Produção e qualidade de frutos de tomate em função da aplicação de zinco e selênio

Abstract

Selenium (Se) and zinc (Zn) deficiency in the population represents a challenge for global health, constituting a significant form of human malnutrition. In this context, biofortification of basic foods with micronutrients appears as an effective strategy to increase the nutrient content in foods, thus combating malnutrition. Plants play a crucial role in the bioaccumulation of Zn and Se in food chains. Thus, considering the widespread consumption and various benefits to human health resulting from regular consumption of tomatoes, this vegetable becomes a strategic crop in biofortification studies. In the present study, three experiments were carried out under greenhouse conditions with the following objectives: (i) to evaluate the effect of applying Se and Zn, separately, via soil, on tomato production and on the nutrient and Se content in the shoots and in the fruits; and (ii) to evaluate the effect of simultaneous application of Se and Zn on tomato production and quality. In the third experiment, the fruits were evaluated regarding the number of fruits per plant, fruit weight, yield, diameter, length, color, and

firmness parameters. In addition, pH, total soluble solids, titratable acidity, lycopene, β- carotene, vitamin C, total phenolics, total flavonoids, total anthocyanins, and nutrient and Se

composition, were analyzed. The results of the first two experiments showed that the application of Se and Zn increased the levels of these elements in the shoots and fruits. Furthermore, Se increased the levels of N, S, Fe, and Mn, but doses greater than 100 μg dm-3 caused phytotoxicity in plants. On the other hand, the application of Zn reduced the levels of P, K, Ca, and Fe. Therefore, low doses of Se are preferable, as they provide an adequate amount of Se without compromising tomato yield, while new studies are needed to increase the Zn content in the fruits. The results of the third experiment showed an increase in fruit mass with the application of Se associated with 4 mg dm-3

of Zn, which contributed to greater yield. Furthermore, the supply of Se and Zn increased the levels of β-carotene, vitamin C, total flavonoids, and total anthocyanins, in addition to increasing the levels of Se, Zn, N, and Cu in the fruits. These results indicate that simultaneous biofortification with Se and Zn has great potential to improve tomato quality. The addition of Se is important to enrich the fruits, due to the low availability of this element in the soil, while the dose of Zn must be adjusted according to the specific purpose.