Search results for "Pollen"
showing 10 items of 302 documents
Gametic embryogenesis and haploid technology as valuable support to plant breeding
2011
Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced managem…
Paternal effects on functional gender account for cryptic dioecy in a perennial plant.
2004
7 páginas, 3 figuras, 1 tabla.
Cypress pollen: An unexpected major sensitizing agent in different regions of Italy
2014
In this multicenter survey, we assessed the impact of sensitization to cypress in atopic patients in Italy and determined whether cypress pollen concentration changed over time.Allergists were required to collect the results of 100-200 consecutive skin prick tests (SPTs) performed during 2012. Seasonal symptoms were also recorded, as were airborne cypress pollen concentrations (data from the Italian Aerobiology Association) in 1998-2000 and 2010-2012.We examined 2258 atopic outpatients (56% females; age, 2-84 years) sensitized to at least 1 of the aeroallergens tested (Dermatophagoides species, grass, pellitory, olive, cypress, birch, Alternaria tenuis, and dog and cat dander). We found tha…
Randomized placebo-controlled trial comparing fluticasone aqueous nasal spray in mono-therapy, fluticasone plus cetirizine, fluticasone plus monteluk…
2004
BACKGROUND: Corticosteroids are considered to be particularly effective in reducing nasal congestion and are therefore recommended as first-line treatment in allergic rhinitis patients with moderate to severe and/or persistent symptoms. OBJECTIVE: We compared the clinical efficacy of fluticasone propionate aqueous nasal spray (FPANS) 200 microg given once daily, administered in mono-therapy or combined therapy with a H1 receptor antagonist (cetirizine, CTZ) or with a leukotriene antagonist (montelukast, MSK), and the combined therapy of CTZ plus MSK in the treatment of patients affected by allergic rhinitis to Parietaria during natural pollen exposure. In addition, we examined the effect of…
Effect of pollens and preys on various biological parameters of the generalist mite Cydnodromus californicus
2009
The generalist phytoseiid mite Cydnodromus californicus (McGregor) (Mesostigmata Phytoseiidae) is considered a very important biocontrol agent of the spider mite Tetranychus urticae Koch both in greenhouses and field. Its capacity to feed alternative foods allows the increase of the population in field, even when the primary prey is not available. To investigate the effect of various alternative food substances present in the Mediterranean agroecosystems on the biological parameters of C. californicus, laboratory trials were carried out using 17 pollens and 3 preys. As it was expected, T. urticae was the best food for both the postembryonic development and the oviposition rate (100% of atta…
Lack of phosphoserine phosphatase activity alters pollen and tapetum development in Arabidopsis thaliana.
2015
Formation of mature pollen grain, an essential process for the reproduction of higher plants, is affected in lines that are deficient in the enzymes of the phosphorylated pathway of serine biosynthesis (PPSB). Mutants of phosphoserine phosphatase (PSP), the enzyme that catalyses the last step of PPSB, are embryo-lethal. When they are complemented with a construct carrying PSP1 cDNA under the control of the 35S promoter (psp1.1 35S:PSP1), which is poorly expressed in anther tissues, plants display a wild-type phenotype, but are male-sterile. The pollen from the psp1.1 35S:PSP1 lines are shrunken and unviable. Here we report the morphological alterations that appear in the psp1.1 35S:PSP1 lin…
Impact of polyploidy on fertility variation of Mediterranean Arundo L. (Poaceae)
2015
International audience; Failure of seed production in the genus Arundo L. (Poaceae) is often attributed to polyploidy. This study tested the impact of two ploidy levels (2n = 12 and 18x) on the fertility of four Mediterranean Arundo. Viable pollen was screened from its production to its germination, and seed occurrence was monitored in admixture or isolated conditions. In addition, insights on restructuration of polyploid genornes were analysed using molecular cytogenetics. Our results show that high ploidy levels do not automatically induce failure of sexual reproduction. The two ploidy levels are able to produce viable pollen and seed set depending on species and cultural conditions. The …
Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe
2019
Fire is a major disturbance agent in the boreal forest, influencing many current and future ecosystem conditions and services. Surprisingly few studies have attempted to improve the accuracy of fire-event reconstructions even though the estimates of the occurrence of past fires may be biased, influencing the reliability of the models employing those data (e.g. C stock, cycle). This study aimed to demonstrate how three types of fire proxies – fire scars from tree rings, sedimentary charcoal and, for the first time in this context, fungal spores of Neurospora – can be integrated to achieve a better understanding of past fire dynamics. By studying charcoal and Neurospora from sediment cores f…
Towards understanding the abundance of non-pollen palynomorphs : A comparison of fossil algae, algal pigments and sedaDNA from temperate lake sedimen…
2018
Given the increased interest in non-pollen palynomorphs (microscopic objects other than pollen identified from pollen slides) in palaeoecological studies, it is necessary to seek a deeper understanding of the reliability of these results. We combined quantitative information of algal pigments and sedimentary ancient DNA (sedaDNA) of phylotaxonomical resolution to validate the richness and abundance of fossil algae in the sediment of a small temperate lake. For the first time, fossil and sedaDNA algae data were combined in a composite data-set and used to reconstruct algae turnover rates over the last 14,500 years. This comparison serves as both an example of howfossil algae can be used to a…
Bilabiate Flowers: The Ultimate Response to Bees?
2007
† Background and Aims Bilabiate flowers have evolved in many lineages of the angiosperms, thus representing a convincing example of parallel evolution. Similar to keel blossoms, they have obviously evolved in order to protect pollen against pollen-collecting bees. Although many examples are known, a comprehensive survey on floral diversity and functional constraints of bilabiate flowers is lacking. Here, the concept is widened and described as a general pattern. † Methods The present paper is a conceptional review including personal observations of the authors. To form a survey on the diversity of bilabiate blossoms, a search was made for examples across the angiosperms and these were combi…