The CO2 compensation point and its relation to the chloroplast DNA (cpDNA) type were investigated on the somatic hybrids between Brassica oleracea , a C3 plant and Moricandia arvensis, a C3-C4 intermediate plant. The fragment patterns of cpDNA digested with restriction endonuclease (XhoI) showed that the somatic hybrid plants had the cpDNA of either B. oleracea or M , arvensis. Out of 11 plants investigated, 5 plants had the cpDNA of B. oleracea, while 6 had that of M. arvensis. However, both

more »

... pes of the hybrids showed as high a CO2 compensation point as B. oleracea irrespective of their cpDNA . In this respect, the C3-C4 intermediate character of M. arvensis was not expressed in the hybrids. Abbreviations: cpDNA, chloroplast DNA; T, CO2 compensation point .