Identification and characterization of microsatellites in isolates of Peronospora tabacina collected in tobaccoproducing states of Mexico

Abstract

Peronospora tabacina is considered the main limiting factor in tobacco production worldwide. In Mexico, information on the genetic diversity of this pathogen is scarce; therefore, the objective of this research was to evaluate 12 microsatellites in 20 isolates collected in the states of Nayarit, Chiapas, and Veracruz. PCR amplification and sequencing of these microsatellites were performed; as well as the alignment and comparison of the sequences deposited in the GenBank database. A total of 19 isolates showed amplification for the 12 microsatellites evaluated, while in one of the isolates, the amplification of two microsatellites was not observed, it being possible to determine that P. tabacina isolates present in Nayarit, Chiapas, and Veracruz are genetically homogeneous. Regions of dinucleotides were observed, most corresponding to (GT)n repeat motifs or (TG)n variations, as well as (AC)n, (CA)n, (AT)n and (AG)n motifs. The isolates analyzed in this study can be considered products of clonal lines, therefore no genetic diversity was found in these isolates.