Population Genetic Structure of Fusarium oxysporum f. sp. ciceris, the Causal Agent of Chickpea Wilt, Using SSR Markers in West and Northwest of Iran

Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris is one of the major yield-limiting factors in chickpea, particularly in west and northwest of Iran. Simple Sequence Repeats (SSR) were used to determine genetic structure of Fusarium oxysporum f. sp. ciceris populations from three infected areas located in west and northwest provinces of Iran during 2016-2017. A set of six microsatellite primer pairs revealed 35 alleles in each locus with an average of 5.83 per locus. The PIC value varied from 0.20 (FOAG11) to 0.39 (FODF7) with an average of 0.27 per locus. The average number of effective alleles (Ne), Number of private alleles (Na), allelic variability per locus (H), Shannon's Information Index (I) and percentage of Polymorphic Loci (%PL) in three populations were 1.33, 1.97, 0.2208, 0.357, and 74.29, respectively. The average genetic distance was calculated among the three populations. Nei’s pair-wise genetic distances between the populations varied from 0.0202 to 0.98. The total gene diversity (Ht) and gene diversities between subpopulations (Hs) were estimated to be 0.2208 and 0.2079, respectively. Gene diversity attributable to differentiation among populations (Gst) was 0.0585, while gene flow (Nm) was 8.0412. The AMOVA of genetic variation in Fusarium oxysporum f. sp. ciceris populations revealed that 5% of the variance occurred among populations and 95% within populations. PhiPT value was 0.054. The lowest genetic distance was found between Kurdistan and West Azerbaijan with Lorestan populations, while the highest genetic distance was observed between Lorestan and Kermanshah populations.