Response of Transpira tion and Na+ Intake of Seedlingto Cutting Root and NaCl Trea tments

There were no report on whether cutting root influence salinity intake in afforestation in saline-alkali soils.To further examine the response of transp iration and Na+ intake of seedling to cutting root and NaCl treatment, itwastested to leaf damage rate, transp iration rate and Na+ content in the root, branches and leaves, by cutting absorption root of the seedling of Cyclobalanopsis m y rsinaefolia and Osm anthus fragrans var. auran tiacus under the condition of 150 mmol NaCl treatment. The results showed: (1) Cutting root treatments of both C. m yrsinaefolia and O.fragrans var. auran tiacus resulted in the increase ofNa+ content and its content ratio, which leaded to the increasement of leaf damage rate. (2) If NaCl treatmentswere immediately done after cutting root, itwas significant to increase Na+ up take, caused serious salinity p roblems, and largest range of decrease of transp iration rate. In contrast,if NaCl treatmentswere done on 3 days after cutting root, Na+ intake and salinity p roblems were obviously inhibi2ted. (3) Na+ up take increased with the increase of transp iration rate in C. m y rsinaefolia and O. frag rans, and therewas a significant positive correlation ( r = 0. 613**, n = 18) between Na+ up take and transp iration rate for O. fragrans. All these suggested that it was not feasible for afforestation in saline2alkali soils to cutting root of seedling,however, if itmust be cut, it was necessary to heeling-in for a few days in the garden to p revent salinity p roblem from the rap id up take of salinity.