松嫩平原两种趋异类型羊草对干旱胁迫的生理响应

采用盆栽实验，对灰绿和黄绿两种趋异类型羊草（Leymus chinensis(Trin.)Tzvel.）幼苗期用聚乙二醇（PEG）胁迫进行干旱生理指标测定，结果表明，在干旱胁迫下，灰绿型羊草和黄绿型羊草的电解质外渗率、脯氨酸、植株含水率、植株鲜重、SO4^2-、NO3^-之间均有显著或极显著差异，灰绿型羊草叶片电解质外渗率和叶绿素含量的b值均大于黄绿型羊草，而植株含水率的b值则小于黄绿型羊草，灰绿型羊草脯氨酸含量均大于黄绿型羊草，因子分析表明，脯氨酸是两种趋异类型羊草干旱胁迫生理反应的主要因子，两种趋异类型羊草在生理响应中均体现出耐旱能力，但灰绿型羊草的耐旱能力比黄绿型更强，两种趋异类型羊草在耐旱生理上有明显分化。

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 NO 3 - contents of two divergent types varied significantly. According to the simulating results by equation y =a+b x , 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.