“The wheat genome is the holy grail of plant genomes,’’ said Nick Talbot, a professor of biosciences at the University of Exeter who wasn’t involved in the research. “It’s going to really revolutionize how we breed it.’’
University of Liverpool scientist Neil Hall, whose team cracked the code, said the information could eventually help breeders of varieties of wheat better identify genetic variations responsible for disease resistance, drought tolerance, and yield. Although the genetic sequence remains a rough draft, and additional strains of wheat need to be analyzed for the work to be useful, Hall predicted that it wouldn’t take long for his work to affect the field.
“Hopefully the benefit of this work will come through in the next five years,’’ he said.
Strands of genetic information — DNA — are the building blocks of life, and an organism’s genetic sequence is like an instruction book spelling out which block goes where. Decoding the entire sequence, known as the genome, gives unparalleled insight into how an organism is formed, develops, and dies.
Wheat is a relative latecomer to the world of genetic sequencing. This year marks the 10th anniversary of the date the human genome was laid bare. Other crops have had their genetic codes unscrambled within the past few years — rice in 2005, corn in 2009, and soybeans earlier this year.
The reason for the delay in analyzing wheat’s genetic code, Hall said, was that the code is massive — far larger than corn or rice and five times the length of the one carried by humans.
One reason for the outsize genome is that strains such as the Chinese spring wheat analyzed by Hall’s team carry six copies of the same gene (most creatures carry two.) Another is that wheat has a tangled ancestry, tracing its descent from three different species of wild grass.
But sequencing techniques have improved dramatically over the past decade. The process used in this case is called pyrosequencing, which Hall said allowed his team to monitor a million strands of DNA at a time. He said the sequence took about a year to compile.
