Effect of drought stress and glycine betaine as foliar application on photosynthesis parameters of chickpea

Drought is one of the most important factors limiting crop growth and in most phases of plant growth effect is harmful and destructive. Therefore use of practice to reduce its adverse effect is very important. It seems that, through exogenous application of glycine betaine, plant resistance to drought stress can be increased. In order to investigate the effect of drought stress and glycine betaine foliar spraying on photosynthetic parameters of chickpea, a factorial experiment was conducted in a completely randomized block design with three replications in a research greenhouse of the Faculty of Agriculture of Lorestan University in 2017. Drought stress in four levels (control, 75, 50 and 25 of field capacity) and foliar spraying application of glycine betaine in three levels (0, 25 and 50 mM) were applied. The results showed that drought stress significant at 1% level of probability decreased photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, photosynthetic water use efficiency and carboxylation efficiency, but glycine betaine notably improved them. Glycine betaine application enhanced the photosynthesis in water-deficit experiencing plants, mostly due to a greater stomatal conductance and carboxylation efficiency of CO2 assimilation. It could be concluded that spraying glycine betaine (25 mM) improve photosynthetic parameters in drought conditions and induces more water stress tolerance in chickpea.