TITLE:
Development, Validation and Characterization of Genic Microsatellite Markers in Urochloa Species
AUTHORS:
Juliana Santos Souza, Lucimara Chiari, Rosangela Maria Simeão, Mariane de Mendonça Vilela, Leonardo Rippel Salgado
KEYWORDS:
Brachiaria, Signalgrass, Simple Sequence Repeat, Transferability, Tropical Forage
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.2,
January
26,
2018
ABSTRACT: Urochloa (syn. Brachiaria) cultivars
represent 85% of tropical pastures occupying 114 million hectares of cultivated
grasslands in Brazil. Despite the commercial importance of the Urochloa species, low molecular
information is available and is far from saturating the genome. Investigating
and obtaining more markers associated to characteristics of difficult and late
expression can benefit in accelerating breeding programs of more important
species. Aiming to increase the number of molecular markers, genic
microsatellite markers were obtained from transcriptome of U. decumbens and analyzed for their cross-amplification to U. brizantha, U. humidicola and U.
ruziziensis. Genic microsatellite markers were isolated from a
transcriptome obtained of U. decumbens “Basilisk” roots. Specific primers were
designed for one hundred loci, and 32 were polymorphic presenting polymorphism
informative content values ranging of 0.12 to 0.81 (mean 0.54). Amplified
microsatellite regions yield an average of
4.44 alleles per locus (ranging of 1 to 13). Cross-amplification to U. brizantha, U. humidicola and U.
ruziziensis were successfully performed, although the number of the loci
transferred varied among them. Multiple Correspondence Analysis revealed three
distinct groups separating accessions and species. Four genetic markers
presented high potential to distinguish sexual and apomictic accessions of Urochloa and must be further
investigated. The genic markers identified in this study are the first set of
expressed sequence tagged molecular markers for Urochloa species.