Evaluating biochemical response of some selected perennial grasses under drought stress in Iran

Native grasses are important for the enhancement of landscape. Agropyron cristatum, A.intermedium, Festuca ovina, Festuca arundinaceae, Cynodon dactylon, Bromus inermis and B. confinis are the potential sources of low maintenance turfgrasses for semi-arid regions. This greenhouse study examined the interaction of four different levels of soil water contents with 75, 50, and 25% field capacity (FC) and non-irrigation on physiological and biochemical responses of each accession. Total carbohydrate and sucrose contents of F. arundinaceae were increased significantly under non-irrigated treatment but decreased in the other genotypes. Proline, hydrogen peroxide, and total ascorbate increased in all the species under drought. Also, with decreased soil water content, H2O2 content increased up to 50% in F. arundinaceae. Protein content of F. arundinacea increased significantly under drought stress compared to the control; however, it decreased in other genotypes. Ascorbate peroxidase activities were increased in Festuca sp. and decreased in A. cristatum. It was found that F. arundinacea was able to maintain higher relative water content level and osmotic potential in non-irrigated drought treatment than B. inermis and A. cristatum. It may be speculated that the observed drought stress tolerance was associated with the ability of accumulating compatible solutes and H2O2 signaling cascade. Also, the high activity of ascorbate peroxidase resulted in protection against oxidative damage. It seems that this mechanism worked better in F. arundinacea to be used as low maintenance turfgrass.