Variability of alkaloid content in Papaver somniferum L.

A total of 300 accessions of opium poppy (Papaver somniferum L., Papaveraceae) of the IPK genebank collection from nearly all over the world were cultivated under field conditions in Gatersleben for morphological and phytochemical characterisation. Altogether 35 morphological and agronomic characters were collected for all accessions. Determination of chromosome numbers with flow cytometry showed that the accessions of subspecies setigerum are tetraploid whereas all accessions of the other subspecies are diploid. Composition and content of the five main alkaloids (morphine, codeine, thebaine, papaverine and noscapine) were analysed by high performance liquid chromatography (HPLC). Total alkaloid content varied between 683.32 and 25,034.84 μg/g dry matter (first year) and 1,799.49 and 25,338.55 μg/g dry matter in the second year of cultivation. There is a highly significant correlation between total content of alkaloids and morphine in both years (r=0.926/P=0.000; r=0.918/P=0.000). In contrast, the other four main alkaloids show less or no correlation with each other or the total alkaloid content. This analysis demonstrated that the amount and composition of the main alkaloids are highly variable. Additionally, there is no important correlation between morphological characters and alkaloid content. So it is not possible to use these characters as a prediction tool of alkaloid content during breeding process

Residual ground-water levels of the neonicotinoid thiacloprid perturb chemosensing of Caenorhabditis elegans

© 2017, The Author(s). This study investigated the neurological effects of residual ground-water levels of thiaclopridon the non-target organism Caenorhabditis elegans. Nematodes treated with thiacloprid showed a dose-dependent and significantly increased twitch response at concentrations above 50 ng mL−1 that disabled their forward locomotion in liquid culture. In comparison with untreated controls, 10 ng mL−1 thiacloprid perturbed the chemosensory ability of C. elegans such that the nematodes no longer demonstrated positive chemotaxis towards a NaCl chemo-attractant, reducing their chemotaxis index from +0.48 to near to zero. Nematodes also exhibited a locomotion characteristic of those devoid of chemo-attraction, making significantly more pirouetting turns of ≥90° than the untreated controls. Compared to the untreated controls, expression of the endocytosis-associated gene, Rab-10, was also increased in C. elegans that had developed to adulthood in the presence of 10 ng mL−1 thiacloprid, suggesting their active engagement in increased recycling of affected cellular components, such as their nAChRs. Thus, even residual, low levels of this less potent neonicotinoid that may be found in field ground-water had measurable effects on a beneficial soil organism which may have environmental and ecological implications that are currently poorly understood

Assessing the toxicity of thiamethoxam, in natural LUFA 2.2 soil, through three generations of Folsomia candida

In the field, long-term exposure is a rule rather than an exception. As a consequence, the relatively short-term standard toxicity tests may not be adequate for assessing long-term effects of pesticide exposure. This study determined the toxicity of the neonicotinoid thiamethoxam, both pure and in the formulation Actara® (25% active substance), to the springtail Folsomia candida, over three generations (P, F1 and F2). For the parental generation (P), the toxicity of pure thiamethoxam and Actara® did not differ significantly, with LC50s and EC50s of 0.32–0.35 and 0.23–0.25 mg a.s./kg dry soil, respectively. For the F1 and F2 generations, LC50s were >0.37 mg a.s./kg dry soil for both compounds. Actara was more toxic towards reproduction in the F1 generation (EC50 0.16 mg a.s./kg dry soil) than pure thiamethoxam (EC50 0.23 mg a.s./kg dry soil). For generation F2, there was no significant difference in the toxicity of the compounds towards reproduction, with EC50s of >0.37 and 0.30 mg a.s./kg dry soil for Actara® and pure thiamethoxam respectively. These results suggest a slight decrease in the toxicity of the compounds throughout the generations tested. The similarity in the toxicity of pure and formulated thiamethoxam indicates that the ingredients in the formulation Actara® do not enhance toxicity