Two-Year Monitoring of Ruderal Rapeseed Populations in Areas Potentially Contaminated with Genetically Modified Plants and Country-Wide Pollen Sample Screening for GMO Contamination in Latvia

Abstract

Latvia has documented cases of unintentional release of genetically modified plants (GMP), including contamination of rapeseed with GM varieties such as GT73. Due to significant import and export of rapeseed (over 120 thousand tons annually from 2020 to 2022), monitoring is essential to evaluate accidental GMP spread in the environment. Similar studies in Germany, Switzerland, the Netherlands, and Lithuania have been conducted to monitor GM rapeseed near processing plants, ports, and transport routes, generally finding minimal or no GM contamination in ruderal populations. By using bees as natural pollen collectors, pollen sampling serves as an indicator of GMO presence and spread while also providing insight into gene-flow risks within terrestrial ecosystems. Given Latvia’s recent detection of accidental GM rapeseed admixtures and limited annual testing, this study prioritised pollen analysis and monitoring of ruderal rapeseed plants. This study presents a comprehensive two-year monitoring effort of ruderal rapeseed populations in Latvia, focusing on potential contamination with GMPs near ports, railway cargo areas, and rape-seed processing factories. It also includes a nationwide screening of pollen samples to detect GMP presence, aiming to assess the environmental impact and spread of GMP in Latvia. None of the samples were considered to contain GMP screening elements.