Insights from Genetic Studies: SNP Analyses Confirm White Clover Naturalization in Brazil

Abstract

White clover (Trifolium repens) is a stoloniferous legume herb native to Eurasia, which had been introduced and spread globally. In Brazil, it was introduced as forage crop. While previous studies focused mainly on its agricultural benefits, much remains unclear about its territorial dynamics, introduction process and potential threats in Brazil. This study aims to estimate the genetic diversity of naturalized white clover populations in Brazil and assess the influence of cultivars into these populations diversity. Through MIG-Seq analysis, 1097 SNPs show that Brazilian populations have 94% within-population variation. Additionally, two mountainous areas clustered together, while rural and urban areas formed a second cluster. Cultivars are less diverse and have 27% of their genetic variability between them. We found that some populations admixture with cultivated varieties, while more isolated mountainous populations were singular in their genetic background. We can conclude that it is possible that parts of the populations are originally native, brought during European immigration, while others appear to have similar cultivar ancestry, indicating possible biological escapes from cultivars into naturalized populations. Considering ecological data and our genetic findings, it is confirmed that white clover is indeed naturalized in Brazil.