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Brassicaceae
Terms modified by Brassicaceae Selected AbstractsDiversity and abundance patterns of phytophagous insect communities on alien and native host plants in the BrassicaceaeECOGRAPHY, Issue 6 2003Mark Frenzel The herbivore load (abundance and species richness of herbivores) on alien plants is supposed to be one of the keys to understand the invasiveness of species. We investigate the phytophagous insect communities on cabbage plants (Brassicaceae) in Europe. We compare the communities of endophagous and ectophagous insects as well as of Coleoptera and Lepidoptera on native and alien cabbage plant species. Contrary to many other reports, we found no differences in the herbivore load between native and alien hosts. The majority of insect species attacked alien as well as native hosts. Across insect species, there was no difference in the patterns of host range on native and on alien hosts. Likewise the similarity of insect communities across pairs of host species was not different between natives and aliens. We conclude that the general similarity in the community patterns between native and alien cabbage plant species are due to the chemical characteristics of this plant family. All cabbage plants share glucosinolates. This may facilitate host switches from natives to aliens. Hence the presence of native congeners may influence invasiveness of alien plants. [source] Neighbouring monocultures enhance the effect of intercropping on the turnip root fly (Delia floralis)ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2007Maria Björkman Abstract Knowledge of insect behaviour is essential for accurately interpreting studies of diversification and to develop diversified agroecosystems that have a reliable pest-suppressive effect. In this study, we investigated the egg-laying behaviour of the turnip root fly, Delia floralis (Fall.) (Diptera: Anthomyiidae), in an intercrop-monoculture system. We examined both the main effect of intercropping and the effect on oviposition in the border zone between a cabbage monoculture [Brassica oleracea L. var. capitata (Brassicaceae)] and a cabbage-red clover intercropping system [Trifolium pratense L. (Fabaceae)]. To investigate the border-effect, oviposition was measured along a transect from the border between the treatments to the centre of experimental plots. Intercropping reduced the total egg-laying of D. floralis with 42% in 2003 and 55% in 2004. In 2004, it was also found that the spatial distribution of eggs within the experimental plots was affected by distance from the adjoining treatment. The difference in egg-laying between monoculture and intercropping was most pronounced close to the border, where egg-laying was 68% lower on intercropped plants. This difference in egg numbers decreased gradually up to a distance of 3.5 m from the border, where intercropped plants had 43% fewer eggs than the corresponding monocultured plants. The reason behind this oviposition pattern is most likely that flies in intercropped plots have a higher probability of entering the monoculture if they are close to the border than if they are in the centre of a plot. When entering the monoculture, flies can pursue their egg-laying behaviour without being disrupted by the clover. As the final decision to land is visually stimulated, flies could also be attracted to fly from the intercropped plots into the monoculture, where host plants are more visually apparent. Visual cues could also hinder flies in a monoculture from entering an intercropped plot. Other possible patterns of insect attack due to differences in insect behaviour are discussed, as well as the practical application of the results of this study. [source] Trade-offs in oviposition choice?ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2007Food-dependent performance, defence against predators of a herbivorous sawfly Abstract The sawfly Athalia rosae L. (Hymenoptera: Tenthredinidae) is a feeding specialist on plant species of the Brassicaceae, which are characterised by secondary metabolites, called glucosinolates. The larvae can take up the respective glucosinolates of their hosts and concentrate them in their haemolymph to protect themselves against predators. Oviposition preferences of naïve females were tested for three species, Sinapis alba L., Brassica nigra (L.) Koch, and Barbarea stricta Andrz., and were related to larval performance patterns. Larvae were reared on either one of these plants and it was investigated how host-plant quality influences both the developmental times and growth of larvae (bottom-up) and the defence efficiency against predators (top-down). Innately, almost all adult females avoided B. stricta for oviposition and clearly preferred B. nigra over S. alba. On average, larvae developed best on B. nigra. Female larvae reached similar final body masses on all host-plant species, but males reared on S. alba were slightly lighter. The developmental time of larvae reared on B. stricta was significantly longer than on the other two plants. However, larvae reared on B. stricta were best protected against the predatory wasp Polistes dominulus Christ (Hymenoptera: Vespidae). The wasps rejected these larvae most often, while they attacked larvae reared on S. alba most frequently. Thus, larvae feeding on B. stricta theoretically run a higher risk of predation due to a prolonged developmental time, but in practice they are better protected against predators. Overall, oviposition preferences of A. rosae seem to be more influenced by bottom-up effects on larval performance than by top-down effects. [source] Athalia rosae, Plutella xylostella and Autographa gamma on arable BrassicaceaeEPPO BULLETIN, Issue 1 2005Article first published online: 27 MAY 200 No abstract is available for this article. [source] Opportunities and constraints in the adaptation of technology for the diagnosis of bacterial plant diseases , experience from Tanzania,EPPO BULLETIN, Issue 3-4 2000R. Black In order to improve diagnostic services and plant quarantine capabilities in Tanzania, the techniques of semi-selective media, the BACTID system, metabolic profiling (Biolog), indirect enzyme-linked immunosorbent assays (ELISA) and polymerase chain reaction (PCR) were assessed for suitability with the existing facilities for the diagnosis and detection of plant-pathogenic bacteria of vegetables. Field-collected samples as well as farmers' own and commercial germplasm were used in studies involving Ralstonia solanacearum, Clavibacter michiganensis subsp. michiganensis and Xanthomonas campestris pv. vesicatoria in Solanaceae and X. c. pv. campestris in Brassicaceae. Each of the techniques was used successfully with one or more of the target pathogens; each had advantages depending on the speed, sensitivity and specificity required, as well as the costs of carrying out the diagnosis. However, constraints emerged relating to the use and disposal of materials such as plastic Petri dishes and toxic substances. The more familiar underlying constraints of high cost and poor availability of consumables and erratic water and electricity supply continued to present problems. These problems will be discussed in relation to the development of an integrated and sustainable approach to the provision of routine diagnostic services. [source] Fungal biodiversity, pollen morphology and leaf surface of some native species in EgyptFEDDES REPERTORIUM, Issue 1 2001S. I. I. Abdel-Hafez Five native species of the flora of Egypt: Adonis dentata Delile, Ranunculaceae; Papaver dubium L., Papaveraceae; Matthiola longipetala (Vent.) DC., Brassicaceae; Malva parviflora L., Malvaceae; and Erodium laciniatum (Cav.) Willd., Geraniaceae have been investigated morphologically, palynologically and mycologically. The total counts of phyllosphere fungi fluctuated between 223 and 388 colonies/100 leaf segments giving maximum on Malva parviflora followed by Matthiola longipetala, Erodium laciniatum, Papaver dubium and Adonis dentata. The widest spectrum of genera (20) and species (39 and l variety) was recorded on Malva parviflora and the narrowest on Adonis dentata (9, 14). Sixty species and one variety belonging to 27 genera were collected from leaves (24 genera and 56 species and 1 variety) and anthers/pollen (16 genera and 27 species) of the five studied plants with the most frequently species were some members of Alternaria, Cladosporium, Fusarium and Mucor. Members of Aspergillus and Penicillium were prevalent only on leaves of Matthiola longipetala and Malva parviflora, while these members were infrequently recorded on leaf surfaces of Adonis dentata and Papaver dubium. Results revealed that density of hairs on the leaf surface and size of leaf blade, almost seem to be the most reliable factors of the biodiversity of the fungal spores on the studied taxa. On the other hand, reticulate or striate pollen surface had a wider spectrum of fungal biodiversity and higher densities of spores compared with echinate and scabrate surface. Pilz-Biodiversität, Pollen-Morphologie und die Blattoberfläche einiger einheimischer Arten in Ágypten Aus der Flora Ágyptens wurden die fünf einheimischen Arten Adonis dentata Delile, Ranunculaceae; Papaver dubium L., Papaveraceae; Matthiola longipetala (Vent.) DC., Brassicaceae; Malva parviflora L., Malvaceae; und Erodium laciniatum (Cav.) Willd., Geraniaceae morphologisch, palynologisch und mykologisch untersucht. Die Gesamtzahl an phyllosphären Pilzen schwankte zwischen 223 und 388 Kolonien/100 Blattsegementen. Das Maximum lag bei Malva parviflora, gefolgt von Matthiola longipetala, Erodium laciniatum, Papaver dubium und Adonis dentata. Das größte Spektrum an Gattungen (20) und Arten (39 und 1 Varietät) wurde bei Malva parviflora verzeichnet, das Minimum hingegen bei Adonis dentata (9, 14). An den fünf Arten wurden insgesamt 60 Arten und eine Varietät aus 27 Gattungen an Blättern (24 Gattungen, 56 Arten und eine Varietät) und Antheren/Pollen (16 Gattungen, 27 Arten) verzeichnet. Die häufigsten Arten gehörten zu den Gattungen Alternaria, Cladosporium, Fusarium und Mucor. Arten von Aspergillus und Penicillium wurden nur an Blättern von Matthiola longipetala und Malva parviflora nachgewiesen, während sie an den Blattoberflächen von Adonis dentata und Papaver dubium seltener waren. Aus den erzielten Resultaten ergibt sich, dass die Dichte des Haarbesatzes an der Blattoberfläche und die Größe der Blattspreite die entscheidenden Faktoren zur Biodiversität der Pilzsporen an den untersuchten Taxa sind. Anderseits kann man sagen, dass reticulate und striate Pollen im Vergleich zu einer echinaten und skabraten Oberfläche ein größeres Spektrum der Pilz-Biodiversität und eine höhere Sporendichte aufwiesen. [source] Biology and host specificity of Aulacobaris fallax (Coleoptera: Curculionidae), a potential biological control agent for dyer's woad, Isatis tinctoria (Brassicaceae) in North AmericaJOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2009E. Gerber Abstract Dyer's woad, Isatis tinctoria, a plant of Eurasian origin is a problematic weed in western North America against which a classical biological weed control programme was initiated in 2004. Three European insect species were selected as candidate agents to control this invasive species, including the root-mining weevil Aulacobaris fallax. To determine its suitability as an agent, the biology and host specificity of A. fallax were studied in outdoor plots and in the field between 2004 and 2006 in its native European range. Aulacobaris fallax is a univoltine species that lays its eggs from March to August into leaf stalks and roots of dyer's woad. Larvae mine and pupate in the roots and adults emerge from August to October. Up to 62% of the dyer's woad plants at the field sites investigated were attacked by this weevil. In no-choice host-specificity tests, A. fallax attacked 16 out of 39 species and varieties within the Family Brassicaceae. Twelve of these are native to North America. In subsequent multiple-choice tests, seven species, all native to North America, suffered a similar level of attack as dyer's woad, while none of the European species were attacked. Our results demonstrate the importance of including test plant species that have not co-evolved with the respective candidate agent. In sum, we conclude that the risk of non-target effects is too high for A. fallax to be considered as a biological control agent for dyer's woad in the United States. [source] Effect of generalist insect herbivores on introduced Lepidium draba (Brassicaceae): implications for the enemy release hypothesisJOURNAL OF APPLIED ENTOMOLOGY, Issue 7 2008K. P. Puliafico Abstract The enemy release hypothesis (ERH) states that decreased regulation by natural enemies allows plants to increase in distribution, abundance and vigour following their introduction into an exotic range. Invasive plants rarely escape herbivory entirely, and for hoary cress [Lepidium draba L. (Brassicaceae)] it has been demonstrated that generalist insect abundance is greater in its introduced North American range than in the native European range. We assessed the role of increased generalist herbivory on hoary cress using representatives of four important herbivore niches commonly found in the introduced range. We experimentally examined the density dependent impact of these herbivores individually and in combination on hoary cress in a series of greenhouse experiments. We found that defoliation of the oligophagous diamondback moth Plutella xylostella (L.) (Lep., Plutellidae) had the strongest and most consistent impact, while damage by the stem-mining weevil Ceutorhynchus americanus Buchanan (Col., Curculionidae) tended to have the highest per capita effect. Plant response to feeding by the oligophagous crucifer flea beetle Phyllotreta cruciferae (Goeze) (Col., Chrysomelidae) was minor despite obvious feeding damage, and the impact of the polyphagous tarnished plant bug Lygus hesperus Knight (Het., Miridae) was negligible. In multiple-species experiments, herbivore impacts were usually additive. In general, we found that hoary cress can tolerate high densities of oligophagous insect herbivory and effectively resisted attack by the polyphagous L. hesperus, but also the oligophagous C. americanus. Our results indicate that a combination of plant resistance and tolerance allows hoary cress to withstand increased generalist herbivore load in its introduced range, consistent with the predictions of the ERH. [source] Development of the herbivore Pieris rapae and its endoparasitoid Cotesia rubecula on crucifers of field edgesJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2006J. A. Harvey Abstract:, Several studies have reported that flowering herbs, which grow naturally or are sown adjacent to agricultural fields, may be an important source of nutrients for natural enemies. Many parasitoids readily feed on plant exudates such as floral nectar, which contain different types of sugars that enable the insects to optimize their longevity, mobility and reproductive success. However, leaf tissues of plants grown in the margins of agricultural fields may also provide food for immature stages of insect herbivores, such as caterpillars, that are in turn attacked by parasitoids. Herbivores and their parasitoids may later disperse into the crop, so the nutritional quality of surrounding plants, as this affects herbivore and parasitoid fitness, may also influence the success of biological control programmes, especially later in the season. Here, we compare the suitability of three species of cruciferous plants (Brassicaceae) on the development of Pieris rapae L. (Lep., Pieridae) and its solitary endoparasitoid, Cotesia rubecula Marshall (Hym., Bracondiae). Insects were reared on a feral population of cabbage, Brassica oleracea, on radish Raphanus sativus, which is widely sown in agricultural margins, and on hedge mustard, Sisymbrium officinale, a wild crucifer which often grows in medium to large stands along road verges and field edges. Development time in both the herbivore and parasitoid were extended on R. sativus, compared with the other two species, whereas C. rubecula completed its development most rapidly on B. oleracea. Moreover, adult butterflies and parasitoids were significantly smaller when reared on R. sativus plants. Our results reveal that differences in the quality of plants growing adjacent to agricultural fields can affect the development of key herbivores and their parasitoids. This should be borne in mind when establishing criteria for the selection of floral biodiversity. [source] Importance of long-term research in classical biological control: an analytical review of a release against the cabbage seedpod weevil in North AmericaJOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2006D. R. Gillespie Abstract:, Cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) (Col., Curculionidae), is an invasive alien pest that is spreading in North America. To aid with planning for introductions of European parasitoids in North America, we examined the status of the only classical biological control release against this pest in North America, which in 1949 introduced Mesopolobus morys, Stenomalina gracilis and Trichomalus perfectus (Hym., Pteromalidae). Weevils and parasitoids were reared in 2005 from mass collections of seedpods of Brassica napus, Brassica rapa and Raphanus raphanistrum (Brassicaceae) from 18 sites in the Fraser Valley, near Vancouver, British Columbia, Canada. Of the three European parasitoid species that were originally released, only S. gracilis was found. The predominant hymenopterous parasitoid species were Trichomalus lucidus, S. gracilis, Mesopolobus moryoides (Pteromalidae), Necremnus tidius (Eulophidae) and Eupelmus vesicularis (Eupelmidae). These constituted over 97% of the parasitoids reared, although overall parasitism was low. Only M. moryoides is clearly North American in distribution; other than S. gracilis, the remaining species were either accidentally introduced or are Holarctic in distribution. Based on these results, re-releases of M. morys and T. perfectus in North America should be considered as part of a classical biological control programme. However, redistribution of S. gracilis is not recommended at present because of potential conflicts with biological control programmes against weeds. Ongoing re-examination of classical biological control programmes can further our understanding of failure of release programmes, particularly when re-examination can be made in the light of improved taxonomy and systematics of the target and agent species. [source] Contrasting phylogeographies inferred for the two alpine sister species Cardamine resedifolia and C. alpina (Brassicaceae)JOURNAL OF BIOGEOGRAPHY, Issue 1 2009Judita Lihová Abstract Aim, We use Cardamine alpina and C. resedifolia as models to address the detailed history of disjunctions in the European alpine system. These species grow on siliceous bedrock: C. alpina in the Alps and Pyrenees, and C. resedifolia in several mountain ranges from the Sierra Nevada to the Balkans. We explore differentiation among their disjunct populations as well as within the contiguous Alpine and Pyrenean ranges, and compare the phylogeographical histories of these diploid sister species. We also include samples of the closely related, arctic diploid C. bellidifolia in order to explore its origin and post-glacial establishment. Location, European alpine system, Norway and Iceland. Methods, We employed amplified fragment length polymorphisms (AFLPs). AFLP data were analysed using principal coordinates analysis, neighbour joining and Bayesian clustering, and measures of diversity and differentiation were computed. Results, For the snow-bed species C. alpina (27 populations, 203 plants) we resolved two strongly divergent lineages, corresponding to the Alps and the Pyrenees. Although multiple glacial refugia were invoked in the Pyrenees, we inferred only a single one in the Maritime Alps , from which rapid post-glacial colonization of the entire Alps occurred, accompanied by a strong founder effect. For C. resedifolia (33 populations, 247 plants), which has a broader ecological amplitude and a wider distribution, the genetic structuring was rather weak and did not correspond to the main geographical disjunctions. This species consists of two widespread and largely sympatric main genetic groups (one of them subdivided into four geographically more restricted groups), and frequent secondary contacts exist between them. Main conclusions, The conspicuously different histories of these two sister species are likely to be associated with their different ecologies. The more abundant habitats available for C. resedifolia may have increased the probability of its gradual migration during colder periods and also of successful establishment after long-distance dispersal, whereas C. alpina has been restricted by its dependence on snow-beds. Surprisingly, the arctic C. bellidifolia formed a very divergent lineage with little variation, contradicting a scenario of recent, post-glacial migration from the Alps or Pyrenees. [source] Physiological and biochemical traits involved in the genotypic variability to salt tolerance of Tunisian Cakile maritimaAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Megdiche Wided Abstract Cakile maritima (family: Brassicaceae) was collected from three provenances belonging to different bioclimatic stages (humid, semi arid and arid) in Tunisia to study their eco-physiological and biochemical responses to salinity. Seedlings were cultivated on inert sand for 20 days under NaCl treatments (0, 100, 200, 400 mm NaCl). Plant response to salinity was provenance- and salt-dependent. At 100 mm NaCl, growth parameters (leaf biomass, area, number per plant and relative growth rate) were improved in plants from Jerba (originating from arid bioclimatic stage) compared with the control, while growth was reduced in those from Tabarka (from humid area). High salt levels (400 mm NaCl) decreased the plant growth in the three provenances, but plants in Tabarka were the most salt sensitive. The relative salt tolerance of plants from Jerba and Bekalta provenances was associated with low levels of malondialdehyde as well as of electrolyte leakage and endoproteolytic activity. Salt reduced leaf hydration, the decrease in water content being dose-dependent and more pronounced in Tabarka. Increase in salinity led to significant increase in leaf succulence and decrease in leaf water potential, especially in Jerba plants. The plants from the latter displayed the highest leaf levels of Na+ and Cl,, proline, soluble carbohydrates, soluble proteins, and polyphenols. Overall, the higher salt tolerance of plants from Jerba provenance, and to a lower extent of those from Bekalta, may be partly related to their better capacity for osmotic adjustment and to limit oxidative damage when salt-challenged. Résumé Cakile maritima a été collecté (famille des Brassicaceae) dans trois provenances appartenant à des étages bioclimatiques différentes (humide, semi-aride et aride) de la Tunisie, dans le but d'étudier leurs réponses éco-physiologique et biochimique à la salinité. Des plantules ont été cultivées dans du sable inerte pendant vingt jours avec des doses croissantes de NaCl (0, 100, 200 et 400 mm NaCl). La réponse de Cakile maritima dépend de la provenance et de la salinité du milieu. A 100 mm de NaCl, les paramètres de croissance (biomasse, surface et nombre des feuilles par plante ainsi que le taux de la croissance relative) ont été améliorés chez Djerba (zone bioclimatique aride) par comparaison aux plantes témoins, tandis que la croissance a été réduite chez Tabarka (zone humide). A la plus forte dose de sel (400 mm), une réduction de la croissance des trois provenances a été enregistrée avec une nette sensibilité chez les plantes de la provenance Tabarka. La tolérance relative des deux provenances Djerba et Bekalta est associée à une faible teneur en malondialdéhyde ainsi qu'une fuite d'électrolyte et activité endo-protéolytique modérées. Le traitement salin a réduit l'hydratation des feuilles et cette diminution du contenu en eau est dose-dépendante et elle est plus prononcée chez Tabarka. En outre, l'augmentation de la salinité du milieu a entrainé une élévation de la succulence des feuilles concomitante à une diminution du potentiel hydrique notamment chez Djerba. Les plantes de cette dernière ont été les plus riches en Na+ et Cl - , en proline, carbohydrates, en protéines solubles et en polyphénols. En général, la tolérance au sel de la provenance Djerba, et à moindre degré Bekalta, est en partie reliée à la meilleure capacité d'ajustement osmotique et la limitation des dommages oxydatifs sous stress salin. [source] Influence of sulphur plant nutrition on oviposition and larval performance of the cabbage root flyAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2005Cristina Marazzi Abstract 1,Oilseed rape plants (Brassica napus) (L.) (Brassicaceae) were grown under different levels of sulphur supply and tested for the oviposition preference and larval performance of cabbage root flies Delia radicum (L.) (Diptera: Anthomyiidae). 2,Adult females laid more than three-fold as many eggs on control Sn (normal field concentration) than on sulphur-free S0 plants. By contrast, no significant difference was observed between control and double normal concentration (S+) plants. 3,The larval performance was evaluated using three additional, intermediate sulphur levels between S0 and Sn, and the plants were infected with equal numbers of eggs. The percentage pupation at the end of larval feeding ranged from 6% (S0) to 32% (Sn or S+) and the average number of pupae, or of emerging flies, was significantly correlated with sulphur application. 4,The weight of emerging males and females was correlated with plant sulphur supply. 5,The duration of development from eggs to adult emergence was approximately 2 days longer in females than in males. Females originating from plants with a normal or higher sulphur supply tended to emerge 1,2 days earlier. [source] Indole Glucosinolates and Camalexin do not Influence the Development of the Clubroot Disease in Arabidopsis thalianaJOURNAL OF PHYTOPATHOLOGY, Issue 6 2008J. Siemens Abstract Root galls of Brassicaceae caused by Plasmodiophora brassicae are dependent on increased auxin and cytokinin formation. In this study we investigated whether indole glucosinolates are involved in indole-3-acetic acid (IAA) biosynthesis in root galls, by using a genetic approach. The cytochrome P450 enzymes, CYP79B2 and CYP79B3, convert tryptophan to indole-3-acetaldoxime (IAOx), which is a precursor for indole glucosinolates and the phytoalexin camalexin in Arabidopsis thaliana. Root galls of the Arabidopsis ecotypes Wassilewskija (WS) and Columbia (Col) accumulated camalexin, WS at levels up to 320 ,g/g dry weight. By contrast, camalexin was absent in root galls of cyp79b2/b3 double mutants. Infection rate and disease index as a measure of club development in mutant and wild-type plants of the two ecotypes were investigated and no differences were found in gall formation. This demonstrates that camalexin is an ineffective inhibitor of P. brassicae and indole glucosinolates are not the source of elevated levels of IAA in galls, because free IAA levels in mutant galls were comparable with those in wild type. [source] The Interaction of Plasmodiophora brassicae and Arabidopsis thaliana: Parameters for Disease Quantification and Screening of Mutant LinesJOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2002J. Siemens Abstract The soil-borne obligate pathogen Plasmodiophora brassicae causes clubroot disease in species of Brassicaceae, including Arabidopsis thaliana. The host,pathogen interaction was studied with respect to the age of the plant at the time point of inoculation and to different infection pressures in order to establish a standardization of infection parameters and evaluation of disease extent for A. thaliana lines. Spore number per root weight, root and shoot weight of inoculated and non-inoculated plants as well as infection rate and disease index (DI) were analysed and correlated. The disease extent of different lines was comparable as measured by the relation of root weight of inoculated and non-inoculated plants (Ri/Rni index) and the DI. Most of the 71 screened A. thaliana lines turned out to be susceptible. However, the mutant lines tu8, tu3, det1-1, and rhd3-1 showed a certain degree of tolerance under specific culture conditions. The reactions of rhd3-1 indicate that hypertrophy is a prerequisite for maturation of the pathogen. The reactions of the tu3 and tu8 mutants indicate a role of indole glucosinolates and indole-3-acetonitrile/IAA in development of clubroot disease. [source] Sulfur and nitrogen supply influence growth, product appearance, and glucosinolate concentration of broccoliJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2007Ilona Schonhof Abstract The effects of insufficient and optimal sulfur (S) and nitrogen (N) supply on plant growth and glucosinolate formation were studied under controlled experimental conditions in broccoli "Monaco". Here, we report on the interaction between S and N supply, plant growth, and quality parameters and discuss the relevance of this interaction in relation to crop-management strategies. Broccoli plants supplied with insufficient amounts of S or N showed typical deficiency symptoms and yield decreases. In contrast, total glucosinolate concentrations were high at insufficient N supply, independent of the S level, and low at insufficient S supply in combination with an optimal N supply. This was mainly due to the presence of the alkyl glucosinolates glucoraphanin and glucoiberin. Furthermore, with S concentrations above 6 g (kg DM),1 and an N : S ratio lower than 10:1, the glucosinolate concentrations were on average around 0.33 g (kg fresh matter),1 and differed significantly from those plants characterized by an S concentration below 6 g (kg DM),1 and an N : S ratio above 10:1. In addition, N : S ratios between 7:1 and 10:1 promoted plant yield and enhanced overall appearance. Therefore, to produce broccoli (and potentially other Brassicaceae) with higher crop yields and enhanced product quality in the field, it is vital to establish the optimal S and N nutritional status of the plant and to integrate this information into crop-management strategy programs. [source] Notes on the family Brassicaceae in ChinaJOURNAL OF SYSTEMATICS EVOLUTION, Issue 3 2009Dmitry A GERMAN Abstract A critical revision of the collections of Brassicaceae in some Chinese (PE, XJA, XJBI, XJFA, XJNM, XJU) and foreign (LE, P) herbaria is made. One genus, Neurotropis (DC.) F. K. Mey., and 11 species, Alyssum szarabiacum Nyár., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii D. German, Erysimum mongolicum D. German, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa (Fisch. & Mey.) F. K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha (Botsch. & Vved.) Al-Shehbaz & S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus (Bunge) O. E. Schulz, Dontostemon perennis C. A. Mey., Goldbachia torulosa DC., Lepidium amplexicaule Willd., Neotorularia brevipes (Kar. & Kir.) Hedge & J. Léonard, and Parrya stenocarpa Kar. & Kir., are confirmed to occurr in China. Five species, Dontostemon integrifolius (L.) C. A. Mey., Draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes (Bunge) Botsch., are reported as novelties for some provinces in China, and Strigosella hispida (Litv.) Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O'Kane & Price, and four species, Draba huetii Boiss., Eutrema halophilum (C. A. Mey.) Al-Shehbaz & S. I. Warwick, Galitzkya spathulata (Steph. ex Willd.) V. Bocz., and Pseudoarabidopsis toxophylla (Bieb.) Al-Shehbaz, O'Kane & Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens (DC.) C. A. Mey., Strigosella hispida (Litv.) Botsch., and Strigosella scorpioides (Bunge) Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing characters from related species already known in China are discussed. Other comments are provided where needed. [source] A new antimicrobial peptide isolated from Oudneya africana seedsMICROBIOLOGY AND IMMUNOLOGY, Issue 12 2009Riadh Hammami ABSTRACT Oudneya africana R. Br. (Brassicaceae), a wild-growing plant in the arid region of Tunisia, is used in ethno-medicinal treatment of microbial infections. Validation of ethno-therapeutic claims pertaining to the plant was sought by investigating its antimicrobial activity. A proteinaceous extract of the seeds, called AS-3000, showed activity against various organisms including L. monocytogenes, E. coli, B. subtilis, E. hirae, P. aeruginosa, S. aureus and C. albicans. Extract AS-3000 exhibited a synergistic effect against L. ivanovii when combined with vancomycin or chloramphenicol. The post-antibiotic inhibitory effect of the ampicillin/AS-3000 combination was 2.3-fold greater than for the antibiotic alone. The mode of action of AS-3000 on Listeria and Escherichia was visible using SEM. These results support the use of O. africana for treating microbial infections. [source] Genetic differentiation and reproductive isolation of a naturally occurring floral homeotic mutant within a wild-type population of Capsella bursa-pastoris (Brassicaceae)MOLECULAR ECOLOGY, Issue 12 2009STEFFEN HAMEISTER Abstract Apart from the common floral architecture in Brassicaceae, variation in flower morphology occurs in several genera within the family and is considered to affect speciation processes. We analysed genetic differentiation and flowering time variation of two floral variants of Capsella bursa-pastoris, the Spe variant and the wild-type, which occur sympatrically in a vineyard in southwest Germany. The Spe variant is characterized by an additional whorl of stamens instead of petals and was formerly classified as an independent taxon ,Capsella apetala' Opiz. Amplified fragment length polymorphism and allozyme analysis revealed a substantial genetic differentiation of the two floral variants and a higher genetic variation within the wild-type subpopulation compared with the Spe subpopulation. The low genetic variation in the mutant provided evidence of a recent local origin or recent introduction. Flowering time analysis indicated that, within the analysed population, the Spe variant flowers significantly later than the wild-type (P < 0.001). We conclude that the evolution and persistence of Spe within a wild-type population is facilitated by high selfing rates and been enhanced by a shift in flowering phenology. Hence, our data provide substantial evidence that the Spe phenotype has established itself as an isolated entity within a wild-type population and may thus serve as a model for the analysis of the evolutionary significance of homeotic mutants in wild populations. [source] Consistent geographic structure among multiple nuclear sequences and cpDNA polymorphisms of Cardamine nipponica Franch. et Savat. (Brassicaceae)MOLECULAR ECOLOGY, Issue 13 2008HAJIME IKEDA Abstract Molecular phylogeography has inferred the history of differentiation between regions and/or among populations following the Pleistocene climatic oscillations, mostly based on the genetic structure of organelle DNA. However, such genetic structure only reflects the history of a single gene, and studies based on single-copy genes of nuclear DNA (nDNA) are required for phylogeography, although their efficiency remains unclear. To examine the utility of nDNA loci, the genetic structures of three genes from Cardamine nipponica, which is closely related to the model species Arabidopsis thaliana, were elucidated: the nDNA genes DET1, PHYA, PHYE, as well as chloroplast DNA (cpDNA). In 279 individuals collected from throughout the range of the species, strong genetic differentiation between northern and central Japan was found for all loci. This result suggested that populations in central Japan experienced a different history from those in northern Japan during the Pleistocene climatic oscillations. In addition, the evidence of refugia at the edges of the distribution, where the genetic structure was less influenced by colonization following range expansion, was shown for several loci. The specific genetic structure within the southernmost populations of northern Japan suggested that this region was also isolated during range expansion. Hence, the consistent history among loci and a more detailed history from several loci indicated that cpDNA can represent the history of vicariance and demonstrated the efficiency of single-copy nuclear genes in phylogeography. [source] Nuclear and chloroplast microsatellites reveal extreme population differentiation and limited gene flow in the Aegean endemic Brassica cretica (Brassicaceae)MOLECULAR ECOLOGY, Issue 23 2007KRISTINA EDH Abstract Nuclear and chloroplast microsatellite markers were used to study population structure and gene flow among seven Cretan populations of the Aegean endemic plant species Brassica cretica (Brassicaceae). Both nuclear and chloroplast markers revealed exceptionally high levels of population differentiation (overall FST = 0.628 and 1.000, respectively) and relatively little within-population diversity (overall HS = 0.211 and 0.000, respectively). Maximum-likelihood estimates of directional migration rates were low among all pairs of populations (average Nm = 0.286). There was no evidence that differences in flower colour between populations had any influence on historical levels of gene flow. In addition, a haplotype network showed that all five chloroplast haplotypes found in the sample were closely related. Together, these results suggest that current patterns of diversification in B. cretica are mainly a result of genetic drift during the last half million years. The main conclusions from the present study are consistent with the prevailing hypothesis that plant diversification in the Aegean region is driven by random rather than adaptive differentiation among isolated populations. [source] Bayesian inference of evolutionary history from chloroplast microsatellites in the cosmopolitan weed Capsella bursa - pastoris (Brassicaceae)MOLECULAR ECOLOGY, Issue 14 2005ALF CEPLITIS Abstract Besides showing an extraordinary degree of phenotypic variability, Capsella bursa-pastoris (Brassicaceae) is also one of the world's most common plant species and a serious weed in many countries. We have employed a coalescent-based Bayesian analysis of chloroplast microsatellite data to infer demographic and evolutionary parameters of this species. Two different demographic models applied to data from seven chloroplast microsatellite loci among 59 accessions show that the effective population size of C. bursa-pastoris is very small indicating a rapid expansion of the species, a result that is in accordance with fossil and historical data. Against this background, analysis of flowering time variation among accessions suggests that ecotypic differentiation in flowering time has occurred recently in the species' history. Finally, our results also indicate that mononucleotide repeat loci in the chloroplast genome can deteriorate in relatively short periods of evolutionary time. [source] Molecular signals for Late Tertiary/Early Quaternary range splits of an Eurasian steppe plant: Clausia aprica (Brassicaceae)MOLECULAR ECOLOGY, Issue 9 2004A. FRANZKE Abstract Several vegetation belts stretch continuously from Europe to Asia, taiga and steppe being most prominent. Numerous plant species within these belts share a conspicuous distribution area, which is longitudinally contracted or disrupted approximately along longitude 70° E. To date no hypothesis for this intriguing distribution pattern has been put forward. We detected molecular footprints in the contemporary genetic composition in nuclear DNA (ITS1, ITS2) and chloroplast DNA (trnL,trnF spacer region) of the steppe element Clausia aprica (Brassicaceae) providing evidence for a severe longitudinal range split and genetic differentiation east of the Ural Mountains about 1 million years ago caused by Quaternary climatic oscillations. Clausia aprica provides the first phylogeographical analysis on the intraspecific evolution of an Eurasian steppe plant. [source] Hybridization and Rorippa austriaca (Brassicaceae) invasion in GermanyMOLECULAR ECOLOGY, Issue 7 2003W. Bleeker Abstract Introgressive hybridization between the invasive Rorippa austriaca and the native R. sylvestris in Germany has been studied using chloroplast DNA (trnL intron) and amplified fragment length polymorphism. Three hybrid zones between the invasive and native species were located in the Ruhr Valley (Mülheim) and at the River Main near Würzburg (Randersacker, Winterhausen). In each hybrid zone hybridization was indicated by additivity of region-specific amplified fragment length polymorphism markers proving independent hybridization events. The hybrids were either morphologically intermediate (R. × armoracioides) or were close to R. sylvestris. The trnL intron of R. austriaca is characterized by a species-specific deletion. This diagnostic chloroplast marker of R. austriaca was detected in three individuals of R. sylvestris providing evidence for introgression of the invasive chloroplast into the native species. Bidirectional introgression of R. austriaca markers into R. sylvestris and of R. sylvestris markers into R. austriaca was detected in the amplified fragment length polymorphism analysis. Some of the invasive R. austriaca populations showed high within-population variation. A possible association among introgression, within-population variation and invasion success is discussed. The morphologically intermediate hybrid R. × armoracioides is currently spreading in northern Germany. It forms large populations without its parent species R. austriaca and R. sylvestris. It is concluded that hybridization between invasive R. austriaca and native R. sylvestris may lead to the evolution of a new invasive species R. × armoracioides. [source] Ten microsatellite loci from Solms-laubachia eurycarpa (Brassicaceae)MOLECULAR ECOLOGY RESOURCES, Issue 5 2008JIPEI YUE Abstract Solms-laubachia eurycarpa is a medicinal herb endemic to the Hengduan Mountains region of south-central China. We screened a partial genomic library enriched for microsatellites and characterized 10 polymorphic loci for S. eurycarpa. The number of alleles per locus ranged from five to 15, with an average of 9.6. The observed and expected heterozygosities ranged from 0.2 to 0.725 and from 0.585 to 0.871, respectively. Amplification in closely related taxa was successful for most loci. The results indicate significant potential for the utility of these markers in studying the population genetics of S. eurycarpa and related species. [source] Polymorphic microsatellite markers in polyploid Lepidium draba L. ssp. draba (Brassicaceae) and cross-species amplification in closely related taxaMOLECULAR ECOLOGY RESOURCES, Issue 1 2005M.-C. BON Abstract Heart-podded hoary cress, Lepidium draba L. ssp. draba (Brassicaceae) is a noxious invasive weed in the USA. At present, efficient biological control of this Eurasian native weed in the USA is hampered by lack of knowledge of its population genetic structure and colonization process. Here, we describe the development of 11 polymorphic microsatellite markers that also reveal the polyploidy of this weed. Successful cross-species amplification highlights the possibility of using these markers for genetic studies in other closely related species. [source] Transferability and genome specificity of a new set of microsatellite primers among Brassica species of the U triangleMOLECULAR ECOLOGY RESOURCES, Issue 1 2002Andrew J. Lowe Abstract We present a new set of 12 highly polymorphic simple sequence repeat primer sequences for use with Brassica species. These new primers, and four from A.K.S. SzewcMcFadden and colleagues, were tested in four Brassica species (B. rapa, B. napus, B. oleracea and B. nigra). Most primers successfully amplified products within all species and were polymorphic. Due to the risk of gene flow from GM oilseed rape to its wild relatives, hybrid formation in the Brassicaceae is of great interest. We identify six primer pairs as specific to the A, B or C genomes that could be used to identify such hybrids. [source] Identification of desulphoglucosinolates in Brassicaceae by LC/MS/MS: Comparison of ESI and atmospheric pressure chemical ionisation-MSMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 12 2007Nadine S. Zimmermann Abstract In order to develop a sensitive method for the detection of desulphoglucosinolates by HPLC-MS, the two most common interfaces for HPLC-MS, atmospheric pressure chemical ionisation (APCI) and ESI, were compared. While working with the APCI-interface the evaporation temperature and corona amperage were optimised. In doing so 300°C and 6 ,A proved to be most suitable for aliphatic and indole desulphoglucosinolates. The use of formic acid instead of water in the eluent in HPLC-ESI-MS measurements increased the sensitivity for the indole desulphoglucosinolates in the presence of 1 mM formic acid, while the sensitivity for the aliphatic desulphoglucosinolate desulphoglucoraphanin was substantially increased by the presence of 5 mM formic acid. Using an Agilent ion trap, two optimisation procedures for the MS parameters, smart and expert mode, were available. In smart mode the software optimises several parameters automatically, which is much more time efficient than expert mode, in which the optimisation is done manually. It turned out that ESI-MS is most sensitive in smart mode, while for APCI-MS a higher sensitivity could be gained using the expert mode. Comparing both interfaces, APCI-MS was more sensitive than ESI-MS. However, no additional information, in terms of structure determination, was obtained by APCI-MS. [source] Specific resistances against Pseudomonas syringae effectors AvrB and AvrRpm1 have evolved differently in common bean (Phaseolus vulgaris), soybean (Glycine max), and Arabidopsis thalianaNEW PHYTOLOGIST, Issue 4 2010Nicolas W. G. Chen Summary ,In plants, the evolution of specific resistance is poorly understood. Pseudomonas syringae effectors AvrB and AvrRpm1 are recognized by phylogenetically distinct resistance (R) proteins in Arabidopsis thaliana (Brassicaceae) and soybean (Glycine max, Fabaceae). In soybean, these resistances are encoded by two tightly linked R genes, Rpg1-b and Rpg1-r. To study the evolution of these specific resistances, we investigated AvrB- and AvrRpm1-induced responses in common bean (Phaseolus vulgaris, Fabaceae). ,Common bean genotypes of various geographical origins were inoculated with P. syringae strains expressing AvrB or AvrRpm1. A common bean recombinant inbred line (RIL) population was used to map R genes to AvrRpm1. ,No common bean genotypes recognized AvrB. By contrast, multiple genotypes responded to AvrRpm1, and two independent R genes conferring AvrRpm1-specific resistance were mapped to the ends of linkage group B11 (Rpsar-1, for resistance to Pseudomonas syringae effector AvrRpm1 number 1) and B8 (Rpsar-2). Rpsar-1 is located in a region syntenic with the soybean Rpg1 cluster. However, mapping of specific Rpg1 homologous genes suggests that AvrRpm1 recognition evolved independently in common bean and soybean. ,The conservation of the genomic position of AvrRpm1-specific genes between soybean and common bean suggests a model whereby specific clusters of R genes are predisposed to evolve recognition of the same effector molecules. [source] Nickel hyperaccumulation as an elemental defense of Streptanthus polygaloides (Brassicaceae): influence of herbivore feeding modeNEW PHYTOLOGIST, Issue 2 2005Edward M. Jhee Summary ,,No study of a single nickel (Ni) hyperaccumulator species has investigated the impact of hyperaccumulation on herbivores representing a variety of feeding modes. ,,Streptanthus polygaloides plants were grown on high- or low-Ni soils and a series of no-choice and choice feeding experiments was conducted using eight arthropod herbivores. Herbivores used were two leaf-chewing folivores (the grasshopper Melanoplus femurrubrum and the lepidopteran Evergestis rimosalis), a dipteran rhizovore (the cabbage maggot Delia radicum), a xylem-feeder (the spittlebug Philaenus spumarius), two phloem-feeders (the aphid, Lipaphis erysimi and the spidermite Trialeurodes vaporariorum) and two cell-disruptors (the bug Lygus lineolaris and the whitefly Tetranychus urticae). ,,Hyperaccumulated Ni significantly decreased survival of the leaf-chewers and rhizovore, and significantly reduced population growth of the whitefly cell-disruptor. However, vascular tissue-feeding insects were unaffected by hyperaccumulated Ni, as was the bug cell-disruptor. ,,We conclude that Ni can defend against tissue-chewing herbivores but is ineffective against vascular tissue-feeding herbivores. The effects of Ni on cell-disruptors varies, as a result of either variation of insect Ni sensitivity or the location of Ni in S. polygaloides cells and tissues. 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