American Journal of Botany最新文献

{"title":"Why are triploid quaking aspen (Populus tremuloides) common?","authors":"Benjamin Wong Blonder","doi":"10.1002/ajb2.16325","DOIUrl":"10.1002/ajb2.16325","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Quaking aspen is a clonal tree species that has mixed ploidy, often with high relative abundance of both diploids and triploids but no haploids or tetraploids. Triploids typically have low fertility, leaving their occurrence apparently unlikely from an evolutionary perspective, unless they provide a “triploid bridge” to generating higher-fitness tetraploids—which are not observed in this species. This study focused on how triploidy can be maintained in quaking aspen.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A computational model was used to simulate gamete production, sexual reproduction, asexual reproduction, parent survival, and offspring survival in a population. All parameters were assumed to be cytotype-dependent and environment-independent. Sampling methods were used to identify parameter combinations consistent with observed cytotype frequencies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Many processes and parameter values were sufficient to yield a moderate frequency of triploids, and very few were necessary. The most plausible route involved higher triploid survival at the parent or offspring stage and limited unreduced gamete production by either diploid or triploid parents. Triploid fertility was helpful but not necessary.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The coexistence of diploids and triploids in quaking aspen is statistically likely and promoted by the existence of commonly observed, long-lived triploid clones. However, other mechanisms not captured by the model related to environmental variation could also occur. Further empirical data or more complex but difficult-to-parameterize models are needed to gain further insight.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140841841","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":"Genome size variation in Cape schoenoid sedges (Schoeneae) and its ecophysiological consequences","authors":"Ruan van Mazijk,&nbsp;Adam G. West,&nbsp;G. Anthony Verboom,&nbsp;Tammy L. Elliott,&nbsp;Petr Bureš,&nbsp;A. Muthama Muasya","doi":"10.1002/ajb2.16315","DOIUrl":"10.1002/ajb2.16315","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Increases in genome size in plants—often associated with larger, low-density stomata and greater water-use efficiency (WUE)—could affect plant ecophysiological and hydraulic function. Variation in plant genome size is often due to polyploidy, having occurred repeatedly in the austral sedge genus <i>Schoenus</i> in the Cape Floristic Region (CFR), while species in the other major schoenoid genus in the region, <i>Tetraria</i>, have smaller genomes. Comparing these genera is useful as they co-occur at the landscape level, under broadly similar bioclimatic conditions. We hypothesized that CFR <i>Schoenus</i> have greater WUE, with lower maximum stomatal conductance (<i>g</i>_wmax) imposed by larger, less-dense stomata.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We investigated relationships between genome size and stomatal parameters in a phylogenetic context, reconstructing a phylogeny of CFR-occurring Schoeneae (Cyperaceae). Species’ stomatal and functional traits were measured from field-collected and herbarium specimens. Carbon stable isotopes were used as an index of WUE. Genome size was derived from flow-cytometric measurements of leafy shoots.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Evolutionary regressions demonstrated that stomatal size and density covary with genome size, positively and negatively, respectively, with genome size explaining 72–75% of the variation in stomatal size. Larger-genomed species had lower <i>g</i>_wmax and C:N ratios, particularly in culms.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We interpret differences in vegetative physiology between the genera as evidence of more-conservative strategies in CFR <i>Schoenus</i> compared to the more-acquisitive <i>Tetraria</i>. Because <i>Schoenus</i> have smaller, reduced leaves, they likely rely more on culm photosynthesis than <i>Tetraria</i>. Across the CFR Schoeneae, ecophysiology correlates with genome size, but confounding sources of trait variation limit inferences about causal relationships between traits.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16315","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140832389","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 tiny drivers behind plant ecology and evolution","authors":"Jennifer A. Lau,&nbsp;Lana G. Bolin","doi":"10.1002/ajb2.16324","DOIUrl":"10.1002/ajb2.16324","url":null,"abstract":"<p>Plants are the homes and hosts of a vast diversity of microbiota. These microbes help plants access nutrients, mimic plant hormones to alter plant traits, synthesize new compounds that help plants defend against enemies, and so much more. Their pervasiveness and power means that they also likely alter many of the phenomena long studied by plant ecologists and evolutionary biologists from plant coexistence to speciation. Ignoring microbes means that we may be under- or overestimating the magnitude of or misidentifying the proximal causes of several common outcomes in plant ecology and evolution. Yet, accounting for these cryptic copilots also is not easy because not only the presence of microbes, but also their community composition and evolutionary histories determine their effects. Here we describe the outsized roles microbial communities may play in three fundamental areas of plant ecology and evolution: maternal effects, phenotypic plasticity, and natural selection. These three topic areas are not exhaustive, and microorganisms likely influence many more study areas in plant biology (e.g., plant coexistence [Bever et al., <span>1997</span>], the expression of genetic variation [O'Brien et al., <span>2019</span>], and perhaps even reproductive isolation and speciation as observed in insect systems [Tiffin et al., <span>2001</span>]). However, our goal is to demonstrate some of the potential consequences of ignoring these microscopic millions and to convince plant ecologists and evolutionary biologists that considering microbial effects in our experiments may improve our understanding of how things actually work in a natural world that is dominated not by plants and plant genes but by the microbes associating with them.</p><p>Maternal effects in plants have been recognized for over a century (Roach and Wulff, <span>1987</span>), and plants have been relying on maternally inherited microbial symbionts for plant defense, abiotic stress tolerance, and even the very basics of plant function (e.g., plant capture of microbial ancestors of chloroplasts) since their earliest origins (Sagan, <span>1967</span>). Yet, we are only now beginning to investigate the roles that diverse soil and foliar microbial communities play in promoting adaptive maternal environmental effects.</p><p>Maternal environmental effects result when the maternal environment influences offspring phenotype. Moms often do this by altering resource provisioning to offspring (e.g., seed mass) or altering the chemical composition or epigenetic profile of seeds (e.g., transmission of mRNA or proteins or DNA methylation). Because soil and foliar microbes affect plant growth and can mimic and alter plant signaling pathways, they may also affect maternal resource availability and/or alter chemical signals to offspring (Figure 1a). In this way, microbial communities may function much like any other environmental factor. However, microbial communities may be even more likely to cause matern","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16324","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140652901","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":"Reconstruction of an enigmatic Pennsylvanian cone reveals a relationship to Sphenophyllales","authors":"Michael P. D'Antonio,&nbsp;Carol L. Hotton,&nbsp;Selena Y. Smith,&nbsp;Peter R. Crane,&nbsp;Fabiany Herrera","doi":"10.1002/ajb2.16321","DOIUrl":"https://doi.org/10.1002/ajb2.16321","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>We studied the 3D morphology of a small, well-preserved cone from the Pennsylvanian Mazon Creek Lagerstätte to characterize its structure and determine its systematic affinity. Previously tentatively assigned to the enigmatic <i>Tetraphyllostrobus</i>, we show that it differs in key respects from that genus as described.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We systematically compared the new fossil with relevant Paleozoic cone genera and employed advanced imaging techniques, including scanning electron microscopy, Airyscan confocal super-resolution microscopy, optical microscopy, and X-ray microcomputed tomography to visualize and reconstruct the fossil cone in 3D.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The analyses demonstrate unequivocally that the sporophylls of the new Mazon Creek cone are arranged in whorls of six and have characters typical of Sphenophyllales, including epidermal cells with undulatory margins and in situ spores assignable to <i>Columinisporites</i>. The combination of characters, including sporophyll arrangement, anatomy, and spore type, supports the establishment of <i>Hexaphyllostrobus kostorhysii</i> gen. et sp. nov. within Sphenophyllales. Furthermore, we show that <i>Tetraphyllostrobus</i>, although originally described as possessing smooth monolete spores, actually possesses <i>Columinisporites</i>-type spores, indicating that it, too, was most likely a sphenophyll.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The recognition of <i>Hexaphyllostrobus</i> contributes to our knowledge of Pennsylvanian sphenophyll diversity, and in particular increases the number of species with in situ <i>Columinisporites</i>-type spores. Attribution of <i>Hexaphyllostrobus</i> to Sphenophyllales calls into question current interpretations of <i>Tetraphyllostrobus</i> suggesting that future research on better-preserved macrofossil material may demonstrate a sphenophyllalean relationship.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140648167","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 definition and distribution of spring ephemeral wildflowers in eastern North America","authors":"Abby J. Yancy,&nbsp;Benjamin R. Lee,&nbsp;Sara E. Kuebbing,&nbsp;Howard S. Neufeld,&nbsp;Michelle Elise Spicer,&nbsp;J. Mason Heberling","doi":"10.1002/ajb2.16323","DOIUrl":"10.1002/ajb2.16323","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The herbaceous layer accounts for the majority of plant biodiversity in eastern North American forests, encompassing substantial variation in life history strategy and function. One group of early-season herbaceous understory species, colloquially referred to as spring ephemeral wildflowers, are ecologically and culturally important, but little is known about the prevalence and biogeographic patterns of the spring ephemeral strategy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used observations collected by the Global Biodiversity Information Facility (GBIF) to quantify the ephemerality of 559 understory forb species across eastern North America and classify them according to a continuous ephemerality index (ranging from 0 = never ephemeral to 1 = always ephemeral). We then used this information to model where ephemeral forbs were most common across the landscape with the goal of identifying geographic and environmental drivers important to their distributions and ranges.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Only 3.4% of all understory wildflower species were spring ephemerals in all parts of their range, and 18.4% (103 species) were ephemeral in at least part of their range. Spring ephemerals peaked in absolute species richness and relative proportion at mid latitudes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Spring ephemeral phenology is an important shade-avoidance strategy for a large segment of the total understory species in temperate deciduous forests. In North America, the strategy is relatively most important for forest understories at mid latitudes. The definitions of spring ephemerality we provide here serve as an important ecological context for conservation priorities and to evaluate responses of this biodiverse group to future environmental change.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140665760","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":"Quantifying soil microbial effects on plant species coexistence: A conceptual synthesis","authors":"Gaurav S. Kandlikar","doi":"10.1002/ajb2.16316","DOIUrl":"https://doi.org/10.1002/ajb2.16316","url":null,"abstract":"<p>Soil microorganisms play a critical role in shaping the biodiversity dynamics of plant communities. These microbial effects can arise through direct mediation of plant fitness by pathogens and mutualists, and over the past two decades, numerous studies have shined a spotlight on the role of dynamic feedbacks between plants and soil microorganisms as key determinants of plant species coexistence. Such feedbacks occur when plants modify the composition of the soil community, which in turn affects plant performance. Stimulated by a theoretical model developed in the 1990s, a bulk of the empirical evidence for microbial controls over plant coexistence comes from experiments that quantify plant growth in soil communities that were previously conditioned by conspecific or heterospecific plants. These studies have revealed that soil microbes can generate strong negative to positive frequency-dependent dynamics among plants. Even as soil microbes have become recognized as a key player in determining plant coexistence outcomes, the past few years have seen a renewed interest in expanding the conceptual foundations of this field. New results include re-interpretations of key metrics from classic two-species models, extensions of plant–soil feedback theory to multispecies communities, and frameworks to integrate plant–soil feedbacks with processes like intra- and interspecific competition. Here, I review the implications of theoretical developments for interpreting existing empirical results and highlight proposed analyses and designs for future experiments that can enable a more complete understanding of microbial regulation of plant community dynamics.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140648166","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":"Rethinking pathways to the dioecy–polyploidy association: Genera with many dioecious species have fewer polyploids","authors":"Wilhelm H. A. Osterman,&nbsp;Adrian Hill,&nbsp;James G. Hagan,&nbsp;Jeannette Whitton,&nbsp;Christine D. Bacon,&nbsp;Anne D. Bjorkman","doi":"10.1002/ajb2.16318","DOIUrl":"10.1002/ajb2.16318","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Numerous studies have found a positive association between dioecy and polyploidy; however, this association presents a theoretical conflict: While polyploids are predicted to benefit from self-reproduction for successful establishment, dioecious species cannot self-reproduce. We propose a theoretical framework to resolve this apparent conflict. We hypothesize that the inability of dioecious species to self-reproduce hinders their establishment as polyploids. We therefore expect that genera with many dioecious species have fewer polyploids, leading to a negative association between polyploidy and dioecy across genera.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used three publicly available databases to determine ploidy and sexual systems for 131 genera and 546 species. We quantified (1) the relationship between the frequency of polyploid species and the frequency of dioecious species across genera, and (2) the proportion of polyploids with hermaphroditism and dioecy across species, adjusting for phylogenetic history.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Across genera, we found a negative relationship between the proportion of polyploids and the proportion of dioecious species, a consistent trend across clades. Across all species, we found that sexual system (dioecious or not) was not associated with polyploidy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Polyploids are rare in genera in which the majority of species are dioecious, consistent with the theory that self-reproduction favors polyploid establishment. The low frequency of polyploidy among dioecious species indicates the association is not as widespread as previously suggested. Our findings are consistent with previous studies identifying a positive relationship between the two traits, but only if polyploidy promotes a transition to dioecy, and not the reverse.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140671192","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":"Foliar spectra accurately distinguish most temperate tree species and show strong phylogenetic signal","authors":"Florence Blanchard,&nbsp;Anne Bruneau,&nbsp;Etienne Laliberté","doi":"10.1002/ajb2.16314","DOIUrl":"10.1002/ajb2.16314","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Spectroscopy is a powerful remote sensing tool for monitoring plant biodiversity over broad geographic areas. Increasing evidence suggests that foliar spectral reflectance can be used to identify trees at the species level. However, most studies have focused on only a limited number of species at a time, and few studies have explored the underlying phylogenetic structure of leaf spectra. Accurate species identifications are important for reliable estimations of biodiversity from spectral data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using over 3500 leaf-level spectral measurements, we evaluated whether foliar reflectance spectra (400–2400 nm) can accurately differentiate most tree species from a regional species pool in eastern North America. We explored relationships between spectral, phylogenetic, and leaf functional trait variation as well as their influence on species classification using a hurdle regression model.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Spectral reflectance accurately differentiated tree species (<i>κ</i> = 0.736, ±0.005). Foliar spectra showed strong phylogenetic signal, and classification errors from foliar spectra, although present at higher taxonomic levels, were found predominantly between closely related species, often of the same genus. In addition, we find functional and phylogenetic distance broadly control the occurrence and frequency of spectral classification mistakes among species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results further support the link between leaf spectral diversity, taxonomic hierarchy, and phylogenetic and functional diversity, and highlight the potential of spectroscopy to remotely sense plant biodiversity and vegetation response to global change.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140626507","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":"Prevalent arbuscular mycorrhizae in roots and highly variable mycobiome in leaves of epiphytic subtropical fern Ophioderma pendulum","authors":"Qiao‐Yi Xie, Li‐Yaung Kuo, Chiung‐Chih Chang, Chien‐Jung Lin, Wen‐Hong Wang, Ko‐Hsuan Chen","doi":"10.1002/ajb2.16319","DOIUrl":"https://doi.org/10.1002/ajb2.16319","url":null,"abstract":"PremiseEndophytic and mycorrhizal fungi are crucial in facilitating plant nutrition acquisition and stress tolerance. In epiphytic habitats, plants face nutrition and water stress, but their roots are mostly nonmycorrhizal and especially lacking in arbuscular mycorrhizal associations. <jats:italic>Ophioderma pendulum</jats:italic> is an epiphytic fern with a partially mycoheterotrophic lifestyle, likely heavily reliant on symbiotic fungi. To characterize fungal associations in the sporophyte of <jats:italic>O. pendulum</jats:italic>, we focused on leaves and roots of <jats:italic>O. pendulum</jats:italic>, seeking to reveal the fungal communities in these organs.MethodsRoots and leaves from <jats:italic>O. pendulum</jats:italic> in a subtropical forest were examined microscopically to observe the morphology of fungal structures and determine the percentage of various fungal structures in host tissues. Fungal composition was profiled using metabarcoding techniques that targeted ITS2 of the nuclear ribosomal DNA.ResultsRoots were consistently colonized by arbuscular mycorrhizal fungi (Glomeromycota), especially <jats:italic>Acaulospora</jats:italic>. Unlike previous findings on epiphytic ferns, dark septate endophytes were rare in <jats:italic>O. pendulum</jats:italic> roots. Leaves were predominantly colonized by Ascomycota fungi, specifically the classes Dothideomycetes (46.88%), Eurotiomycetes (11.51%), Sordariomycetes (6.23%), and Leotiomycetes (6.14%). Across sampling sites, fungal community compositions were similar in the roots but differed significantly in the leaves.Conclusions<jats:italic>Ophioderma pendulum</jats:italic> maintains stable, single‐taxon‐dominant communities in the roots, primarily featuring arbuscular mycorrhizal fungi, whereas the leaves may harbor opportunistic fungal colonizers. Our study underlines the significance of mycorrhizal fungi in the adaptation of epiphytic ferns.","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140626632","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":"Leaf functional traits and ecological niche of Fagus grandifolia and Oreomunnea mexicana in natural forests and plantings as a proxy of climate change","authors":"Miriam Reyes-Ortiz,&nbsp;Andrés Lira-Noriega,&nbsp;Luis Osorio-Olvera,&nbsp;Isolda Luna-Vega,&nbsp;Guadalupe Williams-Linera","doi":"10.1002/ajb2.16322","DOIUrl":"10.1002/ajb2.16322","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Functional traits reflect species’ responses to environmental variation and the breadth of their ecological niches. <i>Fagus grandifolia</i> and <i>Oreomunnea mexicana</i> have restricted distribution in upper montane cloud forests (1700–2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200–1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait–niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher-elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34–0.58) than plantings (MD 0.50–0.70) for both species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species’ functional traits and phenotypic responses in optimal versus marginal environmental conditions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140630790","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}