Science

The creation of the Isthmus of Panama approximately 3 Ma provided the opportunity for the southern and northern migrations of animals, fungi, and plants known as the Great American Biotic Interchange. Historical biogeography has largely focused on the fauna and flora of the region in relation to this event. There is no comprehensive study of how important geological events such as this shaped the diversity of organisms in soil communities where organisms like fungi and microbes engage in biotrophic and saprotrophic ecological interactions with the animal and plant communities.

Fungi are critical for society, both through direct impacts on human health and the economy and through their intimate involvement in most essential environmental processes. However, even though they are not immune to the stressors that threaten animals and plants, including habitat loss, over harvesting, and climate change, fungi are often not included in conservation discussions, planning, or action.

Schiedea is a genus of 34 species in the carnation family (Caryophyllaceae) that is found only in the Hawaiian Islands. This genus of plants is known for having an extraordinary diversity of reproductive systems and serves as an excellent model to study how these systems evolved, particularly in the context of island biology. However, many of these species are threatened or endangered, and two have already gone extinct. In this project, we are using DNA sequence data to understand how these plants evolved and to form the foundation of future conservation efforts.

Wetlands are very diverse and support several threatened and endangered species. Yet, they are among the most stressed ecosystems in the world. To support their conservation and prioritize interventions where they are most needed, it is critical to quantify wetland plant diversity and identify its drivers. This project uses different indicators derived from satellite imagery to estimate the plant diversity of wetland sites across the conterminous United States.

In partnership with The Nature Conservancy, we are working to harvest and map open-sourced community science data submitted through Budburst and iNaturalist applications in Cook and Lake Counties (Illinois), as well as existing collections data from local herbaria and animal collections. This project has two major goals: determining how (1) the ecological community context (e.g.

In the 1800s, grasslands of North America were vast. Since then, about 99 percent of the tallgrass prairie has been destroyed. The small, isolated patches of prairie that remain harbor many plant species; yet, rates of local plant extinctions are alarmingly high. This long-term project investigates why some populations go extinct and others persist in the face of changing environmental conditions. We focus on two evolutionary processes affecting a model prairie plant species, a purple coneflower, Echinacea angustifolia: adaptation and inbreeding depression.

Vanilla is an economically important crop used for flavoring and fragrances. The vanilla "bean" isn't a bean, it is the fruit of the vanilla orchid. This project is investigating if different cultivation practices influence the associated fungi and bacteria (benefical as well as pathogens) found in the roots of vanilla orchids using NextGen sequencing approaches. The study is being undertaken as part of an international team focused on factors influencing the production of vanilla (Mueller, Johnson, and colleagues).

Seasonally dry tropical forests (SDTF) account for nearly half of the world’ s tropical and subtropical forests but remain one of the most endangered habitats. High rates of forest clearing for pasture, frequent fires, and pressure from population growth have all contributed to severe fragmentation and degradation of SDTF. Most conservation efforts to date have been directed toward specific plant taxa or areas that contain high levels of plant endemism.

Cantharellacae includes choice edible fungi such as chanterelles and trumpet fungi. They also are important beneficial symbionts of forest trees. Many species in the group are listed as threatened and endangered in countries that list fungi. Activities in 2014 focused on completing work on documenting the diversity of the group in the Chicago region. DNA analyses confirmed the occurrence of an undescribed species in the yellow chanterelle group.

Laccaria has been used as a model group to study fungi that form ectomycorrhizas (beneficial symbionts of forest trees). Activities in 2014 saw the completion of a multi-year project that combined information from long-term fieldwork with DNA analyses to document the group's diversity, evolutionary relationships, and biogeographic patterns. This resulted in the most comprehensive study of any genus of ectomycorrhizal fungi. A final draft of the first in a series of manuscripts resulting from this work was completed.

A lack of information on the population biology of fungi has greatly hindered efforts to understand their biology and to include them in conservation discussions and action plans. Studies have been severely limited by difficulties in obtaining genetic markers to differentiate among individuals and populations needed to examine issues such as fragmentation, the effect of pollution, and potential over-harvesting for food.

Approximately 470 million years ago, the first plants to inhabit land arose from green algae. Subsequently, these plants diversified to form the foundation of all terrestrial ecosystems. As part of a collaboration with the 1KP project (a multidisciplinary consortium of plant biologists and bioinformaticians led by researchers at the University of Alberta and Beijing Genomics Institute in Shenzhen, Hong Kong), we developed methods to process large amounts of DNA sequence data to better understand the origin and evolution of early land plants.

Diatoms account for roughly 20 percent of global primary production, while making up less than 0.2 percent of primary producer biomass. Additionally, they are the key drivers of biogeochemical silica cycling and have acquired a diverse set of metabolic pathways including a complete urea cycle (previously only known from animals), iron-concentrating mechanisms, and polyamine biosynthesis. Surprisingly, these diverse functional traits were all enabled by the acquisition of genes transferred horizontally from bacteria.

With a National Science Foundation grant, the Chicago Botanic Garden is working with international collaborators in Southeast Asia to study the distribution and evolution of an economically important group of plants. With approximately 70 species, Artocarpus is the third largest genus in the plant family that contains figs and mulberries (Moraceae). Artocarpus contains numerous economically important species (grown for timber and fruit) native to Southeast Asia. Two species, jackfruit and breadfruit, are cultivated throughout the tropics.

Mongolia has an abundance of fossil deposits that date to the early Cretaceous (approximately 100 to 130 million years ago), when flowering plants first appeared in the fossil record and then rapidly diversified. The fossil record is the best source of evidence to document the origin and early evolution of a group of plants such as the angiosperms. Although much paleontology work has been done in Mongolia searching for dinosaurs, very little field work and research on fossil plants has been undertaken there.

The legume family, which includes important crop plants (e.g., beans, peas, and soybeans) and many other economically important species, is the third largest plant family, with approximately 800 genera and over 19,000 species found in all parts of the world. In addition to being a source for economically important plants, the family is also important because legumes dominate many tropical ecosystems.

Pleurocarpous mosses are traditionally defined as having short, lateral reproductive branches. Pleurocarps (Hypnanae) compose the most speciose lineage of mosses, a result of an explosive radiation during the Jurassic period, at a time when flowering plants began to dominate many terrestrial environments. Repeated multidirectional habitat transitions occurred as this group evolved, leading to the loss of morphological characters that may be used to describe groups.

The striking diversity of floral shapes, color, and scent has captivated poets and scientist alike. However, Darwin noted that the diversity of flowering plants was almost too great to believe, something he referred to it as the “abominable mystery.” The quest to answer why we have so many flowering plants is still ongoing and has made flowers a model group to answer important questions about speciation. One particularly challenging aspect of the mystery is how new forms arise and spread.

The Science Collections website launched in 2013, allowing public access to information on all research samples held at the Chicago Botanic Garden. Currently we have accessioned more than 4,950 genetic samples, which come from a broad variety of sources including living collections (Tankersley), Seed Bank (Vitt, Yates, and Sollenberger), DNA collections (Fant), and herbarium (Zerega and Masi). Plans are also underway to add important rare species and research samples that will increase the value of this collection (Fant and Rosenbaum).