A non caloric sweetener stevia rebaudiana bertoni - tissue cultured plantlets for organic farming and home gardening

The paper presents the optimization process of obtaining plantlets of Stevia rebaudiana under in vitro culture conditions and describes the method for adjusting the rooted plants to ex vitro conditions. The low viability of seeds and poor germination are the reasons of difficulties in commercial cultivation of this species in Poland. Plant tissue and cell cultures are the techniques helping to overcome these limitations. Numerous shoots were obtained using sterile nodal segments that were cultured on solidified MS media and supplemented with phytohormones. Elongated shoots were transferred onto the rooting medium. Thus in vitro regenerated plantlets were acclimated to greenhouse conditions. The highest efficiency of shoots proliferation was observed at presence of 0.5 mg dm-3 BAP. The longest stems and the largest number of leaves and the greatest width of leaf were observed when 0.5 mg dm-3 GA3 was applied into medium. The process of rhizogenesis was intensified by the 0.5 mg dm-3 IBA contained in the nutrient medium. Under the influence of this phytohormone roots were the most numerous and the longest. At the stage of acclimatization 1/4 MS salt solution was used for irrigation of plantlets what supports increased of the process from 46% to 70% in comparison ...

CULTIVATION OF SOAPWORT PLANTS (SAPONARIA OFFICINALIS L.) IN IN VITRO CULTURES

Saponaria officinalis L. is a medicinal plant from the family Caryophyllaceae. It occurs in most European countries, as well as in North Africa, America and Western Asia. The aim of the study was to find an optimal method of sterilization S. officinalis seeds in order to obtain sterile seedlings and to multiply axillary shoots from nodal explants isolated from them, on MS medium with the addition of growth regulators (RW). In this study, 4 variants of seed sterilization were compared using NaClO at the following concentrations: 1.5% (2), 2% (3) and 2.5% (4) for a period of 11 minutes. The control was a variant in which 70% C2H5OH was used for pre-sterilization for 1 minute (1). The highest percentage of sprouted, seeds and sterile seedlings and the lowest percentage of contamination were obtained in variant (4). As a result of micropropagation of soapwort in in vitro cultures, axillary shoots were formed from nodal explants from axillary buds. The highest percentage of explants with shoots (95%) and callus tissue (48%) and the highest number of shoots from one explant (5.95) were obtained in the second passage on MS medium with the addition of 4 mg.dm-3 BAP and 0.5 mg.dm-3 NAA. ...