Potato microtubers as research tools: A review

Although in vitro production of potato tubers or microtuberization was achi eved more than 40 years ago, the application of microtubers in reliable mod el research systems has been slow to develop. Several factors such as the u se of growth regulators in microtuber induction and growth media, the mixot ropic nature of the in vitro system, and cultivar-specific responses have l ed to interpretive difficulties. A cautionary note is also necessary in vie w of apparent growth and development differences, metabolic alterations, an d somaclonal variation encountered in microtubers that may not be found in field-grown tubers. Evidence for strong and consistent analogies between mi crotubers and field-grown tubers for their induction, growth and developmen t, and metabolism often is lacking. However, several components such as the rapid and near-synchronous induction and growth, which can be modified by a range of exogenous compounds or conditions, make the microtuber a valuabl e model system. Complex problems such as dormancy also appear to be particu larly amenable to examination by the microtuber system. In addition, the us e of microtubers as experimental research tools has potential in the areas of plant metabolism, germplasm selection and evaluation, genetic transforma tion, somatic hybridization, and molecular fanning.