Transference of wheat expressed sequence tag-simple sequence repeats to Paspalum species and cross-species amplification of Paspalum notatum simple sequence repeats: potential use in phylogenetic analysis and mapping.

摘要

The genus Paspalum L. includes numerous species of agronomic importance. The objectives of this work were to evaluate the transferability and polymorphism of publicly available wheat (Triticum aestivum L.) expressed sequence tag (EST)-simple sequence repeat (SSR) (wEST-SSR) markers to Paspalum spp., assess the cross-species amplification of Paspalum notatum Flugge genomic SSRs (PnSSRs) within the genus, and evaluate both types of markers for phylogenetic analyses and mapping. Thirty-two accessions including 10 species were used. Moreover, 65 F₁ hybrids of P. notatum were used for mapping. Transferability ratio of wEST-SSRs was 72.72%. On average 19.25 bands per primer combination were obtained. Cross-species amplification of PnSSRs was 55.37%, with an average of 9.45 fragments per primer pair. Both types of markers differed in the amplification capacity between primers pairs and species. Clustering analysis with wEST-SSR data discriminated accessions by species and taxonomic groups. Genomic relationships were in agreement with previous works indicating that wEST-SSRs are adequate for phylogenetic surveys in the genus. Mapping experiments showed that both wEST-SSRs and PnSSRs mapped scattered in the genome. One hundred two new markers were added to the existent P. notatum linkage groups. Primer pairs ksum206, ksum219, and PN03 F2 generated markers linked to apospory. Sequences of EST-SSRs experimentally mapped in P. notatum showed 46.23 to 55.27% similarity with the original wheat EST. A preliminary comparative mapping analysis was carried combining experimental and in silico mapping results.