A physiological analysis of Genipa americana L.: A potential phytoremediator tree for chromium polluted watersheds

摘要: Abstract Chromium is a highly toxic heavy metal for microorganisms, animals and plants. Due to its widespread industrial use, it has become serious pollutant in diverse array of environments. Genipa americana L. (Rubiaceae) neotropical wood plant that shows adaptive capabilities adverse conditions, such as soil flooding. We conducted an experiment under greenhouse conditions order test the hypothesis G. can be used phytoremediator tree Cr3+-contaminated watersheds. In this way, approximately 2-month-old seedlings were subjected increased concentrations Cr3+ nutritive solution analyse effects on leaf gas exchange, growth, carbon allocation mineral composition above belowground components dry mass. The submitted seven increasing nutrient solution. At 34 days, exchange parameters maximal tested dose (30 mg L−1) remained below control; net values photosynthetic rate (A) stomatal conductance water vapor (gs) lowered 80 90%, respectively. There decreases 36% total area (LA) between 0 30 mg L−1 reductions roots, stems, leaves biomasses 29, 39, 30 31%, largest A gs ratios obtained controls. accumulated preferentially roots low levels transport aerial parts was detected. Notwithstanding, Cu Na with increment On other hand, Fe K contents presented negative proportional increase concentration Cr3+. little effect Mn, N P seedlings. Despite some stress symptoms (root-apex necrosis, chlorosis, gs, growth absorption elements), showed great amount uptake from solution, immobilizing storing high roots. Therefore, woody species presents potential phytoremediator, mainly rhizofilterer phytostabilizer