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Parental environments can influence offspring traits. However, the magnitude of the impact of parental environments on offspring molecular phenotypes is poorly understood. Here, we test the direct effects and intergenerational effects of jasmonic acid (JA) treatment, which is involved in herbivory-induced defense signaling, on transcriptomes and metabolomes in apomictic common dandelion (Taraxacum officinale). In a full factorial crossed design with parental and offspring JA and control treatments, we performed leaf RNA-seq gene expression analysis, LC-MS metabolomics and total phenolics assays in offspring plants. Expression analysis, leveraged by a de novo assembled transcriptome, revealed an induced response to JA exposure that is consistent with known JA effects. The intergenerational effect of treatment was considerable: 307 of 858 detected JA-responsive transcripts were affected by parental JA treatment. In terms of the numbers of metabolites affected, the magnitude of the chemical response to parental JA exposure was c. 10% of the direct JA treatment response. Transcriptome and metabolome analyses both identified the phosphatidylinositol signaling pathway as a target of intergenerational JA effects. Our results highlight that parental environments can have substantial effects in offspring generations. Transcriptome and metabolome assays provide a basis for zooming in on the potential mechanisms of inherited JA effects.

Consumption of common dandelion (Taraxacum officinale agg.) can pose a risk when foraged in agroecosystems like vineyards where pesticides are frequently used. The aims of our study are to evaluate whether dandelion foraged in vineyards with different management practices (integrated pest management, organic, and biodynamic) in spring is suitable for consumption and to assess whether the contents of selected pesticide residues (PR) in integrated vineyards in dandelion vary throughout the seasons. Young dandelion leaves were sampled in spring, summer, and autumn in integrated vineyards, while in spring also in organic and biodynamic vineyards. The selected PR was analyzed using GC-MS/MS and LC-MS/MS, using extraction with acetonitrile. The method was validated on a dandelion matrix according to international guideline SANTE 11312/2021. Despite the use of many pesticides in integrated vineyards, only tebuconazole was detected in spring in one sample (0.005 mg/kg), while no PR was detected in dandelion from organic and biodynamic vineyards. However, at summer sampling seven different PR were detected, of which the kresoxim-methyl maximum residue limit was exceeded in five samples (0.012–0.029 mg/kg), while in autumn no PR was detected. Based on this study, it seems that dandelion leaves foraged in vineyards in spring could be unproblematic for consumption.

Phenotypic plasticity and broad ecological tolerance are hypothesized as important traits in the range expansion of asexual species, because individual asexual lineages have to face spatial and temporal environmental variation with limited opportunity for genetic adaptation. The hypothesis that asexual lineages are general‐purpose genotypes (GPG) has been previously tested, with mixed results, in species that have both sexual and asexual variants. Such comparisons can be confounded with intraspecific ploidy level differences that are often observed between the two reproductive types. Avoiding the confounding effects of ploidy differences, we test whether northward range expansion selects for a GPG strategy in asexual lineages of the common dandelion (Taraxacum officinale), a species that shows geographic parthenogenesis. We compared the biomass of asexual lineages that were collected along a geographic transect from close to the asexuals’ area of origin (central Europe, where asexuals descend from sexual ancestors in mixed populations) towards their northern distribution edge (Northern Europe, where only asexual lineages occur) in three different experimental environments: optimal, drought and shaded conditions. The geometric mean performance across test environments did not differ significantly between plants from different regions along the transect. However, southern lineages typically showed larger differences in biomass between different test environments, mainly caused by a relatively high performance in the optimal environment. Northern and mid‐latitude lineages showed more even performance across the different environments. Synthesis. Our results suggest that phenotypic plasticity is important in the asexual range expansion of Taraxacum officinale and that range shifting in this species is accompanied by a change in phenotypic plasticity strategy from lineages with high ability to increase biomass in optimal growing conditions (master‐of‐some strategy) to lineages that maintain more constant performance in different environments (GPG or jack‐of‐all‐trades strategy) from core to range edge.

Apomixis is the ability of plants to produce asexual seeds, which are clones of the mother plant. The phenomenon of apomixis is tightly linked to ploidy, where diploids lack apomixis and reproduce sexually, while higher ploidy levels can exhibit apomixis. Taraxacum F.H.Wigg. species (dandelions) commonly exhibit apomixis; however, only limited studies have evaluated genome size variation of the iconic weedy dandelion, Taraxacum officinale F.H.Wigg. (common dandelion), particularly in North America. To evaluate the ploidy and reproductive biology of common dandelion, we created a global collection, with an emphasis on North America and determined genome size by evaluating seeds with flow cytometry. A total of 635 accessions were screened, and with the exception of two accessions from Germany and Austria, all were found to exclusively contain polyploid seed. The mode of reproduction of a sample of 96 of these accessions was observed by conducting emasculations. Our results indicate that the diploid, sexual cytotype of common dandelion may be absent in North America, while diploids were found in previously described areas of Central Europe. This suggests that the clonal lineages of common dandelion in North America may largely be derivative from apomictic plants introduced from abroad. Furthermore, if all North American common dandelion is apomictic, it may be unreceptive to pollen, which may isolate it from other dandelion species and inform the potential for gene flow.

1. Common dandelion Taraxacum officinale is the most abundant and frequent weed within turfgrass in temperate climates. With increasing legislation banning herbicide & non-chemical means of control are needed replace phenoxy herbicides. The weediness of T. officinale is mainly the result of high seed production, dispersal and germination potential. A successful long-term weed control strategy should suppress established plants, exert negative effects on seed production and prevent seedling establishment. 2. The potential of Sclerotinia minor to cause T. officinale seed mortality and reduce seedling emergence without impact on turfgrass species was evaluated in greenhouse and field experiments. 3. A pre-emergence application of S. minor at the time of seeding and a post-emergence application at 10 days after seeding significantly reduced T. officinale emergence to 17% and 2%, respectively, compared with 70-80% germination in the untreated control. There were no adverse effects of direct S. minor contact on turfgrass seed germination, seedling emergence or seedling establishment. 4. Grass overseeding alone did not improve grass quality or reduce T. officinale population densities in a low-maintained lawn environment. When S. minor was combined with grass overseeding, at application or 10 days after application, a 70-80% reduction of the T. officinale population occurred in the first year, increasing to 95% in the following year in the absence of further treatments. Turfgrass appearance and quality significantly and continuously improved up to 80%, compared with 10-20% in the control plots. Densities of other weeds, white clover Trifolium repens and field bindweed Convolvulus arvensis, were also significantly reduced when S. minor was applied with grass overseeding compared with the bioherbicide alone. 5. Synthesis and applications. We have demonstrated that S. minor reduces seed numbers, seedlings and establishment of T. officinale and, when combined with grass overseeding, the grass sward flourishes and weed emergence and colonization are significantly reduced. Other broadleaf weeds are susceptible to S. minor and thus this bioherbicide could have utility in no-till maize, cereal grain and grass seed production systems, where producers are searching for non-chemical weed control.

Common dandelion has developed into a troublesome agronomic weed for no-tillage corn producers. A postemergence herbicide application is often required to reduce common dandelion competition. Field experiments were conducted in 2002 and 2003 to evaluate 22 postemergence herbicide treatments for efficacy on established populations of common dandelion in no-tillage corn. All herbicides were applied to five- to six-collar corn at registered rates with typical adjuvants. At 28 d after treatment (DAT) the most effective treatments included glufosinate and mesotrione providing at least 76% control of common dandelion. All other herbicide treatments provided less than 40% common dandelion control 28 DAT. Common dandelion control was evaluated 56 DAT when regrowth of treated plants was observed for some herbicide treatments. AT 56 DAT, dicamba + diflufenzopyr was the most effective treatment, providing 83% control of common dandelion. In 2002, all herbicide treatments, with the exception of flumiclorac, resulted in corn yields greater than the nontreated. Nomenclature: Dicamba, diflufenzopyr, flumiclorac, glufosinate, mesotrione, common dandelion, Taraxacum officinale Weber TAROF, corn, Zea mays L

Given the important medicinal and nutritional value of wild edible greens, the last few years there is an increasing interest for their domestication and commercial exploitation. However, information concerning their adaptation to environmental conditions and their response to modern agricultural systems are scarce. In the present study, the effect of nutrient solution pH (4.0, 5.5 and 7.0) on the growth, chemical composition and inorganic nutrition of Taraxacum officinale and Reichardia picroides plants grown indoors in a floating hydroponic system was evaluated. Both species performed better at pH 5.5 and were slightly affected by pH 7.0, whereas pH 4.0 was not prohibitive for growth for both species, although R. picroides was less tolerant than T. officinale at low pH. Moreover, pH 4.0 did not severely affect nutrients uptake and transport within the plant tissues, suggesting that R. picroides susceptibility to low pH should not be attributed to nutrients imbalance. Nevertheless, low pH positively enhanced the content in total soluble solids, total phenolics, chlorophylls (a, b and total) and carotenoids, and decreased nitrates in both species. In conclusion, the studied species could be successfully grown in soilless systems with nutrient solutions of varied pH. Moreover, low pH levels (pH = 4.0) seemed to be beneficial to nutritional and dietary value in both species highlighting the potential of commercial cultivation under adverse conditions, especially in sustainable farming systems.

The spatial variation (within a 100 × 100 m plot) in the pollution of forest litter with heavy metals (Cu, Cd, Pb, and Zn), its acidity, and phytotoxicity (measured by the results of the root test using seedlings from a genetically homogeneous sample of common dandelion (Taraxacum officinale s.l.) have been estimated. Forest litter has been sampled in three zones differing in the toxic impact of long-term polymetal pollution by emissions from a copper-smelting plant emissions in the Middle Urals. The phytotoxicity variation is maximum in a moderately polluted plot, where both very high and very low pollution levels were observed, which determines a substantially nonlinear dose-effect relationship. The litter phytotoxicity is mainly accounted for by exchangeable forms of metals. Biological testing of samples from the most polluted plot has demonstrated marked antagonism between heavy metals and acidity.[PUBLICATION ABSTRACT]

Soil salinization is one of the major environmental factors responsible for limited crop production throughout the world. Therefore, there is urgent need to find tolerant/resistant species to exploit in commercial cultivation systems. In this context, the valorization of wild edible greens for human consumption and/or medicinal purposes is gaining more and more interest. The aim of the present work was to study the effect of salinity, e.g., electrical conductivity: 2 mS cm−1 (nutrient solution EC), 6 mS cm−1 and 10 mS cm−1 on plant growth and chemical composition of Reichardia picroides and Taraxacum officinale plants grown in a floating hydroponic system. The results showed that R. picroides is a moderately salt-tolerant species, as the majority of plant growth parameters determined were not negatively affected under the treatment of 6 mS cm−1. On the other hand, the growth parameters of T. officinale plants were severely affected under the same conditions. Moreover, high salinity levels (EC at 10 mS cm−1) impaired the growth of both species. The content of leaves in chlorophylls (a, b and total), carotenoids+xanthophylls and total soluble solids was not significantly affected by the tested EC levels in both species, whereas the titratable acidity increased under the treatment of 10 mS cm−1. Moreover, R. picroides exhibited a more effective adaptation mechanism against saline conditions than T. officinale, as evidenced by the higher accumulation of osmolytes such as proline and the higher shoot K content, probably through a more efficient K/Na selectivity. In conclusion, both species were severely affected by high salinity; however, R. picroides showed promising results regarding its commercial cultivation under moderate salinity levels, especially in regions where resources of high-quality irrigation water are limited.

The aim of the current study was to test the effect of a diet supplemented with dandelion’s ( ) extract on the productive traits and blood parameters in common carp ( L.) cultivated in an recirculation aquaculture system. The carps were cultivated at a stocking density of 7.2 kg/m in recirculation aquaculture system. The fish were split into the following two experimental groups: DF (the fish were fed with feed supplemented with dandelion’s extract) and CF (the fish were fed with feed without supplementation). Common carp fed with a diet added with dandelion’s extract at a quantity of 0.8% from daily feed ratio, did not affect the hydrochemical parameters (pH, dissolved oxygen, and electrical conductivity). The carps fed with feed supplemented with dandelion’s extract did not show better productive traits compared with these found for carp from the control variant. The carp from experimental groups had a higher survival rate, final weight, average individual weight gain and specific growth rate (SGR), respectively with 13.2%, 3.94%, 31.5% and 31.3%, compared with the average values of these parameters measured in individuals fed with the control feed, but the differences were not statistically significant (P≥0.05). Supplementation of feed with dandelion’s extract significantly decreased the plasma cholesterol (4.76%) and triglyceride (61.2%) content, promoting hypolipidemic status in fish (P≤0.05).