ABSTRACT

Two very simple, but reliable, micropropagation techniques can be demonstrated using potato. The rst technique, called single node or multiple node culture, involves production of shoots from cultured single or multiple nodes (in vitro layering) positioned horizontally on the medium. In potato, the initial sources of these nodes are SPT shoots established in vitro from meristem tips (Figure 12.1). Interestingly, potato cannot be multiplied by using the shoot tip culture method (see Chapter 12) because axillary shoot proliferation is not usually promoted by the addition of cytokinin to the medium. Typically, single elongated unbranched shoots comprising multiple nodes are rapidly produced. These shoots (microcuttings) are either rooted and acclimatized to eld conditions or are subdivided into single node cuttings to initiate additional cultures (Figure 15.1). Although not the most efcient method, node culture is the most reliable micropropagation procedure to produce plants that are true to type.