URBANA, Ill. – Today’s soybeans are typically golden yellow, with a tiny blackish mark where they attach to the pod. In a field of millions of beans, nearly all of them will have this look. Occasionally, however, a bean will turn up half-black, with a saddle pattern similar to a black-eyed pea.
”The yellow color is derived from a natural process known as gene silencing, in which genes interact to turn off certain traits,” explains Lila Vodkin, professor emerita in the Department of Crop Sciences at the University of Illinois. “Scientists make use of this process frequently to design everything from improved crops to medicines, but examples of naturally occurring gene silencing – also known as RNA interference, or RNAi – are limited. A better understanding of this process can explain how you can manipulate genes in anything from soybeans to humans.”
The RNAi pathway was discovered about 20 years ago as a naturally occurring process in a tiny roundworm. The discovery and follow-up work showing its biomedical potential won scientists the Nobel Prize in 2006. In plants, RNAi was discovered in petunias. When breeders tried to transform one gene to cause brighter pinks and purples, they wound up with white flowers instead. The gene for flower color had been silenced.
“Before they were domesticated, soybeans were black or brown due to the different anthocyanin pigments in the seed coat,” says Sarah Jones, a research specialist working with Vodkin on the study. “Breeders got rid of the dark pigments because they can discolor the oil or soybean meal during extraction processes.”
Vodkin clarifies, “The yellow color was a naturally occurring RNAi mutation that happened spontaneously, probably at the beginning of agriculture, like 10,000 years ago. People saw the yellow beans as different. They picked them up, saved them, and cultivated them. In the germplasm collections of the wild soybean, Glycine sojae, you don’t find the yellow color, only darkly pigmented seeds.”
Previous work from the team showed that yellow soybeans result from a naturally occurring gene silencing process involving two genes. Essentially, one of the genes blocks production of the darker pigment’s precursors. But the researchers weren’t sure why black pigments sometimes reappear, as in saddle-patterned beans. Now they know.
Vodkin and her team searched for beans with unusual pigmentation in the USDA soybean germplasm collection, housed at U of I. The collection contains thousands of specimens, representing much of the genetic diversity in domesticated soybean and its wild relatives.
“We requested beans with this black saddle pattern,” Jones recalls. “We wanted to know if they all get this pattern from the same gene.” Some of the samples had been collected as far back as 1945.
The team used modern genomic sequencing techniques, quickly sifting through some 56,000 protein-coding genes to identify the one responsible for the pattern. The lead author, Young Cho, made the discovery as a graduate student when he noticed a defect in the Argonaute5 gene. The team looked at additional beans with the saddle and found that the Argonaute5 gene was defective in a slightly different way in each of them.
“That’s how you prove you found the right gene,” Vodkin says, “because of these independent mutations happening at different spots right in that same gene.”
When the Argonaute5 gene is defective, the silencing process – which normally blocks the dark pigment and results in yellow beans – can no longer be carried out. The gene defect explains why the dark pigments show up in the saddle beans.
Before the team’s discovery, there were very few examples of how gene interactions work to achieve silencing in naturally occurring systems. Today, bioengineers use genetic engineering technologies to silence genes to produce a desired outcome, whether it’s flower color, disease resistance, improved photosynthesis, or any number of novel applications.
“The yellow color in soybeans could have been engineered, if it hadn’t occurred naturally,” Vodkin says, “but it would have cost millions of dollars and every yellow soybean would be a genetically modified organism. Nature engineered it first.” She says this study also emphasizes the value of the soybean germplasm collection, which preserves diversity for research and breeding purposes.
The article, “Mutations in Argonaute5 illuminate epistatic interactions of the K1 and I loci leading to saddle seed color patterns in Glycine max,” is published in The Plant Cell. The study’s lead author, Young Cho, is now a postdoctoral researcher for the Institute of Genomic Biology at the University of Illinois. The work was funded by the United Soybean Board, the USDA, and the Illinois Soybean Association.
Foundation Supports Crops in Silico
The Foundation for Food and Agriculture Research (FFAR) has awarded Principal Investigator Amy Marshall-Colón, Assistant Professor of Plant Biology at the University of Illinois, $274,000 to continue her research in support of Crops in silico (Cis), a project to develop a suite of virtual plant models that may help resolve a growing gap between food supply and demand in the face of global climate change. She is collaborating with Stephen P. Long, Gutgsell Endowed University Professor of Crop Sciences and Plant Biology.
As the planet warms, growing environments around the world are changing faster than traditional crop breeding programs can create new well-adapted varieties. Fully realized, Cis will give crop researchers a tool to examine the effects of environmental challenges on a molecular, cellular, and organ level within a plant to determine the best targets for genetic engineering.
“Science is accelerating faster than ever before, and the Foundation for Food and Agriculture Research is committed to harnessing cutting-edge science for the benefit of the agricultural system,” FFAR Executive Director Sally Rockey said. “Crops in silico will integrate some of today’s most advanced plant models, providing new and exciting insights into how a plant functions that will undoubtedly accelerate our ability to improve plants. I look forward to the results of this exciting project.”
The ability to computationally mimic the growth, development, and response of crops to the environment will allow researchers to conduct many more experiments than can realistically be achieved in the field.
Marshall-Colón will collaborate with Long; Matthew Turk, Assistant Professor of Information Sciences, Assistant Research Professor of Astronomy and National Center for Supercomputing Applications (NCSA) Research Scientist; Christine Kirkpatrick, Executive Director of the National Data Service; and Jonathan Lynch, University Distinguished Professor of Plant Science at Penn State University.
The team will work to integrate above- and below-ground models of plants to create never-before-seen “whole views” of them. Then, they will subject these newly built virtual plants to computer-simulated extreme growing conditions — from flood to severe drought to increased ambient carbon dioxide — and compare the model’s predicted plant reaction to observed responses from field studies. This will help “dial in” the model’s accuracy.
Beyond a technological breakthrough, the Cis team also aims to achieve a research community shift.
“We believe Crops in silico will unite largely isolated efforts into a connected and collaborative community that can take full advantage of advances in computation science and mechanistic understanding of plant processes and their responses to the environment,” Marshall-Colón said.
The Crops in silico project was seed-funded in 2015 by a $350,000 grant from the Institute for Sustainability, Energy, and Environment (iSEE) at the University of Illinois at Urbana-Champaign awarded to Long. NCSA recently awarded additional seed funding for Cis to Turk. The awards from iSEE and NCSA will provide matching funds to support the Cis team and its work under the FFAR grant, the first given to a University of Illinois researcher.
The Foundation for Food and Agriculture Research, a 501(c)(3) nonprofit organization established by bipartisan congressional support in the 2014 Farm Bill, builds unique partnerships to support innovative and actionable science addressing today’s food and agriculture challenges. FFAR leverages public and private resources to increase the scientific and technological research, innovation, and partnerships critical to enhancing sustainable production of nutritious food for a growing global population. The FFAR Board of Directors is chaired by Mississippi State University President Mark Keenum and includes ex officio representation from the U.S. Department of Agriculture and the National Science Foundation. Learn more at www.foundationfar.org.
URBANA, Ill. – Most gardeners are aware that plants need water to thrive, but it can be helpful to review the ins and outs of garden hydration to ensure the best results.
“Many environmental conditions factor into plant survival,” says Andrew Holsinger, a University of Illinois Extension horticulture educator. “Hydration is one of the most important of those factors.”
Plants vary in their moisture requirements, but as a general rule, vegetable crops require at least an inch of water per week. Excessively hot or windy days may require more frequent irrigation because more water is lost from the plant. Holsinger says too little water can cause not only drought stress but also increased disease or insect susceptibility.
Mulch can help conserve moisture and reduce the plant’s demand for more water. For plastic mulches, the plants will need to be irrigated regardless of rainfall events. Water does not readily penetrate beneath the plastic, so it is often necessary to add drip irrigation under the plastic.
“Putting moisture in the right place, where the plant is located, is also a way to reduce weeds because you’re not providing water where it isn’t necessary,” Holsinger says.
Drip irrigation delivers water to the base of the plant instead of on its foliage. Gardeners should avoid excessive water application on leaves to avoid fungal pathogens and diseases, some of which can cause wilting. Surprisingly, overwatering can also cause wilting, so be sure to check the soil before watering.
“For most plants in the garden or landscape, a well-drained soil is required. However, in some spaces where drainage may be an issue, a raised bed can help increase drainage,” Holsinger says. “Raised beds can be used for both ornamental and edible crop plantings.”
Containers can be great for growing, but they need adequate drainage holes. A more frequent watering schedule is required for containers, as they tend to dry more quickly than garden beds.
“It’s rare in Illinois to see consistent precipitation throughout the season, and an attentive gardener is aware of it,” he says. “Your watering schedule will have to be adjusted over the season.”
As plants mature, they require more water. Therefore, if you have a limited amount of water available to dedicate to your garden, you may want to plan. Setting up zones based on water use can help to distribute water at appropriate levels to plants based on their cultural requirements.
Suspect herbicide drift? U of I Extension has answers
URBANA, Ill. – Every year the Illinois Department of Agriculture (IDOA) receives approximately 72 complaints of crop damage due to pesticide drift. When drift occurs, it is important to know the basics of the complaint process as well as the available resources.
“Neighborly discussions before pesticides are applied are a good idea so applicators are aware if sensitive plants are growing near the application site,” says Aaron Hager, weed scientist in the Department of Crop Sciences at the University of Illinois. “Before doing anything, both parties should make an effort to discuss the suspected drift incident and rule out other possible causes of the damage. In cases where the cause of the damage remains unclear or where the parties will not work together, a formal complaint may be necessary.”
The IDOA and University of Illinois Extension each have important roles in assisting Illinois citizens in dealing with pesticides. The IDOA administers and enforces laws related to pesticide use and U of I Extension assists to educate and solve problems.
If pesticide drift is suspected, you may send affected plant samples to the U of I Plant Clinic. “Be sure to include as much relevant information as possible,” says Michelle Wiesbrook, an Extension specialist in the Pesticide Safety Education Program.
Because the Plant Clinic does not perform pesticide residue tests, the cause of a symptom cannot be attributed to pesticide drift with 100 percent certainty. However, it is possible for clinic staff and specialists to rule out other possible causes and establish whether pesticide drift is the likely cause.
The IDOA has three roles that impact its handling of pesticide-drift complaints. These roles are (1) education and licensing of applicators and operators via the Pesticide Safety Education Program, (2) investigation of complaints, and (3) enforcement of pesticide laws. The roles of IDOA are determined by laws and statutes passed by the Illinois legislature or the federal government.
“If you choose to file a complaint with IDOA, time is of the essence,” Hager says. “Complaint forms must be received by IDOA within 30 days of the incident or within 30 days of when the damage was first noticed. Complaints filed after that will be kept on record, but no administrative action can be taken.”
The process begins when farmers fill out a pesticide drift complaint form, which can be found at http://go.illinois.edu/complaintform or by calling IDOA’s Bureau of Environmental Programs at 1-800-641-3934 (voice and TDD) or 217-785-2427.
The complaint process
Once a complaint is filed with the department, a field inspector is assigned the case. In most cases, the inspector will interview the complainant and inspect the site. Various types of samples, such as plants, water, or soil, may be collected for analysis at an approved laboratory.
The inspector may also interview applicators in the area, examine pesticide records, and collect weather data in an attempt to determine the nature and cause of the damage. The field investigator will then submit a report to IDOA for review.
Both parties will receive written notification if IDOA finds a violation and takes an enforcement action. Penalties range from advisory or warning letters to monetary penalties of $750 to $10,000, depending on the type and severity of the violation. Penalties are determined through a point system defined in the Illinois Pesticide Act.
Even if a violation of the Illinois Pesticide Act cannot be substantiated, both the complainant and the alleged violator will be notified in writing of the complaint’s status. The department’s role in pesticide misuse incidents is limited to determining whether a violation has occurred, and cannot help complainants recover damages.
“Certainly, it is easiest and best to prevent herbicide drift from occurring in the first place,” Hager says.” Drift can be extremely expensive and often results in poor neighbor relations.”
Additional information for use when handling potential drift injury
A useful resource that includes information and helpful tips on preventing and dealing with the off-target movement of herbicide applications is an online module titled, “Herbicide Tolerant Crop Stewardship”.
“While it was created with producers in mind, it would also be beneficial to homeowners, gardeners, and anyone who grows plants, and it’s free,” Wiesbrook says.
Creating a butterfly oasis
URBANA, Ill. – There are approximately 2,000 species of butterflies and moths native to Illinois, and creating a butterfly oasis can bring them to your backyard.
“One of the things to remember when creating a butterfly oasis is to provide both nectar sources for butterflies and larval food sources for caterpillars,” says University Extension horticulture educator Kari Houle.
In addition to providing food sources, Houle says that planning a butterfly oasis requires careful plant and fixture selection for the garden.
“Plan for continuous season-long blooms, provide resting spaces, minimize pesticide use, and be willing to accept some plant damage due to larval feeding. Choose a sunny location that is protected from wind,” she says.
Gardeners should also provide opportunities for “puddling,” when male butterflies visit mud puddles for water and minerals. “Mimic mud puddles in your garden by providing a tray with wet sand and some sticks and rocks for the butterflies to land on,” Houle says. “Make sure to check the puddling tray regularly to ensure the sand hasn’t dried out.”
It’s a good idea to include large flat stones or other landing surfaces in the sun so that cold-blooded butterflies can bask and collect heat from the sun.
When planning the butterfly oasis, use large masses of color instead of small color pockets because butterflies are short-sighted. Consider the flowers’ colors when choosing plants. Butterflies prefer red, pink, or purple flowers, but they will also visit other colored flowers.
“One of the other important parts of successfully creating a butterfly oasis is to minimize pesticide usage,” says Houle. “Since we want to encourage both butterflies and caterpillars, many insecticides can be harmful to one or the other. Understand that a certain level of plant damage is necessary. Break out of the normal mindset of trying to prevent plant damage from insect feeding and allow it in your butterfly oasis.”
If you do have insect damage requiring attention, spot treating the issue instead of using broad-spectrum insecticides has multiple benefits. “Reducing insecticide use in the garden can have the added benefit of allowing the increase of beneficial insects and natural predators,” Houle says.
“My summer goal is to start a butterfly oasis in my backyard,” Houle says. “Will you join me?”
Garden flowers for the “dog days” of August
URBANA, Ill. – Every summer, gardeners notice that certain plants are beautiful up until the heat arrives. Then they fade and wither, leaving us with only the memories of what once was. To keep these plants looking good, watering becomes a nightmare during high heat and periods of no rainfall. Xeriscaping, or low-water-usage gardening, may be the answer.
"The term xeriscape often brings visions of parched desert landscapes,” explains Martha Smith, horticulture educator with University of Illinois Extension. "A xeriscape can be colorful, attractive, and inviting while requiring far less water than traditional landscapes."
By following a few basic tips, gardeners can use less water and still enjoy a colorful garden.
- Group plants according to water needs. Plant thirsty plants together to concentrate watering in specific areas, rather than “blanket” watering.
- Build soil lips or soil basins around plants to direct water to plant roots. Depending on plant size, this basin should be 3 to 18 inches from the base of the plant.
- Mulch gardens to retain soil moisture.
- Keep beds weed-free. Weeds take up water that could be used by desirable plant material.
- If your soil drains too quickly, amend it by adding moisture-holding organic matter.
- Pick the right plant for the right spot. Choose plants that thrive in hot, dry conditions.
Here are some popular blooming “dog day” plants:
- Celosia, or cockscomb (Celosia argentea), is unique for its unusual feathery or brain-like flowers of bright red, yellow, orange, and pink. Celosia is an annual that may grow from 6 inches to 4 feet tall, depending on the variety. Bring fresh cut celosia inside for an excellent cut flower, or hang it to dry.
- Spider flower (Cleome hassleriana) can reach 4 to 5 feet tall in full sun. The unique spider-like flowers are rose, violet, or white. Cleome is an annual, meaning it grows from seed every year. It will re-seed freely in your garden.
- Gomphrena, or globe amaranth (Gomphrena globosa), blooms in a variety of bright colors including purple, orange, red, rose, and pink. Generally the plant grows 1 to 2 feet tall. This is an old-fashioned flower that is easy to grow. It makes an excellent dried flower that holds its color well. Pick just as the flowers open fully and hang upside down to dry.
- Madagascar periwinkle, also known as annual vinca (Catharanthus roseus) is a plant that seems to thrive in hot areas. Its lush, dark green foliage is somewhat glossy and forms a 2-foot tall mound. Annual vinca is available in white, pink, purple, and bicolors. If you have a difficult southern exposure to work with, try this annual. It is slow to start if spring temperatures are cool and it does not tolerate wet areas.
- Threadleaf coreopsis (Coreopsis verticillata) is a perennial that will reach 18 to 24 inches in height. It has yellow, daisy-like flowers that last from late spring to late summer. This plant will grow best if planted in a dry, full-sun area.
- Orange coneflower (Rubdeckia fulgida) is the perennial form of blackeyed Susan. Its cheery yellow or orange daisy flowers brighten up the August garden.
- Blanket flower (Gaillardia species) is a perennial plant available in a variety of hot colors like golden yellow and mahogany red. Cultivars are available in a range of sizes with most growing in the 2-foot height range. Blanket flower tolerates dry soil and temperatures of 90 degrees Fahrenheit or higher.
“All of these plants will survive the hot days of August with very little attention and care, requiring only an occasional pruning off of old blossoms,” Smith says. “Try one or two next year and enjoy your garden all season long.”
Local foods: Food processing program, student farm allows campus to serve local and sustainably grown items
URBANA, Ill. – The tasty slices of pizza students will be eating this fall in University of Illinois dining halls will be as close to “locally grown” as most restaurants can get, with many of the ingredients grown right on campus.
Not only do students get to enjoy these home-grown products, but students are involved in every step of the process—from growing the tomatoes and wheat, to the processing and milling after harvest, and even developing the recipes.
The Illinois Sustainable Food Project is a partnership between the Department of Food Science and Human Nutrition, the Department of Crop Science’s Sustainable Student Farm, and University Housing Dining Services.
With over $1 million in funding from the U of I Student Sustainability Committee over the last four years for the project, and recent renovations to the FSHN Pilot Processing Plant, the project has allowed for new opportunities in both teaching and producing consumable food.
And big plans to expand the project’s teaching and research opportunities are ahead.
“The aspect of processing those products from produce grown at the Sustainable Student Farm for the dining halls is one-of-a-kind among peer institutions,” says Brian Jacobson, assistant director of Food and Bioprocessing Pilot Plant operations. “It’s rare to see this level of processing and production happening on a university campus.”
It all started in 2013 with tomatoes grown on the Sustainable Student Farm, when the project received its first SSC grant. “It was simple, from the perspective of food safety, which is something we were concerned with upfront. Now, we can do any tomato-based sauce,” Jacobson says.
The project was immediately successful and, by 2015, Jacobson says they were able to provide 25 percent of all the pizza sauce served on campus. Assuming the tomato harvest is good this year, the project hopes to provide 100 percent of the pizza sauce on campus.
In 2016, Jacobson said they were able to add milling and grinding equipment, everything they would need to make wheat- or corn-based flours. It was Bill Davison from U of I Extension who prompted this addition to the project. “It’s something Bill is very passionate about, and there are a ton of others who think this is a phenomenally important thing that we understand better, and there has been a large push for local grains throughout the country not just the Midwest,” he says.
Through the milling project, they are able to provide not only the flour that is used by dining services, but also a tremendous amount of data on products and recipes that can be used with the grains that are grown at the U of I, even beyond the campus. “We tie that in with the breeding program here, so we know that this variety will grow well in Illinois or this climate, and we determine what types of products it can be made into,” Jacobson says, adding that they will be using the flour to provide dining halls with a tasty pizza crust that students helped to develop.
A few other products that students are working on include orange and blue tortilla chips made from orange and blue varieties of corn being grown by crop sciences, as well as a student-developed hot sauce, using produce from the Sustainable Student Farm, that will be available in in dispensers in university dining halls this fall.
Aside from the project’s uniqueness, and the delicious products, it has served as a model of sustainable food production.
“For one, it helps the farm develop another market for their products. For FSHN, processing large quantities of food to teach our students is very expensive,” Jacobson explains. “You can’t process 2,000 pounds of tomatoes into something and explain to students how it works unless you have something to do with those 2,000 pounds of tomatoes. Otherwise you’re buying all that and just throwing it into the garbage, and it’s just not fiscally sustainable.
“You can’t teach full start-to-finish processing techniques without having a program set up for what to do with the outputs.”
Jacobson also says that before, students observed how equipment such as an industrial-sized pressure cooker worked just by watching as water was heated—just a demonstration. “Now, they have an actual process with real food and real conditions they can learn from. So it provides us as a department a really good educational piece to our students.”
The project also benefits the university’s dining services in that it helps them to meet mandates around local food procurement set forth in the Illinois Climate Action Plan. “For dining, it’s a huge benefit. The university dining team, are just some of the most outstanding people in the world, and are extremely supportive of the educational mission. They understand how important this is from a sustainability and environmental impact piece, and it’s something they want to do regardless of those other pieces that are there.
“It fits all three of us—Crop Sci, FSHN, and dining—really well,” Jacobson adds.
SSC funds have covered the costs of purchasing nearly all the processing equipment needed for these projects. The ongoing portion of the project is funded through dining, who is receiving the product from project members. “With the pizza sauce, for example, dining pays us a fee to process it, they pay the farm for the tomatoes, and those funds pay for student internships, maintenance on the equipment, small supplies, etc.,” Jacobson explains. “We intelligently bought equipment all the way through that was very flexible, so if we wanted to process something else off the farm, we wouldn’t have to purchase other equipment. The projects, after receiving the one-time capital from the SSC, become self-supporting.”
A new grant in 2017 will help the project expand to processing cold-pressed fruit and vegetable juices using produce from the U of I Multifunctional Woody Perennial Polyculture project. Eventually the hope is to offer grab-n-go juice products in university dining convenience stores
Goldenrods for the garden
URBANA, Ill. – When August arrives, our gardens start to show off their late summer beauty. Butterflies flit from plant to plant, often alighting on members of the Solidago species, commonly known as goldenrods. This native plant has gained popularity in recent years.
“Years ago, goldenrod was erroneously blamed for hay fever,” says University of Illinois Extension educator Martha Smith. “People assumed that its bright yellow blooms had to be what caused sneezing and watery eyes in late summer.”
The falsely accused goldenrods were pulled from ditches to be sprayed or burned. Now we know, Smith says, that the true culprit is the fairly unattractive ragweed, an Ambrosia species. Goldenrod pollen is sticky and requires an insect to be transmitted, while ragweed pollen is fine, dust-like, and blows in the wind – and into the passerby’s eyes and nose.
“At the same time we were attempting to eradicate the native goldenrod plant, Europeans were snatching it up and hybridizing shorter cultivars for the cut flower industry,” Smith says. “Now, we are buying them back!”
The Chicago Botanic Gardens conducted a five-year study of Solidago species to determine the best goldenrods for Midwestern gardens. The project evaluated 25 species and garden hybrids to assess ornamental traits, disease and pest resistance, and environmental adaptability. Plants were grown in typical conditions for Midwestern gardens.
The best overall rating went to Solidago rugosa ‘Fireworks.’ Tiny yellow flowers appear in September on curved threadlike panicles, creating the effect of fireworks and attracting monarch butterflies. Sturdy stems grow to 3 or 4 feet with foliage that is only mildly affected by powdery mildew.
The garden hybrids ‘Baby Sun’ and ‘Goldkind’ share many of the same qualities as ‘Fireworks’ but on a shorter plant. Neither grow taller than 3 feet, with strong stems that rarely flop. Both start to bloom in July.
‘Crown of Rays’ is a cultivar often seen in the trade. It is similar to habit size and floral character to Baby Sun and Golden Baby, but has more powdery mildew injury and some winter injury.
Solidago sphacelata ‘Golden Fleece’ is a compact goldenrod – approximately 22 inches – with heart-shaped basal leaves and airy floral displays. Late in the season, crowns begin to open, giving a lazy appearance. The plants spread in the third season. ‘Golden Fleece’ starts to bloom in August and continues into November.
Solidago flexicaulis ‘Variegata’ offers gold-mottled leaves. The study showed this variegation was strong in the spring and weakened by late August. The sulfur yellow flowers grew to 3 to 4 feet on wiry zigzagged stems. This goldenrod is rhizomatous and will spread at a modest rate.
“Goldenrods have a place in our gardens,” Smith says. “Those interested in attracting butterflies and other guests to late summer gardens will find them invaluable. Now that we have shorter cultivars, there is a goldenrod for every garden.”
New way to detect Palmer amaranth in contaminated seedlots
URBANA, Ill. – Last summer, farmers in the Midwest got an unwelcome surprise after planting native seed on Conservation Reserve Program acres. Palmer amaranth, the aggressive and hard-to-kill weed, had established in droves. As a possible solution, some states declared Palmer a noxious weed, which prohibits its sale and transport.
“I’ve had seed growers call me,” says Pat Tranel, molecular weed scientist in the crop sciences department at the University of Illinois. “Their businesses are up in the air because of this. Unless they have a way to certify their product is Palmer-free, they can’t sell it.”
The typical testing method involves growing a sample of seeds until the plants are large enough to be identified, but this is a slow and potentially unreliable process.
“It all takes a long time, and sometimes the seeds don’t germinate during the test,” Tranel says. “Alternatively, there’s a company that will test individual seeds using DNA sequencing, but they’re charging $100 per seed. It’s not cost-effective.”
Tranel and graduate student Brent Murphy developed a way around these issues. Their low-cost method can identify Palmer amaranth DNA from within a mixed sample without having to grow the plants. The assay, which uses a method known as quantitative PCR, can detect genetic variations unique to Palmer even when flooded with samples from closely related species, including waterhemp.
“Palmer, redroot pigweed, waterhemp – they all have tiny black seeds that basically look the same. We needed a way to efficiently extract DNA from pooled seed samples and, if it’s present, identify Palmer,” Tranel says.
Once Tranel and Murphy developed this assay, they worked with U of I Extension’s Plant Clinic to optimize the test for mixed seed samples. Diagnostic outreach Extension specialist Diane Plewa and Plant Clinic technician Elizabeth Phillippi began trying different methods to extract DNA from seed. The assay is very sensitive, but if DNA is not correctly extracted from a lone Palmer amaranth seed in a mixed sample, it won’t be detected.
“The trick,” Plewa says, “is to make sure every seed is ground up during the extraction process.”
The researchers were able to consistently detect a single Palmer amaranth seed when mixed with 99 waterhemp seeds, and they believe the assay could achieve even greater sensitivity with additional refinement.
The Plant Clinic has optimized a protocol for commercial testing of seed lots. “We have a test that we feel very confident in,” Plewa says. “We are offering the service now, for $50 per sample.” For more information, call 217-649-3941 or visit the Plant Clinic website.
The article, “A quantitative assay for Amaranthus palmeri identification,” is published in Pest Management Science. Authors Brent Murphy and Pat Tranel are housed in the Department of Crop Sciences at U of I, and Diane Plewa, Elizabeth Phillippi, and Suzanne Bissonnette are from U of I Extension’s Plant Clinic. The work was supported by a USDA National Institute of Food and Agriculture Hatch grant.
Bringing your garden indoors with cut flowers
URBANA, Ill. – As gardeners, many of us like to relax in the backyard, taking time to enjoy our beautiful flowers. Why not bring those beautiful bloomers indoors to enjoy? Many showy flowers, grasses, and foliage are available to interplant into your existing garden beds, allowing you to harvest throughout the seasons.
“The most important thing to consider when choosing a plant for a cut flower garden is the vase life of the flower,” says University of Illinois Extension educator Candice Hart. “Some flowers simply do not last long once cut from the plant. Daylilies, for example, have a very accurate name; the flower only lasts for a day, making it a poor choice for a cut flower garden. On the other hand, oriental lily, a perennial bulb, has a much longer vase life.”
Listed below is a selection of plant choices for a long-seasoned cut flower garden in Illinois. These annuals, perennials, bulbs, grasses, and shrubs will be easy to grow and the vase life of the flowers will be at least a week in most cases.
Annuals may be easily started from seed indoors to create transplants or may be direct-seeded right into the garden. Easy to grow examples include zinnias, strawflower, celosia, gomphrena, amaranth, cosmos, blackeyed Susan, and sunflowers.
Bulbs make great additions to an existing garden bed that needs a bit of color. Spring flowering bulbs are perennials and are planted in the fall. Summer bulbs are planted in the spring and dug up at the end of the season. Both types of bulbs can serve as beautiful cut flowers. Spring flowering bulbs like tulips, daffodils, and lily of the valley are all long-lasting cut flowers. Dahlias and gladiolus are beautiful summer bulbs that are worth the effort of digging up at the end of each season.
Stagger out your flowering times when selecting your perennials to have flowers always available for cutting. Hellebores, bleeding heart, peonies, iris, liatris, purple coneflower, eryngium, poppies, astilbe, clematis, yarrow, and sedum are all reliable options.
Foliage plants, grasses, and shrubs
These plants may not have showy flowers, but they add a unique texture to your garden arrangements. Plant lamb’s ear, dusty miller, scented geranium, hosta, Solomon’s seal, coral bells, miscanthus, northern sea oats, beautyberry, smoke bush, spirea, Japanese pieris, and ninebark in your garden to have a ready supply of foliage and textural elements to add to your vase.
“The best time to cut flowers from the garden is in the morning, before the dew has evaporated. The next-best time to cut flowers is in the early evening,” Hart says. “Be sure to place your stems into water with a floral preservative as soon as possible after cutting. Floral preservative packets can be found at your local florist. Remove any foliage from the stems that will be under water, and place your vase in a cool location, away from direct sunlight or drafts. Change your water every few days, adding a new floral preservative packet each time, to ensure a long vase life for your beautiful garden arrangement.”