Electrophoretic evidence of relationships among Quercus (oaks) of eastern North America

Abstract

An evaluation of electrophoretic analysis as a potential tool for elucidating systematic relationships of Quercus utilized 478 trees representing 10 species from subgenus Erythrobalanus and 8 from subgenus Quercus. Leaf tissue was used to resolve 18 putative genetic loci representing 12 enzyme systems in each taxon. Subgeneric differentiation was apparent with intrasubgeneric genetic differentiation (mean modified Rogers' distance (D): Erythrobalanus 0.27; Quercus 0.44) being less than between subgenera (D = 0.68). Relationships among species within subgenera derived from electrophoretic data often compared well with published affinities. However, several discrepancies existed that might reflect disparities in rates of morphological, ecological, and allozymic divergence, or hybridization within subgenera, or both. Electrophoretic analysis of oak leaf tissue has the potential to yield valuable data for elucidating relationships among Quercus.