Influence of Glomus fasciculatus mycorrhizae on some physical and chemical characteristics of Platanus occidentalis seedlings

Abstract

Inoculation of Platanus occidentalis seedlings with Glomus fasciculatus significantly increased plant dry weight and foliar phosphorus (P) concentration when compared with the uninoculated control. After 12 weeks inoculated seedlings were 73% taller and 200% greater in total dry weight. The largest dry weight increase was recorded for foliage (212%) followed in order by stem (202%) and root (171%). Averaged overall nutrient treatments, foliar P concentration was 22% greater for the inoculated seedlings. Nutrient regimes representing 1×, 2×, and 4× Hoagland's No. 2 solution and a control significantly influenced seedling height, dry weight, percentage of foliar N, P, and K, and the degree of root colonization. Maximum growth and foliar nutrient concentrations were associated with the 2× Hoagland's nutrient regime followed in order by the 4× and 1× nutrient treatments and the control. Degree of root colonization by G. fasciculatus increased from 42% of the root length in the unfertilized control to 48% at the 1× Hoagland's regime and sharply declined at the 2× and 4× levels. Total dry weight of inoculated seedlings was significantly greater than the noninoculated control at each nutrient level. Incremental differences were 2.71, 4.03, 4.37, and 3.08 g for the control, 1×, 2×, and 4× Hoagland's nutrient regimes, respectively. Seedling growth attributed to G. fasciculatus is directly related to degree of mycorrhizal colonization and inversely related to the amount of extractable soil P.