Gene cloning is the act of making copies, or clones, of a single gene. Once a gene is identified, clones can be used in many areas of biomedical and industrial research. Genetic engineering is the process of cloning genes into new organisms for altering the DNA sequence to change the protein product. Genetic engineering depends on our ability to perform the following essential procedures. Molecular cloning takes advantage of the fact that the chemical structure of DNA is fundamentally the same in all living organisms. The available information on gene cloning and transgenic development in horticulture crops has been compiled and it is hoped that this would be very useful to students and researchers in the field of biotechnology of horticulture crops. Therefore, if any segment of DNA from any organism is inserted into a DNA segment containing the molecular sequences required for DNA replication, and the resulting recombinant DNA is introduced into the organism from which the replication sequences were obtained, then the foreign DNA will be replicated along with the host cell’s DNA in the transgenic organism. The book has been designed for students, research scholars and teachers involved in the fields of microbiology, molecular biology, genetics, life sciences and biotechnology.