Maclura pomifera (Raf.) Schneid.

https://thekeep.eiu.edu/herbarium_specimens_byname/19975/thumbnail.jp

Maclura pomifera (Raf.) Schneid.

https://thekeep.eiu.edu/herbarium_specimens_byname/19975/thumbnail.jp

Fluidity and Inconstancy: Australian Bush Tomatoes as an Exemplar of Non-Normative Sex Expression

Solanum, a genus of ~1500 global species, is one of the more interesting plant groups in which to study reproductive biology and ecology. Overwhelmingly, species in this group express full cosexuality, where individual plants have flowers containing both fully-functioning “male” (staminate) and “female” (carpellate) organs. However, there have been multiple and widespread evolutionary transitions within the genus to non-normative variations on this ancestral condition. Australian bush tomatoes (ca. 40 species) are especially diverse in this regard, with uncommon variation and combinations of unisexuality and cosexuality -- including, most notably, two sexual systems known as dioecy (unisexual male or female flowers on separate plants) and andromonoecy (combinations of male and cosexual flowers on every plant). This commentary summarizes 40+ years of study and highlights some of the more intriguing observations/findings that make the bush tomatoes an ideal model system for examining plant sexual expression – including functionally “female” flowers (in which “male” organs are formed and pollen is produced, but that pollen serves only as a reward to pollinators and plays no other role in sexual reproduction), leaky “male” plants (in which “male” flowers sometimes express “female” function via functional pistils and thus become cosexual), the preponderance of vestigial opposite-sex organs in unisexual flowers, and species (such as the recently-described S. plastisexum) where variation in sexual expression is the norm rather than the exception

Investigation into the Genetic Provenance of Three Rare Plants with East-West Disjunction Patterns in Pennsylvania.

Rare plant conservation relies on an understanding of the natural history, biology and ecology, and real and potential threats to their populations to inform state regulations that serve to protect the species from extirpation. This work often involves extensive field surveys over several years to determine population sizes and whether those populations are seeing reductions in number of individuals necessary to maintain the genetic diversity within and between those populations. Species and populations with high genetic diversity are better equipped to withstand sudden changes to their habitats that derive from land use changes and changing climate. There are a variety of methods used to investigate population genetic diversity and next generation sequencing (NGS) methods allow for complete genomic coverage by analyzing single nucleotide polymorphisms (SNPs) and allowing for an estimation of population genetic parameters such as genetic variation (FST), the inbreeding coefficient (FIS), and heterozygosity (HO) (HE). Population genomic investigations of Baptisia australis, Chasmanthium latifolium, and Erigenia bulbosa, plant species at the edge of their ranges in Pennsylvania and disjunct distributions within the state were performed for this study. All three species exhibited lower than expected heterozygosity and, with the exception of Chasmanthium, high levels of inbreeding. This information was incorporated into conservation rank status assessments and climate change vulnerability indices using the NatureServe Conservation Status Rank Calculator and the Climate Change Vulnerability Index tools. As a result, state ranks for Chasmanthium and Erigenia require formally proposed changes to the Department of Conservation of Natural Resources. Likewise, management recommendations are given as guidance on the steps likely necessary to preserve and potentially increase the genetic diversity for all species. Through these investigations, a long-term partnership between the Pennsylvania Natural Heritage Program at Western Pennsylvania Conservancy and Bucknell University was developed through which a pipeline of undergraduate and graduate students were, and will be, trained in both field-based natural heritage methods and new, innovative ways address the conservation of rare plants in Pennsylvania and beyond

Cross-pollination: Building a Co-taught Course to Examine Art and Sex Through the Lens of Botany

Driven by overlapping interests in plants, art, and diversity in sex expression, Anna Kell (Department of Art and Art History) and Chris Martine (Department of Biology) developed a course that integrates the perspectives of a visual artist and a botanist. Art & Sex Through the Lens of Botany seeks to impart the importance of making connections across disciplines and the value of visual literacy across academic lines. The course introduces foundational concepts in each field and encourages students to integrate and explore these different systems of knowledge and their intersections. In addition to developing fluencies related to both general botany and studio art, the goal of the course is that students demonstrate a variety of new strengths including a) the ability to recognize, construct, and evaluate connections among different intellectual methods, ways of learning, and bodies of knowledge; b) the ability to identify the various parts of a flower and discuss their significance and role in sexual reproduction in plants; c) increased awareness of visual forms of communication, including artistic expression, data visualization, and observation; and d) a broader understanding of the role of sexuality in the science of biology and in the formation of cultural beliefs and biases

Lepidopteran Granivory Reduces Seed Counts in a Rare Species of Riparian Scour Prairies

In Pennsylvania Baptisia australis var. australis is found along only four waterways: the Allegheny River, Youghiogheny River, Clarion River, and Red Bank Creek. Because of its limited distribution and small number of extant populations, the species is considered state-threatened in Pennsylvania. In addition, the riparian prairie habitat that Pennsylvania Baptisia australis var. australis is restricted to is also in decline and considered vulnerable. Because of these conservation concerns, insights into the natural history of the taxon in the state is valuable and will inform conservation efforts. Field surveys and fruit collections along the Allegheny River and herbarium collections were used to investigate and document granivory in Pennsylvania Baptisia australis var. australis, a phenomenon recorded in other parts of the species\u27 range, but not previously reported on in Pennsylvania. Using a model of best fit, the number of seeds found in fruit was found to be significantly impacted by the presence of granivores. We also report that visual surveys of fruits in the field are found to be accurate assessments of the presence and potential impact of granivores. In turn, our results will inform the conservation and management of Baptisia australis var. australis populations in Pennsylvania and highlight the importance of field surveys in protecting threatened taxa

Natural History Collections: Teaching About Biodiversity Across Time, Space, and Digital Platforms

Natural history collections offer unique physical and virtual opportunities for formal and informal progressive learning. Collections are unique data in that they each represent a biological record at a single place and time that cannot be obtained by any other method. Collections-based experiences lead to an increased understanding of and substantive interaction with the living world. Global biological diversity and changes in that diversity are directly tracked through specimens in collections, regardless of whether changes are ancient or recent. We discuss how collections, specimens, and the data associated with them, can be critical components linking nature and scientific inquiry. Specimens are the basic tools for educating students and interested citizens through direct or virtual contact with the diversity of collections. Such interactions include instruction in a formal classroom setting, volunteering to gather and curate collections, and informal presentations at coffee shops. We emphasize how the recent surge in specimen-based digitization initiatives has resulted in unprecedented access to a wealth of biodiversity information and how this availability vastly expands the reach of natural history collections. The emergence of online databases enables scientists and the public to utilize the specimens and associated data contained in natural history collections to address global, regional, and local issues related to biodiversity in a way that was unachievable a decade ago

Integrated pest management in the academic small greenhouse setting: A case study using Solanum spp. (Solanaceae).

Premise Botanical faculty and staff at academic institutions are often tasked with establishing and/or caring for plant collections held in small greenhouse facilities. Once plants are in place, an especially acute challenge is managing plant pest/pathogen populations. Integrated pest management (IPM) approaches are an excellent option, but few examples exist in the literature of successful programs that have been developed in academic small greenhouse settings. Methods and Results Over several years, we developed an IPM program for two small research greenhouses on the campus of a primarily undergraduate institution where hundreds of plants have been grown for studies in the genus Solanum. We here present a synopsis of the cultural, mechanical, physical, and biological controls used as part of our successful IPM strategy—including details on the efficacy of multiple predatory insects—with the hope of providing a model for sustainable pest management in the higher education environment. Conclusions IPM can be an effective strategy for maintaining healthy plant populations in small research greenhouses, but it requires a consistent investment of time and funding. A well‐cared‐for plant collection might help support numerous positive outcomes, including advances in faculty scholarship and opportunities for student learning and/or training

Temperate Eurasian Origins of Hawaiian Chenopodium (Amaranthaceae) plus description of a new species endemic to Moloka‘i

Chenopodium taxa of Hawai‘i are tetraploids distinguished from other members of the circumglobally distributed genus by minute morphological characters. Because of these reasons, the geographic origin of Hawaiian Chenopodium has remained unclear. Across the Hawaiian Archipelago, Chenopodium taxa are morphologically variable and grow in highly disparate xeric habitats, especially in terms of precipitation, temperature, wind, salt spray, and solar irradiation. Habitats include dry subalpine shrublands, sandy beach strand of atolls in the Northwest Hawaiian Islands, dry forests, and precipitously tall sea cliffs of northwestern Moloka‘i. From the Moloka‘i sea cliffs, which are battered by high energy winds, salt spray, and strong seasonal precipitation, we describe C. oahuense subspecies ilioensis as segregated from the widespread Hawaiian C. oahuense s.l. Morphometric analyses distinguish C. oahuense ssp. ilioensis through its strongly prostrate to scandent habit, thick succulent leaves, smaller average leaf sizes, limited leaf margin lobing, and smaller seeds. Phylogenetic analyses using two DNA regions (the plastid gene rpl32-trnL and nuclear ITS1-5.85 rDNA-ITS2) of newly sequenced C. oahuense s.l. and C. oahuense ssp. ilioensis individuals plus outgroup taxa support monophyly of Hawaiian Chenopodium and reveal a geographic origin of temperate Eurasia. Two equivocal hypothetical scenarios are discussed regarding the likely sequence of events leading to the arrival of Chenopodium in Hawaiian Islands followed by possible in situ speciation of the Moloka‘i endemic C. oahuense ssp. ilioensis

A Foundational Population Genetics Investigation of the Sexual Systems of Solanum (Solanaceae) in the Australian Monsoon Tropics Suggests Dioecious Taxa May Benefit from Increased Genetic Admixture via Obligate Outcrossing

Solanum section Leptostemonum is an ideal lineage to test the theoretical framework regarding proposed evolutionary benefits of outcrossing sexual systems in comparison to cosexuality. Theoretically, non-cosexual taxa should support more genetic diversity within populations, experience less inbreeding, and have less genetic structure due to a restricted ability to self-fertilize. However, many confounding factors present challenges for a confident inference that inherent differences in sexual systems influence observed genetic patterns among populations. This study provides a foundational baseline of the population genetics of several species of different sexual systems with the aim of generating hypotheses of any factor—including sexual system—that influences genetic patterns. Importantly, results indicate that dioecious S. asymmetriphyllum maintains less genetic structure and greater admixture among populations than cosexual S. raphiotes at the same three locations where they co-occur. This suggests that when certain conditions are met, the evolution of dioecy may have proceeded as a means to avoid genetic consequences of self-compatibility and may support hypotheses of benefits gained through differential resource allocation partitioned across sexes. Arguably, the most significant finding of this study is that all taxa are strongly inbred, possibly reflective of a shared response to recent climate shifts, such as the increased frequency and intensity of the region’s fire regime