Improvement of growth parameters of prune callus cultures destined to initiate cell suspensions

Callus was inducted on wounded leaf explants from shoot tips of a particular Prunus domestica 'Węgierka Zwykła' clone cultivated in vitro. The improvement of Sweet Common Prune stock callus tissue parameters has been approached by experiments on culture protocols. Either for the induction or maintenance of tissue modified Murashige and Skoog medium, supplemented with different auxins and cytokinins at varying concentrations, was used. The goal was to obtain the highiest possible proliferative capacity of friable tissue without any signs of cell redifferentiation for about 10 weeks. The choice of auxin was an important factor regulating the rate and kind of tissue growth, and for the examined prune clone auxin alone brought a relatively small proportion of cells into division, so advantageous was to combine it with oxygenated cytokinin. Friable tissue was obtained on media supplemented with dicamba or with picloram, but not with 2.4-D neither alone nor combinated with IBA.