Responses of caryopsis germination, early seedling growth and ramet clonal growth of Bromus inermis to soil salinity

Bromus inermis is a dominant rhizomatous grass in Otindag Sandland of North China, where soil salinization is increasing. We studied responses of caryopsis germination, early seedling growth and ramet integrative growth of this clonal plant to salinity. Caryopses germinated in NaCl solutions ≤0.2 M. Ungerminated caryopses treated with >0.02 M NaCl germinated after transfer to 0.02 M NaCl, and percentage germination recovery increased with treatment NaCl concentration. No seedlings survived NaCl concentrations >0.3 M. At 0.3 M NaCl, biomass and height of seedlings significantly decreased with increase in treatment NaCl concentration, but root/shoot ratio significantly increased. Ramets exposed to high salinity survived if interconnected to a neighbour ramet not exposed to salinity. However, if interconnections were severed ramets exposed to high salinity died. Thus, B. inermis is adapted to the saline environment in Otindag Sandland in both the asexual and sexual stages of its life cycle.