MICROPROPAGATION OF PHALAENOPSIS-HYBRIDS IN TEMPORARY IMMERSION SYSTEM (TIS) - EFFECTS OF EXUDATED PHENOLIC SUBSTANCES ON PLANT DEVELOPMENT

摘要

During commercial in vitro culture phenolic compounds are often removed from culture media by activated charcoal or other substances binding phenolic compounds to avoid negative effects on plant growth. In order to elucidate this aspect, we evaluated the effect of PVPP - a substance well known for binding phenolic compounds - during the in vitro-development of the Phalaenopsis-hybrids shoots. For this purpose, the liquid medium was supplemented with PVPP to bind the exudated phenolic substances during the culture. Control shoots were cultivated in liquid medium without PVPP. The phenolic substances from shoots and media were extracted with ethylacetate and separated via HPLC. Phenolic compounds, extracted from liquid media and plants, revealed the same peak-pattern after HPLC-separation, while the concentration of these compounds in the plant tissues varied. The concentration of phenolic compounds of shoots was higher than of leafs. Removing the phenolic substances from the liquid media during the culture period reduced biomass production and shoot multiplication rate. Additionally, binding the phenolic compounds to PVPP was associated with morphological changes. Shoots grown without phenolic compounds in liquid media showed larger leaf areas compared to control plants. Cultivation of Phalaenopsis-hybrids in TIS enhances the biomass production and multiplication rates compared to semi solid media. We have shown that exudated phenolic compounds have no negative effect on biomass production and propagation rates. In contrast these results indicated a vital role of the substances within the developmental processes during shoot multiplication.