Chrysanthemum Segetum Research Articles

Chemical Composition and Recrystallization of Epicuticular Waxes: Coiled Rodlets and Tubules

Abstract: Coiled rodlets characterize several non‐related taxa within the angiosperms. They often occur together with tubules but sometimes also with platelets or transitional forms between them. The ultrastructure chemistry, and recrystallization of epicuticular waxes of three species were investigated by high‐resolution scanning electron microscopy, gas chromatography, and mass spectrometry. Whereas Buxus sempervirens (Buxaceae) and Chrysanthemum segetum (Asteraceae) show coiled rodlets in combination with tubules, Leymus arenarius (Poaceae) exhibits tubules but no coiled rodlets. Chemical analyses reveal that the predominating β‐diketones of all species differ completely in their molecular structure. Those of the former two species are mainly substituted in carbon atom positions up to 12. In contrast, the wax of L. arenarius contains only hentriacontane‐14,16‐dione and 25‐hydroxy‐hentriacontane‐14,16‐dione. Standard solutions of the total waxes from B. sempervirens, C. segetum and L. arenarius, the purified β‐diketone fraction from C. segetum and hentriacontane‐14,16‐dione from Secale cereale were taken for recrystallization experiments under different conditions in relation to solvent and crystallization velocity. It was demonstrated that coiled rodlets grew exclusively from total waxes of B. sempervirens and C. segetum, and its β‐diketone fraction but never from L. arenarius wax or pure hentriacontane‐14,16‐dione. The recrystallization experiments pointed out that conditions, such as the chemical environment and physical factors, strongly influence the formation of coiled rodlets and tubules. It is concluded that coiled rodlets are formed by self‐assembly in close dependence on the position of β‐diketo substitution. The future role of β‐diketones in the classification of coiled rodlets within wax crystals is discussed.

Separation and Identification of Phenolic Acids from Some Species of the Asteraceae Family Using HPLC with a Diode Array Detector†

The qualitative and quantitative analysis of phenolic acids was carried out using methods of HPLC with the diode array detector (DAD). The quantitative analysis of chosen phenolic acids was carried out using the Multicomponent Analysis method (MCA). Solid-phase extraction was applied for the purification of crude extract from aerial part of three species of fam. Asteraceae (Chrysanthemum maximum Ram.(DC), Chrysanthemum segetum L., Rudbeckia laciniata L.). The choice of optimal conditions of analysis was made using DryLab+ software. The part of this work was presented at the 3rd European Congress of Pharmaceutical Sciences, Edinburgh, 15–17 September 1996.

UDP-glucose: flavonol 7-O-glucosyltransferase activity in flower extracts of Chrysanthemum segetum.

The yellow colour of Chrysanthemum segetum petals is due to the presence of the 7-O-glucosides of quercetin and particularly gossypetin (8-hydroxyquercetin). In petal extracts of C. segetum an enzyme was demonstrated which catalyzes the transfer of the glucosyl moiety of uridine 5'-diphosphoglucose (UDPG) to the 7-hydroxyl group of flavonols with gossypetin and quercetin as the best substrates. Besides flavonols flavanones and flavones were found to be glucosylated in the 7-position. The pH-optimum of the reaction highly depended on the substrate used. With quercetin as substrate, maximal enzyme activity occurred at a pH of 8.25 and a temperature of 25 degrees C, but 7-O-glucosylation also proceeded at low temperatures. Studies on temperature stability revealed, that there was no influence on the glucosylation reaction up to 40 degrees C. Higher temperatures led to a loss of enzyme activity. Using gossypetin as a substrate a similar course of temperature stability was observed. Addition of Mg2+, Ca2+ and KCN slightly stimulated 7-O-glucosylation, whereas Co2+, Cu2+, Fe2+, Hg2+, p-hydroxymercuribenzoate and N-ethylmaleimide showed a strong inhibitory effect. Additional enzymatic studies were performed with the commercial strain "Stern des Orients" where gossypetin 7-O-glucoside is restricted to the inner parts of the petals. For enzyme extracts from both parts of the petals gossypetin was found to be the most attractive substrate. In comparison to quercetin (133.4 mu kat/kg protein) an about three times higher specific activity of the 7-O-glucosyltransferase(s) was determined with gossypetin (382.1 mu kat/kg protein) as substrate, indicating that hydroxylation of quercetin in 8-position to gossypetin precedes 7-O-glucosylation.

Determination of coumarins from Chrysanthemum segetum L. by capillary electrophoresis

The separation of seven closely related coumarins, i.e., herniarin, coumarin, umbelliferone, aesculetin, dihydrocoumarin, coumarinic acid and 4-hydroxycoumarin, by capillary electrophoresis was studied using different buffer systems. The best conditions chosen were applied for the determination of coumarins in extracts from roots and aerial parts from the plant Chrysanthemum segetum.

The host range of beet yellowing viruses among common arable weed species

Twenty common arable weed species were inoculated using Myzus persicae to transmit beet yellows virus (BYV), beet mild yellowing virus (BMYV), and an isolate of beet western yellows viruses (BWYV) that did not infect beet. The viruses were detected by enzyme‐linked immunosorbent assay (ELISA), in which monoclonal antibodies distinguished between BMYV and BWYV, and by aphid transmissions to indicator host plants. Spergula arvensis, Stellaria media, Lamium purpureum and Papaver rhoeas were susceptible to all three viruses whereas Senecio vulgaris, Capsella bursa‐pastoris, Anagallis arvensis and Chrysanthemum segetum were susceptible to both BMYV and BWYV, and Matricaria perforata, Raphanus raphanistrum, Veronica persica, Urtica urens and Viola arvensis were susceptible to BWYV only. Atriplex patula, Chenopodium album and Portulaca oleracea were susceptible to BYV only. Myosotis arvensis, Silene alba, Poa annua and Solanum nigrum were not susceptible to any of the viruses. Portulaca oleracea was shown for the first time to be a host of BYV, and C. segetum a host of BMYV and BWYV. In spring 1991, 8% of weeds sampled in a field of autumn‐sown oilseed rape contained BWYV. Tests on weeds collected from an area of ‘set‐side’ adjacent to sugar beet showed that 3% contained BMYV and 3% BWYV. No sampled weeds were infected with BYV. The role of weeds in the epidemiology of sugar beet virus yellows is discussed.

Plants and Pest Control in England circa 1400–1700: A Preliminary Study

UNTIL the mid-seventeenth century, there were few who did not have a general belief in the spontaneous generation of life. This was a theory held particularly in the case of insects and weeds, in the days before the invention of the microscope. Insects were thought either to breed from decaying matter, or arise from 'dew' on leaves-an insect egg could in fact look very like a dew drop. Weeds were considered to generate from the very soil itself, not necessarily from parent plants. It was a general belief that any efforts to remove them were doomed to failure, for the soil being cursed at the Fall of Man would always produce weeds as a punishment.' Folk terms reflect this belief in such names as 'hellweed' or 'devil's guts' for the common dodder (Cuscuta epithymum) and 'ground glutton' for groundsel (Senecio vulgaris). There was considerable controversy also over the nature and spread of infection and disease which was not really settled until the time of Pasteur. The transfer of disease from person to person or plant to plant was invariably considered as a process of sympathetic magic. By the end of the seventeenth century, however, there was a great deal of biological curiosity abroad, and in Great Britain and Europe several learned societies had been set up to discuss and investigate new scientific ideas.2 Research had started upon the nature of insect pests, but plant diseases presented more problems and were not really understood until the nineteenth century. Then as now, weeds were one of the greatest pests affecting agricultural crops. The weed population was much higher before 1700 than was the case later, for sowing and weeding were all done by hand. In his Boke of Husbandry,3 Fitzherbert enumerated a number of weeds that 'doe moche harme', from which one may infer that these were some of the commonest types prevalent over four hundred years ago. Of these, thistles, docks, nettles and charlock are still with us, although charlock because of herbicides has ceased to be such a menace. However, others that he mentions, such as 'cocle' (corncockle), 'Darnod' (darnel) and dodder, we would be unlikely to see now; the same with 'Gouldes' or 'Guildes', the corn marigold (Chrysanthemum segetum). Owing to the primitive methods of winnowing, grains of darnel, other weeds and wheat were all liable to be harvested together; the more so because the wheat varieties then grown had grains which approximated more closely to those of weeds than is the case now. Hence such screening methods as then practised were inadequate to separate them. Shakespeare's reference to darnel in Henry VI: 'Want ye corn for bread? 'tis full of Darnel; do ye like the taste?' was no doubt quite topical. Darnel seeds are toxic and when ground with wheat produce a flour that can cause serious illness to those eating bread made from it. Like darnel, the purple flowering corncockle (Agrostemma githago) was another menace to crops-its seeds also contained poisonous glucosides when ground into flour. Gerard4 commented that 'what hurt it doth among come, the spoil unto bread, as well in colour, taste, and unholsomnes, is better known than desired'. The corn marigold was also a serious pest, so much so that in the reign of Henry II an ordinance was issued against the 'Guilde Weed' perhaps the earliest recorded enactment requiring the destruction of a pernicious weed. The blue cornflower (Centaurea cyanus) was a common pest in

Investigations on the Selectivity and the Metabolism of the Herbicide Bromoxynil in Plants

Summary The metabolism of 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil) was studied in plants that show a very different susceptibility to the active ingredient. Depending on the susceptibility of the corresponding plant, a graduate rate of metabolism was found. In plants extensively resistant to bromoxynil (Stellaria media, Hordeum vulgare), a rapid metabolization was observed. In Chrysanthemum segetum and Lycopersicon esculentum, both species being moderately susceptible, significant parts of the parent compound remained unchanged. Galium aparine, a very susceptible plant species, was not able to metabolize significant amounts of bromoxynil.

Plastochrone, cycle cellulaire et teneurs en ADN nucléaire du méristème caulinaire de plants de Chrysanthemum segetum soumis à deux conditions lumineuses différentes, sous une photopériode de 16 heures

Chrysanthemum segetum plants were grown from seeds under a 16-h photoperiod, at two different photon fluence rates (70 or 200 μmol m−2 s−1. At 200 μmol m−2 s−1, by comparison with 70 μmol m−2 s−1, phyllotaxy was not modified, but the plastochron decreased and the apical diameter increased by extension of the axial zone. The mean cell doubling time decreased 36.2% in the lateral zone, 29% in the axial zone, and only 13% in the rib meristem. In contrast, mitosis duration was constant. Under both light conditions, nuclei with a DNA content within the limits of the 2C range were always predominant, which means that the G1 phase of the cell cycle was the longest. At 200 μmol m−2 s−1, the shortening of the mean cell doubling time is accompanied by a reduction of the percentage of nuclei with DNA levels within the limits of the 2C range. The decrease of the latter was the most important in the axial zone and the least important in the rib meristem, showing that control of cell proliferation was obtained by means of the G1 phase of the cell cycle. Key words: Chrysanthemum segetum, cell cycle, duration of mitosis, plastochron, nuclear DNA levels, zonation.

Improved control of Stellaria media (L.) Vill in leys with Trifolium repens, using bentazone and benazolin with additives

SummaryIn pot experiments, mixtures of ammonium sulphate with surfactants or oil additives increased the phytotoxicity of commercially formulated bentazone (‘Basagran’) to Stellaria media (chickweed). Ammonium sulphate with a proprietary oil adjuvant Actipron had similar effects with benazolin potassium salt, but not with an ethyl ester formulation of benazolin. The phytotoxicity of bentazone and benazolin salts to Trifolium repens (white clover) and Lolium perenne (perennial ryegrass) was almost unaffected by these additives. In a field experiment, a mixture of ammonium sulphate with Actipron improved the control of S. media by bentazone and benazolin salts.Oils and surfactants markedly increased rates of entry of 14C bentazone into leaves of S. media, white clover and Chrysanthemum segetum. Ammonium sulphate sometimes had similar effects but on other occasions reduced uptake. In some circumstances the additives apparently interacted synergistically, to increase uptake of labelled herbicide into the leaf or to enhance its transport within the plant. In these test species, differential absorption of bentazone could not explain differences in species susceptibility, suggesting that the main cause of resistance was the ability of plants to degrade the herbicide.

Cotyledonary architecture in some Asteraceae

Cotyledonary blade is symmetrical in all the species of Asteraceae. Morphological features such as base, apex and margin vary from species to species. Venation pattern conforms to pinnate craspedodromous, pinnate camptodromous and acrodromous type. Higher order veins noticed are up to 5°. Primary vein is either stout massive, moderate or weak. The thickness of the veins gradually decreases from primary to higher order veins. Marginal ultimate venation is either incomplete, looped or fimbriate. Areoles are absent inEclipta prostrata, Chrysanthemum segetum andCalendula suffruticosa spalgarbiensis. Vein endings are either simple or branched. In some species veins lack vein endings, which may or may not be associated with tracheids. Tracheids vary in their shape and arrangement in different species. Loop formation is observed. Isolated tracheids and extension cells are observed inCalendula suffruticosa sptomentosa. All categories of veins are jacketed by parenchymatous bundle sheath.

Seed survival and periodicity of seedling emergence in twelve weedy species of Compositae

SUMMARYAchenes of 12 species of Compositae were collected in each of 3 years and mixed with the top 7.5 cm of sterilised soil which was confined in cylinders sunk in the ground outdoors and cultivated three times yearly. Seedling emergence was recorded for 5 yr and the numbers of viable seeds remaining then determined. Emergence of Arctium lappa, A. minus, Picris hieracioides, Taraxacum officinale, Sonchus arvensis and S. asper was mainly in spring. Seedlings of Chrysanthemum segetum, Lapsana communis, Anthemis cotula and Sonchus oleraceus were often most numerous in spring but also emerged at other times, while Matricaria matricarioides and M. recutita showed no consistent seasonal pattern of emergence. Except for C. segetum and A. cotula, in which there was evidence of innate dormancy imposed by the seed coat, the numbers of seedlings were greatest in the first year and thereafter decreased approximately exponentially from year to year. Few viable seeds of A. lappa or A. minus remained after 5 yr and those of T. officinale, P. hieracioides and S. arvensis accounted for less than 1.5% of the seeds sown. Seed survival was greatest in the annual weeds and ranged from 2.1% (S. asper) to 8.6% (M. matricarioides) after 5 yr.

The effect of temperature and hosts on the population dynamics of Neoaliturus fenestratus (Herrich-Schäffer) (Hemiptera: Euscelidae)

AbstractThe population dynamics of the leafhopper Neoaliturus fenestratus (H.-S.) was studied at two temperatures (20 and 25°C) and on a summer host-plant (safflower) and a winter host-plant (Chrysanthemum segetum).The life-span, reproduction and computed rates of increase were established, and it was found that the leafhopper performed best on safflower at 25°C. Delayed mating induced longer survival in both sexes. C. segetum, the winter host-plant, enabled long maintenance of the insect, although markedly reducing its rate of reproduction. The implication of these findings for the seasonal cycle of the leafhopper is discussed.

Ursachen der selektiven Wirkung der Photosynthesehemmer Phenmedipham und Bentazon/ Causes of the Selective Action of the Photosynthetic Inhibitors Phenmedipham and Bentazon

Abstract The different sensitivity of broad-leave weeds against the photosynthetic inhibitors phenmedipham and bentazon could be explained by the combined action of herbicide uptake and decomposition. In spite of fast uptake of phenmedipham by Beta vulgaris, this plant was not injured, because the herbicide was metabolized very rapidly. The transformation of phenmedipham by Galium aparine, Matricaria chamomilla, Centaurea cyanus, Stellaria media and Amaranthus retroflexus was reduced compared to Beta vulgaris. These plants survived, with the exception of Amaranthus, first of all because of a reduced uptake of the herbicide. The other weeds investigated (Galinsoga ciliala, G. parviflora, Sinapis alba, Capsella bursa-pastoris, Sinapis arvensis, Senecio vulgaris) were extremely sensitive against phenmedipham because they could not protect themselves neither by a reduced uptake nor an increased metabolism. The grass weeds Alopecurus myosuroides and Avena fatua are resistant against the herbicide because of the protected growing point and the missing basipetal translocation of the compound. Also the susceptibility of rice, soybeans, wheat and some weeds to bentazon is the result of penetration and metabolism of the herbicide in plants. Susceptible plants (Chrysanthemum segetum, Matricaria chamomilla, Xanlhium pensilvanicum) are nearly unable to detoxify bentazon. whereas in resistant plants (rice, soybeans, wheat) a substantial amount of absorbed bentazon was converted to different metabolites. Only Echinochloa crus-galli, which is more resistant, and Galium aparine, which is more susceptible, when they adsorbed the same quantity of bentazon, deviate from this general pattern.

Variations of the Cell Cycle Phases in the Shoot Apex of Chrysanthemum segetum L.

Summary The mean duration of the cell cycle and that of its component phases has been determined for different zones of the shoot apex of Chrysanthemum segetum L. by Feulgen microspectrophotometry of nuclear DNA and by the estimation of mitotic indices and labelling indices after incorporation of 14 C or 3 H-thymidine. The mean duration of mitosis is constant in all three zones of the shoot apex (axial zone, lateral zone and rib meristem), which justifies the use of mitotic indices as indicators of the cell-proliferation rate. In the axial zone and the rib meristem, the mean duration of the DNA synthetic phase does not increase in proportion to the lenghtening of the cycle, which explains the low labelling indices obtained in these regions. In all three zones, the G 2 phase is short and of roughly equivalent duration (from 6.96 to 8.06 hours). In contrast, the G 1 phase is longer and variable (from 32.24 to 114.74 hours) depending on the zone. Thus, the cell-cycle of different regions of the shoot apex of Chrysanthemum segetum consists of a period encompassing DNA synthesis, G 2 and mitosis which is approximately equivalent in each zone, and a longer, variable period corresponding to the G 1 phase, which produces the variation in the cell-cycle time observed in different zones.

Determination of Cell Cycle and DNA Synthesis Duration in the Shoot Apex of Chrysanthemum segetum L. by Double-labelling Autoradiographic Techniques

The duration of the cell cycle and the DNA synthetic phase were estimated in various zones of the shoot apex of Chrysanthemum segetum according to two different double labelling techniques. In plants growing in a 16-hour photoperiod on which the sixth leaf had been initiated, the cell cycle duration was about 130 hours in the axial zone, 50 hours in the lateral zone and 70 hours in the rib meristem. The mean duration of the synthetic phase, which was between 7.7 and 10.3 hours according to the zone, did not increase in proportion to a lengthening of the cycle either in the axial zone or in the rib meristem. These findings are discussed in relation to the estimation of the DNA content in various zones as obtained by cytophotometric measurements. They support the hypothesis of a particular lengthening of the duration of the G 1 phase in the axial zone, where the cycle is in fact most prolonged.

Duration of cell cycles in the shoot apex of Chrysanthemum segetum L.

Summary The rate of cell division in the shoot apices of young Chrysanthemum segetum plants is determined by accumulating metaphases after colchicine treatment. On an average, the cells of the lateral zone divide every 48 hours, while those of the axial zone divide three times slower (T = 130 hours). The rib meristem cells have an intermediate cycle length (T = 70 hours). A practically constant duration of mitosis (2.9 to 3.3 hours) and a parallel development of the mitotic index and the proliferation rate show that the mitotic index is a characteristic parameter of the proliferative state in the shoot apex of Chrysanthemum segetum.

Evolution of yellow flavonols in flowers of anthemideae

Yellow flavonols have been identified in flowers of Coleostephus myconis, Glossopappus macrotus, Lepidophorum repandum and Leucanthemopsis flaveola. In addition to quercetagetin, gossypetin, patuletin and quercetagetin 3′-methyl ether previously reported in other species of the tribe Anthemideae of the Compositae, spinacetin, the 6,3′-dimethyl ether of quercetagetin, has been found for the first time as a flower pigment. It occurs as the 7-glucoside in flowers of Lepidophorum repandum, the leaves of which contain patuletin 3-rhamnoside. The presence of spinacetin and the 3′-methyl ether of quercetagetin in Lepidophorum fits in with the results of recent taxonomic studies which place this genus closer to Chrysanthemum than to Anthemis. Similarly, the occurrence of quercetagetin and gossypetin in Leucanthemopsis confirms its recently proposed separation from Tanacetum. The chemical data indicate that there is an evolutionary trend in yellow flower pigmentation, with Leucanthemopsis and Chrysanthemum segetum as the two least specialized species and Lepidophorum as the most advanced.

Septoria leucanthemi . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Septoria leucanthemi . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Chrysanthemum leucanthemum, C. maximum, C. segetum . Also by inoculation on Chrysanthemum parthenium, C. roseum, Tagetes patula, Centaurea cyanus, Achillea ptarmica, Helichrysum sp., Helianthus annuus . DISEASE: Leaf spot of ox-eye daisy ( Chrysanthemum leucanthemum [Leucanthemum vulgare] ), shasta daisy ( C . maximum ) and corn marigold ( C . segetum ). The disease is sometimes referred to as leaf blotch of shasta daisy (Wormald, 1925). Symptoms appear on leaves of all ages and are of two types: dark brown circular or semicircular zonate lesions with a central sunken pale or whitish area surrounded by somewhat elevated concentric markings and measuring 0.5-2 cm wide; shot-hole spot usually appearing during extremely wet conditions, where the central pale depressed area falls off leaving behind spots with abundant pycnidia around the rim of the shot-hole. In severe cases leaves turn yellow and completely wither. GEOGRAPHICAL DISTRIBUTION: Africa (South Africa); Asia (U.S.S.R.); N. and S. America (Canada, U.S.A., Argentina); Europe (Denmark, France, Germany, Great Britain, Italy, Norway, Portugal, Spain, Yugoslavia. (Literature; Herb. IMI). TRANSMISSION: The pathogen may be transmitted by splashing rain drops and by contact. It remains in a viable condition in diseased plant debris and serves as the inoculum for the following year.

Host Specificity of the Ragwort Seed FY1

Seneca Jacobi L. is a poisonous weed that is rapidly spreading along the Pacific coast. In an effort to control this plant biologically the ragwort seed fly, Hy lemma (Pegohylemyia) Seneca ella (Meade), was selected for study from among the insects attacking ragwort. It is univoltine, and opposition in nature is very closely synchronized with the formation of the flower buds of its biennial host plant. The eggs are normally placed under the calyx bracts of the unopened buds, alongside the young florets. The larvae feed on the seeds about I month and drop to the ground to pupate when mature. In our opposition tests, no eggs were laid on the buds of 32 species or varieties of plants in the Composite, including lettuce, Lacuna saliva var. capita’s L.; safflower, Cardamoms tinctures L.; chicory, Cichorium intybus L. and 4 species of Senecio . Small numbers of eggs were laid on the buds of Senecio vulgaris L., S. cineraria DC., Cota tinctoria (L.) Gay, Chrysanthemum segetum L., Erigeron canadensis (L.) Cronq., Calendula sp., and Cichorium endivia L. These eggs either failed to hatch, or the larvae failed to complete their development, apparently because of abnormal placement of the eggs, chemical unsuitability of the host, and/or the opening of the flower head before larval development was completed. The number of eggs deposited on the Senecio species tested was in direct proportion to their phylogenetic proximity and morphological similarity to S. jacobaea . On the basis of these host specificity studies, the seed fly has now been approved for release against S. jacobaea .

The nature of the competition between cereal crops and annual weeds

In continuation of earlier work, a study has been made of the factors controlling the competition between spring-sown cereals and annual weeds. During the years 1934 and 1935 some eighteen replicated trials were carried out in widely different localities. In six experiments, observations involving some 20,000 counts were made on the cereal development. Competition between Brassica arvensis (yellow charlock) and spring barley primarily reduced the number of tillers and fertile shoots; competition on the other hand with Raphanus raphanistrum (white charlock) diminished in addition ear size. The presence of R. raphanistrum in spring oats may decrease panicle size to the same extent as shoot number. In four out of six experiments the addition of nitrogen to both the weedy and clean crop had similar effects, greatly increasing tiller production in barley and both panicle size and shoot number in oats.In six experiments nitrogenous manuring raised the yield of the weedy crop (containing either B. arvensis, R. raphanistrum or Chrysanthemum segetum (corn marigold)) to or above the level of the clean crop; n i four the yield increases were greater in the weedy than in the weed-free crop. In one experiment doubling the amount of nitrogen applied to the weedy crop did not increase the yield of oats more than the single rate, although the final yield level was considerably below that of the weed-free oats. In four other experiments additional nitrogen did not raise the yield of the weedy crop; but in only one was the yield of the clean crop increased by nitrogenous manuring.