Tomato Halopriming for Improving Germination and Seedling Growth under Normal and Saline Conditions

This study was carried out to investigate the effects of halopriming on germination and seedling growth of tomato cv. Ace 55VF seeds under normal and saline conditions. Halopriming was done by exposing seeds to aerated solutions of NaCl (0.05 M and 6M) and KNO₃ (25mM and 2%). There was no significant effect of halopriming treatments on germination percentage, however, halopriming had a significant effect on germination rate and mean germination time. Halopriming with 2% KNO₃ increased germination rate and decreased mean germination time. Also, the 2% KNO₃ halopriming treatment had the highest significant values for No of leaves, stem length and diameter, fresh and dry weights of shoot and root, and leaf chlorophyll content. In general, KNO₃ halopriming treatments had a positive effect on germination and seedling growth as compared to NaCl halopriming. Under saline conditions, halopriming increased final germination percentage and improved seedling growth compared to unprimed treatment. NaCl halopriming treatment increased adaptation of seedlings to salt tolerance compared to control treatment (unpriming) followed by KNO₃ halopriming treatment. However, final germination percentage was highest significantly with KNO₃ halopriming. Therefore, it can be said that the germination and seedling growth of tomato are improved by halopriming treatments, especially with KNO₃, under normal and saline conditions.