In vitro culture of potato

The cultivated potato (Solanum tuberosum) is a crop of considerable impor­tance, ranking fourth in world production after wheat, rice and maize. It is thus the most important dicotyledonous crop species, and the most important tuber crop. There are seven cultivated species of potato, which range in chromosome numbers from diploid (24 chromosomes) to triploid, tetraploid and pentaploid. S. tuberosum subspecies tuberosum is normally regarded as the cultivated potato, and is the most widely grown; cultivation of subspecies andigena is restricted to the Andes region of S. America. In addition to the seven cultivated species, there are documented a further 228 wild species. Thus there is a wide gene pool of genetic diversity (Hawkes, 1990)