The application of hierarchical cluster analysis for clasifying horseradish genotypes (Armoracia rusticana L.) roots
Keywords:horseradish, genotype, total phenols, DPPH, hierarchical cluster analysis
Horseradish (Armoracia rusticana L.) is a perennial herb belonging to the Brassicaceae family; it contains biologically active substances such as phenolic compounds.
The aim of the present research was to clasify horseradish root genotypes, based on the total phenol content and antioxidant properties, using the hierarchical cluster analysis (HCA), and to compare them with clusters obtained from data of the molecular random amplified polymorphic DNA (RAPD) analysis.
Plant phenolic compounds are among the most important primary antioxidants. The phenolic composition of plants is affected by different factors such as variety, genotype, climate, harvest time, storage, processing. Nine genotypes of horseradish roots harvested at three different times in the period from August to November 2011 were used. Several statistical methods can be used to assess differences in the horseradish genotypes. Using a univariate statistical analysis and standard deviations for each analyzed variable does not help to get a complete insight into the complex analysis. Multivariate statistical methods are appropriate tools for the analysis of a complex data matrix. The hierarchical cluster analysis (HCA) used in the current research is a simple way of grouping the set of available data by their similarities according to a set of selected variables. No similarities were found by clustering the genotypes according to the content of biologically active compounds and molecular analyses.