Outwitting pesky parasites

Jul 15, 2007

Across the southern United States, an invisible, yet deadly parasite known as the root-knot nematode is crippling soybean crops. While plant breeders are racing to develop cultivars resistant to the root-knot nematode, they are being slowed down by current time-consuming and expensive methods of screening for resistant plants. Now, researchers believe they have found a shortcut for screening resistant soybean crops.

Researchers at the University of Georgia report the discovery of several molecular markers that will help soybean breeders to accurately screen for root-knot resistant plants at a fraction of the time and cost of current screening techniques in the July issue of The Plant Genome.

While previous studies of soybean crops helped researchers to locate genes associated with root-knot nematode resistance, University of Georgia scientists recently identified single nucleotide polymorphisms (SNPs), slight variations in the DNA, nearby genetic regions that code root-knot nematode resistance. After linking the identified SNPs to root-knot nematode resistance, scientists developed a marker assisted screening test that used SNPs to determine whether or not plants were resistant to root-knot nematode.

“The basic objective of any breeding scheme is to identify elite individuals that can pass on their desirable characteristics,” explained Bo-Keun Ha, lead author of study. While Ha says most conventional breeders rely on phenotypic evaluations of plants to select the plant with most desirable traits, this process takes time and money. For example, if a breeder wants to select plants with resistance to root-knot nematode based upon a phenotypic evaluation alone, he or she must grow a large population of plants, inoculate plants with nematode eggs, wait until the growth of the nematode and evaluate the damage before selecting the most resistant plants.

Instead of relying on the time-consuming phenotypic screening to determine whether or not the root-knot resistance genes are present in soybean crops, “marker assisted selection can inform breeders about the presence of the resistance gene in individual plants,” said Ha. Also, because marker assisted selection involves the screening of a few markers across thousands of plants Ha pointed out that the marker assisted selection is rather inexpensive and time efficient.

“Our results found SNPs linked to two root-knot nematode resistance genes and developed the resources for a relatively high throughput method of selection for the two genes,” said Ha. “The SNP assays that we have reported will empower soybean breeders to efficiently incorporate root-knot resistance genes into new productive cultivars.”

Source: Crop Science Society of America

Explore further: USDA seizes more than 1,200 illegal giant snails

add to favorites email to friend print save as pdf

Related Stories

FIXD tells car drivers via smartphone what is wrong

2 hours ago

A key source of anxiety while driving solo, when even a bothersome back-seat driver's comments would have made you listen: the "check engine" light is on but you do not feel, smell or see anything wrong. ...

Team pioneers strategy for creating new materials

3 hours ago

Making something new is never easy. Scientists constantly theorize about new materials, but when the material is manufactured it doesn't always work as expected. To create a new strategy for designing materials, ...

Shell files new plan to drill in Arctic

4 hours ago

Royal Dutch Shell has submitted a new plan for drilling in the Arctic offshore Alaska, more than one year after halting its program following several embarrassing mishaps.

Aging Africa

4 hours ago

In the September issue of GSA Today, Paul Bierman of the University of Vermont–Burlington and colleagues present a cosmogenic view of erosion, relief generation, and the age of faulting in southernmost Africa ...

Recommended for you

Team defines new biodiversity metric

4 hours ago

To understand how the repeated climatic shifts over the last 120,000 years may have influenced today's patterns of genetic diversity, a team of researchers led by City College of New York biologist Dr. Ana ...

Danish museum discovers unique gift from Charles Darwin

8 hours ago

The Natural History Museum of Denmark recently discovered a unique gift from one of the greatest-ever scientists. In 1854, Charles Darwin – father of the theory of evolution – sent a gift to his Danish ...

User comments : 0