170 years after the famine, the late blight of potatoes remains

Dundee, Scotland, 1861

Despite the tools available to combat and control plant disease, the pathogen which caused the Irish famine continues to destroy potato crops worldwide


The famine wasn’t that long ago. I can trace my family back to Peter Lettice and his wife Mary Lowrie who left Ireland in the early 1840s, in their case for Dundee, Scotland, to avoid starvation. Many people can do the same. Knowing their names means that the headline figures that get used in connection with the famine - one million dead and one million emigrated - become very personal. Those figures get used whenever anybody talks about the famine, but they make the whole thing anonymous in a way. It's something that happened to other people and their families.

The massive global changes brought about by the famine are still evident in the large number of people claiming Irish heritage in North America, Australia and elsewhere. At home, the population of the island of Ireland (approximately 6.5 million in 2016) has only now returned to pre-famine levels.
Historians can rightly point to many contributing factors and causes for the famine. Political, social and economic issues all played a role, but the cause of the crop losses at the heart of the Irish potato famine ultimately was Phytophthora infestans. This pathogen comes from a group of organisms called oomycetes and can no longer be correctly called a fungus. In fact, it’s more closely related to the brown algae.

The ‘father’ of plant pathology, Anton de Bary, was the first to demonstrate experimentally that the pathogen caused the disease we now know as late blight and de Bary coined the name Phytophthora, meaning "plant-destroyer". English botanist Rev. Miles Berkeley had first observed that late blight was "the consequence of the presence of the mould, and not the mould of the decay" 15 years earlier (Journal of the Horticultural Society of London, 1846).

Phytophthora is an appropriate moniker. Symptoms of the disease include blackish lesions on the leaves and purple-brown lesions on the surface of the tubers themselves. When the disease is advanced, the tubers are rotten inside and there is a distinctive odour which must have struck fear into the heart of poor subsistence farmers all over the country during the famine.

As any potato grower will tell you, late blight of potatoes has not gone away. It remains the most economically destructive of all potato diseases worldwide. Typically, commercial potato growers in Ireland use between 15 and 20 applications of fungicide to control the pathogen every year and there are no commercially-viable resistant varieties available. 170 years after the famine, our potato crop is still as vulnerable as ever to destruction caused by Phytophthora. The difference now is the availability of chemical control options to keep the worst of the losses at bay.

Globally, many crops are vulnerable to diseases that have the potential to cause devastating losses. For example, rice blast fungus (Magnaporthe oryzae) is the most destructive disease of rice, a staple foodstuff that feeds half the world’s population. Diseases of cereals like Puccinia and Fusarium are a threat that require constant vigilance and we are regularly reminded that the much-loved and economically important Cavendish variety of banana (that’s the banana you had for lunch) is on the brink of extinction due to Panama disease caused by Fusarium oxysporum.

A major problem is our over-reliance on a small number of crops for much of the world’s food supply. Just 15 crop plants account for 90 percent of the world’s food with maize, wheat and rice accounting for over 50 percent of the world’s caloric intake (UN FAO). If even one of the top ten crops were to fail, the consequences could be catastrophic, especially for developing countries.
Increasingly though, we are running to stand still with a lot of the major diseases. Much like the Red Queen in Lewis Carroll’s Through the Looking-Glass, keeping one step ahead of emerging and evolving plant pathogens "takes all the running you can do, to keep in the same place".

In this context, it’s more important than ever that we are using all of the tools available to us to combat and control plant disease. That means an integrated approach to pathogen and pest management where one tool such as chemical control is not over-used. Such reliance on one control method runs the risk of forcing the pathogen to evolve to overcome the control measure, rendering it useless.

One of the tools that will certainly be in that toolbox is the development of resistant varieties. However, in the case of late blight, we’ve yet to breed a commercially-viable, fully blight-resistant potato. That’s not to say it’s impossible: Sarpo Mira, Sarpo Axona and Blue Danube are all potato varieties that are very resistant to late blight but they have not been commercially successful outside of the organic market.

Luckily, help is at hand in the form of modern plant biotechnology which has the capacity to quickly develop blight resistant potato varieties as well as resistant crops to various other diseases) A major problem with conventional potato breeding is the difficulty in crossing domesticated varieties with their disease-resistant wild relatives. Genetic transformation has overcome that problem by transferring a potato gene for resistance from wild to cultivated varieties. Such varieties were grown successfully in Ireland in recent years.

Gene-editing technology will allow even more precise changes to be made to plant genomes with the goal of introducing resistance for a host of important crop diseases. Whatever our personal views on such technologies, there is no doubt they will be an integral part of maintaining global food security and preventing future famines.

Recently, Ireland was named the most food-secure nation in the world. That’s an amazing turnaround, even if it has taken 170 years. In light of our remarkably journey from famine to world leaders in food security, surely there is a moral imperative on us to support other countries to boost their food security - and to advance the science that will prevent similar famines from happening to other countries in the years to come?

The National Famine Commemoration 2018 takes place at University College Cork on Saturday May 12th. The International Association for Plant Biotechnology congress 2018 (IAPB2018) takes place in Dublin in August

This article first appeared on RTE Brainstorm.

Famine and food

The ongoing debate regarding the efficacy of genetically modified (GM) crops to increase global food security goes on, while a recent study of US consumers indicates that opinions on genetically modifies crops are not swayed by specific arguments about plant disease and famine.

At least one million people died and a further one million were forced to emigrate during the Irish potato famine of 1845-1852. Those figures are so often repeated in undergraduate plant pathology classrooms that they lose their shock value. Those years seem so distantly removed from our lives in the 21st century that we occasionally fail to recall that it happened just a handful of generations ago. The famine had such a profound impact on the social, geographic and economic landscape of Ireland that the country still bears the scars. For instance, the population of the Republic of Ireland, as measured by the 2011 census, stands at 4.6 million compared to a pre-famine population of 6.5 million in 1841. Meanwhile, there are 39.6 million Americans who claim Irish ancestry, due in part to massive emigration to the US during and immediately after the famine.

In a recently published study, American consumers were asked their opinion of GM. Half of the sample group were first asked to read a short vignette describing the causal agent of the potato famine, the fungal-like potato disease late blight. The second half of the sample was asked to read a similar vignette, though not mentioning late blight and the Irish famine specifically.

For example, the late blight-specific vignette included:
"Late blight was a key cause of the Irish Potato Famine of the 1850s that led to the starvation of millions of people in Ireland and forced many Irish to leave the country. Late blight has re-emerged in recent years as a substantial threat to crops across the United States and around the world."

Ultimately, even when the question was contextualised in relation to late blight and famine, there was no significant difference in public views about the perceived risks, benefits or fairness of GM crops. This is an interesting finding; given calls in Europe and elsewhere to increase the cultivation of GM crops, particularly in traditionally GM-sceptical nations such as the UK.
This year, for example, the Council for Science and Technology in the UK, scientific advisors to the government, called for the EU to end its “dysfunctional” regulations on GM crop cultivation saying that if the country didn’t embrace GM “the risk is people going unfed”.

Even in Ireland, where one might expect the memory of the famine to linger long with consumers, limited trials of late blight resistant potato plants in recent years have met with some resistance. These EU-funded trials, conducted by Ireland’s agricultural development agency were described as “economic suicide” by opponents who called GM an “unwanted technology”. The scientists conducting the trials, which began in 2012, were keen to stress the impartial nature of the study and that it was not about “testing the commercial viability of GM potatoes” and was specifically concerned with their environmental impact.

In fact, there is a myriad of reasons why some consumers reject GM technologies in foodstuffs. Not all of them, of course, are supported by any real science, but that doesn’t negate the fact that they are real obstacles to overcome for those who would promote a sustainable food-production system which incorporates all aspects of biotechnology, including genetic modification of crop plants. What is clear now is that simply using the approach of emphasising the crop protection benefits of GM is not enough. Consumers are, rightly or wrongly, also worried about the environmental impact of such crops and no amount of appealing to their memory of past catastrophic crop failures will appease them.

One might argue that the passing of time between the Irish potato famine and the current advances in plant biotechnology can account for the lack of relevance and impact on consumer opinion. Perhaps, informing consumers about more recent plant disease outbreaks would be more beneficial.  One could point to the Bengal famine of 1943, when an estimated 2 million people died when the rice crop was attacked by a fungal pathogen. In truth, the vast bulk of food for human consumption worldwide is provided by just fourteen crop plants. Failure of any one of these could have a significant impact on global food security. However, we are in a very dark place indeed if we must look for a catastrophic crop failure to remind consumers of the value of plant biotechnology in protecting our food supply.

Why the Irish Potato Famine was not caused by a fungus

During the long, wet summer of 2012 (perfect late blight weather!), I gave a short public talk about the potato and late blight as part of the Taste of West Cork Festival in Skibbereen, Co. Cork.

The panel of speakers also included the excellent and informative broadcaster Éanna ní Lamhna (of RTE radio fame) who spoke about the history of the potato as well as the history of the Irish potato famine.

Despite the argument that political and economic issues had a great role to play in the Irish potato famine, there is no doubt that the loss of the potato crop due to late blight was the trigger that started it all.

Late blight was, and is, caused by the plant-pathogenic organism Phytophthora infestans which, unfortunately, many people describe as a 'fungus'.

Éanna ní Lamhna described it as such during her talk and I, humorously and good-naturedly (I think!), pulled her up on it. As you can imagine, given that much of the audience had come to see and hear the delightful Ms. ní Lamhna and not some young upstart like me, I had to thread very carefully and there was much friendly banter.

Speakers at the 'Humble Spud' talk

You can't blame anyone for making the mistake - P. infestans is often described as a fungus by those who really should no better.

Browsing through the excellent Atlas of the Great Irish Famine (Cork University Press) recently, I noticed the disease-causing organism is described in several places therein as a 'fungus'.

In a news report in a January issue of the journal Nature, P. infestans was described as "an organism similar to, and often grouped with, fungi". If the author meant that it is often grouped or lumped-in with fungi on a casual (and incorrect!) basis, she's quite right, but as we now know, the organism is not grouped (i.e. classified) as a fungus by fungal taxonomists.

The minutiae of fungal taxonomy is not something we should get bogged down in here (although some would argue that that boat has sailed!), but P. infestans is classified as an oomycete and can be found in the same kingdom as the brown algae and diatoms. Although it may have started out in the Fungi kingdom, it is now firmly categorised as a 'fungal-like organism'.

Damage caused by late blight of potato (APSNET)

A letter in this week's issue of Nature, taking issue with the original news report, states: "It was Anton de Bary, the father of mycology, who coined the genus name Phytophthora ('plant-destroyer') and classed the pathogen as a fungus. But modern molecular sequencing indicates that his interpretation was incorrect"

"The organism is actually an oomycete, a pseudo-fungus that evolved from killer ancestors in the ancient oceans and not from wood-degrading fungi", concluded the author.

Within mycology (the study of fungi), there is some debate over the use of the term fungus. While none would argue against the weight of molecular evidence that clearly puts P. infestans outside the Kingdon, some would argue that, since they are of interest to mycologists and they share many of the common morphological features of fungi, a broader defintion of the term is required.

Money (1998) has argued that the term fungus should have two distinct meanings: (1) the strict taxonomic name used to describe organisms from the Kingdom Fungi and (2) a practical reference to organisms studied by mycologists that share similar characteristics to fungi.

Somehow, I think the taxonomists would disapprove, and so would I.

In praise of the potato

Image: Courtesy of the Southern Star. Details below.

I was delighted to take a trip to Liss Ard Estate, just outside Skibbereen, West Cork, yesterday to speak about the potato plant at a seminar organised by A Taste of West Cork Food Festival.

The panel of speakers for the event included Regina Sexton of UCC, Madeline McKeever of Brown Envelope Seeds and Éanna ní Lamhna, author and RTE radio contributor.

Éanna opened the evening with an informative and exciting summary of the history of the potato and its arrival in Ireland. This was followed by Regina Sexton's presentation on the potato as a food item amongst both the rich and poor in Ireland.

Madeline McKeever spoke of her experience as an organic grower based in West Cork and about the interesting work done by the Sarvari Research Trust to breed blight-resistant potato varieties.

My own talk centered on the historic and present-day impact of late blight on the potato crop and the recent advances in the science of the potato.

I pointed out that an “arms race” now exists between the late blight-causing pathogen Phytophthora infestans and those who would seek to control it. The pathogen’s genome, its genetic blueprint, was sequenced in 2011 and this shows us that it is an incredibly flexible and rapidly-adapting organism. As we develop new fungicides or resistant potato varieties to control late blight, it is just a matter of time before Phytophthora infestans evolves to overcome these barriers.

We have a number of options for the future including the development on new, blight-resistant potato varieties. These varieties can be developed via conventional breeding methods: for example, Teagasc developed the highly successful Rooster variety via its breeding programme and that potato now accounts for about 50% of all potatoes grown in Ireland. Unfortunately it’s not fully resistant to late blight.

Resistant varieties do exist and they are often employed in an organic setting: sarpo mira, blue Danube, etc. However, consumers are reluctant to change from the traditional varieties.

As expected the issue of the recent planting of GM blight-resistant potato plants in Ireland was raised by a number of audience members. I expressed my view that a small-scale, well-designed, open and honest experiment such as this, conducted by a well-respected public body such as Teagasc is to be welcomed.

Opponents of GM often call for more information and more testing to be done on GM plants. This is exactly what the Teagasc experiment is designed to give us.

We must use all the tools at our disposal: organic, conventional and GM to control late blight and protect the potato, a plant which has huge social, historical and economic importance for this country.

The event concluded with a sampling of some delicious potato-based recipes (the lemon potato cake was particularly to my liking) as well as some gripping drama provided by the Skibbereen Theatre Society. All in all, a wonderful celebration of the potato plant.

A Taste of West Cork Food Festival continues this week. More details of other events.

Image: Speakers and organisers of the "Humble Spud" event at Liss Ard. Image courtesy of the Southern Star. Seated (l-r) Madeline McKeever, Regina Sexton, Éanna ní Lamhna, Eoin Lettice. Standing (l-r) Michael Hurley (Chair) and Kay Quinn (Organising Committee) 

Read the Irish Examiner's coverage of the event here.

GM trial gets go-ahead

A genetically modified potato variety will be planted in Ireland as part of a Teagasc-led experimental trial, which has today got the 'green-light' from Ireland's Environmental Protection Agency (EPA).

This post also appears on the Cork Independent Blog.

The field trials were allowed to proceed after an assessment of the experimental plans and designs by the EPA and a broad-ranging consultation process. The EPA also received 83 representations from interested parties - all objecting to the proposed trials. I've previously written about why, I think, this trial is needed.

Teagasc applied for a liscence to plant the potatoes back in January. These plants contain a gene which makes them resistant to late blight (Phytophthora infestans) - the organism which caused the Irish potato famine. This gene has been taken from a wild, related potato variety and inserted into the cultivated potato using GM technology.

The EPA have given their consent to the trials subject to eight conditions, saying in their decision: "The agency believes that the risk to human health and the environment from the deliberate release of these GM potatoes is negligible".

The conditions include a requirement of Teagasc to monitor the experimental site for at least four years after planting. They also require Teagasc to report to the EPA every two months on the progress of the experiments and to set up a 40m exclusion zone around the site where no commercial potato planting can take place.

This trial will ensure that we can have real experimental data, based on Irish conditions, so that we can sensibly assess the impact of GM potato planting on the environment under closely monitored and controlled conditions. From reading through the large number of submissions, it is clear that a large number of those objecting are calling for "more information" before such planting takes place. They seemingly fail to see that this trial is specifically design to provide that information they crave; and to do so in a safe, controlled and carefully-monitored fashion.

There will be a large amount of hyperbole written and spoken about this decision in the next few days. Already, the Organic Trust has warned of "grave ramifications" and a Green party spokesman has suggested it will do "untold damage to Irish farming". On the other hand, those welcoming the decision may talk of feeding the world and food security. In reality, the product of this decision will be far less clear-cut. We will hopefully learn more about how GM plants work in the Irish environment and those who support or oppose GM will continue to argue their own side of the debate.

I believe this is a positive step forward however. This experiment will provide real results which can only add to, enrich and enlighten what is an already heated debate. I look forward to seeing the results of this experiment.

GM Potato set to be planted in Ireland

A major new EU study is set to examine the effects of growing GM, blight-resistant potato plants on biodiversity and the environment in agricultural ecosystems. It will also see the first GM crops being grown in Ireland since the late 1990's.

In a statement issued at the end of February, Teagasc (the Irish agricultural development agency) announced that they are to seek a license to carry out field trials of GM potatoes as part of the AMIGA consortium - a group including representatives of research bodies from 15 EU countries.

Late Blight, caused by the fungal-like organism Phytophthora infestans, decimated the Irish potato crop  in the 1840s leading to the Great Famine. Since then, it has remained a problem for Irish farmers, requiring chemical fungicides to be used to maintain Irish potato yields. GM potatoes have the potential to protect the potato plant from Late Blight attack without the necessity for large amounts of fungicide to be applied.

The potato variety Desiree was transformed withe the Rpi-vnt1.1 gene which confers broad spectrum resistance to Phytophthora infestans. That gene, along with its own promoter and terminator regions were taken from the wild potato species Solanum venturii and inserted into the cultivated potato using Agrobacterium tumefaciens-mediated transformation.

While there are indications that public concern over GM crops has declined in the UK, the news that field experiments will be carried out in Ireland for the first time since the late 1990s has drawn some criticism here.

In a statement released last week, Irish Organic Farmers and Growers Association (IOFGA), called the experiments planned for Teagasc's Oakpark headquarters a waste of taxpayers money. "In light of the fact that Teagasc has lodged an application with the EPA (Environmental Protection Agency) for a licence to grow GM potatoes at its headquarters in Oakpark, IOFGA are demanding that Teagasc be held accountable for their decision to waste taxpayers money on this project."

File Photo: Minister Ruairi Quinn at an Anti-GM event last year

Grace Maher, Development Officer with IOFGA said that considering growing GM in Ireland is "economic suicide" and that the move would put at risk an export market worth 9.1 billion: "Ireland has an excellent reputation internationally as a clean green island that is also a GM free region, and we need to build on this reputation not destroy it”.

The statement ends by accusing Teagasc of pedalling an "unwanted technology":
"In this austere economic climate we need to end wasteful public spending immediately and enforce accountability on those who continue to do so."

Unfortunately, it seems the lobby group for the organic industry, is jumping the gun a bit here.

The funding comes directly from the EU's FP7 research programme - a €50 billion fund specifically designated for research and technological development. There is no question of further money coming from Irish taxpayers.

No matter where the money comes from, there is also a wider issue. Teagasc is Ireland's agriculture and food development agency. It is that organisation's role to carry out research leading to a better understanding of agriculture and new agronomic techniques. To accuse such a body of "wasting" money by doing the very thing is was set up to do, is ridiculous. Any arguments for or against GM crops need to be based on firm scientific evidence and that does not simple fall out of the sky.

The field tests to be carried out at Oakpark will look at the impact of GM plants on the surrounding ecosystem and John Spink, Head of Crops Research at Teagasc was keen to point out that the research is "not about testing the commercial viability of GM potatoes".

"The GM study is about gauging the environmental impact of growing GM potatoes in Ireland and monitoring how the pathogen, which causes blight, and the ecosystem reacts to GM varieties in the field over several seasons.”

Mindful of the controversy surrounding trials of GM sugar beet in Ireland in the late 1990s by Monsanto, these new experiments will use a potato developed at Wageningen University in the Netherlands and there will be no biotech or GM company involved. The sugar beet trials ended with a number of the sites being destroyed by a group styling itself the Gaelic Earth Liberation Front.

According to documents submitted to the EPA as part of the licence application, the field experiments are designed to measure the impact of GM potato cultivation on bacterial, fungal, nematode and earthworm diversity in the soil compared to a conventional system; to identify positive or negative impacts of GM potato on integrated pest management systems; and to use the project as a tool for education in order to engage and discuss the issues surrounding GM with stakeholders and the public.

As Teagasc researcher Dr. Ewen Mullins put it: “It is not enough to simply look at the benefits without also considering the potential costs. We need to investigate whether there are long term impacts associated with this specific GM crop and critically we need to gauge how the late blight disease itself responds. This is not just a question being asked in Ireland. The same issues are arising across Europe.”

Speaking to the Irish Examiner, Dr. Mullins remarked: "People are asking about the merits of GM potatoes.At Teagasc, we have a remit to inform people. We haven’t had GM field trials here since the late 1990s. The goal is to look at all of the environmental impacts, and to fill the vacuum that exists currently in terms of impartial knowledge."

An edited version of this article appears on the Guardian's Notes and Theories blog. You can read it here.

BASF Moves Plant Biotech Jobs to America

The global biotech and chemical company BASF is to withdraw from Europe and concentrate its plant biotechnology business on North and South America. 140 jobs in Europe will go.

Just when science, technology and biotechnology, in particular, have the capacity to create jobs, build confidence in economies and promote an economic recovery, Europe now risks becoming known for an anti-science agenda.

The company said today that it will halt development and commercialisation of all products targeted solely at the European market because of "a lack of acceptance for this technology" from the majority of consumers, farmers and politicians.

BASF say they are "convinced that plant biotechnology is a key technology for the 21st century" but at this time the "conditions for cultivation of genetically modified crops in Europe are unfavourable".

The move will stop development on Europe-targeted crops such as Amflora, a genetically modified potato variety which provides easy to extract starch for industry. The company will also halt work on its Fortuna potato variety, bred to be resistant to late blight, Phytophthora infestans. BASF had applied for approval from the EU for commercial cultivation of Fortuna late last year. The variety had two resistance genes inserted from a wild relative found in South America.

Despite ceasing development of other such products, BASF have said they will continue with the regulatory approval process already in train.

Greenpeace have welcomed the move claiming that "Europeans don't want GM crops, and for good reason".

Marco Contiero, Greenpeace's agriculture policy director said that it wasn't just health concerns that worried EU consumers; "GM crops go hand in glove with factory farming, pesticide use, pest resistance and disappointing long-term yields".

Today's development sees a company with European origins having to move much of its research and development to the Americas due to continuous delaying and buck-passing when it comes to GM regulations in Europe.

This has created an atmosphere where even the research and development of GM crops, for one company at least, has become impossible.

Potato Could Reduce Blood Pressure

Scientists report that just a couple servings of spuds a day reduces blood pressure almost as much as oatmeal without causing weight gain. Scientists reported on the research, done on a group of overweight people with high blood pressure, at the National Meeting & Exposition of the American Chemical Society (ACS), in Denver, Colorado this week.

The bad news is that the research was not done with chips or fries, but with potatoes cooked without oil in a microwave oven. Although researchers used purple potatoes, they believe that red-skin potatoes and white potatoes may have similar effects.

"The potato, more than perhaps any other vegetable, has an undeserved bad reputation that has led many health-conscious people to ban them from their diet," said Joe Vinson, who headed the research. "Mention 'potato' and people think 'fattening, high-carbs, empty calories'. In reality, when prepared without frying and served without butter, margarine or sour cream, one potato has only 110 calories and dozens of healthful phytochemicals and vitamins. We hope our research helps to remake the potato's popular nutritional image."

In the new study, 18 patients who were primarily overweight/obese with high blood pressure ate 6-8 purple potatoes (each about the size of a golf ball) with skins twice daily for a month. They used purple potatoes because the pigment, or coloring material, in fruits and vegetables is especially rich in beneficial phytochemicals including phenolic acids, anthocyanins and carotenoids. Scientists monitored the patients' blood pressure, both systolic (the higher number in a blood pressure reading like 120/80) and diastolic. The average diastolic blood pressure dropped by 4.3 percent and the systolic pressure decreased by 3.5 percent, said Vinson, who is with the University of Scranton in Pennsylvania and has done extensive research on healthful components in foods. The majority of subjects took anti-hypertensive drugs and still had a reduction in blood pressure. None of the study participants gained weight.

Vinson said that other studies have identified substances in potatoes with effects in the body similar to those of the well-known ACE-inhibitor medications, a mainstay for treating high blood pressure. Other phytochemicals in potatoes occur in amounts that rival broccoli, spinach and Brussels sprouts, and also may be involved, Vinson added.

high cooking temperatures seem to destroy most of the healthy substances in a potato Unfortunately for French fry and potato chip fans, those high cooking temperatures seem to destroy most of the healthy substances in a potato, leaving mainly starch, fat and minerals. Potatoes in the study were simply microwaved, which Vinson said seems to be the best way to preserve nutrients.

The purple potatoes used in the study are becoming more widely available in supermarkets and especially in specialty food stores and farmers' markets. Vinson said that he strongly suspects a future study using white potatoes, now in the planning stages, will produce similar results.

Potato Genome Sequenced

The potato genome has just been published in the journal Nature.

The Potato Genome Sequencing Consortium (PGSC), an international team of scientists including some from Teagasc in Ireland, has published the "genetic blueprint" for the world's third most important food crop.

Scientists say the information will help plant scientists and breeders to improve yield, quality, nutritional value and disease resistance pf potato varieties. The PGSC say it should also allow potato breeders "reduce the 10-12 years currently needed to breed new varieties".

The potato genome is the first sequence of an Asterid to be published - a group of flowering plants encompassing around 25% of all known plant species.

The consortium published a draft sequence in 2009 after a meeting of the consortium in Oakpark, Carlow in Ireland to plan the final phases of the project. The most recent publication is a refined version covering approximately 95% of all the genes in the potato - around 39,000 genes that code for proteins.

Worldwide, it's estimated that a loss of about €3 billion per year in the potato crop arises from diseases such as late blight and potato cyst nematodes. These problems are still largely controlled by frequent applications of fungicides and nematicides.

An indepth knowledge of the genetics of the potato should allow scientists to develop new varieties which show high levels of resistance against these pests and diseases.

The potato genome has 12 chromosomes and an extimate 840 million base pairs.

Speaking on the release of the first draft, Professor Jimmy Burke, head of Teagasc Crops Research Centre and leader of the plant biotechnology programme said: “Research such as this is incredibly important to the future competitiveness of Irish agriculture and puts Teagasc at the forefront of exciting developments in science”.

Combining our expertise in plant breeding with cutting-edge biotechnology-based research is enhancing our ability to develop plant varieties suitable for Irish conditions and agricultural practices. We are pursuing similar projects in other species important to agriculture here in Ireland, including perennial ryegrass, white clover and wheat, and energy crops, and we expect similar successes in these species in the future”.


The Nature paper is available here.
The full sequence is available here.

The Potato and Walter Raleigh: Never let the facts spoil a good story

I've got a particular interest in potatoes. Lots of my research is based on dealing with potato pests, so I've got an affection for the tuber.

That's why I was so excited to see a new website, potato.ie launched to promote the Irish potato as 'Ireland's Feel-Good Food'. Take a look, it's full of recipe ideas, fun facts and information about Solanum tuberosum.

If I've got one complaint, it is that the website highlights the supposed connection between Sir Walter Raleigh and the potato. A connection which is just not supported by the facts.

Under the the 'History' section of the website, they note that "popular myth credits its introduction at Youghal, Co. Cork by Sir Walter Raleigh. Other anecdotal evidence suggest that the potato was washed up on the shores of Cork after the wreck of the Spanish Armada in the area".

To be fair to the Irish Potato Federation, they make it clear that they consider the Raleigh story an urban (or should that be rural?) myth and so it is.

The potato originated in South America and what is at question here is how it got to Europe and, in particular, how it got to Ireland and the UK.

The Walter Raleigh myth is a really nice story and in many ways, I'd really like it to be true, but academics and historians are pretty sure that it's not. The story 'dies hard' though due to is widespread publicity and legendary status.

The most likely theory for the introduction of potato to Ireland and Britain is that it arrived from Spain. The author William Coles wrote in London in 1657 about “the potatoes which we call Spanish because they were first brought up to us out of Spain, grew originally in the Indies…”

Even as far back as 1727, there was clearly a view that the potato came from Spain (and indeed there was people willing to reject that argument). The Anglo-Irish botanist Caleb Threlkeld wrote pompously:

“Those who would give to the Spaniards the honour of entrencing (sic) this useful root called the potato, give me leave to call designing parricides, who stirred up the mislead zeal of the people of this kingdom to cast off the English government which is the greatest mercy they ever enjoyed… To ascribe the honour of the English industry to the effeminate Spaniards cannot be passed over without remark… and if I might advise the inhabitants, they should every meal they eat of this root be thankful to the Creator for English navigation.”

"every meal they eat of this root be thankful to the Creator for English navigation"What a wonderful rant! But perhaps he protests too strongly? It's useful to note that nowhere does Threlkeld mention Raleigh to back up his assertions. Surely if the Raleigh myth was in play back in 1727, the author would have played it as his trump card? This suggests that Raleigh's name was introduced at a later date to support this argument.

The Spanish theory is also supported by Irish oral tradition.Seán O Neachtain wrote the poem Cáth Bearna Chroise Brighde (The Battle of the Gap of St. Bridget’s Cross) in 1750 and this clearly supports the Spanish theory.

The poem is a very lengthy account of a fictional battle, which takes place near Tallaght in Co. Dublin (the poem extends to 218 short verses).

In it, O'Neachtain refers to the potato as "An Spaineach Geal" - the kind-hearted Spaniard and refers to its supporters as "the friends of the Spaniards". At the beginning of the poem, the poet mourns the loss of "my dear Spaniard" saying his death will be "death for the gaels, woe to them all".

Clearly then there were cultural references to the Spanish Introduction in 18th Century Ireland. When exactly Raleigh's name became involved in the story is unclear. Brewer (1826) certainly links Raleigh to the introduction and says it happened in 1588 when Raleigh was Mayor of Youghal.

Whatever the truth, the Raleigh myth is an endearing one and there is little doubt that the southwest of Ireland is a location were potato cultivation was understood and practiced at an early stage, perhaps because of the mild climate. It is possible that Raleigh was used as a figurehead for those wanting to give the vegetable a more 'appropriate' or British image in light of its connections to Spain.

As a piece of fiction, the Raleigh myth is a great one, but we shouldn't confuse fact with fiction, even if it does spoil a good story.

How to create GM crops

Scientists at the Sainsbury Laboratory explain how they have produced blight-resistant potatoes using plant tissue culture. For more on this story, see our earlier post.

Anti-GM campaigners can't have it both ways

British scientists are to set up a 1,000-square-metre plot of genetically modified potatoes in Norfolk. The potato plants have been genetically modified by scientists at The Sainsbury Laboratory (TSL) to be resistant to "Late Blight" which is caused by a fungi-like organism called Phytophthora infestans.

The experiment is designed to tell whether GM potato plants that are resistant to late blight in vitro (that's in the laboratory) are also resistant to the pathogen in vivo (i.e. in the field), where there are a much larger number of different strains of P. infestans. If a fully resistant potato variety can be found, it could at least put a dent in the estimated £3.5 billion worth of losses that the disease causes worldwide every year.

Much of that cost is related to the use of fungicides - chemicals used to control fungi or fungi-like organisms. (By the way, although it's most appropriate to refer to P. infestans as a "fungi-like organism" and not as a fungi, the difference is very minor and one with which we need not concern ourselves here.)

Professor Jonathan Jones of TSL explains: "We have isolated genes from two different wild potato species that confer blight resistance Similar genes are found in all plants, and we are now testing whether these ones work in a field environment to protect a commercial potato variety, Desiree, against this destructive potato disease".

The group of scientists screened about 100 different wild species of Solanum, the grouping of plants to which potatoes belong and identified just a handful that were resistant. The next step was to isolate genes and insert them into the commercially available potato variety Desiree. Watch a video of the process here.

The modified plants can now recognise the onset of late blight attack and can trigger the plant to switch on its own defence mechanisms. By switching on these plant-based defences, it may drastically reduce the levels of fungicide which need to be applied.

Despite this good news, anti-GM campaigners have once again come out against such trials. Kirtana Chandrasekaren, Friend of the Earth's Food Campaigner accused the British government of "wasting millions of pounds of taxpayers' money by forging ahead with unnecessary and unpopular GM trials.
"We can feed a growing global population without trashing the planet or resorting to factory farms and GM crops - the Government must help farmers shift to planet-friendly farming" said Chanrasekaren.

Dr. Helen Wallace of the campaign group GeneWatch also called the trial a "waste opf public money" and suggested that "it is possible to breed blight-resistant potatoes using conventional methods, so there is no need to use GM technology".

"anti-GM campaigners need to make a choice"What Dr. Wallace and the campaign groups fail to grasp is that it has been nearly 160 years since the end of the Irish Potato Famine when one million people died of starvation and further one million people emigrated to survive. In those 160 years of conventional breeding, a tiny handful of varieties have been produced with full resistance to the pathogen and their propagation has been severely limited by consumers opting for older, more familiar varieties.

So, anti-GM campaigners need to make a choice. Either we stick with existing varieties and pump millions of tonnes of fungicides into them every year or we opt for a slightly modified version of a commercially relatively successful variety which can defend itself from late blight, reducing fungicide use significantly in the process. The campaigners can't have it both ways.

A previous post on this blog also dealt with the issue of consumer acceptance of GM crops.

Tasty spuds need not be organic

A group of Irish scientists have shown that there is no difference in taste between organically and conventionally grown potatoes.

In a study published in this month's edition of the International Journal of Food Science and Technology, Clare Hilsenan, Roisin Burke and Catherine Barry-Ryan from Dublin Institute of Technology, reported that a panel of consumer tasters could find no significant difference between organic and non-organic potatoes.

Organic potatoes (of the cultivar Orla) were grown near Navan, Co. Meath and were fertilised with composted manure rather than the synthetic fertiliser applied to the conventional potatoes (also grown in Navan). Since potato blight (caused by Phytophthora infestans) is a serious fungal pest of potatoes in Ireland, the conventionally grown spuds were sprayed with a liquid copper fungicide designed to control the fungus. Since such synthetic additives are not permitted in organic agriculture, the organic potatoes were treated with Burgundy (a mixture of copper sulphate and washing soda).

Despite Burgundy currently being permitted in organic agriculture (like the related Bordeaux mixture) there are some doubts about the impact repeated applications of a copper-based treatment has on the local environment to which it is applied. Copper sulphate is toxic to some fish and if it finds its way into water bodies, can cause significant problems. It has also been shown to cause problems for bees, sheep, chickens and especially earthworms who are crucial for proper soil health and therefore the success of an organic agricultural system.

However, the use of Burgundy is a side issue and the study in question deals with the eventual taste of the harvested potatoes.

The potatoes from both sources were taken to the laboratory and baked in the oven.The colour, texture and the dry matter content of the  potatoes were measured as well as the pH and the amount of sugar present in the samples.

"tasters were asked to assess flavour, texture and aroma"Then comes the fun bit. A group of ten tasters (trained to international standards!) were asked to assess the flavour, texture and aroma of the raw and cooked potatoes. This involved them sitting in specially constructed booths were the temperature and light was controlled to insure that they were influenced by outside interference. As well as that, the order in which the samples were tasted were randomised in order to ensure that each had an equal chance of being first or last.

As well as these specially trained tasters, a panel of 80 regular potato eaters was gathered from amongst the staff and students of DIT and asked to assess cooked potatoes under the headings colour, aroma, texture and taste.

"some chefs may not agree with us" - Roisin Burke, DITThe results of the taste-tests were analysed and make for interesting reading. The trained panel of tasters found the organic potatoes to be harder, and drier than the conventionals.In terms of colour, aroma and taste, no significant differences were found between organic and conventionally grown samples.

When the 'untrained' consumer panel reported, they again found no statistical differences in the appearance, aroma, texture and taste.

Since the price difference between organic and conventionally- grown fruit and vegetables is sometimes staggering, these results indicate that taste should not be a factor in our decision if we choose conventional over organic potatoes. An analysis by the Sunday Times showed that 1 kg of organic potatoes cost €2 in Tesco this week compared to €1.06 for 1 kg of conventional spuds.

Speaking to that newspaper, one of the authors Roisin Burke noted that "some chefs may not agree with us" and that "There are other reasons why people eat organic potatoes, such as the lack of pesticides, but we found no difference in taste.”

Communicate Science @ guardian.co.uk

The good people at guardian.co.uk have published one of the articles from Communicate Science as a science blog on their website. The article deals with the recent decision by the EC to allow GM potatoes to be cultivated in Europe as well as consumer opinion on GM in general. The article, which is an edited version of the post that appears on this blog, can be viewed here.

Second generation GM can't come soon enough

This week’s decision by the newly-installed European Commission (EC) to allow genetically modified (GM) potato varieties to be grown in some EU countries brings to somewhat of a conclusion, a 13-year campaign by the German chemical company BASF.



An edited version of this article appears on the Guardian.co.uk Science Blog. View it here.

The potato in question, Amflora benefits from the gene for a particularly uneconomic form of starch (amylose) being turned off by genetic modification. This means that the useful starch that is produced (amylopectin) doesn’t need to be separated from the useless form.

The starch is used in the paper, textiles and adhesives industries. BASF say that while the starch will not be used in human food, they may use the product in animal feed.


Amflora also carries an extra gene called neomycin phosphotransferase II (nptII) which makes the potato resistant to the antibiotics neomycin and kanamycin. This ‘antibiotic resistance marker gene’ has provoked much debate and is focused on by opponents of GM technology.


In June 2009, the European Food Safety Authority (EFSA) concluded that these marker genes, including nptII are unlikely to cause adverse effects on human health and the environment, but due to limitations to sampling and detection they were unable to be conclusive. They did however re-emphasise that they considered Amflora to be safe.



"Insertion can be achieved by using a bacterium to “ferry” the gene into the plant cell or by blasting it in using a gene gun"The antibiotic resistance marker genes are a remnant of the genetic modification process that produced the potatoes in the first place. GM plants are produced by inserting novel genes into individual plant cells and then growing the plant cells into whole plants in the laboratory. Insertion can be achieved by using a bacterium to “ferry” the gene into the plant cell or by blasting it in using a gene gun. Alternatively, the tough plant cell wall can be stripped off and the gene can be inserted into this “naked” cell.



Whatever way it is inserted, not all of the plant cells treated will successfully take up the new gene and incorporate it into its own DNA; perhaps just 5 cells out of every 1000 in particularly susceptible plants. It is necessary therefore to be able to select those cells which have been modified from those which have not.


By not only inserting the novel gene, but also tagging a marker gene onto it, it ensures that cells which have been successfully modified exhibit resistance to a specific range of antibiotics. In the case of Amflora, it means that only those plant cells which will grow in the presence of kanamycin and neomycin have been successfully modified. The successful cells can then be allowed to grow into whole plants. However, these whole plants will contain the antibiotic resistance genes in every one of its cells.


BASF first submitted its Amflora potato for approval in 1996 but an EU-wide moratorium on GM between 1998 and 2004 delayed the process substantially. When the potato was resubmitted for approval after the moratorium ended, progress was so slow that BASF took the EC to court in 2008 to force them to come to a decision.


The chemical company filed an action against the EC in the European Court of First Instance for “failure to act” and decide on the issue despite the EFSA saying in two separate reports that the product had no harmful effects on human health and was as safe as any conventional potato. The company claimed that the previous commissioner, Stavros Dimas, “unjustifiably delayed” the decision on several occasions.


Now, within weeks of stepping into the role, the new European Commissioner for Health and Consumer Policy, John Dalli, has given the green light for planting to begin. BASF say the potatoes will be grown in Germany and the Czech Republic this year as well as Sweden and The Netherlands in 2011.


Opponents of GM technology have been quick to denounce the decision, with Greenpeace saying that Dalli has “steam-rolled” a decision through. Given that the potato variety in question has undergone 13 years of testing since its first submission, this analogy of a steam-roller might be better applied to the lumbering decision making process in Europe rather than this final decisive move by the new Commissioner.


At the crux of this issue is the consumer’s opinion on GM foodstuffs and GM organisms in general. Consumers genuinely do not see the benefit for them of using GM products.


"there is a need to move beyond GM crops that confer benefits to industry and growers alone and towards second generation GM"For this reason, there is a need to move beyond GM crops that confer benefits to industry and growers alone and towards second generation GM which produces added health and nutritional benefits for consumers. The president and CEO of BASF Plant Science Dr. Hans Kast is on record as saying that the Amflora potato represents a potential added value to European farmers of €100 million annually. The company has also pointed out that they are loosing between €20 and 30 million in license income for every lost cultivation season.



Perhaps I’m being presumptuous, but I can’t imagine many Irish or European consumers laying awake at night worrying about lost revenues for BASF. What Irish consumers are concerned about however, are real and tangible benefits from their foods.


In a study carried out in 2005, 42% of Irish consumers surveyed indicated that they would be willing to purchase a hypothetical GM-produced yoghurt if it had anti-cancer properties. In the same study, 44% of consumers said that they would use a GM-produced dairy spread if it had anti-cancer properties.


These second generation GM crops also have a role to play in developing countries, with the development of biofortified foodstuffs to counteract micronutrient malnutrition among the poor.


Undoubtedly, some British and Irish consumers, in common with their European counterparts are reluctant to consume GM crops and see them grown in their countries. The focus of industry on benefits to the grower and seed producer rather than on consumer-centred benefits will prolong this reluctance and hamper the innovation in our food and agriculture industries which is so badly needed at this time.