Efeito do solo contaminado por óleo diesel na germinação e fisiologia de Hymenaea courbaril L e Jatropha curcas L

Abstract

The object of this study was to analyze the effect of soil contaminated by diesel oil in the germination and physiology of Hymenaea courbaril L. and Jatropha curcas L. The experiments were conducted in a greenhouse of the Plant Physiology Laboratory - UFRPE. For the assembly of the experiments were used seeds and plants propagated sexually. The germination experiment evaluated: germination percentage (%G), germination speed index (GSI) and mean time germination (MTG). The experimental design was a factorial (2x3), two species (H. courbaril and J. curcas) and 3 treatments, T30 (contaminated soil after 30 days), T60 (contaminated soil after 60 days) and T0 (without soil contamination), 3 replications. The second experiment used plants of H. courbaril and J. curcas and evaluated, gas exchange (photosynthesis - A; Transpiration - E; Stomatal Conductance - gs); water relations (Potential Hydride Leaf - w; Relative Water Content - RWC); photosynthetic pigments (chlorophyll a, b, total and carotenoids); index chlorophyll- SPAD; protoplasmic damage and organic solutes (carbohydrates, amino acids, protein and proline). The experimental design was in a factorial design (2x3x2), 2 species (H. courbaril and J. curcas); 3 treatments: T0 (100% of the maximum water holding capacity of the soil - without contamination); T1 (50% of maximum water holding capacity of the soil + addition of 23 mL of diesel per kg of soil) and T2 (50% of maximum water holding capacity of the soil + 46,2mL of diesel per kg of soil); and 2 times (3hours and 192hours after contamination), 5 repetitions. The %G, IVG and TMG H. courbaril and J. curcas in seed were affected, germination does not occur for any of the species in no of contamination treatments. For the seeds of T0 (H. courbaril and J. curcas), they presented %G 84.51% and 82.29%, germination speed index of 17.29 and 12.02 (seedling / day ) and mean germination time of 1.41 and 3.04 (day), respectively. For H. courbaril plants and J. curcas, they show differences 3h after application to stress to gas exchange (A, E and gs), with percentages of 127% and 169%; 96.24% and 190%; 401.5% and 651.87% for T1 and T2, respectively, when compared to T0. The w showed reductions after 3h in H. courbaril and J. curcas with average: -2.63 MPa and -2.75 MPa -2,3MPa; -1.35 MPa to -2.05 MPa and -2,53MPa T0, T1 and T2, respectively. After of 192h, both species recovered their water status and increased their w with average: -1,05MPa and -1,5MPa; -1.16 MPa and -0.65 MPa for the T1 and T2 treatments for H. courbaril and J. curcas, respectively. The solutes demonstrated that the species showed tolerance mechanisms after 3h and stomatal closure with stress prolonged. Photosynthetic pigments and chlorophyll index-SPAD showed an increase after 192h. Protoplasmic damage also showed increases, being more pronounced in J. curcas plants after 192h. Given the above, it is suggested to using plants instead of seeds in contaminated areas with diesel oil.