RIBEIRO, V. C. S.; http://lattes.cnpq.br/9979666214146886; RIBEIRO, Vitória Cristina dos Santos.
Résumé:
Dragon fruit cultivation has been gaining prominence in several states in the semi-arid
region of Northeast Brazil, where some abiotic stresses are present and tend to limit
the productivity of many crops. The use of exogenous substances has been used to
mitigate abiotic stresses in plants. The present proposal aimed to evaluate the
influence of conditioning factors on the physiological performance of dragon fruit seeds
subjected to saline stress. The experiment was conducted in a completely randomized
design in a 5 x 6 factorial scheme, corresponding to five pre-germination treatments
(distilled water, gibberellic acid, salicylic acid, Thiamethoxam and Quicelum®) and six
saline concentrations (0; 1.0; 2. 0; 3.0; 4.0 and 5.0 dS.m-1) using four replications of
50 seeds per treatment. Physiological evaluations were carried out: percentage of
germination, germination speed index, length of aerial part and main root of seedlings
and total dry mass and biochemistry of total soluble sugar content. Analysis of variance
was carried out using the F test with 5% significance with means of the qualitative
variable compared using the Tukey test (p≤0.05), while the means of the quantitative
variable were subjected to polynomial regression analysis. The use of conditioning
agents, as well as salinity, did not influence the germination of the dragon fruit, the
dragon fruit is resistant to salinity. Salicylic acid, Quicelum® and Thiamethoxam
stimulated vigor, favoring rapid germination of dragon fruit seeds in salinity of up to 3
dS.m-1. Gibberellic acid, salicylic acid and Thiamethoxam guarantee good phytomass
formation at saline levels of up to 2.5 dS.m-1. Gibberellic acid, salicylic acid,
Quicelum® and Thiamethoxam improve the physiological performance of dragon fruit
seeds under saline stress conditions.