Maize landraces from Northern Argentina: genetic clusters and ecological niches

DOMINGUEZ PIA GUADALUPE; GUTIERREZ, ANGELA; VERA PABLO; DEFACIO RAQUEL; PUEBLA ANDREA; PANIEGO NORMA; LIA VERONICA VIVIANA

Simposio; Conservation Genomics at the Population Level Conference; 2022

Wellcome Connecting Science

Maize landraces are a strategic resource as a source of original alleles to face the current agriculture challenges. In Argentina, maize landraces are associated with aboriginal traditional farming systems, and their existence is at the present time being threatened by the introduction of commercial varieties bearing higher productivity and by the growing urbanization of communities. Previous studies of landraces from Northern Argentina through microsatellite molecular markers indicated that they have high genetic variability and a clear structuring between two regions of the country: the Northwest and the Northeast (Bracco et al. 2016; Rivas et al. 2022). In the present work, we use double digest restriction‐site‐associated DNA (ddRAD) sequencing to further explore the population structure of these landraces. Fifty individuals were evaluated while 5275 SNPs were obtained. The results indicate that there are three main genetic groups: i-High-altitude maize from the Northwest, ii-Popcorns from the Northwest and, iii-Low-altitude maize from the Northeast and the Northwest. The integration of our SNP matrix with a maize landrace SNP panel representing the racial diversity of the Americas (Kistler et al. 2018) shows that the groups retrieved in this study belong to the Andean maize, North American maize and Tropical Lowland maize clusters of Kistler et al., respectively. A maximum entropy modelling of the ecological niches and distributions of these groups suggests a potential distribution of Andean maize in the Mexican and African highlands, of the Tropical Lowland maize in practically the entire tropical region of the globe, and of North American maize at moderate altitudes in all continents. Modelling potential distributions in two future climate scenarios (CNRM-CM6-1 and MRI-ESM2-0; Voldoire et al. 2019, Yukimoto et al. 2019) suggests that the distributions of the Andean and Tropical Lowland landraces will be strongly undermined, but not those of North American landraces. Integrating genomic data and distribution models of these landraces will allow directing future conservation efforts in the face of climate change.