Analysis of Pyricularia oryzae isolates from rice and weeds with rep-PCR marker and pathogenicity

Pyricularia oryzae is the cause of blast leaf spot disease on rice and more than 50 plant species of crops and weeds in Poaceae family. Sampling was performed in 2017 in rice fields of Guilan and Mazandaran provinces. Morphological studies showed that the isolates obtained from Oryza sativa, Setaria viridis, Echinochloa crus-galli, Sorghum halepense, and Paspalum dilatatum were belonged to P. oryzae. The pathogenicity test revealed that isolates obtained from each host had higher pathogenicity on the same host and were either not pathogenic or less pathogenic on other hosts. Cluster analysis of DNA fingerprinting data using rep-PCR showed that isolates obtained from different hosts were located in three clonal lineages. In general, there were isolates from different hosts in all three identified clonal lineages, and no correlation was found between the similarities of the band pattern with their collection areas.