Germination Performance of Different Sorghum Cultivars under Saline Conditions

Sorghum bicolor (L.) Moench is among the most-produced cereal in the world. Although this species grows well in different environments, the accumulation of salts in the soil generality limits its development. Hence, this study aimed to evaluate the influence of salinity on the germinative aspects of four sorghum cultivars. The experiment was carried out at the Laboratories of Ecophysiology of Plant Production and Seed Analysis, both at the Federal University of Ceará (UFC), located in Fortaleza, Ceará State, Brazil. The experimental design used was completely randomized (CRD), in a 4 x 5 factorial arrangement, with four sorghum cultivars (BRS-373, BRS-380, BRS-658, and BRS-716) and five NaCl concentrations (0, 50, 100, 150 and 200 mM), with four replications. The variables investigated were final germination percentage (FGP), first count germination (FCG), mean germination time (MGT), germination speed index (GSI) and sodium and potassium contents (radicle and aerial part). The findings demonstrated that the salinity levels interfered negatively in the germination performance of all cultivars, showing an expressive reduction, mainly in the highest concentration of NaCl. The lowest germination indices were observed for BRS-373 cultivar, which, although it has shown less sodium accumulation in the root, was enough to cause metabolism delays. On the other hand, the BRS-716 cultivar exhibited the greatest potential for salinity tolerance in the early stages of development, higher germination indices and lower sodium accumulation when compared to potassium in the aerial part.