ABSTRACT
Several methods are available for transformation of plant cell through transfer of foreign DNA, chromosome fragments or chromosomes, involving cell cultures. The plant system, because of its flexibility and totipotency, has been subjected to different techniques of gene manipulation. These techniques, which are all aimed at horizontal transfer of genes directly from one organism to another, utilize in general naked protoplast system as the recipient. Microinjection is an effective method for injecting chromosome fragment or DNA in the recipient cell. This technique involves injection of a small amount of DNA solution into the recipient cell through pipette, capillary tube or injection under pressure. Genomic DNA is isolated from transgenic plants and digested with appropriate restriction enzymes. The fragments are separated by agarose gel electrophoresis followed by transfer to a nitrocellulose or a nylon membrane. Cold and salinity tolerance is introduced through genes coding for glycerol-3-phosphate and mannitol phosphate dehydrogenase respectively.
