Horseradish (Armoracia rusticana G. Gaertn., B. Mey. & Scherb.) cultivated in Trentino-Alto Adige (northern Italy) characterized by biometric traits and glucosinolate content

Abstract

Horseradish is a crop grown for its edible underground parts. The development of new cultivars is hindered by the species' predominant vegetative reproduction, making it essential to evaluate locally cultivated accessions to identify new types suitable for cultivation. To this end, 11 horseradish accessions from family vegetable gardens in Trentino-Alto Adige, Italy were examined using 26 qualitative and six quantitative morphological descriptors and characterized by the five major glucosinolates (GSLs) present in the rhizome compared to a reference cultivar. A wide range of variability was observed for the considered qualitative morphological traits. The rhizome's top and basal diameters were 9.9 and 6.2 cm, respectively, with an average fresh weight of 521 g. Total GSL content ranged between 79.5 and 133.5 μmol/g dry weight (DW), with sinigrin (SIN) being the primary component at an average content of 110.0 μmol/g DW. Differences among the investigated accessions were noted for quantitative traits describing their productive features and for GSL content. A positive correlation was discovered between the biometric traits of the plant's underground parts and the SIN and total GSL content, suggesting a link between the quality and yield of the edible product. According to the multivariate analysis, accessions were grouped into three main clusters: the largest of the reference cultivar and the majority of accessions with similar productive and qualitative traits; another featuring two with good qualitative and productive characteristics. The investigated accessions proved to be a valuable germplasm source for cultivating the species.