Use of AFLP markers to estimate molecular diversity of Phakopsora pachyrhizi

ROCHA, C. M. L.; VELLICCE, G. R.; GARCÍA, M. G.; PARDO, E. M.; RACEDO, J.; PERERA, M. F.; DE LUCÍA, A. D.; GILLI, J.; BOGADO, N.; BONECARRÉRE, V.; GERMAN, S.; MARCELINO, F. C.; LEDESMA, F.; PLOPER, L. D.; WELIN, B. AND CASTAGNARO, A. P.

ELECTRONIC JOURNAL OF BIOTECHNOLOGY

UNIV CATOLICA DE VALPARAISO

Lugar: Valparaíso; Año: 2015

0717-3458

Good knowledge of the genetic diversityof Phakopsorapachyrhizi, the causal agentof soybean rust (SBR), should be a valuable help when  developing resistance breeding strategies. Forthat reason, an adequate methodology that combines simplesampling with a powerful and reproducible molecular technique could be usefulto assess the genetic diversity of this pathogen. Forthis purpose naturally SBR infected leaves fromcommercial soybean production fields in Argentina, Brazil, Paraguay and Uruguaywere collected in 2008 and 2009. Urediniospores were harvested directly fromlesions and AFLP analysis was performed, generating 1,919 markers, out of which1,488 were found to be polymorphic. The high percentage of polymorphism (77.5%) and the Nei´s genetic diversity coefficient (0.22) togetherindicated high pathogen diversity. Analysis of Molecular Variance showed higher genetic variation within countries than among them,suggesting a high gene flow over large distances. Inaddition, temporal analysis showed ahigher genetic variation within a year than between years. Results wereconfirmed by Cluster and Principal Co-ordinate analysis. Long distancedispersal of urediniospores contributes to relatively low genetic divergence among the countries sampled. This novel method combining a simple collection of urediniospore  with a subsequent analysis by AFLP, gave a good insight into the high genetic diversity of P. pachyrhizi that could explain its rapid ability toovercome single resistance genes in the region.