Comparison of salt tolerance during the germination period of 12 grass species under severe salt stress

In order to screen grass species suitable for planting in coastal areas characterized by saline soils, we selected a range of grasses, including Poa pratensis, Festuca arundinacea, and Lolium perennia, as materials to determine their germination indices, growth dynamics, and root systems under salt stress induced by 300 mmol·L^–1 NaCl and 50 mmol·L^–1 MgSO₄ salt solutions applied via moistened filter paper. The results revealed that the two species L. perenne and F. arundinacea had the highest salt tolerance. Although the reduction in grass germination under salt stress was no higher than 20% and the effects were non-significant, the suppression of shoot and root growth was greater than 50% compared with that of control plants (P < 0.05). Total root system length, total root system areas, and lateral root number were all reduced by more than 50%. For Agrostis and Trifolium, the reduction in the average diameter of the root system in response to salt stress was between 0% and 100%. Three species with higher salt tolerance were L. perenne, F. arundinacea, and F. sinensis. Amongst the L. perenne varieties, γ, Gentry, and Barlennium showed higher salt tolerance, whereas among Festuca spp., the cultivars Fire Phoenix2, BarvadoⅡ, and Naihan showed higher salt tolerance. Similarly, among Trifolium spp., cultivars with salt tolerance were Super-Huia in T. repens, Dolly in T. pratense, and Cherry in T. incarnatum. Furthermore, among Poa pratensis varieties, those with a higher salt tolerance were Merit, Baron, and Blue Chip, whereas among Agrostis spp., the cultivars A-1, Kromi BT, Impala, and Highland all had higher salt tolerance.