Evaluation of Ascophyllum nodosum and Sargassum spp. Seaweed Extracts’ Effect on Germination of Tomato Under Salinity Stress

Abiotic stresses like salinity are proven to be crucial limiting factors in the seed germination of many plant species and the later establishment of cultivation regarding plant growth, yield and fruit quality. Therefore, there is a pressing need to find practices and materials to enhance abiotic stress tolerance from early stages such as germination so that plants can overcome these stresses as soon as possible. A total of six treatments of seaweed extracts [1, 2 and 3% of Algit Super (Ascophyllum nodosum) and Alga 300 (Sargassum spp.)] and three controls were tested, with 20 seeds per replication soaked in each extract concentration for 15′; four replications were carried out per treatment and seeds were placed on Petri dishes in the dark. Speed and percentage of germination, vigor index I and II, dry weight and average lengths of roots and shoots were evaluated under 75 mM NaCl stress. All treatments positively affected all parameters evaluated, whether significant or not. Results indicate that soaking tomato seeds in seaweed extracts of various concentrations led to a significantly increased speed and percentage of germination, vigor index I and II, dry weight and average lengths of roots and shoots. The best combination of concentration and seaweed species is concluded to be 2% Sargassum spp. for all parameters evaluated.