American Journal of Botany最新文献

{"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}

{"title":"The role of leaf and root functional traits in the Espeletiinae (Asteraceae) radiation","authors":"Valeria Vargas-Martínez,&nbsp;Adriana Sanchez","doi":"10.1002/ajb2.70011","DOIUrl":"10.1002/ajb2.70011","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Key innovations within a group result in ecological divergence. Those innovations involve functional traits that may reflect the species' adaptations to environmental conditions and to interactions within the community. The subtribe Espeletiinae is considered an adaptive radiation due to their exceptional diversity. In this study, we explored the role that functional traits have in this radiation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Nine functional traits (leaf and root) were measured in co-occurring species of five páramo complexes in Colombia. We used a principal component analysis to understand the climatic differences between complexes and to define the functional space of the species. Welch's ANOVA and <i>t</i>-test were used to unveil significant differences among co-occurring species. We also used normal mixture models (NMMs) to reassemble species based on the functional trait data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Páramo complexes were partially separated in climatic conditions of temperature and precipitation. Leaf traits exhibited more significant differences among co-occurring species within each complex compared to root traits. <i>Espeletia glandulosa</i> was the only species that showed a species-specific combination of traits and formed a cluster in the NMM analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>There is a more pronounced variation in leaf traits among co-occurring species, suggesting a potential ecological diversity driver. We propose that there is convergence and stabilization of traits, given the colonization of similar habitats by species belonging to Espeletiinae. We highlight the need for studying the role of other functional traits in the ecological differentiation of species within this group to elucidate how they coexist and cope with environmental conditions of the páramo.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143565761","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":"Evaluating the combined effects of light and water availability on the early growth and physiology of Tamarindus indica: Implications for restoration","authors":"Ariadna Mondragón-Botero,&nbsp;Jennifer S. Powers","doi":"10.1002/ajb2.70008","DOIUrl":"10.1002/ajb2.70008","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The tamarind tree (<i>Tamarindus indica</i>) is a species of significant cultural, economic, and ecological value, with a pantropical distribution. However, the tamarind is experiencing a decline in wild populations in its native range, but the reasons for its decline remain unknown.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined the critical early life-history stages for tamarind establishment to understand how varying levels of light and water availability and watering frequency affect its regeneration. Through three greenhouse experiments, we assessed the impact of these resources on the germination, survival, growth, and physiological responses of tamarind seedlings and saplings.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Water availability was critical for seed germination, but not light levels or pre-germination treatments. Light was the primary limiting factor for seedling growth. Tamarinds in high light availability grew taller, had more biomass and larger diameter, but the effect of light was modulated by water availability, indicating that there was an interaction between both resources. Water and light affected specific leaf area and leaf dry matter content but not biomass allocation, root-to-shoot ratio, or stomatal conductance. Water availability influenced sapling growth, but watering frequency did not, indicating a resilience of tamarind saplings to changes in rainfall periodicity but a sensitivity to total rainfall amounts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our study underscores the importance of considering both light and water availability in tamarind restoration efforts and contribute to understanding plant responses and trade-offs under different levels of critical resources. Our findings will inform conservation strategies to support the regeneration and long-term survival of <i>Tamarindus indica</i> in its native habitats.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555597","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":"Phylogeny does not predict the outcome of heterospecific pollen–pistil interactions in a species-rich alpine plant community","authors":"Rachel O. Cohen,&nbsp;Asstan Cisse,&nbsp;Jennifer U. Jones,&nbsp;Joseph H. Williams,&nbsp;Deren A. R. Eaton","doi":"10.1002/ajb2.70004","DOIUrl":"10.1002/ajb2.70004","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Co-occurring plant species that share generalist pollinators often exchange pollen. This heterospecific pollen transfer (HPT) impacts male and female reproductive success through pollen loss and reductions in seed set, respectively. The resulting fitness cost of HPT imposes selection on reproductive traits (e.g., floral color and shape), yet we currently lack strong predictors for the post-pollination fate of heterospecific pollen, especially within community and phylogenetic contexts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We investigated the fate of heterospecific pollen at three distinct stages of plant reproduction: (1) pollen germination on the stigma, (2) pollen tube growth in the style, and (3) fertilization of ovules. We experimentally crossed 11 naturally co-flowering species in the subalpine meadows of the Colorado Rocky Mountains, across a spectrum of phylogenetic relatedness. Using generalized linear mixed models and generalized linear models, we evaluated the effect of parental species identity and phylogenetic relatedness on pollen tube growth at each reproductive stage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found that heterospecific pollen tubes can germinate and grow within pistils at each reproductive stage, even when parental species are &gt;100 My divergent. There was no significant effect of phylogenetic distance on heterospecific pollen success, and no evidence for a mechanism that suspends heterospecific pollen germination or pollen tube growth within heterospecific stigmas or styles.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results show that even in communities where HPT is common, pre-zygotic post-pollination mechanisms do not provide strong barriers to interspecific fertilization. HPT can result in the loss of ovules even between highly diverged plant species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536575","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":"When the sand blossoms: Phylogeny, trait evolution, and geography of speciation in Linanthus","authors":"Ioana G. Anghel,&nbsp;Lydia L. Smith,&nbsp;Isaac H. Lichter-Marck,&nbsp;Felipe Zapata","doi":"10.1002/ajb2.70005","DOIUrl":"10.1002/ajb2.70005","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Understanding how plants successfully diversified in novel environments is a central question in evolutionary biology. <i>Linanthus</i> occurs in arid areas of western North America and exhibits extensive floral trait variation, multiple color polymorphisms, differences in blooming time, and variation in life history strategies. We reconstructed the evolutionary history of this genus.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We generated restriction-site associated (ddRAD) sequences for 180 individuals and target capture (TC) sequences for 63 individuals, with complete species sampling. Using maximum likelihood and pseudo-coalescent approaches, we inferred phylogenies of <i>Linanthus</i> and used them to model the evolution of phenotypic traits and investigate the genus's geographic speciation history.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Relationships are consistent and well supported with both ddRAD and TC data. Most species are monophyletic despite extensive local sympatry and range overlap, suggesting strong isolating barriers. The non-monophyly of the night-blooming and perennial species may be due to rapid speciation or cryptic diversity. Perenniality likely evolved from annuality, a rare shift in angiosperms. Night-blooming evolved three times independently. Flower color polymorphism is an evolutionarily labile trait that is likely ancestral. No single geographic mode of speciation characterizes this diversification, but most species overlap in range, which suggests that they evolved in parapatry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results illustrate the complexity of phylogenetic inference for recent radiations, even with multiple sources of genomic data and extensive sampling. This analysis provides a foundation for understanding aridity adaptations, such as evolution of flower color polymorphisms, night-blooming, and perenniality, as well as speciation mechanisms.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497682","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}