Mitochondrial genome structure of a cytoplasmic hybrid between tomato and wild potato.

A physical map of the mitochondrial genome was constructed for a male-sterile tomato, MSA1, which had been generated by an asymmetric cell fusion between tomato (Lycopersicon esculentum) and wild potato (Solanum acaule). The entire genomic sequence of the MSA1 mitochondria (450 kb) was represented by five maps. Even if sequence duplications were taken into consideration, at least two linkage groups (maps 1-4 and map 5) were necessary to show the overall genome. The mitochondrial genome structure of MSA1 was also analyzed by comparing the Southern hybridization patterns of MSA1 and its parents (tomato and wild potato). The mitochondrial genome of MSA1 consists of a complex mixture of the parental genomes with at least 11 molecular recombination events.