Citrus transformation using mature tissue explants.

Mature tissue protocol for production of transgenic Citrus plants via Agrobacterium-mediated transformation uses explants derived from branches of mature, fruit-bearing trees. Through the multiple cleaning steps consisting of grafting of apical tip meristems on rootstock plants grown under sanitary conditions, "mother" plants are produced that will serve as a source of budding material. These buds are grafted onto rootstock plants grown under the same, highly sanitary conditions.