松嫩平原两个生态型羊草水分生理特性对CO2倍增和干旱胁迫的响应

Response of water physiology characteristics for two ecotype Leymus chinensis to CO2 doubling and drought stress in the Songnen Plain

采用盆栽法对灰绿色和黄绿色生态型羊草在干旱和CO2倍增交互胁迫条件下的水分生理响应进行了研究.结果表明:在对照和700μmol/mol CO2胁迫条件下,灰绿型和黄绿型羊草的蒸腾速率、水分利用效率、气孔导度与干旱胁迫胁强之间的关系呈直线变化,多数达到显著或极显著相关.灰绿型羊草的水分利用效率随干旱胁迫的增加速率比黄绿型羊草高,黄绿型羊草气孔导度对干旱胁迫的下降速率高于灰绿型.两个生态型羊草的蒸腾速率、水分利用效率、气孔导度之间具有显著差异.灰绿型和黄绿型羊草的1龄和2龄植株在700μmol/mol CO2胁迫时的蒸腾速率、水分利用效率、均高于对照,气孔导度低于350μmol/mol CO2胁迫时.t检验结果表明,在350,700μmol/mol CO2胁迫条件下,两个生态型的1龄、2龄植株间的蒸腾速率、水分利用效率、气孔导度差异显著.由此表明干旱条件对灰绿型和黄绿型羊草的1龄、2龄植株的蒸腾速率、水分利用效率和气孔导度有显著影响,两个生态型的1龄、2龄植株之间具有显著差异,灰绿型羊草水分利用能力高于黄绿型羊草.CO 2倍增胁迫对干旱条件下两个生态型羊草植株蒸腾速率和水分利用效率的降低有一定的缓解作用.

When the concentration of CO2 was 350 and 700μmol/mol,the relationship between transpiration rate,water use efficiency,stomatal conductance and drought stress was linear for grey-green ecotype L.chinensis and yellow-green ecotype L.chinensis.Most of them are significant or extremely significant.The increasing rate of water use efficiency of grey green L.chinensis is higher than that of yellow green L.chinensis.The decrease rate of the stomatal conductance of the yellow green L.chinensis was higher than that of the grey green type.There were significant differences in transpiration rate,water use efficiency and stomatal conductance between two ecotypes of L.chinensis.For one and two years old plants of two ecotypes of L.chinensis,the transpiration rate and water use efficiency in the concentration of 700μmol/mol were higher than that in the concentration of 350μmol/mol,but the stomatal conductance was lower than that in 350μmol/mol CO2.The t test results showed there were significant differences in transpiration rate,water use efficiency and stomatal conductance among the two ecotypes of one and two years old when the concentration of CO2 was 350 and 700μmol/mol.The drought conditions had significant effects on the transpiration rate,water use efficiency and stomatal conductance of the one and two years old plants of grey-green and yellow-green ecotypes L.chinensis.There were significant differences between two ecotypes of one and two years old and the water use ability of grey green L.chinensis is higher than that of yellow green L.chinensis.In addition,high concentration of CO2 could alleviate the transpiration rate and water use efficiency of two ecotypes of L.chinensis.