Hybridization is a process of great importance in the ecology and evolution of plants. However, identifying hybrids is not an easy task, especially in cases of sympatry. Such cases are the Abies taxa in Greece; Silver fir (A. alba), Greek fir (A. cephalonica) and King Boris fir (A. × borisii-regis). The latter has been characterized as a hybrid between the first two species as its morphological traits are either a combination of the parental ones or intermediate. Besides the morphological traits, A. × borisii-regis has so far been identified only at the population level, with biochemical and DNA markers. Here, we describe the identification of A. × borisii-regis at the individual level by employing a species-specific marker in the cpDNA and another in mtDNA, taking advantage of their uniparental inheritance mode from the paternal and the maternal parent, respectively. In addition, based on these markers, essential information emerges on the distribution and the mtDNA diversity of the Abies taxa in Greece. Keywords: Abies; Abies × borisii-regis; species-specific markers; mtDNA; cpDNA; hybrid
