Physiological responses of bluestem, reed canarygrass and switchgrass under drought and salinity stress

Physiological responses of bluestem (Andropogon virginicus), reed canarygrass (Phalaris arundinacea), switchgrass (Panicum virgatum) under drought and salinity were studied at their vegetative growth stage. The experiments were conducted in pots in greenhouse using orthogonal matrix design at three factors (plant, soil water content and saline concentration) with three levels. The results showed that the contents of proline and soluble sugar, the activities of peroxidase (POD) and catalase (CAT) in leaves only increased or decreased first and then increased along with the reduction of the soil water content. However, the CAT activity of switchgrass firstly increased and then decreased and reached maximum at 7% water concentration. The contents of proline and soluble sugar, POD activity in leaves only increased or firstly decreased and then increased along with the increment of saline concentration, whereas in bluestem increased first and then decreased, reached maximum at 2‰ salt concentration. The CAT activities in bluestem, reed canarygrass and switchgrass firstly increased and then decreased, and reached maximum at saline concentrations of 2‰, 4‰ and 6‰, respectively. Bluestem and reed canarygrass had the strong adaptive capacity under drought stress, but were sensitive to salt stress. Switchgrass has strong adaptability under drought and salinity stress.