A two-year study of garden cress (Lepidium sativum L.) was conducted, evaluating 81 foreign (from the Genebank Department of Leibniz Institute of Plant Genetics and Crop Plant Research (IPK; Institut für Pflanzengenetik und Kulturpflanzenforschung) in Gatersleben, Germany) and Iranian (local cultivars) genotypes for seed yield and 18 traits. The first two principal components of the genotype × trait interaction biplot accounted for 70% and 61% of the total genotype × trait interaction for the years 2012 and 2013, respectively. The vertex genotypes for the first year were G23, G59, G61, G51, G6, and G12 and for the second year were G32, G78, G53, and G20. Traits, such as seed yield and biological yield, were favorable in sectors of G32 and G12 and these vertex genotypes fell in the same sectors in both years. A positive association was observed between plant height and biological yield, as well as between the main stem axis and seed yield in both years as indicated by the acute angles. Based on seed yield, Genotype G6 was the best followed by Genotypes G29, G32, G48, and G50 in the first year and Genotype G32 followed by Genotypes G29 and G42 were the best genotypes in the second year. Given the importance of main axis length, biological yield, plant height, and flowering period regarding seed yield in this and previous investigations, these traits should be selected in garden cress.
