The Crustose Brown Algae of New Zealand: a Taxonomic Study

<p>Nine species of crustose brown algae are described from New Zealand’s coast. Three species are microthalli of species of Scytosiphonaceae: Colpomenia bullosa Yamada, Scytosiphon lomentaria (Lyngbye) Link and Petalonia binghamiae (J. Agardh) Vinogradova. One species of Lithodermataceae, Pseudolithoderma roscoffense Loiseaux is described from Northland. Four species are Ralfsiaceae, Ralfsia expansa (J. Agardh) J. Agardh, Ralfsia confusa Hollenberg, a new species, Ralfisa sp. “smooth”, and Hapalospongidion gelatinosum Saunders. H. saxigenum Lindauer is identical to Hapalospongidion gelatinosum Saunders. One new species of Diplura, currently placed in the Ralfsiaceae, is described. Ralfsia verrucosa (Areschoug) Areschoug, previously reported from New Zealand, was not found. ITS-2 sequences show that Ralfsia expansa, Ralfsia confusa and Ralfsia sp. “smooth” are closely related. Ralfsia expansa is more distantly related. These relationships are consistent with morphological differences. LSU nrDNA sequences show Diplura sp. and Pseudolithoderma roscoffense are not closely related to other Ralfsiaceae. These algae form a weakly supported group with members of the Sphacelariales. Hapalospongidion and three Ralfsia species form a well supported group, but this group’s relationship to other phaeophycean orders is not resolved. These results are discussed in relation to plastid number and the status of the order Ralfsiales.</p>

The Crustose Brown Algae of New Zealand: a Taxonomic Study

<p>Nine species of crustose brown algae are described from New Zealand’s coast. Three species are microthalli of species of Scytosiphonaceae: Colpomenia bullosa Yamada, Scytosiphon lomentaria (Lyngbye) Link and Petalonia binghamiae (J. Agardh) Vinogradova. One species of Lithodermataceae, Pseudolithoderma roscoffense Loiseaux is described from Northland. Four species are Ralfsiaceae, Ralfsia expansa (J. Agardh) J. Agardh, Ralfsia confusa Hollenberg, a new species, Ralfisa sp. “smooth”, and Hapalospongidion gelatinosum Saunders. H. saxigenum Lindauer is identical to Hapalospongidion gelatinosum Saunders. One new species of Diplura, currently placed in the Ralfsiaceae, is described. Ralfsia verrucosa (Areschoug) Areschoug, previously reported from New Zealand, was not found. ITS-2 sequences show that Ralfsia expansa, Ralfsia confusa and Ralfsia sp. “smooth” are closely related. Ralfsia expansa is more distantly related. These relationships are consistent with morphological differences. LSU nrDNA sequences show Diplura sp. and Pseudolithoderma roscoffense are not closely related to other Ralfsiaceae. These algae form a weakly supported group with members of the Sphacelariales. Hapalospongidion and three Ralfsia species form a well supported group, but this group’s relationship to other phaeophycean orders is not resolved. These results are discussed in relation to plastid number and the status of the order Ralfsiales.</p>

Protoplast isolation from Dictyopteris pacifica and Scytosiphon lomentaria, using a simple commercial enzyme preparation

Background Protoplasts (i.e., naked plant cells) can be used for in vitro manipulations and genetic improvement in cultivars with economic value. During the last decade, protoplast research in economic brown algae has been scarce, and it is usually hampered by the use of non-commercial enzymes or crude extracts for isolating protoplasts. Dictyopteris pacifica is part of a brown algal genus well known by its wide chemical diversity and biological properties. Scytosiphon lomentaria is an edible brown seaweed with antioxidant, antitumor, and antiviral properties. So far, there are no protoplast isolation protocols using commercial enzymes for these two economic brown algae. In this study, we obtained protoplasts from cultured samples of D. pacifica and S. lomentaria using commercially available enzymes. Additionally, we investigated the effects of Driselase inclusion and Ca-chelation pre-treatment on protoplast yields in order to optimize the conditions for protoplast preparations. Results Protoplasts were isolated from Dictyopteris pacifica and Scytosiphon lomentaria using the commercially available Cellulase Onozuka RS (1%) and Alginate lyase (4 U mL−1), and short incubation time (4 h). Driselase did not show significant effects on protoplast production in both species. Ca-chelation pre-treatment only increased the number of protoplasts in D. pacifica. Under optimal conditions, the protoplast yields from D. pacifica and S. lomentaria were 4.83 ± 2.08 and 74.64 ± 32.49 × 106 protoplasts g−1 fresh weight, respectively. The values obtained for S. lomentaria were 2–3 orders of magnitude higher than previously reported. Conclusions Our results show that high protoplast yields can be obtained from D. pacifica and S. lomentaria using a simple mixture of commercial enzymes (Cellulase RS and Alginate lyase) and short incubation time (4 h). This work also represents the first report of protoplast isolation in D. pacifica. The method proposed here can help to expand protoplast technology in more brown algal species.

Geographic parthenogenesis in the brown alga Scytosiphon lomentaria (Scytosiphonaceae): sexuals in warm waters and parthenogens in cold waters

Geographic parthenogenesis (GP), a phenomenon where parthenogens and their close sexual relatives inhabit distinct geographic areas, has been considered an interesting topic to understand the adaptation to marginal habitats and the role of hybridization in evolution. Reports of GP from land and freshwater are numerous, however, this occurrence has been rarely reported on from the sea. Brown algae are mostly marine and are thought to include numerous obligate parthenogens; still, little is known about the distribution, origin, and evolution of parthenogens in this group. Here we report a novel pattern of GP in the isogamous brown alga Scytosiphon lomentaria. Sex ratio investigation demonstrated that, in Japan, sexual populations grew in the coast along warm ocean currents, whereas female-dominant parthenogenetic populations grew mainly in the coast along a cold ocean current. In the two localities where sexual and parthenogenetic populations were parapatric, parthenogens grew in more wave-exposed areas than sexuals. Population genetic and phylogenetic analyses, including those based on genome-wide single nucleotide polymorphism data, suggested that: (1) parthenogens evolved at least twice in S. lomentaria, (2) parthenogens did not originate from inter-species hybridization, (3) new parthenogenetic lineages have arisen from hybridizations between parthenogens and sexuals, and (4) parthenogens have a wider distribution than sexuals. We also showed that the production of sex pheromones, which attract male gametes, has been independently suppressed/lost in two parthenogenetic lineages. This parallel suppression/loss of the sexual trait may represent the direct origin of parthenogens, or the regressive evolution of a useless trait under asexuality.

Isolation of Antibiotic 3R,5R-Dihydroxyhexanoate Polymers From Endophytic Fungi

The extracts of two isolates in our library of fungal endophytes, Annulohypoxylon multiforme (TC2-046) from the medicinal plant Juniperus communis and a sterile filamentous isolate (KP1-131DD) from the marine alga Scytosiphon lomentaria, displayed similar antimicrobial bioactivity profiles with notable high activity against Staphylococcus aureus. Bioassay-guided fractionation led to the isolation of poly(3 R,5 R-dihydroxyhexanoic acid) oligomers ranging from the trimer to the 29-mer that exhibited significant and selective inhibition of S. aureus and Mycobacterium tuberculosis H37Ra in vitro.