Archives For Plant Science & Conservation

Conserving plants is one of the most significant challenges of our time—and a major focus at the Chicago Botanic Garden. From studying soil to banking seeds, from restoring habitats and protecting endangered plant species to developing new ones, Garden scientists are fighting plant extinction, pollution, and climate change through diverse and exciting research.

For this year’s Orchid Show, we’ve gathered stories about the most famous orchid of them all: the genus Vanilla. (Yes, vanilla is an orchid.) One unusual story comes from Ph.D. student Lynnaun Johnson, whose work in our doctoral program in Plant Biology and Conservation took him to Mexico, the native land of edible vanilla.

 

Last April, I ventured to Mexico as part of an international team investigating how cultivation practices influence the growth and health of the orchid Vanilla planifolia.

Vanilla planifolia produces the seedpods used to make vanilla, the spice used for flavoring desserts and beverages, and for providing wonderful aromas in candles, perfumes, and many other things. This collection trip would take me to vanilla’s native habitat of Mexico. All varieties of vanilla originated in Mexico, including those of Madagascar and Tahiti.

Vanilla cultivation

PHOTO: Vanilla planifolia bloom.

Tahitian vanilla is a hybrid of V. planifolia (shown) and V. odorata. Photo by H. Zell CC-BY-SA-3.0

While in Mexico, I visited three farms in the state of Veracruz and one in the state of Puebla. It was fascinating driving to these vanilla farms with my Mexican collaborators. It took us three days of traveling to complete our field collections. Each of the four farms had very different methods of growing V. planifolia. For instance, one of the farmers said he knew what his plants needed and thought growing his vanilla on concrete blocks was the best method. At another farm, the farmer brought decaying wood from a neighboring forest and used it as mulch for his vanilla plants that grew on living posts known as “tuteurs.” This was different from the other farmers who grew their vanilla on trees in the forest and wooden dead “tuteurs.”

Each of the plantations had different soil texture. At the last organic farm, the soil was compact and hard. At the farms that were in the forest, the soil appeared rich and softer. There is no way to quantify the terrestrial root growth, but I did note that the roots in the organic farms were longer and healthier, with some growing up to 4 or 5 feet when we dug the roots up from the soil.

PHOTO: A view of the Pantapec vanilla farm.

At the Pantapec farm in the state of Puebla, Mexico, vanilla is cultivated in a highly managed environment.

PHOTO: A view of the 1 de Mayo vanilla farm

By contrast, the vanilla grown at 1 de Mayo farm in the state of Veracruz, Mexico, is cultivated in a completely natural environment.

The benefits of fungi

PHOTO: Orchid tissue microscopy at 100x.

Research on rare and endangered orchids usually focuses on finding fungi to help in the germination of orchids. We know that orchids will only germinate in nature using fungi. In addition, fungi living inside of plant leaves can benefit the plants’ health by preventing pathogens from growing. Also, bacteria living within the plants and fungi can be beneficial in the same way as the endophytic fungi. (Photo: V. planifolia tissue microscopy at 100x)

My part of the research project is to collect root samples from V. planifolia from each of these different farms to study the fungi and bacteria inhabiting this orchid. Currently, not much is known about the microbes (fungi and bacteria) that reside in orchid roots. Some fungi and bacteria can cause diseases. For example, with the appearance of a fungal pathogen such as Fusarium oxysporum, Mexican farmers can lose 67 percent of their crops when the Fusarium causes the rotting of the Vanilla’s stem and roots. On the other hand, there are beneficial fungi that inhabit roots, known as mycorrhizal fungi. These beneficial symbiotic fungi acquire mineral nutrients for the Vanilla, and sometimes receive carbon from the orchid in exchange. Although 90 percent of plant species have mycorrhizal fungi, and while we have a good understanding of mycorrhizal fungi of some of these relationships, relatively little is known about the mycorrhizal fungi of orchids, including V. planifolia. The reason for this is that isolating and growing the fungi and bacteria associated with orchid roots can be difficult, and some have never been grown outside of their host.

At each farm, I wanted to sample five individual plants of V. planifolia. Additionally, because of the lifestyle of this orchid, I also wanted to sample the above-ground roots (epiphytic) and the below-ground (terrestrial) roots in the soil. Using either a scissors or a scalpel, I cut small root samples and placed them into Ziploc bags. The vanilla plants are very precious to the farmers, and so a few were initially uncomfortable with our cutting off pieces, but ultimately they were very accommodating.

Epiphytic or terrestrial?

PHOTO: The Vanilla orchid's epiphytic roots.

Typically, vanilla grows as a vine, with two types of roots: epiphytic roots (those that wrap around trees or other structures) and terrestrial (soil) roots. This is referred to as hemiepiphytic, because it starts in the ground and grows upward onto the tree’s bark. Many research papers suggest that epiphytic roots do not harbor many fungi, because these roots can photosynthesize, and do not need mutualistic fungus partners.

Back here at the Chicago Botanic Garden, I am in the process of evaluating the microbial community that lives in the root samples I collected. We are using a new technique called high-throughput sequencing that will enable me to evaluate the entire fungal and bacterial community within the orchid’s roots by using their DNA as a way to fingerprint the individual species of microbes. We are not certain how many species of fungi and bacteria we will find, but we predict that this method will give us a good picture of the fungal and bacterial community in these roots and if these communities differ among the different farming techniques. These data will be used to better understand how epiphytic orchids utilize mycorrhizal fungi and refine the best conditions to grow vanilla and prevent diseases in the plants.

This research trip was a delight, not only because of the samples that I collected, but also because I could learn more about how vanilla is grown and used. The farmers showed us how they cure and prepare the vanilla by fermenting it in the sun and before drying it thoroughly. I also tasted homemade “vanilla moonshine,” generously offered by the farmer’s wife. When visiting Papantla, I learned about the Aztec myth that explained how forbidden love created the sacred vanilla orchid. And of course, I was elated because I usually spend the majority of my research time in the lab. And here I was in the tropics, after spending the previous months facing the bitter Chicago 2014 winter.


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Between a Rock and a Future

Undercover Science

Julianne Beck —  January 10, 2015 — Leave a comment

A pretty little iris growing in the mountainous rocky outcrops of Jerusalem is the focus of a research collaboration stretching over 6,000 miles.

Scientists at the Chicago Botanic Garden and Jerusalem Botanical Gardens have combined their strengths to study the natural population structure, or remaining genetic diversity, of the rare Iris vartanii. What they have discovered may save the species, and others like it, into the future.

The finicky wildflower exists in just 66 locations in Israel’s Mediterranean ecosystem—a dangerously low number. New road construction, urban expansion, and even afforestation in the area have reduced the availability of its natural habitat, fueling the crisis. For a plant that is endemic to, or only lives in, one narrow region, that spells trouble.

PHOTO: Iris vartanii ©Dr. Ori Fragman-Sapir

Iris vartanii Photo ©Dr. Ori Fragman-Sapir

“Whenever you have a rare plant, you always have concern that as diversity starts to go down, the plant becomes more and more endangered,” explained Garden volunteer and molecular biologist Eileen Sirkin, Ph.D. “The idea of diversity is that maybe one plant is more drought tolerant, another is more flood tolerant, and another is more wind tolerant, for example, so no matter what the conditions, there will be some survivors. As you narrow that, you are more and more in danger of losing that species.”

Do the existing plants contain adequate genetic diversity? And to sustain the species, how many plants are enough? These are the central questions.

Gaining a Foothold

The scientific partnership between the two gardens was forged when Jerusalem Botanical Gardens’ Head Scientist Ori Fragman-Sapir, Ph.D., who has monitored the species and studied its demography in the field, visited the Chicago Botanic Garden and met with Chief Scientist Greg Mueller, Ph.D. The two quickly saw an opportunity to combine Dr. Fragman-Sapir’s research with the genetic capabilities of the Garden to answer those critical questions.

“Conservation genetics is one of the core strengths of our science program,” said Dr. Mueller.  “There are few other botanical institutions that have this expertise, especially internationally, so we are happy to collaborate on interesting and important plant conservation projects like this one.”

“Conservation genetics is one of the core strengths of our science program,” said Dr. Mueller. “There are few other botanical institutions that have this expertise, especially internationally, so we are happy to collaborate on interesting and important plant conservation projects like this one.”

It wasn’t long before Fragman-Sapir began shipping leaf samples to the Garden’s molecular ecologist, Jeremie Fant, Ph.D. Together with his dedicated volunteer Dr. Sirkin, Dr. Fant set to work extracting data from the samples and documenting DNA fingerprints for each plant. Once they had a large enough data set, they compared and contrasted the findings—looking for similarities and differences among the plants’ genetic compositions.

Gaining Altitude

To give scientists a point of comparison, Fragman-Sapir shared tissue samples from five populations (geographically separated clusters of plants) of a more commonly occurring related species, Iris histrio. By also documenting the DNA fingerprints of those plants, which grow in the surrounding area, but unlike Iris vartanii are not rare, Fant was able to determine how much diversity is needed to sustain the species.

PHOTO: Volunteer Dr. Eileen Sirkin

Dr. Eileen Sirkin volunteers in the laboratory.

Although the study subject is far away from the Garden, its challenges hit close to home. In 2013, Fant and Sirkin published findings from a similar study on a rare plant found at Illinois State Beach Park, Cirsium pitcheri. For that initiative, they examined the DNA of plants from a restored site at the beach and compared them to the DNA of naturally occurring plants across the range, measuring diversity.

“We’re always working with rare and endangered species, and we collaborate with different people around the world to answer those questions,” explained Sirkin.

The Summit

After completing a statistical analysis of Iris vartanii’s DNA fingerprints, Fant made several encouraging conclusions but also issued an alert for continued attention.

The rare species’ genetic diversity was similar to that of Iris histrio. “This does tell us that genetic diversity in Iris vartanii is not likely an issue,” said Fant, who was not surprised by the conclusion. “Genetic diversity of any population is determined by the origins of the species, the age of the population, and proximity to the site of origin,” he explained. “As both species likely arose locally [from Jerusalem northward to the Galilee and further on] and have been around for a very long time, they possess similar levels of genetic diversity.”

PHOTO: Dr. Jeremie Fant.

Conservation scientist Dr. Jeremie Fant

Especially encouraging was that each Iris vartanii population had significant differences in their genes, likely a result of their longtime separation. The findings highlight that it is all the more valuable to conserve each population for their potential to contribute unique genes to future plants, according to Fant.

Although many populations showed high diversity and low inbreeding, which is preferred, others showed the reverse, increasing their potential risk of extinction. The latter group, explained Fant, may benefit from extra special monitoring and care.

To conserve the existing populations, attention will need to be given to their surrounding natural areas, explained Sirkin. “If you find a species that people like and you study it and say we need to do all these things to save it, you are not just saving one plant, you are saving an ecosystem, including all the other plants, insects, other invertebrates, lizards, birds, and whatever else is involved in that ecosystem,” she said.

The findings and recommendations give land managers a clear direction for their conservation efforts, all because of one eye-catching plant that told the story of many.


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Mushroom Discovery

Julie McCaffrey —  December 29, 2014 — Leave a comment

All the possibilities for the Obama Library plus our Windy City Harvest Youth Farm are featured on National Geographic’s website! Read about it in Greg Mueller’s article, The Next New Species Could be in Your Backyard: Why Exploration and Discovery Matter—Everywhere on National Geographic. Mueller, chief scientist and Negaunee Foundation vice president of science at the Garden, describes the excitement of discovering new species in our own neighborhoods and parks.

Collection: Patrick R. Leacock 5450 2003 Aug 9 USA, Illinois, Cook County Illinois Mycological Association foray Herbarium: F, C0210207F

Photograph by Patrick R. Leacock

Read more by Garden scientists at voices.nationalgeographic.com
Copyright © 2014 National Geographic

The Long Road Home

Undercover Science

Julianne Beck —  December 11, 2014 — 1 Comment

Golden paintbrush (Castilleja levisecta) is gaining ground in its native Oregon for the first time in more than 80 years. Recent reintroductions have seen the charismatic species flourish on its historic prairie landscape. To keep the momentum going, scientists are pulling out all the stops to ensure that the new populations are robust enough to endure.

“Genetic variability will be key to the reintroduction success of golden paintbrush,” explained Adrienne Basey, graduate student in the plant biology and conservation program of the Chicago Botanic Garden and Northwestern University.

PHOTO: Golden paintbrush (Castilleja levisecta).

Golden paintbrush (Castilleja levisecta) growing in propagation beds in Oregon. Photo by Tom Kaye

Basey, who previously managed a native plant nursery, is now studying the genetic diversity of golden paintbrush plants before, during, and after they are grown in a nursery prior to reintroduction to the wild.

“My work is looking at the DNA, or genetics, of the wild, nursery, and reintroduction populations to see if there is any change through that process,” she said. If there is a change, she will develop recommendations for adjusting the selection and growing process to better preserve diversity. “My goal is to give both researchers and practitioners more information to work with,” she noted.

Building for the Future

The research is unique in the relatively young field of restoration science, according to Basey’s co-advisor and molecular ecologist at the Garden, Jeremie Fant, Ph.D. “Adrienne’s study is awesome because of the fact that it has data and the samples to back it up; it is early on in this game of reintroductions and restorations, and potentially could have a lot of impact, not just for that species but what we tell nurseries in the future,” he said.

PHOTO: Adrienne Basey with herbarium specimens.

Basey works with herbarium specimens

Basey is working with data collected over the past decade by research scientists at the Institute for Applied Ecology in Corvallis, Oregon, and University of Washington herbarium specimens from Washington and Oregon dating as far back as the 1890s, and data she has collected from existing plants during field work. “It’s a perfect partnership,” said Dr. Fant, who noted that the Garden is guiding the molecular aspect of the study while colleagues in Washington and Oregon are providing a large portion of the data and samples.

The availability of all of this information on a single species that is undergoing restoration is very rare, explained Fant. “It’s a very unique scenario that she has there, so we can look at how diversity changes as we go from step to step and hopefully identify any potential issues and where they are occurring in the process.”

The study itself will likely serve as a research model for other species in the future. “There isn’t much research out there to help propagators understand when and where genetic diversity may be lost during the production process,” said Basey’s co-advisor and conservation scientist at the Garden, Andrea Kramer, Ph.D.

Last year, Basey, Fant, and Kramer worked together to write a paper outlining ten rules to maximize and maintain genetic diversity in nursery settings. “My goal is to support reintroduction efforts by informing nursery practices and demonstrate to nurseries on a broader scale how their practices can influence genetic diversity through a single case study,” said Basey.

A Green Light Ahead

Her preliminary research is focused on four golden paintbrush populations. Early evaluations show clear distinctions between a few of them, which is good news. Basey will next compare those genetic patterns to those of plants in reintroduction sites.

According to Fant, earlier studies by other researchers have shown that many restoration efforts for threatened species suffer from low levels of genetic diversity prior to reintroduction, due to a number of causes ranging from a small population size at the outset to issues in propagation. It is critical to work around those issues, he explained, as the more genetic diversity maintained in a population, the better equipped it is to survive environmental changes from drought to temperature shifts.

Basey will also compare the current level of diversity of golden paintbrush to that of its historic populations, to get a better sense of what the base level should be for reintroduction success. She plans to wrap up her lab work well before her summer 2015 graduation date.

PHOTO: A golden paintbrush is visited by its primary pollinator, a bumblebee.

A golden paintbrush is visited by its primary pollinator, a bumblebee.

For now, she is pleased with the level of diversity she sees in the current population. “I think the fact that it has a high genetic diversity means that these reintroductions could be successful,” she said. “But if we are creating a bottleneck, we need to know that so we can mitigate it as quickly as possible.” (A bottleneck is an event that eliminates a large portion of genetic variability in a population.)

Fant is enthusiastic about the timing of the study as the field of restoration is taking off. “We can jump in early as programs are being started,” he noted. “If we all learn together, I think it really does ensure that everyone gets what they need in the end.”

For Basey, it’s about building a bridge between the theoretical and the applied aspects of restoration. “My interest isn’t so much in this single species but more in the communication of science to practitioners. I like to bridge the line between research and the people who are using research,” she said.

Basey, like the golden paintbrush, is looking toward a bright future.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

I’m a conservation scientist here at the Chicago Botanic Garden. I have an incredible job that allows me to work with many wonderful graduate students and a team of researchers to study ways to restore natural areas in the Colorado Plateau.

If you’ve ever visited national parks like the Grand Canyon or Arches, you’ve experienced at least some of what the Colorado Plateau (also known as the Four Corners region) has to offer. It includes more than 80 million acres across Utah, Colorado, New Mexico, and Arizona—and the largest concentration of national parks in the country.

PHOTO: Andrea Kramer in the Colorado plateau.

Our research team heads out across a recently-burned area in search of data.

Although beautiful, the Colorado Plateau’s natural areas are facing many threats, including wildfires, a changing climate, and destructive invasive species such as cheatgrass (Bromus tectorum) and Russian knapweed (Acroptilon repens). Working with many partners, including the Bureau of Land Management, we are studying which native plants may be best able to handle these growing threats (we refer to them as “native winners”). The ultimate goal is to help make restoration of these plants and habitats as effective as possible in order to maintain healthy natural areas that support wildlife and pollinators, and help keep our air and water clean.

PHOTO: Andrea Kramer at Rio Mesa.

Another beautiful day at Rio Mesa

This is no small task. The invasive species that the native plants are up against are very impressive. For example, Russian knapweed is allelopathic (prevents other plants from growing nearby), and it has roots that can grow more than 20 feet deep, seeking the water table. Fortunately, some native species are also able to grow in these conditions, and some even appear to be evolving and adapting to be better competitors.

Three Northwestern University graduate students are working with me. Master’s student Nora Talkington is testing how different populations of a native grass are able to compete with Russian knapweed, while doctoral student Alicia Foxx is researching how different root structures of native plants help them compete with invasive species. Master’s student Maggie Eshleman is studying six native wildflower species including the smallflower globe mallow (Sphaeralcea parvifolia), which has tiny, fiery orange flowers. These wildflowers are likely “native winners” and are strong candidates for increased use when restoring habitat in the Colorado Plateau.

A rainbow of wildflowers for restoration:

  • Tansy aster (Machaeranthera canescens): This purple-flowered plant is good for pollinators, one of the few plants that flowers late in the season, and on top of that, is really good at growing in sites that need to be restored.
  • Woolly plantain (Plantago patagonica): This cute little annual plant is often the only thing we find flowering and producing seeds during extreme drought years. It is very impressive!
  • Bee plant (Cleome lutea): This annual plant has gorgeous yellow flowers. It’s good at growing in disturbed areas and, as its name indicates, is a great forage plant for bees.
PHOTO: Cleome lutea.

Bee plant (Cleome lutea) by Andrea Kramer

PHOTO: Sphaeralcea parvifolia.

Smallflower globe mallow (Sphaeralcea parvifolia) by Andrea Kramer

PHOTO: Machaeranthera canescens.

Tansy aster (Machaeranthera canescens or Dieteria canascens) by Maggie Eshleman

PHOTO: Plantago patagonica.

Woolly plantain (Plantago patagonica) by Andrea Kramer

This summer was a busy one. My students and I spent many weeks in the Colorado Plateau working with collaborators to collect seeds (as part of Seeds of Success collectors—a national native seed collection program). These seeds are now being used for studies in the Garden’s research greenhouses and growth chambers, and at study plots in Utah, Arizona, and Colorado. In the Garden’s Daniel F. and Ada L. Rice Plant Conservation Science Center, we are also using incubators to create spring- and summer-like conditions that will help us understand when and why seeds of certain species are able to germinate and grow. This is an important aspect of ultimately being able to restore species in a degraded habitat.

PHOTO: La Sal mountains in the background; the plains abloom in May.

La Sal mountains in the background; the plains abloom in May

How cool is it to be able to take research that’s been done on a small scale and actually apply it to the real world? I feel so lucky to be able to do this work, and being here at the Chicago Botanic Garden has allowed me to build long-term partnerships that investigate the application of research, rather than just focusing on publishing it. Stay tuned for updates on how these native winners perform.


This post was adapted from an article by Nina Koziol that appeared in the winter 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

©2014 Chicago Botanic Garden and my.chicagobotanic.org