EFFECTS OF CADMIUM AND HIGH TEMPERATURE ON CHLOROPHYLL AND MINERAL NUTRIENT CONTENTS IN Triticum aestivum L. SEEDLINGS

Wheat plays a particularly important role in the human diet. Environmental stresses negatively affect wheat development and yield. This study was conducted to determine the effects of high temperature-cadmium interactions on total chlorophyll content, chlorophyll a / chlorophyll b ratio as well as cadmium and mineral nutrient contents (potassium, magnesium, zinc, calcium) in wheat seedlings. Seedlings belong to two varieties of bread wheat (Triticum aestivum L.) named Dagdas and ES-14 were treated with different concentrations of cadmium (Cd) (0, 15, 75 ppm), under different (24/16 degrees C and 40/30 degrees C daytime/night-time) temperature conditions. The total chlorophyll increased in the Dagdas and decreased in the ES-14 in response to the high-temperature treatment (40/30 degrees C). Cadmium caused a decrease in the Chlorophyll a/b ratio in varieties at high-temperature conditions. The accumulation of cadmium and uptake of other minerals in shoots differed depending on the wheat variety and cadmium-temperature interaction. Cadmium accumulation in shoots increased in response to the cadmium treatments. Cadmium accumulation decreased at the 40/30 degrees C temperature compared to that at 24/16 degrees C temperature. Calcium accumulation increased in shoots as a response to high temperature in both varieties. In both varieties, the potassium content increased in response to cadmium (15 mu M) and high temperature.