Enhancement of Seed Germination and Uniformity in Triploid Watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai)

One of the main factors restricting production of triploid seedless watermelon is poor germination due to weak embryos, thick seed coats, and larger air spaces. This study was carried out to investigate the priming effects of different concentrations of chemicals, including hydrogen peroxide (H2O2), fusicoccin, and gibberellic acid (GA) on germination and seedling uniformity of triploid watermelon (Citrullus lanatus). Three commercial triploid cultivars, Seedless Plus, Sinus, and Sizero, were pretreated with water and different levels of H2O2 (2 and 4%), fusicoccin (FC: 1, 5, and 10 mu M), and GA (1, 5, and 10 mu M). The present findings helped to find optimal priming conditions for improving germination of triploid watermelon. Treatment with 5 mu M GA and hydropriming helped to break seed dormancy, enhancing the final germination percentages in all triploid cultivars and increasing the germination index in Sizero. These seed-priming treatments could be used on large scale for industrial applications. Moreover, hydropriming provides a simple, effective, and costless method to improve seed germination and seedling vigor of Sinus and Sizero varieties.