The characterization of color mutations in Bangiaceae (Bangiales, Rhodophyta)

The color mutations in Bangiaceae were investigated by treating the blades, conchocelis and conchospores phase of Bangia sp., Porphyra yezoensis , and P. haitanensis sampled in China with mutagen N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). A high percentage of mutation in different expression characteristics in all three phases were shown within optimum mutagen concentrations. Among mutagenized blades, mutations occurred on single cells, which is a direct outcome of mutation of haploid cells. The mutation of mutagenized conchocelis resulted in a two-step process: low-level expression in conchocelis phase, and high-level expression in progeny, explaining that mutation took place in diploid cells. The mutations of conchospores were expressed immediately at germination of spores, indicating a change in ploidy. This paper reports the process of meiosis and its effect on frond development, and the relation between color mutations and morphological characteristics expressed by mutations in Bangiaceae.