Effect of arbuscular mycorrhizal fungal inoculation on growth, and nutrient uptake of the two grass species, Leptochloa fusca (L.) Stapf and Sporobolus robustus Kunth, under greenhouse conditions
The aim of our work was to assess the effect of inoculation with three arbuscular mycorrhizal fungi (AMF) (Rhizoglomus aggregatum (N.C. Schenck and G.S. Sm.) Sieverd., G.A. Silva and Oeh., Funneliformis mosseae (T.H. Nicolson and Gerd.) C. Walker and A. Schüssler. and Rhizoglomus intraradices (N.C. Schenck and G.S. Sm.) Sieverd., G.A. Silva and Oehl.), and a mixed inoculum of these AMF on root colonization, biomass production, mycorrhizal dependency (MD) and shoot mineral contents of two salt tolerant grasses Leptochloa fusca L. Stapf and Sporobolus robusts Kunth. After four months of growth in a sterilized soil and greenhouse conditions, grasses inoculated with AMF showed significantly higher total biomass production than non-inoculated seedlings. MD and shoot mineral contents (especially P) varied with AMF host plants. Maximum values of MD (13%) were observed in L. fusca and S. robustus seedlings when inoculated with R. intraradices and F. mosseae, respectively. Only P contents were higher in the S. robustus/mixed-AMF combinations than the other treatments. These results demonstrate the potential benefits in our experimental conditions of AM inoculation for improving growth and P acquisition particularly in the L. fusca/ F. mosseae and S. robustus/mixed-AMF combinations.
Key words: Grass species, symbiosis, mycorrhizal dependency, mineral nutrition.