EST-SSR marker-based assay for the genetic purity assessment of safflower hybrids

Full potential of any hybrid can be exploited by ensuring the supply of genetically pure seeds. Conventionally, hybrid seed purity assessment is done through grow out test (GOT) which is based on the morphological and floral characters of plants grown to maturity. Being land and labor intensive, time consuming and influenced by the environment, there is an immense need to replace GOT with a simple, rapid, unbiased and cost-effective DNA based assay for hybrid purity assessment. With this objective, the parental lines of three commercial safflower hybrids of India (NH-1, NH-15 and DSH-129) were screened using 74 safflower EST-SSR markers and five markers were found to be polymorphic. A PCR-based assay with these markers showed both alleles of the parental lines in pure hybrids proving the heterozygosity, while the off-types were identified by the presence of either of the parental alleles. This assay could accurately determine the genetic purity in a predetermined sample of hybrids constituted by deliberately mixing seeds of parental lines. This is the first report demonstrating the utility of EST-SSR markers for the assessment of genetic purity of hybrids in crop plants.