Screening for Variation in Leaf Elemental Content Between Croatian Autochthonous Kale (Brassica oleracea L. var. acephala) Accessions

Kale (Brassica oleracea L. var. acephala) has a long history of cultivation, and its importance as a source of mineral nutrients has received particular attention. This study aims to screen the variation in elemental leaf accumulation of 23 Croatian autochthonous kale accessions from the Adriatic basin. A two-factorial experiment with harvest time and kale accession as the main factors was conducted under field conditions. Further, the leaf elemental contents were measured and inter-elemental correlations computed. An analysis of the data revealed that IPT 418 accumulated the highest contents of Ca, Ni, and Li, while IPT 401 was most effective in Mg and Zn accumulation. The accessions IPT 411, IPT 384, and IPT 390 had the highest amounts of P, Mn, and Cr, respectively. Considering the range within the highest and lowest content, the accumulation varied 4-fold for Ca; 1.8-fold for Mg; 1.5-fold for P; 1.5-fold for Mn; 2.5-fold for Ni; 2-fold for Zn; 2.2-fold for Cr; and 1.7-fold for Li. According to the correlation matrix, positive correlations in elemental phytoaccumulation were found between macro- and micronutrients, while negative correlations were observed among macronutrients in most cases. In conclusion, the accessions most efficient in accumulating macro- and micronutrients may be potentially used to address nutrient malnutrition and produce more nutritional kale.