Urbanization and industrialization pose a great threat to biodiversity due to destruction of natural environment, hence conservation of plant genetic resources is of utmost importance to mankind. Conventional ex situ maintenance is prone to natural catastrophes, diseases and attacks from pests. It is also costly and requires larger area of land. In vitro conservation refers to the maintenance of germplasm in a stable artificial environment under defined nutrient condition. Miniaturization of explants allows to reduce space requirement and subsequent labor cost for maintenance of germplasm collections. The in vitro storage methods discussed in the book circumvent the problems of ex situ maintenance of recalcitrant seed species and vegetatively propagated crops.