MOLECULAR ANALYSIS REVEALS CRYPTIC DIVERSITY IN PORPHYRA (RHODOPHYTA)¹

Abstract

The small subunit ribosomal RNA (SSU rRNA) gene was amplified from 15 species of the red alga Porphyra and digested with restriction enzymes to generate data for species identification. The subset of species selected for phylogenetic analysis was P. cuneiforms (Setchell et Hus) Krishnamurthy, P. nereocystis anderson, P. schizophylla Hollenberg et Abbott, P. thuretii Setchell et Dawson and Porphyra 1674. Bangia sp. was used as an out‐group. Restriction sites were mapped and used as characters in parsimony and maximum likelihood analysis. The phylogenetic hypotheses generated were compared statistically to possible alternative phylogenies based on traditional morphological taxonomic characters. The results indicate that the current subgenera in Porphyra do not represent monophyletic groups and that traditional morphological and ecological taxonomic characters alone may not be adequate for definitive species identification and cannot be relied on as an indication of Porphyra have large insertions in the SSU gene that are apparently splicesd from the final SSU rRNA molecule. The possible character, distribution and potential significance of these putative introns are discussed.

Molecular and morphological characters distinguishing twoPorphyraspecies (Rhodophyta: Bangiophycidae)

“…In relation to Porphyra, RFLP (restriction fragment length polymorphism) analysis of the small subunit ribosomal RNA (SSU rRNA) gene has been used to distinguish between species of Porphyra from the Pacific coast of North America (Stiller & Waaland, 1993). The use of molecular, morphological and reproductive evidence to distinguish between species illustrates the value of a holistic approach…”

Molecular genetic analyses of species boundaries in the sea

“…In some of these cases, other kinds of differences had been noted prior to genetic studies (e.g. Brodie et al, 1996;Blomster et al, 1998), while, in other cases the genetic identification of cryptic species came as a complete surprise (Stiller & Waaland, 1993;Benzie et al 1997;Pillman et al, 1997). Not all cryptic species are highly divergent genetically, however (Brodie et al, 1996), and genetic data have also been used to synonymize morphotaxa (Lindstrom & Cole, 1992;Blomster et al, 1998).…”

“…Genera recently examined using genetic techniques include Porphyra (Lindstrom & Cole, 1992;Stiller & Waaland, 1993;Brodie et al, 1996), Phycodris (Van Oppen et al, 1995a,b), Gracilariopsis (Goff et al, 1994), Gracilaria (Goff et al, 1994), Pikea (Maggs & Ward, 1996), Cladophora (Bakker et al, 1995a,b), Caulerpa Pillmann et al, 1997;Olsen et al, 1998) and Enteromorpha (Blomster et al, 1998). These taxa include economically important species (Porphyra, Gracilaria, Gracilariopsis), as well as bioindicators of pollution (Enteromorpha) and pest species (Caulerpa).…”

<p align="left"><strong>A new species of <em>Pyropia</em> (Rhodophyta, Bangiaceae), from the Pacific coast of Mexico, based on morphological and molecular evidence</strong></p>

“…raulaguilarii mentioned here. Table 2 shows the vegetative and reproductive characters of various species of Pyropia and in it observed the (Stiller & Waaland 1993, Oliveira et al 1995, Broom et al 1999, Kunimoto et al 1999 have revealed considerable interspecies diversity of the nrSSU and rbcL regions within this genus and suggest that provides useful characters for species identification.…”