EXTRACT: Ortiz, a breeder of several crops including cassava, had been sceptical when SciDev.Net asked him for an independent comment about this study in 2011, saying that the genetic material of wild and native cassava varieties should be further studied for cassava biofortification, instead of using genetic modification.
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GM cassava study retracted over 'missing' data
Zoraida Portillo
SciDev.Net, 26 September 2012
http://www.scidev.net/en/agriculture-and-environment/gm-crops/news/gm-cassava-study-retracted-over-missing-data.html

[Lima] A study that last year claimed to have found a way to boost the protein content of a staple crop rich in energy but poor in protein has been retracted after researchers failed to find any supporting data to back up its claims.

The study, published in PLoS ONE in January 2011, has been cited at least five times.

The authors claimed to have created a genetically modified (GM) cassava crop that expressed a gene called zeolin, thereby increasing the protein content by 12.5 per cent and potentially allowing the plant to become "capable of supplying inexpensive, plant-based proteins for food, feed and industrial applications".

But the study was retracted this month after the authors were unable to find the zeolin gene in plants from subsequent studies. The retraction notice says that "an institutional investigation revealed that significant amounts of data and supporting documentation that were claimed to be produced by the first author could not be found" and "the validity of the results could not be verified".

Cassava is a staple food in many developing countries, but its nutritional content especially in protein and micronutrients is low, something that the researchers from the Laboratory for Tropical Agricultural Biotechnology at the Donald Danforth Plant Science Center in the United States and Mayaguez University in Puerto Rico said they were on the verge of overcoming with the GM cassava.

The lead author of the article, Mohammad Abhary, left the Danforth Center in the middle of 2011, and the corresponding author Claude Fauquetdid not respond to SciDev.Net's requests for comment.

In a statement to Retraction Watch blog, Danforth president James Carrington, admitted that questions arose shortly after the paper was published, when the researchers tried to extend the findings.

Carrington said a more systematic analysis "indicated that the materials published in the paper were not as described, and that the materials that were described could not be found".

Rodomiro Ortiz, professor of plant breeding and biotechnology at the Swedish University of Agricultural Sciences, told SciDev.Net that the case confirms the need not only for rigor in initial research, but for experiments to be repeated before publication.

"It's unfortunate to come to this situation but [retraction] was necessary to keep the ethical values of scientific research," he added.

Ortiz, a breeder of several crops including cassava, had been sceptical when SciDev.Net asked him for an independent comment about this study in 2011, saying that the genetic material of wild and native cassava varieties should be further studied for cassava biofortification, instead of using genetic modification.
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Comment by Nagib Nassar, Universidade Brasilia, Brasil ( Brazil )
1 October 2012 [changes made to spelling etc. to clarify English] 
Wild Manihot species as a safe source of protein should have been exploited before looking to another unsafe source in virus or bacteria and trying to transfer it by molecular means. So much successful work has been done on this subject by this author and his associates at the Universidade de Brasilia, through very low expense projects supported by the Brazilian National Council of Research Development- CNPq, Brasilia and the Canadian International Research Development Center – IDRC. Not only protein rich hybrids were obtained, but essential amino acids which do not occur in common cassava were reached. See for example this article published some five years ago in Genetics and Molecular Research: Amino acid profile in cassava and its interspecific hybrid by Nagib M.A. Nassar1 and M.V. Sousa2 
1Departamento de Genética e Morfologia, 2Departamento de Biologia Celular, 
Universidade de Brasília, Brasília, DF, Brasil 
Corresponding author: Nagib M.A. Nassar 
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Genet. Mol. Res. 6 (2): 292-297 (2007) 
The first publication on transferring high protein content from the wild was in 1982 (thirty years ago) by Nassar and Dorea in Turrialba as follows: Protein content of cassava cultivars and its hybrid with wild Manihot species
NMA Nassar, JG Dorea – Turrialba, 1982. The case of Wild Cassava rich in protein was documented in several publications in the decade 1970 by Nassar and co workers. For example publication in the leading Suisse Journal Experientia in 1977 as follows : NASSAR, NM A. and COSTA, C. 1977. Tuber formation and protein content in some wild
Manihot species native of Central Brazil. Experientia (Basel) 33: I304- I305