In vitro induction of axillary potato microtubers and improvement of their quality

Germinated tubers of selected cultivars Kera, Resy, Nicola and Oreb were made healthier by heat treatment. They were derived from germ explants on MS media with the addition of BAP 1 mg 1^-1 and IAA 0.2 mg 1⁻¹. After sufficient multiplication of stems, optimum conditions of the photoperiod were followed for the induction of axillary microtubers on stem segments in media with BAP 10 mg 1^-1 and 8% sucrose. The ability of tuberization is different: the early cvs. Kera and Resy induce earlier tubers at a long photoperiod and late cvs. Nicola and Oreb tuber rather at a short photoperiod. In suitable photoperiods the inhibitory substances accelerate the induction of axillary tubers and limit the formation of adventitious roots. Synthetic inhibitors applied in induction media increase the number of the tubers. The quality of tubers was affected by the addition of a mixture of amino acids: aspartic, glutamic, lysine and proline in concentrations of 12.5, 25 and 50 mg.1^-1 into the induction media. In the course of cultivation the types which were growing well, formed tubers and increased the volume were selected. The representation of amino acids in the tubers was not significantly affected, there was only an increase in proline. The higher content of amino acids was reflected in the increase of proteins in the tubers. The selected clones are further multiplied.