Phytodegradation Potential of Erythrina crista-galli L., Fabaceae, in Petroleum-Contaminated Soil

Abstract

This work aimed at investigating both the tolerance and the phytodegradation potential of Erythrina crista-galli L. in petroleum-contaminated soil. It consisted in analyzing E. crista-galli germination, surviving, growth, and development when cultivated at different contaminant concentrations and pollutant degradation rates. This specimen was selected because it presented a special behavior among others also exposed to petroleum in an accident that occurred in the Araucaria region (south of Brazil), resulting in a four-million-liter oil spill. The experiment was carried out in a greenhouse containing non-contaminated soil (NCS), vegetated contaminated soil (VCS), and non-vegetated contaminated soil (NVCS) at the following petroleum concentrations: 25 g kg(-1) (VCS-25), 50 g kg(-1) (VCS-50), and 75 g kg(-1) (VCS-75). After 60 days, the soil samples were analyzed by gas chromatography. Germination was more and more evident as higher petroleum concentrations were observed. The surviving rates of groups NCS, VCS-25, VCS-50, and VCS-75 were 64%, 70%, 61%, and 96%, respectively. The VCS group growth was reduced when compared to the control group (NCS). The individuals exposed to petroleum pollution presented differences in the anatomic structure of their roots when compared to the NCS group. It was observed that the petroleum degradation rate was higher for VCS group than for NVCS. E. crista-galli is potentially recommended for petroleum-contaminated soils because of its positive association in the presence of contamination.

Phytotoxicity of petroleum-contaminated soil and bioremediated soil on Allophylus edulis

“…Cell alterations recorded in the root epidermis of A. edulis in contaminated soil were also reported for other species subjected to contamination (Omosun et al 2008;Farias et al 2009). These alterations are probably caused by nutrient unavailability (Gill et al 1992) and by water stress (Omosun et al 2008;Farias et al 2009), caused by hydrocarbon contamination in the soil.…”

“…Consequently, these substances can alter seed germination (Adam & Duncan 2002;Ogbo 2009), growth (Adam & Duncan 1999;Merkl et al 2004) and plant biomass production (Malallah et al 1996;Sharifi et al 2007). However, in some species, germination is not affected by hydrocarbon-contaminated soils (Merkl et al 2004;Farias et al 2009). Petroleum contamination in the soil can even increase growth and biomass production of some plant species (Baker 1970;Merkl et al 2004Merkl et al , 2005, because the stress caused by this contaminant can stimulate the synthesis of growth-regulating substances (Baker 1970).…”

Efeito do solo contaminado com óleo diesel na estrutura da raiz e da folha de plântulas de Sebastiania commersoniana (Euphorbiaceae) e Schinus terebinthifolius (Anacardiaceae)

“…Esse fato evidencia que a resposta à contaminação do solo diferiu entre as espécies, e que S. terebinthifolius, parece mais resistente ao solo contaminado. Alterações, na epiderme da raiz em solo contaminado, também foram registradas para Erythrina crista-galli L., que apresentou células dispostas de maneira desorganizada (Farias et al 2009). No entanto, esses autores não relataram rompimento dessas células, o que foi evidenciado em S. commersoniana.…”

“…No entanto em S. commersoniana é mais evidente o aumento no número de células enquanto que em S. terebinthifolius os espaços intercelulares são mais proeminentes. O aumento nos espaços intercelulares do córtex de raízes em solo contaminado também foi registrado em Spartina alternifl ora Loisel., Sagittaria lancifolia L. e Erythrina crista-galli (Pezeshki et al 2000;Farias et al 2009). A formação de aerênquima pode reduzir o estresse hídrico (Levitt 1980) e o ambiente anóxico (Sift on 1945) provocados pela presença de hidrocarbonetos no solo (Baker 1970).…”

“…Embora a maioria dos trabalhos relate baixo desenvolvimento de plantas em solo contaminado (Racine 1994;Li et al 1997;Adam & Duncan 1999;Gill et al 1992;Dorn & Salanitro 2000;Chupakhina & Maslennikov 2004;Merkl et al 2005;Achuba 2006;White et al 2006;Omosun et al 2008;Farias et al 2009), também há registros de maior comprimento radicial (Baker 1970) e até de recuperação da biomassa (Merkl et al 2005). Alterações estruturais, como maior ramifi cação (Adam & Duncan 1999), alterações no formato das células da raiz (Farias et al 2009), redução das divisões celulares da raiz (Merkl et al 2004;Achuba 2006), alteração da estrutura dos pêlos radiculares (Alkio et al 2005), redução da área foliar, alteração na densidade estomática (Maranho et al 2006;Omosun et al 2008) e modifi cações no aspecto e espessura da cera epicuticular (Baker 1970;Omosun et al 2008) foram registradas em diferentes espécies em solo contaminado.…”