Inheritance Profile of Weathered Chlordane andP,P′-DDTs Accumulation bycucurbita pepohybrids

Abstract

Cucurbita pepo ssp pepo (zucchini) accumulates significant levels of persistent organic pollutants in its roots, followed by unexpectedly high contaminant translocation to the stems. Most other plant species, including the closely related C. pepo ssp ovifera (squash), do not have this ability. To investigate the mechanism of contaminant accumulation, two cultivars each of parental zucchini and squash, as well as previously created first filial (F1) hybrids and F1 backcrosses (BC) of those parental cultivars, were grown under field conditions in a soil contaminated with weathered chlordane (2.29 microg/g) and DDX residues (0.30 microg/g; sum of DDT, DDE, DDD). The parental zucchini had stem-to-soil bioconcentration factors (BCF, contaminant ratio of stem to soil) for chlordane and DDX of 6.23 and 3.10; these values were 2.2 and 3.7 times greater than the squash, respectively. Chlordane and DDX translocation factors, the ratio of contaminant content in the stems to that in the root, were 2.1 and 3.2 times greater for zucchini than for squash. The parental zucchini and squash also differed significantly in chlordane component ratios (relative amounts of trans-nonachlor [TN], cis-chlordane [CC], trans-chlordane [TC]) and enantiomer fractions for the chiral CC and TC. Hybridization of the parental squash and zucchini resulted in significant differences in contaminant uptake. For both the three separate component ratios (CR) and two sets of enantiomer fraction (EF) values, subspecies specific differences in the parental generation became statistically equivalent in the F1 hybrid zucchini and squash. When backcrossed (BC) with the original parental plants, the zucchini and squash F1 BC cultivars reverted to the statistically distinct CR and EF patterns. This pattern of trait segregation upon hybridization suggests either single gene or single locus control for persistent organic pollutant (POP) uptake ability by C. pepo ssp pepo.

Multiwalled Carbon Nanotubes and C60Fullerenes Differentially Impact the Accumulation of Weathered Pesticides in Four Agricultural Plants

“…A sandy loam (69.4% sand, 22.0% silt, 8.6% clay; 4.3% organic matter; pH 5.9 [water]; cation exchange capacity 18.6 cmol/kg), containing weathered chlordane and DDx pesticide residues resulting from historical application, was collected from the Connecticut Agricultural Experiment Station (CAES). , The soil was air-dried for 2 d and sieved to 2 mm for homogeneity and to remove nonsoil debris. Because of the well-known but unpredictable breakdown of p,p ′-DDT to p,p ′-DDE/DDD in the GC inlet, total DDx was calculated as the sum of p,p ′-DDT, p,p ′-DDD, and p,p ′-DDE.…”

Comparative fate of an organochlorine, chlordecone, and a related compound, chlordecone-5b-hydro, in soils and plants

“…The relative distribution of HCH isomers has been shown to vary between soils and plants but also between plant tissues (Calvelo Pereira et al, 2006). Likewise, the ratio of chlordane enantiomers was shown to change upon entry in the plant (cucurbits) and a differential translocation was observed between crops and plant tissues (Isleyen et al, 2013). The authors assumed that this selectivity is the result of the properties of the contaminants and of plant physiology and composition.…”

Concomitant uptake of antimicrobials and Salmonella in soil and into lettuce following wastewater irrigation

“…Cultivar specific differences in uptake have been documented for organic pollutants such as chlordane in zucchinis and squash (Isleyen et al, 2013), organophosphate and DEET in carrots (Eggen et al, 2013); as well as nitrates in cabbage (Tang et al, 2013).…”