Significant changes in plant phenology and flower production are predicted over the next century, but we know relatively little about geographic patterns of this response in many species, even those ...that potentially impact human wellbeing. We tested for variation in flowering responses of the allergenic plant, Ambrosia artemisiifolia (common ragweed). We grew plants originating from three latitudes in the Northeastern USA at experimental levels of CO sub(2) (400, 600, and 800 mu L L super(-1)). We hypothesized that northern ecotypes adapted to shorter growing seasons would flower earlier than their southern counterparts, and thus disproportionately allocate carbon gains from CO sub(2) to reproduction. As predicted, latitude of origin and carbon dioxide level significantly influenced the timing and magnitude of flowering. Reproductive onset occurred earlier with increasing latitude, with concurrent increases in the number of flowers produced. Elevated carbon dioxide resulted in earlier reproductive onset in all ecotypes, which was significantly more pronounced in the northern populations. We interpret our findings as evidence for ecotypic variation in ragweed flowering time, as well in responses to CO sub(2). Thus, the ecological and human health implications of common ragweed's response to global change are likely to depend on latitude. We conclude that increased flower production, duration, and possibly pollen output, can be expected in Northeastern United States with rising levels of CO sub(2). The effects are likely, however, to be most significant in northern parts of the region.
Although, morphologically, maize is one of the most vigorous species, with a well-developed root system and stem, lately it has become sensitive to one particular species of weeds, namely Ambrosia ...artemisiifolia. With devastating effects on agriculture, on the environment and on human health, Ambrosia artemisiifolia, comonly named ragweed, is one of the most harmful invasive species. Currently, it belongs to the category of dominant weeds in some agricultural crops, which causes significant damage in production and from observations made in the maize crop, its frequency exceeds 50 individuals on a square meter. This paper presents the results of herbicides efficacy tests regarding the control of this invasive species in maize crop. The research was carried out in the Timiș Plain, on a eutricambosoil soil type, poorly glayed, with high fertility, due to good physical and chemical properties. Of the four herbicides applied post-emergence in maize crop, the best efficacy was obtained by Glyfos Ultra herbicide, applied in doses of 3.5 l / ha, which ensured a significant reduction in coverage, of over 90% 15 days after application, while Kideka herbicide has been situated at the opposite pole, with an efficacy of about 82%. Also, the results of the same set of herbicides applied indicate very high efficacy of Glyfos Ultra herbicide, which exceeds a percent of 98% 30 days after application, while the lowest results were obtained by the herbicide named Dicash 480 SL of approximately 67%.
The impact of natural selection on the adaptive divergence of invasive populations can be assessed by testing the null hypothesis that the extent of quantitative genetic differentiation (QST) would ...be similar to that of neutral molecular differentiation (FST). Using eight microsatellite loci and a common garden approach, we compared QST and FST among ten populations of an invasive species Ambrosia artemisiifolia (common ragweed) in France. In a common garden study with varying water and nutrient levels, we measured QST for five traits (height, total biomass, reproductive allocation, above- to belowground biomass ratio, and days to flowering). Although low FST indicated weak genetic structure and strong gene flow among populations, we found significant diversifying selection (QST>FST)for reproductive allocation that may be closely related to fitness. It suggests that abiotic conditions may have exerted selection pressure on A. artemisiifolia populations to differentiate adaptively, such that populations at higher altitude or latitude evolved greater reproductive allocation. As previous studies indicate multiple introductions from various source populations of A. artemisiifolia in North America, our results suggest thatthe admixture of introduced populations may have increased genetic diversity and additive genetic variance, and in turn, promotedthe rapid evolution and adaptation of this invasive species.
To shed further light on the breeding system of ragweed, we transplanted plants from an invasive ragweed population in Changshu, Jiangsu Province, China, and used them in a series of common garden ...experiments. We studied patterns of pollen viability and stigma receptivity. We also investigated the ragweed breeding system and apomixis by measuring seed sets of different individual plants subjected to four different treatments: self-pollination, cross-pollination, open-pollination, and bagging of female capitula. Viable stigmas were observed on the second day, with viable levels reaching a maximum five to eight days after flowering. The overlapping period of pollen viability and stigma receptivity was thus about five days. Over the long run, self-incompatibility enhances ragweed diversity and adaptation to newly invaded areas; initially, however, this characteristic does not promote its spread, as it is obviously difficult for a few individual ragweed plants to form a large population via seeds relying solely o
•A model was developed for forecasting ragweed pollen emission and transport in air.•The model reproduces the main features of ragweed pollen season in Europe.•Long-range transport can bring ...allergy-relevant pollen amounts anywhere in Europe.
The paper considers the possibilities of modelling the release and dispersion of the pollen of common ragweed (Ambrosia artemisiifolia L.), a highly allergenic invasive weed, which is spreading through southern and central Europe. In order to provide timely warnings for the allergy sufferers, a model was developed for forecasting ragweed pollen concentrations in the air. The development was based on the system for integrated modelling of atmospheric composition (SILAM) and concentrated on spatio-temporal modelling of ragweed flowering season and pollen release, which constitutes the emission term.
Evaluation of the new model against multi-annual ragweed pollen observations demonstrated that the model reproduces well the main ragweed pollen season in the areas with major plant presence, such as the Pannonian Plain, the Lyon area in France, the Milan region in Italy, Ukraine and southern Russia. The predicted start of the season is mostly within 3 days of the observed for the majority of stations in these areas. The temporal correlation between modelled and observed concentrations exceeds 0.6 for the bulk of the stations.
Model application to the seasons of 2005–2011 indicated the regions with high ragweed pollen concentrations, in particular the areas where allergenic thresholds are exceeded. It is demonstrated that, due to long-range transport of pollen, high-concentration areas are substantially more extensive than the heavily infested territories.
Ophraella communa LeSage (Coleoptera: Chrysomelidae) is an important biological control agent of the common ragweed, Ambrosia artemisiifolia L., in China. Development and fecundity of O. communa, and ...hatch rate of progeny eggs were studied at five photoperiods (8:16, 10:14, 12:12, 14:10, and 16:8 L:D h). The highest survival rate of eggs was 92% at the photoperiod of 16:8 (L:D) h, and those of both larvae and pupae were observed at the photoperiod of 14:10 (L:D) h (85 and 96%). The shortest developmental durations of larvae and pupae were observed at photoperiods of 14:10 and 16:8 (L:D) h. Fecundity was 1,159-1,976 eggs per female from photoperiods of 8:16 to 16:8 (L:D) h. The hatch rates of progeny eggs were 67-92% from photoperiods of 8:16 to 16:8 (L:D) h, and photoperiods did not affect developmental duration of progeny eggs. The intrinsic rate for increase (r), the net reproductive rate (R0), and the finite rate of increase ( lambda ) reached the maximum values at 16:8 (L:D) h (0.2219 d-1, 721 hatched eggs and 1.2484 d-1, respectively) and 14:10 (L:D) h (0.2133 d-1,605.6 hatched eggs and 1.2378 d-1, respectively). Their minimum values were observed at the photoperiod of 8:16 (L:D) h, which were 0.1731 d-1, 212.2 hatched eggs and 0.1890 d-1, respectively. The shortest T value was 29.7 d at a photoperiod of 16:8 (L:D) h and the longest was 31.4 d at a photoperiod of 12:12 (L:D) h. Our study shows that O. communa could survive and reproduce successfully at different photoperiods, thus may expand its distribution to regions with different photoperiods.
Invasive alien species (IAS) can substantially affect ecosystem services and human well-being. However, quantitative assessments of their impact on human health are rare and the benefits of ...implementing IAS management likely to be underestimated. Here we report the effects of the allergenic plant Ambrosia artemisiifolia on public health in Europe and the potential impact of the accidentally introduced leaf beetle Ophraella communa on the number of patients and healthcare costs. We find that, prior to the establishment of O. communa, some 13.5 million persons suffered from Ambrosia-induced allergies in Europe, causing costs of Euro 7.4 billion annually. Our projections reveal that biological control of A. artemisiifolia will reduce the number of patients by approximately 2.3 million and the health costs by Euro 1.1 billion per year. Our conservative calculations indicate that the currently discussed economic costs of IAS underestimate the real costs and thus also the benefits from biological control.
Invasive alien plants (IAPs) substantially affect the native biodiversity, agriculture, industry, and human health worldwide. Ambrosia (ragweed) species, which are major IAPs globally, produce a ...significant impact on human health and the natural environment. In particular, invasion of A. artemisiifolia, A. psilostachya, and A. trifida in non-native continents is more extensive and severe than that of other species. Here, we used biomod2 ensemble model based on environmental and species occurrence data to predict the potential geographical distribution, overlapping geographical distribution areas, and the ecological niche dynamics of these three ragweeds and further explored the environmental variables shaping the observed patterns to assess the impact of these IAPs on the natural environment and public health. The ecological niche has shifted in the invasive area compared with that in the native area, which increased the invasion risk of three Ambrosia species during the invasion process in the world. The potential geographical distribution and overlapping geographical distribution areas of the three Ambrosia species are primarily distributed in Asia, North America, and Europe, and are expected to increase under four representative concentration pathways in the 2050s. The centers of potential geographical distributions of the three Ambrosia species showed a tendency to shift poleward from the current time to the 2050s. Bioclimatic variables and the human influence index were more significant in shaping these patterns than other factors. In brief, climate change has facilitated the expansion of the geographical distribution and overlapping geographical distribution areas of the three Ambrosia species. Ecomanagement and cross-country management strategies are warranted to mitigate the future effects of the expansion of these ragweed species worldwide in the Anthropocene on the natural environment and public health.
Display omitted
•Bioclimatic variables shape the geographical distributions of the three ragweeds.•Human activities are closely related to the invasion of the three ragweeds.•Climate change has expanded the distribution and overlapping areas of ragweeds.•Ambrosia psilostachya, and A. trifida still have the high invasion risk worldwide.
Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic annual ruderal plant and native to Northern America, but now also spreading across Europe. Air pollution and climate change will not ...only affect plant growth, pollen production and duration of the whole pollen season, but also the amount of allergenic encoding transcripts and proteins of the pollen. The objective of this study was to get a better understanding of transcriptional changes in ragweed pollen upon NO2 and O3 fumigation. This will also contribute to a systems biology approach to understand the reaction of the allergenic pollen to air pollution and climate change. Ragweed plants were grown in climate chambers under controlled conditions and fumigated with enhanced levels of NO2 and O3. Illumina sequencing and de novo assembly revealed significant differentially expressed transcripts, belonging to different gene ontology (GO) terms that were grouped into biological process and molecular function. Transcript levels of the known Amb a ragweed encoding allergens were clearly up-regulated under elevated NO2, whereas the amount of allergen encoding transcripts was more variable under elevated O3 conditions. Moreover transcripts encoding allergen known from other plants could be identified. The transcriptional changes in ragweed pollen upon elevated NO2 fumigation indicates that air pollution will alter the transcriptome of the pollen. The changed levels of allergenic encoding transcripts may have an influence on the total allergenic potential of ragweed pollen.
Display omitted
•NO2/O3 treatment of ragweed resulted in a differently expressed pollen transcriptome.•Transcripts could be categorized in different gene ontology terms.•NO2 fumigation enhanced Amb a allergen encoding transcripts of the pollen.•O3 fumigation of ragweed plants did not show this clear effect.•Transcripts with homology to allergens known from other plants could be identified.
Air pollution strongly affected the pollen transcriptome of ragweed, including also encoding Amb a, as well as encoding allergens known in other plants.
PDF
