Genetic differentiation in Pyrenophora teres f. teres populations from Syria and Tunisia as assessed by AFLP markers
To investigate the level of genetic differentiation and diversity among
Pyrenophora teres isolate populations originating from different agro-ecological
areas of Syria and Tunisia and to determine the potential of AFLP profiling in
genotyping Pyrenophora teres f. teres. In this study, AFLP markers have been
employed to identify patterns of population structure in 20 Pyrenophora teres f.
teres populations from Syria and Tunisia. Ninety-four isolates were studied by
the use of a protocol that involved stringent PCR amplification of fragments
derived from digestion of genomic DNA with restriction enzymes EcoRI and
MesI. Based on 401 amplified polymorphic DNA markers (AFLP), variance
analyses indicated that most of the variation was partitioned within rather than
between populations. Genotypic diversity (GD) was high for populations from
Rihane, local landraces and different agro-ecological zones (GD = 075–086).
There was high genetic differentiation among pathogen populations from
different host populations in Syria (Gst = 031, ht = 0190) and Tunisia
(Gst = 039, ht = 0263), which may be partly explained by the low gene flow
around the areas sampled. A phenetic tree revealed three groups with high
bootstrap values (55, 68, 76) and reflected the grouping of isolates based on
host, or agro-ecological areas. AFLP profiling is an effective method for typing
the genetically diverse pathogen Pyrenophora teres f. teres.