Plastid Inheritance and Plastome-genome Incompatibility of Intergeneric Hybrids between Menziesia and Rhododendron

Abstract

Intergeneric hybridization between Menziesia and Rhododendron generates many albino or pale-green seedlings. To clarify the factors that cause albino phenotype, we analyzed the inheritance of plastid (pt) DNA by PCR-RFLP analysis on the intergeneric hybrids between two genera and an intraspecific hybrid within Menziesia by reciprocal cross-pollination, respectively. All albino and pale-green intergeneric progenies contained the ptDNA of Rhododendron, whereas green progenies contained that of Menziesia, indicating that Rhododendron plastome is incompatible with Menziesia nuclear genome. Moreover, when M. multiflora was used as a female parent, most progenies transmitted their plastids paternally. Plastome-genome incompatibility seems to be independent from ptDNA inheritance in Menziesia-Rhododendron hybrids.