SAIN Invasive Plant Pests Resource Collection for: Ragwort
Species (scientific name): Senecio vulgaris
| Title: Infection process and resistance in the weed pathosystem Senecio vulgaris - Puccinia lagenophorae and implications for biological control. |
| Author: Wyss-Gabriela-S {a}; Muller-Scharer-Heinz. |
| Source: Canadian-Journal-of-Botany. March, 1999; 77 (3): 361-369. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: The infection process and the level and type of resistance in the pathosystem of a native weed and a naturalized rust fungus, Senecio vulgaris L. - Puccinia lagenophorae Cooke, were examined. Four inbred plant lines from Switzerland (2), The Netherlands, and the United Kingdom, each at two stages of devolpment, were exposed to corresponding rust lines under controlled conditions. Fluorescence and light microscopy were used to assess the infection process and to quantify genotype effects. Component analysis was used to partition disease development and define the infection process. Germinating aeciospores of P. lagenophorae showed all the characteristics of the monokaryotic parasitic stage of rust infection with direct penetration and monokaryotic haustoria formation. Haustoria formed between 3 and 6 days after inoculation at low frequency. The highest level of resistance, for which differences between plant lines were detected, occurred at penetration peg formation. All the studied host-pathogen interactions were compatible. The Dutch plant line was most susceptible to all rust lines, and the Dutch rust line was the most aggressive. Susceptibility of leaves increased with the leaf developmental stage. There was a continuous range of variation in susceptibility without differential genetic interactions, thus indicating race-nonspecific quantitative resistance. The use of the more aggressive Dutch rust line may increase the level of disease, thus stimulating epidemics for biological control. Over the long term, less susceptible genotypes of the weed may be selected, although differences in susceptibility among plant lines were relatively small. |
| Title: Wintering of the biotrophic fungus Puccinia lagenophorae within the annual plant Senecio vulgaris: Implications for biological weed control. |
| Author: Frantzen-J {a}; Muller-Scharer-H {a}. |
| Source: Plant-Pathology-Oxford. Aug., 1999; 48 (4): 483-490. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Epidemics of the obligate biotrophic fungus Puccinia lagenophorae might be used to control populations of the annual plant, groundsel, Senecio vulgaris. Insight into the mechanisms of survival of P. lagenophorae over winter may help to explain the number of inoculum sources, and their strength (assessed by number and size of pustules), present in an S. vulgaris population in spring, indicating the probability and rate of progress of a subsequent epidemic. Results of the study indicated survival of the rust as mycelium within the host over winter. Survival outside the host is unlikely, because aecidiospores lost their capacity to germinate over winter and teliospores have not been reported to be infectious. Survival of S. vulgaris plants over winter was reduced by rust infection in autumn. The mortality of S. vulgaris was 30-100% depending on the date of infection. All plants infected early in autumn died but those infected late in autumn were more likely to survive. In turn, poor survival of the host impacted on the survival of P. lagenophorae over winter. Consequently, the results of the study suggest that no inoculum sources, or only a few weak ones, are present in vulgaris populations in spring. This suggestion was supported by observations of an S. vulgaris population at a ruderal site. Therefore, research on biological weed control should focus on increasing the negative impact of P. lagenophorae on S. vulgaris populations while augmenting the probability of survival of the rust over winter to start new epidemics in spring. |
| Title: Epidemic spread of the rust fungus Puccinia lagenophorae and its impact on the competitive ability of Senecio vulgaris in celeriac during early development. |
| Author: Muller-Scharer-Heinz {a}; Rieger-Stephanie. |
| Source: Biocontrol-Science-and-Technology. March, 1998; 8 (1) 59-72. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The 'system management approach' of biological weed control was applied in a small-scale field experiment with celeriac (root celery), intersown with an inbred line of the annual weed Senecio vulgaris L. The naturalized rust fungus Puccinia lagenophorae Cooke (Basidiomycetes: Uredinales), a common and widespread pathogen of S. vulgaris in Europe, was introduced into parts of the plots, and its impact on the competitive balance between the crop and weed in the presence and absence of an additional herbicide treatment was studied. Competition by S. vulgaris (at a realized density of only 50 plants/m2) during the first 10 weeks of growth was substantial, reducing the fresh weight of the celeriac bulbs by 28%. The epidemic spread of the rust fungus was relatively fast, and the time to infection was similar to that in full-area applications. Inoculation with the rust fungus strongly reduced crop losses due to competition with S. vulgaris. The fresh weight of the celeriac bulbs in plots with both S. vulgaris and the fungus was not statistically different from the celeriac yield in plots without S. vulgaris. This effect was mainly the result of the reduced biomass of S. vulgaris, and not reduced survival. Infected plants may, therefore, still contribute to soil cover and may help to suppress later germinating weed species. Older plant stages were found to be infected earlier than younger stages. No significant interactions were observed between the effects of the fungal infection and a low-dose application of the herbicide chlorbromuron on weed performance. Basic studies necessary to develop the system management approach further are discussed. |
| Title: Bromoxynil-resistant common groundsel (Senecio vulgaris). |
| Author: Mallory-Smith-Carol {a}. |
| Source: Weed-Technology. April-June, 1998; 12 (2) 322-324. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Resistance to bromoxynil and terbacil was confirmed in common groundsel collected from peppermint (Mentha piperita) fields in Oregon. This is the first reported case of a bromoxynil-resistant weed selected under field conditions. The bromoxynil rate required to reduce growth by 50% was 10 times higher for the resistant biotype than for the susceptible biotype. The bromoxynil-resistant biotype also was resistant to terbacil. |
| Title: Effects of rust infection with Puccinia lagenophorae on pyrrolizidine alkaloids in Senecio vulgaris. |
| Author: Tinney-Glenda; Theuring-Claudine; Paul-Nigel; Hartmann-Thomas {a}. |
| Source: Phytochemistry-Oxford. Nov., 1998; 49 (6) 1589-1592. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The pyrrolizidine alkaloid pattern of Senecio vulgaris, infected with the obligate fungal pathogen Puccinia lagenophorae was analysed quantitatively in comparison to noninfected controls. The fungal infection did not significantly affect the plant's total PA contents and concentrations. In comparison to the controls the fungal-infected plants showed significantly lower PA concentrations in the capitula and roots but not the shoots which contain 90% of total PAs. There was little effect on the PA composition. |
| Title: An emerging system management approach to biological weed control in crops: Senecio vulgaris as a research model. |
| Author: Mueller-Schaerer-H; Frantzen-J. |
| Source: Weed-Research. 1996; 36 (6) 483-491. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: A 'system management' approach of biological weed control in crops is proposed and compared with other methods of biological weed control. It is based on the management of a weed pathosystem in order to maximize the natural spread and disease severity of a native or naturalized pathogen. This approach may be well-suited to situations where it is necessary to control single weed species in crops, and where no immediate and complete control is required, the production of large amounts of the agent is rather limiting (e.g. when using biotrophic fungi), and/or the importation of an exotic agent is not possible. This strategy provides fundamental knowledge of underlying mechanisms of crop production systems and is aligned with the view of modem agro-ecology, in which complete eradication of weeds is not desirable. The fundamental research required for a successful application of the 'system management' approach will be illustrated with the biological control project of Senecio vulgaris L. using the naturalized rust fungus Puccinia lagenophorae Cooke. A five-step procedure, together with selected results, will be presented. Main emphasis is given to the infection window, the study of the genetic structure of the plant and pathogen population, and the management of the infection conditions (a) to maximize the spread of the disease and the impact on the plants, and (b) to minimize the development of resistant plant populations. Joint application of herbicides at low doses, additional necrotrophic pathogens, and of biochemicals interfering with the weed's defence also will be envisaged, as well as their integration into general pest control practices. In this regard, biological weed control agents have to be seen as stress factors, not as weedkillers, and biological weed control as an integral part of a well-designed pest management strategy, not as a sole cure. |
| Title: Common groundsel (Senecio vulgaris). |
| Author: Mitich-Larry-W. |
| Source: Weed-Technology. 1995; 9 (1) 209-211. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: NA |
| Title: Growth, development and nutrient accumulation in Senecio vulgaris L. and Chenopodium album L. |
| Author: Qasem-J-R; Hill-T-A. |
| Source: Weed-Research. 1995; 35 (3) 187-196. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Growth, development and nutrient accumulation in Chenopodium album and Senecio vulgaris grown in pure and mixed stands were investigated through several experiments conducted under glasshouse conditions. Results showed that the two weeds were different in their growth, development and tissue concentration and accumulation of mineral elements. The mean concentrations of nitrogen, phosphorus, potassium, calcium and magnesium in shoots of C. album were higher than those of S. vulgaris, while root concentrations of nitrogen, potassium and magnesium were lower for C. album. Marked differences between the two weed species in their responses to different potassium levels were found. C. album had a high specific requirement for potassium while the reverse was true for S. vulgaris. The competitive ability and accumulation of nutrients by C. album appeared to be greatly dependent on the availability of high potassium levels in the media. |
| Title: Senecio vulgaris L. subsp. denticulatus (O. F. Muell.) P. D. Sell and S. vulgaris subsp. vulgaris var. vulgaris on Jersey (Channel Islands). |
| Author: Comes-H-P. |
| Source: Watsonia 1995; 20 (3) 185-194. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Evidence obtained from comparative cultivation confirms that Senecio vulgaris subsp. denticulatus (Asteraceae) and its presumed derivative var. vulgaris differ consistently in a number of morphological and life history characters. Field studies on Jersey revealed that both taxa are also ecologically distinct. Subsp. denticulatus is only known from coastal areas of dune grassland where it occurs on soils which have large amounts of carbonate and low amounts of mineral nutrients. Its associates include other winter-annuals and species of Mediterranean affinity. Results obtained from soil analyses do not provide any meaningful clue to the unusual and disjunct distribution of subsp. denticulatus and several community associates within one of its natural maritime habitats (Les Quennevais). Some observations on the pollination strategy, seed production and predation damage of subsp. denticulatus are reported. In contrast to subsp. denticulatus, var. vulgaris occurs in man-disturbed inland and coastal localities throughout the island. Both taxa seem to interact along an extensive coastal hybrid zone, particularly in the disturbed area north of Les Quennevais. Progeny-analyses of both short ligulate and discoid. phenotypes from Les Quennevais showed them to produce patterns of germination, phenological and leaf shape characteristics typical of subsp. denticulatus. It is concluded that the low nutrient-supplying power of the Quennevais area is a factor of importance in limiting the distribution of the var. vulgaris genotypes to areas outside Les Quennevais. Information on the former distribution of subsp. denticulatus on Jersey suggests that its habitat is seriously endangered from progressive destruction by man. |
| Title: Interactive effects of extent and timing of defoliation, and nutrient supply on reproduction in a chemically protected annual Senecio vulgaris. |
| Author: Obeso-Jose-Ramon {a}; Grubb-Peter-J. |
| Source: Oikos- 71 (3) 506-514. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: This paper tests the proposition that the potential for regrowth in a herb after defoliation is (a) likely to be large even in species with well-developed chemical defence, and (b) unlikely to be dependent on a high root/shoot ratio, and also tests the degree to which various factors affect the extent of compensation. The response to simulated herbivory was studied in the annual Senecio vulgaris in a ten-week glasshouse experiment during summer. The following factors were considered: extent of defoliation (0, 25, 50, and 75% of leaf area), availability of mineral nutrients (three levels), timing of defoliation (two stages) and ages of tissue removed (young vs old leaves). The number of seeds per head, and the percentage of germination, showed little variation between treatments. The number of seed-containing heads, flowering heads and flower buds were recorded on two occasions separated by a week. On both occasions the number of seed-containing heads was significantly and markedly depressed in plants suffering more extensive defoliation, but on the second occasion the total reproductive performance (number of seed-containing heads, flowering heads and flower buds) showed more or less complete compensation even after 75% defoliation. This compensation was effected, at least in part, by a significantly greater allocation to reproductive parts after defoliation. At first plants with a greater nutrient supply suffered more severely from defoliation, but later they recovered completely, and the expected reproductive output was equal to that of plants that were not defoliated. Late defoliation was more detrimental, especially when old leaves were removed. There were very small differences in numbers of heads produced, or none at all, between plants having young leaves and old leaves removed. No treatment significantly over-compensated. The results are discussed in relation to the need for caution in applying the results of glasshouse experiments to the field situation, the need for multi-species comparisons, and current theory concerning potential for regrowth in plants of different habitat-types. |
| Title: Inter- and intraspecific competition of fat-hen (Chenopodium album L.) and groundsel (Senecio vulgaris L.). |
| Author: Qasem-J-R {a}; Hill-T-A. |
| Source: Weed-Research. 1994; 34 (2) 109-118. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: The responses of Chenopodium album L. and Senecio vulgaris L. to inter- and intra-specific competition were investigated in both additive and replacement series experiments under glasshouse conditions. When grown with tomato the two weed species had similar effects on shoot dry weight at low densities but S. vulgaris showed more competitive effect at higher densities. Weed density did not affect the concentrations of N,P,K, Ca or Mg in tomato shoots but dry matter and total amounts of nutrients were reduced increasingly with the increase in density of both weeds. The concentration of nutrients in the shoots of the weeds was not affected by density but dry matter yield and total nutrient accumulation per plant fell as the density increased. The concentrations of N, P, K and Mg in the shoots were higher in C. album than S. vulgaris but that of Ca was lower. In a replacement series experiment the two weed species behaved differentially. With C. album, both dry matter yield and total nutrient per plant were reduced as its proportion in the mixture increased but, with S. vulgaris, dry matter per plant increased with its proportion in the mixture. One plant of C. album grown with five S. vulgaris gave a higher shoot dry weight than when present in higher proportions or in a pure stand. In a pure stand of six plants the shoot dry weight per plant of C. album was 26% of that of one plant grown with five S. vulgaris. In comparison, the shoot dry weight of one S. vulgaris in pure stand was 120% of that of one plant grown with five C. album. The reduction in growth of C. album was associated with a greater reduction in its ability to accumulate K than other elements. The competition index (CI) of C. album in terms of dry weight decreased with its proportion in the mixture but the reverse was true for S. vulgaris. The relative competitive ability index (RCAI) of C. album was almost 3.5 times that of S. vulgaris. The results showed that differences between the weeds in inter- and intraspecific competition were closely related to the growth of their root systems. |
| Title: The occurrence of Senecio vulgaris L. var. vulgaris and S. times helwingii (S. vulgaris times S. vernalis Waldst. et Kit.) in Israel. |
| Author: Beger ex Hegi Comes-H-P. |
| Source: Israel-Journal-of-Plant-Sciences. 1994; 42 (2) 105-113. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Common Groundsel (Senecio vulgaris L. var. vulgaris (2n = 40)) is widespread in the northern hemisphere. In Israel, judging from a herbarium survey, records taken from the Israel Plant Information Center (ROTEM), and field studies, it has a restricted and widely disjunct pattern of geographical distribution, and, thus, is another example of the comparatively large group of weeds in Israel which are extremely stenochorous. The remarkable gaps in its distribution, from the Upper Golan to Mt. Carmel and to the Jerusalem area, are considered primarily to be the result of paleoclimatic changes, whereas its occurrence outside these centers of distribution is probably related to long-distance dispersal events. Natural hybridization of S. vulgaris with its closest ally, S. vernalis Waldst. et Kit. (2n = 20), results in formation of their shortly ligulate and highly sterile hybrid, S. times helwingii Beger ex Hegi (2n = 30), which is reported for the first time from the Israel area. Hybrid frequencies of 8.7 and 9.8%, respectively, were found in the two mixed populations examined in the Upper Golan. These are higher than previously reported for two localities of hybridization in Central Europe (1.1 and 1.5%), and probably indicate a closer genetic affinity of S. vulgaris var. vulgaris to S. vernalis from Israel than to S. vernalis from Central Europe. It is likely that reports of radiate variants of S. vulgaris var. vulgaris from the Israel area, none of which could be confirmed, refer to S. times helwingii. |
| Title: Resistance to Erysiphe fischeri in two populations of Senecio vulgaris. |
| Author: Bevan-J-R {a}; Crute-I-R; Clarke-D-D. |
| Source: Plant-Pathology-Oxford. 1993; 42 (4) 636-646. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: The frequency and distribution of different specific phenotypes for resistance to Erysiphe fischeri was studied in two populations of the annual weed Senecio vulgaris (groundsel) one located in Glasgow, Scotland the other located about 480 km south at Wellesbourne, England. Progeny of individual plants from the two host populations were tested for their response to up to 10 different isolates of E. fischeri, five from each location; each isolate had a different specific virulence phenotype. Most plants in each sample were susceptible to all 10 isolates. The proportion of plants whose progeny were resistant to a particular isolate ranged from 1% to 10% with the exception of resistance to one isolate that occurred with a frequency of 37% at Wellesbourne. Overall, resistance to one or more of the 10 isolates appeared to be more common in the plant population sampled at Wellesbourne than at Glasgow. Of the total number of groundsel line/isolate combinations tested, 10% involving Wellesbourne plants and 2% involving Glasgow plants were incompatible, i.e. resistant/avirulent. Both groundsel populations tended to be dominated by one or two resistance phenotypes but they were nevertheless highly heterogeneous when less frequent phenotypes were considered. This was particularly evident at Wellesbourne where 10 different resistance phenotypes were recorded amongst a total of 75 plants growing within an area of 1 m-2. |
| Title: Diversity and variation in expression of resistance to Erysiphe fischeri in Senecio vulgaris. |
| Author: Bevan-J-R {a}; Crute-I-R; Clarke-D-D. |
| Source: Plant-Pathology-Oxford. 1993; 42 (4) 647-653. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: The reactions of 20 inbred lines of Senecio vulgaris (groundsel) to inoculation with up to 10 isolates of Erysiphe fischeri (powdery mildew) were investigated in a number of repeat experiments. There was considerable variation among isolate/plant line reaction phenotypes with examples of both isolate-specific complete resistance and isolate-specific partial resistance. Some plant lines possessed high levels of partial resistance to all isolates tested. Incubation temperature and plant age influenced the infection types of some isolate/plant line combinations. In this pathosystem, complete and partial resistance, together with age-dependent and temperature-dependent resistance, appear to have evolved to facilitate a defence strategy based on a complex mosaic of interacting factors. |
| Title: Variation for virulence in Erysiphe fischeri from Senecio vulgaris. |
| Author: Bevan-J-R {a}; Crute-I-R; Clarke-D-D. |
| Source: Plant-Pathology-Oxford. 1993; 42 (4) 622-635. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Variation for virulence was investigated in two populations of Erysiphe fischeri, the cause of powdery mildew of the common annual weed Senecio vulgaris (groundsel). Infection types were recorded on detached leaf segments from 50 inbred lines of S. vulgaris following inoculation with 24 single-conidial-chain isolates of E. fischeri (12 each from two UK sites; one, at Glasgow, located about 480 km north of the other, at Wellesbourne). Mean infection types for each isolate/line combination were categorized by applying several upper limits below which combinations were considered to be incompatible. Regardless of the limit applied numerous specific virulence and resistance phenotypes could be discriminated. Virulence phenotypes were complex and all isolates were capable of colonizing and reproducing on the majority of groundsel lines. However, all isolates were completely avirulent (no reproduction) on at least one groundsel line, so no isolate was universally virulent. Plants of several groundsel lines exhibiting different resistance phenotypes were exposed to natural infection at Wellesbourne to act as mildew traps, to examine the virulence characteristics of the pathogen population. Common components of the fungus population colonized groundsel lines exhibiting resistance to only a few or none of the single-conidial-chain isolates. Rarer components of the pathogen population colonized groundsel lines with resistance to the majority or all of the isolates previously tested. These latter components of the fungus population also detected resistance in groundsel lines previously recorded as susceptible to all isolates. |
| Title: Genecological studies of groundsel (Senecio vulgaris L.): IV. Rate of development in plants from different habitat types. |
| Author: Theaker-A-J {a}; Briggs-D. |
| Source: New-Phytologist. 1993; 123 (1) 185-194. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: In order to test the hypothesis that precocious variants might be at a selective advantage in well-weeded sites, open pollinated achenes of Senecio vulgaris L. were collected in eastern Britain from three populations representative of each of five habitat types (botanic gardens, field margins, inland and coastal sandy areas and shingle beaches) some subject to weeding and others not. Progenies of a number of seed-parents (families) were grown in a garden trial, and life-history and reproductive characteristics were recorded, in particular the rate of development from sowing, with synchronous germination, to first fruiting. Populations from botanic gardens were characterized by families exhibiting precocious reproduction, a finding which supports our initial hypothesis. However, a degree of variation was detected in samples from all three botanic gardens - Oxford, Kew and Cambridge - confirming the results of an earlier study of groundsel in the University Botanic Garden, Cambridge. In contrast, samples from maritime shingle beaches had a slower rate of development. There was no evidence of population variation, suggesting that genetic drift or founder effects might be important or that there may be selection for a narrow range of phenotypes, in such areas. Furthermore, at Shingle Street, Suffolk, there was evidence of sharp local differentation between plants from the shingle beach and from an arable field margin, 50 m away, located behind sea defences. The characteristics of plants from other habitat types are discussed in relation to the apparent selection pressures imposed by different land use. Our results provide evidence of trade-offs in life-history evolution, e.g. the precocious variants were comparatively dwarf at first fruiting and shorter-lived. |
| Title: Comparing some biological and physiological differences of susceptible and resistant common groundsel (Senecio vulgaris L.). |
| Author: Chodova-Daniela; Mikulka-Jan. |
| Source: Ochrana-Rostlin 1992; 28 (4) 263-272. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Some biological and physiological differences of atrazin susceptible and atrazine resistant common groundsel (Senecio vulgaris L.) were compared. Both biotypes were differentiated by the method of slow fluorescence induction. The resistant biotype showed (4, 7, 10, 14 and 21 days after sowing) a lower percentage of germination activity than the susceptible one (the differences were not significant). However, three, four, five and six weeks after sowing, the resistant biotype had shorter aboveground parts of plants (significant differences), a lower number of leaves (significant differences five weeks after sowing), a lower fresh matter of aboveground parts (significant differences four, five and six weeks after sowing) and a lower dry matter of aboveground parts (significant differences). The resistant common groundsel showed, in comparison to the susceptible one, a lower chloroplast photochemical activity expressed by oxygen production and lower values of net photosynthesis expressed by carbon dioxide consumption. It is probable that a deterioration of chloroplasts function in relation to atrazin resistant common groundsel inhibits the growth and the productivity of the whole plant. |
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