The use of Simple Sequence Repeats (SSRs) to identify commercially important potato (Solanum tuberosum L.) cultivars in South Africa
The morphological traits that are traditionally used to identify potato cultivars are not always reliable, especially when dealing with in vitro plants. Various molecular marker techniques have been described for cultivar identification, but the Simple Sequence Repeat (SSR) technique has certain qualities that render it highly suitable for this application. In this study five SSR primer sets were used to characterize twenty-four commercially important potato cultivars. All profiles were found to be reliable and no variation was found between clones of the same cultivar. The number of polymorphisms detected with each of the markers varied, but none of the primers yielded only monomorphic fragments. The multilocus primer, STIIKA produced unique profiles for each of the 24 primer sets. However, the complicated nature of the profiles limits its use for routine diagnostic purposes. The use of the markers STS and STU 69633 in combination yields unique profiles for 20 cultivars and the fact that they can be analysed simultaneously on one gel, saves time and costs. The present study thus confirms that SSRs can be employed in a routine profiling system to provide highly discriminative and standardized profiles for South African potato cultivars.