Physiological and antioxidant responses of cape gooseberry (Physalis peruviana L.) seedlings to phosphorus deficiency

Abstract

The main objective of present study was to understand the physiological effects of phosphorus (P) deficiency and the antioxidant response in cape gooseberry (Physalis peruviana L.) seedlings. Seedlings were grown in soil with five P levels: 0 (P0), 6 (P6), 12 (P12), 25 (P25) and 50 (P50) mg of P2O5 kg-1. The plant growth, gas exchange, chlorophyll content, membrane integrity and the antioxidant response in cape gooseberry were evaluated. In the P0, P6, P12 treatments, the seedlings showed a reduction in total biomass, the number of leaves, leaf area, root length density, shoot/root ratio, photosynthesis, transpiration, stomatal conductance, and chlorophyll content, as well as an increase in the electrolyte leakage, the proline content and the activity of catalase and peroxidase compared with the P50 treatment. The P25 treatment was not different compared to P50 in terms of photosynthesis, chlorophyll content and total biomass after 30 d of treatment, the number of leaves and root length density at 90 d of treatment, and in electrolyte leakage and peroxidase activity at 60 and 90 d of treatment. Doses below 25 mg of P2O5 kg-1 cause P deficiency in cape gooseberry seedlings, inducing antioxidant and protection response mechanisms to cope with stress.