Selection and characterization a new strain (PS-M4) of Pyropia suborbiculata with fast growth based on 60Co-γ ray irradiation

Compared to Pyropia haitanensis, a species of seaweed cultured in southern China, Pyropia suborbiculata exhibits stronger high-temperature resistance but its round shape is unsuitable for commercial culture. To address this, researchers have isolated several long-type mutants and strains from wild-type strain of P. suborbiculata using artificial mutagenesis. However, their growth rates are still relatively slow. In this study, the blades of a long-type strain (PS-5) were irradiated with 60Co-γ rays to determine the optimal mutagenic dose of 1200 Gy. Subsequently, a new strain with fast growth, PS-M4, was selected from its progeny based on growth rate. After 60 days of culture at 23 ℃, the average length and wet weight of PS-M4 blades were 76.3 cm and 1.3 g, respectively, which were 58.2