Establishment of calli and suspension cultures

Abstract

Publisher Summary A plant callus is a wound response from an explant (the fragment of a plant or tissue used to initiate a culture) consisting of unorganized, dividing cells. Cellular proliferation can also be produced in vitro without physical injury or wounding by germinating seeds on a medium containing a plant growth regulator. Individual cells in a callus mass can vary in size, shape, pigmentation, and appearance. Most are differentiated cells with a large central vacuole and nucleus to one side as opposed to undifferentiated, meristematic cells that are isodiametric, small, lack a prominent vacuole, are cytoplasmic, and have a large central nucleus. The callus cultures are used for the studies of cell division, morphogenesis, secondary product synthesis, bioassays for plant growth regulators, and more recently for selection, mutation, and genetic modification at the cellular level. The major considerations for callus and suspension culture initiation are selection of explant, medium, and culture conditions. The explant used to initiate the culture can be derived from any piece of the vegetative or flowering plant. The culture environment can be modified in photoperiod, light quality and intensity, and temperature.