Enhancing salinity tolerance in tomatoes at the reproductive stage by increasing pollen viability

Abstract

This study was conducted to mitigate the adverse effects of sodium chloride stress on the reproductive parameters of tomatoes. This experiment was conducted in the greenhouse of the laboratory of tropical horticultural science, department of International agricultural development, Tokyo University of Agriculture. The design was a factorial CRD (completely randomized design) with five sodium chloride (0 mM, 50 mM, 100 mM, 150 mM, and 200 mM) treatments and four primings (0 MPa, 0.4 MPa, 0.8 MPa, and 1.2 MPa) treatments. Micro-Tom seeds were soaked in polyethylene glycol (PEG6000). Salinity was applied through irrigation water when the first flower bloomed. Reproductive-related parameters such as the number of flowers per plant, pollen viability, pollen germination, pollen tube length, number of fruits per plant, fruits size and yield per plant were measured. It was observed that salinity affected the tomato plants severely during the flowering stage, and many flowers did not bear fruit due to the decrease in pollen viability. In addition, electrolyte leakage increased under salt stress, while priming decreased this parameter. Priming improved the number of flowers, pollen viability, and fruits per plant. The best priming treatments were 0.8 MPa and 1.2 MPa for promoting and enhancing tolerance in the reproductive stage. Keywords: physiology, priming, pollen viability, reproductive stage, and salinity.