Frankel, R., Division of Plant Industry, CSIRO, P.O. Box 1600, Canberra City, 2601, A.C.T., Australia
Scowcroft, W.R., Division of Plant Industry, CSIRO, P.O. Box 1600, Canberra City, 2601, A.C.T., Australia
Whitfeld, P.R., Division of Plant Industry, CSIRO, P.O. Box 1600, Canberra City, 2601, A.C.T., Australia

Chloroplast DNAs of six isonuclear malesterile tobacco lines and their respective parental species were analysed with the restriction endonuclease, EcoR1. Four of the lines had the same fragmentation pattern as their respective maternal species. Two lines had a pattern which was different to either parental species. The results show that nucleotide changes can occur in chloroplast DNA of isonuclear male-sterile lines, and are discussed in relation to the possible involvement of chloroplast DNA in cytoplasmic male-sterility in tobacco. © 1979 Springer-Verlag.