Pattern of genetic variation in rice (Oryza sativa L.) population for sheath blight resistance over the seasons

A set of 192 indica rice accessions were evaluated in two seasons to generate information on the extent of genetic variability, broad-sense heritability and genetic advance for yield and sheath blight related traits. The estimated genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) varied over the season. Largely, PCV values were relatively higher than GCV with reference to the studied parameters. However, GCV was found to be medium for per cent disease index (PDI) of 14th day, 28th day, area under the disease progress curve (AUDPC), and tiller number over the seasons. Interestingly, grain yield was found to be high. The trait plant height and panicle length had moderate heritability coupled with moderate genetic advance, whereas AUDPC was moderately heritable coupled with high genetic advance. The findings may be useful in breeding improved rice genotypes.