Molecular caracterization of trhee cycles of phenotypic reccurent selection with microsatellites and SRAPs markers.

REOLON-COSTA, A.; MARTIN, E.; GRANDO, M.F.; CRAVERO, V

Rosario

Simposio; IX International Symposium on Artichoke, Cardoon and their wild relatives; 2015

ISHS

The objective of this work was to evaluate the impact of two cycles of phenotypic recurrent selection over the allele frequencies and genetic variability in an artichoke population using two types of DNA molecular markers. The genomic DNA was extracted using a DNeasy Plant mini Kit (Qiagen), from young leaves collected randomly from 30 plants in each cycle populations (C0, C1 e C2). The DNA was quantified by electrophoresis in agarose gel (1%) and diluted in sterile water when it was necessary. All plants were characterized using 15 microsatellites (SSRs) and seven Sequence-Related Amplified Polymorphisms (SRAPs) combinations. The amplicons were separated by electrophoresis in denaturing polyacrylamide gels (6%) and visualized by silver staining. The percentage of polymorphic loci, allele?s frequencies, number of alleles per locus, number of effective alleles, observed and expected heterozygosis, coefficient inbreeding (FIS, FIT e FST) and index of genetic identity were calculated. Also, a molecular variance analysis (AMOVA) was performed. Four of the 15 microsatellites tested, showed polymorphisms between the three populations (C0, C1 and C2). From the seven SRAPs combination tested, three showed amplification in all cycle populations generating 61 loci. The percentage of polymorphic loci varied between cycles. The values of observed heterozygosis for the SSRs indicate that there was not reduction of genetic variability thought the two cycles of phenotypic recurrent selection. This is also evidenced by the negative values obtained for FIS and FIT. SRAPs are dominant markers, so, only expected heterozygosis values were calculated. Molecular variance analysis performed with both kind of markers (SRAP and SSR) showed that there was greater variation within each cycle population than between them. This results show that the phenotypic recurrent selection applied provoked changes on the allele?s frequencies but no generated reduction of the genetic variability throughout the different cycles.