MOLECULAR AND PATHOGENIC VARIATION IDENTIFIED AMONG ISOLATES OF RHYNCHOSPORIUM SECALIS FROM SYRIA
M.I.E. Arabi, M. Jawhar, E. Al-Shehadah
The fungus Rhynchosporium secalis is the causal agent of barley scald disease. Sixty-three isolates of diverse geographical origin within Syria were analyzed for pathogenicity and variability of genomic DNA through random amplified polymorphic DNA (RAPD) markers. The isolates were highly variable and 18 unique haplotypes were identified. A neighbour-joining diagram, based on Nei’s genetic distances, showed that isolates formed three phylogenetic groups, and did not fall into clusters linked with geographical origin or pathogenicity, which suggests a regional dispersal of the fungus. However, most isolates with different pathogenicity levels were in the same clusters. The information obtained from this study is crucial for studying genetic variation in R. secalis and is important for future selection of isolates to develop durable barley scald resistance.