GM Free Cymru

Production and decomposition of DK-440 BTY corn[1]-[2]

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.

Production and decomposition of DK-440 BTY corn[1]-[2]

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.


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; id=41771 [2] Székács, A. et al. (2006) Abs. 52th Hungarian Plant Protection Days, 52: 32; 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; [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; [9] Darvas, B. et al. (2006) Abs. 52. Növényvédelmi Tudományos Napok, 52: 37; 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)