Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rapid evolution within single crop-growing season increases insect pest numbers

16.08.2011
UC Riverside research could help prevent crop loss, pest outbreaks

New research by scientists at the University of California, Riverside shows that evolution – genetic changes in populations over time – can occur so rapidly in organisms that its impact on population numbers and other aspects of biology can be seen within just a few generations.


This image shows a female Green Peach Aphid clone with a line of her clonal daughters soon after live birth (older clones are bigger). Credit: M. Turcotte.

The research, published online Aug. 9 in Ecology Letters, the highest ranked journal in the field of ecology, can improve scientists' ability to predict the growth and spread of endangered species, invasive species, and disease epidemics.

Working on aphids, considered the world's most important crop pest, the researchers experimentally tested the impact of rapid evolution on wild populations within a single crop-growing season. To accomplish this, the researchers set up an experiment that prevented evolution by natural selection from occurring in some aphids while allowing it in others. They then compared the rate at which the non-evolving and evolving populations grew.

Each fall, aphids undergo one generation of sexual reproduction. The following spring, they begin multiple generations of asexual reproduction. During this period multiple clonal lineages compete, leading to changes in gene frequencies and mean trait values in the population in the process.

In their field experiment, the researchers compared replicated aphid populations that were non-evolving (single clone, thus genetically identical) to aphid populations that were potentially evolving (two clones genetically different from each other and with dissimilar growth rates).

As the populations grew, the researchers tested whether the mixed populations evolved. Counting aphids repeatedly, they found that clones rapidly changed in frequency, within 30 days or 4-5 aphid generations. They then tested the impact of this evolutionary change on the ecology of the aphids. They found that evolving populations grew in number up to 42 percent faster than non-evolving populations.

"This shows that even without human interference natural selection acting on aphid populations causes rapid evolution," said Martin M. Turcotte, who led the research as a graduate student in ecology, evolution and organismal biology at UC Riverside. "Even stronger effects might be expected when pesticides are in use. For decades, evolution was deemed too slow and, hence, it was not considered when studying population growth – an oversight that needs to be corrected. Ignoring this evolution, as is not currently uncommon, can lead to predictions that greatly underestimate pest densities and outbreaks."

Rapid evolution could have important untested impacts in many other applied areas. For example, rapid evolution is important in fisheries where intense fishing causes fish to evolve traits that let them escape fishing nets. Antibiotic resistance and increased virulence in pathogens are examples where rapid evolution impacts human health.

The study was conducted at the University of California Motte Rimrock Reserve where the researchers collected multiple clonal lineages from a wild aphid population feeding on mustard plants. They identified clones and characterized their intrinsic per capita growth rates in a greenhouse at UCR.

Turcotte graduated with a doctoral degree in biology from UCR this year. Currently a postdoctoral scholar at the University of Toronto at Mississauga, Canada, he uses experimental evolution to study fundamental questions about the ecology and evolution of plant-herbivore interactions.

He was joined in the research by his co-advisors at UCR: David N. Reznick, a professor of biology, and J. Daniel Hare, a professor of entomology. A few UCR biology undergraduate students also assisted the research team.

Turcotte was funded by grants from the Natural Sciences and Engineering Research Council of Canada; Fonds de Recherche du Québec and the University of California Natural Reserve System. Grants from the U.S. National Science Foundation supported Reznick and Hare in the study.

The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 20,500 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion.

A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

More articles from Agricultural and Forestry Science:

nachricht Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli
26.04.2017 | University of the Basque Country

nachricht New data unearths pesticide peril in beehives
21.04.2017 | Cornell University

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

How Plants Form Their Sugar Transport Routes

28.04.2017 | Life Sciences

Protein 'spy' gains new abilities

28.04.2017 | Life Sciences

Researchers unravel the social network of immune cells

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>