Genetic engineering through DNA recombinants and the in vitro manipulation of isolated protoplasts has recently attracted much atten- tion in agricultural biotechnology, and has greatly advanced during the last 5 years. In an earlier book, Plant Protoplasts and Genetic Engineer- ing I, methods for the isolation, fusion and culture of protoplasts were reviewed and the regeneration of complete plants from isolated pro- toplasts of rice, potato, soybean, linseed, cabbage, chicory, lettuce, but- terbur, orchids, citrus and some other tree species, and interspecific and intergeneric somatic hybrids in Lycopersicon, Petunia, Nicotiana, Solanum, Glycine, Citrus, Brassica, Medicago and Trifolium spp. were discussed. The present volume, Plant Protoplasts and Genetic Engineering II, deals with some of the newer techniques such as microinjections, elec- trofusion, flow cytometry, uptake and integration of DNA, nuclei, iso- lated chromosomes by plant protoplasts and the subsequent regeneration of transgenic plants. The literature on the DNA recombinants and genetic transformation, both Agrobacterium-mediated and direct gene transfer in agricultural crops and trees, such as poplars, is reviewed, and the uses of cytoplasts and miniprotoplasts in genetic manipulation are highlighted.