Augé Robert M, Green Craig D, Stodola Ann J W, Saxton Arnold M, Olinick Joshua B, Evans Richard M
1 Institute of Agriculture, Tennessee Agricultural Experiment Station, University of Tennessee, P.O. Box 1071, Knoxville, TN 37901-1071 USA.
New Phytol. 2000 Mar;145(3):483-500. doi: 10.1046/j.1469-8137.2000.00604.x.
Recent research in whole-plant stomatal physiology, conducted largely with potted plants in controlled environments, suggests that stomatal conductance (g ) might be more closely linked to plant chemical variables than to hydraulic variables. To test this in a field situation, seasonal g was examined in relation to a number of plant and environmental variables in 11 temperate, deciduous forest tree species. Stomatal conductance was generally better correlated with environmental variables (air temperature, vapor pressure deficit, PPFD) than with plant variables, and slightly better correlated with plant hydraulic variables (shoot water and osmotic potentials) than with plant chemical variables (xylem sap ABA concentration, xylem sap pH). We examined a model, developed previously for maize, which describes regulation of g by xylem sap ABA concentration with leaf water status acting to modify stomatal sensitivity to the ABA signal. This model explained slightly more variation in seasonal g in the forest trees than did single plant variables but not more variation than most single environmental variables. Response surface models, especially those incorporating environmental variables, were more consistently successful at explaining g across species.
近期关于整株植物气孔生理学的研究主要是在可控环境下对盆栽植物进行的，研究表明气孔导度（g）可能与植物化学变量的联系比与水力变量的联系更为紧密。为了在田间条件下对此进行验证，我们研究了11种温带落叶林树种的季节性气孔导度与多种植物和环境变量之间的关系。气孔导度通常与环境变量（气温、水汽压亏缺、光合有效辐射）的相关性比与植物变量的相关性更好，并且与植物水力变量（茎水势和渗透势）的相关性略好于与植物化学变量（木质部汁液脱落酸浓度、木质部汁液pH值）的相关性。我们检验了一个先前为玉米建立的模型，该模型描述了木质部汁液脱落酸浓度对气孔导度的调节作用，同时叶片水分状况会改变气孔对脱落酸信号的敏感性。该模型对森林树木季节性气孔导度变化的解释略多于单个植物变量，但并不比大多数单个环境变量解释的变化更多。响应面模型，尤其是那些包含环境变量的模型，在解释不同物种的气孔导度方面更为成功。
