Genetic variability studies in early generation prebreeding restorer germplasm of the cross CBSN 25 x WRM 93-20.

The present investigation was carried out to understand the genetic variability, association, cause and effect relationships between yield and its attributing agronomic and physiological traits in 23 F₃ families of pre-breeding restorer germplasm in a hybrid rice program for six agronomic and three physiological characters. The variability and heritability parameters were grouped under the high category for the number of productive tillers per plant, leaf area per plant, dry matter production and single plant yield. The traits viz., the number of tillers per plant and panicle length, leaf area per plant and dry matter production showed a direct correlation with single plant yield and in cause and effect relationships. All traits had a direct influence on single plant yield except days to 50% flowering and chlorophyll index. At the intra-family level, six families namely 30, 35, 36, 46, 55 and 82 showed high variability and heritability values of all parameters for six traits. All nine traits exhibited normal distribution. [ABSTRACT FROM AUTHOR]