Reciprocal interactions between aphids and arbuscular mycorrhizal fungi across plant generations

The conditions experienced by one plant generation can influence the growth of the offspring generation. These maternal effects can reduce performance of foliar-feeding insects, through accumulation of plant defences. Arbuscular mycorrhizal fungi (AMF) inhabit the roots of plants and are known to influence the performance of foliar-feeding insects. However, all published studies of the interactions between insects and AMF have taken place within one plant generation, but none across generations. Thus, in the present study, Senecio vulgaris plants were grown with or without aphids and AMF (termed ‘induction events’), and seeds from each treatment were used to grow plants experiencing that same treatment over four successive generations, all grown in identical environmental conditions. Naïve aphids were reared on Senecio plants whose parents had experienced 0, 1, 2 or 3 induction events. We found strong negative maternal effects of herbivory on aphid growth, which were not mitigated by the mycorrhiza. However, teneral weight and growth rate showed a gradual recovery; aphids reared on plants whose previous three generations suffered attack were similar in size to those at the beginning of the study. Herbivory had positive or negative effects on the mycorrhiza, dependent upon the number of previous generations suffering attack or having mycorrhizal associations. We conclude that the outcome of many insect plant fungal experiments is likely to have been influenced by and need to account for maternal effects of the parental plant’s growth conditions.

Morphological and genetic diversity of Senecio vulgaris L. (Asteraceae) in Iran

Senecio vulgaris L., an annual herb belonging to the Asteraceae, is widely distributed in different regions of the world. There is no information on the intraspecific variations of the morphological and molecular features of this species. In the present investigation, we studied the morphological and genetic diversity of 81 accessions of S. vulgaris collected from 10 geographical populations. Eleven inter simple sequence repeat (ISSR) primers were used for the examination of genetic variations among the populations. Analysis of molecular variance (AMOVA) and GST analyses revealed significant differences among the investigated populations. A significant correlation between genetic distance and geographical distance was revealed by the Mantel test. However, reticulation analysis indicated the occurrence of gene flow among most of the populations studied. Principal component analysis (PCA) plot showed that the number of capitula, length of the cauline leaf and plant height were the most variable morphological characters. Principal coordinates analysis (PCoA) plot revealed two groups of populations, according to molecular and morphological data. The results suggested the existence of possible intraspecific taxonomic ranks within this species.

Identification and Simultaneous Determination of the Main Toxical Pyrrolizidine Alkaloids in a Compound Prescription of Traditional Chinese Medicine: Qianbai Biyan Tablet

Qianbai biyan tablet (QT) is a compound prescription of traditional Chinese medicine which is used to treat nasal congestion, rhinitis, and nasosinusitis, with Senecio scandens as its main plant material. Several pyrrolizidine alkaloids (PAs) were reported in Senecio scandens and others of Senecio species. Although Senecio scandens is assigned as the legal plant material of QT, whether replaced use of it by other Senecio plants can bring toxicity is unknown because of the lack of quantitative data about toxic PAs between different Senecio species. In the present study, adonifoline, senkirkine, and another PA presumed as emiline have been identified in QT; however, there was no senecionine detected in all tablets. PA contents in QTs varied in different companies and different batches. Adonifoline existed only in Senecio scandens, and senecionine was detected in all eight Senecio plants investigated in the present study. Data showed that replaced use of Senecio scandens with a low level of senecionine by other Senecio plants such as Senecio vulgaris containing a high level of senecionine is advertised to be forbidden. Data of the present study may be used as a reference to make new drug quality regularity and recommendation guideline for the safety of QT.

Effects of latitudinal variation on field and common garden comparisons between native and introduced groundsel (Senecio vulgaris) populations

Aims Field and common garden comparisons are commonly performed to test the rapid evolution of increased vigor in introduced plant populations. Latitudinal clines in phenotypic traits can obscure such evolutionary inferences, particularly when native or introduced populations are distributed across large geographic ranges. We tested whether the latitudinal clines influence comparisons between introduced and native populations of Senecio vulgaris. Methods Senecio vulgaris is native to Europe but has been introduced in northeastern and southwestern China. To evaluate the performance in terms of growth and reproduction between native European populations and introduced Chinese populations, we compared plant height, number of branches and number of capitula in field populations in native and introduced ranges and in a common garden in Switzerland. Important Findings The introduced Chinese populations performed better than the native European populations in the field in terms of plant height and number of capitula, which was consistent with the prediction of the evolution of the increased competitive ability (EICA) hypothesis. The Chinese populations produced more capitula than the European populations when the latitudinal cline was considered in the common garden comparison. When we compared the traits of the northeastern Chinese, southwestern Chinese and European populations in both the field and common garden, the northeastern Chinese populations, at latitudes similar to those of the European populations, exhibited greater plant size and more capitula than the European populations in both the field and common garden. However, the southwestern Chinese populations, at latitudes much lower than those of the European populations, did not perform better than the native populations in terms of reproduction. In conclusion, our results suggest that latitudinal clines in phenotypic traits should be considered in field and common garden comparisons when introduced populations are geographically structured.

Phytotesting of heavy metal contamination of Donbass soils

The article presents the results of phytotesting of soil solutions with high concentrations of heavy metal ions. The sensitivity of Donbass species plant to soil pollution was established by specific transformations in the structures of the embryonic root Achillea nobilis L., Artemisia vulgaris L., Centaurea diffusa Lam., Galinsoga parviflora Cav., Senecio vulgaris L., Tripleurospermum inodorum (L.) Sch. Bip. Model experiments on plant germination were carried out in laboratory conditions with fixed concentrations of individual metals and with joint pollution, as well as when testing soil samples taken in the zones of influence of industrial facilities of Don-bass.

STATUS OF HERBICIDE RESISTANCE IN WEEDS AND THE WAYS TO MITIGATE IT FROM GLOBAL PERSPECTIVE

Survivability of a few plants with natural resistance after herbicide application and their reproduction followed by herbicide application on each successive generation results in herbicide resistance and this phenomenon is rampant in present day agricultural fields. The study design is thus, focused on the overall status of herbicide resistance weeds and their distribution, mechanism of herbicide resistance in weed biotypes and the practices that are adopted and need to be adopted in order to curb the resistance development mechanism. The first herbicide resistance evidence was identified in triazine resistant to common groundsel (Senecio vulgaris). However, herbicide resistance was reported against 2,4-D from Hawaii as early as 1957. Currently, 512 unique cases (species×site of action) of herbicide resistant weeds with 262 species are on light globally. Herbicide-resistant weeds have been reported in 70 countries across 92 crops, with 619 scientists from around the world contributing new cases of exposure.Wheat is the crop with the highest evidence of herbicide resistant weeds, followed by maize and rice. The sharp increase in resistant weeds from the 1980s to 2020 directs the trend as a “growing peril” on agriculture that must be addressed timely and prudently.

Production of Antioxidant Molecules in Polygonum aviculare (L.) and Senecio vulgaris (L.) under Metal Stress: A Possible Tool in the Evaluation of Plant Metal Tolerance

Plants growing on heavy metal (HM)-polluted soils show toxicity symptoms, such as chlorosis and growth reduction, and undergo oxidative stress due to the formation of reactive oxygen species (ROS). Plants overcome oxidative stress by producing a wide range of antioxidant molecules, such as polyphenols and flavonoids. The aim of the present work was to study the accumulation of these molecules in response to increasing concentrations of Cd, Cr, Cu, Ni, Pb and Zn and to assess whether they can be used as a tool in assessing metal-related stress in Polygonum aviculare and Senecio vulgaris. On average, P. aviculare shoots accumulated lower amounts of metals than S. vulgaris shoots. The uptake of all six elements was correlated and proportional to their concentration in the nutrient solution (ρ > 0.9), with the bioaccumulation factor (BAF) being >1 for most of them. The present research demonstrated that 82% of the samples showed a good correlation (|ρ| > 0.5) between the level of polyphenols, flavonoids and antioxidant activity and the metal concentration in plant shoots, confirming that the metal stress level and production of phenolic compounds having antioxidant activity were strictly connected. Nonetheless, the mere quantification of these molecules cannot identify the type of metal that caused the oxidative stress, neither determine the concentration of the stressors. The five tested populations of each species did not show any specific adaptation to the environment of origin.

Senecio vulgaris L. recorded as a new host plant for the root-knot nematode Meloidogyne luci

<p><em>Meloidogyne luci</em> is a polyphagous plant parasitic nematode species with a potential to cause great losses in agricultural production. <em>M. luci</em> can parasitize over thirty important crop species as well as ornamentals, herbs and weeds. In this report we documented a weed plant common groundsel<em> </em>(<em>Senecio vulgaris</em> L.) as a new naturally-infected host species which could act as a reservoir for this pest.</p>

The phenology of an urban street flora: a transect study

Vascular plants in flower along a fixed 3.8 km route in eight streets in a primarily residential area of urban Cambridge, U.K., were recorded at monthly intervals between January 2016 and December 2019. There was a consistent annual pattern over the four years; the number of flowering species was greatest in June or July but there were still appreciable numbers of species flowering when totals were at their lowest in February or March. Five annuals (Capsella bursa-pastoris, Euphorbia peplus, Poa annua, Senecio vulgaris, Stellaria media) and one perennial (Parietaria judaica) were very frequent and flowered from January to December. Perennial species showed greater variation through the year than annual species. In most months the number of flowering British native species exceeded the combined number of archaeophytes and neophytes, but the native total peaked earlier in the summer and then declined more rapidly than that of the introductions. The transect method appeared to be effective in identifying the main annual phenological trends and also revealed the effects of extreme weather on the patterns in some seasons.