The genetic similarities of 19 hybrid rice parental lines were estimated using
morphological traits and RAPD markers. Mahalanobis distance and standard
taxonomic distance were computed from ten quantitative morphological traits.
Molecular genetic distances derived from Dice’s similarity coefficients were based on
133 RAPD markers. Cluster dendrograms were generated for both the standard
taxonomic distances and molecular genetic distances. Genetic variability existing
among thermo-sensitive genic male sterile (TGMS) lines was much lower than that
among cytoplasmic genic male sterile (CMS) lines. Standard taxonomic distance
method was found to be a more accurate method in clustering genotypes as compared
to Mahalanobis distance method. PCR analysis based on 10 RAPD primers could
detect sufficient polymorphisms for the germplasm characterization and genetic
distance study. The cluster analysis based on RAPD markers was able to reveal close
genetic relationships between different rice genotypes used in the hybrid rice breeding
program.