Abstract:

In this study， the effects of the lead （Pb） halide perovskite on the growth of Elymus nutans， a high-quality forage， were determined. Seedlings of E. nutans were treated with perovskite at six concentrations （0， 36， 72， 130， 170， and 260 mg·kg^-1 Pb²⁺）， and their ability to accumulate and tolerate Pb was determined. The main results were as follows： 1）Pb did not significantly affect the emergence ratio of E. nutans seedlings， but increasing concentrations of Pb resulted in significantly decreased emergence rate and a shorter duration of seedling emergence. 2）Seedling height was significantly inhibited by Pb stress， while single seedling biomass showed a concentration effect， in that it was not affected by Pb²⁺ at concentrations below 72 mg·kg^-1， but was inhibited by Pb at concentrations above 72 mg·kg^-1. Seed germination was completely inhibited by Pb at 260 mg·kg^-1. 3）The Pb accumulation ability of E. nutans seedlings decreased significantly compared with the control group， and the Pb tolerance range of seedlings was 68.42-205.94 mg·kg^-1.^{4）The structure equation model indicated that decreased soil pH and increased soil nitrate nitrogen contents resulting from perovskite directly affected the seedling growth of E. nutans， thus affecting its ability to accumulate and tolerate Pb. In conclusion， the soil pH and nitrate nitrogen content are the key factors affecting the seedling growth of E. nutans， and increasing the soil pH is a feasible strategy to enhance the Pb tolerance of E. nutans in the face of potential leaks of the lead halide perovskite.}

Key words: Pb stress, Elymus nutans, seedling growth, Pb accumulation ability, tolerance range