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Recent Hungarian work relating to the environmental effects of
planting MON810 maize in Hungary (reported 2006). When Monsanto
became aware of the damaging impact of this work, it refused to
supply further seed stocks for field experiments, effectively making
replication, verification and extensions of the research impossible.
That in itself is a scientific outrage.
András Székács, Erik Maloschik, Éva Lauber, László A.
Polgár &
Béla Darvas
Hungarian Academy of Sciences, Plant Protection Institute, Department
of Ecotoxicology and Environmental Analysis, Budapest
A several-year monitoring study has been carried out to
measure the quantity of Cry1Ab toxins in DK-440 BTY corn (MON 810
genetic event). MON 810 corn produces an artificial, truncated
version of a Cry toxin (from the family of so-called Cry toxins),
derived from the bacterium, Bacillus thuringiensis with a pathogenic
effect on Lepidopteran insects. Although Cry toxins are compounds
which have gained acceptance in pest control (i.e., in various
biopesticides such as Dipel), genetically modified (GM) plants are by
no means equivalent to these biopesticides from the aspect of
environmental analysis and ecotoxicology. The main difference with
regard to toxin release is related to the extent and duration of
exposition: while biopesticide applications release a small quantity
of the toxin at a single or several occasions, the GM plant produces
the toxin protein on a continuous basis (and unnecessary) during the
entire vegetation cycle, as long as the gene section(s) added
artificially to the plant and responsible for encoding the protein
are active.
Our measurements have confirmed that the Cry toxin is
produced in the plant during the whole period of growth, and is
present to the greatest extent in the leaves. In a dry plant, under
moderate temperature, the toxin remains biologically active for
several years. Following the harvest of the maize, the stubble
contains a significant quantity of Cry toxin. Cry toxin,
overwintering in the stubble, can still be detected in plant residues
after a period of one year.
In order to compare the quantity of Cry-toxin proteins
produced by the Bt-plant with doses registered and permitted for
their use in biopesticides, we also determined the toxin quantity in
Dipel. We found that MON 810 Bt-corn produces 1500-3000 times more
Cry1Ab toxin than the Cry1Ab toxin dose corresponding to a single
treatment with Dipel. Moreover, only part of this toxin from Bt-plant
is decomposed during the growth period.[3] A significant part of the
remaining quantity in the stubble enters the soil, where it may
affect soil life (animals and micro-organisms). Therefore, there is
sufficient ground for a detailed investigation in this field.
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Conflicts of DK-440 BTY corn pollen[4]-[5]
Béla Darvas, Éva Lauber & László A. Polgár
Hungarian Academy of Sciences, Plant Protection Institute, Department
of Ecotoxicology and Environmental Analysis, Budapest
A several-year study has been carried out regarding
possible effects of the pollen of DK-440 BTY corn (MON 810 genetic
event). The investigations were conducted in Nagykovácsi, Júlia-
major, a valley where no maize was grown during the years concerned.
The distance of the intraspecific hybrid formation was examined on
white, tassel-free maize, and we found that in the case of low pollen
production (35 kg/ha), a distance of 800 m could be sufficient to
avoid cross-pollination, with the threshold value for marking being
<0.9%. However, in case of corns with high pollen production (175 kg/
ha), the proportion of intraspecific hybrid formation at a distance
of 500 m was over >1%. Our investigation confirmed the results
published by Andor Bálint in the 1980's.[6] In our opinion, it is
sufficient to stipulate an isolation distance of 800 m between GM and
traditional maize in the Hungarian co-existence regulation. This,
however, is not true for maize on organic farms, where zero tolerance
is accepted for GM-hybrids. According to our measurements, for seeds
developing from a traditional female blossom pollinated with cry gene
containing pollen (i.e., from Bt-maize such as MON 810), there is a
high probability (1/3 part) of Cry1Ab toxin production.
In the case of Bt-corn hybrids with lower pollen
production and with lower amounts of Cry toxin in the pollen, the Bt-
pollen settled down on weeds presents a danger in a range of about 5
m to hatching caterpillars of protected butterflies. At the perimeter
of cornfields in Hungary, the occurrence of nettle (Urtica spp.)
during maize pollination is the third most frequent plant
association. The protected butterfly species which lay eggs on
nettles during maize pollination are the Peacock butterfly (Inachis
io) and the Red admiral (Vanessa atalanta). Nearly a fifth of the
hatching caterpillars of the Peacock butterfly could die in this
perimeter. This means that in case of extensive Bt-corn cultivation,
these two butterfly species could recede from the Hungarian corn
growing areas. Natural biotopes of these species are protected by the
Hungarian Nature Protection Act.
During our investigations with Dipel, the caterpillars of the Peacock
butterfly were shown to be extremely sensitive to Cry toxins. The
caterpillars of the Comma butterfly (Polygonia c-album), which also
live on nettle, are 19 times less sensitive. However, the dose
permitted for use against European corn borer (Ostrinia nubilalis) is
50-times larger than this sensitivity level. On the hatching
caterpillars of the Peacock butterfly, the effect of Cry1Ab toxin in
Dipel is 75 times stronger than the toxin in Bt-pollen. This could be
due to further Cry toxin substances in Dipel, as well as feeding,
digestive and detoxification differences of the species studied.[7]
In Hungary, farmers do not spray against European corn borer larvae,
as this insect is not a significant pest. Therefore, MON 810 corn is
not needed for the Hungarian plant protection practice.
-------------------------------------------------------------
Cry1Ab-resistance pattern on Indian meal moth[8]-[9]
Béla Darvas & Éva Lauber
Hungarian Academy of Sciences, Plant Protection Institute, Department
of Ecotoxicology and Environmental Analysis, Budapest
Investigations to reveal the development of insect
resistance against Cry-toxin were conducted with dry and ground Bt-
corn leaves from the DK-440 BTY (MON 810 genetic event) maize. This
Bt-corn produces Cry1Ab toxin, which causes resistance of the plant
to European corn borer (Ostrinia nubilalis). Experiments were started
on a laboratory model animal, the Indian meal moth (Plodia
interpunctella), and 35 generations of which have been raised by
December 2005 under specific selection pressure.
The continuous treatment resulted in neither
morphologically or anatomically detectable changes, nor observable
developmental abnormalities in any of these 35 generations. However,
results worthy of consideration have been found with regard to the
changing reactions of animals under treatment:
- In the 4th generation, the stock under treatment already showed
tolerance to a quarter-dose of Bt-corn leaves (this is approximately
equivalent for the Cry1Ab toxin content of the corn stem), while in
the 10th generation, the population survived the half-dose of the
toxin content in Bt-corn leaves. By the 20th generation, the
developmental parameters (male and female pupae weights, as well as
pre- and postembryonic developmental times) were normalized.
- In the 30th generation, the Indian meal moth population resistant
to Cry1Ab toxin showed cross-resistance to the biopesticide Dipel,
which contains several types of Cry1 and Cry2 toxins. The growth of
tolerance was almost four-fold.
- When the selection pressure was abandoned during 10 generations,
the acquired resistance persisted, which shows that the change is
inheritable.[10]
Our investigations show that Bt-corn varieties could
have a relatively short time of expiration. This will generate the
problem that there will be a growth in the number of insect
populations on which Bacillus thuringiensis products - used almost
exclusively in organic farming - will no longer have a suitable
effect.
[1] Székács, A. et al. (2005) FEBS Journal, 272 Suppl. 1: 508;
http://www.blackwellpublishing.com/febsabstracts2005/abstract.asp?
id=41771
[2] Székács, A. et al. (2006) Abs. 52th Hungarian Plant Protection
Days, 52: 32; http://www.fvm.hu/doc/upload/200602/
ntn_2006_kiadvany_2006_02.pdf
[3] Granted by Hungarian Ministries of Education (BIO-00042/2000);
Environment & Water (K-36-01-00017/2002, NTE-725/2005)
[4] Darvas, B. et al. (2004) Növényvédelem, 40: 441-449.
[5] Lauber, É. et al. (2006) Abs. 52th Plant Protection Days, 52: 36;
http://www.fvm.hu/doc/upload/200602/ntn_2006_kiadvany_2006_02.pdf
[6] Bálint, A. (1980) A vetomagtermesztés genetikai alapjai.
Mezogazdasági Kiadó, Budapest. 1-171.
[7] Granted by Hungarian Ministries of Education (BIO-00042/2000);
Environment & Water (K-36-01-00017/2002, NTE-725/2005)
[8] Darvas, B. et al. (2005) Abs. 51. Növényvédelmi Tudományos
Napok, 51: 9; http://www.omgk.hu/ntn2005.pdf
[9] Darvas, B. et al. (2006) Abs. 52. Növényvédelmi Tudományos
Napok, 52: 37; http://www.fvm.hu/doc/upload/200602/
ntn_2006_kiadvany_2006_02.pdf
[10] Granted by Hungarian Ministries of Education (BIO-00042/2000);
Environment & Water (K-36-01-00017/2002, NTE-725/2005)