Development of genomic SSR markers and genetic diversity of Sphaerulina musiva in China

Abstract

AbstractSphaerulina musiva is an important poplar pathogenic fungus that causes leaf spot and stem canker. SSR markers serve as excellent molecular markers for assessing genetic diversity in fungi. To date, few SSR markers have been developed and applied in S. musiva. In this study, genomic‐SSR markers were developed from the S. musiva genome, and applied to analyse the genetic diversity of S. musiva isolates from Henan province in China. A total of 9923 SSR loci were identified with a relative abundance of 343.15 SSR loci per Mb. Tri‐nucleotide repeats were the most abundant in five types of SSRs, and accounted for 56.82% of the total SSR loci. Twelve genomic‐SSR markers were successfully developed from tri‐nucleotide SSR loci. The number of alleles per locus ranged from 3 to 8 with an average of 4.08 alleles. The polymorphism information content of these loci ranged from 0.428 to 0.770, with an average of 0.553. Based on the SSR markers, a total of 48 haplotypes were identified from 48 S. musiva isolates. Forty‐eight isolates were divided into four main genetic groups at a genetic distance of 0.21. Genetic relationships of the isolates had no obvious correlation with geographic origin. It is the first time to develop genomic SSR markers in S. musiva. The developed SSR markers will be a useful tool to evaluate genetic diversity and population structure of S. musiva.