Premise of research. Computer vision has the potential to become a transformative identification tool in biodiversity research and collections management, allowing high-throughput identification and removing the need for nonexpert end users to understand technical terminology. A major bottleneck for taxonomists is the generation of sufficient numbers of training images. Contemporary large-scale imaging projects of herbaria provide an increasing number of specimen photos, but whole-sheet images are not directly suitable for training image classification models targeted at individual taxonomically informative characters. Methodology. Here, we illustrate a time- and labor-efficient approach for generating training libraries for image classification from photos of herbarium sheets. It involves the annotation of specimen images with bounding boxes using open-source software and automated cropping of annotations with a custom script to produce the training library. We demonstrate the approach on the flower heads of a genus of Asteraceae comprising eight taxa, six species and two nontypus varieties. Pivotal results. After generating 816 training images from 33 specimen photos with a time investment of only ∼90 min, we trained an image classification model that achieved 98.2% precision and recall. Conclusions. The demonstrated approach allows taxonomists to use digitized herbarium specimens to produce training libraries for image classification models within hours. We expect that computer vision will increasingly become a part of taxonomic practice.
{"title":"Efficient Generation of Training Libraries for Image Classification Models from Photos of Herbarium Specimens","authors":"A. Schmidt‐Lebuhn, Nunzio J. Knerr","doi":"10.1086/724950","DOIUrl":"https://doi.org/10.1086/724950","url":null,"abstract":"Premise of research. Computer vision has the potential to become a transformative identification tool in biodiversity research and collections management, allowing high-throughput identification and removing the need for nonexpert end users to understand technical terminology. A major bottleneck for taxonomists is the generation of sufficient numbers of training images. Contemporary large-scale imaging projects of herbaria provide an increasing number of specimen photos, but whole-sheet images are not directly suitable for training image classification models targeted at individual taxonomically informative characters. Methodology. Here, we illustrate a time- and labor-efficient approach for generating training libraries for image classification from photos of herbarium sheets. It involves the annotation of specimen images with bounding boxes using open-source software and automated cropping of annotations with a custom script to produce the training library. We demonstrate the approach on the flower heads of a genus of Asteraceae comprising eight taxa, six species and two nontypus varieties. Pivotal results. After generating 816 training images from 33 specimen photos with a time investment of only ∼90 min, we trained an image classification model that achieved 98.2% precision and recall. Conclusions. The demonstrated approach allows taxonomists to use digitized herbarium specimens to produce training libraries for image classification models within hours. We expect that computer vision will increasingly become a part of taxonomic practice.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"98 1","pages":"387 - 391"},"PeriodicalIF":2.3,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78374289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rebecca B. Dikow, Jenna T. B. Ekwealor, William Mattingly, Michael Trizna, Elizabeth Harmon, Torsten Dikow, Carlos F. Arias, Richard G. J. Hodel, Jennifer Spillane, Mirian T. N. Tsuchiya, Luis Villanueva, Alexander E. White, Madeline G. Bursell, Tia Curry, C. inema, Kayla Geronimo-Anctil
Premise of research. Natural history collections are essential resources for taxonomy, systematics, and ecological and climate change research. Mass digitization of these collections provides the opportunity to study broad biological patterns among specimens and their associated metadata at a scale that was previously impossible. The specimen metadata can also be used to study the contributions of the people that collected and identified these specimens. A proper accounting of these contributions impacts our understanding of the history of these collections and who played a role in their growth. Methodology. Here, we provide an assessment of the scientific contributions of past women in science at the Smithsonian Institution, focusing on their specimen collections and identifications. We evaluate natural history specimen collections records available from the Global Biodiversity Information Facility and Smithsonian annual reports, volumes dating to the founding of the Smithsonian in 1846. Pivotal results. We identify 40 women with specimen collections or identifications, with a total of more than 120,000 total specimens attributed to them. In cases where specimens are not yet digitized, we are able to learn more about the women’s contributions using annual reports, which provide a richer picture of their work at the Smithsonian. This work relies on collaboration as well as deep institutional knowledge. We also release a semantic search application, which allows users to search the Smithsonian annual reports. Conclusions. Collections records are a rich resource, but there are significant barriers to accurate specimen attribution, which disproportionately affect women collectors and determiners. We propose ways that we might document these problems at scale and remedy cases of misattribution in digital repositories of record.
{"title":"Let the Records Show: Attribution of Scientific Credit in Natural History Collections","authors":"Rebecca B. Dikow, Jenna T. B. Ekwealor, William Mattingly, Michael Trizna, Elizabeth Harmon, Torsten Dikow, Carlos F. Arias, Richard G. J. Hodel, Jennifer Spillane, Mirian T. N. Tsuchiya, Luis Villanueva, Alexander E. White, Madeline G. Bursell, Tia Curry, C. inema, Kayla Geronimo-Anctil","doi":"10.1086/724949","DOIUrl":"https://doi.org/10.1086/724949","url":null,"abstract":"Premise of research. Natural history collections are essential resources for taxonomy, systematics, and ecological and climate change research. Mass digitization of these collections provides the opportunity to study broad biological patterns among specimens and their associated metadata at a scale that was previously impossible. The specimen metadata can also be used to study the contributions of the people that collected and identified these specimens. A proper accounting of these contributions impacts our understanding of the history of these collections and who played a role in their growth. Methodology. Here, we provide an assessment of the scientific contributions of past women in science at the Smithsonian Institution, focusing on their specimen collections and identifications. We evaluate natural history specimen collections records available from the Global Biodiversity Information Facility and Smithsonian annual reports, volumes dating to the founding of the Smithsonian in 1846. Pivotal results. We identify 40 women with specimen collections or identifications, with a total of more than 120,000 total specimens attributed to them. In cases where specimens are not yet digitized, we are able to learn more about the women’s contributions using annual reports, which provide a richer picture of their work at the Smithsonian. This work relies on collaboration as well as deep institutional knowledge. We also release a semantic search application, which allows users to search the Smithsonian annual reports. Conclusions. Collections records are a rich resource, but there are significant barriers to accurate specimen attribution, which disproportionately affect women collectors and determiners. We propose ways that we might document these problems at scale and remedy cases of misattribution in digital repositories of record.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"1 1","pages":"392 - 404"},"PeriodicalIF":2.3,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72643753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This special issue honors Dr. Vicki Ann Funk (November 26, 1947–October 22, 2019), who passed away after a battle with an aggressive cancer. She was a botanist at the Smithsonian Institution during her career from 1981 to 2019 after a postdoctoral year at the New York Botanical Garden. Vicki was an inspirational evolutionary biologist and a champion for collections-based systematics and biogeography. She had broad influence on the way we perform our collections-based systematics today, especially with the development of phylogenetic systematics in botany in the early 1980s and throughout her career. Vicki was one of the most active, enthusiastic, and passionate professional botanists of our time. She combined these qualities with a quick mind and glowing wit, always with new ideas or opinions that she was eager to share with anyone who would listen and be willing to enter an engaging dialogue. During her distinguished career, Vicki achieved preeminence in the fields of phylogenetic methods, systematics, biogeography, and biodiversity conservation. She devoted a significant part of her career to mentoring the next generation of botanists and working with groups to tackle larger areas of research, especially Compositae systematics, phylogenetics, and biogeography.
这期特刊纪念Vicki Ann Funk博士(1947年11月26日至2019年10月22日)，他在与侵袭性癌症作斗争后去世。1981年至2019年，她在纽约植物园做了一年博士后后，在史密森学会(Smithsonian Institution)担任植物学家。维姬是一位鼓舞人心的进化生物学家，也是以收集为基础的系统学和生物地理学的倡导者。她对我们今天进行以收集为基础的系统分类学的方式产生了广泛的影响，特别是在20世纪80年代初植物学系统发育系统分类学的发展以及她的整个职业生涯中。薇姬是我们这个时代最活跃、最热情、最具激情的专业植物学家之一。她将这些品质与敏捷的思维和机智相结合，总是有新的想法或观点，她渴望与任何愿意倾听并愿意进行迷人对话的人分享。在她杰出的职业生涯中，Vicki在系统发育方法、系统分类学、生物地理学和生物多样性保护领域取得了卓越的成就。在她的职业生涯中，她投入了相当大的一部分时间来指导下一代植物学家，并与团队合作解决更大领域的研究，特别是复合植物系统学、系统发育学和生物地理学。
{"title":"Collections-Based Science in the Twenty-First Century: A Tribute to the Botanical Giant Vicki Funk","authors":"W. L. Wagner, Jun Wen","doi":"10.1086/724308","DOIUrl":"https://doi.org/10.1086/724308","url":null,"abstract":"This special issue honors Dr. Vicki Ann Funk (November 26, 1947–October 22, 2019), who passed away after a battle with an aggressive cancer. She was a botanist at the Smithsonian Institution during her career from 1981 to 2019 after a postdoctoral year at the New York Botanical Garden. Vicki was an inspirational evolutionary biologist and a champion for collections-based systematics and biogeography. She had broad influence on the way we perform our collections-based systematics today, especially with the development of phylogenetic systematics in botany in the early 1980s and throughout her career. Vicki was one of the most active, enthusiastic, and passionate professional botanists of our time. She combined these qualities with a quick mind and glowing wit, always with new ideas or opinions that she was eager to share with anyone who would listen and be willing to enter an engaging dialogue. During her distinguished career, Vicki achieved preeminence in the fields of phylogenetic methods, systematics, biogeography, and biodiversity conservation. She devoted a significant part of her career to mentoring the next generation of botanists and working with groups to tackle larger areas of research, especially Compositae systematics, phylogenetics, and biogeography.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"30 1","pages":"405 - 411"},"PeriodicalIF":2.3,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83915625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Premise of research. The vast majority of eukaryotes reproduce by sexual reproduction, which is accompanied by meiotic recombination. Asexual reproduction, including the loss of meiosis, has been well characterized in several animal lineages but is vastly understudied in plants and particularly in the gametophyte life stage. Here, we explore the genomic consequences of strict clonal reproduction in the gametophyte-only fern Vittaria appalachiana. Methodology. Using publicly available transcriptome assemblies, we assessed how asexual reproduction can alter genomic features by comparing the transcriptomes of the asexually reproducing V. appalachiana (Pteridaceae) with sexually reproducing species in the same family, including congener Vittaria lineata. We explored several hypotheses relating asexual reproduction to the efficacy of purifying selection, transposable element load, GC-biased gene conversion, and the role of whole-genome duplications (WGDs). Pivotal results. We found putative support for predicted genomic consequences of asexual reproduction, including decreased efficacy of purifying selection (particularly in genes related to the cell cycle), altered transposable element load, and decreased GC content in V. appalachiana. We identified two putative WGDs, shared by Pteridaceae and the most recent common ancestor of the Vittaria genus, which may have contributed to V. appalachiana’s persistence over evolutionary time without sexual reproduction. Conclusions. Vittaria appalachiana is a gametophyte-only fern that is well suited to address fundamental questions regarding the long-term genomic effects of asexual reproduction in ferns, where this phenomenon has had little scientific attention in plants. This initial exploration into the genomic consequences of asexual reproduction is one of the first in ferns and highlights several avenues for future research.
{"title":"Life without a Sporophyte: The Origin and Genomic Consequences of Asexual Reproduction in a Gametophyte-Only Fern","authors":"Jessie A. Pelosi, W. Barbazuk, Emily B. Sessa","doi":"10.1086/724824","DOIUrl":"https://doi.org/10.1086/724824","url":null,"abstract":"Premise of research. The vast majority of eukaryotes reproduce by sexual reproduction, which is accompanied by meiotic recombination. Asexual reproduction, including the loss of meiosis, has been well characterized in several animal lineages but is vastly understudied in plants and particularly in the gametophyte life stage. Here, we explore the genomic consequences of strict clonal reproduction in the gametophyte-only fern Vittaria appalachiana. Methodology. Using publicly available transcriptome assemblies, we assessed how asexual reproduction can alter genomic features by comparing the transcriptomes of the asexually reproducing V. appalachiana (Pteridaceae) with sexually reproducing species in the same family, including congener Vittaria lineata. We explored several hypotheses relating asexual reproduction to the efficacy of purifying selection, transposable element load, GC-biased gene conversion, and the role of whole-genome duplications (WGDs). Pivotal results. We found putative support for predicted genomic consequences of asexual reproduction, including decreased efficacy of purifying selection (particularly in genes related to the cell cycle), altered transposable element load, and decreased GC content in V. appalachiana. We identified two putative WGDs, shared by Pteridaceae and the most recent common ancestor of the Vittaria genus, which may have contributed to V. appalachiana’s persistence over evolutionary time without sexual reproduction. Conclusions. Vittaria appalachiana is a gametophyte-only fern that is well suited to address fundamental questions regarding the long-term genomic effects of asexual reproduction in ferns, where this phenomenon has had little scientific attention in plants. This initial exploration into the genomic consequences of asexual reproduction is one of the first in ferns and highlights several avenues for future research.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"43 1","pages":"454 - 469"},"PeriodicalIF":2.3,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84861152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Premise of research. As the second leading cause of biodiversity loss worldwide, invasive species have been introduced accidentally or intentionally into many locations. To prevent their continued spread, identifying common pathways of introduction is critical, as Sarah Reichard emphasized in her classic 1994 study in which she analyzed 235 woody species considered invasive in the United States at that time and reported that the majority had current or historical uses in horticulture. Methodology. We now update her classic study with a literature review and expand it to herbaceous species by examining the origin of species identified as invasive today but within the Midwestern United States. Pivotal results. Of the 295 invasive species in this region, most introductions were through the ornamental trade, comprising 87.1% of trees and shrubs, 81.0% of vines, and 29.7% of terrestrial and aquatic herbs. We found that 85.5% of 83 invasive tree, shrub, and vine taxa in the Midwestern United States were associated with horticulture, compared with Reichard’s national estimate of 82% of 235 species nationwide. Conclusions. In the 29 years since Reichard’s review, the ornamental pathway continues today to be an avenue for the introduction of some plant species that later become invasive in the Midwestern United States, and, as such, the horticulture field could be effective in helping to reduce future plant invasions.
{"title":"The Role of Horticulture in Plant Invasions in the Midwestern United States","authors":"T. Culley, Tziporah Feldman","doi":"10.1086/724662","DOIUrl":"https://doi.org/10.1086/724662","url":null,"abstract":"Premise of research. As the second leading cause of biodiversity loss worldwide, invasive species have been introduced accidentally or intentionally into many locations. To prevent their continued spread, identifying common pathways of introduction is critical, as Sarah Reichard emphasized in her classic 1994 study in which she analyzed 235 woody species considered invasive in the United States at that time and reported that the majority had current or historical uses in horticulture. Methodology. We now update her classic study with a literature review and expand it to herbaceous species by examining the origin of species identified as invasive today but within the Midwestern United States. Pivotal results. Of the 295 invasive species in this region, most introductions were through the ornamental trade, comprising 87.1% of trees and shrubs, 81.0% of vines, and 29.7% of terrestrial and aquatic herbs. We found that 85.5% of 83 invasive tree, shrub, and vine taxa in the Midwestern United States were associated with horticulture, compared with Reichard’s national estimate of 82% of 235 species nationwide. Conclusions. In the 29 years since Reichard’s review, the ornamental pathway continues today to be an avenue for the introduction of some plant species that later become invasive in the Midwestern United States, and, as such, the horticulture field could be effective in helping to reduce future plant invasions.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"36 1","pages":"260 - 270"},"PeriodicalIF":2.3,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76352661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Hidalgo, Ismael Sánchez-jiménez, L. Palazzesi, B. Loeuille, T. Garnatje
Premise of research. The genus Echinops is unique among the Cardueae tribe of Asteraceae for presenting two distinctive features, both related to reproductive structures: a syncephalium (=secondary capitulum) and an impressively large pollen grain with a triangular section and probably the thickest of all plant cell walls. While the syncephalium constitutes a synapomorphy for the genus, recent evidence suggests that some Echinops species have pollen similar to that of other Cardueae. This study therefore seeks to contribute insights into the spatiotemporal frame of pollen evolution within the genus. Methodology. Micromorphological characterization was provided for 35 specimens from 28 Echinops species using light and scanning electron microscopy. Pollen counts were carried out for two Echinops species and Cardopatium corymbosum. Pollen data are discussed in the context of a dated Echinops phylogeny. For comparison purposes, new and published pollen data of 622 Cardueae species and 303 taxa of Vernonieae, another tribe where syncephaly has evolved, were collated. Pivotal results. The “Perennial” Echinops pollen type of huge size and triangular section likely derived from the “Annual” Echinops pollen type, more similar in shape, size, and exine structure to that of other Cardueae. Pollen type transition took place in the genus long after syncephaly evolved. Pollen size increase did not occur at the expense of pollen quantity and could respond to warmer environmental conditions and increased male competition. Conclusions. This study of Echinops pollen evidenced the evolutionary exploration of novel phenotypic space in the genus, most certainly in response to the climatic context in which the species have diversified.
{"title":"Pollen Evolution in the Genus Echinops (Cardueae, Asteraceae): Deciphering the Origin of Giant Pollen Grains","authors":"O. Hidalgo, Ismael Sánchez-jiménez, L. Palazzesi, B. Loeuille, T. Garnatje","doi":"10.1086/724497","DOIUrl":"https://doi.org/10.1086/724497","url":null,"abstract":"Premise of research. The genus Echinops is unique among the Cardueae tribe of Asteraceae for presenting two distinctive features, both related to reproductive structures: a syncephalium (=secondary capitulum) and an impressively large pollen grain with a triangular section and probably the thickest of all plant cell walls. While the syncephalium constitutes a synapomorphy for the genus, recent evidence suggests that some Echinops species have pollen similar to that of other Cardueae. This study therefore seeks to contribute insights into the spatiotemporal frame of pollen evolution within the genus. Methodology. Micromorphological characterization was provided for 35 specimens from 28 Echinops species using light and scanning electron microscopy. Pollen counts were carried out for two Echinops species and Cardopatium corymbosum. Pollen data are discussed in the context of a dated Echinops phylogeny. For comparison purposes, new and published pollen data of 622 Cardueae species and 303 taxa of Vernonieae, another tribe where syncephaly has evolved, were collated. Pivotal results. The “Perennial” Echinops pollen type of huge size and triangular section likely derived from the “Annual” Echinops pollen type, more similar in shape, size, and exine structure to that of other Cardueae. Pollen type transition took place in the genus long after syncephaly evolved. Pollen size increase did not occur at the expense of pollen quantity and could respond to warmer environmental conditions and increased male competition. Conclusions. This study of Echinops pollen evidenced the evolutionary exploration of novel phenotypic space in the genus, most certainly in response to the climatic context in which the species have diversified.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"119 1","pages":"366 - 377"},"PeriodicalIF":2.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80419916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Premise of research. Many plant species engage in mutualistic symbioses with soil biota such as arbuscular mycorrhizal (AM) fungi and rhizobium bacteria. Agricultural practices such as chemical fertilizer application and tilling can decrease the mutualistic functions of soil biota, but whether restoration of agricultural lands causes soil biota to increase mutualistic functions is not frequently studied. Methodology. To evaluate whether ecological restoration of agricultural lands increases mutualistic benefits that soil biota provide to plants, we grew a mycorrhizal- and rhizobium-responsive host plant (Trifolium pratense) in a common background soil that had been inoculated with soil biota from grasslands that had been restored in the past 9–12 yr and adjacent cultivated fields. Because both AM fungi and rhizobium are nutritional symbionts, we grew plants in each soil biota treatment under both low- and high-fertilizer amendments to assess whether mutualistic services would be reduced when nutrient availability was high. Pivotal results. Inoculation with soil biota from restored grasslands increased aboveground plant biomass by ~19% compared with cultivated fields, and this positive effect was observed at both low and high fertilizer levels. In the low-fertilizer treatment, percentage colonization of roots by AM fungi was 1.8 times higher in treatments receiving restored grassland versus cultivated field inoculum, but there was no difference in AM fungal colonization under high-fertilizer treatments. Rhizobium nodulation of roots did not differ between restored grassland and cultivated field inoculum sources in either fertilizer treatment. Conclusions. These results show that the mutualistic benefits of soil biota can increase following the restoration of previously cultivated fields to grasslands. The positive effect of soil biota on plant biomass was most likely caused by AM fungi rather than rhizobium bacteria. Increases in mutualistic benefits provided by soil biota can occur within a decade following grassland restoration of formerly cultivated agricultural fields.
{"title":"Grassland Restoration Increases Mutualistic Benefits That Soil Biota Provide to Plants","authors":"Hamrazsadat Soozandehfar, K. MacColl, H. Maherali","doi":"10.1086/724224","DOIUrl":"https://doi.org/10.1086/724224","url":null,"abstract":"Premise of research. Many plant species engage in mutualistic symbioses with soil biota such as arbuscular mycorrhizal (AM) fungi and rhizobium bacteria. Agricultural practices such as chemical fertilizer application and tilling can decrease the mutualistic functions of soil biota, but whether restoration of agricultural lands causes soil biota to increase mutualistic functions is not frequently studied. Methodology. To evaluate whether ecological restoration of agricultural lands increases mutualistic benefits that soil biota provide to plants, we grew a mycorrhizal- and rhizobium-responsive host plant (Trifolium pratense) in a common background soil that had been inoculated with soil biota from grasslands that had been restored in the past 9–12 yr and adjacent cultivated fields. Because both AM fungi and rhizobium are nutritional symbionts, we grew plants in each soil biota treatment under both low- and high-fertilizer amendments to assess whether mutualistic services would be reduced when nutrient availability was high. Pivotal results. Inoculation with soil biota from restored grasslands increased aboveground plant biomass by ~19% compared with cultivated fields, and this positive effect was observed at both low and high fertilizer levels. In the low-fertilizer treatment, percentage colonization of roots by AM fungi was 1.8 times higher in treatments receiving restored grassland versus cultivated field inoculum, but there was no difference in AM fungal colonization under high-fertilizer treatments. Rhizobium nodulation of roots did not differ between restored grassland and cultivated field inoculum sources in either fertilizer treatment. Conclusions. These results show that the mutualistic benefits of soil biota can increase following the restoration of previously cultivated fields to grasslands. The positive effect of soil biota on plant biomass was most likely caused by AM fungi rather than rhizobium bacteria. Increases in mutualistic benefits provided by soil biota can occur within a decade following grassland restoration of formerly cultivated agricultural fields.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"29 1","pages":"252 - 259"},"PeriodicalIF":2.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75897814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Premise of research. Fossil infructescences of the late Paleocene Cyclocarya brownii (Juglandaceae) and winged fruits with newly recognized anatomical structure are described from Almont and Beicegel Creek, North Dakota. These fossils demonstrate that C. brownii has many similarities to extant Cyclocarya paliurus but differs in several morphological and anatomical features. Comparisons of the fossil record of Cyclocarya document the transition of characters in the evolution of the oldest extant genus of Juglandaceae. Methodology. Fossils were digitally imaged with reflected light microscopy (LM). Some specimens were embedded in Ward’s Bio-Plastic synthetic resin, sectioned into wafers, mounted on microscope slides, and imaged with reflected LM. Permineralized specimens from the Beicegel Creek site were prepared with the cellulose acetate peel technique, mounted on microscope slides, and imaged with transmitted LM. Extant fruits of C. paliurus were photographed from freshly collected material. Pivotal results. Infructescences of C. brownii differ from those of modern C. paliurus in several ways. The fossils are racemes with crowded fruits borne on elongate pedicels. In contrast, extant C. paliurus has spikes bearing fewer fruits per infructescence (10 vs. 23). Fruit wall anatomy is similar to that of extant and other known fossil species of Cyclocarya but is more complex and has a distinctive idioblast layer not present in extant Cyclocarya. Fossil pollen is triporate in contrast to the tetraporate pollen in extant Cyclocarya. As in extant Cyclocarya, pollen is borne both in staminate catkins and occasionally in stamens attached to fruits. We document a fossil fruit with stamens bearing pollen. This feature, sporadic in extant Cyclocarya, was also present in the Paleogene. Conclusions. Late Paleocene C. brownii differs in comparison with extant C. paliurus and related fossil forms in infructescence architecture, fruit size and symmetry, fruit wall anatomy, and pollen aperture number. Trends in character evolution from the Paleogene to the present day include (1) changes from helically arranged, densely distributed pedicellate fruits to sessile fruits borne singly along a slender axis, (2) transition from pyramidal to round nutlets with (3) equatorial versus basal wing attachment, (4) a change in pollen aperture number from three to four, and (5) simplification of the fruit wall in extant Cyclocarya.
{"title":"New Features of Cyclocarya brownii Manchester & Dilcher from the Late Paleocene of North Dakota, USA","authors":"K. Pigg, M. Devore, Witt Taylor","doi":"10.1086/724496","DOIUrl":"https://doi.org/10.1086/724496","url":null,"abstract":"Premise of research. Fossil infructescences of the late Paleocene Cyclocarya brownii (Juglandaceae) and winged fruits with newly recognized anatomical structure are described from Almont and Beicegel Creek, North Dakota. These fossils demonstrate that C. brownii has many similarities to extant Cyclocarya paliurus but differs in several morphological and anatomical features. Comparisons of the fossil record of Cyclocarya document the transition of characters in the evolution of the oldest extant genus of Juglandaceae. Methodology. Fossils were digitally imaged with reflected light microscopy (LM). Some specimens were embedded in Ward’s Bio-Plastic synthetic resin, sectioned into wafers, mounted on microscope slides, and imaged with reflected LM. Permineralized specimens from the Beicegel Creek site were prepared with the cellulose acetate peel technique, mounted on microscope slides, and imaged with transmitted LM. Extant fruits of C. paliurus were photographed from freshly collected material. Pivotal results. Infructescences of C. brownii differ from those of modern C. paliurus in several ways. The fossils are racemes with crowded fruits borne on elongate pedicels. In contrast, extant C. paliurus has spikes bearing fewer fruits per infructescence (10 vs. 23). Fruit wall anatomy is similar to that of extant and other known fossil species of Cyclocarya but is more complex and has a distinctive idioblast layer not present in extant Cyclocarya. Fossil pollen is triporate in contrast to the tetraporate pollen in extant Cyclocarya. As in extant Cyclocarya, pollen is borne both in staminate catkins and occasionally in stamens attached to fruits. We document a fossil fruit with stamens bearing pollen. This feature, sporadic in extant Cyclocarya, was also present in the Paleogene. Conclusions. Late Paleocene C. brownii differs in comparison with extant C. paliurus and related fossil forms in infructescence architecture, fruit size and symmetry, fruit wall anatomy, and pollen aperture number. Trends in character evolution from the Paleogene to the present day include (1) changes from helically arranged, densely distributed pedicellate fruits to sessile fruits borne singly along a slender axis, (2) transition from pyramidal to round nutlets with (3) equatorial versus basal wing attachment, (4) a change in pollen aperture number from three to four, and (5) simplification of the fruit wall in extant Cyclocarya.","PeriodicalId":14306,"journal":{"name":"INTERNATIONAL JOURNAL OF PLANT SCIENCES","volume":"84 1","pages":"282 - 303"},"PeriodicalIF":2.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80425922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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