Seed priming improves germination of Arabis alpina under thermo-inhibiting conditions

Seed enhancement techniques are widely used to improve germination of crop species, but the usefulness of these techniques has been poorly studied in wild species. Improved seed germination and seed and seedling stress resistance would be beneficial for large scale restoration projects. Here we investigate priming as a technique to enhance the germination of four seed batches of Arabis alpina under germination-inhibiting conditions, i.e. high temperature and darkness. Response to the priming treatments (soaking in water or in solutions of gibberellic acid, karrikinolide, nitrate and sodium hypochlorite) varied among seed batches. Final germination and the germination rate of two of the batches were stimulated under inhibitory conditions upon priming with gibberellic acid and karrikinolide solutions, while no effects were observed in two other seed batches. We conclude that priming can enhance germination of Arabis alpina seeds. However, seed batches from different sources displayed wide variation in responsiveness to the treatments.