High genetic diversity of Mycospaherella graminicola (Zymoseptoria tritici) from a single wheat field in Tunisia as revealed by SSR markers
Samia Berraies, Mohamed Salah Gharbi, François Belzile, Amor Yahyaoui, Mohamed Rebah Hajlaoui, Mokhtar Trifi, Martine Jean and Salah Rezgui
Microsatellite markers were used to assess genetic diversity of Mycosphaerella graminicola at a micro geographical scale in Tunisia. Forty five (45) isolates were sampled and assessed using seven pairs of single-locus microsatellite primers not previously tested on populations of M. graminicola in Tunisia. Genetic diversity of the field population ranged from 0.403 to 0.555 with an average of 0.484. A high level of genetic diversity was found at a sharp scale throughout the pathogen population tested. Among 45 isolates sampled, 39 different multi locus genotypes (MLG) were identified. Cluster analysis (UPGMA) showed that 86% of the isolates tested were distinct. The high degree of DNA polymorphism, the large number of different molecular genotypes and the pattern of cluster analysis suggest that sexual ascospores and/or asexual spores of a highly mutable local population could have contributed to the genetic diversity of M. graminicola in Tunisia.