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Alexandria, Egypt
April 10, 2008
Scientists say that wild species
of barley can help improve cultivated barley as the wild species
are a treasure trove of useful genes.
Prof Brian Steffenson, Professor and Lieberman-Okinow Endowed
Chair of Cereal Disease Resistance at the University of
Minnesota, says that incorporating some of the genes from the
wild varieties into the domesticated barley could increase the
range of environments in which the crop can be cultivated.
"Wild species are a treasure trove of useful genes for improving
cultivated crop," said Prof Steffenson, who is here attending
the 10th International Barley Genetics Symposium, organized by
the International Center for
Agricultural Research in the Dry Areas (ICARDA) and
Bibilotheca Alexandrina.
"Cultivated barley came from wild varieties. When barely was
first domesticated some 10,000 years ago the farmers chose a
variety in which seeds were non shattering type so that
harvesting was easy. So the genetic diversity narrowed down
leading to dramatic loss of it," he pointed out.
Prof Steffenson is working on evaluating traits in wild
varieties collected from nature and gene banks to look for
diversity that has been left behind since first domestication.
Genebanks like that of ICARDA are extremely important to have
because they preserve the biodiversity and germplasm of
varieties whose habitat has now been destroyed, he said
"Cultivated barely is extremely vulnerable to some diseases and
epidemics of pathogens and pests," Prof Steffenson said. "Some
of the wild barley varieties when characterized have been found
resistant to Ug99. The Ug99 race of the stem rust has not
arrived in America but when it does, it can be devastating."
Agriculture scientists are endeavoring to stop the spread of the
devastating fungus, which has now been found in Iran.
Historically, sporadic epidemics of stem rust, also known as
black rust, have plagued wheat production. An outbreak of the
disease in North America in the 1950s destroyed up to 40% of the
spring wheat crop. The fungus also infects barley.
Stem rust is once again on the move. In 1999, scientists
discovered a new strain of the fungus in Uganda, now known as
Ug99 that has defeated the resistance in varieties that were
resistant to stem rust in the past. Over the past few years,
Ug99 has infected crops in North and East African countries and
in early 2006 it was found in Yemen.
Prof Steffension said about 30 varieties of wild barley have
been identified as having resistance to stem rust, including the
Ug99 strain, and all are from ICARDA.
Also, some of the accessions of wild barley collection from
ICARDA planted in Minnesota have survived extremely cold
temperatures, which at times goes down to –35 degrees. "It means
that we can put a new gene that can extend the range of
environments in which barley can be grown as a winter crop,"
Prof Steffenson said. |
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