Morphological and molecular differentiation between Quercus petraea (Matt.) Liebl. and Quercus pubescens Willd. (Fagaceae) in Northern and Central Italy

Quercus petraea (Matt.) Liebl. and Q. pubescens Willd. are two closely rela ted taxa. No specific single marker, either morphological or molecular, has been identified to distinguish the two species until now. In the present s tudy morphoanatomical and molecular traits (simple sequence repeats = SSR l oci) were investigated in an attempt to characterize and to discriminate be tween these two oak species. At the morphological level, the applied statis tics (nested ANOVA and discriminant analysis) suggest that the micromorphol ogical features are the most effective for this purpose. The wide range of macromorphological variation observed can confound the classification of ma ny individuals into either Q. petraea and Q. pubescens. Analysis of microsa tellite data indicates that most of the genetic variation is contained with in, rather than between, species. The lack of molecular divergence could be attributed to either relatively rapid and recent differentiation or to ext ensive hybridization following secondary contact of the taxa. (C) 2000 Anna ls of Botany Company.