Effect of Salicylic Acid on the Physiological Quality of Salt-Stressed Cucumis melo Seeds

Abstract

Aim: The aim of this study was to evaluate the physiological quality of seeds of two melon varieties (Cucumis melo) in response to saline stress and salicylic acid treatment. Study Design:  The experimental design was a completely randomized design with five different water salinities and five doses of salicylic acid, with four replicates of 50 seeds. Place and Duration of Study: The experiment was carried out in the Laboratory of Seed Analysis, located in the Center of Agricultural Sciences of the Federal University of Paraíba, Areia-PB, Brazil. Methodology: The experiment was conducted with two varieties of melon (Cantalupensis and Eldorado 300). Creole melon seeds (cucumber melon - Cantalupensis) were extracted from completely mature fruits produced in a farmland located in Santa Luzia, PB, Brazil. The Eldorado 300 seeds were purchased in the local market of Areia, PB, Brazil. A completely randomized experimental design was used with five water salinities (ECw = 0.0, 1.74, 6.0, 10.26 and 12.0 dS m-1) and five salicylic acid doses (SA = 0.0, 0.29, 1.0, 1.71 and 2.0 mM), with four replicates of 50 seeds. The following variables were evaluated: percentage of germination, first germination count, percentage of abnormal seedlings, germination speed index, mean germination time, seedlings dry mass and the root, shoot and seedling length. Results: Salicylic acid treatment was not effective in attenuating the harmful effects of saline stress on seed germination. Cantalupensis cultivar is more tolerant than the Eldorado 300 cultivar. Conclusion: Saline stress has a negative effect on the germination and vigor of melon seeds. Salicylic acid was not effective in attenuate the deleterious effects promoted by water salinity.