Effect Of Nacl On The Photosynthesis Parameters In Salix Matsudana Koidz

In order to evaluate the effects of NaCl stress on seedlings of Salix matsudana Koidz, the effects of different NaCl concentrations (0, 0.1%, 0.2%, 0.4%) on one-month-old S. matsudana seedlings grown in an environment-controlled chamber for 28 days was examined. Responses of S. matsudana were monitored in relation to physiological parameters, leaf fall ratio, relative water content (RWC), photosynthetic gas exchange characteristics and chlorophyll fluorescence parameters and chlorophyll concentration. The plants did not show any effect on survival and grew normally without toxic symptoms under 0.1% NaCl, and had different numbers of yellow leaves at the base of the seedlings and new leaves dried under 0.2% and 0.4% NaCl for 28 days. Plant growth, biomass and RWC decreased linearly with an increase in salinity and duration. After the experiment, over a half of the leaves that were treated with 0.4% NaCl had fallen. The chlorophyll contents in the leaves decreased with increasing of NaCl salinity. Leaf photosynthetic gas exchange parameters (net photosynthetic rate, transpiration rate, intercellular CO2 concentration and stomatal conductance) showed varying correlations and an overall decrease in these parameters under NaCl treatment period compared with the control. The decrease tendency in photochemical efficiency of PSII (F-v'/F-m'), actual photochemical efficiency of PSII (Phi PSII), electronic transfer rate (ETR) and photochemical quenching (qP) were observed, whereas qN had an increasing tendency.