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Understanding our biodiversity is of the utmost importance to determine evolutionary histories of organisms, reliably detect new incursions and select species for commercial operations. Advances in molecular techniques have provided a strong tool to facilitate a deeper understanding of our biodiversity. Macroalgae are a polyphyletic group that comprises three phyla: Chlorophyta (green algae), Ochrophyta (brown algae) and Rhodophyta (red algae). These three algal groups have complex evolutionary histories, play essential roles in our ecosystem, and provide a diverse range of commercial products (e.g. food) and services (e.g. bioremediation). New Zealand is known for its high and unique biodiversity, including macroalgae. Here, we compared all named macroalgal species to publicly available DNA sequence data in the NCBI database (GenBank) with the aim to assess the number of sequenced species and determine which groups require more work. Our review revealed that the majority of named macroalgal species in New Zealand have been either not sequenced or have not been sequenced from New Zealand specimens. Furthermore, the majority of sequenced species have fewer than 10 sequences publicly available. This lack of DNA sequence data dramatically impacts our understanding of our biodiversity, the detection of new incursions, and hinders the utilisation of our unique diversity commercially to its highest potential. [ABSTRACT FROM AUTHOR]

Members of the red algal order Bangiales are morphologically simple, with the gametophyte generation consisting of either filaments or blades, and the sporophyte generation consisting of microscopic uniseriate branched filaments. An ancient lineage, the order is distributed worldwide. The foliose species are the basis for the most valued seaweed aquaculture crop globally. In New Zealand, foliose species are known as karengo (parengo), and are highly prized by Māori. Phylogenetic analyses presented here highlight the great diversity of both species and genera in New Zealand with at least 47 species present in five filamentous genera (three undescribed, and two endemic and monotypic – Dione and Minerva), and four foliose genera (Clymene, Porphyra, Pyropia, and Lysithea). Based on the data available to date, it is likely that there are more undiscovered species. The diversity of New Zealand taxa is spread throughout the evolutionary lineages of the Bangiales. It is likely that members of this order have been on New Zealand shores prior to the breakup of Gondwana. Our analyses point to strong affinities of the New Zealand foliose species with other southern hemisphere regions. While international research on life history and reproductive modes in members of the Bangiales has revealed an extraordinary range of asexual, sexual and vegetative reproductive modes in both gametophyte and sporophyte stages, life history complexity and the genetic and ecological consequences have not been investigated for New Zealand species. While foliose Bangiales have special status in New Zealand as taonga species, little is understood about their vulnerability to human-mediated environmental changes, how changing climate may influence phenology of reproduction, and whether there are differential impacts on survival of gametophytes and sporophytes. Greater understanding of the biology, ecology and reproduction of Bangiales is critical for future resource management and conservation of genetic diversity. [ABSTRACT FROM AUTHOR]

New Zealand's algal flora is still far from fully explored, and new taxa continue to be discovered. The taxonomy of the red algal order Hildenbrandiales, consisting mostly of crustose members, is controversial as descriptions are largely based on limited morphological features. The order Hildenbrandiales is also in a close, apparently obligate, relationship with an endophytic fungus. Apophlaea is a genus in this order currently comprising two described species, both endemic to New Zealand. The morphology of this genus is more complex than that of other members of the Hildenbrandiales as it consists of extensive upright thalli. Sampling of Apophlaea in New Zealand, especially in the southern part of the North Island, has led to the discovery of a genetically distinct entity, that is only crustose. We propose a new species for this entity, Apophlaea darchinoae sp. nov., which is found on rocks in the high intertidal zone. This species has the typical tetrasporangial conceptacles of Apophlaea and no other reproductive structures were observed, and it consists of filaments that are laterally joined by secondary pit connections. Apophlaea darchinoae can be found in sympatry with A. sinclairii in the north of the North Island. We provide molecular evidence for the distinct nature of A. darchinoae and provide observations of extensive fungal filaments within this new species. [ABSTRACT FROM AUTHOR]

Collectively known as eucheumatoids, Eucheuma denticulatum, Kappaphycus alvarezii, K. malesianus, and K. striatus are the main farmed seaweed species in the Philippines. The success of seaweed farming for over five decades in the country is due, in part, to the high diversity of cultivars maintained by the Filipino farmers. Notwithstanding the fact that many eucheumatoid cultivars are presently (and consistently) recognized by the Filipino farmers, there has been no attempt to summarize the current state of the local traditional knowledge about the diversity of this seaweed group, especially with reference to the taxonomy, cultivar designation and distribution. Factors based on present day local knowledge on the eucheumatoid cultivars and what is known on genetic identification in the Philippines were also discussed. A total of 66 cultivars recognized across 58 provinces in the Philippines were documented. Most of these cultivars were morphologically identified as either K. alvarezii or K. striatus, however, the majority were yet to be genetically identified. In part, due to higher demand of kappa-carrageenan extract as compared from the iota type, K. alvarezii and K. striatus were widely cultivated in the Philippines than that of E. denticulatum. Only in the southern Philippines that K. malesianus is currently cultivated. The diverse cultivars identified in this study suggest that the Filipino farmers possess important traditional knowledge that can be useful for future crop selection and breeding. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) signalling has a multitude of roles in cellular processes throughout biology. We hypothesized that red algal fertilization may offer an interesting model to study ROS-mediated signalling, as the stages of fertilization are complex and unique. We detected the localization of ROS production microscopically and monitored the expression of three homologues of NADPH oxidase in reproductive cells during fertilization. ROS were instantaneously produced by spermatia (sperm) when they attached to female trichogynes, diffused across the cell membrane in the form of H2O2, and triggered ROS generation in the carpogonium (egg) as well as carpogonial branch cells which are not in direct contact with spermatia. The expression of NADPH oxidase homologues, RESPIRATORY BURST OXIDASE HOMOLOGUES (BmRBOH s), began to be up-regulated in the female plant upon gamete binding, peaking during the fertilization process and descending back to their original level after fertilization. Pre-treatment with diphenylene iodonium or caffeine blocked gene expression as well as H2O2 production. Post-fertilization development was also inhibited when the redox state of the plants was perturbed with H2O2 at any time before or after the fertilization. Our results suggest that H2O2 acts as an auto-propagating signalling molecule, possibly through Ca2+ channel activation, and regulates gene expression in fertilization as well as post-fertilization development in red algae. [ABSTRACT FROM AUTHOR]

Marine phylogeographic studies have recently shown that historical events, oceanography and ecological factors shape patterns of biodiversity and population connectivity. In southeastern Australia a historical geographic barrier, the Bassian Isthmus, results in deep genetic differentiation between some marine taxa. Using partial mitochondrial cytochrome oxidase subunit I (COI) DNA sequences, we investigated the genetic diversity and phylogeography among 26 populations of the red alga Bostrychia intricata along the southeastern Australian coast. Our genetic data revealed the occurrence of five cryptic B. intricata species (lineages N5, N7, N8, N9 and N10), two of which (N9 and N10) are newly discovered and endemic to Tasmania, while cryptic species N5 and N7 were confined to mainland Australia. Species N8 was more genetically diverse and extensively distributed than the other cryptic species, because it occurred both on mainland Australia and in Tasmania. We also detected a clear east–west phylogeographic break between cryptic species N7 and N5, and between haplotypes of species N8 on either side of Wilsons Promontory (the southernmost tip of mainland Australia). Spatial analysis of molecular variance identified three clusters of populations of species N8 along the south coast of Australia, and the split among these groups corresponded to extensive sandy areas: Coorong dunefield and Ninety Mile Beach. Additionally, our study detected the separation between mainland Australian (species N5 and N7) and Tasmanian species (N9 and N10) across the Bass Strait. We suggest that phylogeographic breaks and genetic differentiation in cryptic B. intricata species likely correlate to the historical Bassian land bridge, present-day habitats and different oceanographic circulation patterns. [ABSTRACT FROM AUTHOR]