ISIS Report 12/07/10
GM Blight-resistant Potatoes – Who Needs Them?
While researchers are wasting taxpayers’
money to create hazardous GM blight-resistant potatoes, non-GM highly
blight-resistant varieties are already on the market, with low carbon impact
and all-round appeal to consumers Dr Eva Novotny
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version of this paper is posted on ISIS members website
and can be downloaded here
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A new trial of genetically modified (GM)
crops has begun in England . The Sainsbury Laboratory at the John Innes Centre in Norfolk is testing a GM
version of the popular Desiree potato to determine whether, as in the
laboratory, the field-grown GM potato will remain resistant to late-blight
disease. The challenge to develop such potatoes had already
been taken up in 2007 by the German chemical giant BASF, in its Plant Science
GmbH division; but their trials ended prematurely without a marketable result.
In fact, all such efforts are unnecessary, as blight-resistant non-GM potatoes
already exist that are also outstanding in other respects, and further such
varieties are in the pipeline.
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Late blight is a serious disease of
Late blight is “ the most devastating
disease of potatoes and one of the most devastating plant diseases of any crop
[2, 3].” In the UK, farmers typically spray potato crops with fungicide 10-15
times a year . Much effort, therefore, has been put into means of
controlling the disease. As part of good farming practice, it is clearly
advantageous to plant blight resistant varieties.
The disease can
kill all the leaves of a plant within 10 days. It was the cause of the great
Potato Famine in Ireland and western Scotland in the 1840s and 1850s. The
pathogen responsible is Phytophthera infestans, notionally a fungus but
actually more closely related to brown seaweeds. Warm, humid weather favours
the disease. Leaves and stems can be infected, as can the tubers when spores
are washed into the soil by heavy rain. The disease can be carried from year
to year by tubers that were infected in the previous season. Although soil is
not usually a source of the blight, it is possible for the disease to be
transmitted when both mating types of the blight pathogen (see  GM Potatoes not
Proven Safe for Release, SiS 47) are present
in the soil. In gardens, it is possible for the disease to be carried over on
infected foliage in an insufficiently hot compost heap.
the pathogen is evolving. Until 1976, there was only the single mating type A1,
which had various strains, all reproducing asexually. Then mating type A2
appeared in Europe, brought from Mexico (the probable origin of the blight
pathogens) on imported potatoes. The two types were able to mate and produced new strains by sexual reproduction.
Since 2005, a highly aggressive strain A2-Blue13 has developed; causing blight
in some potato varieties that were previously resistant, and it has become the
dominant strain in the UK. There is always the danger that the pathogen will
evolve into a new strain that can overcome the resistance of potato varieties
now free of the disease, and development of new varieties needs to take place
on a continuing basis.
New trial by the Sainsbury
The Sainsbury Laboratory at the
John Innes Centre in Norfolk, England has received approval for field trials of
GM blight-resistant potatoes, beginning in 2010. The Laboratory claims
that existing non-GM blight-resistant potatoes suffer from “other
deficiencies”, but this claim cannot justly be
applied to Sárpo potatoes, described later.
resistance to blight occurs in some wild, inedible potato species in South
America. Two genes isolated from these have been transferred to a potato
variety popular in Britain, Desiree [4, 5], and will undergo field trials for three years.
the use of genetic engineering to produce the new potatoes, the Laboratory
claims that : “Potato breeding is extremely
slow and inefficient. … Breeding is not an exact science and changes many genes
that affect important agronomic traits such as yield, quality and maturity
By using GM we can be sure that only the
desired resistance gene is introduced into the resulting variety, without
changing other characteristics.” This disingenuous statement is actually
false: it is well known that the random insertion process of genetic
engineering leads to disruption and rearrangement in the host’s own genome,
causing ‘insertion mutagenesis’ in many genes with totally unpredictable
effects (see review in  The Case
for A GM-Free Sustainable World, Independent
Science Panel, ISIS publication).
The GM potato also has an antibiotic resistance marker gene nptII
that confers resistance to kanamycin and neomycin . The Laboratory
claims erroneously that the antibiotic is not used for medical treatment of
either humans or animals. The Advisory Committee on Releases to the
Environment (ACRE) gave an approving opinion for the trials, on grounds that :
“(a) the likelihood of transfer of a functional gene from plant material
tobacteria is extremely low; (b) bacteria with resistance to these
antibiotics arewidespread in the environment; and (c) the acquisition of
an intact gene isonly one of the possible mechanisms by which bacteria
may developresistance.” This is essentially the same
opinion delivered by the pro-GM European Food Safety Authority (EFSA) when it
examined the use of antibiotic resistance genes in food crops. On that
occasion, however, two senior scientists on the panel disagreed and issued a minority opinion in an annex to the statement, saying it
was not possible to assess any adverse effects and that the probability that
the gene could transfer from the GM plants to environmental bacteria was
between ‘unlikely’ and ‘high’ (see  GM DNA Does Jump
Species, SiS 47).
Norfolk trials are funded entirely by UK taxpayers, through the Biotechnology and Biological Sciences Research Council
(BBSRC) . This is unfortunate and a waste of taxpayers’ money, as even a
Monsanto representative acknowledged that “ultimately
[non-GM] biotech offers the greatest potential” for developing crops with such
complex traits .
Another questionable aspect of the
trials, and indeed of the whole project, is that the
parent variety Desiree is already widely planted. Thus, a newly
invading disease affecting the GM potato may wipe out a major portion of the
UK’s potato harvest, both GM and non-GM.
In fact, GM
potatoes for late-blight resistance had already been trialled and abandoned by
another corporation. German chemical company BASF had produced GM
blight-resistant potatoes. Field trials were started in 2007,
originally planned for the Irish Republic but moved to England after the Irish
authorities placed very high requirements on the conduct of the trials,
especially the requirement for safety testing by feeding the potatoes to
animals prior to commencement of trials.
A site at Hedon,
near Hull, was then chosen but was cancelled when the hosting farmer realised
the damage that would result from GM contamination of nearby borage farms,
valuable to bees. Trials did, however, proceed at the National Institute of
Agricultural Botany (NIAB) in Cambridge, despite protest from local residents.
commented on these trials :
“The risk assessment has been granted
using the assumption that these are normal potatoes with a few predictable
genes added. A characteristic feature of transgenic crops is that they do not behave
in such a predictable fashion. The reason BASF is testing so many transgenic
lines is precisely because transgenics are not predictable ... the documents
show an astonishing reliance on assumption-based reasoning.”
Five years of trials were planned at NIAB, but only two
years, 2007 and 2008, were completed; after that, the Cambridge trials were
discontinued. The reason given was the delays in EU approval for GM potatoes:
another variety they were testing elsewhere, Amflora, which produces an
industrial starch, had still not received approval at the time the Cambridge
trials were aborted . Now that the EU has at last given approval for the
cultivation of Amflora , BASF may be encouraged to resume research
in this direction.
Non-GM blight-resistant potatoes
The GM industry has been claiming that
non-GM blight-resistant Sárpo potatoes are not liked by consumers because they
do not taste good and do not boil up well. These allegations were put to the
test in London in March, 2010. A tasting event was organised at the Konstam
Restaurant at the Prince Albert in London, where the chef prepared Sárpo
potatoes in various ways. Invitations had been issued to various groups and
individuals, including supermarkets (with one positive response) and the media
(with one positive response). Four varieties were made available for the
event: Sárpo Mira, Sárpo Axona, Sárpo Una and Blue Danube. Their properties
differ and, as with the common varieties of potato, some are better suited than
others for particular methods of cooking. One variety that indeed does not
boil well nevertheless proved its worth in the tasting event: it made a
delicious soup and also a tempting puree served on small biscuits. Other
Sárpos were made into chips, fries and jacket potatoes. They were unanimously
acclaimed by the participants to be very tasty and deserving of widespread
adoption. The representative of a major supermarket who took part declared
that she would urge her company to market Sárpos.
are now on the UK National List of seeds given approval for commercial sale: Sárpo
Axona and Sárpo Mira were the first to be registered, followed in June 2009 by
four more. All of these are described by the Sárvari
Research Trust, and more are on the way .
“Sárpo Mira and Axona are both high yielding, red-skinned, main
crop varieties with high dry matter. Sárpo Mira makes attractive chips (French
fries) and Axona makes excellent flavoured mash.
“Sárpo Una has good
foliage-blight resistance for an early variety and excellent tuber resistance.
Tubers are rose-pink with a good skin finish. Flesh is white in colour and low
in dry matter making it useful for boiling, gratin and as a salad. Trials have
found good resistance to powdery scab, potato virus Yo, dry rot (F.
sulphureum), black dot, silver scurf and skin spot.
“Sárpo Shona is a blight
resistant and virus Yo resistant, white-skinned variety with early-maincrop
maturity. The short foliage is dense and weed-smothering. Tubers are short
oval and can be prepared in most ways due to their medium dry matter content.
Independent Variety Trials show tubers to have good resistance to black dot and
“Kifli is a long, white-skinned
variety with outstanding flavour when prepared as a freshly harvested, loose-skinned
potato. Plants show medium resistance to late-blight and high resistance to
virus Yo. It has good resistance to splitting and bruising, to blackleg and to
PCN Ro1 [potato cyst nematode].
“Blue Danube has purple-black
stems, shiny dark foliage and spectacular blue-skinned tubers of good shape and
skin finish. It is an early maincrop with medium foliage-blight resistance and
good tuber-blight resistance. It has good resistance to virus Yo and to
leafroll virus, blackleg, dry rot (F. coeruleum) and PCN Ro1. The flesh
is white and of medium dry matter content. Growers experimenting with this
variety always want more – it is developing cult-status.”
Morgan, “Experts in the garden since 1885”, sell three varieties of Sárpo
potatoes, and describe them very favourably .
At the tasting
event in London, Dr David Shaw, Director of Research at the Sárvári Research Trust, said that farmers’ markets and the Prince of
Wales’ estate, Highgrove, “love them”. They are popular in the Duchy box-scheme.
“Glowing reports” come from Ireland; and Wales and Scotland are also becoming
interested in Sárpos.
Environmental benefits of Sárpo potatoes
Not only are Sárpo potatoes a boon to
farmers for their disease resistance but they offer additional benefits,
which importantly include a light carbon-footprint . With natural
resistance to viruses, they rarely require spraying for virus-transmitting
aphids. Their abundant foliage smothers weeds, unless weed infestation is
high; hence spraying of herbicides is not necessary. No spraying against
blight is needed, even in wet seasons such as 2007, when other normally
resistant varieties succumbed. The best Sárpos are resistant to all known
strains of blight. Sárpos can be grown in poor soils with a minimum of added
nutrients. Storage even into late spring requires no refrigeration because of
their long dormancy, nor do they need application of a sprout-inhibitor. In
addition, some varieties have excellent drought tolerance.
The lack of
chemical use on Sárpos contrasts with the heavy use on other potatoes, which
need chemical sprays every 5-7 days or, in a bad season, every 3 days. Even
organic farmers may be forced to apply chemicals, based on copper; however,
these are poisonous and will be phased out in EU countries.
can undoubtedly be grown also outside Europe, particularly in developing
countries where chemical controls for blight are unaffordable.
History of Sárpos
Breeding of the non-GM potatoes began in
Hungary during the days of the Soviet Union . They were intended for
cultivation throughout that bloc; and a hardy strain, resistant to harsh
climate and disease, was required. Research was undertaken at the Keszthely
Institute, which later became the Potato Research Centre at the Pannonia
Georgikon Faculty of Agriculture. The Director was Dr Istvaán Sárvári, who was
joined in the work by his wife; and the family name has been given to Sárpo
potatoes as a combination of Sárvári and potato.
To develop the
high degree of resistance required, wild potatoes from South America and Mexico
were used in the breeding programme to confer resistance to common viruses.
Later, high resistance to late blight was added. In 1994, a Scottish potato
seed grower, Adam Anderson, came upon a potato trial in Romania. The potatoes
had been devastated by blight except for certain plants, which Anderson traced
to the Sárvári family. Anderson and others then formed a company to help
support the breeding programme and built a research station near the Sárvári
family home. Work has continued after the death of Dr Sárvári by his wife and
Research Trust was formed in Wales as a not-for-profit organisation in 2002.
When a promising variety is developed in Hungary, it is sent to Wales for
further testing and commercialisation. To expose the potatoes to as many
different strains of the pathogen as possible, trials are carried out at many
places in the United Kingdom, several European countries and Mexico. In
addition to late-blight resistance, new candidates are tested for “yield; tuber
number, shape and uniformity; resistance to other pests and diseases; foliage
maturity and dormancy; cooking and processing quality and taste”. Continuing
research is necessary to keep pace with evolving new strains of blight.
Why we don’t need GM
Development of a GM crop takes
years of research and trials, and it is an extremely costly process that
includes taxpayer funding. Many hazards to health and the environment are
incurred once the crop is approved for commercialization, and even during field
trials. Evaluation of these hazards by the UK government and by the EU is lax,
relying on data supplied by the seed company
while dismissing the warnings of independent scientists whose own trials show
harm . In contrast, Sárpo potatoes, already on the market and with more to
follow, have all-round excellent characteristics including a low
carbon-footprint. They provide much more value, at far lower cost than those
on trial at the Sainsbury Laboratory. So why do we need GM potatoes at
There are 3 comments on this article so far. Add your comment
|Todd Millions Comment left 14th July 2010 07:07:08|
You can also-plant on new fields every year,and eliminate most spud disease and pests.Hardly new tech. The resilance that can be accieved with Crop rotation is one of the resons its so hard too translate to perrenial crops.
|Rory Short Comment left 12th July 2010 19:07:24|
Commercial interest in GM crops is driven first and foremost by a hunger for money. This primary motivation is not marketable amongst farmers or consumers so GM promoters have to do their best to cloak their real motivation with other benefits that are more attractive to farmers and consumers
|Santhanam R. Comment left 13th July 2010 13:01:19|
Keshava Krishi formulations can produce disease free output for ANY plant and its output as food produce, fuel or fibre. It uses toxic wastes of all kinds usually gathered from nearest locations and applied after a simple enough procedure which any farm hand can do. It of course uses certain proprietary formulations, ingredients which make it work! On the broader perspective it nails the lie that that plants are attacked by pests and so they have to be treated with expensive and toxic concoctions called as pesticides. A plant fed and nurtured properly will grow healthy and shake off diseases and be immune to pests. So the expensive engineering of genes is a lopsided technology which is being practised by people who do not want to understand ways of nature and working in harmony (quote Late Masanobu Fukuoka) with it!