Loss of CMS-specific mitochondrial DNA arrangement in fertile segregants of Petunia hybrids.

The progeny of somatic hybrid Petunia plants derived from the fusion of a male-fertile line and a cytoplasmic male-sterile (cms) line were examined. Male-fertile progeny derived from three different male-sterile somatic hybrid plants did not exhibit the mitochondrial DNA (mtDNA) arrangement which has previously been correlated with cms in Petunia. The cms-associated mtDNA arrangement was present in the male-sterile predecessors of these fertile revertants. Thus, it is concluded that the loss of this mtDNA arrangement is associated with reversion to fertility in the progeny of the unstable somatic hybrid petunia plants.