Genetic Diversity and Mating-Type Frequency of Exserohilum turcicum in Turkey

Abstract

Northern corn leaf blight caused by Exserohilum turcicum is one of the most significant diseases in maize-growing fields, resulting in yield reduction worldwide. Genetic diversity and mating-type of E. turcicum were determined using isolates collected from 7 important maize cultivation provinces in 4 different geographic regions of Turkey during 2014-2015. Multilocus haplotypes of E. turcicum isolates were characterized using 13 simple sequence repeats (SSR) primer pairs, which were amplified in PCR multiplex reactions. The evaluation of mating-type ratio generated from the E. turcicum population was by chi(2) significance test. MAT-1 and MAT-2 mating-type were shown in the population; however, the chi(2) significance test did not support the sexual reproduction hypothesis in any region. The E. turcicum population was found to produce predominantly asexual reproduction in Turkey. Numerous E. turcicum isolates showed very high genetic similarity and did not show a distinct cluster dependent on region or mating-type on a dendrogram of genetic diversity. This result showed that one-hundred per cent similarity in most of the collected isolates from different regions might also support long-distance migration.