Physiological and morphological effects of lead stress on bread wheat varieties (Tosunbey, Ceyhan 99) grown in Gaziantep and determination of lead tolerance levels

In this research, physiological and morphological changes caused by different lead concentrations (0, 10, 100 mg/L), one of toxic metals, on bread wheat varieties Tosunbey and Ceyhan 99 were investigated. Important morphological symptoms did not occure in control plants, while local browning and chlorosis were observed on leaves at 100 mg/L lead concentration. It is determined by root and shoot lengths and weight measurements that lead stress inhibited growth and development in wheat varieties. Pb concentrations of root and shoot of wheat varieties increased by applied Pb concentration. When two varieties were compared, highest Pb concentration in root and shoot was measured at 100 mg/L in Ceyhan 99. Lead stress also decreased pigment amounts of wheat varieties. In both varieties, however, reduction in carotenoid amounts was not important. Protein amounts decreased in root and shoot of both wheat varieties by raising Pb application. Phenolic compound amounts reduced in root and shoot tissues of Tosunbey, while increases was determined in Ceyhan 99. General increase in ascorbic acid amount, enhancement of non-protein ?SH group and proline amounts by increasing Pb accumulation in tissues of wheat varieties may show their roles in lead stress.