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At least 19 recordsLinked to original sources

Primula pingwuensis (Primulaceae), a new species in Primula sect. Auganthus from Sichuan, China.

Primula pingwuensis sp. nov., a new species of Primula sect. Auganthus from Sichuan, China, is described. It resembles P. sinensis in having palmately lobed leaves and multi-whorled inflorescences but differs by its multi-branched stems, more densely short-pubescent surfaces, thicker chartaceous leaves, narrower leaf blades, and indistinct translucent nectar guides. A taxonomic key covering all nine known species of Primula sect. Auganthus is compiled herein to support field morphological discrimination. A chloroplast genome-based phylogeny shows that P. pingwuensis is sister to P. rongrong, and this clade is sister to P. fujiangensis. Incongruence between morphology and molecular phylogeny is observed within the section. Leaf-lobing patterns have undergone multiple independent evolutionary transitions during adaptive radiation in karst habitats, indicating that a few morphological traits cannot be used to reliably infer interspecific relationships. The new species is assessed as Data Deficient (DD) following IUCN criteria, owing to the lack of long-term observations of its threat status and population dynamics. This study provides new data for the taxonomy and evolution of Primula sect. Auganthus.

Primula↗

Plant regeneration from cell suspension-derived protoplasts of Primula malacoides and Primula obconica.

Protoplasts were isolated from cell suspension cultures of Primula malacoides cv. 'Lovely Tokyo' and P. obconica cv. 'Aalsmeer Giant White'. P. obconica protoplasts were embedded in 0.1% (w/v) gellan gum-solidified discs comprising MS medium supplemented with 3 mg/l of 2,4-D or picloram, 0.1 mg/l of zeatin, 0.2 M glucose and 0.2 M mannitol, and surrounded by a liquid medium of the same composition except for the addition of 0.1% (w/v) activated charcoal. The protoplasts formed visible colonies, which were transferred to the regeneration medium containing 30 g/l of sucrose, 0.1 mg/l of picloram and 2 mg/l of zeatin for shoot induction. P. malacoides protoplasts formed visible colonies when cultured in disc culture using 0.1% (w/v) gellan gum-solidified MS medium containing 5 mg/l of 2,4-D, 1 mg/l of NAA, 0.1 mg/l of zeatin and 0.4 M glucose. Small calli were transferred to MS medium supplemented with 5 mg/l of zeatin for shoot regeneration. The shoots of both species readily rooted on plant growth regulator-free 1/2 MS medium and successfully acclimatized to greenhouse conditions. The protoplast-derived plants showed some alterations in morphological characteristics from those of the in-vitro-germinated control plants.

Journal Article↗

Contact dermatitis due to hardy Primula species and their cultivars.

For more than 100 years, it has been widely held that of all the Primula species to cause allergic contact dermatitis, P. obconica is the most likely culprit, particularly in Northern Europe. The main sensitizer is primin, but other sensitizers are reported. Other species are rarely implicated, but we suspect from our discussions with Primula growers that this is probably a consequence of under-reporting. Moreover, cutaneous reactions to other hardy Primula species and cultivars would appear to be milder and may sometimes be associated with a state of tolerance after repeated handling. With the co-operation of members of the Midland and West Section of the National Auricula and Primula Society of the UK, 462 questionnaires were sent out to members and 316 replies were returned (response rate 68.4%) with data on 320 growers. 84 out of a total of 320 (26.25%) attributed a cutaneous reaction to Primula species, whereas 236 (73.75%) reported no reaction. Of the 84 who reported reactions, 48 suspected P. auricula, 34 P. obconica, 10 P. vulgaris, 5 P. allionii, 3 P. marginata and 2 P. forrestii 19 believed that they had reacted to 2 or more species of Primula. Our study suggests that Primula species other than P. obconica may elicit dermatitis more frequently than previously recorded.

Aged↗

A comparison of early floral ontogeny in wild-type and floral homeotic mutant phenotypes of Primula.

Primula flowers are heteromorphic with individual plants producing either pin-form or thrum-form flowers. We have used scanning electron microscopy to observe early development of wild-type flowers of primrose (Primula vulgaris), cowslip (P. veris), and the polyanthus hybrid (P. x tommasinii x P. vulgaris). Floral ontogeny in Primula is different from that observed in the well-studied models Antirrhinum majus and Arabidopsis thaliana and our studies reveal morphological landmark events that define the sequence of early floral development in Primula into specific stages. Pin-form and thrum-form flowers are indistinguishable during early development with differentiation of the two floral morphs occurring beyond the differentiation of floral organs. Early ontogeny of flowers with homeotic mutant phenotypes was also studied to determine the timing of developmental reprogramming in these mutants. Phenotypes studied included Hose in Hose and Jack in the Green that develop petaloid sepals and leafy sepals, respectively, and Jackanapes plants that carry both these dominant mutations. Recessive double and semi- double flowers that produce additional whorls of petals and/or stamens in place of carpels were also studied. We describe a previously undocumented recessive Primula mutant phenotype, sepaloid, that produces sepals in place of petals and stamens, and a new non-homeotic, dominant mutant phenotype Split Perianth, in which sepals and petals fail to fuse to form the typical calyx and corolla structures. The molecular basis of these mutant phenotypes in relation to the ABC model is discussed.

Flowers↗

Molecular characterization of DNA sequences from the Primula vulgaris S-locus.

Primula species provide possibly the best known examples of heteromorphic flower development and this breeding system has attracted considerable attention, including that of Charles Darwin. However, despite considerable recent advances in molecular genetics, nothing is known about the molecular basis of floral heteromorphy. The first molecular marker for the Primula S-locus is reported here. This DNA sequence was identified by random amplification of polymorphic DNA (RAPD)-PCR, further defined as a sequence characterized amplified region (SCAR) marker, and subsequently shown to correspond to a restriction fragment length polymorphism (RFLP) that is linked to the thrum allele of the Primula S-locus. The sequence of 8.8 kb of genomic DNA encompassing this thrum-specific RFLP is presented. Analysis of this DNA reveals a highly repetitive sequence structure similar to that found at the S-locus in other species; it also contains sequences similar to elements of a Gypsy-like retrotransposon. The identification of a specific DNA sequence associated with the thrum allele of the Primula S-locus provides the first molecular probe with which to investigate the molecular basis of heteromorphic flower development in Primula.

Base Sequence↗

Primula obconica--is contact allergy on the decline?

Primula obconica, a member of the Primulaceae family, was introduced to Britain from China in 1880. P. obconica cultivars, which are reputed to contain less primin, have been developed over the past number of years in an attempt to reduce the incidence of allergic contact dermatitis. Primin (2-methoxy-6-pentyl-1,4-benzoquinone) is the main sensitizer, although other allergens have been postulated. We believe the incidence of primula allergic contact dermatitis has fallen since the introduction of primin-free P. obconica into the European market and thus the aims of this study were twofold. First, to determine whether the incidence of primula allergic contact dermatitis was truly on the decline and, second, to confirm the presence of primin-free P. obconica in the UK. We surveyed the incidence of primula allergic contact dermatitis in the UK and compared the incidence in the period between 1995 and 2000 with a subsequent follow-up study looking at the incidence for 2002. The results showed a significant fall in primin-positive patch tests from 1995 to 2000. The follow-up results for 2002 showed a further reduction in the number of primin-positive patch tests. The yearly incidence of contact allergy to primin has fallen from 0.785% in 1995/1996 to 0.429% in 2002. This downward trend was statistically significant (P = 0.001). A telephone survey of UK seed suppliers and selected plant retailers was also undertaken to clarify what types of P. obconica were available for sale and to assess suppliers' and retailers' knowledge of the primin-free varieties. This survey showed that 50% of suppliers were selling primin-free varieties but that the majority of surveyed retailers were not currently selling any variety of P. obconica. Our study suggests that although the yearly incidence of contact allergy to primin has fallen significantly over the past 8 years, it is still an important allergen, and thus its inclusion in the standard series remains justified for the foreseeable future.

Allergens↗

Primula dermatitis.

We report the cases of 2 patients diagnosed as having primula dermatitis. Both patients were housewives who had been exposed to primula plants. Although only one related her clinical manifestations with looking after plants, the symptoms of both remitted when contact with primula was avoided. The diagnosis was carried out with a patch test concentration of 0.01% primin pet. As primula dermatitis has variable clinical manifestations that can not easily be related to contact allergy, we emphasize the need to include synthetic primin in our standard patch test series.

Dermatitis, Allergic Contact↗

[Allergic contact dermatitis caused by garlic, Primula, Frullania and Compositae].

As a complementary study to a previous work (14) in which we examined 43 cases of contact dermatitis to plants, we have taken a closer look at the provocative cases which made up 76% of that study - Allium (garlic) (11 cases), Primula (8), Frullania (8) and Compositae (6). The clinical methodology, preparation of extracts and execution of the skin tests were identical to those described in the previous study (14). Patients with sensitivity to Frullania and Compositae were submitted to standard skin tests as shown in table II. These patients were also tested with a 0.1% preparation of Helenin in vaseline. The eleven cases of sensitization to Allium sativum L (garlic) corresponded to women whose primary or secondary profession was that of a housewife. In each case, the reaction was in the form of pulpitis, typically affecting the thumbs, left middle and index fingers and right thumb, which are those that have the greatest contact with the garlic bulb. Primula obconica Hance was responsible for the sensitization of 7 women and 1 man. In two of the patients, the positive test result was unrelated to the clinical picture for which the patients sought medical attention. In one of the two cases, the patient had had prolonged, previous contact with Primula but without reaction. In the other case, the origin of the reaction could not be established. The contact dermatitis produced by Primula are located principally in the face and hands.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzoquinones↗

Biological effects of epicuticular flavonoids from Primula denticulata on human leukemia cells.

The biological effects of epicuticular substances in farinose exudates accumulated on inflorescence shafts and calyces of Primula denticulata on human acute myeloid leukemia cells (HL-60) were analyzed. The crude material possessed little antioxidative capacity but strong cytostatic properties. Some of its known components (5-hydroxyflavone, 2'-hydroxyflavone, 5,2'-dihydroxyflavone, and 5,8-dihydroxyflavone) were further tested to identify the biologically active compounds. The effects of these flavones on cell cycle progression, mitochondrial membrane potential, and reactive oxygen species have been investigated by flow cytometry. The flavonol quercetin was included in the study as reference compound because of its known cytostatic properties and its activity as radical scavenger. Compared to quercetin the flavones induced little apoptosis (up to 40 microM), but despite their low toxicity, the Primula flavonoids possessed strong cytostatic properties even at low concentrations. The cell cycle distribution showed a characteristic time-dependent shift, giving evidence of a generally short-lived effect of the test compounds in the exposed cells. The antioxidative properties quantified according to two different methods correlated with the number of hydroxyl groups. Whereas quercetin strongly affected the mitochondrial membrane potential, none of the Primula flavones showed a comparable effect.

Antioxidants↗

Primula contact dermatitis: an easily overlooked diagnosis.

Contact dermatitis to Primula obconica is not uncommon in the United States, yet it is scarcely mentioned in current North American dermatologic textbooks and literature. Affecting mainly women, primula contact dermatitis is often misdiagnosed since its nondescript pattern suggests an endogenous dermatitis. The author summarizes his experience with nine patients encountered in his practice during two years. Patch testing is important since a positive patch test reaction confirms the diagnosis and helps to convince the patient to discard the offending plant(s). A simple technique of patch testing with the primula leaf is described.

Adult↗

[Primula eczema--well-known and overlooked].

A case of primula dermatitis presenting as recurrent hand eczema is reported. In spite of a positive patch test reaction to primin, the diagnosis was not made until three years later, when the patient was shown a colour photo of Primula obconica and admitted contact with the plant. Since few patients are able to supply correct information of exposure to this primula species, it is recommended to show colour photos of the plant as a routine procedure in cases where there are positive patch test reactions to primin.

Adult↗

Identification of primula fatty acid delta 6-desaturases with n-3 substrate preferences.

Fatty acid Delta(6)-desaturation, the first committed step in C(20) polyunsaturated fatty acid biosynthesis, is generally considered not to discriminate between n-3 and n-6 substrates. We previously identified higher plant species that showed preferential Delta(6)-desaturation of n-3 C(18) fatty acid substrates. A polymerase chain reaction-based approach was used to isolate 'front-end' cytochrome b(5) fusion desaturases from Primula vialii Franchet and Primula farinosa L. Functional analysis in Saccharomyces cerevisiae identified fatty acid Delta(6)-desaturases with a strong specificity for the n-3 substrate alpha-linolenic acid (18:3 Delta(9,12,15)). These results indicate that the accumulation of octadecatetraenoic acid (18:4 Delta(6,9,12,15)) in planta is due to the activity of a novel n-3-specific fatty acid Delta(6)-desaturase.

Amino Acid Sequence↗

Genetic structure of the forest herb Primula elatior in a changing landscape.

To investigate whether changes in land use and associated forest patch turnover affected genetic diversity and structure of the forest herb Primula elatior, historical data on landscape changes were combined with a population genetic analysis using dominant amplified fragment length polymorphism markers. Based on nine topographic maps, landscape history was reconstructed and forest patches were assigned to two age classes: young (less than 35 years) and old (more than 35 years). The level of differentiation among Primula populations in recently established patches was compared with the level of differentiation among populations in older patches. Genetic diversity was independent of population size (P > 0.05). Most genetic variation was present within populations. Within-population diversity levels tended to be higher for populations located in older forests compared with those for populations located in young forests (Hj = 0.297 and 0.285, respectively). Total gene diversity was also higher for old than for young populations (Ht = 0.2987 and 0.2828, respectively). The global fixation index FST averaged over loci was low, but significant. Populations in older patches were significantly more differentiated from each other than were populations in recently established patches and they showed significant isolation by distance. In contrast, no significant correlations between pairwise geographical distance and FST were found for populations in recently established patches. The location of young and old populations in the studied system and altered gene flow because of increased population density and decreased inter-patch distances between extant populations may explain the observed lower genetic differentiation in the younger populations. This study exemplifies the importance of incorporating data on historical landscape changes in population genetic research at the landscape scale.

Age Factors↗