02253naa a2200253 a 450000100080000000500110000800800410001902400350006010000200009524501090011526000090022452015150023365000230174865300170177165300220178865300140181065300280182470000190185270000210187170000200189270000180191270000170193077300520194718952732022-07-27       2011    bl uuuu     u00u1 u    #d7 a10.1007/s12042-011-9078-12DOI1 aVIGNA, B. B. Z.  aGenetic diversity and population structure of the Brachiaria brizantha germplasm.h[electronic resource]  c2011  aBrachiaria brizantha (Hochst. ex A. Rich.) Stapf. (syn. Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster) is a species used primarily as forage in tropical America and Southeast Asia. B. brizantha has been extensively researched since the 1980s with the initiation of the Tropical Forages Breeding Program conducted by the Brazilian Agricultural Research Corporation (Empresa Brasileira de Pesquisa Agropecuária; EMBRAPA), holding one of the largest germplasm collections in the world. This work has identified 15 new microsatellite markers for this species, which have been used in addition to five previously reported markers, to estimate the genetic similarities among 172 accessions and six cultivars of this species. Similarity index values ranged from 0.40 to 1.00. Two duplications were found in the germplasm. A Bayesian analysis performed using the STRUCTURE 2.3.3 program revealed the presence of three clusters with different allelic pools. This analysis is valuable for the performance of crosses to explore heterosis; however, the mode of reproduction of the accessions and ploidy barriers must be observed for effective exploration. A grouping analysis using the neighbor-joining method was consistent with the STRUCTURE analysis, and a combination approach suggested that this germplasm collection does not exhibit considerable genetic variability despite the presence of three distinct allelic pools. The lack of correlation between the genetic and geographic distances is also discussed.  aUrochloa brizantha  aForage grass  aMolecular markers  aPolyploid  aSimple sequence repeats1 aCANCADO, L. J.1 aFRANCISCO, P. M.1 aVALLE, C. B. do1 aZUCCHI, M. I.1 aSOUZA, A. P.  tTropical Plant Biologygv. 4, p. 157-169, 2011.