Virulence Pattern of Pathotypes Towards Blast Monogenic Lines.

Rice blast caused by () is one of the most serious diseases infecting rice worldwide. In the present study, virulence pattern of six pathotypes (P0.0, P0.2, P1.0, P3.0, P7.0 and P9.0) identified from the blast pathogen collected in Peninsular Malaysia, were evaluated using a set of 22 IRRI-bred blast resistance lines (IRBL) as well as to determine the resistance genes involved. The information on the virulence of the blast pathotypes and the resistance genes involved is important for breeding of new rice variety for durable resistance against blast disease. The IRBL was established from 22 monogenic lines, harbouring 22 resistance genes [, and ]. Based on the disease severity patterns, the tested pathotypes were avirulence towards seven IRBLs [IRBLi-F5, IRBLk-Ka, IRBLkh-K3, IRBLz-Fu, IRBLsh-S, IRBLPi7 (t) and IRBL9-W] of which these IRBLs harbouring , and resistance genes, respectively. Therefore, the results suggested that the seven IRBLs carrying seven resistance genes [, and ] would be suitable candidates of resistance genes to be incorporated in new breeding lines to combat the current blast pathotypes in the field.