Rubisco Spacer Research Articles

Exploration and growth characteristics of allopolyploids derived from interspecific hybridization between Neopyropia yezoensis and Neopyropia tenera (Bangiales, Rhodophyta) in natural populations of eastern Japan

We investigated the distribution of allopolyploids of the red algal genus Neopyropia (referred to as nori) in natural populations of eastern Japan and compared the growth characteristics of allopolyploids and ancestral species under laboratory culture. To detect hybrids between Neopyropia yezoensis and Neopyropia tenera, 99 samples collected from 7 localities were examined by sequence analysis of the chloroplast RUBISCO spacer region and DNA marker analyses of two nuclear genes. The results indicated that 20 samples were hybrids derived from interspecific hybridization between the two species. Using 5 conchocelis strains among the hybrids, the blades that developed from both conchospores and archeospores were obtained under laboratory culture and were examined by nuclear DNA marker analyses to confirm allopolyploidy. As a result, the five strains were confirmed as allopolyploids derived from interspecific hybridization between N. yezoensis as the maternal strain and N. tenera as the paternal strain. Furthermore, from two of the five strains, the allopolyploid strains TUYTA-7 and TUYTA-8 were established via self-fertilization of the blade from an archeospore, and the blade growth and photosynthetic pigments of the two strains were compared with those of the strain UM-T55 of the ancestral species N. tenera collected from the same origin site as the two strains. In the allopolyploid strains, the TUYTA-8 blades exhibited superior characteristics, such as a long and linear shape, rapid elongation, low fertility and high pigment content. These results imply the importance of exploring and isolating more allopolyploid strains in bladed Bangiales. Moreover, it is possible that polyploid breeding due to interspecific hybridization in the bladed Bangiales will become more popular as a practical method for developing new cultivars of nori.

Contrasting patterns of genetic diversity and population discontinuity in the common red seaweed Gracilaria salicornia (Gracilariaceae) along the coasts of Thailand

ABSTRACT For long-term management and conservation of marine resources an understanding of their genetic diversity and geographic distribution is necessary. The red alga Gracilaria salicornia is widely distributed along the coasts of Thailand and has been used as food and as fertilizer. However, there have been no studies examining the genetic diversity of this alga. The present research aimed to employ two different genetic markers, mitochondrial (COI-5P) and chloroplast (RuBisCO spacer) for exploring the genetic diversity and phylogeography of G. salicornia in Thailand. Our analyses, inferred from both markers, revealed different levels of genetic diversity between the two coasts of Thailand, and the recognition of seven new COI haplotypes. Gracilaria salicornia in the Andaman Sea had higher genetic diversity than in the Gulf of Thailand. Significant genetic divergence was found between populations in the Andaman Sea and the Gulf of Thailand, likely due to the geographic barrier of the Thai-Malay Peninsula and the complex ocean currents. No genetic structuring was detected in the Gulf of Thailand, whereas low to moderate genetic differentiation was found between populations in the Andaman Sea, suggesting a possible break between the northern and southern Andaman Sea. This break could be explained by ocean circulation patterns around the Malacca Strait. These findings provide further evidence supporting the Thai-Malay Peninsula and oceanographic currents as strong barriers to dispersal, leading to genetic differentiation and population structuring of G. salicornia and other marine species. These results can be used to guide conservation management actions and exploitation of this marine resource.

Assessment of the macroalgal diversity of Kuwait by using the Germling Emergence Method

Cryptic stages of diverse macroalgae present in natural substrata, “the bank of microscopic forms”, were isolated into clonal cultures and identified based on both morphological characteristics and DNA barcoding. Approximately 120 clonal isolates from 308 natural substratum samples were collected from the entire coastline of Kuwait. Amongst these isolates, 77 (64%) were identified through DNA barcoding using the nuclear ribosomal small subunit, RuBisCO spacer (ITS2, <i>tufa</i>, <i>rbc</i>L, <i>psa</i>A, and <i>psb</i>A) and sequencing. Twenty-six isolates (34%) were identified in the division Chlorophyta, 18 (23%) as Phaeophyceae, and 33 (43%) as Rhodophyta. For all DNA sequences in this study, species-level cut off applied was ≥98% homology which depend entirely on the markers used. Three putative new records of Chlorophyta new for the Arabian Gulf were made: <i>Cladophora laetevirens</i> (Dillwyn) Kützing, <i>Ulva torta</i> (Mertens) Trevisan and <i>Ulvella leptochaete</i> (Huber) R. Nielsen, C. J. O′Kelly & B. Wysor in Nielsen, while <i>Cladophora gracilis</i> Kützing and <i>Ulva ohnoi</i> M. Hiraoka & <i>S. Shimada</i> are new records for Kuwait. For Phaeophyceae, Ectocarpus subulatus Kützing and <i>Elachista stellaris</i> Areschoug were new records for the Gulf and Kuwait. In the Rhodophyta, <i>Acrochaetium secundatum</i> (Lyngbye) Nägeli in Nägeli & Cramer, <i>Ceramium affine</i> Setchell & N. L. Gardner, <i>Gelidium pusillum</i> var. <i>pakistanicum</i> Afaq-Husain & Shameel and <i>Dasya caraibica</i> Børgesen are new records for the Gulf and Kuwait, while the red alga <i>Stylonema alsidii</i> (Zanardini) K. Drew is a new record for Kuwait. Several isolates identified corresponded to genera not previously reported in Kuwait and / or the Arabian Gulf, such as <i>Porphyrostromium</i> Trevisan, a new genus from the Bangiales, and two unidentified species for the Planophilaceae Škaloud & Leliaert. The isolates cultivated from substrata enhance understanding of the marine macroalgal diversity in the region and confirmed that the Germling Emergence Method is suitable for determining the actual diversity of a given study area through isolation from cryptic life-history phases.

Deep genetic divergences and geographic distribution of the red algal genus Caulacanthus (Gigartinales)

An increasing number of studies have demonstrated that genetic differentiation and cryptic diversity in the sea occur over considerably smaller spatial scales than previously comprehended, considering the wide distribution range of many morphologically defined macroalgal species. However, knowledge of the turf-forming red alga Caulacanthus is incomplete regarding its species diversity, as well as genetic differentiation within the genus. We analyzed Caulacanthus specimens from the NW Pacific, NE Pacific, Central Pacific, SW Pacific, SE Indian, NE Atlantic, and SE Atlantic Ocean using mitochondrial cytochrome oxidase subunit I (COI-5P), plastid ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL), and Rubisco spacer (rbcL-S). The objectives of this study were to 1) determine the number of species that exhibit the morphology of C. ustulatus, 2) investigate the present distribution pattern of Caulacanthus species, and 3) estimate the degree of genetic connectivity between the populations of Caulacanthus species from different regions. Our results revealed molecular evidence that the genus Caulacanthus comprises of at least seven species with deep genetic divergence, which is indicative of not only a strong geographical subdivision but also a relatively long temporal discontinuity. Most species exhibited limited geographic distribution, showing considerable genetic divergence in the populations isolated by distance. Our study provides evidence of a greater evolutionary independence of Caulacanthus populations, which have undergone a series of allopatric diversification events.

New records of Palisada tenerrima and Hincksia mitchelliae from the Maltese Islands revealed by molecular analysis

We report two new algal records from the Maltese islands: Hincksia mitchelliae (= Feldmannia mitchelliae) (Phaeophyceae) and Palisada tenerrima (Rhodophyceae). The former species was grown in culture from an Ulva sp. blade, while the latter was collected in the field. Our study employed an innovative integrative approach including morphological criteria as well as molecular analysis. DNA data and subsequent phylogenetic analysis of the COI gene and the rbcL plus RuBisCO spacer supported the separation of these two species from the closest-related congeners that had previously been reported from the Maltese islands.

Phylogeographic patterns in cryptic <italic>Bostrychia tenella</italic> species (Rhodomelaceae, Rhodophyta) across the Thai-Malay Peninsula

Genetic diversity and distribution patterns of marine macroalgae are increasingly being documented in Southeast Asia. These studies show that there can be significant levels of genetic diversity and isolation between populations on either side of the Thai-Malay Peninsula. Bostrychia tenellla is a common filamentous red seaweed in the region and the entity is represented by at least two cryptic species. Despite being highly diverse and widespread, genetic variation and population structure of this species complex remains understudied, especially around the Thai-Malay Peninsula. We analyzed genetic diversity and inferred the phylogeographic pattern of specimens identified as B. tenella using the plastid RuBisCo spacer from samples from the Andaman Sea and the Gulf of Thailand. Our genetic analysis confirmed the occurrence of the two cryptic B. tenella species (B and C) along both coasts. Cryptic species B was more common in the area and displayed higher genetic diversity than species C. Historical demographic analyses indicated a stable population for species B, but more recent population expansion for species C. Our analyses also revealed that both cryptic species from the Andaman Sea possessed higher genetic diversity than those of the Gulf of Thailand. We also detected moderate to high levels of gene flow and weak phylogeographic structure of cryptic species B between the two coasts. In contrast, phylogeographic analysis showed genetic differences between populations of both cryptic species within the Andaman Sea. Overall, these results suggest that cryptic B. tenella species around Thai-Malay Peninsula may have undergone different demography histories, and their patterns of genetic diversity and phylogeography were likely caused by geological history and regional sea surface current circulation in the area.

Potential of Neoporphyra kitoi (Bangiales, Rhodophyta) as a candidate species for marine crops with high temperature tolerance

We isolated the conchocelis strain OHN-1 from a long linear blade growing in a natural population of bladed Bangiales in Ohara, Chiba Prefecture, the Boso Peninsula in Japan, which is affected by the warm Kuroshio Current. The strain was identified as Neoporphyra kitoi based on the RUBISCO spacer sequences and phylogenetic analysis of the rbcL gene. Under identical laboratory cultures, the growth and pigment contents of the strain were compared with those of Neopyropia yezoensis f. narawaensis, which is the main cultivar currently cultivated in Japan. The conchocelis maturity of OHN-1 was remarkably higher than that of strain HG-4 of Neopy. yezoensis f. narawaensis at higher temperatures of 25 and 30 °C among the 5 temperature conditions (10, 15, 20, 25, 30 °C). The growth of the gametophytic blade was significantly higher in OHN-1 than in HG-4 at each examined temperature (15, 20, 25 °C). In particular, the OHN-1 blades at the highest temperature of 25 °C grew the largest until 3 weeks of culture, although the blades grew larger over 3 weeks with decreasing temperature. Moreover, the photosynthetic pigment contents, especially the phycoerythrin content, were significantly higher in OHN-1 than in HG-4. These results demonstrate that Neoporphyra kitoi has potential as a candidate species for marine crops with high temperature tolerance despite faster blade maturity.

DNA barcoding of marine algae from Malta: new records from the central Mediterranean

The heterokont benthic multicellular algae Schizocladia ischiensis E.C. Henry, K. Okuda et H. Kawai (Schizocladiophyceae), Hecatonema terminale (Kützing) Kylin and Striaria attenuata (Greville) Greville (Phaeophyceae) are reported for the first time from the waters around the Maltese islands in the central Mediterranean. They were identified through algal isolation from incubated natural substrata, coupled with DNA barcoding targeting the biomarkers COI and rbcL plus the RuBisCO spacer. For three additional brown algae, Colpomenia sinuosa (Mertens ex Roth) Derbès et Solier, Asperococcus bullosus J.V.Lamouroux and Sphacelaria sp., DNA sequences confirmed previous morphology-based records from Malta. This paper also provides an updated literature-based species list of the marine macroalgae present in Malta.

First record of Neoporphyra haitanensis (T.J.Chang & B.F.Zheng) J.Brodie & L.‐E.Yang (Bangiales, Rhodophyta) from Shikinejima Island and Hachijojima Island of the Izu Islands, southern central Japan

SUMMARYWe conducted a morphological observation and molecular phylogenetic analyses on bladed Bangiales collected from natural populations on Shikinejima Island and Hachijojima Island of the Izu Islands, southern central Japan. The morphological features of the gametophytic blades such as the blade shape, blade margin and reproductive cell divisions were extremely similar to those parameters of Neoporphyra haitanensis, a species cultivated in southern China, and Neoporphyra dentata. However, the blades collected from the two islands were thicker than the blades of N. dentata; this feature was the same as that of N. haitanensis. The chloroplast RUBISCO spacer sequences of present samples were identical to the sequences of N. haitanensis from China. Moreover, phylogenetic positions of three conchocelis strains isolated from the blades on the two islands were examined based on concatenated sequences of the chloroplast rbcL gene and nuclear 18S rRNA. The results showed that the strains were resolved in a clade including N. haitanensis; however, the strains were separated from N. haitanensis in China. Therefore, the bladed Bangiales from the two islands were identified as N. haitanensis. The present study is the first record of N. haitanensis in natural populations in Japan.

Identification, growth, and pigment content of a spontaneous green mutant of Pyropia kinositae (Bangiales, Rhodophyta)

A green-colored gametophytic blade of wild Pyropia was found in a natural population in the estuary area of the Naruse River, northeast Japan. To identify the isolated green mutant strain K-G1 and the wild-type strain K-1 derived from the same population, we carried out morphological observations and molecular analysis of the RUBISCO spacer region and the rbcL gene. As a result, the two strains were identified as Pyropia kinositae, which is a species closely related to the marine crop Pyropia yezoensis. Under the same laboratory culture, the growth and pigment contents of the green mutant K-G1 were compared with those of the wild-type K-1. The growth of the conchocelis and gametophytic blade tended to be slower in the green mutant than in the wild type, although differences in their growth were not apparent in some of the temperature conditions examined. Maturation of the conchocelis and blade in the two strains was fastest at 20 °C among the temperature conditions examined (5–25 °C). The phycoerythrin content was significantly lower in the green mutant than in the wild type. Additionally, the color phenotype of the green mutant was genetically stable in both the sporophytic conchocelis and gametophytic phases. Because the color of a pigmentation mutant facilitates cross-confirmation as a genetic marker in monoecious Pyropia species, these results suggest that the green mutant of P. kinositae will contribute as new breeding material for cross-breeding and polyploidy breeding in Pyropia.

The Minute Alga Schizocladia ischiensis (Schizocladiophyceae, Ochrophyta) Isolated by Germling Emergence from 24 m Depth off Rhodes (Greece)

Substratum collected during diving surveys of sublittoral communities off the Greek island of Rhodes (Dodecanese, South-East Aegean) in late 2015 was incubated in the laboratory. Among the emerging macroalgal germlings, there was the second-ever record and isolate of the small benthic multicellular alga Schizocladia ischiensis of the poorly known monotypic Schizocladiophyceae, the sister group of the brown algae (Phaeophyceae). Its nuclear ribosomal small subunit, Rubisco spacer (rbcL, psaA, and psbC sequences (in total 5237 bp)) were similar to those of the only previous isolate of the species from Ischia, western Mediterranean. Our new strain formed branched upright thalli attached to the substratum by an amorphous substance secreted at the bottom of the basal cell. It is possible that S. ischiensis is a common member of the infralittoral and circalittoral communities in the Mediterranean and generally overlooked because of its minute size. Germling emergence appears to represent the method of choice to reveal benthic algae of this small size.

Eucheumatopsis isiformis gen. & comb. nov. (Solieriaceae, Rhodophyta) from the Yucatan Peninsula, to accommodate Eucheuma isiforme

ABSTRACTOn the basis of COI-5P, cox2–3 spacer, RuBisCo spacer, and rbcL sequences, Eucheuma was resolved as a paraphyletic genus in the Solieriaceae. Specimens of E. isiforme from the Yucatan Peninsula and Florida form an independent lineage in the family that was also different from E. denticulatum, the generitype. To accommodate this species, we described Eucheumatopsis as a new genus that differs from Eucheuma both molecularly and geographically. Because the four molecular markers used and morphological characters did not support the independence of Eucheuma isiforme var. denudatum from E. isiforme var. isiforme, we have proposed to no longer recognize var. denudatum as a separate variety.

Tepoztequiella rhizoidea gen. et sp. nov. (Solieriaceae, Rhodophyta) from the Yucatan Peninsula, Mexico

:Molecular methods have greatly aided in discovering new diversity in many cryptic algal groups. Molecular-assisted species discovery has focused morphological analyses on previously overlooked taxa, leading to a better understanding of diversity and evolutionary patterns. The Yucatan Peninsula, as a junction of North and South American Atlantic floras, is very diverse and, while a well-explored area, continues to reveal new species. Our studies in this area have revealed a new cylindrical member of the Solieriaceae. Based on COI-5P, rbcL and RuBisCo spacer sequences, we show that this entity is phylogenetically unique. Its position in phylogenetic analyses, combined with morphological characters and the genetic divergence from other species and genera within the family, strongly supports the establishment of Tepoztequiella rhizoidea gen. & sp. nov. The diagnostic character of T. rhizoidea is the presence of many rhizoids arising from medullary filaments and from the cells of the inner cortex.

Historical isolation and contemporary gene flow drive population diversity of the brown alga Sargassum thunbergii along the coast of China

BackgroundLong-term survival in isolated marginal seas of the China coast during the late Pleistocene ice ages is widely believed to be an important historical factor contributing to population genetic structure in coastal marine species. Whether or not contemporary factors (e.g. long-distance dispersal via coastal currents) continue to shape diversity gradients in marine organisms with high dispersal capability remains poorly understood. Our aim was to explore how historical and contemporary factors influenced the genetic diversity and distribution of the brown alga Sargassum thunbergii, which can drift on surface water, leading to long-distance dispersal.ResultsWe used 11 microsatellites and the plastid RuBisCo spacer to evaluate the genetic diversity of 22 Sargassum thunbergii populations sampled along the China coast. Population structure and differentiation was inferred based on genotype clustering and pairwise FST and allele-frequency analyses. Integrated genetic analyses revealed two genetic clusters in S. thunbergii that dominated in the Yellow-Bohai Sea (YBS) and East China Sea (ECS) respectively. Higher levels of genetic diversity and variation were detected among populations in the YBS than in the ECS. Bayesian coalescent theory was used to estimate contemporary and historical gene flow. High levels of contemporary gene flow were detected from the YBS (north) to the ECS (south), whereas low levels of historical gene flow occurred between the two regions.ConclusionsOur results suggest that the deep genetic divergence in S. thunbergii along the China coast may result from long-term geographic isolation during glacial periods. The dispersal of S. thunbergii driven by coastal currents may facilitate the admixture between southern and northern regimes. Our findings exemplify how both historical and contemporary forces are needed to understand phylogeographical patterns in coastal marine species with long-distance dispersal.

Advancing the taxonomy of economically important red seaweeds (Rhodophyta)

ABSTRACTThe cultivation of red seaweeds for food (nori), agar and carrageenans is the basis of a valuable industry. However, taxonomic knowledge of these cultivated seaweeds and their wild relatives has not kept pace with advances in molecular systematics despite the fundamental importance of being able to identify commercially important species and strains, discover cryptic and endemic taxa and recognize non-native species with potentially damaging diseases and epiphytes. This review focuses on molecular taxonomic advances in the cultivated red algae with the highest commercial value globally: Eucheuma and Kappaphycus, Porphyra sensu lato and Gracilaria. All three groups are similarly taxonomically challenging: speciose, morphologically plastic, with poorly resolved species boundaries. Eucheuma and Kappaphycus are frequently misidentified and the molecular markers cox2-3 spacer, cox1 and RuBisCO spacer have helped in understanding phylogenetic relationships and identifying new species and haplotypes. In Porphyra sensu lato (Bangiales) species identification and phylogenetic relationships were highly problematic until a taxonomic revision based on a two-gene phylogeny (18S and rbcL) resulted in nine genera of bladed species. Pyropia, with at least 89 species, three in nori cultivation, has potential for new commercial evaluation. In Gracilaria sensu lato, earlier efforts to resolve species-level taxonomy and generic descriptions were superseded by application of molecular tools, including DNA sequences of the RuBisCO spacer, rbcL gene, 18S and the ITS region. Studies of these cultivated red algal genera highlight the need for a robust taxonomy, a more standardized approach to the molecular markers used and a comprehensive dataset for each representative species. Current work on DNA-based species delimitation, the emergence of high throughput sequencing, multi-gene phylogenies, publication of whole genomes (e.g. Porphyra umbilicalis) and genomes in the pipeline (e.g. Gracilaria) are increasingly improving our understanding of phylogenomic relationships and species relationships. This knowledge, in turn, can then be applied to improving red seaweed aquaculture.

Phylogeography of Hydropuntia cornea/Hydropuntia usneoides complex (Gracilariales, Rhodophyta) in the Yucatan Peninsula

:Phylogeographic studies can contribute to our understanding of the evolutionary forces acting on the patterns of genetic variation and the evolutionary history of species. The Hydropuntia cornea/Hydropuntia usneoides species complex consists of two common species of red algae in the Gulf of Mexico and Caribbean Sea. Both species exhibit high phenotypic plasticity and total overlap in morphological characters and are only distinguished genetically (group GI, assigned to H. usneoides and group GII, assigned to H. cornea). In the Yucatan Peninsula, where they are abundant, they have a sympatric distribution. In order to understand the historical events and their influence on the current distribution patterns of these species around the Yucatan Peninsula and compare them with some populations from Venezuela and Brazil, we analyzed variation in the plastid-encoded RuBisCo spacer. A total of 133 individuals collected from 14 sites were sequenced. The analyses revealed 12 haplotypes (R1–R12). The haplotype network revealed two major groups (GI and GII) separated by three mutational steps. Group I was found in almost all sampled sites (n = 13), while GII was found in six sites but was absent from the Gulf of Mexico (Campeche). Haplotype R1 was the most abundant in GI, and haplotype R4 was dominant in GII. Genetic variation was higher in GI than in GII. Mismatch distribution suggests that GI may be in a period of demographic equilibrium, and GII experienced a recent demographic expansion and may have come from the south when the northern portion of the peninsula emerged (2.8 million years ago). Our results revealed that the Yucatan Peninsula is a mix of southern and northern floristic influences, which can be explained by the geological events in the area.

Analysis of the complete plastomes of three species of Membranoptera (Ceramiales, Rhodophyta) from Pacific North America.

Next generation sequence data were generated and used to assemble the complete plastomes of the holotype of Membranoptera weeksiae, the neotype (designated here) of M.tenuis, and a specimen examined by Kylin in making the new combination M.platyphylla. The three plastomes were similar in gene content and length and showed high gene synteny to Calliarthron, Grateloupia, Sporolithon, and Vertebrata. Sequence variation in the plastome coding regions were 0.89% between M.weeksiae and M.tenuis, 5.14% between M.weeksiae and M.platyphylla, and 5.18% between M.tenuis and M.platyphylla. We were unable to decipher the complete mitogenomes of the three species due to low coverage and structural problems; however, we assembled and analyzed, the cytochrome oxidase I, II, and III loci and found that M.weeksiae and M.tenuis differed in sequence by 1.3%, M.weeksiae and M.platyphylla by 8.4%, and M.tenuis and M.platyphylla by 8.1%. Evaluation of standard marker genes indicated that sequences from the rbcL, RuBisCO spacer, and CO1 genes closely approximated the pair-wise genetic distances observed between the plastomes of the three species of Membranoptera. A phylogenetic tree based on rbcL sequences showed that M.tenuis and M.weeksiae were sister taxa. Short rbcL sequences were obtained from type specimens of M.dimorpha, M.multiramosa, and M.edentata and confirmed their conspecificity with M.platyphylla. The data support the recognition of three species of Membranoptera occurring south of Alaska: M.platyphylla, M.tenuis, and M.weeksiae.

Cryptic diversity of the mangrove-associated alga Bostrychia (Rhodomelaceae, Rhodophyta) from Thailand

Abstract Algal diversity has been extensively investigated using combinations of morphological and molecular approaches. These combined approaches are especially relevant for organisms where cryptic species are known to exist. Bostrychia is a widely distributed red alga commonly associated with mangroves and often exhibits cryptic diversity. Most previous studies of diversity of Bostrychia in Thailand were based solely on morphological identifications. Distribution based on morphospecies may not reveal the same phylogeographic patterns that are identifiable with genetic data. In the present study, we employed RuBisCo spacer sequences to observe patterns of genetic diversity of Bostrychia species along the coasts of the Andaman Sea (Indian Ocean) and Gulf of Thailand (Pacific Ocean) in Thailand. Our results show that, of the eight morphospecies of Bostrychia recognized on both coasts of Thailand, four (B. binderi, B. calliptera, B. tenella and B. moritziana) consist of multiple cryptic species. We found different distribution patterns for two cryptic species of B. binderi, one restricted to the Gulf of Thailand and the other to the Andaman Sea. Several new haplotypes were discovered for B. binderi, B. tenella and the B. moritziana/B. radicans species complex, which are mostly distributed along separate coasts of Thailand. Only through the use of molecular data were we able to determine differences in the distribution of cryptic Bostrychia species along the two coasts. These results highlight the importance of molecular data for red algal species distribution studies and also reinforce the differences between the two sides of the Thai-Malay peninsula.

Phylogeography of the Lessonia variegata species complex (Phaeophyceae, Laminariales) in New Zealand

A goal of phylogeography is to relate phylogenetic patterns to potential historic and contemporary geographic isolating events. Genetic breaks found in phylogeographic studies may denote boundaries between more generally applicable biogeographic regions. We investigated the distribution of Lessonia variegata, an important habitat forming alga, found on most rocky shores around New Zealand’s main islands, plus related species from surrounding waters. L. variegata has been shown to consist of four distinct cryptic species. Our aim was to compare the distribution of L. variegata with proposed bioregions; and to develop phylogeographic hypotheses to explain its present day distribution. Both a mitochondrial (atp8-sp) and plastid (RuBisCo spacer) marker, with different mutation rates, were used to gain information of the phylogenetic history of Lessonia. The data revealed high phylogeographic structuring and reciprocal endemism for all L. variegata cryptic species. One species (L. variegata / N) is confined to the northern part of the North Island of New Zealand; L. variegata / W is found at the southeast of the North Island and the northern South Island; L. variegata / K is endemic to the northeast South Island; and L. variegata / S is restricted to the southern part of the South Island. No overlapping areas of L. variegata species distribution were found. The data showed that genetic breaks in Lessonia do mostly correlate to bioregions, and highlight the importance of Cape Campbell at the northeast of the South Island and East Cape in the North Island, well known phylogeographic breaks, as a barrier between adjacent species. Key words: bioregions; Chatham Islands; Lessonia; mitochondrial marker; Phaeophyceae; plastid marker; Subantarctic islands

Morphological and Molecular Studies of Undescribed <i>Kappaphycus</i> Species

Morphological and molecular studies were carried on an undescribed species of Kappaphycus (AS 12) from Sabah, Malaysia. The species displays unique and different physical characters from Kappaphycus alvarezii , K. striatus , K. malesianus and Eucheuma denticulatum in terms of branching patterns, thalli texture and colors. The phylogenetic position of this plant was inferred by cox 2-3 spacer, intergenic transcribed spacer (ITS) region and RuBisCo spacer. Based on the results from this study, it is clear that the specimen AS 12 pointed to significant differences from K. alvarezii , K. striatus , K. malesianus and E. denticulatum as supported by both morphological and molecular analyses.