Characterization of a new dwarf watercress (Nasturtium officinale R Br.) ‘Boldrewood’ in commercial trials reveals a consistent increase in chemopreventive properties in a longer-grown crop

We describe ‘Boldrewood’, a new accession of watercress ( Nasturtium officinale R. Br.) that was initially found to be of short stature with high antioxidant capacity (Payne et al. 2015). This was of particular commercial interest because it offered the potential to develop a novel watercress product with fork-friendly size and improved health-benefits. In two commercial trials comparing Boldrewood to a control, we confirmed that Boldrewood exhibits a dwarf phenotype with a significantly shorter stem and consistently produced more leaves per stem area alongside comparable crop biomass. The antioxidant and chemopreventive capacity of Boldrewood were comparable to the commercial crop. For the first time, we observed a novel increase in glucosinolate concentrations and cytotoxicity to cancer cells, characterised as decreased IC 50 (half-maximal concentration of an inhibitor), associated with increased crop age at harvest. This suggests that a slower-growing and longer to harvest crop provides a significant improvement in health benefits gained in this leafy crop which is already known to be highly nutrient dense and with considerable chemopreventive ability.