EFFECTS OF VARIED MAGNESIUM AND POTASSIUM NUTRITION ON WHEAT GROWN UNDER AMBIENT AND ELEVATED ATMOSPHERIC CARBON DIOXIDE CONDITIONS
Biological Sciences and Bioengineering, MSc. Thesis, 2014
Assoc. Prof. Dr. Levent Öztürk (Thesis Advisor), Prof. Dr. Hikmet Budak, Prof. Dr. Ersin Göğüş
Date &Time: December 26th, 2014 – 11:00 AM
Place: FENS L061
Keywords: Wheat, Elevated Carbon Dioxide, Magnesium, Potassium, Photosynthesis Parameters
Atmospheric carbon dioxide (CO2) has been continuously increasing from 280 µmol mol-1 in 1800’s up to 395 µmol mol-1 as of today and projected to elevate to some point in between 530-970 µmol mol-1 by the end of the 21st century. This study aimed to understand how low magnesium (Mg) and potassium (K) supply affects plant growth and physiology in an elevating CO2 environment using two major wheat species (Triticum aestivum cv. Adana 99 and Triticum durum cv. Sarıçanak 98) as model plants. As expected low Mg and K treatments resulted in retarded biomass production and occurrence of severe leaf deficiency symptoms. Photosynthesis rate was significantly induced by elevated CO2 treatments, however this induction was hampered by low Mg and K supply. Elevation of CO2 resulted in accumulation of carbohydrates in source leaves particularly in low-Mg and low-K plants. In plants grown with adequate Mg and K, shoot and root biomass, root length and volume were significantly increased with elevated CO2. However, growth enhancement resulting from elevated CO2 was less pronounced in low-Mg and low-K plants. Total antioxidant capacity, lipid peroxidation and membrane stability were altered by low Mg and K supply irrespective of the [CO2] treatments. Due to the detrimental effects of low Mg and K supply on phloem export of carbohydrates, photosynthesis rate, root properties linked to nutrient uptake from soil, antioxidative system and membrane structure, nutritional status of plants with Mg and K has crucial importance to take advantage of an atmosphere with elevating CO2 levels.