Improving seed germination and seedling growth of Lepidium sativum with different priming methods under arsenic stress

This study was carried out to determine the effects of seven kinds of priming, gibberellic acid (GA), salicylic acid (SA), citric acid (CA), sodium chloride (NaCl), potassium chloride (KCl), zinc (Zn) and iron (Fe) on seed germination and seedling emergence of garden cress (Lepidium sativum) under arsenic stress. Results revealed that germination percentage (GP), seed vigor index (SVI), radicle length (RL), plumule length (PL) and tolerance index (TI) were significantly decreased when arsenic stress was augmented from 0 to 100 mg L−1. Nevertheless, primed seeds (hormo, nutri and halo-priming) increased seed germination and seedling emergence and tolerance index of L. sativum. Phytotoxicity was also reduced by priming practices. Meanwhile, priming with gibberellic acid (GA) had the most positive effects on measured traits. Generally, the order of the effect of priming treatments tested decreases by the following order: GA > CA > KCl > Fe > Zn > SA > NaCl. The result of this study is coherent with the hypothesis that under heavy metal stress, priming can develop seed germination performance and seedling emergence.