果树叶面滞尘对叶片气体交换参数的影响——以叶城县核桃和苹果为例

Effects of Dust Retention on Leaf Surface of Main Fruits in Yecheng County on Leaf Gas Exchange Parameters

本研究选用2种本土经济果树测定叶片在滞尘和未滞尘2种处理对气体交换参数变化特征及水分利用特性的影响。采用LI-6400便携式光合作用系统可以测量出树种叶片的气体交换参数,得出水分利用率日变化特性及其相关性分析。滞尘对苹果叶片气体交换参数中除叶片蒸腾速率外其余气体交换参数的影响比起核桃较低;核桃未清洗和清洗叶片净光合速率(Pn)与水分利用率(WUE)呈极显著相关(P<0.01),核桃未清洗和清洗叶片净光合速率与未清洗叶片气孔导度(Gs)负相关,清洗叶片气孔导度(Gs)呈显著相关(P<0.05)。苹果清洗和未清洗叶片净光合速率(Pn)与蒸腾速率(Tr)、气孔导度(Gs)呈极显著相关(P<0.01);未清洗叶片净光合速率(Pn)水分利用率(WUE)呈正相关,清洗叶片净光合速率(Pn)呈显著相关(P<0.05)。综合分析,苹果在叶城县降尘条件下光合特性好,水分利用率佳,可作为当地乡土经济林果树当中优先选用树种,但核桃树滞尘能力好,滞尘均有重要贡献,可作为当地乡土园林绿化和减小颗粒物污染树木当中优先选用树种。

In this study,2 species of local economic fruit trees were selected to determine the effects of two treatments on the characteristics of gas exchange parameters and water use characteristics when the leaves were dust-retained and not dust-retained.The LI-6400 portable photosynthesis system was used to measure the gas exchange parameters of the leaves of tree species,and obtain the daily change characteristics of water use efficiency and its correlation analysis.The effect of dust retention on the gas exchange parameters of apple leaves except for leaf transpiration rate was lower than that of walnuts;The net photosynthetic rate(Pn)of unwashed and washed walnut leaves was extremely significantly correlated with water use efficiency(WUE)(P<0.01),and negatively correlated with the stomatal conductance(Gs)of unwashed leaves.The stomatal conductance(Gs)of cleaned leaves was significantly correlated(P<0.05).The net photosynthetic rate(Pn)of cleaned and uncleaned apple leaves was extremely significantly correlated with transpiration rate(Tr)and stomatal conductance(Gs)(P<0.01);net photosynthetic rate(Pn)of uncleaned leaves and water use efficiency(WUE)was positively correlated,and the net photosynthetic rate(Pn)of cleaned leaves was significantly correlated(P<0.05);According to comprehensive analysis,apples showed good photosynthetic characteristics and good water use efficiency under the conditions of dust fall in Yecheng County,which could be used as the preferred tree species among fruit trees in local economic forests.However,walnut trees had good dust retention capabilities and demonstrated important contributions to dust retention,so they might be used as local landscaping natives and reducing particulate pollution tree species.