The Journal of Heredity 2002:93(3)
© 2002 The American Genetic Association 93:174-178
Inheritance of Organelle DNA Sequences in a Citrus–Poncirus Intergeneric Cross
From the University of Florida, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, Gainesville, FL 32611-0690 (Moreira, Ortega, and Chase), and CREC, P.O. Box 1088, Lake Alfred, FL 33850 (Gmitter, Grosser, and Huang).
Address correspondence to C. D. Chase at the address above or e-mail: ctdc{at}mail.ifas.ufl.edu.
Many land plants deviate from the maternal pattern of organelle inheritance. In this study, heterologous mitochondrial and chloroplast probes were used to investigate the inheritance of organelle genomes in the progeny of an intergeneric cross. The seed parent was LB 1–18 (a hybrid of Citrus reticulata Blanco cv. Clementine x C. paradisi Macf. cv. Duncan) and the pollen parent was the cross-compatible species Poncirus trifoliata (L.) Raf. All 26 progeny examined exhibited maternal inheritance of plastid petA and petD loci. However, 17 of the 26 progeny exhibited an apparent biparental inheritance of mitochondrial atpA, cob, coxII, and coxIII restriction fragment length polymorphisms (RFLPs) and maternal inheritance of mitochondrial rrn26 and coxI RFLPs. The remaining nine progeny inherited only maternal mitochondrial DNA (mtDNA) configurations. Investigations of plant mitochondrial genome inheritance are complicated by the multipartite structure of this genome, nuclear gene control over mitochondrial genome organization, and transfer of mitochondrial sequences to the nucleus. In this study, paternal mtDNA configurations were not detected in purified mtDNA of progeny plants, but were present in progeny DNA preparations enriched for nuclear genome sequences. MtDNA sequences in the nuclear genome therefore produced an inheritance pattern that mimics biparental inheritance of mtDNA.