American Journal of Botany最新文献

{"title":"Spatial genetic structure of Arundinaria appalachiana (hill cane), an upland bamboo species endemic to the southern Appalachian Mountains, USA","authors":"Jonathan P. Evans,&nbsp;Ashley B. Morris","doi":"10.1002/ajb2.70159","DOIUrl":"10.1002/ajb2.70159","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Long-lived clonal plants that rarely or never reproduce sexually raise important questions about persistence, genetic diversity, and extinction risk. <i>Arundinaria appalachiana</i>, an upland bamboo endemic to the southern Appalachian Mountains, has never been observed to flower. We investigated the spatial genetic structure and demography of this species to assess how it persists and to inform its conservation status.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used genotype-by-sequencing of microsatellite loci to characterize clonal structure in two populations separated by 19 km on the southern Cumberland Plateau in Tennessee, USA. Rhizome networks were mapped over 8 yr to estimate rates of clonal expansion and infer genet age. Ramet density was monitored annually to detect demographic changes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Both populations were dominated by a few large, ancient genets; the largest covered &gt;30 ha and was estimated to be &gt;1700 yr old. Clonal diversity was low, and no flowering was observed during the 9 yr study. Rhizome mapping showed slow expansion (0.12–0.30 m yr⁻¹) and local fragmentation. Ramet density declined significantly in one population, while remaining stable in the other.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p><i>Arundinaria appalachiana</i> persists through clonal growth alone, forming extensive, ancient genets in the absence of sexual reproduction. This clonal longevity enables persistence, but the lack of genetic renewal raises concerns about long-term viability in changing environments. Our findings highlight the importance of understanding spatial genetic structure in clonal plant populations and its consequences for conservation planning.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146099919","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":"Phylogenomics reveals the evolution of floral traits associated with pollinators and pollinator–prey conflict within the carnivorous Pinguicula subgenus Temnoceras","authors":"Yunjia Liu,&nbsp;Qianshi Lin,&nbsp;Steven J. Fleck,&nbsp;Martín Mata-Rosas,&nbsp;Enrique Ibarra-Laclette,&nbsp;Tanya Renner","doi":"10.1002/ajb2.70156","DOIUrl":"10.1002/ajb2.70156","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The carnivorous plant genus <i>Pinguicula</i> (Lentibulariaceae) exhibits remarkable floral diversity associated with pollination, particularly in the largest subgenus <i>Temnoceras</i>, which spans Mexico and Central America. Despite this diversity, the relationships between species and the evolution of key floral traits remain unresolved. Here, we employed whole-genome sequencing to reconstruct a robust phylogeny and examine the evolution of pollination syndromes and potential pollinator–prey conflicts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We generated nuclear and plastid genomic data for 32 <i>Pinguicula</i> species. Phylogenetic relationships were inferred using 2189 BUSCO loci analyzed through ASTRAL. Morphological traits associated with pollination and carnivory were assessed with ancestral state reconstruction, principal component analysis, and phylogenetic linear models. Loss and pseudogenization of <i>ndh</i> genes implicated in potential shifts in trophic strategies were evaluated in both nuclear and plastid genomes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our genome-scale phylogeny resolved six monophyletic clades within <i>Temnoceras</i>, refining infrageneric classification. Most <i>ndh</i> genes are either lost or pseudogenized across both genomic compartments. Floral morphology strongly clusters by pollinator type, with fly-pollinated species forming a distinct clade characterized by cylindrical spurs and tubes. Ancestral reconstructions indicate multiple independent transitions in spur and tube morphology. Phylogenetic linear modeling revealed a significant evolutionary correlation between scape length and carnivorous leaf area, suggesting that spatial separation may represent an adaptive response to mitigate pollinator–prey conflict.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study provides a refined phylogenetic framework for <i>Pinguicula</i> subgenus <i>Temnoceras</i> and highlights how pollinator specialization and carnivory-related traits contribute to floral evolution.The repeated loss of <i>ndh</i> genes implies relaxed selective pressure on photosynthesis-related pathways in these carnivorous species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146091646","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":"Phylogenomics, ecomorphological evolution, and historical biogeography in Deuterocohnia (Bromeliaceae: Pitcairnioideae)","authors":"Bing Li,&nbsp;Nicole Schütz,&nbsp;Kurt Weising,&nbsp;Georg Zizka,&nbsp;Jacob B. Landis,&nbsp;Thomas J. Givnish","doi":"10.1002/ajb2.70153","DOIUrl":"10.1002/ajb2.70153","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Species of <i>Deuterocohnia</i> (17 spp.) show extraordinary variation in elevation (0–3900 m a.s.l.) and growth forms, and many have narrow geographic distributions in the west-central Andes and the Peru-Chile coast. Previous research using few plastid and nuclear loci failed to produce well-resolved or supported phylogenies. Here we sequenced 1815 single-copy nuclear genes and whole plastomes to infer relationships, screen for reticulation, reconstruct evolution of vegetative and floral characters, and evaluate species groups and their historical biogeography.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We developed the Bromeliad1815 bait set to capture low-copy nuclear genes across Bromeliaceae, producing nuclear and plastome phylogenies for <i>Deuterocohnia</i> and outgroups in six bromeliad subfamilies using maximum likelihood, ASTRAL, and network analyses; test for cytonuclear conflict and its potential causes; and evaluate evolution of morphological characters in relation to each other and elevation using phylogenetic PCA and phylogenetic regression.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We produced fully resolved, strongly supported nuclear and plastome phylogenies for <i>Deuterocohnia</i>, with crown ages of 5.5 and 8.0 Mya, respectively. Cytonuclear conflict appears driven mainly by hybridization/introgression, consistent with several species co-occurring in small areas. Vegetative organs and growth form become increasingly compact with elevation, reflecting adaptation to desiccation, wind exposure, and cold soils. <i>Deuterocohnia</i> arose in southeastern Bolivia and repeatedly evolved up- and downslope into other habitats from Andean Yungas at mid-elevation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results imply rapid adaptive divergence (e.g., in <i>strobilifera-chrysantha</i>), convergent evolution (two origins of the cushion growth-form), phylogeny consistent with form in some cases (e.g., <i>seramisiana-brevispicata-meziana</i>) and recurrent effects of the Rio Pilcomayo barrier on speciation and chloroplast capture.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70153","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146058520","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":"Testing the importance of ectomycorrhizas and nutrients for the growth of dipterocarp seedlings in Borneo","authors":"Francis Q. Brearley","doi":"10.1002/ajb2.70155","DOIUrl":"10.1002/ajb2.70155","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>A number of ecologically important tropical trees form symbiotic ectomycorrhizal (EcM) fungal associations including the Dipterocarpaceae, that dominate lowland forests of South-east Asia. Whilst numerous pot-based studies have focused on the importance of EcMs for dipterocarp seedling growth and performance, few field studies have been undertaken.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In a 20-month field experiment in Malaysian Borneo, two species with contrasting light requirements—shade-tolerant <i>Hopea nervosa</i> and the more light-demanding <i>Parashorea tomentella</i>—were subjected to the factorial addition of fungicide (to reduce EcM colonization) and nutrients.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Fungicide addition reduced EcM colonization by a small but significant percentage. Reductions in foliar nitrogen, phosphorus, and chlorophyll concentrations in both species and in calcium and magnesium concentrations in <i>H. nervosa</i> did not translate into reduced biomass in either species. When given additional nutrients, <i>H. nervosa</i> had no increase in foliar nutrient concentrations or biomass, but <i>P. tomentella</i> had an increase in foliar nitrogen, phosphorus, and magnesium concentrations and more than doubled its biomass. When nutrients were added but EcM reduced, <i>P. tomentella</i> did not increase in biomass.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>EcM fungi can play an important role in influencing dipterocarp seedling mineral nutrition, and <i>P. tomentella</i> may require EcMs to effectively utilize additional mineral nutrient sources. The importance of nutrient uptake for biomass production is less clear and may be confounded by the use of fungicide to control EcM colonization.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146058464","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":"Wind-driven seed dispersal differentially promotes seed trapping and retention across alpine plants","authors":"Courtenay A. Ray,&nbsp;Savannah R. Troy,&nbsp;Emily V. Xie,&nbsp;Thomas M. Jenkins,&nbsp;Gavin Belfry,&nbsp;Aidan Wells,&nbsp;Perry de Valpine,&nbsp;Benjamin W. Blonder","doi":"10.1002/ajb2.70151","DOIUrl":"10.1002/ajb2.70151","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Seed dispersal can mediate species interactions between plants across life stages. Plants can physically stop seed movement (seed trapping) and prevent further dispersal following entrapment (seed retention). We therefore hypothesized seed trapping and retention rates depend on the physical attributes of interacting seeds and plants, including seed traits and plant length.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>For combinations of co-occurring plant species in an alpine community, we experimentally measured seed trapping and retention potential. To measure seed trapping, we determined the rate at which seeds were unable to physically pass through vegetation without stopping after being launched at plants. To assess seed retention, we compared the rate that seeds left vegetation following entrapment across plant and seed species and by seed traits.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Seed trapping rates were higher for larger-sized plants and differed among plant species but not seed species. Seed trapping and retention rates were higher for plant species with denser vegetation. Seeds with a pappus were retained less than seeds without, and we observed interactive effects between plant and seed species identity on retention rates.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Seed trapping and retention rates are influenced by species identities and the physical attributes of plants and seeds. Because both processes can contribute to where a seed is ultimately dispersed, seed trapping and retention may mediate species co-occurrence and further species interactions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70151","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146040337","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":"Dimorphic enantiostyly and its function for pollination by carpenter bees in a pollen-rewarding Caribbean bloodwort","authors":"Steven D. Johnson,&nbsp;Jeremy J. Midgley,&nbsp;Luis G. Bocourt-Hernandez,&nbsp;F. G. Loiret,&nbsp;Patricia Ortega-Rodés,&nbsp;Nicola Illing","doi":"10.1002/ajb2.70148","DOIUrl":"10.1002/ajb2.70148","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Flowers that present their anthers and stigma in close proximity can achieve precise animal-mediated pollen transfer, but risk self-pollination. One evolutionary solution is reciprocal herkogamy. Reciprocity of anther and style positions among different plants (i.e., a genetic dimorphism) is common in distylous plants, but very rare in enantiostylous plants. We investigated the pollination and reproductive system of the enantiostylous Caribbean plant <i>Cubanicula xanthorrhizos</i> (Haemodoraceae).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We assessed stylar orientation of flowers and conducted controlled pollination experiments. We used videography of flower visitors and pollen load analysis to determine the pollination mechanism. We also measured floral morphology, pollen production, spectral reflectance, and volatile emissions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p><i>Cubanicula xanthorrhizos</i> exhibits dimorphic enantiostyly with c. 50:50 left- to right-styled morphs. Plants are self-compatible, but pollinator dependent for seed production. Intra- and intermorph crosses are equally fertile. The nectarless flowers are pollinated by female carpenter bees (<i>Xylocopa cubaecola</i>) that collect pollen, often by sonication, from two centrally positioned yellow feeding anthers. An inconspicuous deflected pollinating anther deposits pollen on the side of the bee thorax, which contacts the stigma of the mirror-image morph. A yellow-orange “guide” on the white tepals appears to be a visual attractant. Flowers emit methoxy benzenoid volatiles that may also attract bees.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Reciprocity of the style with a single pollinating stamen in <i>C. xanthorrhizos</i> appears to promote intermorph pollen export via “safe sites” on pollen-collecting bees. This novel case of dimorphic enantiostyly contributes to understanding of the evolution of floral polymorphisms.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12918842/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146017012","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":"Paradigm shifts in flower color: An introduction","authors":"Andrea E. Berardi,&nbsp;José Carlos del Valle,&nbsp;Matthew H. Koski,&nbsp;Eduardo Narbona,&nbsp;Justen Whittall","doi":"10.1002/ajb2.70150","DOIUrl":"10.1002/ajb2.70150","url":null,"abstract":"&lt;p&gt;Flower color plays a central role in pollination, functioning as one of the major traits attracting pollinators. The close relationship between flower color phenotypes and pollination has been studied extensively, and we are still learning about the intricacies of the role of flower color in plant–pollinator relationships. However, there are also other alternative, complementary, and important functions that flower color plays a role in, often due to alternative functions of pigments behind the color, the traits that are tightly correlated with flower color, or structural epidermal changes. For example, many of the flavonoid-based pigments (including anthocyanins) in plants function as antioxidants or provide protection against extreme temperatures, drought, UV radiation, pathogens, herbivores, and other selective agents. These additional pigment functions may explain the current distribution of flower colors across environmental gradients and may have important consequences when interpreting plant adaptations to pollinators and their environment, particularly in the face of rapid and ongoing changes in climate globally (Koski et al., &lt;span&gt;2020&lt;/span&gt;; Sullivan et al., &lt;span&gt;2021&lt;/span&gt;; Lacey, &lt;span&gt;2025&lt;/span&gt;). Carotenoids and betalains, the other major groups of flower pigments, also have antioxidant activity, although their protective roles in flowers are less well characterized.&lt;/p&gt;&lt;p&gt;The purpose of this special issue is not to question or diminish the role of pollinators in flower color diversity, but rather to highlight the alternative, complementary, and even antagonistic roles, selective pressures, and macroevolutionary patterns that can shape flower color—reflecting an emerging paradigm shift in how we study and understand floral color. The articles in this special issue cover a broad range of approaches to study and assess flower color in the field, greenhouse, and laboratory including biochemical quantification, reflectance spectra, photography, physics, modeling, citizen-science databases, and herbarium collections.&lt;/p&gt;&lt;p&gt;The research in this special issue helps to expand our understanding of the forces shaping flower color, revealing complex interplays between biotic partners, abiotic conditions, and intrinsic physiological and macroevolutionary correlations and constraints. For example, Sinnott-Armstrong et al. (&lt;span&gt;2026&lt;/span&gt;) link macroevolutionary patterns of flower and fruit color across lineages, and Dellinger et al. (&lt;span&gt;2025&lt;/span&gt;) challenge a long-standing paradigm that flower colors are primarily molded by animal visual systems, instead highlighting that flowers and fruits often experience distinct suites of abiotic selective pressures. This shift toward a more integrative framework is echoed by studies demonstrating environmentally and ecologically mediated divergence. Camargo et al. (&lt;span&gt;2026&lt;/span&gt;) show how both biotic and abiotic factors drive the diversification of color traits across the mosaic landscap","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146002833","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":"Flower clades and fruit clades: Trade-offs in color diversification across angiosperms","authors":"Miranda Sinnott-Armstrong,&nbsp;Leah Maier,&nbsp;Stacey D. Smith,&nbsp;Agnes S. Dellinger","doi":"10.1002/ajb2.70146","DOIUrl":"10.1002/ajb2.70146","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Flowers and fruits are two major phases of plant reproduction that often use colorful signals to attract animal mutualists. Fruits develop from the ovaries of flowers, and both organs use the same suites of pigments to create color. These developmental links and functional similarities led us to test for correlations in flower and fruit color lability across clades.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We selected 51 clades (2960 species) of animal-pollinated and animal-dispersed (i.e., fleshy-fruited) plants and scored flower and fruit color into eight discrete (human-perceived) categories for the same set of species in each clade. We used stochastic character mapping to estimate the number and rates of transitions among colors in flowers and fruits.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The number of transitions in flower and fruit color was negatively correlated across clades (<i>R</i>² = 0.41; <i>P</i> &lt; 0.001). Among animal-pollinated and animal-dispersed clades, 67% were “fruit clades” biased toward fruit color lability, while 29% were “flower clades” biased toward flower color lability. Furthermore, clades with yellow- or orange-flowered species also tended to have those colors in their fruits, and red flowers were more common in “flower clades” and brown fruits in “fruit clades”.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These patterns suggest that clades specialize on one phase of reproduction or the other. Possible explanations include constraints on energetic investment into either pollination or dispersal, environmental factors that select for color diversification in one organ but not the other, or constraints imposed by the underlying structure of pigment pathways.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145997075","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":"Thanks to our valued reviewers—2025","authors":"","doi":"10.1002/ajb2.70152","DOIUrl":"10.1002/ajb2.70152","url":null,"abstract":"","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70152","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145987801","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":"Flowers occupy color-space extremes: an anthocyanin-derived theoretical floral color-space approach","authors":"Jacob L. Watts,&nbsp;Nicolás Medina,&nbsp;Carrie Kiel,&nbsp;Manuel Luján,&nbsp;Stacey D. Smith,&nbsp;Erin A. Manzitto-Tripp","doi":"10.1002/ajb2.70149","DOIUrl":"10.1002/ajb2.70149","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Floral color is a stunning, complex trait that has long served as a model for connecting genetics, development, evolution, and ecology. Nevertheless, few mechanistic models relate flower color to the pigments that produce variation, nor has there been much exploration into theoretically possible flower color variation. Here we explored these topics using an anthocyanin-derived theoretical color-space approach.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We characterized flower color, floral anthocyanin concentrations, evolutionary history, and biogeography for 51 species of neotropical <i>Ruellia</i> to compare extant color diversity to an anthocyanin-derived theoretical color space and analyzed potential drivers of variation. To build the color space, we utilized reflectance spectrometry, HPLC, double-digest restriction-site-associated next-generation sequencing, and an extensive data set of <i>Ruellia</i> occurrences.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>An anthocyanin floral color model predicted a significant portion of the observed variation in reflectance spectra. Flowers spanned most of the theoretically possible color space, but with phenotypes clustered at the extreme edges of the space. Species of <i>Ruellia</i> exhibited less biochemical constraint than other well-studied lineages, commonly producing three or more types of anthocyanins (39%), but still showed evidence of constraint. Shared evolutionary history and biogeographical overlap were not strong predictors of color disparity between species pairs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Anthocyanins were primary predictors of flower color in <i>Ruellia</i>, but a significant portion of variation remained unexplained by our model, implicating additional mechanisms (e.g., co-pigmentation and pH) underlying flower color. Modeling color space provided a powerful framework for quantifying evolutionary constraints, offering insights into the mechanisms shaping phenotypic diversity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145987760","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}