Resistance assessment and biochemical responses of maize genotypes against Rhizoctonia solani f. sp. sasakii Exner causing Banded leaf and sheath blight disease

Maize (Zea mays L.) is a staple food in many parts of the world. In addition to being used as grain, animal feed, production of corn ethanol, starch, syrup etc., it has been widely consumed as a vegetable in the form of baby corn and sweet corn. Banded leaf and sheath blight (BLSB) is one of the major diseases affecting maize and is caused by Rhizoctonia solani f. sp. sasakii Exner. In the experiment forty six maize inbreds were screened for their reaction against the BLSB pathogen following artificial inoculation. Two inbred lines namely, EV1417 and CML-323 produced resistant and moderately resistant disease reaction respectively. Biochemical studies indicated the presence of a high level of pre-infectional barriers in the resistant line. Further, higher level of defense related enzymatic activities of peroxidase and poly phenol oxidase were detected in the resistant inbred line. After 48 h of inoculation, in comparison to highly susceptible EV1428, electrolyte leakage was found to be stabilized in EV1417 and CML-323. This study clearly establishes the presence of effective pre-infection barriers and induced biochemical defence mechanisms operating in the resistant inbred line. The identified resistant line EV1417 is further being used in BLSB disease resistance breeding programmes.