叶尔羌河流域胡杨不同叶形水分利用效率

Water use efficiency of different leaf shapes of Populus euphratica in Yarkant River basin

文中以叶尔羌河流域荒漠河岸林典型建群种植物-胡杨(Populus euphratica)为研究对象,运用替代指标法,测定胡杨不同叶形(披针形、卵圆形和锯齿卵圆形)的比叶重、含水量、灰分、叶绿素、N和K等生理指标及土壤含水量,表征胡杨不同叶形的水分利用效率(WUE)。结果表明:运用比叶重、含水量、灰分、叶绿素、N五个指标,分析胡杨不同叶形水分利用效率为锯齿卵圆形>卵圆形>披针形,差异显著(P<0.05);K分析表明胡杨不同叶形水分利用效率为卵圆形>锯齿卵圆形>披针形,差异显著(P<0.05);相关文献中稳定碳同位素技术分析胡杨不同叶形水分利用效率为锯齿卵圆形>卵圆形>披针形。从上述分析结果可以看出,胡杨不同叶形的比叶重、叶片含水量、灰分、叶绿素、N均与稳定碳同位素技术分析结果一致,可以作为替代指标分析植物水分利用效率;叶片K与稳定碳同位素技术分析基本一致,与其他指标相比替代性较弱。

Populus euphratica Oliv. is an important tree species for desert riparian forest. In this research we studied the water use efficiency of different leaf shapes （lanceolate leaves ,ovate leaves and dentate broad - ovate leaves） of P. euphratica in Yarkant River basin with substitution index method. The physiological factors of different leaf shapes of P. euphratica included specific leaf weight, ash content,leaf water content, chlorophyll, K and N, and the physical properties of soil, such as water content. These physiological factors were used as the substitution indexes to analyze the water use efficiency. The results indicate that water use deficiencies of different leaf shapes of the plant was ： dentate broad - ovate leaves 〉 ovate leaves 〉 lanceolate leaves by analyzing the five indexes of specific leaf weight, ash content, leaf water content, chlorophyll, and N, and the differences were significant （ p 〈 0.05 ）. While the WUE was ： ovate leaves 〉 dentate broad - ovate leaves 〉 lanceolate by analyzing K, and the differences were significant （ p 〈 0.05 ）. It was reported that water use efficiency of different leaf shapes of Populus euphratica was dentate broad -ovate leaves 〉 ovate leaves 〉 lanceolate leaves through sta-ble carbon isotope technique. Therefore, the analysis results of the substitution index were basically consistent with stable carbon isotope technique. So, specific leaf weight, ash content, leaf water content, chlorophyll, and N could be used to analyze the plant water use efficiency, but K is relatively weak.