Featured Research

from universities, journals, and other organizations

Wheat resistance genes failing, new approach needed to stop flies

Date:
January 30, 2011
Source:
Purdue University
Summary:
Many of the genes that allow wheat to ward off Hessian flies are no longer effective in the southeastern United States, and care should be taken to ensure that resistance genes that so far haven't been utilized in commercial wheat lines are used prudently, according to scientists.

Wheat with resistance genes (left) shows little damage from Hessian flies, while a non-resistant variety (right) has been largely destroyed.
Credit: Photo courtesy of Dr. Michael Boyd, University of Missouri

Many of the genes that allow wheat to ward off Hessian flies are no longer effective in the southeastern United States, and care should be taken to ensure that resistance genes that so far haven't been utilized in commercial wheat lines are used prudently, according to U.S. Department of Agriculture and Purdue University scientists.

An analysis of wheat lines carrying resistance genes from dozens of locations throughout the Southeast showed that some give little or no resistance to the Hessian fly, a major pest of wheat that can cause millions of dollars in damage to wheat crops each year. Others, even those considered the most effective, are allowing wheat to become susceptible to the fly larvae, which feed on and kill the plants.

Wheat resistance genes recognize avirulent Hessian flies and activate a defense response that kills the fly larvae attacking the plant. However, this leads to strains of the fly that can overcome resistant wheat, much like insects becoming resistant to pesticides.

"The number of genes available to protect wheat is limited. There really aren't that many," said Richard Shukle, a research scientist with the USDA Agricultural Research Service Crop Production and Pest Control Research Unit and Purdue adjunct associate professor of entomology. "In the Southeast, having multiple generations of Hessian fly each year enhances the ability of these flies to overcome wheat's resistance."

Sue Cambron, a USDA Agricultural Research Service research support scientist, received Hessian flies from 20 locations in Alabama, Georgia, North Carolina, South Carolina and Louisiana and used them to infest 21 varieties of wheat that each contained different resistance genes, most of which have been deployed in commercial wheat, and a few that haven't yet. While the study did not include all of the 33 named resistance genes, it did show that only five of the 21 genes evaluated would provide effective resistance to flies in the Southeast, and none was effective in all the Southeast locations.

"Even some of the newer genes that haven't been deployed in cultivars weren't too effective," Cambron said.

That's because flies have likely interacted with, and adapted to, those genes already, said Brandi Schemerhorn, a USDA-ARS entomologist and Purdue assistant professor of entomology. She said it's possible that some of the genes were introduced to flies unintentionally in plots where wheat cultivars with those genes were being tested for suitability to Southeast climates. The resistance genes also could have come from other plants, such as rye, and the flies may already have started to overcome those genes.

Schemerhorn said she suspects a certain number of flies in any population have the ability to overcome any wheat resistance gene, which defends against the flies' ability to feed on the plant and starves the insect larvae. When a resistance gene kills off some of the flies, the survivors breed and eventually establish a population that renders the gene ineffective.

"We're creating a system in which the fly is becoming more virulent," Schemerhorn said. "What we have to do is slow down that adaptation or virulence."

Shukle and Schemerhorn suggest stacking genes in a wheat cultivar. There are only a few genes that haven't been deployed, and they believe combining two of those would be the best option.

"With a small number of identified resistance genes, we can't afford to release wheat lines with only one resistance gene," Shukle said. "If you deploy two different resistance genes, it's unlikely that a population of flies could overcome both of them."

Schemerhorn is working to combine two of the unreleased genes for testing with Hessian fly populations.

The USDA funded the research. Shukle, Schemerhorn and Cambron collaborated with David Buntin, a University of Georgia professor of entomology; Randy Weisz, a North Carolina State associate professor of crop science and small grains specialist; Kathy Flanders, an Auburn University associate professor of entomology; and Jeff Holland, a Purdue associate professor of entomology. Their findings were published in the Journal of Economic Entomology.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sue E. Cambron, G. David Buntin, Randy Weisz, Jeffery D. Holland, Kathy L. Flanders, Brandon J. Schemerhorn, Richard H. Shukle. Virulence in Hessian Fly (Diptera: Cecidomyiidae) Field Collections from the Southeastern United States to 21 Resistance Genes in Wheat. Journal of Economic Entomology, 2010; 103 (6): 2229 DOI: 10.1603/EC10219

Cite This Page:

Purdue University. "Wheat resistance genes failing, new approach needed to stop flies." ScienceDaily. ScienceDaily, 30 January 2011. <www.sciencedaily.com/releases/2011/01/110124162714.htm>.
Purdue University. (2011, January 30). Wheat resistance genes failing, new approach needed to stop flies. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2011/01/110124162714.htm
Purdue University. "Wheat resistance genes failing, new approach needed to stop flies." ScienceDaily. www.sciencedaily.com/releases/2011/01/110124162714.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins