Phenotypic and molecular characterization of diversified cytoplasmic male sterile lines of rice (Oryza sativa L.)

Genetic diversity in cytoplasmic male sterile (CMS) lines of rice incorporating attributes of locally preferred varieties is essential to help reduce genetic vulnerability and produce desirable heterotic combinations. Seventeen diverse CMS lines were developed by backcrossing five CMS sources with six Indian rice varieties. Phenotypic evaluation of the CMS lines at seven locations exhibited superior agronomic and floral attributes. Genetic diversity study based on 45 polymorphic microsatellite markers exhibited high genetic dissimilarity (0.65) indicating diversification of CMS genotypes. The UPGMA based dendrogram showed distinct clusters indicating wide genetic diversity. Principle component analysis supported distinct clustering. CMS line specific SSR markers were detected which can help to monitor genetic purity. New CMS lines will enrich the genetic resource and allow selection of appropriate CMS lines for developing high yielding hybrids with desirable traits and reduce the risk associated with genetic uniformity