Nuclear ribosomal DNA (nrDNA) concerted evolution in natural and artificial hybrids of Armeria (Plumbaginaceae)

Nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) sequences from artificial hybrids and backcrosses between Armeria villosa ssp. longiaristata and A. colorata were studied to assess the possible effects of concerted evolution in natural hybrids. F1 artificial hybrids show the expected pattern of additive polymorphisms for five of the six variable sites as estimated from direct sequences. However, homogenization of polymorphism is already observed in the F2, and is biased towards A. colorata except for one site. In backcrosses, an expected tendency towards homogenization of polymorphic sites in the direction of the recurrent parent is observed for five sites, although this does…