Influence of Abiotic and Biotic Environment on the Ecological Performance of GM and non-GM Wheat

Background

This project assesses the influence of environmental variation on the ecological behavior of wheat which has been genetically modified (GM) for disease-resistance traits (7 lines) in relation to non-modified wheat (5 sister lines of the GM lines and 4 other varieties). We test if GM traits have negative or positive fitness effects in different experimental environments such as low and elevated soil nitrogen or different competitive backgrounds.

Methods

In 2007, the 16 lines have been ecologically characterized and propagated in glasshouse environments with varying nutrient level but excluding pathogens. In 2008, the offspring were grown as "phytometers" in field plots according to a full mechanistic diallel design (each phytometer line occurring in each line as competitive background). In addition to the 16 wheat backgrounds there were backgrounds of two other crop species and two weed mixtures to assess the competitive behavior of the GM and non-GM lines outside their own crop. One subplot within each plot did not receive nitrogen fertilizer whereas a second subplot had the same nitrogen level as the rest of the plot. The field experiment was repeated in 2009 with additional environmental treatments (plots with line mixtures, presence/absence of pathogenic fungi).

We assessed eco-physiological traits, growth, biomass allocation and reproductive traits. In addition, the phytometer plants were used to measure potential gene flow from and to GM and non-GM wheat lines, using the phytometer x competitive background design as an equivalent to a genetic diallel, and to assess maternal carry-over effects.

Our results demonstrate that the phytometer approach can be used as cost-efficient and low-risk method to assess both the influence of the environment on GM plants and of GM plants on their conspecifics. Because the measured traits are related to agronomic productivity and ecological performance, a wide range of potential benefits and hazards (including gene flow and recombination) can be assessed. As a side issue this project also monitors potential ecological carry-over effects on the environment of GM and non-GM lines after harvest.

Participants

Prof. Dr. Bernhard Schmid (Project Leader)
Olena Kalinina (Ph.D.)
Simon Zeller (Ph.D.)
Simone Nägeli (M.Sc.)
Silvan Rieben (M.Sc.)

Co-operation partners

Prof. Dr. Beat Keller, Institute of Plant Biology, University Zurich

Publications

Kalinina, O., Zeller, S. L., Schmid, B. (2011). Competitive performance of transgenic wheat resistant to powdery mildew. PLoS One 6(11): e28091 (11 pages).

Rieben, M., Zeller, S. L., Kalinina, O., Schmid, B. (2011). Gene flow in genetically modified wheat. PLoS One 6(12): e29730 (7 pages).

Zeller, S.L., Kalinina, O., Brunner, S., Keller, B., Schmid, B. (2010). Transgene x environment interactions in genetically modified wheat. PLoS ONE, 5(7): e11405.

Zeller, S.L., Kalinina, O., Flynn, D.F.B., Schmid, B. (2012). Mixtures of genetically modified wheat lines outperform monocultures. Ecological Applications 22: 1817-1826.