Effects of heavy metal cadmium on morphology and physiology of Festuca arundinacea seedlings

A comprehensive evaluation of 20 Festuca arundinacea cultivars tolerance to heavy metal cadmium (Cd) was conducted by measuring their morphological and physiological response under different Cd2+ concentrations. The results showed that survival rate, plant height, above ground biomass and leaf water content significantly decreased with the cadmium concentration increasing whereas tiller numbers firstly increased and then decreased with the cadmium concentration increasing. Two strong cadmium tolerant cultivars(M15 and M8) and two weak cadmium tolerant cultivars (M5 and M11) were screened using the standard deviation coefficient allocation weight method. And then, the physiological response of these 4 cultivars to Cd2+ including the activities of peroxidase (POD) and catalase (CAT) and the contents of chlorophyll and proline (Pro) were measured. With the cadmium concentration increasing, the activities of POD and CAT of 2 strong cadmium tolerant cultivars increased whereas those of 2 weak cadmium tolerant cultivars firstly increased and then decreased. With the cadmium concentration increasing, the chlorophyll contents of all tested cultivars decreased and Pro contents of all tested cultivars increased.