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Undercover Science

Treasure in the Tropics

Julianne Beck —  October 9, 2013 — Leave a comment

Hungry for progress, Nyree Zerega, Ph.D., set off in early June to the forests of Sabah, Malaysia, on the island of Borneo.  She was searching for plants in the genus Artocarpus, whose nearly 70 species include jackfruit—the world’s largest tree-borne fruit structure.

Her mission? To gather detailed information about species within the genus, including those that could provide food in tropical areas where it is needed most.

PHOTO: Dr. Zerega and Dr. Joan Pereira climbing hill in tropical forest.

Dr. Zerega in Sabah with Dr. Joan Pereira, her Malaysian collaborator.

On their research trip this summer, Dr. Zerega, a plant evolutionary biologist at the Chicago Botanic Garden, and her research team crossed a small stream on their way into a tropical forest on the edge of a large oil palm plantation. They searched there for an uncommon species until sunlight faded and the light rain turned to a downpour. On the way back, they found that the stream had grown into a raging river several feet wide and deep. Covered in leeches, they held hands tightly and waded across to safety. On other days, they searched for species with leaves as tall as any one of them, and collected fruit weighing more than 20 pounds apiece.

The dish

It’s all in a day’s work for Zerega. She has long traveled to places like this, where she works closely with local scientists to study underutilized food-bearing plants.

PHOTO: Jeisn Jumian with a huge jackfruit over one shoulder, and a cut jackfruit in his other arm.

Jeisn Jumian, field assistant, carries jackfruit back from the field for dinner.

Currently, she explained, the world relies on roughly 30 species to provide the majority of our food. The top three crops—rice, corn, and wheat—account for approximately 40 percent of all food consumed worldwide. We are merely scratching the surface of the thousands of edible plant species in existence, including at least a dozen in the genus Artocarpus.

It’s possible, even likely, that some underutilized crops have as much potential as the current favorites, but simply have not been as developed. “Underutilized crops have the potential to diversify the world’s food supply and improve food security,” said Zerega. She believes the development of these crops, produced close to where they would be consumed, could also reduce the amount of energy used in growing and exporting large quantities of crops around the world. The more options we have, the better off we are, she maintains.

Stocking the pantry

Now back in the Harris Family Foundation Plant Genetics Laboratory of the Daniel F. and Ada L. Rice Plant Conservation Science Center, Zerega and her lab members are busy extracting plant DNA from leaves collected in Malaysia. Also the director of the Northwestern University and Chicago Botanic Garden Graduate Program in Plant Biology and Conservation, she has plenty of helping hands from her master’s and doctoral students.

“We’ll be studying DNA to understand the evolution of Artocarpus, and patterns of the diversity of cultivated members of the genus, such as jackfruit, breadfruit, and the lesser known cempedak, a species believed to have originated in Malaysia. Understanding and conserving genetic diversity is as critical in crop species as it is in wild species,” she said.

PHOTO: The market in Sabah, Malaysia.

Breadfruit is sold at a market in Sabah, Malaysia.

The work is part of a National Science Foundation grant for which Zerega is assembling a taxonomic revision, which is like a genealogical history. It will include descriptions of all the Artocarpus species, how to identify them, where they originated, where they are found today, how they are used, and how they are related to one another.  

Dried, pressed specimens of all the plant samples used for DNA will be stored in herbaria in Malaysia and the Garden’s Nancy Poole Rich Herbarium. Zerega serves as director of the herbarium. These specimens, along with photographs, serve as documentation of each plant.

Cooking up solutions

PHOTO: A plate of fried breadfruit with dipping sauce.

Fried breadfruit from a market near Kuala Lumpur, Malaysia.

Next, Zerega hopes “to focus on ways to conserve the diversity and increase the use of underutilized species such as jackfruit and breadfruit, because they hold great potential for increasing food security in food-insecure parts of the world, many of them in tropical areas where Artocarpus species grow.”

As she considers her research, Zerega occasionally finds time to stroll her favorite areas of the Garden—the Dixon Prairie and the McDonald Woods.

From working with students and collaborating with scientists around the world, she hopes her work will contribute to the conservation of underutilized crop diversity and food security around the world. Although she has already accomplished a great deal, it seems that Zerega’s work so far is just a taste of what is to come.

Read more about Zerega’s research in Papua New Guinea, the Northern Mariana Islands, Hawaii, and Bangladesh in the Spring 2013 issue of Keep Growing.


©2013 Chicago Botanic Garden and my.chicagobotanic.org

The Evolution of a Research Idea

Krissa Skogen finds inspiration in the relationship between moths and evening primroses

Krissa Skogen —  October 7, 2013 — 1 Comment

Five years ago this past May, I found myself starting a new job and a new research project. My job, of course, was as a conservation scientist here at the Chicago Botanic Garden, and the research project had me sitting on the side of a road at dusk in Pueblo West, Colorado. I sat there in front of a group of plants that produce lovely-smelling flowers, waiting for their impressive pollinators to show up. And when they did, I snapped some of my very first photos of these beauties: hawkmoths, better known as the five-spotted hawkmoth, or to the scientific community as Manduca quinquemaculata.

PHOTO: Night photo of hawkmoth sipping nectar from evening primrose.

A five-spotted hawkmoth (Manduca quinquemaculata) drinks nectar from the Colorado Springs evening primrose (Oenothera harringtonii) as the flower begins to open. Pueblo West, Colorado, May 2008. Photo: Krissa Skogen

Just this past Friday, I visited the National Science Foundation’s Dimensions of Biodiversity Program, to find this very same photo—and the research that my colleagues and I will conduct over the next five years—highlighted.

So how did this one photo go from being taken in the spring of 2008 to being highlighted on the NSF’s website? How does a research project evolve and grow over time? Ask any scientist what they are currently working on and their answer will almost always start with, “I was first fascinated by x back in y….” Something caught their attention, sparked a thought, pulled them in—and they continued asking question after question, developing hypotheses and gathering data to test them, with their answers pushing them forward, sometimes down unanticipated paths, and sometimes into much bigger or smaller arenas. The more one knows, seemingly, the less one knows; old questions are answered and new ones are developed. This is what pushes scientists, and science, forward.

The evolution of a research idea

PHOTO: Krissa Skogen poses with primrose in New Mexico.

Krissa Skogen poses with an evening primrose in New Mexico. Photo: Chris Martine

In 2008, I started my current research program. After many conversations with Rob Raguso (Cornell University) and Tass Kelso (Colorado College), I drove out to Colorado with a plan to collect as much information on as many different populations of the Colorado Springs evening primrose (Oenothera harringtonii) as possible in a short period of time. That year, my timing was off—I arrived in Colorado on June 10. Oenothera harringtonii flowers primarily in May. Most of the plants had stopped flowering and so instead of collecting data on floral features, nectar, scent, and pollinators, my field assistant, Evan Hilpman, and I collected data on plant size, health, reproductive success (how many fruits did they produce?) and population size (much like a census). And one striking thing we noticed was this: small white “galls” on some of the green, developing fruits. We took notes on how often we saw this, never anticipating the importance that these little white dots would play in just a few years’ time.

PHOTO: Closeup image of a tiny, white foamy-looking dot (one of many) on a host plant.

We noticed small white “galls” on some of the green, developing fruits. These are parts of the cocoons of tiny little moths, called microlepidopterans, of the genus Mompha. Photo: Krissa Skogen

In subsequent years this project grew, and in the last four years—with the help of conservation scientist Jeremie Fant and other colleagues, and many research assistants and students—we’ve collected data on flower size, nectar volume and sugar content, floral scent, who pollinates and when (hawkmoths come at dusk and visit overnight; bees generally visit in the morning), how populations grow and shrink over time, which other plant species are flowering at the same time, and more. We know a lot of things about this species now, and one thing has been a constant: those little white balls have been observed year-in and year-out in some populations, but not in others.

We know now that some of our populations have an important compound—linalool—and some do not. We know that genetically speaking, our 25 populations function more like three, likely due to the fact that hawkmoths can fly so darn far (some estimates are up to 20 miles in just one night). And more recently, we started gathering more data on those little white balls. It turns out that they are parts of the cocoons that surround the larvae of tiny little moths called microlepidopterans, which belong to the genus Mompha. These moths lay their eggs on flower buds, fruit, and stems. If the larvae eat flower buds and/or seeds, they reduce the number of offspring that the plant produces. This is bad for any plants upon which these moths decide to lay their eggs, but everything must eat, right?

PHOTO: Trio of photos of each life stage of the moth: adult, larva, and cocoon.

Mompha stellella microlepidopteran adult; larva inside fruit (seed predator); cocoon inside O. harringtonii fruit. Photos: Terry Harrison and Krissa Skogen

In speaking with colleagues across the country and in Canada (plant and moth experts, alike), we developed an intriguing story and series of hypotheses we felt were compelling. Do pollinators and floral antagonists both respond to the same attractive scent? Could floral scent be telling hawkmoths and Mompha moths where the flowers are? Pollination is good for plant reproduction, but anything that eats flowers or seeds is not—so how would this trade-off play out in evolutionary time?

These questions have led us to the project that we will pursue on a much larger scale, thanks to recently awarded funding from the National Science Foundation’s Dimensions of Biodiversity Program for our proposal, titled “Landscapes of linalool: scent-mediated diversification of flowers and moths across western North America.”

PHOTO: Bee coated in pollen, inside primrose bloom.

A Lasioglossum species bee robbing pollen from O. harringtonii at dawn. Photo: Sadie Todd

Relationships among flowering plants and insects represent one of the great engines of terrestrial diversity. Floral scent and other plant volatiles are important drivers of these relationships (e.g., pollination, herbivory, plant defense), but remain poorly integrated into floral evolution and pollination ecology. Few studies have tested the spectrum of plant fitness outcomes when scent attracts both pollinators and floral/seed enemies. Thus, the hidden diversity of floral/seed predators and their potential as selective agents constitutes a considerable gap in pollinator-centric understanding of floral evolution. These “forgotten predators” have co-diversified with flowering plants and are likely influential in the evolution of most plant-pollinator interactions.

PHOTO: Five-spotted hawkmoth extending its proboscis (longer than its body) into a primrose bloom as it hovers.

A five-spotted hawkmoth (Manduca quinquemaculata) probes an opening evening primrose flower for nectar with its proboscis. Photo: Krissa Skogen

This project is ambitious and large and pulls upon a wide variety of expertise. In total, there are 11 Ph.D. scientists collaborating on it, including myself, Jeremie Fant, and Norm Wickett here at the Garden. The others include Robert Raguso (Cornell University), Rachel Levin (Amherst College), Terry Harrison (University of Illinois at Urbana-Champaign), Jean-Francois Landry (Agriculture & Agri-Food Canada, Eastern Cereal and Oilseed Research Centre), Sylvia (Tass) Kelso (Colorado College), Kathleen Kay (University of California, Santa Cruz), Mike Moore (Oberlin College), and Warren Wagner (Smithsonian Institution).

We are excited about what we’ll uncover in the next five years and will update you with progress as our discoveries unfold!


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Simulating Summer in the Plant Science Center

Getting seeds to reveal their secrets

Andrea Kramer —  February 25, 2013 — Leave a comment
Seeds of potential native winners from the Colorado Plateau.

Seeds of native species from the Colorado Plateau.

These seeds may not look like much right now, but the story they tell is full of adventure and promise. This week we are simulating summer in the Daniel F. and Ada L. Rice Plant Conservation Science Center to get them to reveal some of their secrets.

My research takes me to the Colorado Plateau (you may know it as the “four corners” region), which is one of the most starkly beautiful places in the United States. I work with many Garden scientists, graduate students, and public land management agencies like the Bureau of Land Management (BLM) to carry out research that helps make native plant restoration and management on public lands throughout the Colorado Plateau as efficient and effective as possible. We are particularly focused on understanding how to help native plants cope with encroaching invasive species, changing land use, and shifting climates.

So these seeds come from a gorgeous place. But more importantly, they were produced by some pretty impressive native plants that were tough enough to not only survive last year’s crazy weather, but to also flower and produce seeds in some pretty harsh sites. Like Chicago, the Colorado Plateau experienced one of the hottest, driest summers it has seen in a long time. Most of the plants in the Colorado Plateau sat out the flowering season last year — they conserved their resources for a better year. We are interested in the plants that braved really bad conditions to produce seeds, because we think they will be especially useful when restoring habitat that has been badly damaged by wildfire or invasive species. We call these plants native winners.

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Unfortunately, very little is known about what makes these native winners tick. Our research is helping to uncover some of their secrets. Alicia Foxx (a student in our joint graduate program with Northwestern University) and I have just set up an experiment that will reveal the specific seed germination requirements for these native winners. We are using incubators that allow us create spring- and summer-like conditions that will tell us when and why seeds of these species are able to germinate and grow. Knowing this information is just a first step in our research that will help us improve the outcome of restoration practices.


©2013 Chicago Botanic Garden and my.chicagobotanic.org