Genome size in eight diploid Paspalum L. species

REUTEMANN, AV; ECKERS, F; DAVIÑA, JR; MARTINEZ, EJ; RUA, GH; HOJSGAARD, DH; HONFI, AI

Congreso; XXII Congreso Internacional de Genética; 2018

Sociedad Brasilera de Genetica, International Genetic Federation & Sociedad Argentina de Genética

Karyotype total length and DNA absolute content are two ways to analyze genome size focusing in chromosome constitution and whole DNA volume. Chromosome idiograms represents structural arrangement of DNA, genetic information of each chromosome is understood as linkage group and absolute DNA content is a measure of genome size. However, relationships between karyotypes and genome size are not good understood in several species. The aim of this work was to analyze the relationship between the genome size and karyotype features. Chromosome analysis were made by classical staining and DNA content estimation by flow cytometry using propidium iodide for staining and Zea mays CE-777 was used as standard. Two karyotype formulae, 20m (P. lilloi, P. indecorum, P. jurgensii, P. paniculatum, P. umbrosum) or 18m+2sm (P. quarinii, P. paucifolium, P. falcatum) were found. All Paspalum diploid species (2n=2x=20) have unimodal, highly symetric karyotypes, composed by small metacentric and submetacentric chromosomes, but species differ by total chromosome length (TCL). Genome size vary between species, since small genomes with 0.709 pg per monoploid nucleus content (Cx) in P. umbrosum (TCL= 30.9μm), 0.804 pg/Cx in P. indecorum (TCL= 29.6μm), and P. lilloi (TCL= 45,4μm), to 0.933 pg and 1.005 pg/Cx in P. paucifolium (TCL= 43.2μm), and P. falcatum (TCL= 37.5μm), respectively. Also, P. paucifolium and P. falcatum, have no significative differences in 1Cx-value (p>0.05), and P. indecorum regarding to P. lilloi. Otherwise, DNA content 1Cx-value increases when TCL increases, in all species. Karyotype total length and DNA monoploid content behave coordinately upsize.