Storage duration, light, temperature, and salinity exposure influence germination of the glycophyte Rhanterium epapposum

Abstract

Regeneration of native species is the first priority for biodiversity conservation and restoration. To this end, it is key to have seeds properly conserved in seed banks and knowledge of seed longevity and (or) dormancy alleviation at different storage time intervals. In addition, understanding the germination response of the stored seeds to environmental conditions improves the efficiency of restoration and rehabilitation projects. We investigated the influence of storage duration (1–5 years), light (0 or 12 h of illumination), thermoperiod (night/day temperatures of 15/20 and 20/25 °C), and salinity (0, 100, 200. and 400 mmol/L of NaCl) on seed germination of Rhanterium epapposum, a glycophytic species from the Arabian Peninsula. Seeds maintained viability after five years of storage indoors at room temperature. Three years of storage alleviated seed dormancy. Exposure to 12 h light per day and thermoperiods of 15/20 °C enhanced seed germination. The seeds were glycophytic; after-ripened seeds exposed to salinity exhibited reduced rates of germination that did not recover after the salinity was alleviated.