The Eragrostis curvulacomplex has a basic chromosome number of × = 10 and includes cytotypes with different ploidy levels (2x – 8x). Diploid plants reproduce sexually while higher ploidy levels plants reproduce by pseudogamous diplosporous apomixis. Our results indicate that apomeiosis in this species is controlled by a single hemizygous genomic region (APO-locus) located in one of the two sub-genomes of the species (subgenome A) having an extension of approximately 24Mbp on linkage group 9 of the apomictic Don Walter´s map, delimited by three co-segregating markers. The comparison of the region delimited by these markers between sexual and apomictic genomes of the species showed a poor level of synteny, having an extension of approximately 11 Mbp in the sexual genotype. The Eragrostis curvula APO-locuscontains 485 genes that are grouped in “islands” surrounded by long arrays of tandem repeats (Satellite DNAs) associated to the centromere region. One hundred and forty-three (143) of these genes show homology with genes present in the homoeologous 9B chromosome and 81 genes are exclusively present in the APOlocus of seven apomictic genotypes. They are expressed in different plant tissues and organs. Some of these APO genes were also captured by pistils transcriptomics analysis and PCR, corroborating their absence in sexual genotypes. It was also observed that some transcripts show differential splicing depending on whether the gene is located in the Apo locus(Chrom. 9A) or in the corresponding region on the homoeologous 9B chromosome. Many of the genes present in the region show mutations or short versions compared with the homoeologous version on 9B; many of these genes are regulatory genes and have no homology with any known gene, and other genes seem not to have any role in reproduction. A reverse genetic approach is being followed to functionally characterize these genes.

Fil: Gallo, Cristian Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentina

Fil: Echenique, Carmen Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentina

Fil: Zappacosta, Diego Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentina

Fil: Selva, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentina

Fil: Carballo, José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina

Fil: Bongiorno, Giacomo. Universita Degli Studi Di Perugia. Department Of Agricultural, Food And Environmental Sciences;

Fil: Albertini, Emidio. Universita Degli Studi Di Perugia. Department Of Agricultural, Food And Environmental Sciences;

Fil: Cáccamo, Mario José. National Institute Of Agricultural Botany. East Malling Research Station.; Reino Unido

Fil: Surbanovski, Nada. National Institute Of Agricultural Botany. East Malling Research Station.; Reino Unido