Optimization of the germination of edible Mediterranean wild halophytes

Abstract

Despite the growing interest on the commercial exploitation of salt tolerant plants (halophytes), either as food or sources of bioactive products, scientific efforts for its cultivation are scarce, and there is a need to develop production systems that are economically, socially and environmentally feasible [1], [2], [3]. This work aimed to optimize the germination of 8 edible halophytes, targeting treatments to break seed dormancy (gibberellic acid, chemical and mechanical scarification, water soaking and thermal shock), substrate (perlite, vermiculite, sand, coco peat, and combinations) and irrigation salinity (freshwater and 20.1 mS/cm). Germination percentages were in the range 11.1 – 95.6%; Mesembryanthemum crystallinum, Salicornia ramosissima, Inula crithmoides and Portulaca oleracea had germination rates above 50%. Mean germination times (MGT) ranged from 5 – 28 days, with P. oleracea displaying the best result (5 – 6.9 days) with freshwater irrigation. There was no relation between best germination rate and lower MGT. Seed treatments to break dormancy in M. nodiflorum, Medicago marina and Ammophila arenaria improved their germination in 7.8, 42.2 and 35.5% compared to the control. Notwithstanding that halophytes grow in saline environments, our results indicates that the germination of some species is compromised by salinity, and also that a treatment to break seed dormancy is required. The authors declares that there is no conflict of interest.