Research on seed dormancy breaking and germination methods of five typical annual herbaceous plants in the desert-oasis ecotone of the Hexi Corridor, China

Annual herbaceous plants are important components of arid desert flora and play irreplaceable ecological roles in the restoration and protection of desert ecosystems. In this study, we selected five typical annual herbaceous species—Agriophyllum squarrosum, Halogeton arachnoideus, Bassia dasyphylla (Chenopodiaceae), and Setaria viridis and Chloris virgata (Gramineae)—as study subjects under artificial forests in a typical desert-oasis ecotone in the Hexi Corridor. We measured seed water absorption, viability, and germination rates of seeds preserved for one and two years. To investigate dormancy characteristics and breaking methods, seeds were treated with different methods, including polyethylene glycol, pre-cooling, pre-heating, GA₃ and KNO₃. The results showed that all five species had high seed viability ( > 77.33%) and exhibited physiological dormancy. Pre-cooling and treatment with GA₃ (0.02%, 0.05%, 0.10%) or KNO₃ (0.20%, 0.50%, 1.00%) increased germination rates. Among treatments, Agriophyllum squarrosum showed the highest germination rate with 1.00% KNO₃. Halogeton arachnoideus, Bassia dasyphylla, and Chloris virgata showed the highest rates with 0.05% GA₃, while Setaria viridis had the highest germination rate with pre-cooling treatment. This study provides a scientific basis for utilizing dominant annual herbaceous species in the arid desert-oasis transition zone and for the restoration and reconstruction of desert vegetation.