Improving the growth, yield and iron concentration of strawberry using sodium hydrosulfide (NaHS) under soilless culture

Abstract

Required iron (Fe) for the growing plants in soilless culture could be obtained from various Fe sources such as chelates and ferrous sulfate (FeSO4). Despite the low cost of FeSO4, this source is rarely used due to the low Fe solubility at a high pH. Here, the role of sodium hydrosulfide (NaHS) in improving growth and iron availability in strawberry (Fragaria × ananassa cv. Paros) grown in FeSO4 culture solution was reported. The plants were grown hydroponically with two Fe sources, Fe-EDTA and FeSO4 along with three levels (0, 0.2, and 0.5 mM (of H2S donor, NaHS. The results showed that vegetative growth and yield of strawberry under FeSO4 source were lower than Fe-EDTA treated plants. Using NaHS significantly improved vegetative and reproductive growth, yield, chlorophyll SPAD value, maximum efficiency of photosystem II (Fv/Fm), and Fe availability of strawberries under FeSO4 source. Exogenously applied NaHS reduced the hydrogen peroxide (H2O2) and malondialdehyde (MDA) production and electrolyte leakage (EL) in the leaves by enhancing enzymatic antioxidant activity (ascorbate peroxidase, superoxide dismutase, and catalase) in FeSO4 source. Moreover, NaHS affected fruit yield under Fe-EDTA utilization and showed a significant increase in yield amount (by 29.75%) compared to control. In general, there were no significant differences between the two levels of NaHS, 0.2 and 0.5 mM. Our results indicated that H2S affects the maintenance of cell membrane integrity and subsequently iron availability by strengthening the enzymatic antioxidant system and reducing oxidative stress.