DEVELOPMENT OF DI- AND TETRANUCLEOTIDE REPEAT PRIMER FOR DISCRIMINATION OF FUSARIUM SPECIES

ABSTRACT The genetic diversity profiles of 19 isolates of the fungal pathogen Fusarium species, 14 from Egypt and 5 from Germany, were analyzed based on morphological characteristics and microsatellite markers. Five microsatellites were selected and primers were designed. Microsatellite‐primed polymerase chain reaction using the dinucleotide and tetranucleotide primers showed clear polymorphisms among the different Fusarium spp. isolates. Both primers gave similar results in phenetic analysis of genetic similarity between populations. Between Fusarium spp. isolates, similarities ranged from 38 to 62% for interspecific and 62 to 94% for intraspecific comparisons. Two major groups were observed in the dendrogram, which was divided into three subgroups. One of them consisted the five F.oxysporum f. sp. vasinfectum isolates at the genetic similarity of 92%. Isolates Fov1, Fov3 and Fov5 showed high genetic relatedness (100%). With the second main cluster, at 62% similarity, one subcluster could be discerned; the subcluster contained F. oxysporum, F. solani, F. sambucinum, F. poae and Fusarium spp. isolates. These experiments reveal that microsatellite primers are reliable, sensitive and technically simple tools for assaying genetic variability in Fusaria. PRACTICAL APPLICATIONS The results presented herein indicate that a microsatellite technique provides an efficient tool for the identification of polymorphic loci that can be used to monitor the genetic differences between Fusarium species. Upcoming research is warranted to develop more microsatellite primers with a wider array of Fusaria.