Response of strawberry to inoculation with arbuscular mycorrhizal fungi under very high soil phosphorus conditions.
A field study was done to assess the potential benefit of arbuscular mycorrhizal (AM) inoculation of elite strawberry plants on plant multiplication, under typical strawberry nursery conditions and, in particular, high soil P fertility (Mehlich-3 extractible P=498 mg kg(-1)). Commercially in vitro propagated elite plants of five cultivars ('Chambly,' 'Glooscap,' 'Joliette,' 'Kent,' and 'Sweet Charlie') were transplanted in noninoculated growth substrate or in substrate inoculated with Glomus intraradices or with a mixture of species (G. intraradices, Glomus mosseae, and Glomus etunicatum) at the acclimation stage and were grown for 6 weeks before transplantation in the field. We found that AM fungi can impact on plant productivity in a soil classified as excessively rich in P. Inoculated mother plants produced about 25% fewer daughter plants than the control in Chambly (P=0.03), and Glooscap produced about 50% more (P=0.008) daughter plants when inoculated with G. intraradices, while the productivity of other cultivars was not significantly decreased. Daughter plant shoot mass was not affected by treatments, but their roots had lower, higher, or similar mass, depending on the cultivar-inoculum combination. Root mass was unrelated to plant number. The average level of AM colonization of daughter plants produced by noninoculated mother plants did not exceed 2%, whereas plants produced from inoculated mothers had over 10% of their root length colonized 7 weeks after transplantation of mother plants and approximately 6% after 14 weeks (harvest), suggesting that the AM fungi brought into the field by inoculated mother plants had established and spread up to the daughter plants. The host or nonhost nature of the crop species preceding strawberry plant production (barley or buckwheat) had no effect on soil mycorrhizal potential, on mother plant productivity, or on daughter plant mycorrhizal development. Thus, in soil excessively rich in P, inoculation may be the only option for management of the symbiosis.
Stewart
L I
LI
Department of Natural Resource Sciences, McGill University, 21 111 Lakeshore Rd., Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada. lstewa2@po-box.mcgill.ca.
Hamel
C
C
SPARC Agriculture and Agri-Food Canada, P.O. Box 1030, Airport Rd., Swift Current, SK, S9H 3X2, Canada.
Hogue
R
R
IRDA, 2700 Einstein, Ste-Foy, QC, G1P 3W8, Canada.
Moutoglis
P
P
Premier Tech Inc., 1, avenue Premier, Rivière-du-Loup, QC, G5R 6C1, Canada.
D018533:Biomass; D031985:Fragaria / Q000254:growth & development* / Q000382:microbiology*; D005658:Fungi / Q000254:growth & development*; D038821:Mycorrhizae / Q000254:growth & development*; D010758:Phosphorus / Q000032:analysis*; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D036226:Seedlings / Q000254:growth & development; D012987:Soil / Q000032:analysis*
D012987:Soil; D010758:Phosphorus