Genetic engineering has begun about 160 years ago with discover inheritance laws of biological traits, isolation and purification of DNA from inner cell, replication and propagation of its pieces with polymerase chain reaction in vitro, identification and purification favorable genes and transfer them with Agrobacterium  tumefaciens bacterium, or directly to plants cell, by gene gun, and produce whole transgenic  plant, from gene modified cell with tissue culture methods innovation and fully developed in recent 4 decades. With this technology transfering  favorable genes, without accompaniment with  unwanted genes, into plants is possible, and resistance transgenic plants to fungal, bacterial, viral and nematodes, and tolerant to environmental stress produced. Genetic engineering has created hope for better plants diseases management and increase agricultural production to meet food needs of a growing human population.