STUDYING BIODIVERSITY OF HOP (HUMULUS LUPULUS L.) ACCESSIONS FROM THE COMPOSITION OF THEIR ESSENTIAL OILS
The composition of the essential oil for a given accession varies very little from year to year, but varies widely (i.e. is characteristically different) for different accessions. Thus, one can conclude, that the composition of hop essential oil depends very much on the genotype. As we wanted to observe all possible genetic variability, not only modern, but especially old accessions were included in the study. GC data are widely used to characterise hop accessions and different components have been considered important by various authors (Kenny, 1988).
Objective dealing with chemometric data on complex biotic samples as e. g. hop (Humulus lupulus L.) essential oil is quite demanding first from the chemical point of view (essential oil contains more than 300 components, many of them in trace amounts which are quite a challenge to determine with the accuracy and precision needed) and then from the modelling point of view, namely to deal with this waste amount of data and to consider not too many and not too few values. Too few means losing information and poor differentiation between the samples and too many make the pattern less transparent or even non recognisable. Various routine statistical methods are used to select the relevant data (multivariate analysis, rotational factor analysis etc.)