Identification of Blast Resistant Breeding Lines through Uniform Blast Nursery in Rice (Oryza sativa L.)

Rice blast disease caused by the fungus Magnaporthe oryzae is the most devastating disease of rice causing considerable yield losses. Development of resistant varieties is the most effective and environment friendly strategy to combat losses. RNR 15048 (Telangana sona) (IET23746) is a popular local variety possessing a desirable, short-slender grain type with low glycemic index, good cooking quality and having Pi2 gene for blast. However, it is moderately susceptible to bacterial blight disease and having no durable resistance to blast disease with weak culm. In this context, improvement of RNR 15048 for blast, bacterial leaf blight is important to reduce yield losses. Present study was carried out to screen and identify blast resistant breeding lines in Rice at Regional Agricultural Research station, Polasa, Jagtial, PJTSAU during Rabi, 2022-2023. 18 F3 breeding lines were screened in uniform blast nursery along with parents RNR 15048, MTU 1010 NILs, ISM NILs. TN1 and NLR 34449 were used as the susceptible and resistant checks, respectively for screening blast resistance. Screening was done by following 0-9 Standard Evaluation Scale (SES) for leaf blast. Among the studied 18 F3 breeding lines 12 lines were found resistant with score of 3 and 6 lines were found moderately resistant to screening reaction with score of 5. TN1 showed highly susceptible reaction with score of 9 and NLR 34449 showed highly resistant reaction with score of 1.