Lettuce seeds treated with cerium and lanthanum aqueous solutions

Rare earth elements, or lanthanides, are important for plant growth and can benefit seeds vigor and germination, when incorporated to the seeds treatment. Thus, this study aimed at evaluating the initial performance of lettuce seeds submitted to treatments with cerium (Ce) and lanthanum (La), as well as their absorption. For this, lettuce seeds (Regina cultivar) were immersed in aqueous solutions of Ce or La, in different experiments, at the Ce concentrations of 0.0 mg L-1, 5.0 mg L-1, 10.0 mg L-1, 15.0 mg L-1, 20.0 mg L-1 and 25.0 mg L-1, and at the La concentrations of 0.0 mg L-1, 2.0 mg L-1, 6.0 mg L-1, 12.0 mg L-1, 20.0 mg L-1 and 30.0 mg L-1, for one hour. Tests for germination, first germination count, seedling dry weight and total, root and shoot lengths were carried out. The amount of Ce and La absorbed by seeds and seedlings were also evaluated. It was concluded that the treatment of seeds with Ce and La did not increase seeds germination, but stimulated seedlings growth. When these elements are applied to lettuce seeds as aqueous solution, they are absorbed by seeds and transferred to seedlings.