Leguminous trees have a potential for phytoremediation of oil-contaminated areas for its symbiotic association with nitrogen-fixing bacteria and arbuscular mycorrhizal fungi (AMF). This study selects leguminous tree associated with symbiotic microorganisms that have the potential to remediate petroleum-contaminated soil. Seven species of trees were tested: Acacia angustissima, Acacia auriculiformis, Acacia holosericea, Acacia mangium, Mimosa artemisiana, Mimosa caesalpiniifolia, and Samanea saman. They were inoculated with AMF mix and nitrogen-fixing bacteria mix and cultivated over five oil levels in soils, with five replicates. The decreasing of total petroleum hydrocarbons (TPH) values occurred especially with S. saman and its symbiotic microorganisms on highest oil soil contamination. Despite the large growth of A. angustissima and M. caesalpiniifolia on the highest level of oil, these species and its inoculated microorganisms did not reduce the soil TPH. Both plants were hydrocarbon tolerant but not able to remediate the polluted soil. In contrast were significative hydrocarbon decrease with M. artemisiana under high oil concentrations, but plant growth was severely affected. Results suggest that the ability of the plants to decrease the soil concentration of TPH is not directly related to its growth and adaptation to conditions of contamination, but the success of the association between plants and its symbionts that seem to play a critical role on remediation efficiency.

Silver nanoparticles synthesized using the leaf extract of Albizia saman (Jacq.) Merr. were tested for induction of cytogenetic abnormality in root tip cells of Drimia indica (Roxb.) Jessop (family Asperagaceae). The leaves are known to be rich in various phytochemicals like flavonoids, glycosides, saponins, steroids, tannins, and terpenoids, which may be responsible for bioreduction, biocapping, and stabilization of nanoparticles. The various instruments used for characterization include UV-VIS spectrophotometer, fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), X-Ray diffractometer (XRD), and high resolution transmission electron microscope (HR-TEM). The present study aims to evaluate the cytotoxic effect of biogenic silver nanoparticles on mitotic chromosomes by using root tip cells of D. indica. The root tips of D. indica was treated with suspensions of silver nanoparticles mixed in distilled water at different concentrations viz., 25, 50, 75, and 100% (w/v) for 6, 12, 18, and 24 h and then fixed in 1:3 ethanol: acetic acid following pre-treatment with 0.05% colchicine for cytological analysis. Silver nanoparticles induced a dose dependent decrease of mitotic index in root meristems. Furthermore, the treated meristem cells showed various types of chromosomal and mitotic aberrations such as anaphase bridge, sticky metaphase, lagging, or forward chromosome indicating genotoxic damage.