American Journal of Botany最新文献

{"title":"Floral syndromes predict the most effective pollinators in five species of Salvia","authors":"Arturo Tavera,&nbsp;Martín H. de Santiago-Hernández,&nbsp;Víctor Rosas-Guerrero,&nbsp;Clementina González,&nbsp;Eduardo Cuevas","doi":"10.1002/ajb2.70067","DOIUrl":"10.1002/ajb2.70067","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Pollination syndromes are suites of floral traits associated with the most effective functional group of pollinators. Particular floral traits may not necessarily preclude visitation by different visitor guilds that could also contribute to plant reproduction. The genus <i>Salvia</i> comprises ca. 1000 species with floral traits almost exclusively associated with bee or hummingbird pollination syndromes. Nevertheless, the effectiveness of their floral visitors has rarely been evaluated. Here, the pollination effectiveness of floral visitors in five <i>Salvia</i> species was analyzed to assess the reliability of floral syndromes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The contribution to seed production of the most frequent floral visitors of <i>Salvia</i> species with melittophilous, ornithophilous, and mixed phenotypes was evaluated through single-visit experiments. In addition, the relationship between floral morphological traits and pollinator effectiveness was explored using principal component analysis to test the reliability of floral syndromes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Despite multiple floral visitor guilds to the plants, bees and hummingbirds were the most effective pollinators of plants with melittophilous and ornithophilous pollination syndrome, respectively. These two functional groups effectively pollinated the plant species with mixed floral traits. <i>Salvia</i> species pollinated by the same functional group were closer in the multivariate ordination space.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Even when floral syndromes precisely predict the most effective pollinators in <i>Salvia</i>, secondary pollinators also play a crucial role in plant sexual reproduction, especially for plant species with mixed floral phenotypes. This study highlights the importance of evaluating the effectiveness of floral visitors to assess the reliability of floral syndromes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Navigating the possibilities and pitfalls of biocrust recovery in a changing climate","authors":"Michala L. Phillips,&nbsp;Kristina E. Young,&nbsp;Cara Lauria,&nbsp;Sierra Jech,&nbsp;Ana Giraldo-Silva,&nbsp;Sasha C. Reed","doi":"10.1002/ajb2.70055","DOIUrl":"10.1002/ajb2.70055","url":null,"abstract":"<p>Biological soil crusts are complex communities composed of lichens, mosses, bacteria, and cyanobacteria that create a living skin on the soil surface across drylands worldwide. Although small in size, the vast area that biocrusts cover and the critical functions they provide make them a cornerstone of dryland health and resiliency. In addition to being important, biocrusts are exceptionally vulnerable to certain types of disturbance. Although they can withstand a wide range of temperatures and long periods without precipitation, biocrusts are highly sensitive to land-use change and are vulnerable to physical and compressional disturbance (i.e., trampling, vehicles, cattle, heavy machinery). In the face of these disturbances, a critical, long-standing question of interest to dryland ecologists is: Can biocrusts recover following disturbance without active intervention. If so, how long does it take? Early estimates of biocrust recovery suggested recovery can be incredibly slow (on the order of thousands of years), with more modern studies finding potential for faster recovery, especially with intervention. Multiple lines of evidence agree that recovery is context dependent, differing across climates, soils, and with the types of disturbance and biocrust. Additionally, active restoration of biocrusts is becoming more common as tractable strategies are developed for facilitating the establishment of biocrusts after disturbance. Here, we add to the body of knowledge about biocrust recovery following disturbances by reviewing recovery patterns, their connection to climate change, considerations for recovery in changing climates, and the role of restoration.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144332314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare species do not disproportionately contribute to phylogenetic diversity in a subalpine plant community","authors":"Leah N. Veldhuisen,&nbsp;Verónica Zepeda,&nbsp;Brian J. Enquist,&nbsp;Katrina M. Dlugosch","doi":"10.1002/ajb2.70061","DOIUrl":"10.1002/ajb2.70061","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Within plant communities, few species are abundant, and most are locally rare. Worldwide, 36% of plant species are exceedingly rare and often face high extinction risk. However, the community phylogenetic impact of the loss of rare plants is largely unknown in many systems. We address this gap by investigating how rare species contribute to phylogenetic diversity, considering multiple metrics of rarity and multiple elevations in a subalpine plant community.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We collected abundance data at three sites near the Rocky Mountain Biological Laboratory (Colorado, USA). We calculated each species' range size from public occurrence data. We calculated phylogenetic signal for abundance and range size, compared community phylogenetic metrics weighted by range size and abundance to unweighted metrics, and quantified the change in phylogenetic diversity when removing single species and groups of species ranked by rarity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found phylogenetic signal for abundance, but not range size. There was no difference between rarity-weighted and -unweighted phylogenetic diversity metrics. Finally, phylogenetic diversity did not decline more when we removed single rare species or groups of rare species than when we removed single common species and groups of common species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We found that rare species, whether at low abundance or with a small range, do not disproportionately contribute to phylogenetic diversity in our subalpine plant community. These results were consistent across elevations. Instead, rare species might provide phylogenetic redundancy with common species. Deeper understanding of functional differentiation is needed to understand contributions of rare species to this system.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70061","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144324179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare recombination in Salix nivalis and the maintenance of homomorphic sex chromosomes in willows","authors":"Ashmita Khanal,&nbsp;Nan Hu,&nbsp;Minghao Guo,&nbsp;Diksha Gambhir,&nbsp;Brian Sanderson,&nbsp;Matthew S. Olson","doi":"10.1002/ajb2.70059","DOIUrl":"10.1002/ajb2.70059","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Most dioecious angiosperms have homomorphic sex chromosomes, and non-recombining sex-linked regions (SLRs) likely comprise a small portion of the sex chromosome. The fountain of youth hypothesis posits that rare recombination within heterogametic SLRs may act to maintain homomorphy. Alternatively, turnovers of the sex-determining genes could also contribute to sex chromosome homomorphy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used reduced representation sequencing and mapping to the <i>Salix purpurea</i> reference genome to determine the size of the sex-linked region in three dwarf willows (<i>Salix phlebophylla</i>, <i>S. reticulata</i>, and <i>S. nivalis</i>). To test the fountain of youth hypotheses, we performed allelic state and linkage disequilibrium (LD) analyses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For all three species, sex-linked single nucleotide polymorphisms (SNPs) were identified on chromosome 15. Mean heterozygosity was higher in females, confirming that all three species were female heterogametic (ZW). A recombinant haplotype between the Z and W chromosomes was identified in <i>S. nivalis</i>, contributing to higher-than-expected mean heterozygosity in SLR and slow LD decay in males.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We propose that the uncommon ZW haplotype resulting from a recombination event identified here initiates the homogenization of Z and W chromosomes, leading to the maintenance of their homomorphy. Based on comparisons across all three SLRs, we further speculate that ongoing rare recombination events have influenced the shared patterns of sex-linked SNPs across <i>S. phlebophylla</i>, <i>S. reticulata</i>, and <i>S. nivalis</i> and is a process that influences sex chromosome evolution throughout the Salicaceae and flowering plants with homomorphic sex chromosomes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CRABS CLAW-independent floral nectary development in Penstemon barbatus","authors":"Amanda M. Katzer,&nbsp;Carolyn A. Wessinger,&nbsp;Brooklyn M. Anaya,&nbsp;Lena C. Hileman","doi":"10.1002/ajb2.70058","DOIUrl":"10.1002/ajb2.70058","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Plants secrete carbohydrate-rich nectar from specialized floral nectary glands to attract pollinators. <i>Arabidopsis</i> and <i>Petunia</i> (rosid and asterid core eudicots, respectively) share genetic control of nectary development requiring activation of <i>CRABS CLAW</i> by <i>euAGAMOUS</i> and <i>PLENA</i>. This module is conserved despite striking differences in nectary morphology between the two species. We tested whether the <i>euAGAMOUS/PLENA-CRABS CLAW</i> module likely extends to an asterid species with novel nectary morphology, <i>Penstemon barbatus</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To test conservation of the <i>euAGAMOUS/PLENA-CRABS CLAW</i> module and nectar sugar metabolism in <i>P. barbatus</i>, we carried out comparative transcriptomics, leveraging <i>Penstemon</i>'s unique nectary morphology. Specifically, lateral and ventral stamen filaments develop with and without nectaries at their base, respectively, allowing straightforward differential expression analyses to uncover nectary-specific gene expression.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Many genes were differentially expressed between nectary and non-nectary tissues, and pre- and post-nectar-removal. Differentially expressed genes pointed to key phloem, abaxial specification, and epidermal cell shape functions during nectary development. Differentially expressed genes pointed to regulation of sugar processing and secretion after nectary maturation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results suggest that <i>P. barbatus</i> nectaries develop independently of the canonical core-eudicot <i>CRABS CLAW</i> genetic module, despite being positioned within reproductive floral organ whorls, and that <i>P. barbatus</i> nectar production follows conserved sugar metabolic pathways.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70058","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-fire germination and plant invasion in Mediterranean Chile.","authors":"Korina Ocampo-Zuleta, Susana Paula, Juli G Pausas, Lohengrin A Cavieres, Ángela Sierra-Almeida, Susana Gómez-González","doi":"10.1002/ajb2.70057","DOIUrl":"https://doi.org/10.1002/ajb2.70057","url":null,"abstract":"<p><strong>Premise: </strong>Plants from regions where fire is a novel disturbance typically lack fire-adaptive traits, which may explain the post-fire invasion by alien plants from fire-prone ecosystems. Unlike many Mediterranean-type ecosystems, the Chilean matorral has a limited evolutionary history with fire. We predict that a negative germination response to fire will be more frequent in its native flora than in alien plants, most of which originate from the fire-prone Mediterranean Basin.</p><p><strong>Methods: </strong>We compiled a database on the germination responses to fire cues of 70 native and alien plant species from the Chilean matorral using published studies and unpublished data from our own experiments. We then compared the frequency of these responses between native and alien species using generalized linear mixed models.</p><p><strong>Results: </strong>Negative responses to heat shock were more probable in native than in alien species, while there were no differences in the probability of negative responses to smoke. Species origin did not affect the probability of positive responses to fire cues. When only annual plants were considered, natives and aliens did not differ in their germination responses to fire cues.</p><p><strong>Conclusions: </strong>Our findings suggest that the influence of post-fire germination on invasion processes in the Chilean matorral is better explained by the negative effects of heat on the germination of native species (which lack fire-adaptive traits) than by the positive response of alien species to fire cues. The reduced germination of natives creates opportunities for alien species establishment, rather than pre-existing fire adaptive traits driving invasion success.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70057"},"PeriodicalIF":2.4,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversification of the stem vascular system in a clade of recent radiation and multiple habit transitions: The Bunchosia clade (Malpighiaceae)","authors":"Angélica Quintanar-Castillo,&nbsp;Andre M. Amorim,&nbsp;Marcelo R. Pace","doi":"10.1002/ajb2.70056","DOIUrl":"10.1002/ajb2.70056","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Within the Malpighiaceae, the Bunchosia clade is distinctive for its significant habit variation and abundance of different vascular variants. However, the processes underlying the diversification of the vascular system over time and the ontogenetic events involved remain unclear. Focusing on the Bunchosia clade, this study explores how new vascular configurations evolve in Malpighiaceae and the factors driving this diversification.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We analyzed stem ontogeny in 19 species representing all six genera of the Bunchosia clade, sampling from the apex to the base of the plants. We used the phytools package in R to map the entire stem ontogenies onto the most recent phylogeny estimate of Malpighiaceae, identifying the developmental modifications and processes involved in stem diversification within the clade.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The ancestral condition of the clade was inferred to be a lianescent habit with regular stem anatomy. Over evolutionary time, two independent transitions to a self-supporting habit were inferred to have occurred. We identified five ontogenetic pathways, which led to distinct vascular system arrangements. Additionally, we propose two new records of cambial variants for the family.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>From a regular secondary growth condition, different vascular variants evolved in a short period of evolutionary time in this clade. The self-supporting habit appeared twice: (1) in <i>Bunchosia</i>, maintaining a plesiomorphic regular secondary growth, and (2) another in <i>Echinopterys</i>, where the self-supporting habit retained the vascular variant inherited from the ancestor of the subclade. Our study provides insights into how stem vasculature diversified in lianescent clades and how it is related to habit transitions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forecasting ecosystem outcomes of global change can be improved by integrating evolutionary biology and ecosystem science","authors":"Thomas J. Mozdzer,&nbsp;Brian R. Donnelly,&nbsp;Michael J. Blum,&nbsp;Melissa K. McCormick","doi":"10.1002/ajb2.70049","DOIUrl":"10.1002/ajb2.70049","url":null,"abstract":"&lt;p&gt;Aspects of global change including rising seas, warming, increased atmospheric greenhouse gas concentrations, and shifting precipitation regimes can elicit rapid evolution of foundation species (i.e., species that play a vital role in structuring and modifying ecosystems), potentially altering important ecosystem processes including carbon (C) cycling, C storage, nutrient uptake, and nutrient removal. This supposition derives from evidence that heritable traits can influence a range of ecosystem attributes (Whitlock, &lt;span&gt;2014&lt;/span&gt;) and evidence that aspects of global change can act as selective agents on heritable traits (Ravenscroft et al., &lt;span&gt;2015&lt;/span&gt;), giving rise to organismal evolution on an ecological timescale. Yet rapid evolution has largely been neglected in studies of ecosystem responses to global change. Recent work illustrating the importance of addressing this deficit (Vahsen et al., &lt;span&gt;2023&lt;/span&gt;) points to the merits of integrative eco-evolutionary approaches to further understand whether and how evolutionary responses to global change alter ecosystem properties and processes.&lt;/p&gt;&lt;p&gt;Common garden experiments have demonstrated that many species exhibit heritable variation in traits that underlie organismal capacity (e.g., temperature tolerance, salinity tolerance, etc.) to respond to pressures like warming (Mozdzer et al., &lt;span&gt;2016&lt;/span&gt;), elevated carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) (Nakamura et al., &lt;span&gt;2011&lt;/span&gt;), nitrogen enrichment (Kettenring et al., &lt;span&gt;2011&lt;/span&gt;), and interactions thereof (i.e., co-occurring pressures), indicating the potential for selection-driven evolution (i.e., Darwinian evolution). Responses to selection are expected to be contingent on strength of the pressure(s), concurrent biological factors like competition, and genetic factors like trait covariance (Moran and Kubiske, &lt;span&gt;2013&lt;/span&gt;). An increasing number of studies, some involving novel modes of investigation, provide evidence of rapid evolution in response to global change pressures (Kasada and Yoshida, &lt;span&gt;2020&lt;/span&gt;). For example, a century-long record of evolution reconstructed by “resurrecting” soil-stored seeds of the sedge &lt;i&gt;Schoenoplectus americanus&lt;/i&gt; found that shifts in functional traits tightly linked to marsh accretion and C cycling (Rasse et al., &lt;span&gt;2005&lt;/span&gt;) have paralleled changes in precipitation and estuarine salinity in Chesapeake Bay, USA over time (Blum et al., &lt;span&gt;2021&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;An ecosystem attribute or process can be altered by organismal evolution if differences in the expression of a heritable phenotypic trait result in different functional outcomes (Whitham et al., &lt;span&gt;2003&lt;/span&gt;; Whitlock, &lt;span&gt;2014&lt;/span&gt;). In coastal marshes and some riparian ecosystems, heritable traits in smooth cordgrass (&lt;i&gt;Spartina alterniflora&lt;/i&gt;) and cottonwoods (&lt;i&gt;Populus&lt;/i&gt; spp.) can influence the accumulation of soil organic matter (Schweitzer et al., &lt;span&gt;2004&lt;/span&gt;) and microbial commun","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal patterns in the mass flowering of Firmiana simplex: A new case of duodichogamy","authors":"Jing Liu,&nbsp;Zhi-Huan Huang,&nbsp;Jing-Peng Duan,&nbsp;Shuang-Quan Huang","doi":"10.1002/ajb2.70060","DOIUrl":"10.1002/ajb2.70060","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Given that insect-pollinated trees are generally characterized by mass flowering, hermaphrodites may benefit from abundant pollinators but suffer the cost of geitonogamy. To reduce such selfing caused by intraplant pollination, duodichogamy (a temporal sexual system involving three alternating sexual phases within an individual) has been suggested to be a common strategy. However, the timing of the female and male phases within individuals throughout floral phenology remains undocumented in any duodichogamous species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Over 2 years, we quantified flower sexes at the panicle and the plant level throughout flowering in <i>Firmiana simplex</i> to understand how it minimizes geitonogamy. We studied foraging behavior of diverse insects on staminate and pistillate flowers to examine the anther/pollen “advertising” hypothesis, and hand-pollination treatments were used to examine the breeding system.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Flowers on panicles were highly synchronized within the male, then female, then male phases, with only a few days of overlap between pollen release and stigma receptivity. All examined individuals flowered in a sequence of male-female-male. The absence of days when the population contained only female-phase flowers guaranteed that the “expensive” flowers could be pollinated by diverse bees. Five bee species foraged for nectar but not pollen and did not prefer staminate over pistillate flowers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Quantitative measurements of daily flower numbers and sexual phases showed that pistillate flowers were highly synchronous and only a few staminate flowers were out of the female-phase days, minimizing reproductive cost in self-incompatible <i>Firmiana simplex</i>. No evidence for the advertising hypothesis of indehiscent anthers was obtained.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A phylogenetic study of the Cantharellales supports recognition of four families and independent gains of biotrophic nutritional modes","authors":"Rachel A. Swenie,&nbsp;Marc A. Cubeta,&nbsp;Gitta J. Langer,&nbsp;James D. Lawrey,&nbsp;Masoumeh Sikaroodi,&nbsp;Matthew E. Smith,&nbsp;P. Brandon Matheny","doi":"10.1002/ajb2.70054","DOIUrl":"10.1002/ajb2.70054","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The agaricomycete order Cantharellales contains approximately 1000 species of fungi characterized by diverse morphological forms, ecological guilds, and nutritional modes. Examples include coralloid lichens that form symbioses with unicellular green algae, bulbil-forming lichenicolous species, corticioid free-living fungi that degrade dead sources of organic carbon, pathogens that cause plant disease, orchid root endosymbionts, and ectomycorrhizal fungi including popular edible mushrooms. However, evolutionary relationships in the Cantharellales remain poorly understood due to conflicting estimates based on ribosomal DNA loci.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We constructed a five-gene phylogeny of the Cantharellales using data from 301 specimens to evaluate family-level relationships. We used penalized likelihood to estimate divergence times and ancestral state reconstruction to test the hypothesis of multiple independent origins of biotrophic ecologies in the order and whether those transitions are younger than the divergence times of associated plant or lichen hosts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Four monophyletic families were recovered with strong support: Botryobasidiaceae, Ceratobasidiaceae, Hydnaceae s.l., and Tulasnellaceae, with Hydnaceae containing the greatest species richness and morphological diversity. Our results suggest the Cantharellales diverged during the Carboniferous period with subsequent diversification following the Permian-Triassic extinction. Ancestral state reconstruction supports a saprotrophic most recent common ancestor with at least three transitions to an ectomycorrhizal ecology, multiple transitions to a lichenicolous habit with one or more subsequent transitions to mutualistic nutritional modes, four transitions to an orchid mycorrhizal ecology, and two transitions to a lichenized lifestyle.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study represents the first comprehensive examination of the evolution of form and function across this ecologically and morphologically diverse order of fungi.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144224040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}