Cybrids of Nicotiana tabacum and Petunia hybrida have an intergeneric mixture of chloroplasts from P. hybrida and mitochondria identical or similar to N. tabacum

Summary The mitochondrial genomes of cybrids of Nicotiana tabacum containing chloroplasts of Petunia hybrida were characterized by restriction endonuclease digestion and agarose gel electrophoresis. Cybrids that displayed normal growth and development contained mitochondrial DNA indistinguishable from N. tabacum mitochondrial DNA. Cybrids that displayed abnormal growth and development contained mitochondrial DNA that differed from N. tabacum either by possessing a few additional fragments, by lacking a few fragments, or both. In spite of these differences, the mitochondrial DNA of cybrids showing abnormal growth and development was much more similar to N. tabacum than to P. hybrida mitochondrial DNA. In those cybrids that contained P. hybrida chloroplasts and N. tabacum mitochondria, cotransfer of cytoplasmic organelles did not occur. Although P. hybrida chloroplasts can interact compatibly with the N. tabacum nucleus, no cybrids were found in which P. hybrida mitochondria coexisted with the N. tabacum nucleus.