Bt brinjal too can create super weeds.


Bt brinjal too can create super weeds. 

Gene flow from a transgenic plants has remained a contentious issue. In the absence of experimental data, the task to pinpoint exactly as to how much is the potential risk, especially in centres of diversity, becomes daunting. The GM industry has often used lack of experimental data to show there is no cause for concern. It has happened in India, in the case of Bt cotton, and more recently when the moratorium on Bt brinjal came in 2010.

John Samuels of the Novel Solanaceae Crops Project, Penzance, Cornwall, UK, has raised some valid concerns, based on available data, in an excellent paper published in Trends in Biotechnology (Vol 31, Issue 6, June 2013). Admitting that transgene flow from Bt brinjal to wild, weedy and cultivated relatives is a major biosafety concern, he writes in an article Transgene Flow from Bt Brinjal: a real Risk? (URL: http://www.cell.com/trends/biotechnology/fulltext/S0167-7799(13)00068-1): "in preliminary risk assessment tests in India in 2007, only four spiny species were tested for interfertility with S.melongena  (http://www.envfor.nic.in/divisions/csurv/geac/bt_brinjal.html). They found only Solanum incanumL. (the nearest wild relative of brinjal) to be crossable; however, the production of hybrid progeny was not investigated." With such limited scientific studies available, obviously gene flow was considered to be not much of a problem. 

Citing various reasons like inadequate experimental methodologies and erroneous nomenclature of the parent species, John Samuel tells us that the biosafety implications of hybridisation remained compromised. Looking through the research data now available, he says that six wild relative species and four cultivated species have the potential to crossbred with the transgenic Bt brinjal. I have taken this table out from the article for an easy understanding. 

Table 1 Solanum species of India known to cross with brinjal 
SpeciesCommon nameStatus
S. aethiopicum L.Scarlet eggplantCultivated
S. cumingii DunalWild brinjalWild
S. incanum L.Bitter tomatoWild
S. insanum L.Weedy brinjalWild
S. macrocarpon L.Gboma eggplantCultivated
S. marginatum L.f.White-margined nightshadeWild/introduced
S. ovigerum DunalBrinjal landracesCultivated
S. torvum Sw.Pea eggplantSometimes cultivated/introduced
S. violaceum OrtegaIndian nightshadeWild
S. virginianum L.Bitter brinjalWild
  
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His conclusion: "Furthermore, the risk assessment of pollen-mediated transgene flow from Bt brinjal, if cultivated in Bangladesh or the Philippines, should not rely on the inadequate, previously undertaken ERA (Environmental Risk Assessment) tests." Hope the scientists as well as the science administrators are listening. Especially in the light of latest revelations that show how super weeds are becoming a nuisance in United States and Canada. 

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