| heal.abstract |
We initiated callus cultures of mistletoe (Viscum album L.) by inoculating leaf and stem explants on a Murashige and Skoog (MS) medium supplemented with different combinations of growth regulators at various concentrations. The cultures were assayed for the accumulation of K, P, Ca and Mg. The accumulation of all macronutrients was significantly affected by both growth regulator treatment and explant source, as well as their interaction. For stem-derived calli, application of 4.65 μM Kin was superior to other PGR treatments leading to the maximum in vitro accumulation of the selected macronutrients. In addition, the average accumulation in vitro was higher in stem-derived callus cultures than in leaf-derived calli. Potassium, P and Ca accumulation in vitro was lower than in mistletoe plants and lower than in mistletoe hosts, such as fir, oak and chestnut. Mistletoe plants were able to accumulate K at a larger concentration than host species. Except for Ca, accumulation of macronutrients in stem-derived callus cultures was highly correlated with dry weight concentration. A high positive correlation was also observed among K, P and Mg concentration, while Ca accumulation was relatively high and positive correlated with Mg. On the contrary, in leaf-derived cultures a relatively high positive correlation was observed only between K and Mg concentration. The addition of ascorbic acid to the culture medium affected significantly the accumulation of P and Ca in stem-derived calli and the accumulation of K and Mg in leaf-derived calli. However, Ca concentration in leaf-derived calli and Mg concentration in stem-derived calli was decreased after ascorbic acid addition. Finally, the concentration of the selected macronutrients fluctuated during a total incubation period of ten weeks on MS + 4.95 μM NAA, with an increasing trend after the eighth week. Results are discussed in view of the possible metabolic pathways requiring the studied macronutrients, as well as improving culture of mistletoe in vitro. © 2002 Elsevier Science B.V. All rights reserved. |
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