editorial

Regarding C. maxima and C. aveallana: C. avellana and C. maxima genotypes were distinctly separated from other species based on analysis of ITS sequences. Corylus avellana has been divided into subgroups that some authorities accept as distinct species (C. maxima Mill., C. pontica Koch., and C. colchica Alb.) closely related to C. avellana (Kasapligil 1972). Others would consider these three "species" to belong to one polymorphic species, C. avellana, as they show continuous variation in morphology, easily hybridize with each other, and overlap in geo graphic distribution (Mehlenbacher 1991; Rovira 1997; Thompson et al. 1996). In this study, 'Tombul Ghiaghli' (avellana-3) could be considered a rep resentative of C. pontica, and 'San Benedetto' and 'Pellicle Rouge' could be considered representatives of C. maxima. Phylogenetic analysis of both nuclear ribosomal ITS region and matK sequences showed that genotypes of C. axima and C. pontica always clustered with those of C. avellana.

Erdogan, V.; Mehlenbacher, S.A. 2000: Phylogenetic relationships of Corylus species (Betulaceae) based on nuclear ribosomal DNA ITS region and chloroplast matK gene sequences. Systematic Botany 25: 727–737.