Disease reaction studies of maize (Zea mays L.) against turcicum leaf blight involving indigenously identified cytosterile source

Among biotic stresses affecting maize, the turcicum leaf blight caused by Exserohilum turcicum is one of the most important diseases in India. Disease reaction studies against turcicum leaf blight were done with two crosses viz., 15C (A) x I-318 (R) and I-401(A) x I-318(R) for all six generations with P1, P2 and F1 having 30 plants each and F2 (300 plants), BC1 (180 plants) and BC2 (180 plants). Analysis of variance of arc sin transformed data for leaf blight in the present study revealed significant variability has been exhibited by fungus to infect different generations of a particular cross. In I-15C(A) x I-318(R) cross, F1 was moderately resistant to turcicum leaf blight but F1 of I-401(A) x I-318(R) cross was moderately susceptible to the disease. Disease screening of both crosses indicated that the latent period was longer, suggesting presence of resistant genes in both the crosses which further can be exploited in the production of successful commercial hybridsby using these CMS sources as parents to develop turcicum leaf blight (TLB) resistant, cost effective and stable hybrids. Key words: Maize, Zea mays L., turcicum leaf blight, cytosterile source.