Comparison of photosystem II yield in 240 native wheat genotypes of Iran using chlorophyll fluorescence parameters under salinity stress

One of the important abiotic stresses in the arid and semi-arid world, including Iran, is soil and water salinity that reduces crop yield. Determination of damage amount of salinity stress to crops such as wheat is also essential. Since chlorophyll fluorescence analysis has become an important tool in fundamental and applied research in the field of plant physiology and agronomy, this experiment was conducted to investigate the effect of salinity on chlorophyll fluorescence of 240 wheat genotypes at three levels of salinity (0, 9, 12 dS.m-1) in greenhouse conditions. After 21 days of salinity stress, chlorophyll fluorescence parameters and related transients (Fo, Fv, Fm, Fv/Fm, Vj, PI, Fv/Fo, and ABS/RC) and the photosynthetic pigments were measured. All photosynthetic pigments decreased after salinity stress, and this decrease was significant in susceptible genotypes. Salinity also significantly reduced the quantum yield of photosystem II (Ø PSII) and the maximum quantum yield of photosystem II (Fv/Fm) and significantly increased the ABS/RC, Fo, and Vj parameters in susceptible genotypes.