Dormienza e alotolleranza in due specie spontanee di Hordeum (H. murinum L. e H. marinum Huds.)

Abstract

Dormancy and salt-tolerance in two spontaneous species of Hordeum. — Dormancy behaviour and germination capacity in salt-solutions of Hordeum murinum L. and Hordeum marinum Huds. seeds have been studied. Seeds (caryopses) have been sown in Petri dishes on filter paper soaked with deionized water (control) or with NaCl solutions at concentrations: 3.2 - 6.5 - 13.0 - 26.0%. Germination was tested during after-ripening, 20, 40, 60, 100, 160, 260 and 365 days from harvest (fully ripe seeds). The two species of Hordeum are spontaneous and characterized by peculiar ecological features. The present results have shown that, during the first year from harvest, Hordeum murinum and H. marinum have different length and strength of dormancy (longer and stronger in H. marinum than in H. murinum). Germination capacity and energy of the two species — during after-ripening stage — when seeds are sown in salt-solutions differ strongly and seem to be correlated with dormancy. Hordeum murinum seeds, which exhibit a dormancy shorter than those of H. marinum, germinate earlier when sown on salt-solutions. Besides, germination energy of H. murinum seeds is, in all assayed solutions, during 260 days from ripening, significantly higher than the one of H. marinum. This species, sown in NaCl solution at concentration 26%, shows a reduced germination capacity. Germination behaviour of the two Hordeum species does not seem to agree with their ecological features as shown by H. marinum. This is present in halophilic associations of coast shores and shows a higher salt-tolerance than H. murinum.