Ug99 is a lineage of wheat
stem rust
Stem rust, also known as cereal rust, black rust, red rust or red dust, is caused by the fungus ''Puccinia graminis'', which causes significant disease in cereal crops. Crop species that are affected by the disease include bread wheat, durum wh ...
(''Puccinia graminis'' f. sp. ''tritici''), which is present in
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologica ...
fields in several countries in
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
and the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
and is predicted to spread rapidly through these regions and possibly further afield, potentially causing a wheat production disaster that would affect
food security
Food security speaks to the availability of food in a country (or geography) and the ability of individuals within that country (geography) to access, afford, and source adequate foodstuffs. According to the United Nations' Committee on World F ...
worldwide.
In 2005 the noted
green revolution
The Green Revolution, also known as the Third Agricultural Revolution, was a period of technology transfer initiatives that saw greatly increased crop yields and agricultural production. These changes in agriculture began in developed countrie ...
pioneer
Norman Borlaug
Norman Ernest Borlaug (; March 25, 1914September 12, 2009) was an American agronomist who led initiatives worldwide that contributed to the extensive increases in agricultural production termed the Green Revolution. Borlaug was awarded multiple ...
brought great attention to the problem, and most subsequent efforts can be traced to his advocacy.
It can cause up to 100% crop losses and is
virulent against many
resistance genes which have previously protected wheat against stem rust.
Although Ug99-
resistant varieties of wheat do exist,
a screen of 200,000 wheat varieties used in 22 African and Asian countries found that only 5-10% of the area of wheat grown in these countries consisted of varieties with adequate resistance.
The original
race of Ug99, which is designated as 'TTKSK' under the North American nomenclature system, was first detected in
Uganda
}), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...
in 1998
[
] and first characterised in 1999
(hence the name Ug99) and has since been detected in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
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, capital = Nairobi
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, largest_city = Nairobi
...
,
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...
,
Eritrea
Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...
,
Sudan
Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic ...
,
Yemen
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and s ...
,
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Tu ...
,
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands an ...
,
Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Mal ...
,
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Moz ...
,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
,
and
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medite ...
. There are now 15 known
races of Ug99.
They are all closely related and are believed to have
evolved
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...
from a common ancestor, but differ in their
virulence
Virulence is a pathogen's or microorganism's ability to cause damage to a host.
In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to ca ...
/avirulence profiles and the countries in which they have been detected.
Genetics
Ug99 is the product of a type of somatic nuclear exchange event which has not been observed in other stem rust races.
[
] During this event and thereafter the nuclei have not experienced
recombination.
Gene resistance
Ug99 and its variants differ from other strains of the Black Stem Rust (BSR) pathogen due to their ability to overcome
resistance genes in wheat that have been durable against the BSR pathogen for decades.
These resistant ''Sr'' genes, of which 50 are known, give wheat different resistances to stem rust.
The virulence in Uganda was virulent against ''Sr31'' and is specific to Ug99.
The massive losses of wheat that have occurred have been devastating, but in recent years the wheat rust epidemic has been effectively controlled through selection and breeding for additional ''Sr'' genes.
United States Department of Agriculture (
USDA
The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
) researchers are testing genes to determine their Ug99 resistance, which will ultimately aid in the development of wheat varieties that will be able to fight off the rust. Resistance has been identified in a small number of spring wheat land races from
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the C ...
- 23 out of 250 races with
adult plant resistance, 27 out of 23,976 SNPs conveying APR, and only 9 races having
seedling resistance.
[
] This resistance was present prior to Ug99 pathogen challenge being present in NA to drive selection.
In addition to the research being conducted by the USDA, The United Kingdom’s
Department for International Development
, type = Department
, logo = DfID.svg
, logo_width = 180px
, logo_caption =
, picture = File:Admiralty Screen (411824276).jpg
, picture_width = 180px
, picture_caption = Department for International Development (London office) (far right ...
(DFID), along with
Bill & Melinda Gates Foundation
The Bill & Melinda Gates Foundation (BMGF), a merging of the William H. Gates Foundation and the Gates Learning Foundation, is an American private foundation founded by Bill Gates and Melinda French Gates. Based in Seattle, Washington, it was ...
, announced in February 2011 that they will be granting $40 million to a global project led by
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teac ...
to combat virulent strains of Ug99.
The five-year grant to the Durable Rust Resistance in Wheat (DRRW) project supported attempts to identify new resistance genes as well as reproduce and distribute rust resistant wheat seeds to farmers.
There has been a continuous process of development of new resistant cultivars and failure of those cultivars. This demonstrates the need for continuous improvement.
[
]
modern
molecular
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...
and
molecular genetics
Molecular genetics is a sub-field of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the ...
techniques are identifying
quantitative trait loci (QTLs), particular cellular structures, and individual
R gene
Resistance genes (R-Genes) are genes in plant genomes that convey plant disease resistance against pathogens by producing R proteins. The main class of R-genes consist of a nucleotide binding domain (NB) and a leucine rich repeat (LRR) dom ...
s more efficiently than ever before.
These will be needed given the continuing severe, worldwide threat Ug99 poses.
Races
There are 15
races of Ug99, which (under the North American nomenclature system) have the designations TTKSK, TTKSF, TTKST, TTTSK, TTKSP, PTKSK, PTKST, TTKSF+,
TTKTT, TTKTK, TTHSK, PTKTK, TTHST, TTKTT+, and TTHTT.
They are all closely related and are believed to have
evolved
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...
from a common ancestor.
TTKSK
Also known as PTKS.
The first Ug99 race to be characterised.
Like most Ug99 races, and unlike other stem rust varieties, it is virulent against the ''Sr'' gene ''Sr31'';
[
}
] also virulent against ''Sr38''.
Avirulent against ''Sr24''.
It was found in
Uganda
}), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...
in ,
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
in ,
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...
in ,
Sudan
Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic ...
and
Yemen
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and s ...
in ,
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Tu ...
in ,
and
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands an ...
in ,
Eritrea
Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...
in ,
and
Rwanda
Rwanda (; rw, u Rwanda ), officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of Central Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equat ...
and
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medite ...
in .
TTKSF
First detected in South Africa in ,
Zimbabwe ,
and Uganda in .
TTKST
Discovered in
Kenya
)
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, map_caption =
, image_map2 =
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, largest_city = Nairobi
...
in
was the first Ug99 race found to be virulent against ''Sr'' gene ''Sr24''.
TTKST is now the predominant stem rust race in Kenya.
TTTSK
First detected in Kenya in ,
Tanzania in ,
Ethiopia in ,
Uganda in ,
and Rwanda in .
TTKSP
First detected in South Africa in .
PTKSK
First detected in Ethiopia in ,
Kenya in ,
Yemen in ,
and South Africa in .
PTKST
First detected in Ethiopia in ,
Kenya in ,
South Africa in ,
Eritrea and Mozambique and Zimbabwe in .
TTKSF+
First detected in both South Africa and Zimbabwe in .
Virulent against ''
Sr9h''.
[ .][ .]
TTKTT
First detected in Kenya in .
Also detected in
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to the north, Iran to the east, the Persian Gulf and ...
in 2019, the first such detection in the country.
TTKTK
First detected in Kenya,
[
] Rwanda,
Uganda,
Eritrea,
and Egypt
in .
TTHSK
First detected in Kenya in .
Differs from the original (
TTKSK) by avirulence against ''Sr30''.
Similar to
TTHST.
PTKTK
First detected in Kenya in .
Differs from
PTKSK by virulence against ''SrTmp''.
Differs from
TTKTK by avirulence against ''Sr21''.
TTHST
First detected in Kenya in .
TTKTT+
First detected in Kenya in .
Virulent to ''
Sr31'', ''
Sr24'', ''
SrTmp'', and ''
Sr8155B1''.
TTHTT
First detected in Kenya in .
Virulent to ''
Sr31'', ''
Sr24'', and ''
SrTmp'', avirulent to ''
Sr30''.
Timeline
1993
* There is some evidence that race
TTKSK may have been present in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
.
1998
* Severe stem rust infections observed in
Uganda
}), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...
. Ug99 identified, characterised as having virulence on ''Sr31'' and named.
2000
*
TTKSF detected in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
.
2001
* TTKSK detected in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
.
2003
* TTKSK detected in
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...
.
2006
* TTKSK detected in
Sudan
Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic ...
and
Yemen
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and s ...
.
*
TTKST, a new variant of Ug99 with virulence to ''Sr24'', detected in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
.
2007
*
TTTSK detected in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
.
*
TTKSP detected in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
.
*
PTKSK detected in
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...
.
*
PTKST detected in
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...
.
2008
*
FAO
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
announced the presence of Ug99 in
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Tu ...
.
[
]
*
PTKST detected in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
.
* Present in Yemen.
2009
*
TTKSK detected in
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands an ...
.
*
TTKST detected in Tanzania.
*
TTTSK detected in Tanzania.
*
TTKSF detected in
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Moz ...
.
*
PTKSK detected in
Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
.
* PTKST detected in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
.
2010
*
TTKST detected in
Eritrea
Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...
.
* PTKST detected in
Eritrea
Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...
.
* PTKST detected in
Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Mal ...
.
* PTKST detected in
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Moz ...
.
*
TTKSF+ detected in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
.
* TTKSF+ detected in
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Moz ...
.
2013
*
TTHST confirmed in Kenya
2014
*
TTKTK confirmed in
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medite ...
,
[
] Kenya, Eritrea,
Rwanda
Rwanda (; rw, u Rwanda ), officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of Central Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equat ...
, and Uganda.
*
TTHSK confirmed in Kenya
[
]
*
PTKTK confirmed in Kenya
*
TTKTT confirmed in Kenya.
*
TTKST detected in Egypt.
*
TTKSK detected in Egypt.
2017
* PTKSK confirmed in South Africa.
2019
* TTKTT detected in Iraq.
*
TTKTT+ confirmed in Kenya.
2020
*
TTHTT confirmed in Kenya.
Geographic spread
China
Although Ug99 has not yet reached
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
,
other stem rust races already have,
and an effort is under way to marry resistance against present races with future needs for resistance against Ug99 whenever it arrives.
Lebanon
Although ''Sr5'', ''Sr21'', ''Sr9e'', ''Sr7b'', ''Sr11'', ''Sr6'', ''Sr8a'', ''Sr9g'', ''Sr9b'', ''Sr30'', ''Sr17'', ''Sr9a'', ''Sr9d'', ''Sr10'', ''SrTmp'', ''Sr38'', and ''SrMcN'' are no longer effective in
Lebanon
Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus li ...
, ''Sr11'', ''Sr24'', and ''Sr31'' still are which is diagnostic for the absence of Ug99 from Lebanon.
Iraq
Detected in
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to the north, Iran to the east, the Persian Gulf and ...
in 2019.
South Asia
it was the US
Director of National Intelligence
The director of national intelligence (DNI) is a senior, cabinet-level United States government official, required by the Intelligence Reform and Terrorism Prevention Act of 2004 to serve as executive head of the United States Intelligence Comm ...
's assessment that Ug99 would arrive in
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka. ...
soon, in the following few years. This was expected to cause worldwide supply disruptions because, although productivity was growing in
Eastern Europe
Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russia, wh ...
and could theoretically fill that gap, governments worldwide had shown a readiness to forbid exports.
However South Asia remains unaffected.
See also
*
Stem rust
Stem rust, also known as cereal rust, black rust, red rust or red dust, is caused by the fungus ''Puccinia graminis'', which causes significant disease in cereal crops. Crop species that are affected by the disease include bread wheat, durum wh ...
*
Rust (fungus)
Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales (previously known as Uredinales).
An estimated 168 rust genera and approximately 7,000 species, more than half of which belong to the genus '' Puccinia'', are currently ...
References
External links
Ug99 stem rust on wheat cropsBorlaug Global Rust InitiativeFAO
{{Taxonbar, from= Q7877558
Wheat diseases
Puccinia
Fungal plant pathogens and diseases