamics of plant‐associated nitrogen fixers. The contribution of biological nitrogen fixation to plant nitrogen acquisition in first year <italic>Miscanthus</italic> × <italic>giganteus</italic> was estimated using a yield‐dependent <sup>15</sup>N isotope dilution model. Temporal changes in plant‐associated diazotroph relative abundance and community composition were analyzed with quantitative PCR and terminal restriction fragment length polymorphism of the <italic>nifH</italic> gene in rhizome and rhizosphere DNA extracts. We estimate 16% of new plant nitrogen was derived by nitrogen fixation during the growing season, despite non‐limiting soil nitrogen. Diazotroph communities from rhizome and rhizosphere changed with plant development and endophytic nitrogen fixers had significantly higher relative abundance and altered community composition at sampling dates in July and August. This study provides evidence for a small, but measurable, benefit of associative nitrogen fixation to first year <italic>Miscanthus</italic> × <italic>giganteus</italic> that underscores the potential and need for selection of breeding lines that maximize this trait.</p> </abstract>