Physiological response of four wild Poa to soil pH

To investigate the mechanism by which soil pH affects physiological characteristics of wild bluegrass and to determine the optimum growth pH for wild bluegrass, the physiological indicators of four wild bluegrasses collected in Gansu Province were determined under 8 pH treatments. The results showed that in the range of 3 to 10, with an increase in pH, relative membrane permeability, free proline(Pro), soluble sugar(SS), and MDA and POD activity of the four wild bluegrasses showed first a decrease and then an increase, whereas the soluble protein content(SP) and activity of superoxide dismutase(SOD) and catalase(CAT) showed an opposite trend. The optimal pH values, in which damage to the bluegrass was minimal, was 7 for Kentucky bluegrass, small medicine bluegrass, and annual bluegrass, and 6 for hard bluegrass. These results provide information for the maintenance and management of Kentucky bluegrass lawns, as well as the introduction and domestication of wild Kentucky bluegrass.