Population genetic structure of Fusarium verticillioides the causal agent of corn crown and root rot in Ilam province using Microsatellite markers

Analysis of genetic diversity of Fusarium verticillioides populations concludes different levels of information in management of crown and root rot disease in corn farms. Simple sequence repeat (SSR) markers were used to determine genetic structure and estimate genetic diversity in 77 F. verticillioides isolates from major producing areas in Ilam province, Iran such as: Dehloran, Mosiyan, Dasht Abas, Mehran, Eivan, Holeylan and Darreh Shahr during 2016 - 2017. Nine microsatellite (SSR) primer pairs revealed that the average number of alleles in populations were 34, the number of alleles in populations varied from 27 alleles in Dehloran and Mosiyan as the lowest to 40 alleles in Darreh shahr as the highest. Observed alleles (Na) number and effective number of alleles (Ne) were higher in Mehran (Na = 1.860; Ne = 1.463) compared to other populations. The genetic diversity (He) was higher in Holeylan (He = 0.284) and Shannon's information index (I) was also higher in Mehran (I = 0.436) but lower values were estimated for Mosiyan (He = 0.195; I = 0.303). The lowest genetic distance was found between Dehloran and Mosiyan (0.013) while the highest genetic distance was revealed between Dehloran and Darehshahr (0.139). Total gene diversity (Ht) and gene diversities between subpopulations (Hs) were estimated at 0.292 and 0.249 respectively. Gene diversity attributable to differentiation among populations (Gst) was 0.147, while gene flow (Nm) was 2.890. Cluster analysis based on UPGMA showed the lowest genetic distance between Dehloran and Mosiyan and then Dasht abas. The dendrogram indicated a high genetic distance between Darehshahr and the six remaining populations. Results from this study will be useful in breeding program of crown and root rot resistant cultivars and developing control methods for this disease.