Ethyl methanesulfonate mutant library construction in Neopyropia yezoensis to provide germplasm resources for next-generation genome-selection breeding

Abstract

With the development of the laver industry, germplasm depression has become a serious issue, and current cultivars cannot adapt to different aquaculture regions. In order to increasing the genetic diversity and developing more germplasm sources, it is urgent and reasonable to construct a mutant library with more new germplasms. In this research, a mutant library was constructed by ethyl methanesulfonate (EMS)-mutagenized archeospores, and the most optimal treatment procedure was determined by performing different mutagen concentrations (2.25%) and treatment times (30 min). A total of 1860 haploid thalli were produced as the M1 mutant population and further cultured into conchocelis clones for the reservation of germplasm resources. Among these, 667 individual thalli were evaluated for their phenotypic traits, including thallus length, thallus width, length/width, thallus shape, photosynthesis ability, thallus color, thallus margin, and specific growth speed. The mutation frequency of the length/width ratio was 17.39%, Fv/Fm and NPQ were 21.84% and 29.35%, respectively, and SGR was 13.59%. The mutation frequency of thallus color was 0.91%. This work may not only provide a basic practical reference guide for EMS-based mutant library construction for other seaweeds but, more importantly, also serve as a valuable resource for functional genomics research and laver breeding.

Genome editing in macroalgae: advances and challenges

“…( Levy and Friedlander, 1990 ; Hayashi et al, 2007 ; Su et al, 2020 ; Lawton et al, 2021 ). Cultivars have been generated using a variety of techniques, including traditional selection, heavy ion radiation, and ethyl methanesulfonate (EMS) mutagenesis ( Niwa et al, 2011 ; Park and Hwang, 2014 ; Lee and Choi, 2018 ; Hwang and Park, 2020 ; Kong et al, 2023 ). Nevertheless, whereas land plants which have been cultivated and gradually domesticated for more than 12,000 years ( Purugganan, 2019 ), the earliest record of deliberate seaweed cultivation dates back to about 400 years ago in Korea ( Hwang and Park, 2020 ).…”