The explant should be selected as apical tip or bud. This region is composed of meristematic tissues. These cells are in a rapid deciding phase and hence y are not infected by any bacterial or viral agent. These tissues help in development of disease-free plants. 

Tissue culture is a biological technique which involves development of plant under controlled condition on a nutrient culture medium of known composition.

Biofortification is method in which food is added or supplemented with required nutrients. This process can be used for production of staple crops with higher levels of essential nutrients. This can be done eir through selective breeding or genetic modifications. The staple crops like wheat are fortified with zinc and golden rice, rice is fortified to produce beta-carotene. The rural areas generally feed on staple crops and suffer from nutrient deficiency. The consumption of this fortified crops will prevent deficiency disorders and improve health of people in rural areas.