Iris × germanica L. and Nephrolepis exaltata (L.) Schott, two novel strontium hyperaccumulators

We examined the uptake and the effects of strontium (Sr) and vanadium (V) on the growth of hydroponically cultivated species Nephrolepis exaltata (L.) Schott (NE) and Iris × germanica L. (IG). Each species was cultivated in deep water culture tanks in solutions containing 0–80 mg/L NH₄VO₃ and subsequently 50–200 mg/L Sr(NO₃)₂ for two weeks. The accumulated ions in the plant parts were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that across tested concentrations, neither strontium nor vanadium exerted any sizable effect on the growth of the two species. Both species efficiently accumulated Sr, with translocation factors (TF) consistently above 1 (approximately 1.2–2.2) and bioconcentration factors (BCF) ranging from approximately 6 to 9, meeting the criteria for classification as Sr hyperaccumulators. Total metal uptake reached values on the order of 10³ mg/kg in both species at the highest concentrations tested. These results suggest that both NE and IG hold significant promise for Sr phytoremediation applications, demonstrating high tolerance to V and substantial root retention capacity, suggesting their potential utility in the phytostabilization of V-contaminated soils.