Stimulation of development of Cucumis sativus L. plants by low concentration of aluminium in vitro conditions

The culture of cucumber plants Cucumis sativus L. Wisconsin cultivar, from seeds and leaf explants, were carried out on the basic medium ofMurashige and Skoog in vitro conditions. In the culture set from the leaf explants the MS medium was supplemented with IAA (0,5 mg/dm3) and BAP (2 mg/dm3). Aluminium (as AlCl3) was added to the media in concentration Of 1 mg/dm3. The media pH was adjusted to 6,2 or 4,2. In seedling culture, aluminium substantially stimulated the growth and development of the root system while a shoot to a small degree only (it advanced leaf formation mainly), causing no morphological and developmental anomalies. In the culture from the leaf explants Al induced the process of rhizogenesis which did not take place on the media without Al. It also stimulated a shoot morphogenesis. After 8 weeks of culture, 32 % leafexplants formed plants with short shoots (2-3,5 cm), long ones (5,5-7 cm) and with long but poorly branched root system„ In the acid conditions (pH 4,2), the effect 0 Al on plant growth was Iower than on the media with pH 6,2. Also a number of regenerated explants with comparable direction of differentiation won a fewer in low pH