Heritability of Phytoremediation Potential for the Alfalfa CultivarRiley in Petroleum Contaminated Soil

Abstract

Petroleum contamination poses a significant threat to environmental ecosystems worldwide. Phytoremediation can be used to enhance degradation of petroleum contaminants in soil. However, selection of plants for phytoremediation has proven to be complicated. This research examines the heritability of the alfalfa cultivar Riley for phytoremediation based on parental total petroleum hydrocarbon (TPH) degradation after twelve months of growth. Traits other than degradation potential, such as root and shoot yield, height, and maturity, were examined for use as selection traits. Riley showed moderate to low heritability that suggests the possibility of breeding for phytoremediation efficiency. In addition, root and shoot yield were found to correlate to TPH degradation. Crosses in which the female parent was typically associated with low TPH dissipation yielded progeny that were high efficiency TPH degraders.

Influence of Rhizobium meliloti on phytoremediation of polycyclic aromatic hydrocarbons by alfalfa in an aged contaminated soil

“…The efficiency of phytoremediation relies on the establishment of active plants with sufficient biomass growth, active root proliferation and/or root activities that can support a flourishing microbial consortium assisting phytoremediation in the rhizosphere [3,40,41]. Legumes, including alfalfa, have been identified as strong candidates for remediation of contaminated sites [22,23,42,43]. In the present study planted soil did show significantly lower concentrations of PAHs suggests that alfalfa in this experiment played a role in the remediation of PAH-contaminated soil.…”

“…Rhizobial bacteria have been studied in relation to phytoremediation because of their potential to form symbiotic associations with leguminous plants [18][19][20]. Alfalfa (Medicago sativa L.), the most widely grown perennial legume in the world, is a deep-rooted perennial species that may have strong potential for the remediation of a number of organic contaminants [21][22][23][24]. Studies have therefore begun on the potential of the alfalfa-Rhizobium symbiosis to remediate soils contaminated with persistent organic pollutants such as polychlorinated biphenyls (PCBs) and petroleum hydrocarbon compounds (PHC) [21,25,26].…”

Plant root exudates impact the hydrocarbon degradation potential of a weathered-hydrocarbon contaminated soil

“…Comparable differences in exudation patterns may have contributed to the heritable differences in crude oil degradation facilitated by genotypic clones of alfalfa in another study (Schwab et al, 2006;van Elsas et al, 2003). Our results suggest that the patterns of exudation are the driving factors behind the degradation traits.…”

“…Differences in degradation potential are also observed between specific cultivars of a plant. Genotypic clones of Medicago sativa cv Riley (alfalfa) have been found to promote different amounts of crude oil degradation (Schwab et al, 2006;Wiltse et al, 1998). Some genotypes increased degradation while others decreased degradation relative to an un-planted control.…”

Influence of diesel and biodiesel fuel-contaminated soil on microorganisms, growth and development of plants

“…The plants can stimulate the microbiological activity of soils (Reilley et al 1996). The multiplication of microorganism in the root zone of the plants may be the result of the increased availability of nutrients produced by the plants, which also improves the oxygen conditions of the soil (Schwab et al 2006). In the conducted microbiological studies, in the rhizosphere area of the pea plants, stimulation of the development of heterotrophic microorganisms (over 30% increase), degrading diesel fuel (over 85% increase), and the content of biomass in the soil contaminated with pure diesel oil by over 20% in relation to the control and soil not covered with vegetation were noted.…”