Variation in growth traits and biological activities among wild watercress (Nasturtium officinale L.) populations in Iran

Watercress (Nasturtium officinale L.), a cruciferous vegetable, is ranked as a superfood among vegetables and fruits due to the high level of micro/macro elements, vitamins, and phytochemicals that led to an increase in its consumption in the human diet. In the present study, eleven wild N. officinale populations (NOP1-NOP11) collected from different locations in Iran were evaluated regarding agro-morphological, nutritional values, and biological activity. A significant variation in phenotypic and phytonutrient traits was observed among the studied populations. Pahneh Kola (NOP₈) exhibited the most significant values in terms of plant height (12.33 cm), number of nodes (12.00), root length (28.57 cm), and dry weight (0.96 g), indicating a strong performance in these growth parameters. The concentrations of vitamins B₃ and B₆ varied among the studied populations ranging from 0.25 µg/ml to 6.25 µg/ml and 1.9527 to 44.58 µg/ml, respectively. The highest chicoric and ferulic acids content was measured in Pahneh Kola (NOP₈) (4.33 mg/g DW) and Kharajgil (NOP₅) (7.16 mg/g DW), respectively. The outstanding antioxidant activity of the plant extracts was observed among populations, especially for Kharajgil (NOP₅). The plant extracts showed remarkable antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC values ranging from 16 to 64 mg/ml. This research was conducted to characterize diversity and select promising wild populations for cultivation. The observed diversity constructs the basis of future exploitation and breeding programs of this valuable vegetable.