title: Response-based selection of barley cultivars and legume species for complementarity: Root morphology and exudation in relation to nutrient source.
abstract: Phosphorus (P) and nitrogen (N) use efficiency may be improved through increased biodiversity in agroecosystems. Phenotypic variation in plants' response to nutrient deficiency may influence positive complementarity in intercropping systems. A multicomponent screening approach was used to assess the influence of P supply and N source on the phenotypic plasticity of nutrient foraging traits in barley (H. vulgare L.) and legume species. Root morphology and exudation were determined in six plant nutrient treatments. A clear divergence in the response of barley and legumes to the nutrient treatments was observed. Root morphology varied most among legumes, whereas exudate citrate and phytase activity were most variable in barley. Changes in root morphology were minimized in plants provided with ammonium in comparison to nitrate but increased under P deficiency. Exudate phytase activity and pH varied with legume species, whereas citrate efflux, specific root length, and root diameter lengths were more variable among barley cultivars. Three legume species and four barley cultivars were identified as the most responsive to P deficiency and the most contrasting of the cultivars and species tested. Phenotypic response to nutrient availability may be a promising approach for the selection of plant combinations for minimal input cropping systems.
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK. Electronic address: Courtney.Giles@hutton.ac.uk.
authors.forename: Courtney D
authors.initials: CD
authors.lastname: Giles
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Lawrie K
authors.initials: LK
authors.lastname: Brown
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Michael O
authors.initials: MO
authors.lastname: Adu
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Malika M
authors.initials: MM
authors.lastname: Mezeli
authors.affiliation: Wagga Wagga Agricultural Institute, Wagga Wagga NSW, Australia.
authors.forename: Graeme A
authors.initials: GA
authors.lastname: Sandral
authors.affiliation: CSIRO Agriculture, Canberra ACT, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Renate
authors.initials: R
authors.lastname: Wendler
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Shand
authors.affiliation: Lancaster University, Lancaster Environment Centre, Lancaster, LA1 4YQ, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Menezes-Blackburn
authors.affiliation: Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, UK.
authors.forename: Tegan
authors.initials: T
authors.lastname: Darch
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Marc I
authors.initials: MI
authors.lastname: Stutter
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: David G
authors.initials: DG
authors.lastname: Lumsdon
authors.affiliation: Lancaster University, Lancaster Environment Centre, Lancaster, LA1 4YQ, UK.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, UK.
authors.forename: Martin S A
authors.initials: MS
authors.lastname: Blackwell
authors.affiliation: Lancaster University, Lancaster Environment Centre, Lancaster, LA1 4YQ, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Wearing
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Patricia
authors.initials: P
authors.lastname: Cooper
authors.affiliation: Lancaster University, Lancaster Environment Centre, Lancaster, LA1 4YQ, UK.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Haygarth
authors.affiliation: James Hutton Institute, The James Hutton Institute, Aberdeen, AB15 8QH and Dundee, DD2 5DA, Scotland, UK.
authors.forename: Timothy S
authors.initials: TS
authors.lastname: George
mesh_terms: D010832:6-Phytase / Q000378:metabolism; D000383:Agriculture; D064751:Ammonium Compounds / Q000378:metabolism; D001692:Biological Transport; D019343:Citric Acid / Q000378:metabolism; D007887:Fabaceae / Q000235:genetics / Q000378:metabolism*; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010641:Phenotype; D010758:Phosphorus / Q000172:deficiency / Q000378:metabolism*; D053147:Plant Exudates / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D053147:Plant Exudates; D010940:Plant Proteins; D010758:Phosphorus; D019343:Citric Acid; D010832:6-Phytase; D009584:Nitrogen
keywords: Barley; Exudation; Legumes; Plant nutrition; Root morphology