AMRUTA S. BHAT, T.B. AN ILKUMAR AND V.B. SANATH KUMAR
Abstract
To assess the potential role of 13-1, 3-glucanase enzyme in defense response of finger millet, time course of its induction was studied at both leaf and neck blast stages after artificial inoculation of susceptible (K-7), moderately resistant (GPU-26), resistant (GPU-28) and highly resistant (I8IE) genotypes with P. grisea. The results obtained revealed that the enzyme was induced upon inoculation in all the four genotypes. However, there was no definite correlation between percentage of induction and degree of resistance of different genotypes. Total activity in the inoculated leaf samples reached its peak at 5 DAI and then it declined in all the genotypes except in K-7, where there was a continuous increase in activity during the course of study. In neck samples, enzyme activity reached its peak at 14 DAI and then it declined. Both during leaf blast and neck blast stages constitutive levels of the enzyme as well as its levels upon inoculation were higher in the resistant (GPU-28) and highly resistant (I8IE) genotypes except at later stages of leaf blast where it was higher in susceptible (K-7) genotype. Higher levels of enzyme activity present in the resistant genotypes might contribute for the resistance by restricting the pathogen at early stages itself.