Response of sunflower seeds (Helianthus annuus L.) to different concentrations of metals and doses of gamma radiation (241Am)

Abstract

The sunflower crop (Helianthus annuus L.) presents great tolerance to heavy metals and in pre-determined doses of gamma (γ) radiation it presents gains in plant increments. This study aimed to evaluate the response to doses of γ radiation and different concentrations of toxic metals in the vegetative development of sunflower. Mirasol sunflower seeds were subjected to different doses of 241Am γ rays and concentrations of Aluminum, Cerium and Copper (mg L-1). Sunflower plants were evaluated only in the vegetative period for germination, aerial length, root length, aerial and root fresh mass, aerial and root dry mass. The doses of γ radiation promoted increases in the variables in the vegetative phase, especially for 5 and 10 minutes of exposure to γ rays. The concentrations of the toxic elements Al and Ce showed significant differences in all increments, however, doses higher than 85 mg L-1 demonstrated losses in length and mass of sunflower plants. For the Cu element, the doses did not have a significant effect, these being non-significant and the cultivar Mirasol resistant. Future studies should be carried out evaluating the reproductive phase and its gains in increasing biomass and production.