Evaluation of the Fermented Extract of Sargassum spp., for the Biostimulation in the Germination of Tomato Seeds and Seedlings (Solanum lycopersicum L.)

The species Sargassum spp., is a macroalgae that in recent years has become a problem on the coasts of the Mexican Caribbean and Florida in the United States. Derived from its chemical composition, Sargassum spp., could be used as a microbial substrate to obtain a bioextract with a greater amount of bioactive compounds, which will improve the germination of tomato seeds. In this work, Sargassum collected from the Mexican Caribbean was used. The collected sample was divided into washed Sargassum and natural Sargassum, to serve as a substrate in a liquid fermentation process using a strain of Aspergillus niger. The fermented extract was collected, analyzed, and applied in germination bioassays on tomato seeds. The washed Sargassum bioextracts showed increases in the content of protein, sugars, phenols, flavonoids, and tannins, being twice as high as the content of the unwashed Sargassum extract. On the other hand, the use of a high dose (1:1) of unwashed Sargassum bioextract increased the percentage of germination per day, the final percentage of germination, the seedling vigor index, seedling height, and fresh biomass. The treatment of seeds with ferment extracts from both Sargassum types, improves germination parameters, and promotes the development of tomato seedlings.