Leaf rust, caused by Puccinia triticina Erikss. (Pt), is the most widespread wheat rust disease. Information on the virulence and genetic diversity of Pt is important for understanding the pathogen evolution, and thus effective management of wheat leaf rust. We used 20 Thatcher wheat near isogenic lines to study virulence diversity of 102 Pt isolates collected from tetraploid wheat, common wheat, and Triticale worldwide. Seven races were found among 57 isolates collected from tetraploid wheat while 21 races were observed among 40 common wheat type isolates. Four races were identified among the five isolates collected from Triticale. A subset of 30 Pt were genotyped using the Restriction-Associated DNA (RAD)-Genotype By Sequencing (GBS) adapted for the Ion Torrent sequencing platform. Phylogenetic analysis on 30 isolates using 2,125 SNP markers showed eight clusters supported by high bootstrap values. We observed higher genotypic diversity in common wheat type isolates compared to that in tetraploid wheat type isolates. Generally, there was a correlation between virulence phenotypes and SNP genotypes. Phylogeny results suggest that RAD-GBS is promising as a new technique for the study of population genetics in P. triticina.
Genotype by sequencing for the study of population genetics in Puccinia triticina
Poster or Plenary?: