This is the VOA Special English Agriculture Report.
now have a genetic map of the potato. The project is the work of a team from
fourteen countries, the Potato Genome Sequencing Consortium.
Potatoes are one of the world's leading food crops. But
potato breeders currently spend ten to twelve years developing new kinds. Now
they will be able to locate genes for any desired trait, improving quality,
nutritional value and disease resistance.
A genome contains information about
every position along chromosomes, the structures that hold genes. Genes direct
the making of proteins which do much of the work in building an organism,
whether a person or a potato. A potato has twelve chromosomes and about eight
hundred forty million base pairs. This is about one-fourth the size of the
The potato genome is not yet final but it shows the
order of ninety-five percent of the genes. Most potato varieties carry four
separate copies of their genes. But the researchers did much of their work with
a phureja, a kind of a potato that has only one copy. Richard Veilleux, a
professor at Virginia Tech, provided that variety of potato.
biologist Robin Buell at Michigan State University also worked on the genome.
She says it will improve understanding of other crops because potatoes are
related to tomatoes, peppers and eggplants.
In a separate development, another team reported
completing a genome of the organism responsible for late blight. That disease can
infect potatoes, tomatoes and some other plants. It causes several billion dollars
a year in agricultural losses around the world.
But late blight was also the cause of
the potato famine in Ireland in the middle of the eighteen hundreds. Potato
shortages caused at least one million deaths and a wave of Irish immigration to
The scientists say that in the short
term, studies based on the new genome may help explain why the pathogen has
been so aggressive. And in the long term, they say, knowing where different
genetic traits may be found on the map could lead to better plants. It could
also reduce the need for chemicals.
of the project was announced in the journal Nature. Researchers at Harvard
University and the Massachusetts Institute of Technology led the work.
And that's the VOA Special English Agriculture
Report, written by Jerilyn Watson. You can find all of our reports, with
transcripts and MP3s, at voaspecialenglish.com. I'm Bob Doughty.