[Physiological response of two divergent Leymus chinensis types to drought stress in the Songnen Plain].

The physiological response of two divergent Leymus chinensis types (grey-green type and yellow-green type) to drought stress was studied by pot experiment. At seedling stage, some physiological indexes of the plants and leaves were measured by taking the divergent types under stress of polyethylene glycol (PEG). Quantitative analyses showed that under drought stress, the electrolyte leakage rate, proline content, water content, fresh weight, and SO(4)2- and NO3- contents of two divergent types varied significantly. According to the simulating results by equation y = a + bx, the b values of electrolyte leakage rate and chlorophyll content were higher in grey-green type than in yellow-green type, and the b value of water content of grey-green type was lower than that of yellow-green type. The proline content of grey-green type was higher than that of yellow-green type. Factor analyses showed that proline was the most important factor of physiological response to drought stress of the two types. The two types of L. chinensis had certain capabilities of drought resistance, but the capability of grey-green type was greater than that of yellow-green type. Therefore, the physiological characteristics of drought resistance were significantly differentiated.