Along with concerns of adverse health effects and loss of biodiversity there are concerns of genetically engineered (GE) crops transferring certain traits to native species through hybridization. In response to this growing concern researching Schafer et al. 2011 conducted systematic roadside surveys looking at the presence and quantity of wild GE crops and non-GE canola populations in North Dakota, where the majority of canola is grown in the United States. The objectives of the study were to document the extension of feral canola populations in the state along with evaluating potential mechanisms of persistence outside of the crop fields. The researchers surveyed a 1×50 m area every 5 miles alongside roughly 3500 miles of road. The sampling was done in early summer before the flowering of the cultivated canola. The testing areas were mapped in relation to transport routes, construction sites, and regions of major canola cultivation. This then was transferred onto a distribution map which showed the different populations of the different herbicide resistant canola populations according to their location and proximity to certain areas. The results concluded the escape of a certain GE canola; Bassica napus was present at almost half of the road survey sampling sites. The authors also discovered a correlation between canola populations along major transport routes and construction sites. Overall their results suggested different means of hybridization into the wild. The results also supported the hypothesis that roadside populations of this plant are unflagging from year to year and have the capability to hybridize in order to produce novel genotypes. ¾Rachel Warburton
Schafer, G.M., Ross, A.A., Londo, P,J., Burdick, A.,C., Lee, H., E., Travers, E.,S., Van de Water, K., P., Sagers, L.,C., 2011. The Establishment of Genetically Engineered Canola Populations in the U.S., PLoS One 10
Canola is generally a variety of rapeseed that contains lower levels of erucic acid which makes it palatable for human consumption, along with reduced levels of toxic glucosin which makes it desirable for livestock feed. Next to soy and maize canola is one of the top produced GE crops in the United States. According to Schafer et al. 2011 genetically engineered plant varieties could influence the population ecology and biodiversity of wild species in either a positive manner, such as by introducing a novel or beneficial trait, or in a negative manner, such as by introducing a destroying gene which could kill off native populations. Currently cultivated canola accounts for 31 mega hectares. Canola cultivars have been engineered for glyphosate and glufosinate, both toxic herbicides, resistance. In 1995 there was an unintentional commercial release of these types of resistant canola and widespread escape was documented from this release. Since then feral canola populations along with non-engineered populations with found biotech traits have been found in Great Britain, France, Australia and Japan. Schafer et al. 2011 saw importance on testing on North Dakota populations of canola since the majority of the canola produced in the U.S. comes from North Dakota.
The sampling was collected with test trips available for testing glyphosate and glufosinate tolerance but there has yet to be a test strip for the third frequently used herbicide, ClearfieldÔ.The GE Brassica napus was present in 45% of the road survey sampling. Among these samplings 86.8% were sexually mature, meaning they were past their seed phase and ranged from flower bug to mature fruit with seeds. This is important to note because it suggests that flowering canola in roadside habitats may have originated from the previous generation’s seeds instead of from seed spill during the current cultivation.
The research also showed that transgenic canola was denser along major transport routes, construction sites and in regions with already high amounts of canola growing. Other feral GE populations were found on access points to crop fields and bridges and roadways, suggesting possible seed spill during transport.
Due to it’s relative newness to domestication of 300¾400 years, Brassica napus, is suspected of contributing to the wild traits because of seed shattering which is fairly common with this plant. One surprise that came out of the study was the growing number of feral populations outside of cultivated areas both near and far from cultivated fields all over North Dakota. Interestingly enough these were found in both habitats with a selection process (roadsides being sprayed with herbicide) and habitats without an obvious selection process.
Overall the results suggest a number of ways canola plants may be introduced to the wild in the future. They suggest that canola may colonize seed repositories in fill dirt and consequentially establish a soil seed bank, which refers to the natural and usually dominant, storage of seeds within the soil of certain ecosystems. In general Schafer et al. 2011 came to the conclusion that field and feral populations originated from different sources due to their different spacing of growing times. The research team also suggest hybridization could have occurred via pollen flow between fields of transgenic canola varieties. It is more difficult to verify hybridization without being able to test on the third herbicide, ClearfieldÔ.
The results support the hypothesis that there is variation from year to year with the feral canola populations. To conclude, Schafer et al. 2011 suggest that in order to ensure global food security researchers, regulatory agencies and industry must take full advantage of the tools that biotechnology provides.