A data mining approach gives insights of causes related to the ongoing transgene presence in Mexican native maize populations

Mexico is the center of origin of maize and one of the phenomena that imperil maize conservation is transgene presence. Although previous studies have documented transgene presence in Mexican landraces, to date there is no countrywide transgene monitoring protocol, nor systematic analyses assessing which factors could be related with transgene presence and dispersal. In this work, we propose a geographically representative sampling protocol and present empirical data from three sampled states: Mexico City, Oaxaca and Chiapas. To further investigate which environmental and social variables could be associated with transgene presence, we carried out a data mining approach. To assess transgene presence in collected maize samples, we used Real-Time PCR, finding that transgenes were widely distributed across sampled localities: 33% of the localities in Chiapas, 25% in Mexico City and 11% in Oaxaca. The data mining approach allowed us to identify state-specific spatial associations in Chiapas and Oaxaca. In Chiapas, a higher probability of transgene presence appeared related to the coexistence of industrialized maize agriculture, while in Oaxaca it was related with seed exchange. We discuss the importance of implementing a national biomonitoring protocol to increase our understanding of the sources that enable transgene presence and dispersal.

Automated summary

Mexico is one of the origins of maize, and transgene presence poses a threat to maize conservation. Despite previous studies confirming the presence of transgenes in Mexican landraces, there is currently no nationwide transgene monitoring protocol, nor systematic analyses on factors related to transgene presence and dispersal. This study proposes a geographically representative sampling protocol and presents empirical data from three states in Mexico. Real-Time PCR is used to assess transgene presence in collected maize samples, and the results show widespread distribution of transgenes across the sampled localities. The data mining approach identifies state-specific spatial associations related to transgene presence. The study emphasizes the importance of implementing a national biomonitoring protocol to increase understanding of the sources that enable transgene presence and dispersal.