植物叶片润湿性特征的初步研究

Primary Research on the Wettability of Leaves of Selected Plants in Shaanxi Province

植物叶片的润湿性表现了叶片对水的亲和能力，叶片上润湿的一层水膜对植物的光合作用、叶片截流降水有重要的影响。测定了陕西省境内34种植物叶片对水的接触角，初步探讨了叶片润湿性的一些特征。所研究植物叶片正面的接触角为0°～140°，平均85．4°。接触角大于95°不润湿的植物占到测定总数的31．4％；小于85°润湿植物中占到51％以上；而介于润湿与不润湿之间的物种占17．1％。叶片的正面和背面的润湿性具有一定水平的差异。叶面角质与腊质的比例对润湿性有重要的影响。叶片上附属物的多少也会对润湿性产生影响，附属物愈多，润湿性愈差；人为去除附属物可以极大地增加叶片的润湿性能。植物叶片上的气孔和叶脉通过影响叶片的粗糙程度来影响叶片的湿润性。

The wettability of plant leaves, reflects the affinity about the water to leaves, and the water membrane on a leaf has the key influences on photosynthesis and rainfall interception. Contact angles of water were measured for 35 species plants in Shaanxi Province, and the wettability of leaves was researched prima- rily. Contact angles of adaxial leaves were 0°-140° , with an averaged 85.4° . According to contact angle, the plant species that are non-wettability or repellency with the value more than 95° was 31.4° of total measurements; the species with contact value less than 85° was more than 51% of the total; and there were 17.1 % plant with contact angle of 85°-95° , which means that the vcettability of the leaves lies between wetness and repellency. For a plant leaf, the wettability on adaxial and reverse leaves was somewhat different. The ratio of cuticle to wax of plant leaf had significance to leaf wettability. The degree of subsidiary hair on a leaf had influence to wettability and the wettability of the leaf became worse along with the subsidiary increased. If the subsidiary hair was rejected, the wettability of leaf would become better. The stoma and vein on the leaf affected the wettability through increasing the roughness of plant leaf.