Search results for "Pollen"
showing 10 items of 302 documents
Comparative investigation of the pollen morphology of Centaurea parlatoris gr. (sect. Dissectae, Compositae) in Sicily
2009
Response to Kruse-Plass et al. (2017) regarding the risk to non-target lepidopteran larvae exposed to pollen from one or more of three Bt maize event…
2017
We respond to the paper of Kruse-Plass et al. (Environ Sci Eur 29:12, 2017), published in this journal, regarding the risk to non-target lepidopteran larvae exposed to pollen from one or more of three Bt maize events (MON810, Bt11 and 1507). We emphasise that what is important for environmental risk assessment is not the number of pollen grains per se, but the degree of exposure of a NT lepidopteran larva to Bt protein contained in maize pollen. The main text of this response deals with general issues which Kruse-Plass et al. have failed to understand; more detailed refutations of each of their claims are given in Additional file 1. Valid environmental risk assessment requires direct measur…
Somatic embryogenesis through in vitro anther culture ofCitrus sinensisL. Osbeck ‘Moro’
2019
In many crops, anther culture is the most used method to induce gametic embryogenesis, aimed to regenerate homozygous plants. However, also somatic embryogenesis can be obtained by this method, when somatic tissue is involved in regeneration process. Many factors can affect this procedure, such as genotype, pre-treatments applied to floral buds, pollen developmental stage, donor plant states, culture media composition and growth culture conditions. Anthers of Citrus sinensis L. Osbeck, cv. Moro, were collected at the vacuolate stage, and after a chilling (4°C) pre-treatment of 7 days, were placed on the same medium, evaluating different temperature stresses applied after the placing in cult…
Survival strategies of the crab spider Thomisus onustus Walckenaer 1806 (Chelicerata, Arachnida, Thomisidae).
1989
The initial energy supply of emerging spiderlings is relatively meagre, so survival without feeding on insects during a spell of bad weather is limited to a period of a few days or weeks. During our investigations, spiderlings of Thomisus onustus (Arachnida, Thomisidae) were kept on different diets. There was a significant difference in survival rate between spiderlings that were starved or fed on pollen, “nectar”, or Drosophila. The results showed that pollen and nectar can be a source of energy for spiders for an extensive period. This demonstrates another way in which spiders may survive starvation when insect prey is lacking and thus ensure the survival of a whole population.
Abundance of cellular material and proteins in the atmosphere.
2005
Suspended atmospheric particles play a crucial role in any global climate scenario: They can both enforce and suppress radiative forcing. In developing climate modeling further, a deeper understanding of atmospheric aerosol is needed. Because of extreme local and temporal variations, proper incorporation of aerosols into models requires modeling of the aerosol itself. It turns out that cellular material and proteins compose up to 25% of the atmospheric aerosol. Consequently, the source strength of the biogenic aerosol in general must be corrected and should be estimated on the order of other major aerosol sources.
The breeding system of Fumana ericifolia: first evidence of autogamy in woody Cistaceae
2001
Fumana ericifolia belongs to the family Cistaceae, in which all perennial species previously studied have been reported to be self-incompatible and xenogamous. Here we show that F. ericifolia is self-compatible and autogamous. Its flowers last only four to eight hours and produce a small amount of pollen and ovules. Self-pollination depends on changes in the relative position of the stigma and the anthers, triggered by the abscission of the petals; this in turn causes closing of the sepals, which push the anthers onto the stigma. Pollen remains highly viable and germinable, and the stigma keeps its receptivity several hours after the loss of the petals. Hand pollination treatments revealed …
Preliminary Results on the Effect of Magnetic Fields on Anther Culture and Pollen Germination of Citrus clementina Hort. ex Tan.
2003
Exposure to electromagnetic fields seems to modify the biological behaviour of seeds, roots, pollen grains and buds of several plants. This procedure has been also suggested as a tool to improve the utilization of plant species (Firetto et al., 2000, 2001, Petruszewski S., 1996). Since the first haploid embryogenic calli production and plantlet regeneration by anther culture of C. clementina Hort. ex Tan. 'Nules' was reported (Germany et al., 1994), several studies have been carried out to improve both the frequency of microspore embryogenesis and the percentage of plantlet regeneration. To enlarge the number of respondent genotypes and to improve the induction rate (the frequency of pollen…
Safety of sublingual immunotherapy started during the pollen season
2009
Sublingual immunotherapy (SLIT) is safer than subcutaneous immunotherapy (SCIT) and this has lead to the reconsideration of the use of ultra-rush schedules for SLIT. The aim of this study was to assess the safety of ultra-rush SLIT in pollen-allergic children according to different timing of administration in relation to the pollen season.In total, 34 children with pollen-induced rhinitis and 36 with pollen-induced asthma and rhinitis, were enrolled and assigned to three study groups: group 1 (n = 17 patients): conventional pre-seasonal-SLIT treatment; group 2 (n = 23 patients), seasonal SLIT ended before the pollen seasonal peak; group 3 (n = 30 patients), SLIT began after the pollen seaso…
Efficacy but not effectiveness of sublingual immunotherapy for grass pollen allergy: Time to avoid waste in health-care expenditure
2015
Influence of Microspore Development on Pollen Protoplast Isolation in Digitalis obscura
1991
Summary Protocols for the enzymatic isolation of Digitalis obscura pollen protoplasts are described. The developmental stage of the microspores was a critical factor for successful isolation since protoplasts were obtained only from tetrads. The highest yield of viable protoplasts was achieved with an enzymatic mixture containing helicase, cellulase and pectolyase in 0.5 M sucrose. In different culture techniques employed, cell wall regeneration took place only when protoplasts were plated in agarose drops.