February 20, 2014
US develops tool for identifying key soy genes
USDA''s Agricultural Research Service (ARS) scientists in Beltsville, Maryland have developed a new tool to search for soy genes that will make soy plants more productive and better able to resist pests and diseases.
Scientists are constantly searching for genes to breed into soy that improve on disease resistance, yields, drought tolerance and other important characteristics. The tool was developed by ARS scientists Perry Cregan, Qijian Song and Charles Quigley at the Soy Genomics and Improvement Laboratory in Beltsville. Using the new tool, scientists can collect genetic information in three days that previously took weeks to gather.
The tool, called the SoySNP50K iSelect SNP BeadChip, is a glass chip about three inches long with an etched surface that holds thousands of Deoxyribonucleic acid (DNA) markers. The markers can be used to characterise the genomes of large numbers of soy plants.
To create it, the researchers analysed and compared the DNA of six cultivated and two wild soy plants to identify single nucleotide polymorphisms (SNPs), a commonly used type of molecular marker. They compared SNPs from the eight soy plants with sequences of a well-known cultivated variety and came up with thousands of gene markers to use as signposts when comparing genes of different soy plants.
The researchers have used the chip to profile 96 wild and 96 cultivated soy varieties by comparing SNP alleles, or variant forms, at each of their 52,000 positions on the soy genome, as registered on the chip. They identified regions of the genome that played a key role in the plant''s domestication.
The researchers also used the chip to analyse the 18,484 cultivated soy accessions and 1,168 wild soy accessions in the USDA Soy Germplasm Collection at Urbana, Illinois, and submitted the data to the USDA-ARS soy genetics and genomics database so it can be accessed by breeders and geneticists.
ARS is USDA''s principal intramural scientific research agency, and this research supports the USDA priority of promoting international food security.