土壤水分状况对浙江楠幼苗的影响

Effects of Soil Moisture Status on the Phoebe chekiangensis Seedings

以完全随机试验设计对不同土壤水分条件下浙江楠幼苗生长及某些生理特性进行了研究。结果表明:随着土壤含水率的增加,单叶面积、单叶鲜重、单叶干重、比叶面积逐渐增大,但叶片厚度、肉质度减小;叶片的叶绿素含量对土壤水分状况较为敏感,5种水分处理下苗木叶片的叶绿素含量有较大的差异。土壤干旱和水涝均影响叶绿素a和叶绿素b的合成。在轻度干旱时,苗木的含水率、自然饱和亏缺和水势的变化不大,而在重度干旱时,苗木的含水率降低,自然饱和亏缺增大,水势降低,叶片的光合能力降低,苗木生长缓慢,生物量下降,说明土壤水分状况对净光合作用速率有重要影响。

The growth and certain physiological characters of Phoebe chekiangensis seedlings under various soil moisture stress were studied. With the increasing of soil moisture, the individual leaf area,the leaf dried mass per seedling,the leaf fresh mass per seedling and leaf area per leaf dried mass（LAM）increased, but the leaf thickness and succulence degree decreared;The content of leaf chlorophyll was sensitive to soil moisture,under 5 kinds of different soil moisture status and the content of leaf chlorophyll was distinct. The drought and inundation were much destructive to the synthesis of both chlorophyll a and chlorophyll b. Under the light drought condition, the change of the containing water content, water saturation deficit and water potential were not evident, but under the serious drought condition, the containing water content and water potential fell, the water saturation deficit increased; the soil moisture status affected the net photosynthetic rate（Pn）, serious drought would result in the smaller Pn, and seedlings＇growth slowed down.