American Journal of Botany最新文献

{"title":"Global patterns in community-scale leaf mass per area distributions of extant woody non-monocot angiosperms and their utility in the fossil record","authors":"Alexander J. Lowe,&nbsp;Dana L. Royer,&nbsp;Daniel J. Wieczynski,&nbsp;Matthew J. Butrim,&nbsp;Tammo Reichgelt,&nbsp;Lauren Azevedo-Schmidt,&nbsp;Daniel J. Peppe,&nbsp;Brian J. Enquist,&nbsp;Andrew J. Kerkoff,&nbsp;Sean T. Michaletz,&nbsp;Caroline A. E. Strömberg","doi":"10.1002/ajb2.70019","DOIUrl":"10.1002/ajb2.70019","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Leaf mass per area (LMA) links leaf economic strategies, community assembly, and climate and can be reconstructed from woody non-monocot angiosperm (WNMA) fossils using the petiole metric (PM; petiole width²/leaf area). Reliable interpretation of LMA reconstructed from the fossil record is limited by an incomplete understanding of how PM and LMA are correlated at the community scale and what climatic parameters drive variation of both measured and reconstructed LMA of WNMAs globally.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A modern, global, community-scale data set of in situ WNMA LMA and PM was compiled to test leading hypotheses for environmental drivers of LMA and quantify LMA-PM relationships. Correlations among PM, LMA, climate (Köppen types and continuous data), and leaf habit were assessed and quantified using several uni- and multivariate methods.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Community mean LMA increased under warmer and less seasonal temperatures. Drought-prone communities had the highest LMA variance, likely due to disparity between riparian and non-riparian microhabitats. PM and LMA were correlated for community mean and variance, and their correlations with climate were similar. These patterns indicate that climatic correlatives of modern LMA can inform relative trends in reconstructed fossil LMA. In contrast, matching “absolute” LMA distributions between fossil and modern sites does not allow reliable inference of analogous climate types.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study furthers our understanding of processes influencing the assembly of WNMA leaf economic strategies in plant communities, highlighting the importance of temperature seasonality and habitat heterogeneity. We also provide a method to reconstruct, and refine the framework to interpret, community-scale LMA in the fossil record.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 4","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143690539","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":"Soil biome variation of Lupinus nipomensis in wet-cool vs. dry-warm microhabitats and greenhouse","authors":"Peter T. Nguyen,&nbsp;Justin C. Luong,&nbsp;Van Wishingrad,&nbsp;Lisa Stratton,&nbsp;Michael E. Loik,&nbsp;Rachel S. Meyer","doi":"10.1002/ajb2.70020","DOIUrl":"10.1002/ajb2.70020","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Environmental DNA (eDNA) can be used to determine the composition of the soil biome community, revealing beneficial and antagonistic microbes and invertebrates associated with plants. eDNA analyses can complement traditional soil community studies, offering more comprehensive information for conservation practitioners. Studies are also needed to examine differences between field and greenhouse soil biomes because greenhouse-grown plants are often transplanted in the field during restoration efforts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used eDNA multilocus metabarcoding to test how the soil biome of the federally and state-endangered species, <i>Lupinus nipomensis</i>, differed between wet-cool and dry-warm microhabitats. At Arroyo Grande, California, 20 experimental plots were sampled, representing a factorial combination of wet-cool vs. dry-warm soil and plots that did or did not contain <i>L. nipomensis</i>. In a simultaneous greenhouse study, <i>L. nipomensis</i> was grown in drought and well-watered conditions to compare soil communities between field and greenhouse.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A diversity of carbon-cycling microorganisms but not nitrogen-fixers were overrepresented in the field, and nitrogen-fixing bacteria were overrepresented in some greenhouse treatments. The microbial communities in the field soils were more species-rich and evenly distributed than in greenhouse communities. In field plots, microhabitats significantly influenced community beta diversity, while field plots with or without <i>L. nipomensis</i> had no significant differences in alpha or beta diversity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our study shows the utility of eDNA soil analysis in elucidating soil biome community differences for conservation and highlights the influence of plant microhabitats on soil microbe associations.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 4","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143668894","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":"Extreme fire severity interacts with seed traits to moderate post-fire species assemblages.","authors":"Michi Sano, Ryan Tangney, Alexandria Thomsen, Mark K J Ooi","doi":"10.1002/ajb2.70012","DOIUrl":"https://doi.org/10.1002/ajb2.70012","url":null,"abstract":"<p><strong>Premise: </strong>Climate change is globally pushing fire regimes to new extremes, with unprecedented large-scale severe fires. Persistent soil seed banks are a key mechanism for plant species recovery after fires, but extreme fire severity may generate soil temperatures beyond thresholds seeds are adapted to. Seeds are protected from lethal temperatures through soil burial, with temperatures decreasing with increasing depth. However, smaller seeds, due to their lower mass and corresponding energy stores, are restricted to emerging from shallower depths compared to the depths for larger seeds. We examined recruitment patterns across a landscape-scale gradient of fire severity to determine whether seed mass and dormancy class mediate shifts in community assemblages.</p><p><strong>Methods: </strong>We surveyed 25 sites in wet sclerophyll forests in southeastern Australia that had been burnt at either moderate, high, or extreme severity during the 2019-2020 Black Summer Fires. We measured abundance and calculated density of seedlings from 27 common native shrub species.</p><p><strong>Results: </strong>Extreme severity fires caused significant declines in seedling recruitment. Recruitment patterns differed between dormancy class, with steeper declines in seedling emergence for species with physiologically dormant (PD) than for physically dormant (PY) seeds at extreme fire severity. Relative emergence proportions differed between fire severity and seed size groups for both PY and PD species.</p><p><strong>Conclusions: </strong>Large-scale extreme severity fires favor larger-seeded species, shifting community composition. Future recurrent extreme fire events could therefore place smaller-seeded species at risk. Seed mass, dormancy class, and other seed traits should be considered when exploring post-fire responses, to better predict impacts on plant species.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70012"},"PeriodicalIF":2.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646777","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 phylogenomic investigation into the biogeography of the Mexico–eastern U.S. disjunction in Symphyotrichum","authors":"Sushil Dahal,&nbsp;Carolina M. Siniscalchi,&nbsp;Ryan A. Folk","doi":"10.1002/ajb2.70021","DOIUrl":"10.1002/ajb2.70021","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Biotic disjunctions have attracted scientific attention for the past 200 years. Despite being represented in many familiar plants (such as bald cypress, flowering dogwood, sweetgum, partridgeberry, etc.), the eastern North American (ENA)–Mexican (M) disjunction remains poorly understood. Major outstanding questions include the divergence times of taxa exhibiting the disjunction and environmental/geological processes that may underlie the disjunction. <i>Symphyotrichum</i> Nees (Asteraceae), one of the most diverse genera in the eastern USA, displays several examples of disjunct ENA–M taxa.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We generated target capture data using the Angiosperms353 baitset and generated the first well-sampled phylogenomic hypothesis for <i>Symphyotrichum</i> and its close relatives. Focusing on <i>S</i>. subgenus <i>Virgulus</i>, we used MCMC_TREE to perform divergence time estimation and the R package BioGeoBEARS to infer ancestral regions and biogeographic transitions between North America and Mexico. Finally, we used the ancestral niche reconstruction method Utremi to test for a role of historical aridification in generating the disjunction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our molecular data suggest a recent radiation of <i>Symphyotrichum</i> at the Plio-Pleistocene boundary (~2.5 mya), with early connections to Mexico in ancestral lineages that closed off shortly after and were followed by vicariance across this region. Except for some present-day broadly distributed species, there is a complete lack of movement between ENA and M after ~0.5 mya.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>A reconstructed disjunct distribution of suitable habitat in Pleistocene climatic models corroborates results from biogeographic modeling and confirms glacial cycles are more likely to be associated with the breakup of ENA–M biogeographic connections.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646776","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":"Gelatinous fibers develop asymmetrically to support bends and coils in common bean vines (Phaseolus vulgaris)","authors":"Joyce G. Onyenedum,&nbsp;Mariane S. Sousa-Baena,&nbsp;Lena M. Hunt,&nbsp;Angelique A. Acevedo,&nbsp;Rosemary A. E. Glos,&nbsp;Charles T. Anderson","doi":"10.1002/ajb2.70014","DOIUrl":"10.1002/ajb2.70014","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Gelatinous (G)-fibers are specialized fibers that generate tensile force to bend and straighten many plant organs; this phenomenon has been intensively studied in tension wood of trees. Previous work has shown that G-fibers are common within the stems of twining vines, but we lack the spatiotemporal developmental data required to determine whether, or how, G-fibers contribute to the movement and/or stabilization of twining tissues.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We employed multiple histochemical approaches to characterize the formation and cell wall architecture of G-fibers in twining and shrub phenotypes of common bean across a developmental time series.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Within an internode, G-fibers first formed asymmetrically via differentiation of pericyclic fibers on the concave side of an existing bend and later arose erratically from the vascular cambium. G-fibers were absent in immature and/or actively circumnutating internodes, thus validating previous reports that G-fibers are not involved in rapid dynamic movements. Instead, G-fibers formed in stationary internodes, where they developed (1) in an alternating asymmetric pattern, likely to support the posture maintenance of erect internodes at the base of twiners and throughout the length of shrubs or (2) on the concave side of twined internodes to stabilize their helical conformation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our spatiotemporal results indicate that common bean vines form G-fibers after an internode has fully elongated and becomes stationary, thus functioning to stabilize the posture of subtle bends and coil internodes. These results contribute to understanding how twining vines establish and maintain a grip on their host or supporting structure.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143633354","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":"Soil and climate contribute to maintenance of a flower color polymorphism.","authors":"Dena L Grossenbacher, Magdalene S Lo, Molly E Waddington, Ryan O'Dell, Kathleen M Kay","doi":"10.1002/ajb2.70018","DOIUrl":"https://doi.org/10.1002/ajb2.70018","url":null,"abstract":"<p><strong>Premise: </strong>Floral pigments such as anthocyanins are well known to influence pollinator attraction, yet they also confer tolerance to abiotic stressors such as harsh soils, extreme temperatures, low precipitation, and UV radiation. In such cases, environmental variation in abiotic stressors over space or time could lead to the maintenance of flower color variation within species. Under this scenario, flower color in natural populations should covary with environmental stressors.</p><p><strong>Methods: </strong>Using a comparative approach, we tested whether abiotic variables predict flower color in Leptosiphon parviflorus, a species with pink and white flower color morphs. We conducted in-depth field studies to assess morph frequency, soil chemistry, and climate. We then employed community scientist-powered iNaturalist observations to examine patterns across even larger spatial scales.</p><p><strong>Results: </strong>Across 21 field sites, L. parviflorus had a higher frequency of pink morphs in sites with serpentine soil, higher average annual temperatures, and higher average climatic water deficit (a proxy for drought stress). iNaturalist observations supported this finding-the probability of flowers being pink is greater in locations with serpentine-derived soil, especially when the local average UV radiation and climatic water deficit are higher.</p><p><strong>Conclusions: </strong>Spatial variation in abiotic stressors may contribute to the maintenance of flower color variation across the geographic range of L. parviflorus. Future studies will examine mechanisms by which flower color affects stress tolerance and will assess whether fitness trade-offs in contrasting habitats across the range are associated with flower color.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70018"},"PeriodicalIF":2.4,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623107","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":"Grass functional traits reflect the long history of fire and grazers in the savannas of Texas.","authors":"Ashish N Nerlekar, Daniel Spalink, Joseph W Veldman","doi":"10.1002/ajb2.70013","DOIUrl":"https://doi.org/10.1002/ajb2.70013","url":null,"abstract":"<p><strong>Premise: </strong>Understanding relationships among grass traits, fire, and herbivores may help improve conservation strategies for savannas that are threatened by novel disturbance regimes. Emerging theory, developed in Africa, emphasizes that functional traits of savanna grasses reflect the distinct ways that fire and grazers consume biomass. Specifically, functional trade-offs related to flammability and palatability predict that highly flammable grass species will be unpalatable, while highly palatable species will impede fire.</p><p><strong>Methods: </strong>We quantified six culm and leaf traits of 337 native grasses of Texas-a historical savanna region that has been transformed by fire exclusion, megafaunal extinctions, and domestic livestock.</p><p><strong>Results: </strong>Multivariate analyses of traits revealed three functional strategies. \"Grazer grasses\" (N = 50) had culms that were short, narrow, and horizontal, and leaves with high width to length (W:L) and low C to N ratios (C:N)-trait values that attract grazers and avoid fire. \"Fire grasses\" (N = 104) had culms that were tall, thick, and upright, and leaves that were thick, with low W:L, and high C:N-trait values that promote fire and discourage grazers. \"Generalist tolerators\" and \"generalist avoiders\" (N = 183) had trait values that were intermediate to the other groups.</p><p><strong>Conclusions: </strong>Our findings confirm that the flammability-palatability trade-offs that operate in Africa also explain correlated suites of traits in Texas grasses and highlights that the grass flora of Texas bears the signature of Pleistocene megafauna and the influence of fires that predate human arrival. We suggest that grass functional classifications based on fire and grazer traits can improve prescribed fire and livestock management of savannas of Texas and globally.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70013"},"PeriodicalIF":2.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595972","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":"Endophytic bacteria discovered in oil body organelles of the liverworts Marchantia polymorpha and Radula complanata","authors":"Blair C. Young,&nbsp;Barbara Thiers,&nbsp;James F. White,&nbsp;Lena Struwe","doi":"10.1002/ajb2.70017","DOIUrl":"10.1002/ajb2.70017","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Interactions between endophytic microbes and bryophytes have been understudied. The liverwort oil body has also remained poorly understood since its discovery, and modern studies have failed to ascertain its function and composition. Many liverwort species possess oil bodies with conspicuous granules of unknown structure. We surveyed these granular liverwort oil bodies for the presence of bacteria to improve upon the understanding of liverworts, their oil bodies, and bacterial endophytes in nonvascular land plants.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Wild-collected specimens from living samples of <i>Marchantia polymorpha</i> and <i>Radula complanata</i> were stained with SYTO-13 and RADA to determine the presence or absence of bacteria within their oil bodies. Samples stained with calcofluor white, SYTO-13, and RADA were observed with confocal fluorescent microscopy for presence of nucleic acids and bacterial peptidoglycan cell walls within oil bodies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We discovered large masses of bacteria within the oil bodies of <i>M. polymorpha</i> and <i>R. complanata</i> based on the presence of stained nucleic acids and peptidoglycans localized to the oil body “granules”. Such bacteria were present in all oil bodies of the two species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These newly discovered intraorganellar bacteria correspond to the previously described “granules” of oil bodies. The existence of granular oil bodies in many liverwort species implies that this endophytic association may not be isolated to species investigated here. Assessments of additional liverwort species for presence and identity of oil body bacteria are needed to understand this intriguing association in one of the oldest land plant lineages.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143603553","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":"Phylogenetic relationships and the repeated loss of traits associated with sicklebill pollination in Centropogon subgenus Centropogon (Campanulaceae)","authors":"Janet K. Mansaray,&nbsp;Ana M. Bedoya,&nbsp;Laura A. Frost,&nbsp;Olivia C. Degreenia,&nbsp;Laura P. Lagomarsino","doi":"10.1002/ajb2.70016","DOIUrl":"10.1002/ajb2.70016","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p><i>Centropogon</i> subgenus <i>Centropogon</i> comprises 55 species found primarily in midelevation Andean forests featuring some of the most curved flowers among angiosperms. Floral curvature is linked to coevolution with the sicklebill hummingbird, which pollinates most species. Despite charismatic flowers, there is limited knowledge about the phylogenetic relationships and floral evolution.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We conducted the first densely sampled phylogenomic analysis of the clade using methods that account for incomplete lineage sorting on a sequence capture dataset generated with a lineage-specific probe set. Using phylogenetic comparative methods, we test for correlated evolution of two traits central to sicklebill pollination.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We improve understanding of species relationships by more than doubling past taxon sampling. We confirm the monophyly of the subgenus and two sections, and the non-monophyly of remaining sections. The subgenus is characterized by high gene tree discordance. Three widespread species display contrasting phylogenetic dynamics, with <i>C. cornutus</i> forming a clade and <i>C. granulosus</i> and <i>C. solanifolius</i> forming non-monophyletic, biogeographically clustered lineages. Correlated evolution of floral curvature and inflorescence structure has led to multiple putative losses of sicklebill pollination.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p><i>Centropogon</i> subgenus <i>Centropogon</i> adds to a growing body of literature of Andean plant clades with high gene tree discordance. This phylogeny serves as a foundational framework for further macroevolutionary investigations into the environmental and biogeographic factors shaping the evolution of pollination-related traits.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596004","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":"Latitudinal clines in the phenology of floral display associated with adaptive evolution during a biological invasion","authors":"Mia N. Akbar,&nbsp;Dale R. Moskoff,&nbsp;Spencer C. H. Barrett,&nbsp;Robert I. Colautti","doi":"10.1002/ajb2.70015","DOIUrl":"10.1002/ajb2.70015","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Flowering phenology strongly influences reproductive success in plants. Days to first flower is easy to quantify and widely used to characterize phenology, but reproductive fitness depends on the full schedule of flower production over time. We investigated flowering schedules in relation to the onset and duration of flowering and tested for latitudinal clines in schedule shape associated with rapid evolution and range expansion of an invasive plant.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined floral display traits among 13 populations of <i>Lythrum salicaria</i>, sampled along a 10-degree latitudinal gradient in eastern North America. We grew these collections in a common garden field experiment at a mid-latitude site and quantified variation in flowering schedule shape using principal coordinate analysis (PCoA) and quantitative metrics analogous to central moments of probability distributions (i.e., mean, variance, skew, and kurtosis).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Consistent with earlier evidence for adaptation to shorter growing seasons, we found that populations from higher latitudes had earlier start and mean flowering day, on average, when compared to populations from southern latitudes. Flowering skew increased with latitude, whereas kurtosis decreased, consistent with a bet-hedging strategy in biotic environments with more herbivores and greater competition for pollinators.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Heritable clines in flowering schedules are consistent with adaptive evolution in response to a predicted shift toward weaker biotic interactions and less variable but more stressful abiotic environments at higher latitudes, potentially contributing to rapid evolution and range expansion of this invasive species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584367","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}