May 20, 2008

Scientists find short-cut to understanding corn rootworm traits

Scientists at the Agricultural Research Service have taken the first step in developing a more efficient system of identifying genetic markers in corn rootworm populations.

The discovery could increase the understanding corn rootworm traits such as their resistance to insecticides and their dispersal patterns.

The ARS, an arm of the USDA, estimates that the corn rootworm costs US producers approximately US$1 billion annually in yield losses and control measures.

The basis of the discovery involves small sections of DNA called short sequence repeats, or SSRs, of corn rootworm populations from existing databases, rather than the existing procedures that use SSRs identified from individual DNA of corn rootworms.

"It's the first step in understanding the genetic basis of certain behaviors and how much conductivity there is between populations," said Thomas Sappington, an entomologist at the ARS' Corn Insects and Crop Genetics Research Unit in Ames, Iowa.

Using already existing information culled from genetic databases also cut down on research costs and the need to apply for competitive grants. Sappington estimated it would have saved a year of research.

Researchers designed a test to determine whether genetic markers taken from existing databases were as precise in determining genetic markers as those SSRs identified from individual DNA.

The results indicate that both methods are as effective in identifying genetic markers.