CONSTRUCTION OF A GENETIC LINKAGE MAP OF DIPLOID Paspalum rufum AND IDENTIFICATION OF GENOMIC REGIONS ASSOCIATED WITH APOSPORY EXPRESSIVITYfum

JULIANA STEIN; JUAN PABLO A. ORTIZ; MARIKA, BOCCINI; EMIDIO, ALBERTINI; MARIANO, SOLIMAN; LUCAS, DEMARCHI; LUCIANA, DELGADO

Mendoza

Congreso; XVII CONGRESO LATINOAMERICANO DE GENÉTICA XLVII CONGRESO ARGENTINO DE GENÉTICA; 2019

Sociedad Argentina de Genética, Asociación Latinoamericana de Genética, etc

Apomixis is an asexual reproduction by seedsstrongly linked to polyploidy. Genetic analysis oftetraploid cytotype of Paspalum spp. showed thatthe trait is inherited as a single dominant locuswith strong repression in recombination. However,natural diploid populations of Paspalum rufumproduce aposporous embryo sacs (AES) in differentproportions. These individuals are able to overcomethe dependence between polyploidy and apomixisand are key material to understand apomicticpathway regulation. The objectives of this work areto build a genetic linkage map of the species andidentify markers related to apospory expressivity.A segregating population of 87 individuals was usedfor linkage analysis. Segregation of AFLP markerswas analyzed with JoinMap 4.0. Quantification of AESwas carried out by cytoembryological observationsof ovules at anthesis. Single-point analysis (SPA)was performed to identify regions associated withapospory (R2> 0.15). The maternal map consisted of254 markers distributed on 20 linkage groups (LG)over a total genetic distance of 1,672.5 cM, while thepaternal map contained 216 loci grouped on 20 LGalong 1,185.8 cM. SPA showed 11 loci associated toapospory expressivity in the maternal map and 3 inthe paternal map. Most of the markers were locatedin three LG of both parental genotypes. This studyprovides the first genetic linkage map of diploidP. rufum with gametophytic apomixis capacity.Furthermore, regression analysis suggests thatapospory expressivity is influenced by more thanone genomic region.