CREMART - A NEW CHEMICAL FOR EFFICIENT INDUCTION OF MICRONUCLEI IN CELLS AND PROTOPLASTS FOR PARTIAL GENOME TRANSFER

Results on efficient induction of micronuclei by Cremart in suspension cells and protoplasts of potato are reported. Cremart is a highly eff ective phosphoric amide herbicide, which acts on the mitotic spindle, and induces micronuclei through modification of mitosis. After treatme nt with Cremart, metaphase chromosomes changed directly into micronucl ei without centromere division and chromatid separation. When suspensi on cells were treated with Cremart (3.7 - 15.0 mu M) for 48h, and subs equently incubated in a mixture of cell wall-digesting enzymes in the presence of cytochalasin-B and Cremart for 18h, the frequency of micro nucleation in the cell/protoplast mixture increased significantly, as compared to that obtained after treatment of suspension cells with Cre mart (3.7 15.0 mu M) for 48 h. Sieving after enzyme incubation resulte d in the recovery of protoplasts, showing mass induction of micronucle i. Also synchronized suspension cells of Nicotiana plumbaginifolia res ponded with high frequency of micronucleation after Cremart (3.7 mu M) treatment. The application of this procedure for partial genome trans fer is discussed.