Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researcher Identifies Pathogen Strain Responsible for Irish Potato Famine

19.03.2004


North Carolina State University plant pathologist Jean Beagle Ristaino shocked the scientific world when she published a paper in the journal Nature that called into question the then-prevailing theories about the strain of pathogen – and its place of origin – that caused the Irish potato famine in the 1840s.


Specimen of potato infected with Phytophthora infestans collected by John Lindley in 1846 at the Royal Botanic Garden, Dublin, Ireland.



Using DNA fingerprinting analysis of 150-year-old leaves – evidence that had not previously been studied – Ristaino ruled out the longtime prime suspect behind the famine: the Ib haplotype, or strain, of the late-blight pathogen Phytophthora infestans, which was presumed to have originated in Mexico.

Now, in a new study, Ristaino and postdoctoral student Kim May point the finger at the Ia strain of P. infestans, and trace its probable roots to the Andes Mountains in South America.


The study will be published in the April 2004 edition of Mycological Research.

The researchers used DNA sequences from mitochondrial DNA to examine 186 specimens from six different regions of the world dating from as early as 1845 to as late as 1982. The specimens included ones from late-blight epidemics in Ireland, the United States and continental Europe, and came from collections housed in England, Ireland and the United States.

About 90 percent of the specimens were confirmed to be infected with P. infestans, the paper reports. About 86 percent of the specimens – including those involved in major epidemics in Ireland and other locations around the globe – were infected with the Ia haplotype of P. infestans. The Ib haplotype – the one previously presumed to be the culprit behind the Irish potato famine and other epidemics before Ristaino’s groundbreaking 2001 study – was present only in more modern samples from Central and South America.

Moreover, the researchers found two strains – Ia and IIb – in potato specimens studied from 1950s Nicaragua. This finding further debunks the single-strain theory that prevailed before Ristaino’s 2001 Nature paper.

Ristaino’s lab is currently investigating the center of origin of P. infestans. She hypothesizes that the pathogen originated in South America and perhaps made its way to Europe and the United States via exports of potato seed on steamships. The data to support this hypothesis will be published by one of Ristaino’s graduate students, Luis Gomez, in the next year.

There are four haplotypes of P. infestans – Ia, Ib, IIa and IIb – which is a fungus-like pathogen that causes severe lesions on leaves of potato and tomato plants.

The late-blight pathogen led to the Irish potato famine, which killed or displaced millions of Irish people, and other epidemics across the world. Late blight continues to wreak havoc as a major potato and tomato killer, which makes Ristaino’s research all the more important.

“If we can understand the strains of P. infestans that are out there now and see how the pathogen has evolved over time – including how it mutates in response to fungicides or host resistance – we’ll better be able to manage the disease,” Ristaino said.

The research is funded by the National Geographic Society, the USDA National Research Initiatives Cooperative Grants Program, the North Carolina State Agricultural Research Service and NC State’s International Programs Office.

Mick Kulikowski, | NC State University
Further information:
http://www.ncsu.edu/news/press_releases/04_03/109.htm

More articles from Agricultural and Forestry Science:

nachricht Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy

nachricht New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>