_{|  Story by Cindy Cain  |}

_2/17/2022

Chokeberry seeds that were plucked from the Forest Preserve District's Kankakee Sands Preserve in Custer Township last year are now being stored in two national seed vaults.

The Kankakee Sands specimens are among leaf tissue and seeds collected from four Illinois sites. The genetic materials will be used for research projects and stored for safekeeping in a seed bank at the North Central Regional Plant Introduction Station in Ames, Iowa, as well as at the National Laboratory for Genetic Resources Preservation in Fort Collins, Colorado, which is a long-term, backup storage facility.

The leaf tissue samples were placed in packets with silica beads, freeze dried and tucked into sealed, air-tight packets that are now being stored in a room at 5 degrees Celsius (41 degrees Fahrenheit). The chokeberry seeds are stored in re-sealable, thick-plastic, see-through packaging being kept at a cool minus 18 degrees Celsius (minus 0.4 Fahrenheit) in a large walk-in freezer.

Additional seeds grown from some of the Illinois samples could, eventually, go to the Svalbard Global Seed Vault in Norway. The Norway facility offers, “safe, free and long-term storage of seed duplicates from all genebanks and nations participating in the global community’s joint effort to ensure the world’s future food supply.”

Seed collecting is part of national and international programs designed to preserve genetic materials should there be natural or human-caused disasters that harm or eliminate species and reduce the planet’s biodiversity. The samples also are protected and prepped for use by scientists as they work to create disease-resistant species.

Why chokeberry?

Horticulturist Jeffrey Carstens led the team to Illinois in May and August 2021 to collect the seeds and plant materials. He works for the Ames facility, which is a collaboration between Iowa State University and the U.S. Department of Agriculture's Agricultural Research Service. The USDA operates 20 seed banks in the United States known as the U.S. National Plant Germplasm System. The Ames seed vault was the first in the nation when it opened in 1948.

In 2021, the Ames group was searching for aronia, commonly known as chokeberry, because the vault was missing Midwestern variants of this plant. The foray was organized with help from the Illinois Natural History Survey, which records the location of the state’s many flora and fauna species.

“Historically speaking, we have a very good collection of aronia, but it’s focused on most of the New England states or the eastern portion of the U.S.,” Carstens said. “We had very little genetics in our holdings that are of Midwestern origin and were basically filling a collection gap.”

Chokeberries have become a common alternative crop in agriculture, Carstens said. He said a hybrid of the aronia berries can be found in some grocery stores in late summer and it is often added as a natural food coloring to frozen fruit juice products.

Chokeberry fruit is desirable because it has a high level of antioxidants, higher than blueberries, for instance. Chokeberries also are more commonly being used as a beneficial landscaping choice.

“It provides early spring flowers for pollinators along with nice foliage, followed by fruits providing food for birds and then you get nice fall color,” Carstens said. “And it’s a shorter shrub, it doesn’t get large, so it fits that niche of small plants for the home landscape.”

Illinois samples

In addition to Kankakee Sands Preserve, the group sampled chokeberry plants at Starved Rock State Park in La Salle County, the Iroquois County Conservation Area in Iroquois County and Rutland Township Bog in Kane County.

“The further apart we can get our collections, the more likely we’re going to get genetic diversity, which is our whole goal,” Carstens explained. “You could get on the Internet and buy chokeberry and it could be coming from Maine or New Jersey or Indiana or Ohio, but those genetics are very different from what you have in Illinois. They might leaf out too early or too late or they may not be adapted to the particular soils or be cold-hardy enough.”

The source is extremely important in determining what we put back in the landscape, he said.

“I always tell people, you would never want to purchase a bur oak that originated from Texas and plant it in Minnesota, you’re just asking for failure. I don’t think a lot of people realize how important that is and how much that influences the performance of a plant.”

Around 3,500 seeds collected from Kankakee Sands Preserve and Rutland Township Bog were shipped to the Fort Collins seed vault to back up the seeds being stored in Ames. Additional seeds collected from Starved Rock State Park and the Rutland Township Bog will be grown in a very carefully controlled-pollination environment.

“When we plant those in our plots, we will control pollinate those, so no other genetics are getting into that group of plants,” Carstens said. “So, you basically take 100 seeds and turn them into 100,000 seeds and that usually takes four to five years.”

Some of those seeds will be made available for research, crop improvement and product development.

‘Amazon’ of plants

The materials Carstens and his colleagues collect is known as germplasm, which is plant materials, including seeds and cuttings, that can be regenerated into a whole plant and that carry desired genes and gene combinations.

Some of the collected leaf germplasm is made available to scientists who can order the items they need for their research.

“We can send them small, small samples of dried leaves and they can use that for genetic analyses,” he said. “As opposed to them having to drive to your location and sample (the plant) themselves, we’ve done that prep work for them. We’re basically the Amazon of plant genetics.”

The aronia seed collection wasn’t the only trip Carstens and his colleagues made last year. They also collected white pine seeds from Iowa. This year they plan to collect elms in Missouri, bee balm in Texas, and western ash species in Arizona and New Mexico.

“It’s a daunting task,” Carstens said of his seed collection quest. “I’m pushing close to 1,000 collections I’ve made so far. Mostly it’s been ash trees because of emerald ash borer.”

Carstens and his team haven’t found a species resistant to the destructive and invasive emerald ash borer yet, “But at least we have the genetics to work with,” he said.

Critical genes

Floyd Catchpole, the Forest Preserve District’s land management program coordinator, helped Carstens' team know where to search for aronia before the group arrived at Kankakee Sands last year. Catchpole said seed collection and preservation are more important now than ever before.

“For example, in the past, it has been easy to go to wild potatoes to find the genes that protect cultivated potatoes against late blight, which killed a million people in the Irish Potato Famine,” he said. “But as local populations of plants die out, they may take critical genes with them. That is one reason why it is important to preserve plant genetics in seed banks.”

The chokeberry seeds collected by the Iowa group currently have few horticultural diseases or pests.

“But the same could have been said of the potato two hundred years ago,” Catchpole said.

_{(Lead image of chokeberries courtesy of Jeffrey Carsten)}