【摘要】 采用盆栽控水方法,在不同土壤相对含水量条件下,分别对梨属矮化砧K22和OH×F51以及乔砧杜梨叶片的光合速率、蒸腾速率等进行了测定。结果显示,在砧木旺盛生长期,随着土壤相对含水量的降低,3种梨属砧木的光合速率、蒸腾速率和气孔导度均呈下降趋势,但梨属矮化砧K22和OH×F51的光合速率明显高于乔砧杜梨,且二者的水分利用率也高于乔砧杜梨,并呈先升高后降低的趋势,乔砧杜梨的水分利用率则随土壤相对含水量的减少而一直降低;3种梨属砧木的胞间二氧化碳浓度随土壤相对含水量的减少呈先降低后升高的趋势,相比乔砧杜梨,梨属矮化砧在更低的土壤相对含水量时,胞间二氧化碳浓度才开始升高。说明梨属矮化砧K22,OH×F51能够维持较高的光合生产能力,并且气孔导度大幅降低,抑制蒸腾速率,有利于提高水分利用效率。更多还原

【Abstract】 The photosynthesis was studied on pyrus dwarf rootstocks K22, OH×F51and vigorous stock Pyrus betulaefolia Bunge under different soil relative water contents by potted plants. The results showed that during the vigorous growth period, as the soil relative water contents decreasing, the photosynthetic rate, transpiration rate and stomatal conductance of three pear rootstocks gradually reduced,but the photosynthetic rate of K22 and OH×F51was obviously higher than that of vigorous stock Pyrus betulaefolia Bunge. And the water use efficiency of K22 and OH×F51was higher than that of vigorous stock Pyrus betulaefolia Bunge, moreover K22 and OH×F51increased first and then decreased, but vigorous stock Pyrus betulaefolia Bunge decreased. Intercellular CO2 of three kinds of pyrus rootstocks decreased first and then increased, and pyrus dwarf rootstocks cause intercellular CO2 began to rise in lower water content than vigorous stock Pyrus betulaefolia Bunge. The result explained that the K22, OH×F51of pyrus dwarf rootstocks could keep higher photosynthetic production capacity and considerably decreased stomatal conductance and transpiration rate, which was favorable to increasing water use efficiency of pyrus dwarf rootstocks.更多还原