Rapid discrimination of <Emphasis Type="Italic">Porphyra tenera</Emphasis> Kjellman var. <Emphasis Type="Italic">tamatsuensis</Emphasis> Miura by PCR-RFLP

To allow to discriminate rapidly the strains of Porphyra tenera var. tamatsuensis, cultivars of which grow more vigorously than strains of P. tenera var. tenera, strains of both varieties were examined by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis using mitochondrial DNA related to the ATP synthase F0 subunit 6 (ATP6) gene. The lengths of all sequences in this region of three strains of each variety were 670 bp and had just a single nucleotide substitution. Digestion with the restriction enzyme of TaaI yielded three visible bands which appeared in the three strains of P. tenera var. tamatsuensis, whereas two bands appeared in the three strains of P. tenera var. tenera. We therefore conclude that PCR-RFLP analysis is a valuable tool for discrimination of P. tenera var. tamatsuensis among the stock of P. tenera strains used for mariculture.