Comparative study of wild and cultivated Porphyra yezoensis (Bangiales, Rhodophyta) based on molecular and morphological data

Abstract

We compared the wild Porphyra strain OGATSU from northeastern Japan with cultivated Porphyra yezoensis f. narawaensis using the RuBisCO spacer, rbcL, and ITS-1 DNA sequences as well as early gametophyte development. Based on the molecular analyses and detailed morphological observations, OGATSU was identified as P. yezoensis, but also revealed important differences from the cultivated form. Under the same culture conditions, gametophytic blades of OGATSU produced more archeospores than P. yezoensis f. narawaensis strain HG-4. The length of blades and their length-to-width ratios were significantly lower in OGATSU than in HG-4, and the color of OGATSU blades was darker than that of HG-4. The first lateral cell division in conchospore germlings occurred significantly earlier in the OGATSU strain than in the HG-4 strain, resulting in the rounder shape of the OGATSU blade compared to that of P. yezoensis f. narawaensis. These results suggested that wild strains such as OGATSU can provide useful characters that could enhance cultivated varieties in a careful breeding program.

Molecular divergence and application of the ITS-5.8S rDNA and RUBISCO spacer in Porphyra haitanensis Chang et Zheng (Bangiales, Rhodophyta)

“…The same result has also been reported for P. yezoensis strains (Niwa et al 2008a). Therefore, the RUBISCO spacer is not suitable for the discrimination of P. haitanensis strains, but it is a valuable marker for discriminating different Porphyra species (Brodie et al 1998).…”

Origin identification of dried seaweed product “nori” by PCR–RFLP analysis of Pyropia yezoensis in the internal transcribed spacer ITS-1 region

“…In Japanese products, the genetic variation of P. yezoensis was very low, and the nucleotide sequences in the ITS region of almost all products were identical to the genotype Japan_Sub01, which corresponded to the reference strains of P. yezoensis f. narawaensis (i.e., U-51, Saga-5, Sasiki, Fukuoka-1, Ariake-1, and Saga103) [5,8]. The two exceptional cases in which we detected the genotype Japan_Sub02 may have been due to contamination by wild strains in the aquaculture field.…”

“…The box represents an MspI site. The partial nucleotide sequence in the ITS-1 region of the Japan_Sub01 genotype identical to that of P. yezoensis f. narawaensis [5,8] is underlined, and used for the phylogenetic analysis in Fig. 3.…”

“…and P. yezoensis strains have been developed previously. DNA fingerprinting and PCR-based restriction fragment length polymorphism (RFLP) analysis have been conducted using small subunit ribosomal RNA [4], internal transcribed spacer region (ITS) [2,[5][6][7][8], plastid ribulose bisphosphate carboxylase/oxygenase gene (RuBisCo) [6][7][8], and actinrelated protein 4 gene [9]. Park et al [10] reported genetic polymorphism within wild-collected P. yezoensis from Japan and Korea.…”

“…Mitochondrial DNA was also used for the discrimination of 18 Japanese Porphyra and Pyropia species [12]. From these previous studies, Kunimoto et al [2] and Niwa et al [8] reported diverse nucleotide sequences in the ITS region among P. yezoensis wild-collected and culture strains. Therefore, to develop origin identification techniques for dried nori products, nucleotide sequences in the ITS region are required to determine and compare the thalli DNA extracted from dried nori products produced in Japan, Korea, and China.…”