Chlorophyll fluorescence as criterion for the diagnosis salt stress in wheat (triticum aestivum) plants

To investigate effect of salt stress on Chlorophyll fluorescence four cultivars (fong,star,chamran and kharchia) of wheat (Triticum aestivum) plants subjected to salinity levels (control,8,12 and 16 dsm-1) from one week after emergence to the end of stem elongation under greenhouse condition. results showed that quantum yield of photosystem II from light adopted leaves (ΦPSII), Photochemical quenching (qP),quantum yield of dark adopted leaves (fv/fm) and non photochemical quenching (NPq) were affected by salt stress. Salinity levels affected photosynthetic rate. Star and fong cultivars showed minimum and maximum levels of photosynthetic rate in respectively. Minimum photosynthetic rate differences between levels of salinity were shown in Kharchia. Shoot dry matter of all cultivars decreased by increasing salinity levels. Results showed that non photochemical quenching by salinity levels attribute to the decreases in shoot dry matter.