Archive of Spotlight Feature Articles

Sea Grant-funded Researcher "Fingerprints" Wild Rice

By: Kathleen Schmitt Kline

As historic populations of wild rice around the Great Lakes region have shrunk, they have also become fragmented. By examining the plant’s genetic makeup, one researcher hopes to reveal critical evidence to aid restoration.

Wild rice was once so abundant in Wisconsin that it gave its name to many bodies of water throughout the state. One or more "Rice Lakes" are located in 21 counties, but today, many of them are rice lakes in name only.

Wild rice is an annual aquatic grass that can reach a height of eight feet. It matures in late summer, attracting huge flocks of waterfowl that feed on it. The rice beds themselves provide important habitat for small aquatic crustaceans and insects, the foundation of wetland food webs. Photo credit: Timothy Tynan

Every year Anthony Kern goes ricing for his own personal use on a small lake in northern Wisconsin using traditional Native American techniques. When he gathers material for his research, he travels in a kayak and only collects leaf tissue, not the wild rice seeds. He admits that sitting in a kayak surrounded by eight-foot tall wild rice plants can be very disorienting. "In some places the rice is so thick that I have to use a GPS to get out of it," he said. .
Photo credit: Anthony Kern

Since the settlement of Europeans, channelization, sedimentation, and industrialization have altered most Great Lakes coastal areas, making it difficult for wild rice (Zizania palustris) to survive. Even in areas where the habitat has improved, boat traffic, shoreline development, beavers, and carp can make it difficult for the remaining stands to persist. And Anthony Kern, a plant geneticist at Northland College in Ashland, Wis., says these outside factors aren’t the only problems facing wild rice—one problem may be found in the plant itself, buried deep in its genetic makeup.

As historic populations of wild rice have shrunk, they have also become fragmented. If these populations have become so isolated that they no longer share pollen, and therefore genes, they are likely to be subject to inbreeding. Just like in humans, inbreeding can result in problems that impair individuals and entire populations. Previous research suggests that inbred wild rice plants are smaller, weaker, and produce less seed—characteristics that could cause a dramatic decline in an already small, struggling wild rice population.

Together with Ronald Phillips at the University of Minnesota, Kern spent two years combing through the wild rice genome to identify 40 distinct regions of DNA called microsatellites, which are particular locations on a DNA strand that contain a repetitive sequence of genetic information. Kern will use these molecular markers to determine whether fragmented populations of wild rice have now become genetically distinct and are experiencing inbreeding. By noting various physical traits of the plants he samples over the next two seasons and correlating those physical measures with his molecular analyses, he will try to quantify the degree of inbreeding that is taking place and assess how it is affecting the health of the population. Kern will also compare the genetic variability in fragmented populations to that of the Bad River/Kakagon Sloughs near Ashland, the only large, pristine coastal population of wild rice remaining in the Great Lakes region.

The nutty-flavored, protein-packed grain has been an essential part of the diets of Native Americans throughout the Great Lakes region for hundreds of years. It could be stored for long periods of time and used to add substance and sustenance to soups and stews. In Wisconsin, wild rice is still harvested in the traditional Native American way, using smooth, rounded, wooden rods to gently knock the seeds from the plants into a canoe. Here, tribal members from the Bad River Band of Lake Superior Chippewa (Ojibwe) harvest wild rice on the Kakagon Sloughs near Ashland, the only large, pristine coastal population of wild rice remaining in the entire Great Lakes region.
Photo credit: Timothy Tynan

While still in the first year of the study supported by Wisconsin Sea Grant, Kern is hoping that his results will aid wild rice conservation work underway throughout the Great Lakes region. The molecular markers he developed will be available to anyone seeking to determine the genetic variability of specific wild rice populations. And for the small, remnant populations that agencies may wish to expand, understanding genetic variability is critical to selecting seed sources. The key is to provide enough variability to prevent inbreeding without introducing deleterious traits that could weaken the population.

"Some people say throw in seed from a bunch of sources and let the best genotypes win," Kern said. "That may be fine in places where wild rice has been completely wiped out or where it never existed before. But where there is a remnant population, it’s a very special, unique situation, because those remnant populations serve as reservoirs for genetic adaptations that are unique to that particular habitat. We want to conserve as much genetic diversity in the plant across its range and maintain normal, historic patterns of genetic diversity and its distribution as possible."

Wisconsin Sea Grant (www.seagrant.wisc.edu) is a statewide program of basic and applied research, education, outreach and technology transfer dedicated to the stewardship and sustainable use of the nation's Great Lakes and ocean resources.
For more information, see "Fingerprinting Wild Rice" in the Winter 2009 issue of the Aquatic Sciences Chronicle: http://aqua.wisc.edu/chronicle.

03/18/09

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