Scientists Study State Flower's Super Weed Potential
Alexander said that crop sunflowers are generally bigger, have less dormancy and have greater disease and insect resistance.
According to Alexander, a hybrid sunflower plant is a plant whose parents consist of both crop and wild sunflowers. Characteristics from the crop sunflowers are transferred to the hybrids.
Alexander began her research in the late 1990s when Dr. Allison Snow, Ohio State University, contacted her about a project. Since then, Alexander and others, including her students, such as Moody-Weis have done a range of research on sunflowers. They recently received a four-year grant from the U.S. Department of Agriculture to study sunflowers at the seedling stage.
Alexander and Moody-Weis’ work is part of an ongoing project.
“I think that this research shows that we can use basic biology to assess the risk of the escape of transgenes from crop populations, and that much work needs to be done to fully access the risk.”
According to Alexander, there are two main issues, the genetic question and the ecological question. Alexander studies the ecological aspects of sunflowers. She said that ecology of this project can be broken down into space and time. Time includes multi-year studies and the dormancy of seeds. Space encompasses local patches and populations, metapopulation and regional distributions.
Alexander said that crop sunflowers have larger seeds, which is why people like to eat them. Alexander worked with Snow, Loren Riesberg, Indiana University and Charity Cummings, former KU graduate student to study seed size, characteristics of seeds and seed predation. They found that the average size of crop seeds is 48 milligrams, the average size of wild seeds is seven milligrams, and the average size of crop-wild hybrid seeds is nine milligrams.
One aspect of super weeds that the scientists studied was the effect of hybrids on animals in the environment.
“Quail, turkey and mice like to eat seeds,” Alexander said. “Maybe hybrid seeds get eaten more often. What we wanted to know is if there is going to be a difference in predation with hybrid seeds versus wild seeds. We found that the more hybrid seeds were eaten by the critters.”
The findings of this study were published in “Ecological Applications” in 2002. Alexander was also involved in the research for and writing of an article titled “Seed Size Variation and Predation of Seeds Produced by Wild and Crop-Wild Sunflowers.” This was published in the “American Journal of Botany” in 2001.
Moody-Weis’ research for her dissertation focused on regional distributions.
“My dissertation research had three components,” Moody Weis said. “The first chapter examined the roles of seed density and soil disturbance on the formation of seed banks. The second chapter looks at how we can translate information between different spatial scales. My third chapter focuses on really large scale issues, basically the modeling of the geographic distributions of sunflowers.”
Alexander and Moody-Weis are currently working with Snow and Kristin Mercer from Ohio State University on research for the new four-year grant. Their current research focuses on sunflowers at the seedling stage. According to Alexander, they have three goals, first to study the differences between hybrid and wild seeds without competition, and second to look at the survival and growth of hybrid and wild seeds with competition.
“Do the hybrid seedlings out compete the wild seedlings?” Alexander said.
The third aspect of their current research will be a population experiment. They will sow a combination of wild and hybrid seeds at different frequencies. Much of this research and growing is done at the Kansas Ecological Reserves , owned by The University of Kansas and located 20 minutes North of Lawrence. A variety of scientific work is done at the Kansas Ecological Reserves and a portion of it, including a nature trail is open to the public.
Moody Weis said that risk of the super weed scenario becoming a major problem may be low, but that is important to be careful anyway.
“I think that we have to be very cautious in introducing transgenes into our ecosystem,” Moody-Weis said. “Once they are out in the environment, we cannot recapture them.”