Abstract
The mitochondrial genome of Petunia hybrida contains two transcribed cytochrome oxidase subunit II(coxII) genes. The coding region of both genes is split by a 1.3 kb group II intron. Unlike coxII-1, which is similar to other sequenced plant coxII genes, the coxII-2 coding region is extended by 48 codons. The cytoplasmic male sterile (CMS) Petunia contains one coxII gene similar in structure and transcript pattern to the coxII-1 gene found in the fertile genome. Comparison of the sequenced coxII genes from the fertile mitochondrial genome with the coxII sequences present in the CMS-associated pcf gene from the CMS genome (Young and Hanson 1987) suggests that pcf is a processed pseudogene. A model for the generation of pcf is presented.