荒漠植物雾冰藜和沙米叶片对凝结水响应的模拟实验

通过模拟凝结水实验，研究了荒漠被毛植物雾冰藜和无毛植物沙米的叶片是否吸收凝结水。试验设计无模拟凝结水、偶尔发生凝结水以及频繁发生凝结水3个处理，每个处理又分干旱条件和人工浇水两组控制试验，研究了模拟凝结水对雾冰藜和沙米枝条相对含水量、水势、净光合速率、气孔导度、基径、地上和地下生物量的影响。结果表明,对于被毛植物雾冰藜而言，模拟凝结水显著提高了人工浇水和干旱条件下的气孔导度和地上生物量，仅提高了干旱条件下植株的水势、相对含水量、净光合速率以及地下生物量；而对于植株的基径有较小的效应。对于无毛植物沙米而言，模拟凝结水对两种水分条件下的枝条相对含水量、水势、净光合速率、气孔导度、基径、地上和地下生物量影响不大。因此，有毛植物雾冰藜的叶片可以吸收凝结水，并且其植株的光合作用、水分关系以及其生长都会对凝结水的发生产生响应，而无毛植物沙米叶片不吸收凝结水。

Experimental Study of Effects of Artificial Dew on Bassia dasyphylla and Agriophyllum squarrosum

The effects of foliar absorption of dew by hairy leaves of Bassia dasyphylla and nonhairy leaves of Agriophyllum squarrosum on shoot water potential, relative water content, net photosynthesis, stomatal conductance, basal diameter, aboveground dry mass and root dry mass were investigated. Bassia dasyphylla and Agriophyllum squarrosum seedlings were subjected to contrasting water regimes (normal condition and deficient water) and three kinds of artificial dew simulation (none, once per week and three times per week). The results are as follows. Artificial dew significantly increased shoot stomatal conductance and aboveground dry mass of Bassia dasyphylla seedlings subjected to water deficient and normal condition. Obvious responses in shoot water potential, relative water content, net photosynthesis, and root dry mass were observed for Bassia dasyphylla seedlings subjected to water deficient. The little effects of dew on basal diameter were observed. No obvious effects were found in shoot water potential, net photosynthesis, stomatal conductance, basal diameter, aboveground dry mass and root dry mass of nonhairy leaves of Agriophyllum squarrosum seedlings subjected to water deficient and normal condition. Obviously, we can draw a conclusion that hairy leafs of Bassia dasyphylla may improve leaf water status by dew absorption, while nonhairy leaves of Agriophyllum squarrosum can not absorb dew.