Morphological and Molecular Analysis of Putative Hybrid Speciation in Ceanothus (Rhamnaceae)

摘要: Abstract Several species in the North American shrub genus Ceanothus L. are purported to be diploid hybrid-derived species, isolated and stabilized from congeners by geographic barriers. masonii C. sonomensis putatively of hybrid origin each derived independently cuneatus var. gloriosus exaltatus. We tested this hypothesis using allozyme, morphometric data, sequences internal transcribed spacers (ITS) 5.8S coding region nuclear ribosomal DNA (nrDNA) chloroplast-encoded matK gene. found all four entities closely related genetically. Lack genetic differentiation made it difficult evaluate hypothesis. The alternative primary allopatric divergence is just as reasonable an explanation for our data. Communicating Editor: Paul Wilson