Plant propagation through tissue culture may have been considered as early as 1902 when G. Haberlandt first attempted to regenerate plants from single cells. There are several potential practical applications of plant cell and tissue culture in agriculture. These include: induction of haploid plants from anther and pollen culture; protoplast culture; induction and selection of mutants; and clonal propagation or rapid multiplication of specific genotypes. The chapter also presents some of the key concepts discussed in this book. The book reviews the principles and practices for cloning various classes of agricultural crop plants via in vitro techniques in terms of currently available knowledge. It discusses the requirements for tissue culture propagation in both a general sense and in some cases for specific crops. The book provides an extensive list of references on plant cell and tissue culture for that particular class of agricultural plants.