March 28, 2008 — Soybean varieties with
improved yield, pest resistance, protein and oil quality and quantity
and other traits are among the benefits expected of a new project in
which Agricultural Research Service (ARS) scientists will create a
"library" of 50,000 DNA markers called single nucleotide polymorphisms
Geneticists David Hyten and Perry Cregan will "stock" the library as
part of their ongoing studies with SNP DNA markers at ARS’ Soybean
Genomics and Improvement Research Unit in Beltsville, Md. The United
Soybean Board (USB) is funding the $2.9 million, three-year project
from the organization’s soybean checkoff program.
The library’s completion will provide soybean researchers and
breeders with a valuable resource to use in characterizing the genetic
variation available for soybean improvement. For example, they’ll be
able to determine the position and characteristics of alleles, or
alternate forms of genes, within the oilseed crop’s 20 chromosomes.
A goal is to genotype nearly 20,000 lines, called accessions, in the
USDA soybean germplasm collection, which ARS curator and collaborator
Randall Nelson maintains on the University of Illinois campus at
Urbana-Champaign. The library’s anticipated 50,000 SNPs will help
researchers to take the next step in applying the soybean whole
genome-sequence data—released by the U.S. Department of Energy’s Joint
Genome Institute—to make soybean breeding more efficient and precise.
Of particular interest is using SNP marker technology to rapidly
identify plants that carry important traits like high-quality oil and
resistance to pests including soybean cyst nematodes.
The SNPs themselves are small changes, or variations, in the
sequence of four biochemical "letters"—A (adenine), C (cytosine), T
(thymine) and G (guanine)—that make up an organism’s DNA "alphabet."
Cregan and Hyten, together with their ARS and university colleagues,
have so far identified 43,000 SNPs in soybean and mapped the genome
locations of 15,000 of them.
ARS is the U.S. Department of Agriculture’s chief scientific
research agency. The USB is made up of 68 farmer-directors who oversee
investments of the soybean checkoff on behalf of all U.S. soybean
Source : US Department of Agriculture