In biology, a propagule is any material that functions in propagating an organism to the next stage in its life cycle, such as by dispersal.
Propagules are produced by organisms such as plants (in the form of seeds or spores), fungi (in the form of spores), and bacteria (for example endospores or microbial cysts).
These can refer to bacteria, viruses, fungi, or protists, and can be contained within host material.
[2][3][4] For instance, for influenza, the infectious propagules are carried in droplets of host saliva or mucus that are expelled during coughing or sneezing.
In micropropagation, a type of asexual reproduction, any part of the plant may be used, though it is usually a highly meristematic part such as root and stem ends or buds.