(i) Recombinant DNA is introduced into host Agrobacterium tumefaciens cells. The genes are then inserted into plant cells.
(ii) RNA of TMV with desired genes is introduced into tobacco plants.
Role of recombinant DNA in development of high yielding varieties
High yielding varieties have been created by introducing desired genes from wild species into crop plants. Genes producing beta carotene and iron from daffodil plant have been introduced into rice, wheat, bhutra, soybean, potato, tomato, papaya, rye, sunflower, pear, grape etc. to create high yielding varieties.