Evaluation of phytoremediation capability of French marigold (<i>Tagetes patula</i>) and African marigold (<i>Tagetes erecta</i>) under heavy metals contaminated soils
Creators: name: Biswal, Biswojit
name: Singh, Satish Kumar
name: Patra, Abhik
name: Mohapatra, Kiran Kumar
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biochemistry
subject: Molecular Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: 20199 Astronomical and Space Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: 69999 Biological Sciences not elsewhere classified

description: The pot experiment was conducted to explore the phytoremediation potential of two different marigold species grown in heavy metals contaminated red, black, alluvial, recent river clay, sewage irrigated, sewage sludge, and garden soil. Different soil types were treated uniformly with lead (20 mg Pb kg<sup>−1</sup> soil), cadmium (5 mg Cd kg<sup>−1</sup> soil), chromium (30 mg Cr kg<sup>−1</sup> soil) and nickel (10 mg Ni kg<sup>−1</sup> soil). Completely randomized design (CRD) was used with three replications. African marigold (<i>Tagetes erecta</i>) recorded ∼89.4% more dry matter yield over French marigold (<i>Tagetes patula</i>) when grown under metals treated soils. Both the marigold species were highly effective for removing Cd and Ni from contaminated soils (TF &gt;1) however, Ni (TF ∼14.9) was more efficiently accumulated by <i>T. patula</i> and Cd (TF ∼12.1) by <i>T. erecta</i>. Higher biomass yield in <i>T. erecta</i> resulted higher accumulation of heavy metals (except Cr) compared to <i>T. patula</i>. Assessment of contamination factor (CF) and geo-accumulation index (I<sub>geo</sub>) of heavy metals indicates that post-harvest soils had moderate to high degree of contamination by different metals, Cr being the highest. It may be concluded that <i>T. erecta</i> was more efficient in extracting heavy metals from different heavy metals contaminated soils. <b>Novelty statement</b> Contamination of land with heavy metals poses severe environmental threats. Physical and chemical remediation techniques are generally used for remediating metals contaminated sites. These methods are cost-intensive and therefore, commercially non-viable, besides being disruptive in nature and causing deterioration of soil. Alternatively, bio-remediation techniques are cost-effective and environment friendly. Among the various phytoremediation techniques, hyperaccumulator plants are most commonly used for the remediation of the contaminated sites. It has been found that different species of the same plant (marigold) differ in their ability to accumulate metals under various contaminated soils having different properties. Thus, this experiment provided an unique opportunity to investigate the effect of various soil properties on metal accumulation efficacy of marigold under metal-spiked soils. Marigold plants can grow rapidly by developing a robust root system which helps them to survive under contaminated soil environment. Thus, marigold being ornamental plant could be used to decontaminate polluted sites while providing ornamental value and may serve as a source of commercially valuable products extracting metals from biomass by way of incineration. However, meager information is available about the usage of various marigold species for phytoremediation of heavy metals under different metal-polluted soils. In the current experiment, we intend to evaluate the potential use of two different marigold species (<i>Tagetes patula</i> and <i>Tagetes erecta</i>) in remediating heavy metals under nine soils of different nature spiked with metals and assessing heavy metals pollution load indexes in these polluted soils.