title: Microsatellite loci for Urochloa decumbens (Stapf) R.D. Webster and cross-amplification in other Urochloa species.
abstract: BACKGROUND
  Forage grasses of the African genus Urochloa (syn. Brachiaria) are the basis of Brazilian beef production, and there is a strong demand for high quality, productive and adapted forage plants. Among the approximately 100 species of the genus Urochloa, Urochloa decumbens is one of the most important tropical forage grasses used for pastures due to several of its agronomic attributes. However, the level of understanding of these attributes and the tools with which to control them at the genetic level are limited, mainly due to the apomixis and ploidy level of this species. In this context, the present study aimed to identify and characterize molecular microsatellite markers of U. decumbens and to evaluate their cross-amplification in other Urochloa species.
  
  
  RESULTS
  Microsatellite loci were isolated from a previously constructed enriched library from one U. decumbens genotype. Specific primers were designed for one hundred thirteen loci, and ninety-three primer pairs successfully amplified microsatellite regions, yielding an average of 4.93 alleles per locus. The polymorphism information content (PIC) values of these loci ranged from 0.26 to 0.85 (average 0.68), and the associated discriminating power (DP) values ranged from 0.22 to 0.97 (average 0.77). Cross-amplification studies demonstrated the potential transferability of these microsatellites to four other Urochloa species. Structure analysis revealed the existence of three distinct groups, providing evidence in the allelic pool that U. decumbens is closely related to Urochloa ruziziensis and Urochloa brizantha. The genetic distance values determined using Jaccard's coefficient ranged from 0.06 to 0.76.
  
  
  CONCLUSIONS
  The microsatellite markers identified in this study are the first set of molecular markers for U. decumbens species. Their availability will facilitate understanding the genetics of this and other Urochloa species and breeding them, and will be useful for germplasm characterization, linkage mapping and marker-assisted selection.
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6010, Campinas, SP, CEP 13083-875, Brazil.
authors.forename: Rebecca C U
authors.initials: RC
authors.lastname: Ferreira
authors.affiliation: EMBRAPA Genetic Resources and Biotechnology, Brazilian Agricultural Research Corporation, CP 02372, Brasília, DF, CEP 70770-900, Brazil.
authors.forename: Letícia J
authors.initials: LJ
authors.lastname: Cançado
authors.affiliation: EMBRAPA Beef Cattle, Brazilian Agricultural Research Corporation, CP 154, Campo Grande, MS, CEP 79002-970, Brazil.
authors.forename: Cacilda B
authors.initials: CB
authors.lastname: do Valle
authors.affiliation: EMBRAPA Beef Cattle, Brazilian Agricultural Research Corporation, CP 154, Campo Grande, MS, CEP 79002-970, Brazil.
authors.forename: Lucimara
authors.initials: L
authors.lastname: Chiari
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6010, Campinas, SP, CEP 13083-875, Brazil. anete@unicamp.br.|Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6109, Campinas, SP, CEP 13083-862, Brazil. anete@unicamp.br.
authors.forename: Anete P
authors.initials: AP
authors.lastname: de Souza
mesh_terms: D056426:Genetic Loci; D005819:Genetic Markers; D018895:Microsatellite Repeats / Q000235:genetics*; D008957:Models, Genetic; D010802:Phylogeny; D006109:Poaceae / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012984:Software
chemical_list: D005819:Genetic Markers
keywords: Enriched library; Forage; Signalgrass; Simple sequence repeat; Transferability