Analysis of population genetic structure of Iranian Fusarium oxysporum f. sp. lentis isolates using microsatellite markers

Abstract

Lentil (Lens culinaris Medik.) is an important widely cultivated food legume crop in Iran. Wilt disease caused by Fusarium oxysporum f.sp. lentis has been observed with high losses in some of cultivated areas during recent years. Simple sequence repeat (SSR) were used to determine the genetic structure, and estimate genetic diversity in 101 of Fusarium oxysporum f. sp. lentis (FOL) isolates from five counties in Ilam provinces of western Iran (Sarableh, Sirvan, Ivan, Badreh, Darehshahr). A set of five microsatellite primer pairs revealed a total of 10 alleles each locus across the five populations; the number of alleles varied from 6 to 9 for each population. A low level of genetic variability was observed among FOL isolates in the region. Genetic diversity was low (H = 0.234) within populations with corresponding high average gene flow and low genetic distances between populations. The smallest genetic distance was observed between isolates from Sirvan and Badreh. Observed allele number (Na) and effective numbers (Ne) of alleles were higher in Ivan in comparison to other populations. The number of (H) and (I) were also higher in Ivan (H = 0.301; I = 0.442). The total gene diversity (Ht) and gene diversities between subpopulation (Hs) were estimated 0.267 and 0.233, respectively. Gene diversity attributable to differentiation among populations (Gst) was 0.126, while gene flow (Nm) was 3.439. Cluster analysis based on UPGMA showed the lowest genetic distance between Sirvan and Badrah, than between Sarableh and Sirvan. The dendrogram indicated a clear break between the population from Darehshahr and the four remaining populations. Results from this study will be useful in breeding for Crown and root rot resistant cultivars and developing necessary control measures.