Journal of Phycology最新文献_第5页

Dinoflagellate responses to nutrients and mangrove leaf organic matter in the bioluminescent Mangrove Lagoon, St. Croix, U.S. Virgin Islands 美属维尔京群岛圣克罗伊岛生物发光红树林泻湖中鞭毛藻对营养物和红树林叶片有机质的响应。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-17 DOI: 10.1111/jpy.70189

James L. Pinckney, Michelle Zimberlin, Dianne I. Greenfield

{"title":"Dinoflagellate responses to nutrients and mangrove leaf organic matter in the bioluminescent Mangrove Lagoon, St. Croix, U.S. Virgin Islands","authors":"James L. Pinckney, Michelle Zimberlin, Dianne I. Greenfield","doi":"10.1111/jpy.70189","DOIUrl":"10.1111/jpy.70189","url":null,"abstract":"Bioluminescent bays (biobays) are uncommon coastal ecosystems featuring dense populations of dinoflagellates, often found in mangrove-ringed lagoons with long water retention times and high organic matter (OM) levels. Although mangroves are associated with high dinoflagellate abundance, it remains uncertain how inorganic nutrients compare with mangrove-derived organic matter in shaping phytoplankton communities. We performed short-term in situ bioassays in Mangrove Lagoon, St. Croix, U.S. Virgin Islands, to compare phytoplankton community responses to additions of inorganic nutrients (N and P) and senescent mangrove leaf additions. Phytoplankton composition was assessed using high-performance liquid chromatography (HPLC) pigment analysis combined with CHEMTAX, and data were analyzed with compositional and centered log-ratio principal component analyses (CLR–PCAs). Nutrient additions primarily increased total phytoplankton biomass and favored diatom-dominated communities, consistent with N limitation, but did not significantly alter community composition. Conversely, adding senescent mangrove leaves consistently shifted the community toward higher abundances of peridinin-containing dinoflagellates, without significantly increasing the abundance of other phytoplankton groups. Multivariate analysis showed that leaf additions shifted the community along a continuous compositional spectrum rather than creating distinct assemblages. These findings suggest that OM (leachate) from senescent mangrove leaves, rather than inorganic N and P enrichment alone, is a plausible mechanism for promoting dinoflagellate dominance in Mangrove Lagoon. Our results underscore the potential role of mangrove OM input in sustaining dinoflagellate-dominated environments in some tropical lagoons, demonstrating a mechanism by which mangroves may regulate phytoplankton community composition in adjacent waters.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1240-1250"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.70189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148264903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Klebsormidiophyceae sister genomes reveal multicellularity and stress adaptations Klebsormidiophyceae姐妹基因组揭示了多细胞和应激适应。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-23 DOI: 10.1111/jpy.70199

Jianchao Ma, Rui Huo, Shenglong Bai, Jinling Huang

{"title":"Klebsormidiophyceae sister genomes reveal multicellularity and stress adaptations","authors":"Jianchao Ma, Rui Huo, Shenglong Bai, Jinling Huang","doi":"10.1111/jpy.70199","DOIUrl":"10.1111/jpy.70199","url":null,"abstract":"Klebsormidium and Interfilum are two closely related genera in the charophyte group Klebsormidiophyceae. Members of Klebsormidium are usually multicellular whereas those of Interfilum are unicellular. The genome of K. nitens has been sequenced using second-generation sequencing technology, but the assembled scaffolds are frequently fragmented. In this study, we re-sequenced the genomes of K. nitens using PacBio platform and obtained 15.8 Gb long reads. We also sequenced the genome of I. paradoxum and obtained 13 Gb long reads. The I. paradoxum genome assembly (81.7 Mb) included 59 contigs with N50 of 1.9 Mb, and the K. nitens assembly (132.9 Mb) included 188 contigs with N50 of 2.1 Mb. A total of 20,425 and 15,103 protein-coding genes were annotated in K. nitens and I. paradoxum, respectively. Comparative genome analyses identified 2805 gene families specific to Klebsormidiophyceae, which are enriched in gene ontology (GO) categories related to jasmonic acid (JA) biosynthesis and rRNA catabolism. Twenty-seven gene families, enriched in RNA–DNA hybrid ribonuclease activity and transmitter-gated ion channel activity, were found to have expanded in the last common ancestor of I. paradoxum and K. nitens. Several genes related to cell wall structure, including galactosyltransferase (GALT), were absent in I. paradoxum. We also found that approximately 50% of abiotic stress-related genes (e.g., late embryogenesis abundant, LEA genes) are present in land plants. The generation of K. nitens and I. paradoxum genomes and transcriptome data provides additional resources to understand the origin and evolution of land plants.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1251-1263"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148302195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spore priming by coastal upwelling in the intertidal kelp Lessonia spicata 潮间带海带沿岸上升流对孢子的激发作用。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-27 DOI: 10.1111/jpy.70200

Gloria M. Parada, Enrique A. Martinez Mosqueira, Bernardo R. Broitman

{"title":"Spore priming by coastal upwelling in the intertidal kelp Lessonia spicata","authors":"Gloria M. Parada, Enrique A. Martinez Mosqueira, Bernardo R. Broitman","doi":"10.1111/jpy.70200","DOIUrl":"10.1111/jpy.70200","url":null,"abstract":"The kelp populations of two cryptic species of Lessonia inhabiting the intertidal zone of the southeastern Pacific are vulnerable to local extinction and range contraction by being exposed to large-scale thermal extremes and strong harvesting by artisanal fisheries. Our study explored the effect of variable ocean temperature conditions on the germination of spores, a critical stage for post-disturbance persistence of local populations, including harvesting. Over a 15-month experimental period, we collected reproductive tissues from 10 tagged sporophytes of a wild local population of L. spicata in Central Chile (~33.5° S) and measured germination success. Reproductive activity closely tracked the presence of low (<14°C) ocean temperatures at the study site. Mean spore germination was over 80% from late Austral fall to late spring and sharply declined and became more variable under the warmer ocean conditions of summer and early fall. Unexpectedly, a mid-summer mesoscale upwelling event cooled seawater below 14°C, and spore germination success increased from <50% to up to 90%. Across the study period, germination showed a significant negative correlation with seawater temperature, down to a lag of 4 days prior to the collection of reproductive tissue. These results suggest both a temperature threshold and a temporal scale for spore priming in L. spicata, providing support to earlier hypotheses positing spatial heterogeneity in the upwelling regime as the leading driver of speciation in the Lessonia complex. Together, our results provide an important evolutionary insight for the conservation, restocking, and management of the Lessonia complex.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1383-1391"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148339081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mysticladia gen. nov. (Cladophorales, Ulvophyceae): A new genus encompassing two long-recognized Cladophora species from the South Atlantic Ocean 神秘藻属gen. 11 . (Cladophorales, Ulvophyceae)：一个新属，包括来自南大西洋的两个长期认识的Cladophora物种。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-07-03 DOI: 10.1111/jpy.70194

Jhullyrson Osman Ferreira de Brito, Victor Andrei Rodrigues Carneiro, Valéria Cassano, Daniele Mendes da Silva, Carlos Wallace Nascimento Moura, Watson Arantes Gama

{"title":"Mysticladia gen. nov. (Cladophorales, Ulvophyceae): A new genus encompassing two long-recognized Cladophora species from the South Atlantic Ocean","authors":"Jhullyrson Osman Ferreira de Brito, Victor Andrei Rodrigues Carneiro, Valéria Cassano, Daniele Mendes da Silva, Carlos Wallace Nascimento Moura, Watson Arantes Gama","doi":"10.1111/jpy.70194","DOIUrl":"10.1111/jpy.70194","url":null,"abstract":"The genus Cladophora (Cladophorales, Ulvophyceae) has a long history of taxonomic challenges due to morphological plasticity and incongruence between traditional classifications and molecular phylogenies. Here, we propose Mysticladia gen. nov. to accommodate species previously assigned to Cladophora but phylogenetically placed within the Siphonocladus clade. Analyses of concatenated SSU + LSU rDNA gene sequences from specimens collected along the Brazilian coast revealed that populations morphologically identified as C. prolifera and C. aokii form a distinct and phylogenetically distant clade from Cladophora sensu stricto. Genetic divergence and morphological comparisons supported the recognition of two new cryptic species: Mysticladia nigra sp. nov. and M. edisonii sp. nov. Both seemingly restricted to the southwestern Atlantic. These species are morphologically indistinguishable from their closest relatives but distinguishable by DNA sequences. Additionally, we transfer C. prolifera, C. aokii, and C. coelothrix to Mysticladia. Our findings broaden the widespread cryptic diversity within the Cladophorales and emphasize the critical need for molecular analyses across populations in this group, including those already and correctly identified based on morphology alone. Such efforts are essential for elucidating cryptic lineages and species boundaries in simple filamentous green algae, where phenotypic plasticity often disguises true evolutionary relationships.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1204-1220"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148382272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ariadnema polymorpha gen. et sp. nov. (Scytonemataceae, Cyanobacteria): A new heterocytous cyanobacterium with true and false branching from ruins in the Brazilian Atlantic Forest. （蓝藻科）：巴西大西洋森林废墟中一种具有真假分支的异细胞蓝藻。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 DOI: 10.1111/jpy.70225

Jefferson Vitor Melo Cabral, Haywood Dail Laughinghouse, Jonatas Mota Paulino, Watson Arantes Gama

{"title":"Ariadnema polymorpha gen. et sp. nov. (Scytonemataceae, Cyanobacteria): A new heterocytous cyanobacterium with true and false branching from ruins in the Brazilian Atlantic Forest.","authors":"Jefferson Vitor Melo Cabral, Haywood Dail Laughinghouse, Jonatas Mota Paulino, Watson Arantes Gama","doi":"10.1111/jpy.70225","DOIUrl":"https://doi.org/10.1111/jpy.70225","url":null,"abstract":"A novel heterocytous Cyanobacterium, Ariadnema polymorpha gen. et sp. nov., was observed in the northern Brazilian Atlantic Forest (BAF), a globally significant biodiversity hotspot that has microbiome diversity yet to be explored. Isolated from ancient sugarcane mill ruins within the BAF, the new genus (strain CCAPE130) exhibits a unique morphology, including inverted Y true branching, coupled with scytonematoid and tolypothricoid false branching within the same trichome, an unusual morphology among heterocytous cyanobacteria. A polyphasic taxonomic approach, integrating detailed morphological characterization, transmission electron microscopy (TEM) ultrastructure analysis, 16S rRNA gene sequencing, and 16S-23S ITS rRNA region sequencing, was employed. Phylogenetic analysis using maximum likelihood and Bayesian inference placed CCAPE130 as a sister clade to the Symphyonema and Mastigocladopsis genera, which were previously associated with Symphyonemataceae, a family originally diagnosed by true Y-branching but now merged into the false-branched family Scytonemataceae. Structural comparisons of the 16S-23S ITS rRNA region D1-D1' showed variations, and the Box B region exhibited structural similarities with related lineages despite nucleotide differences. This research represents a phylogenetic analysis of Scytonemataceae specimens with true and false branching from the Americas, validating A. polymorpha as a new genus and species. Our results significantly enhance our understanding of Scytonemataceae phylogeny and underscore the rich, often overlooked, cyanobacterial diversity present in tropical forest regions, such as the Brazilian Atlantic Forest.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimizing a long-term monitoring strategy to track emerging cyanobacterial blooms in a Great Lakes estuary 优化长期监测战略，跟踪新兴的蓝藻华在五大湖河口。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-08-07 DOI: 10.1111/jpy.70215

Peter A. Birschbach, Euan D. Reavie, Christopher T. Filstrup, Hannah Nicklay

{"title":"Optimizing a long-term monitoring strategy to track emerging cyanobacterial blooms in a Great Lakes estuary","authors":"Peter A. Birschbach, Euan D. Reavie, Christopher T. Filstrup, Hannah Nicklay","doi":"10.1111/jpy.70215","DOIUrl":"10.1111/jpy.70215","url":null,"abstract":"Cyanobacterial harmful algal blooms (cHABs) are increasingly frequent and severe globally. Recently, the St. Louis River Estuary (SLRE) has experienced numerous cHABs, but the locations, timing, and environmental conditions associated with them are unknown. We first investigated environmental predictors of cyanobacteria through a multifaceted approach, highlighting key relationships to understand past cHABs, and then performed a detailed spatiotemporal redundancy analysis of sampling data to optimize site selection and sampling frequency for future monitoring. We employed an oversampling approach over 2 years at eight spatially heterogeneous stations. Random forest analysis paired with constrained ordination indicated that warm, late-summer temperatures were an important predictor of cyanobacterial abundance (biovolume), and drought-mediated stoichiometric nitrogen limitation may have facilitated dominance by diazotrophic cyanobacteria in 2023. Temporal redundancy analysis revealed no ideal sampling frequency, but late summer, weekly sampling, and as-needed bloom response collections were deemed critical for tracking cHABs. A 30- to 40-day lag effect between water temperature and cyanobacterial abundance suggested temperature as an early warning predictor of summer bloom intensity. Water quality was more spatially heterogeneous than phytoplankton communities, informing future monitoring site selection designed to comprehensively capture water quality variability and minimize phytoplankton community redundancy while prioritizing sites with past blooms. Our findings inform an optimized monitoring program for the SLRE and demonstrate a feasible monitoring optimization approach that could be developed and applied elsewhere to track risks from cHABs and other stressors.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1264-1296"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.70215","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148684686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seaweed community dynamics on the Konkan coast: Implications of variation in environmental factors 康坎海岸海藻群落动态：环境因子变化的含义。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-01 DOI: 10.1111/jpy.70186

Temjensangba Imchen, Krishna P. Akshay

{"title":"Seaweed community dynamics on the Konkan coast: Implications of variation in environmental factors","authors":"Temjensangba Imchen, Krishna P. Akshay","doi":"10.1111/jpy.70186","DOIUrl":"10.1111/jpy.70186","url":null,"abstract":"This study investigated seaweed diversity across 21 rocky intertidal sites along the Konkan coast, on the west coast of India. A total of 107 species were documented; Rhodophyta (red algae) were the most dominant (43.9%), followed by Chlorophyta (green algae, 29%) and Phaeophyceae (brown algae, 27.1%). High species diversity (H′) and even distribution were observed at the Alibaug-Murud and Sandkhol stations. Specifically, Sandkhol hosted the highest richness of Phaeophyceae (15 species), whereas Kunkeshwar exhibited the highest Rhodophyta richness (24 species). The greatest Chlorophyta richness (12 species) was recorded at Anjuna, Kunkeshwar, and Alibaug-Murud. Environmental factors, including salinity, pH, light intensity, and nutrients showed significant spatio-seasonal variations (p < 0.01). Nutrient-rich conditions were observed to promote the growth of opportunistic, fast-growing species, which may outcompete and inhibit slower growing taxa, thereby altering overall diversity. Salinity and nutrient levels emerged as the predominant variables correlated with community structure. Notably, ~71% of species were common to both pre-monsoon and post-monsoon seasons. Furthermore, this study indicates that increased variability in factors such as nutrients may promote the dominance of opportunistic macroalgae.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1147-1168"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heat stress induces organelle alterations in Macrocystis pyrifera gametophytes 热胁迫诱导大孢子虫配子体细胞器的改变。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-18 DOI: 10.1111/jpy.70196

Maddelyn Harden, David S. Koos, Karina Arzuyan, Maxim Kovalev, Rusty Lansford, Filipe Alberto, Sergey Nuzhdin

{"title":"Heat stress induces organelle alterations in Macrocystis pyrifera gametophytes","authors":"Maddelyn Harden, David S. Koos, Karina Arzuyan, Maxim Kovalev, Rusty Lansford, Filipe Alberto, Sergey Nuzhdin","doi":"10.1111/jpy.70196","DOIUrl":"10.1111/jpy.70196","url":null,"abstract":"Kelp, brown macroalgae in the order Laminariales, provide ecosystem services vital to ocean biodiversity. However, kelp forests worldwide are declining due to abiotic stressors such as ocean warming. In this study, we present results from high-resolution confocal microscopy and in vivo imaging system imaging using protocols developed to visualize kelp gametophyte cells exposed to heat-stress treatments. Imaging revealed chloroplast mislocalization, fragmentation, and subsequent loss of chloroplasts in heat-stressed gametophyte cells. Additionally, nuclei exhibited fragmentation and a progressive loss of fluorescent signal, and the associated microbiome proliferated under various heat-stress treatments. Notably, because brown algae possess a continuous outer membrane that connects the nuclear envelope and the chloroplast envelope, these observations suggest a cellular vulnerability underlying thermal sensitivity in brown macroalgae. Finally, by comparing heat-stress tolerant and heat-stress sensitive genotypes, we found that genotypes with higher heat tolerance exhibited substantially fewer abnormalities compared to sensitive ones.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1129-1146"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.70196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148271871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The evolutionary ecology of reproduction in the red alga Palmaria palmata: Insights from an atypical life cycle 红藻繁殖的进化生态学：来自非典型生命周期的见解。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-23 DOI: 10.1111/jpy.70193

Aurélien Baud, Myriam Valero, Stéphane Mauger, Stacy A. Krueger-Hadfield, Philippe Potin, Christophe Destombe

{"title":"The evolutionary ecology of reproduction in the red alga Palmaria palmata: Insights from an atypical life cycle","authors":"Aurélien Baud, Myriam Valero, Stéphane Mauger, Stacy A. Krueger-Hadfield, Philippe Potin, Christophe Destombe","doi":"10.1111/jpy.70193","DOIUrl":"10.1111/jpy.70193","url":null,"abstract":"Unlike other red algae, the perennial species Palmaria palmata exhibits pronounced sexual dimorphism with a microscopic female gametophytic phase that does not produce cystocarps. To investigate how these unique features of its life cycle influence its reproductive mode, we analyzed the relative proportion of macroscopic individuals (tetrasporophytes vs. male gametophytes) across multiple geographic scales and between intertidal and subtidal habitats along the western coast of France (892 individuals collected from 17 locations). Because female gametophytes are microscopic and cannot be directly sampled in the field, their frequencies were inferred under two alternative hypotheses: (H1) assuming an equal sex ratio (i.e., the proportion of females equal to males) and (H2) assuming the proportion of females equals tetrasporophytes, given that tetrasporophytes develop directly on a female gametophyte. Under H1, our results predict a demographic advantage of tetrasporophytes over gametophytes. Moreover, tetrasporophytes were significantly more abundant in intertidal than in subtidal zones, likely reflecting their greater resilience to environmental fluctuations. Conversely, under H2, the sex ratio was significantly biased toward female gametophytes and the estimated proportion of tetrasporophytes was lower than that of gametophytes. In addition, the relative contribution of self-fertilization and clonal reproduction were assessed using 11 microsatellite markers. These findings confirm that this species reproduces mainly sexually and suggest that sexual dimorphism may limit selfing and enhance the survival of the tetrasporophyte, which develops directly on the female, thereby compensating for the absence of cystocarps. Overall, our results provide valuable insights into the reproductive strategies and adaptive potential of this commercially important alga.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1327-1343"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148301518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of the invasive diatom species Cymbella janischii on riverine microbial biofilm communities and a potential role of bacterially produced zeatin 入侵硅藻Cymbella janischii对河流微生物生物膜群落的影响及细菌产生的玉米素的潜在作用。

IF 4.3 3区生物学

Journal of Phycology Pub Date : 2026-08-18 Epub Date: 2026-06-30 DOI: 10.1111/jpy.70195

Eldrin D. L. R. Arguelles, Kana Mugikura, Shinya Sato

{"title":"Impact of the invasive diatom species Cymbella janischii on riverine microbial biofilm communities and a potential role of bacterially produced zeatin","authors":"Eldrin D. L. R. Arguelles, Kana Mugikura, Shinya Sato","doi":"10.1111/jpy.70195","DOIUrl":"10.1111/jpy.70195","url":null,"abstract":"The diatom Cymbella janischii is an invasive species in Japan, causing nuisance blooms by forming thick mats in rivers. To date, there are no documented studies on the microbiome associations in C. janischii mats or the processes that drive bloom formation. This study used metabarcoding of diatoms, bacteria, and fungi to identify key species and assess the effects of C. janischii blooms on the benthic microbial communities. C. janischii blooms reduced diatom and bacterial species diversity, while fungal diversity remained stable. In addition, the diatom Nitzschia paleacea and the bacterium Flavobacterium sp. were observed to co-occur and vary in abundance, indicating a possible ecological link that may affect mat structure or function. Metagenomic predictions of bacterial functions showed that compared to benthic stones without visible C. janischii mats, mat-associated bacteria had enriched pathways related to the metabolism of carbohydrates, nucleotides, and amino acids, along with zeatin biosynthesis. Zeatin is a cytokinin phytohormone that stimulates plant growth and development. In vitro exposure of C. janischii to varying zeatin concentrations confirmed its growth-promoting effects, inducing cell proliferation and stalk formation. This study shows that zeatin stimulates the growth of C. janischii. The findings of this study provide new insights into microbiome diversity, identifying key taxa associated with C. janischii mats to help better understand bloom formation.","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"62 4","pages":"1221-1239"},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.70195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148352249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0