CONICET | Buscador de Institutos y Recursos Humanos

Background Apomixis is an asexual reproduction process that allows plants to bypass meiosis and fertilization,resulting in clonal seeds that are genetically identical to the maternal genotype. Eragrostis curvula is a grass speciesused as model to disclose the mechanism associated to diplosporous apomixis. Previously, the first E. curvula link-age maps were developed using a F1 population derived from a cross between a sexual female parent (cv. OTA-S)and a facultative apomictic pollen donor (cv. Don Walter). Even though this work allows the identification a markerslinked to apomixis in the male parent, the number of hybrids was not enough to produce a consensus map. Here,a new population is presented, increasing the number of genotyped hybrids to 107 which allows the constructionof a consensus map and the development of KASP markers.Results We constructed a consensus linkage map at the tetraploid level using a mapping population segregatingfor reproductive mode. Within this map, a region associated with apomeiosis (the APO locus) was identified usingmaternal and paternal SNP markers, along with three paternal markers that exhibited strong linkage with the trait.KASP markers were developed, one of which demonstrated 100% concordance with the cytoembryological phe-notype of individuals in both the mapping population and other E. curvula genotypes. Through synteny analysis,the APO locus was mapped onto the E. curvula reference genome, and two genes that could be part of molecularpathways involved in apomeiosis were proposed.Conclusions This study presents the first consensus genetic map and the development of KASP markers for phe-notyping reproductive modes in E. curvula. This map enables the association of the apomixis-determining regionwith molecular markers from both parental genotypes, including the reference sexual tetraploid genotype of the spe-cies (OTA-S). The development and validation of co-dominant molecular KASP markers linked to the APO locus pro-vide a crucial tool for future research and breeding.

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