Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

If GMO genes escape, how will the hybrids do?

02.11.2010
Fitness and growth of sorghum, shattercane, and its wild-crop hybrid in Nebraska

GMOs, or Genetically Modified Organisms, may raise concerns of genes escaping from crops and having unknown effects on natural, wild species. But what is the real risk that traits associated with GMOs will actually migrate to and persist in their wild relatives?

Interest in plant ecology, crop production and weed management led John Lindquist and his colleagues from the University of Nebraska and USDA-ARS to investigate how gene flow from a cultivated crop to a weedy relative would influence the ecological fitness of a cropwild hybrid offspring. They published their findings in the recent October issue of the American Journal of Botany (http://www.amjbot.org/cgi/reprint/97/10/1610).

Grain sorghum (Sorghum bicolor subsp. bicolor) is an important food and feed crop throughout the world. The reduced digestibility of sorghum seed relative to other grains makes it a less efficient resource, even though it is highly adapted to growth in semiarid environments common to Africa, India, and the Southern and Western Great Plains of the United States. There has been considerable interest in modifying the quality traits of grain sorghum using GMO technology to enhance its nutritional value to both humans and animals raised for human consumption.

A major challenge to sorghum producers is the limited number of products available to control weeds within the crop—too many of the common products cause crop damage. To address this challenge, one of the major U.S. seed companies is developing herbicide-resistant grain sorghum using traditional breeding (non-GMO) strategies and plans to deploy them in the United States within the next 5 years.

There is inherent risk in deploying grain sorghum containing novel genes because several related species (e.g., johnsongrass, shattercane) are capable of interbreeding with grain sorghum.

Lindquist and his colleagues focused their research on gene flow between sorghum and its closely related, wild, weedy relative, shattercane (Sorghum bicolor subsp. drummondii). Lack of information on the potential gene flow from grain sorghum to shattercane is an important problem because it limits our fundamental understanding of gene transfer and potential hybridization between grain sorghum and shattercane. Their goal was to obtain baseline data using non-GMO sorghum and shattercane that would improve our ability to assess the potential risks of introducing novel genes in grain sorghum into U.S. agroecosystems.

Variation in alleles contributes to the ability of a population to adapt to a variable environment. Yet, this variation is often controlled in cultivated crops for ease of production—for example, with sorghum, all seeds germinate at roughly the same time, plants grow to a uniform height, and seeds ripen at the same time. In contrast, shattercane has seeds with variable states of dormancy, plants that grow taller than sorghum, and seeds that disperse via a shattering mechanism, ensuring dispersal before the sorghum crop is harvested. By crossing shattercane with cultivated sorghum, the authors compared how the crop-wild hybrid performed relative to its crop and wild parents in a number of traits that may be important to its ecological fitness.

By experimentally manipulating temperature conditions, the authors found different germination patterns for the three types of seeds. Although the crop-wild hybrid responded to low temperatures similarly to its wild shattercane parent—both in terms of percentage of seeds that germinated and by staying dormant and delaying germination—it responded to high temperatures similarly to its cultivated sorghum parent; non-germinated seeds of both sorghum and the hybrid died. This may be linked to their seed structures. Shattercane seeds are completely enclosed by glumes, whereas those of sorghum are only partially covered, a factor that makes them much easier to mill but does not protect them well from environmental extremes. The glumes on the hybrids are more similar to sorghum, so it is possible that despite their ability to be dormant, they may not survive well in extreme environmental conditions.

When the authors compared growth factors under natural field conditions, they found that the hybrid grew taller than either of its parent types, had greater leaf area than the shattercane but less than sorghum, and leaf emergence was earlier than in the shattercane. The authors speculate that if the three types were grown in mixture in the field, the hybrid would likely be able to capture more light and thus be more competitive than the two parent types. However, the hybrid produced fewer seeds than either sorghum or shattercane (although they were similar to shattercane at one site).

"Genes from grain sorghum, including a transgene or a traditionally bred specialty trait such as the herbicide resistance traits in sorghum, could be successfully transferred to a weedy shattercane population," Lindquist concludes. Indeed, in this case the relative fitness of the hybrid may be equivalent to that of the wild parent.

However, further research is needed. "It is imperative to know the rate of outcrossing from sorghum to shattercane," Lindquist emphasizes. "In other words, what proportion of seed on a shattercane plant will be pollinated by a nearby grain sorghum population, and how far can that pollen go?"

"Next, we want to be able to predict the overall likelihood that a gene from grain sorghum will enter the weedy shattercane population."

CITATION: Lilyrani Sahoo, Jared J. Schmidt, Jeffrey F. Pedersen, Donald J. Lee, and John L. Lindquist (2010). Growth and fitness components of wild x cultivated Sorghum bicolor (Poaceae) hybrids in Nebraska. American Journal of Botany 97(10): 1610-1617. DOI: 10.3732/ajb.0900170

The full article in the link mentioned is available for no charge for 30 days following the date of this summary at http://www.amjbot.org/cgi/reprint/97/10/1610. After this date, reporters may contact Richard Hund at ajb@botany.org for a copy of the article.

The Botanical Society of America (www.botany.org) is a non-profit membership society with a mission to promote botany, the field of basic science dealing with the study and inquiry into the form, function, development, diversity, reproduction, evolution, and uses of plants and their interactions within the biosphere. It has published the American Journal of Botany (www.amjbot.org) for nearly 100 years. In 2009, the Special Libraries Association named the American Journal of Botany one of the Top 10 Most Influential Journals of the Century in the field of Biology and Medicine.

For further information, please contact the AJB staff at ajb@botany.org.

Richard Hund | EurekAlert!
Further information:
http://www.botany.org

More articles from Life Sciences:

nachricht During HIV infection, antibody can block B cells from fighting pathogens
14.08.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht First study on physical properties of giant cancer cells may inform new treatments
14.08.2018 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>