Abstract The aim of the study was to determine the effect of exogenous sucrose and cytokinin on ethylene production and responsiveness in relation to the shoot formation of Pelargonium × hortorum ‘Bergpalais’ in vitro. Increasing the concentration of sucrose from 15 to 40 g L−1 in medium containing meta-topolin (mT) resulted in a two-fold decrease in the number of shoots and leaves as well as a reduction in ethylene production. The addition of ethylene synthesis inhibitor (AVG) to mT-medium significantly reduced the ethylene production and the shoot growth, but it had no significant influence on the shoot formation. The mT-induced shoot formation was, however, significantly reduced in the presence of ethylene action inhibitor (AgNO3), in a manner dependent on sucrose levels. At the end of the subculture period, increased sucrose concentrations (15–40 g L−1) in the presence of mT and AgNO3 resulted in a 3.7-fold increase in ethylene emission. At the same time, the supply of sucrose caused a 2.8-fold increase in the level of endogenous abscisic acid (ABA). Our results may suggest that the inhibitory effect of high sucrose concentration (30 and 40 g L−1) may depend on its influence on ethylene sensitivity. It also suggests that sucrose-regulation of the shoot formation of Pelargonium in vitro is mediated by ABA.

Rumex thyrsiflorus Fingerh. is mentioned as a European folk medicinal plant. This species has also been traditionally used as an edible plant in Eastern Europe because of its nutritional value. During the study, qualitative and quantitative sex-related differences of phenolic constituents in methanolic leaf extracts of R. thyrsiflorus were evaluated. The presence of the same substances (nine phenolic acids before, and six phenolic acids after acid hydrolysis, nine flavonoids, and a catechin) was estimated in both female and male specimens, using the HPLC-DAD method. A statistically significant higher content of eleven constituents in female plant extracts (acids: chlorogenic, p-coumaric, cryptochlorogenic, gallic, protocatechuic, neochlorogenic, vanillic; flavonoids: quercitrin, rhamnetin, rutoside; and catechin) was shown. This is the first report concerning the relation between the sex and the content of biologically active phenolic secondary metabolites in leaf extracts of R. thyrsiflorus. Female plants of R. thyrsiflorus could be useful for pharmaceutical purposes as a preferential source of bioactive phenolic acids, flavonoids and especially catechin.