Germination and Seedling Growth of the Chilean Native Grass Polypogon Australis in Soil Polluted with Diesel Oil

The purpose of this study was to evaluate the ability of Polypogon australis, a Chilean native grass that colonizes copper polluted sites, to germinate and grow in soil contaminated with diesel oil. The effect of increasing proportions of diesel in soil (0.5%, 1%, 2%, and 5%) on the cumulative germination and growth of plants was measured. The relative seed germination (RSG), relative root growth (RRG), germination index (GI), and the effective concentration (EC 50 ) were calculated. The cumulative germination in soil polluted with 0%, 0.5%, 1%, and 2% of diesel oil in soil was 93.3%, 85.5%, 99%, and 78.5%, respectively, showing no significant differences between the treatments (p > 0.05). A proportion of 5% of diesel in the soil reduced the germination of P. australis by 50%, compared to the control. The growth of leaves and roots of the plants germinated in 5% of diesel was reduced by 30% compared to the control, with a 34% survival rate observed on day 40. The calculated EC 50 of diesel for P. australis was 4.5%. P. australis germinated and grew on all diesel concentration used in the experiments. The species was classified as a tolerant to diesel oil. © 2019, © 2019 Taylor & Francis Group, LLC.