Conservación de variedades criollas de maíz y coexistencia con transgénicos

Maize (Zea mays L.) is a widely cultivated crop in Uruguay and boasts a high degree of genetic diversity, represented by landraces conserved ex situ and in situ – on farm by family farmers. Since 2003, with the introduction of the transgenic maize variety MON810, the use of genetically modified cultivars has become widespread throughout the country. Due to the reproductive characteristics of the species, commercial cultivars can transfer their transgenic characteristics to native varieties through cross-pollination, which poses a problem for in situ - on farm conservation. In this context, the objective of this work is to characterize the levels of transgenic DNA contamination in a collection of landraces conserved in Uruguay and to generate inputs for establishing strategies that promote coexistence between transgenic crops and native varieties. Information corresponding to 54 landraces and 33 farmers was analyzed and integrated. This information came from ethnobotanical surveys conducted through semi-structured interviews, phenotypic characterizations of ear and grain, and the presence/absence of transgenic DNA using DAS-ELISA. Fisher's exact test was used to determine the association between the detection of transgenic DNA and ethnobotanical and phenotypic characteristics present in the database. A multiple correspondence analysis (MCA) was performed to graphically visualize the existence or absence of relationships between the variables analyzed as a whole and the presence of transgenic DNA, using the R 3.6.0+ program in conjunction with the “readr” “FactoMineR” and “factoextra” packages. Of the total varieties analyzed (54), 21 obtained a positive transgenic DNA detection result (38%), corresponding to 15 of the producers interviewed, from all the represented regions of the country. Differences were detected according to the primary use; varieties intended for self-consumption had positive detections less frequently than those intended for animal feed. Producers who participate in organizations had positive detections in their varieties less frequently than those who reported no ties to any producer organization. It is necessary to promote the flow of relevant information for in situ-on farm conservation of the genetic diversity of maize crops, improve access to transgenic DNA detection tools, and generate a regulatory framework that helps promote regulated coexistence between production systems that use transgenic cultivars and native varieties.