Genetic Diversity among US Sunflower Inbreds and Hybrids: Assessing Probability of Ancestry and Potential for Use in Plant Variety Protection

We report on the ability of microsatellites or simple sequence repeats (SSRs) to discriminate sunflower (Helianthus spp.) inbred lines and hybrids that are well adapted and widely used in the United States. Associations of inbreds were consistent with known pedigrees; groupings were often consistent with designations as either female or male parents. All of the hybrids were uniquely identified; most grouped according to source company. Pedigree analysis of 15 hybrids of known parentage correctly identified the two parental inbreds for each hybrid. The pedigree algorithm was robust in the face of missing and misscored data, especially when data from at least 75 SSRs were used. The SSR profiles could be used to facilitate evaluations of distinctness that are required to obtain plant variety protection through the improved management of reference collections, and they could also be used to help determine essentially derived variety status in plant variety protection in sunflower.