Biochemistry Laboratory, Dept. of Soil Science and Agricultural Chemistry College of Agriculture, Central Agricultural University, Imphal - 795004, India.
*Corresponding author;
**Part of thesis submitted by the co-author for award of M. Sc. Degree of the Central Agricultural University, Imphal.
Rice plants with sheath blight infection were collected from 3 rice growing districts of the Imphal valley. They were brought and purified in the laboratory as Isolate- 1, Isolate- 2 and isolate- 3, respectively. All the pathogens reacted differently to different rice varieties. The isolate- 1 and isolate- 3 were found to be more virulent than isolate- 2 which was also supported by extracellular production of cellulase, pectolytic and protease enzyme activities. Isolate- 1 was found to be superior in protease, PME and PMG enzyme production whereas isolate- 3 was superior in cellulolytic enzyme production. Isolate- 2, on the other hand could not appreciably use cellulose and pectic substances due to limitations from low production of exo-glucanase, PME and PMG enzymes. The districts from where isolates 1 and 3 were collected happen to be agriculturally advanced districts with full introduction of high yielding and hybrid varieties. The present experiments suggest the possibility of existing at least 3 physiological races of Rhizoctonia solani causing sheath blight of rice in Imphal valley.
Rhizoctonia solani, virulence, resistance, susceptibility, protease, endoglucanase, exoglucanase, β-glucosidase, Pectinmethylesterase (PME) and polymethylgalacturonase (PMG)
