Factors influencing the utility of gametic microprotoplasts for partial genome transfer in potato

The potential of gametic microprotoplasts as a tool for partial genome transfer in potato (Solanum tube-rosum L.) was investigated and a number of technical findings are reported. The phosphoric amide herbicide amiprophos-methyl was effective for microcell induction when applied at a concentration of 25 mu M to excised anther material: however, neither whole buds nor isolated microspores responded to treatment. One selected clone responded well to spindle toxin treatment, and microcells were observed in 9% of tetrads, for which 4% (wt/vol) cellulase Onozuka R10 and 0.25% (wt/vol) driselase was found to be optimal for the release of protoplasts from the tetrads with conversion rates exceeding 40%. Technical problems identified at a number of crucial stages that may preclude the more widespread application of this technology are discussed.