American Journal of Botany最新文献

{"title":"Fight fire with food forests: Assessing flammability of tropical crop plant species to design fire-smart agroforestry systems.","authors":"Ashley S Pacheco, Hannah D Goodman, Lexi Hankenson, Alejandro Ortiz, Henry M Marinace, Joseph J Fisk, Emily A Bischoff, Victoria F Holman, Sophia M Love, Deborah M G Apgaua, David Y P Tng","doi":"10.1002/ajb2.70075","DOIUrl":"https://doi.org/10.1002/ajb2.70075","url":null,"abstract":"<p><strong>Premise: </strong>The increased frequency of droughts and wildfires in recent decades poses a significant risk to agricultural lands and private property. Given the negative impact of fires on food production and associated livelihoods, it is crucial to assess the flammability of crop species and find ways of mitigating risk of fire in agricultural lands.</p><p><strong>Methods: </strong>We quantified the shoot-level flammability of 65 tropical species of fiber, food, and spice crops by assessing maximum temperature, burn time, and burnt biomass and assessed key leaf traits from a subset of these species to assess how specific leaf area (SLA), leaf area (LA), and leaf dry mass to fresh mass ratio (DM:FM) influences these flammability measures.</p><p><strong>Results: </strong>Groundcover, shrubs, and vines were generally less flammable than canopy and subcanopy plants. DM:FM was a consistent and significant predictor of all three flammability measures regardless of plant life form.</p><p><strong>Conclusions: </strong>Our results equip farmers and policymakers with information to construct agricultural landscapes that are more fire resilient and options for pursuing nature-based solutions to mitigate fire risk, such as planting green firebreaks with fire-retardant species.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70075"},"PeriodicalIF":2.4,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658109","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":"Plastomic studies inform the mechanisms of edaphic adaptation in North American species in the tribe Thelypodieae (Brassicaceae)","authors":"Kasuni C. Daundasekara,&nbsp;Elyssa R. Garza,&nbsp;Alan E. Pepper","doi":"10.1002/ajb2.70071","DOIUrl":"10.1002/ajb2.70071","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Adaptation to edaphic environments is vital for plant survival. The tribe Thelypodieae (Brassicaceae) thrives in diverse edaphic conditions, including harsh serpentine soils. A robust phylogeny is essential to understanding the edaphic evolution in this tribe but is challenging to obtain due to incomplete lineage sorting, hybridization, and gene duplication. This study uses organellar and nuclear genome analyses to provide new phylogenetic insights into Thelypodieae, supporting future research on edaphic adaptation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We conducted phylogenomic analyses of 28 representative species within the tribe Thelypodieae from western North America and reconstructed phylogenies using plastid, mitochondrial, and selected nuclear loci. Additionally, using the maximum likelihood method CodeML, we identified potential targets of positive selection within the plastid genome.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We obtained a well-resolved phylogenetic tree of the representative species using the complete organellar genomes. Incongruence between organellar and nuclear phylogenies uncovered a history of hybridization within this group. The time-calibrated evolutionary model indicates that Thelypodieae evolved through hybridization and adaptive radiation, driven by climatic and topographic changes since the Miocene. Through comparisons of plastid genomes, we identified specific plastid genes (<i>atpB</i>, <i>ndhC</i>, <i>ndhF</i>, <i>cemA</i>, <i>rps3</i>, <i>rbcL</i>, <i>ycf2</i>, <i>clp1</i>, and <i>matK</i>) that displayed evidence of adaptive evolution, potentially in response to edaphic and climatic challenges.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Through a multigenomic approach, we obtained novel insights into the evolutionary dynamics and adaptive mechanisms in the tribe Thelypodieae that contribute to a clearer understanding of the mechanisms of evolution in a clade of plants that shows adaptation to a range of environments.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70071","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144625282","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":"Floral shape and color impact heat accumulation and thermal stability of the floral microenvironment in a subalpine meadow.","authors":"Jennifer S Apland, Katherine E Riddle, Matthew H Koski","doi":"10.1002/ajb2.70070","DOIUrl":"https://doi.org/10.1002/ajb2.70070","url":null,"abstract":"<p><strong>Premise: </strong>The floral thermal microenvironment impacts plant reproduction through its effects on gametophyte performance and plant-pollinator interactions. Color and shape are axes of floral variation that may mediate floral temperature because they affect the absorption and reflection of solar radiation, but their interactive effects are unclear. Additionally, near infrared (NIR) reflectance is important for organismal temperature, but the contribution of petal NIR reflectance to floral temperature has not been assessed.</p><p><strong>Methods: </strong>In a subalpine meadow during peak solar radiation, we continuously tracked temperature of the floral microenvironment and air temperature outside of flowers for species that differed in floral shape and dominant floral color (yellow vs. anthocyanic [pink, blue, red]). We related shape, color, surface area, and UV-NIR petal reflectance to floral temperature metrics.</p><p><strong>Results: </strong>Flowers with exposed reproductive structures (\"open\") warmed more than those with concealed reproductive structures (\"closed\"), and this effect was strongest for yellow flowers. Closed flowers were more thermally stable than open flowers regardless of color. Open flowers with larger surface area also warmed more. NIR reflectance (700-900 nm) was strongly correlated with visible reflectance (500-700 nm), so its effect on floral temperature could not be isolated. However, closed flowers with stronger reflectance from 500 to 900 nm were cooler and more thermally stable.</p><p><strong>Conclusions: </strong>Our results show that floral color, reflectance, and shape interact to influence the temperature of the floral microenvironment of our focal taxa. They provide a predictive framework for how floral traits may change across space and time in response to temperature variation.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70070"},"PeriodicalIF":2.4,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144625215","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":"Toward a macroevolutionary understanding of live-leaf flammability in plant species of fire-prone forests.","authors":"Brad R Murray, Lyndle K Hardstaff, Megan L Murray, Zoe A Xirocostas","doi":"10.1002/ajb2.70073","DOIUrl":"https://doi.org/10.1002/ajb2.70073","url":null,"abstract":"<p><strong>Premise: </strong>The flammability of live leaves in canopies varies considerably among plant species. Identifying macroevolutionary processes that shape variation in leaf flammability contributes to an understanding of the phylogenetic underpinnings of wildfire dynamics.</p><p><strong>Methods: </strong>We used a phylogenetic comparative approach to examine the macroevolution of live-leaf flammability in 75 plant species of fire-prone dry sclerophyll forests in eastern Australia. We estimated phylogenetic signal in leaf flammability, fitted a series of evolutionary models to test macroevolutionary hypotheses about leaf flammability, and assessed evolutionary correlations between leaf flammability and leaf water content (LWC), leaf mass per area (LMA), leaf area (LA), plant growth form, and fire response strategy.</p><p><strong>Results: </strong>We detected weak phylogenetic signal, indicating that leaf flammability exhibited greater variation among closely related species than would be expected under phylogenetic conservatism. The evolution of leaf flammability was equally well described by an Ornstein-Uhlenbeck model and a Pagel's δ model, implying weak stabilizing selection and an acceleration in leaf flammability evolution over time. We found significant evolutionary correlations such that high leaf flammability was related to low LWC, low LMA, and large LA.</p><p><strong>Conclusions: </strong>Our results show that live-leaf flammability is an evolutionarily labile trait in plant species of fire-prone forests. We suggest that the evolution of the three leaf traits in response to prevailing environmental conditions (such as LWC to water availability, LA to light capture, and LMA to herbivore defence) provide antagonistic selective forces that produce a macroevolutionary pattern of weak stabilising selection on leaf flammability.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70073"},"PeriodicalIF":2.4,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144607166","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":"Genomic resources for crop wild relatives are critical for perennial fruit breeding and conservation","authors":"Zoë Migicovsky","doi":"10.1002/ajb2.70068","DOIUrl":"10.1002/ajb2.70068","url":null,"abstract":"<p>Many perennial fruit crops are clonally propagated, resulting in uniform fruit quality but increasing vulnerability to pests, diseases, and climate change. In contrast, closely related crop wild relatives (CWRs) continue to evolve in response to these pressures and are a valuable source of adaptive traits. Despite their potential, CWRs are underutilized in perennial fruit breeding. Efficient and accurate introgression of traits from CWRs during perennial fruit breeding will require the use of genomics. Genomics-assisted breeding begins with genetic mapping, such as genome-wide association studies, to identify markers predictive of traits of interest. For diverse species such as CWRs, a pangenomic approach that incorporates multiple species as a reference is often necessary. Continued use of CWRs in fruit breeding also depends on their conservation, both in situ (in natural habitats) and ex situ (off-site). Ex situ collections can also be used for genetic mapping, further supporting genomics-assisted plant breeding efforts. Ultimately, breeding and conservation of perennial fruit crops are complementary goals that benefit from the development and application of genomic resources.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144590272","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":"When numbers matter: Rethinking the role of gene duplication on short evolutionary timescales","authors":"Freja Lindstedt,&nbsp;Qiujie Zhou,&nbsp;Pascal Milesi","doi":"10.1002/ajb2.70072","DOIUrl":"10.1002/ajb2.70072","url":null,"abstract":"&lt;p&gt;The potential roles of genomic structural variations (SVs) in the control of phenotypic traits and in evolution were suggested as early as the 20th century. However, they were then overshadowed by the emphasis put on single nucleotide polymorphisms (SNPs). Recently, SVs have received renewed attention in evolutionary research due to advancements in sequencing technologies and analytical methods.&lt;/p&gt;&lt;p&gt;At the macroevolutionary scale, plant genomes tend to evolve faster than those of other eukaryotes, due to the prevalence of whole genome duplication events (Wendel et al., &lt;span&gt;2016&lt;/span&gt;). Unlike other types of structural variants, such as inversions, copy number variations (CNVs) result from unbalanced mutations that affect the dosage, or amount, of a DNA sequence. When genes are involved, the number of copies of a gene varies from one individual to another. In plants, gene copy number variations (gCNVs) are likely to be abundant due to events such as mating system shifts (the efficacy of purifying selection is reduced in selfing species), hybridization and subsequent genome rearrangements, and whole genome duplications followed by biased retention (Panchy et al., &lt;span&gt;2016&lt;/span&gt;; Wendel et al., &lt;span&gt;2016&lt;/span&gt;; Van de Peer et al., &lt;span&gt;2017&lt;/span&gt;). For example, in &lt;i&gt;Arabidopsis thaliana&lt;/i&gt; (L.) Heynh. (Brassicaceae) 10 to 18% of all genes display CNVs (Zmienko et al., &lt;span&gt;2020&lt;/span&gt;; Jaegle et al., &lt;span&gt;2023&lt;/span&gt;). In the genus &lt;i&gt;Picea&lt;/i&gt; Mill. (Pinaceae), at least 10% of the protein-coding genes display CNVs (&lt;i&gt;P. abies&lt;/i&gt; (L.) H. Karst and &lt;i&gt;P. obovata&lt;/i&gt; Ledeb., Q. Zhou et al., &lt;span&gt;2025&lt;/span&gt;; and &lt;i&gt;P. glauca&lt;/i&gt; (Moench) Voss and &lt;i&gt;P. mariana&lt;/i&gt; (Mill.) Britton, Sterns &amp; Poggenburg, Prunier et al., &lt;span&gt;2017&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;Gene duplications have primarily been studied for their roles in long-term evolution. However, a change in gene dosage usually results in a change in the amount of gene products, such as RNA or proteins (e.g., Shao et al., &lt;span&gt;2019&lt;/span&gt;). Therefore, gCNVs have a unique, multiallelic, and quantitative nature. Fully apprehending their role in short-term evolutionary processes requires studying them as quantitative genotypes rather than in a presence/absence (or biallelic) manner, as is most often done (Figure 1, top panel). Unlike SNPs, the accuracy and resolution of gCNV genotyping are usually dependent on the platform used. From short-read sequencing data, one can use biased allelic ratios (Figure 2A) and changes in the depth of coverage (DoC) caused by the mis-mapping of reads from duplicated regions to the same locus in the reference genome to identify CNVs (Figure 2). However, short reads often fail to capture the underlying genetic structure of gCNVs, and changes in DoC can only be interpreted as relative copy numbers across homologous chromosomes (Figure 1, middle panel). Long-read sequencing is a promising alternative that allows for the phasing of the various alleles to obtain","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144599148","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":"Patterns of within- and among-plant variation in nectar production in the beetle-pollinated Amianthium muscaetoxicum","authors":"Sarah J. McPeek,&nbsp;Connor L. Erwin,&nbsp;Edmund D. Brodie III","doi":"10.1002/ajb2.70069","DOIUrl":"10.1002/ajb2.70069","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Plant interactions with different pollinator species have shaped the evolution of remarkable diverse nectar production, presentation, and composition traits across the angiosperms. These traits can allow plants to manipulate and reward the behaviors of specific pollinators to enhance pollen donation and receipt with some precision. One group of animal-pollinated flowers notably lack characterizations of nectar trait diversity: plants that are pollinated by nectar-feeding beetles.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In a series of studies, we characterized variation in nectar traits within flowers, within plants, within populations and investigated the behavior of beetles feeding on nectar in a single population of the beetle-pollinated perennial monocot, <i>Amianthium muscaetoxicum</i> (Melanthiaceae).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>At the flower level, nectar accumulated throughout an individual flower's lifetime, peaking at anthesis and ceasing thereafter. Lifetime nectar production of flowers on a plant was highly consistent. At the population level, plants had high among-individual variation in nectar volume and nectar sugar concentration. Feeding experiments with a primary beetle pollinator further revealed that beetles spent significantly more time interacting with flowers with higher nectar volumes, but not flowers with higher sugar concentrations or total sugar content.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our findings begin to shed light on the mutualistic interaction between <i>Amianthium</i> and its beetle pollinators and on the commonalities and differences between beetles and other species of nectar-feeding pollinators.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70069","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144582814","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":"Deciphering fire tolerance of trees at the Amazonia-Cerrado transition by trait-based approach: Implications from species to communities.","authors":"Wesley Jonatar A Cruz, Manoela S Machado, Francisco Navarro-Rosales, Maria Antonia Carniello, Marcelo Leandro F Andrade, Flávio C Oliveira, Immaculada Oliveras Menor","doi":"10.1002/ajb2.70066","DOIUrl":"10.1002/ajb2.70066","url":null,"abstract":"<p><strong>Premise: </strong>Understanding how fire impacts trees is essential for predicting the effects of novel fire regimes on plant diversity in the transition between the world's two most diverse biomes, the Cerrado and the Amazonia. Here we addressed knowledge gaps regarding physiological damage and mortality in transitional species within fire-prone ecosystems.</p><p><strong>Methods: </strong>In a manipulative fire experiment, we burned a transitional woodland savanna for six consecutive years after it had been fire-excluded for 33 years. We classified the most abundant tree species according to their fire tolerance and examined the relationship between fire tolerance and key morphological and ecophysiological functional traits. These traits were related to leaf economics spectrum, bark investment, wood density, flammability, and physiological drought tolerance.</p><p><strong>Results: </strong>Species had three main fire tolerance strategies, reflected in their investment in the outer and inner bark, wood density in branches and the main trunk, changes in leaf water potential, and water and dry matter ratios in leaves. The inner and outer bark and the level of protection of the sprouting buds better explained tree mortality and topkill. Under very frequent fires, fire-sensitive species had the highest mortality rates and fire-thrivers became the most abundant species.</p><p><strong>Conclusions: </strong>Transitional tree species had different response strategies to fire based on their tolerance, which directly influences their survival and the overall structure of the community. Our findings suggest likely shifts in tree community structure in response to novel fire regimes.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70066"},"PeriodicalIF":2.4,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551735","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":"The interplay among space, environment, and gene flow drives genetic differentiation in endemic Baja California Agave sobria subspecies","authors":"Anastasia Klimova,&nbsp;Jesús Gutiérrez Rivera,&nbsp;Oscar E. Juárez,&nbsp;Alfredo Ortega Rubio,&nbsp;Luis E. Eguiarte","doi":"10.1002/ajb2.70062","DOIUrl":"10.1002/ajb2.70062","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Research on neutral and adaptive processes that lead to the divergence of species and populations is a crucial component in evolutionary and conservation genetics. <i>Agave sobria</i> is an endemic group of subspecies scattered on canyons along a latitudinal gradient and distinct environments of the Baja California Peninsula, Mexico. <i>Agave sobria</i> represents a unique opportunity to study the process of genetic differentiation in a highly heterogeneous environment.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using genotyping-by-sequencing, we genotyped 8453 single-nucleotide polymorphisms (SNPs) in all <i>A. sobria</i> subspecies, including 19 <i>A. sobria</i> and three closely related <i>A. cerulata</i> ssp. <i>subcerulata</i> populations. We assessed neutral genetic structure and diversity at both the interspecific and intraspecific levels, evaluated the amount and direction of gene flow, and identified putatively adaptive SNPs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found low support for the currently recognized subspecies. We detected neutral (i.e., isolation by distance) and adaptive divergence linked to eco-geographic characteristics of the habitat. High genetic connectivity indicated that gene flow between central and northern populations may have homogenizing effects preventing population differentiation. For the southernmost <i>A. sobria</i> ssp. <i>frailensis</i>, temperature and geographic isolation appear to be the main drivers of adaptive differentiation, with outlier SNPs located in coding regions involved in response to abiotic stress and immunology.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>In <i>A. sobria</i>, environmental isolation and geographic gradients affect the genetic structure, creating opportunities for local adaptation. Our results emphasize the importance of including neutral and adaptive perspectives, the combination of which allows a better understanding of the complexity of the processes that lead to population differentiation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551736","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":"Floral scent of artificial hybrids between two Schiedea species that share a moth pollinator","authors":"John M. Powers,&nbsp;Stephen G. Weller,&nbsp;Ann K. Sakai,&nbsp;Diane R. Campbell","doi":"10.1002/ajb2.70065","DOIUrl":"10.1002/ajb2.70065","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>In flowering plants, pollinators' ability to recognize chemical displays of hybrids may erode reproductive barriers. Hybrids may produce novel or altered floral scent blends that are unattractive, or scents similar to either parent that remain attractive and promote backcrossing. We characterized the floral scent of hybrids of sympatric species with a shared pollinator and tested whether scent is sufficient for pollinator attraction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Floral volatiles of artificial F₁ hybrids between Hawaiian <i>Schiedea kaalae</i> and <i>S. hookeri</i> (Caryophyllaceae) were characterized by dynamic headspace sampling and GC-MS. Behavioral choice tests with the native moth <i>Pseudoschrankia brevipalpis</i> measured the effect of adding <i>S. kaalae</i> scent (with flowers bagged to remove visual cues) to inflorescences of relatively unattractive wind-pollinated relatives (<i>S. kealiae</i> and <i>S. globosa</i>) from the same island.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Most hybrids produced a combination of the distinct sets of floral volatiles from each parent at rates of emission that often differed from the expectation under completely additive inheritance. Floral scent did not depend on cross direction, and no novel compounds were detected in hybrids. <i>Pseudoschrankia brevipalpis</i> preferred inflorescences of <i>S. globosa</i> and <i>S. kealiae</i> that were augmented with the scent of hidden <i>S. kaalae</i> flowers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Intermediate hybrid floral scent blends could potentially attract moths if they do not rely on precise compound ratios. Moth attraction to the floral scent of <i>S. kaalae</i> flowers indicates that moths can discriminate the floral scent of this species against a background of volatiles and visual cues from wind-pollinated relatives, showing the importance of scent variation in this genus.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526116","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}