Ameliorate the cadmium toxicity in Solanum tuberosum L. plants with selenium and silicon application

The present study aimed to prove the efficiency of Se or Si as relievers of the Cd toxicity in potato plants. Solanum tuberosum plants, Asterix genotype, from in vitro propagation were placed in pots with sand and irrigated with complete nutrient solution for 60 days under six treatments: T1: Control (nutrient solution); T2: 2.5 µM Se; T3: 2.5 mM Si; T4: 50 µM Cd; T5: 50 µM Cd + 2.5 µM Se; T6: 50µM Cd + 2.5 mM Si. The treatments were arranged in completely randomized design, with four replicates for each treatment and six plants per replicate. The plants were collected at 30 and 60 days after application of the treatments. Cadmium was highly toxic in all parameters (dry and fresh weight, plant height, leaf number, leaf area, root and photosynthetic parameters), in both assessments. However, Se and Si were effective in mitigating Cd toxicity in all parameters, although Si has been shown to be more efficient than Se in dry weight and plant height parameters. Thus, from data obtained in this study, it is clear that the beneficial elements tested have power to ameliorate Cd toxicity

Growth of potato genotypes under different silicon concentrations

The aim of this work was to verify the beneficial potential of Siliconon the growth of potato genotypes in order to select potato genotypes that best respond to Si application. Four potato genotypes were used: SMIJ319-7, Dakota Rose, SMIF212-3 and SMINIA793101, grown in hydroponic system. The plants were transferred to nutrient solutions with four Si concentrations: 0; 0.5; 2.5; and 5.0 mM as NaSiO3. After seven days of exposure to treatments, leaf area, leaf number, shoot length, and fresh and dry weight of roots, stem and leaves were determined. The application of 0.5 mM Si promoted an increase in growth parameters of plants used in this work, mainly in leaf area, leaf number,and leaf and stem dry weight. However, the application of higher concentrations of Si (2.5 mM) promoted reduction in the growth parameters, mainly in leaf area. It was also possible to observe a genotypic variation with respect to Si, SMIJ319-7 and SMIF212-3 genotypes being the most responsive to Si. Therefore, the concentration of 0.5 mM Si is considered optimal for potentiating the growth of potato plants, and SMIJ319-7 and SMIF212-3 genotypes are the most responsive to Si

Susceptibility to weathering damage and oxidative stress on soybean seeds with different lignin contents in the seed coat

Abstract: This study aimed at evaluating the relationship among lignin content in the seed coat of soybean seeds with tolerance to weathering damage and oxidative stress. Four soybean cultivars (CD 208, CD 215, CD 202 and BRS 184), with lignin contents in the seed coat of 4.2, 2.6, 2.0 and 1.7%, respectively, were used. Seeds were subjected to deterioration by moisture, through artificially simulated rains. Pods of all cultivars were subjected to irrigation by constant sprinkling during 4 hours, and then dried in oven, set at 35 °C, for 37 hours; repeating twice such procedure. After these treatments seeds were subjected to tests and then compared to the control. Tests performed were: germination, accelerated aging and tetrazolium test; thereby quantifying the occurrence of damages by weathering damage. The activity of enzymes superoxide dismutase and guaiacol peroxidase was measured; and the lipid peroxidation was assessed. Soybean cultivars CD 208 and CD 215, with higher lignin content in the seed coat, were less susceptible to weathering damage. Seeds of cultivar CD 208 have also presented lower oxidative stress, when subjected to weathering damage stress

Crescimento in vitro de plântulas de batata em diferentes doses de cádmio In vitro growth of potato plantlets in different doses of cadmium

Devido, principalmente, às ações antropogênicas, tais como industrialização e uso de insumos na agricultura, os níveis de cádmio têm aumentado em muitos solos agrícolas. O presente trabalho objetivou caracterizar o efeito desse metal no crescimento in vitro de duas cultivares de batata, 'Asterix' e 'Macaca'. Segmentos nodais de plantas previamente estabelecidas in vitro foram submetidos a doses de cádmio de 0 (controle), 100, 200, 300, 400 e 500µM em meio de cultivo MS. Avaliou-se o número de raízes aos 15 dias após a inoculação (DAI) dos explantes, o comprimento das raízes e da parte aérea, o número de segmentos nodais e de folhas e a matéria fresca e seca das raízes e da parte aérea aos 22DAI. O cádmio afetou negativamente o crescimento das duas cultivares de batata, demonstrando que ambas são sensíveis a esse metal.<br>Levels of cadmium have been increasing in many agricultural soils mainly due to the anthropogenic actions, such as industrialization and use of inputs in the agriculture. The present research aimed at characterizing the effect of this metal on in vitro growth of two potato cultivars, 'Asterix' and 'Macaca'. Nodal segments of plants previously in vitro established were submitted to cadmium concentration of 0 (control), 100, 200, 300, 400 and 500µM in MS. Number of roots was evaluated at 15 days after inoculation (DAI) of the explants, and root and shoot length, number of nodal segments and leaves, and fresh and dry mass of roots and shoot were evaluated at 22DAI. Cadmium negatively affected the growth of the two potato cultivars, demonstrating that both are sensible to this metal