Protoplast fusion between Monostroma nitidum and Porphyra yezoensis and subsequent growth of hybrid plants

Protoplasts from Monostroma nitidum (Chlorophyta) and Porphyra yezoensis (Rhodophyta) were fused utilizing the PEG method. The heterofusants were easily identified by the color of the hybrid cells. The frequency of fusion between the different protoplasts was 1.4%. The heterofusants were transferred into ES medium and cultured. The survival rate of heterofusants after 30 days cultivation was 2-7%. Two plants exhibited hybridizable DNA fragments as compared to parental DNA fragments. Additionally, these two plus a third hybrid plant had characteristic fatty acid components of both the Chlorophyta and Rhodophyta. The results indicate that genetic recombination is possible between these two genera. The field for breeding by protoplasts fusion should be extended across the divisions.