Application of ISSR Markers to Fingerprinting of Elite Cultivars (Varieties/Clones) From Different Sections of the Genus Populus L.

The Inter-Simple Sequence Repeat (ISSR) was used in this study for genetic fingerprinting and identification of 28 important Populus L. (poplar) cultivars (varieties/ clones), and determination of the genetic relationships among these cultivars. These 28 cultivars belonged to sections Aigeiros, Tacahamaca, Leuce, Turanga, and hybrids between sections Aigeiros and Tacahamaca. Out of 27 ISSR primers tested, eight primers generated clear multiplex profiles. The best three primers produced 154 easily detectable fragments, 129 (84%) of which were polymorphic among the cultivars. Each of these 3 primers produced fingerprint profiles unique to each of the accessions studied, and thus could be solely used for their identification. Twenty-five markers, unique to 10 of the cultivars studied, were detected. These markers may be converted into cultivar-specific probes for identification purposes. Genetic relationships among the cultivars were evaluated by generating a similarity matrix based on the simple matching coefficient and the unweighted pair group method with arithmetic average (UPGMA) dendrogram. The results showed a clear-cut separation of cultivars among different sections of poplar, and were in agreement with the genealogy of the sampled cultivars. The present study shows that ISSR markers could generate abundant polymorphism, are reproducible, and are quick for characterization of poplar cultivars. In the future, the markers used in this study, in combination with other molecular techniques, could provide a useful panel of ISSR markers for largescale DNA fingerprinting of poplar cultivars and determination of the genetic relationships among these cultivars.