The investigation of cadmium stress and its relation with paclobutrazol application in bread (Triticum aestivum cv. Özkan) and durum wheat (Triticum durum cv. Diyarbakir 81)

Cadmium is one of the heavy metals having negative effects on plants. Paclobutrazol, is a plant growth regulator that is known to have alleviating effect on stress factors. In this study, the effects of cadmium stress and its relation with paclobutrazol in durum wheat (Triticum durum cv. Diyarbakır 81) and bread wheat (Triticum aestivum cv. Özkan) cultivars were investigated. For this purpose, first group of seeds were imbibed in distile water and second group of seeds in 50 mg/l paclobutrazol solutions and germinated, then they were grown in hydroponic system under controlled conditions for seven days. Afterwards 0-75-100 and 200 µM cadmium was applied on first group of plants and 0-100 µM cadmium on second group of plants. At the end of the process; growth and relative water content, pigment, prolin, cadmium, malondialdehyde, soluble sugar, alpha tocopherol, ascorbic acid, glycine-betaine contents; superoxide dismutase and catalase enzyme activities of the cultivars were determined.For both of the cultivars, depending on cadmium applications growth was inhibited and relative water content increased. As a result of cadmium application; pigment content decreased; cadmium accumulation, prolin, malondialdehyde, ascorbic acid and glycine-betaine increased in both cultivars. In Diyarbakır 81 cv soluble sugar and alpha tocopherol content increased, while this effects weren't seen in Özkan cv.. Enzyme activities decreased in both cultivars at 100 and 200 µM cadmium doses. Paclobutrazol application restricted growth more in collaboration with cadmium. Paclobutrazol increased the decline of pigment content and enzyme activities which was caused by cadmium, and decreased the rise of proline, cadmium, alpha tocopherol and glycine-betaine contents. Bread cultivar Özkan was found more tolerant than durum cultivar Diyarbakır 81 against cadmium.