جذب پتاسيم و منيزيم در گياه ذرت ميكوريزايي تحت مقادير مختلف پتاسيم و منيزيم

The uptake of Potassium and Magnesium in Mycorrhizal Maize Under Different Concentrations of Mg and K

Mycorrhizal colonization improves uptake of nutrients as well as increase it. In this research effect of VAM (Vesicular- Arbuscular mycorrhiza) colonization on uptake of potassium and magnesium were studied. This experiment was performed natural soil containing spores of Glomus spp. Mycorrhizal spores were exposed to 4 concentrations of K solution, i. e. 240 (soil K content), 360 and 480 mg/L and 3 concentrations of Mg, i.e. 4.8 (soil Mg content), 7.2 and 9.6 meq/L concurrently. The plants were watered every 4 days for 16 days with 50 ml distilled water. A pot with sterilized soil was used as negative control. To study the mycorrhizal colonization, very thin longitudinal sections of plant roots (>lmm in diam.) were prepared manually and stained with lactophenol-cottonblue. Mycorrhizal percentage was determined by the grid-line intersect method. To measure the content of Mg and K the atomic absorption method was used. Mycorrhizal colonization increased Mg uptake but decreased K uptake. The maximum Mg content and minimum K content were observed in root and shoot when K (360 mg/L) and Mg (7.2 meq/L) were added to the pots concurrently. Regarding to interaction between VAM and these elements, by regulation of Mg and K in rhizosphere, the mycorrhizal colonization in plants can be increased and through this way the plant nutrient status aiming resistance against stresses of environment can be changed.