title: Potential to breed for mycorrhizal association in durum wheat.
abstract: The selection of genotypes under high soil fertility may alter the effectiveness of mycorrhizal symbioses naturally forming between crop plants and the mycorrhizal fungi residing in cultivated fields. We tested the hypothesis that the mycorrhizal symbiosis of 5 landraces functions better than the mycorrhizal symbiosis of 27 cultivars of durum wheat that were bred after the development of the fertilizer industry. We examined the development of mycorrhiza and the response of these genotypes to mycorrhiza formation after 4 weeks of growth under high and low soil fertility levels in the greenhouse. The durum wheat genotypes were seeded in an established extraradical hyphal network of Rhizophagus irregularis and in a control soil free of mycorrhizal fungi. The percentage of root length colonized by mycorrhizal fungi was lower in landraces (21%) than in cultivars (27%; P = 0.04) and in the most recent releases (29%; P = 0.02), which were selected under high soil fertility levels. Plant growth response to mycorrhiza varied from -36% to +19%. Overall, durum wheat plant breeding in Canada has increased the mycorrhizal development in wheat grown at a low soil fertility level. However, breeding had inconsistent effects on mycorrhizal development and has led to the production of cultivars with patterns of regulation ranging from unimproved to inefficient.
authors.affiliation: a Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.|b Crop Diversification Centre South, Alberta Agriculture and Forestry, Brooks, AB T1R 1E6, Canada.
authors.forename: Walid
authors.initials: W
authors.lastname: Ellouze
authors.affiliation: a Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.
authors.forename: Chantal
authors.initials: C
authors.lastname: Hamel
authors.affiliation: a Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.
authors.forename: R M
authors.initials: RM
authors.lastname: DePauw
authors.affiliation: a Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.
authors.forename: R E
authors.initials: RE
authors.lastname: Knox
authors.affiliation: a Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Cuthbert
authors.affiliation: a Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.|c Department of Agronomy, Iowa State University, Ames, IA 50011, USA.
authors.forename: Asheesh K
authors.initials: AK
authors.lastname: Singh
mesh_terms: D005838:Genotype; D038821:Mycorrhizae / Q000502:physiology*; D000069600:Plant Breeding; D018517:Plant Roots / Q000382:microbiology; D013559:Symbiosis / Q000502:physiology; D014908:Triticum / Q000254:growth & development* / Q000382:microbiology
keywords: arbuscular mycorrhizal symbiosis; blé dur; durum wheat; growth response; réaction de croissance; symbiose mycorhize à arbuscules