American Journal of Botany最新文献

{"title":"When the sand blossoms: Phylogeny, trait evolution, and geography of speciation in Linanthus.","authors":"Ioana G Anghel, Lydia L Smith, Isaac H Lichter-Marck, Felipe Zapata","doi":"10.1002/ajb2.70005","DOIUrl":"https://doi.org/10.1002/ajb2.70005","url":null,"abstract":"<p><strong>Premise: </strong>Understanding how plants successfully diversified in novel environments is a central question in evolutionary biology. Linanthus 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><p><strong>Methods: </strong>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 Linanthus and used them to model the evolution of phenotypic traits and investigate the genus's geographic speciation history.</p><p><strong>Results: </strong>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><p><strong>Conclusions: </strong>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>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70005"},"PeriodicalIF":2.4,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","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":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The nitrogen-fixing fern Azolla has a complex microbiome characterized by varying degrees of cophylogenetic signal.","authors":"Michael J Song, Forrest Freund, Carrie M Tribble, Erin Toffelmier, Courtney Miller, H Bradley Shaffer, Fay-Wei Li, Carl J Rothfels","doi":"10.1002/ajb2.70010","DOIUrl":"https://doi.org/10.1002/ajb2.70010","url":null,"abstract":"<p><strong>Premise: </strong>Azolla is a genus of floating ferns that has closely evolved with a vertically transmitted obligate cyanobacterium endosymbiont-Anabaena azollae-that fixes nitrogen. There are also other lesser-known Azolla symbionts whose role and mode of transmission are unknown.</p><p><strong>Methods: </strong>We sequenced 112 Azolla specimens collected across the state of California and characterized their metagenomes to identify the common bacterial endosymbionts and assess their patterns of interaction.</p><p><strong>Results: </strong>Four genera were found across all samples, establishing that multiple Azolla endosymbionts were consistently present. We found varying degrees of cophylogenetic signal across these taxa as well as varying degrees of isolation by distance and of pseudogenation, which demonstrates that multiple processes underlie how this endosymbiotic community is constituted. We also characterized the entire Azolla leaf pocket microbiome.</p><p><strong>Conclusions: </strong>These results show that the Azolla symbiotic community is complex and features members at potentially different stages of symbiosis evolution, further supporting the utility of the Azolla microcosm as a system for studying the evolution of symbioses.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70010"},"PeriodicalIF":2.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476191","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":"Female heterogamety (ZW systems) in 22% of flowering plants with sex chromosomes: Theoretical expectations and correlates.","authors":"Susanne S Renner","doi":"10.1002/ajb2.70006","DOIUrl":"https://doi.org/10.1002/ajb2.70006","url":null,"abstract":"","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70006"},"PeriodicalIF":2.4,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466745","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":"Erratum to “Neopolyploidy has variable effects on the diversity and composition of the wild strawberry microbiome”","authors":"","doi":"10.1002/ajb2.70009","DOIUrl":"10.1002/ajb2.70009","url":null,"abstract":"<p>Anneberg, T. J., N. P. Cullen, E. M. O'Neill, N. Wei, and T.-L. Ashman. 2024. Neopolyploidy has variable effects on the diversity and composition of the wild strawberry microbiome. <i>American Journal of Botany</i> 111(8): e16287. https://doi.org/10.1002/ajb2.16287</p><p>The legends for Figure 2 and Figure 3 were switched.</p><p>We apologize for this error.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439340","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":"Can biocrust moss hide from climate change? Fine-scale habitat sheltering improves summer stress resistance in Syntrichia caninervis","authors":"Theresa A. Clark,&nbsp;Alexander Russell,&nbsp;Joshua L. Greenwood,&nbsp;Dale Devitt,&nbsp;Daniel Stanton,&nbsp;Lloyd R. Stark","doi":"10.1002/ajb2.16464","DOIUrl":"10.1002/ajb2.16464","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Mosses provide many ecosystem functions and are the most vulnerable of biocrust organisms to climate change due to their sensitive water relations stressed by summer aridity. Given their small size, moss stress resistance may be more dependent on fine-scale habitat than macroclimate, but the sheltering role of habitat (i.e., habitat buffering) has never been compared to macroclimate and may have important implications for predicting critical biocrust moss refugia in changing climates.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We located three populations of a keystone biocrust moss, <i>Syntrichia caninervis</i>, spanning 1200 m of altitude, which comprised three macroclimate (elevation) zones of characterized plant communities in the Mojave Desert. We stratified 92 microsites along three aridity gradients: elevation zone, topography (aspect), and microhabitat (shrub proximity). We estimated summer photosynthetic stress (<i>F</i>_v/<i>F</i>_m) and aridity exposure (macroclimate, irradiance, and shade).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Microsite aridity exposure varied greatly, revealing exposed and buffered microhabitats at all three elevation zones. Moss stress did not differ by elevation zone despite the extensive macroclimate gradient, failing to support the high-elevation refugia hypothesis. Instead, stress was lowest on northerly-facing slopes and in microhabitats with greater shrub shading, while the importance of (and interactions between) topography, irradiance, and shade varied by elevation zone.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Fine-scale habitat structure appears physiologically more protective than high-elevation macroclimate and may protect some biocrust mosses from the brunt of climate change in widespread microrefugia throughout their current ranges. Our findings support a scale-focused vulnerability paradigm: microrefugia may be more important than macrorefugia for bolstering biocrust moss resistance to summer climate stress.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16464","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439842","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":"Corrigendum to “Inter-archipelago dispersal, anagenetic evolution, and the origin of a rare, enigmatic plant genus on a remote oceanic archipelago”","authors":"","doi":"10.1002/ajb2.70003","DOIUrl":"10.1002/ajb2.70003","url":null,"abstract":"<p>Cho M.-S., S.-H. Kim, P. Danton, S.-C. Kim, T. F. Stuessy, and D. J. Crawford. 2024. Inter-archipelago dispersal, anagenetic evolution, and the origin of a rare, enigmatic plant genus on a remote oceanic archipelago. <i>American Journal of Botany</i> 111: e16403. https://doi.org/10.1002/ajb2.16403</p><p>In the Acknowledgments section, the National Research Foundation of Korea grant number of “NRF-2019S1A63A02058027” was incorrect. The correct grant number should be: “NRF-2019S1A6A3A02058027”.</p><p>We apologize for this error.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143405381","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":"Corrigendum to “Oomycete communities in lowland tropical forest soils vary in species abundance and comprise saprophytes and pathogens of seeds and seedlings of multiple plant species”","authors":"","doi":"10.1002/ajb2.70007","DOIUrl":"10.1002/ajb2.70007","url":null,"abstract":"<p>Broders, K. D., H. D. Capador-Barreto, G. Iriarte, S. J. Wright, H. Espinosa, M. Baur, M. A. Lemus-Peralta, E. Rojas, and E. R. Spear. 2024. Oomycete communities in lowland tropical forest soils vary in species abundance and comprise saprophytes and pathogens of seeds and seedlings of multiple plant species. <i>American Journal of Botany</i> e16425. https://doi.org/10.1002/ajb2.16425</p><p>In the Acknowledgments section, we forgot to list one of the grants used to support this research. The following sentence should be added to the end of the acknowledgments paragraph: “This work was also funded by Grant No. 2017044 from the United States - Israel Binational Science Foundation (BSF), Jerusalem, Israel, to S.J.W and H.E.”</p><p>We apologize for this error.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143397784","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":"Herbivory exacerbates pollen limitation by isolating unconsumed plants from prospective mates","authors":"Jared J. Beck,&nbsp;Stuart Wagenius","doi":"10.1002/ajb2.70002","DOIUrl":"10.1002/ajb2.70002","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Herbivores directly influence plant reproduction by damaging reproductive tissue which reduces seed production in consumed plants. Consumption of reproductive tissue may also indirectly depress reproduction in unconsumed plants by isolating unconsumed individuals from prospective mates and reducing pollination. However, empirical support for such hypothesized indirect effects remains limited.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To investigate potential indirect effects of herbivory on mating opportunities and pollination, we quantified spatial patterns of white-tailed deer (<i>Odocoileus virginianus</i>) herbivory and reproductive outcomes in <i>Lilium philadelphicum</i> (Liliaceae). We mapped 708 flowering plants, monitored deer herbivory, and examined how distance to prospective mates influenced rates of ovule fertilization, a proxy for pollen receipt.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Most flowering <i>L. philadelphicum</i> plants (83%) failed to produce seed. Deer consumption of flowers prevented seed production in 35% of individuals. The probability of deer herbivory declined with distance to flowering conspecifics. Sixty-five percent of the remaining, unconsumed plants failed to produce seed due to apparent pollen limitation. While ovule fertilization rates declined with multiple predictors quantifying distances to flowering conspecifics, isolation metrics that excluded plants consumed by deer significantly improved predictions of ovule fertilization.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results offer empirical support for the hypothesis that herbivory reduces pollination and seed production in unconsumed plants by altering spatial mating opportunities. This feedback between deer herbivory and distance-dependent pollination contributes to widespread reproductive failure in <i>L. philadelphicum</i>, though the extent to which deer reduce seed production varies with plant isolation. Herbivory may exacerbate pollen limitation in other species by isolating unconsumed plants from prospective mates.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143397785","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":"Reconstructing the introduction history of the invasive grass Taeniatherum caput-medusae subsp. asperum in the western United States: Low within-population genetic diversity does not preclude invasion","authors":"Dean R. Marsh,&nbsp;Lynell Deines,&nbsp;Joseph H. Rausch,&nbsp;Yves Tindon,&nbsp;René F. H. Sforza,&nbsp;Anthony E. Melton,&nbsp;Stephen J. Novak","doi":"10.1002/ajb2.70001","DOIUrl":"10.1002/ajb2.70001","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>One of the main drivers of global change is biotic exchange, which leads to biological invasions. The genetic diversity and structure of invasive populations is influenced by multiple factors, most notably the details of a species' introduction, its pattern of range expansion, and its mating system. <i>Taeniatherum caput</i>-<i>medusae</i> subsp. <i>asperum</i> is a primarily self-pollinating, invasive, annual grass of the western United States (US).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using historical information (herbarium specimens and published reports) and genetic (allozyme) data, we reconstructed the introduction history and pattern of range expansion of <i>T</i>. <i>caput</i>-<i>medusae</i> subsp. <i>asperum</i> in its invasive range.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Herbarium collection data and published reports indicate that the grass was first collected near Roseburg, Oregon, in 1884 and then at Steptoe Butte, Washington, in 1901. Genetic analysis of 46 invasive populations of <i>T</i>. <i>caput</i>-<i>medusae</i> subsp. <i>asperum</i> detected seven homozygous multilocus genotypes (MLGs) across the western US. Several MLGs were found in localities associated with early collection sites. Only three of 1700 individuals we analyzed were heterozygous. Thus, high rates of self-pollination likely preserved the MLGs introduced into the western US and contributed to our ability to reconstruct the introduction history of this grass.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our data are consistent with the pattern associated with multiple introductions and local or regional range expansion. Despite multiple introductions, invasive populations of <i>T</i>. <i>caput</i>-<i>medusae</i> subsp. <i>asperum</i> exhibit relatively low within-population genetic diversity (i.e., invasive populations possess low evolutionary potential). Apparently, low within-population genetic diversity does not preclude the invasion of this grass in the western US.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143397787","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 influence of elevation on genetic structure and variability in a wetland crucifer of the Rocky Mountains","authors":"Shelby L. Tisinai,&nbsp;Jeremiah W. Busch","doi":"10.1002/ajb2.16467","DOIUrl":"10.1002/ajb2.16467","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>In mountain ecosystems, environmental conditions (e.g., temperature, ultraviolet radiation) covary with elevation, potentially limiting gene flow over steep gradients. We hypothesized that, (1) due to stark elevational differences in environmental factors, populations from dissimilar elevations (e.g., montane versus alpine) are more strongly differentiated than populations from similar elevations; (2) patterns of migration reflect downslope dispersal more than upslope dispersal; and (3) alpine populations at the cold edge show evidence of expansion, while montane populations at the warm edge have declined.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>DNA polymorphisms in whole-genome sequences were studied from 6–10 genotypes each in populations of <i>Cardamine cordifolia</i> found at three montane sites (ranging from 2200 to 2800 m a.s.l.) and three alpine sites (ranging from 3000 to 3500 m a.s.l.). Statistical analyses assessed patterns of population structure, genetic diversity, migration, and historical demography since the Pleistocene.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Populations maintained very high levels of nucleotide diversity (π range: 0.062–0.071) and were weakly differentiated (pairwise <i>F</i>_ST = 0.027) on average. Migration among alpine populations was also inferred, with no directionality of migration across elevation bands. Demographic inference suggests that both montane and alpine populations have declined in size since the Pleistocene.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Environmental differences across elevation represent diffuse barriers to gene flow. Recent polyploidy and clonal reproduction likely explain excess heterozygosity and high nucleotide diversity within populations. The genetic similarity of populations across elevation suggests highly connected refugia during the Pleistocene; such results may indicate that montane and alpine populations will respond similarly to changing environmental conditions associated with climate change.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143254510","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}