Evaluation of several important defense enzyme activities in mutant rice resistant to blast disease

Blast disease, caused by fungus Magnaporthe grisea (Hebert) Barr, with asexual form Pyricularia grisea (Cooke) Sacc, is the main fungal disease of rice in the tropical and temperate regions of the world and Iran. Mutant plants derived from mutation breeding due to having the same genetic background with their wild-type are useful experimental material for comparative analysis and dissecting molecular mechanisms. For this purpose, seeds of two rice genotypes including mutant variety (Pooya) and its wild-type parent cultivar (Mosatarom) were prepared from Rice Research Institute of Iran and used in greenhouse tests. Evaluation of resistance components showed that Pooya mutant variety was resistant and Mosatarom cultivar was susceptible. Biochemical analysis under control and inoculated conditions revealed that enzyme activities of catalase, peroxidase, polyphenol oxidase in the Pooya mutant variety was more than, while TBARM index was lower than Mosatarom cultivar. According to the positive role of defense enzymes in controlling disease progression, Pooya mutant variety had better than its wild-type parent cultivar against blast disease due to the maximum defense enzyme activity.