Phytotoxicity of chlorpyrifos to white mustard (Sinapis alba L.) and maize (Zea mays L.): Potential indicators of insecticide presence in water

Abstract

SuMMARYChlorpyrifos is a hazardous insecticide and important pollutant of the environment. The EU Directive 2008/105/EC lists it as one of the priority water pollutants. Its presence is mainly detected by chemical methods but, since biological tests have gained in importance in the last few years, this study aimed to assess the potentials of white mustard (Sinapis alba L.) and maize (Zea mays L.) as indicators of water pollution. The phytotoxic effects of chlorpyrifos (rates 0.05-10µg a.i./l) were assessed based on physiological (germination energy and germination) and morphological traits (root and shoot length, fresh and dry weights) of the tested species. A slightly modified filter paper method was used and the results were processed by Duncan`s multiple range test and Probit analysis (EC 50 ). According to the Directive, the maximal allowable concentration (MAC) of chlorpyrifos in water is 0.1µg a.i./l. When applied at the MAC value, chlorpyrifos inhibited germination energy and germination (11.25%) of white mustard, as compared to the control (91.5; 93.5%), and its hypocotyls and epicotyls failed to form. At the rates 50% below the MAC, germination energy and germination (87.75; 88.25%) were significanty inhibited, as well as root and shoot growth of seedlings. Chlorpyrofos did not affect the germination energy and germination of maize, while all morphological traits were significantly reduced by chlorpyrifos at the MAC rate. The EC 50 of chlorpyrifos was 0.09µg a.i./l for germination of white mustard and 3.21µg a.i./l for maize.

The Toxicity of Two Types of Sewage Sludge From Wastewater Treatment Plant for Plants in Czech Republic

“…The test species, white mustard (Sinapis alba L.) expressed different sensitivity levels to contamination. This is consistent with the findings of Gvozdenac et al [2013] where tolerance levels of crops are species dependent and vary under different stress intensities (concentrations and types of pollutants) and growth stages (germination, emergence, vegetative growth, etc.). In the present study, two types of sewage sludge: dewatered and anaerobically stabilized sludge with dry matter content of about 24%, and dewatered sludge "Palikal" with dry matter content of about 92% caused phytotoxic effects on the tested plant species, manifesting as root and shoot growth reduction or total inhibition.…”

“…Biological assays have been used for several decades in risk assessment and detection of water/sludge contamination have mainly involved aquatic invertebrates (chironomid larvae, mosquitoes, dragon flies, prawns, shells and hydras), aquatic vertebrates such as fish and algae, and aquatic plants such as Lemna minor L. Based on these facts, it is obvious that the use of plants as indicators of contamination has been generally underestimated and rarely used in toxicological studies, compared to animal organisms [Moor and Kroege, 2010]. However, the significance of research that involves phytoindicators should not be neglected because such data show the bioavailability of contaminants and enable risk assessment and creation of protocols for remediation of contaminated sites [Gvozdenac et al, 2013].…”

Chlorpyrifos: pollution and remediation

“…Chlorpyrifos was found to have inhibitory effect on germination in Pinus halepensis seeds and seedlings (Olofinboba and Kozlowski 1982), annual grass and annual forb (Gange et al 1992), ryegrass (Lolium multiflorum) (Korade and Fulekar 2009), different vegetables (Zhang et al 2013), Cenchrus setigerus and Pennisetum pedicellatum (Dubey and Fulekar 2011), white mustard (Sinapis alba L.), maize (Zea mays L.) (Gvozdenac et al 2013), and soybean (Glycine max) (Bassey et al 2015). The intensity of toxicity on seed germination energy, seed germination, survival, and subsequent growth increases with chlorpyrifos concentration (Dubey and Fulekar 2011;Gvozdenac et al 2013). It has also been reported to exert detrimental effect on the root biomass, root appearance and disappearance, and root density (Dawson et al 2003;Singh et al 2003a).…”

Study of the Effects of High Levels of Nutrients on Seed Germination and Root Elongation

“…A standard filter paper method [20] was used for the test. White mustard seeds (30 per replication, with three replications) were placed in Petri dishes (Ø15 cm) on filter paper moistened with 20 ml of solution [9]. For water toxicology 3 ml of original water was used for each sample.…”

“…Wierzbicka and Obidzinska [8] demonstrated that seed coats were the main barrier to contaminants, and prevent contamination of embryos until the seed coat is torn apart by the germinating embryonic root. Germination of seeds may depend on such parameters as the seed structure and seed coats [9]. Plant species are recommended by the U.S. Environmental Protection Agency (EPA) and the Organization for Economic Cooperation and Development (OECD).…”