Effect of Calcium Chloride(CaCl_2) on Chlorophyll Fluorescence Image and Photosynthetic Apparatus in the Leaves of Prunus sargentii

摘要

There is a little information on the effect of calcium cloride (CaCl_2) which is used as deicing salt in Korea on the physiological responses of the street trees. Prunus sargentii is one of the most widespread tree species of street vegetation in Korea. In this study, the effect of CaCl_2 on photosynthetic apparatus such as chlorophyll fluorescence image and light response curve of P. sargentii in relation to their leaf and root collar growth responses were investigated. To study the effect of CaCl_2treatment in the early spring, we irrigated twice in rhizosphere of P. sargentii (3-year-old) planted plastic pots with solution of 0.5%, 1.0%, 3.0% CaCl_2 concentration before leaf expansion. Results after treatments, total chlorophyll contents and thechlorophyll a/b, photosynthetic rate, quantum yield, dark respiration decreased with increasing CaCl_2 concentration. On the contrary, light compensation point increased with increasing CaCl_2 concentration. Through the linear regressions of correlationof photosynthetic rate with photosynthetic parameters (quantum yield, dark respiration and light compensation point), we found a significant relationship (p<0.05) between photosynthetic rate and quantum yield and light compensation point except dark respiration. Calcium cloride (CaCl_2 induced inhibition of photochemical efficiency (F_v/F_M) and non-photochemical quenching (NPQ) were found in treatments of CaCl_2 and these reduction rates between control and CaCl_2 treatments were drastically showedat 80 days. We suggest that physiological activities are limited from treatment of CaCl_2 . These reductions of photosynthetic apparatus ability caused eventually the reduction of leaf and diameter at root collar growth.