Occurrence and maintenance of non-commercially cultivated Gossypium in Pará, Brazil

Abstract The state of Pará contains cotton populations ( Gossypium spp.) maintained primarily in household environments for medicinal purposes. The coexistence of these materials with the commercial cultivation of genetically modified (GM) cotton raises concerns regarding the potential impacts of gene flow on the conservation of Gossypium genetic resources. This study evaluated the morphological variability of cotton plants maintained outside commercial cultivation in the state of Pará and assessed evidence of potential transgenic introgression under current field conditions. Field expeditions were conducted in 2025 and complemented by documentary analyses, morphological characterization, and tests for the detection of transgenic proteins. A total of 686 Gossypium occurrence sites were recorded, all associated with anthropogenic environments. Populations of Gossypium barbadense L. and Gossypium hirsutum L., including the “Verdão” cotton type, were identified, as well as rare individuals with intermediate morphological characteristics consistent with putative interspecific hybridization. No G. barbadense or “Verdão” cotton plant tested positive for transgenic proteins. Likewise, no transgenic proteins were detected in seeds collected from plants located near GM cotton fields. Under the conditions evaluated, the findings did not indicate widespread transgenic introgression and establish an important baseline for monitoring future changes in these traditional cotton populations, including those potentially associated with the expansion of commercial GM cotton cultivation and the long-term effects of cultural erosion.