INTERSPECIFIC TRANSFER OF ISOLATED PLANT-MITOCHONDRIA BY MICROINJECTION

Data on isolation, purification and transfer of mitochondria from a cy toplasmic male sterile line of the ''Ogura'' type of Raphanus sativus to a male fertile line of Brassica napus are reported. Microinjection has been used for the transfer of the donor mitochondria to the recipi ent protoplasts. The injected protoplasts were identified and followed individually throughout their development using a computerized micros cope stage which greatly enhanced the number of injections (five-fold) . The transferred donor mitochondria were stably maintained during sev eral successive cell divisions, revealing that they were viable and fu nctional. Several calluses were obtained from injected protoplasts wit hout using any selection pressure. Restriction fragment length analysi s of seventeen calluses, using mitochondrial DNA probes, indicated tha t three contained the donor ''Ogura'' type mitochondria. No recombinan t types of mitochondria have been observed. Flow cytometric and karyot ype analyses of the calluses revealed the presence of similar amount o f DNA and chromosome number as those of the recipient plants of B.napu s. The application of microinjection for the manipulation of cytoplasm ic composition is discussed.