Effect of halopriming on germination and seedling vigor of tomato

Abstract

The study was carried out to investigate the effects of halopriming on germination, seedling growth and biochemical responses of tomato seeds. Priming was done by exposing seeds of two tomato cultivars ‘Nagina’ and ‘Pakit’ to aerated solutions of 10, 25 and 50 mM NaCl and KNO3 for 24 h. Halopriming with 25 mM KNO3 increased final germination percentage, germination index, root length, shoot length and seedling fresh weight of both tomato cultivars as compared to all presowing seed treatments including control. Seeds of both tomato cultivars primed with 25 mM KNO3 for 24 h, significantly reduced the time taken to 50% emergence and mean emergence, increased final seedling emergence percentage and seedling growth. Results indicated that halopriming with varying concentrations of KNO3 improved germination potential and seedling establishment of both cultivars and it proved better option than NaCl which resulted in poor emergence and seedling growth. Maximum improvement was recorded in seeds primed with 25 mM KNO3. The better performance of haloprimed seeds may be due to lower electrical conductivity (EC) of seed leachates, higher total and reducing sugars along with increased α-amylase activity.   Key words: Seed dormancy, α-amylase, halopriming, electrical conductivity, reducing sugars.