The effect of magnesium ions on the vesicular—arbuscular mycorrhizal infection of maize roots

Abstract

SUMMARYThe effect of magnesium sulphate on the colonization of maize roots by a vesicular-arbuscular mycorrhizal fungus was studied in hydroponic culture. Increased concentration of MgSO4 in the nutrient solution caused an increase in the percentage of root length infected. The highest infection levels were found when nutrient solutions contained 5-84-11-68 mmol 1"^ of MgSO^. Root colonization was stimulated by the increased concentration of magnesium but not calcium or potassium ions in the nutrient solution. No significant difference occurred in the percentage of root length infected when magnesium chloride was replaced by magnesium sulphate. A broad range of magnesium sulphate concentrations did not cause significant differences in plant biomass. The stimulation of root colonization by magnesium cannot be explained by changes in pH or osmotic pressure of the nutrient solution.

Potential of Cover Crops in Promoting Mycorrhizal Diversity and Soil Quality in Organic Farms

“…was most commonly found in sunn hemp and lablab treatments, where higher densitties of Gigaspora occurred in the sudangrass treatment. Similar results of higher density of Glomus in soils with high magnesium concentration and high Gigaspora density in low soil magnesium concentration has been reported in previous studies (Schenck & Siqueira, 1987;Gryndler, 1992). The overall diversity of mycorrhizal fungi, however, was similar for the different cover crops and was lower in the control treatment.…”

Species-dependent partitioning of C and N stable isotopes between arbuscular mycorrhizal fungi and their C3 and C4 hosts

“…Plants were grown in a greenhouse with day:night temperatures of 30:15 C and irrigation by full saturation of the substrate three times a week. A P2N3 nutrient solution for hydroponics (Gryndler et al, 1992), with 1.25 mM Ca(NO 3 ) 2 and 2.37 mM KNO 3 as N source, was applied once a week, 2e3 h before irrigation to prevent leakage (50 mL per pot and, after seedling establishment, 100 mL per pot). AM roots (hereafter simply referred to as roots) and shoot biomass were harvested from each plant three months after inoculation, dried at 80 C for 72 h, and weighed.…”

Alleviation of Mycorrhiza to Magnesium Deficiency in Trifoliate Orange: Changes in Physiological Activity

“…under high Mg level conditions. Therefore, Mg may have a specific biological effect on root AM colonization (Gryndler et al, 1992).…”