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 Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>