LAUSR

Abstract Plant stress caused by alkalinity in irrigation water can significantly limit the growth and development of plants. Emerging evidence suggests that hydrogen sulfide (H2S), as a versatile signal molecule, can ameliorate stress-induced adverse effects. The objective of this study was to determine the effects of sodium hydrosulfide (NaHS) application on growth, fruit yield and biochemical responses of strawberry plants exposed to alkalinity stress under greenhouse conditions. Strawberry plants were grown hydroponically under three levels (0, 15 and 30 mM) of alkalinity stress (induced using sodium bicarbonate and sodium carbonate) along with three levels of foliar application (0, 0.2 and 0.5 mM) of the H2S donor, NaHS. The results showed that compared to the control conditions, alkalinity stress reduced plant biomass, fruit yield, maximum quantum efficiency of photosystem II (Fv/Fm) and chlorophyll SPAD value. Oxidative stress was induced, which was measured, as accumulation of reactive oxygen species (ROS). On the other hand, when alkalinity stress was mitigated with the application of NaHS, the recovery of photosynthetic activity, a decrease in ROS and an improvement in antioxidative defense system were observed. Overall, NaHS treatments had the best results on lower level (15 mM) of alkalinity stress compared to the 30 mM alkalinity stress. These findings indicate possible role for H2S for improving strawberry plant growth and yield under non-stress conditions and moderate alkalinity stress.