scholarly journals Pollen production in selected species of anemophilous plants

2012 ◽  
Vol 61 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Krystyna Piotrowska

In the study, structural features of flowers of the following allergenic plant species were analysed: <i>Betula verrucosa</i>, <i>Secale cereale</i>, <i>Rumex acetosella</i>, <i>Plantago major</i> and <i>Artemisia vulgaris</i>. Pollen production was established by calculating the number of pollen grains produced by the stamen, flower and inflorescence. The dates of occurrence and pollen grains concentration in the air of Lublin were determined. A positive correlation was found between the length of anthers and the number of pollen grains produced. The largest number of pollen grains per anther is produced by Secale cereale (22 360), whereas the smallest one by Plantago major (5 870). The other species produced intermediate numbers of pollen grains in the anther: <i>Betula verrucosa</i> - 11 160, <i>Rumex acetosella</i> - 10 850, <i>Artemisia vulgaris</i> - 9 580. The birch pollen season in Lublin lasts about a month, and pollen of this taxon reaches the highest airborne concentrations among the studied taxa. Low values of pollen concentrations are characteristic for rye and plantain, whereas slightly higher values are recorded for sorrel pollen. Mugwort pollen reaches high concentrations which are noted at the beginning of August.

2015 ◽  
Vol 68 (4) ◽  
pp. 325-331 ◽  
Author(s):  
Aleksandra Kruczek ◽  
Małgorzata Puc ◽  
Alina Stacewicz ◽  
Tomasz Wolski

The aim of the study was to investigate the concentration of <em>Alnus</em> L., <em>Corylus</em> L. and <em>Betula</em> L. pollen in the village of Gudowo (Western Pomerania, Poland) in the years 2012–2014 in order to estimate the threat of allergenic tree pollen in this rural region. Measurements were performed using the volumetric method (VPPS Lanzoni 2000 pollen sampler). The duration of the pollen season was determined by the 98% method, taking days on which, respectively, 1% and 99% of the annual total pollen grains appeared as the beginning and end of the season. Pollen grains from hazel occurred in the air as the first ones, before pollen grains from alder and birch. The earliest beginning of the hazel pollen season was recorded in 2012, whereas alder and birch pollen seasons started the earliest in 2014. Daily maximum pollen concentrations of the investigated taxa were recorded in 2014. Birch pollen allergens posed the largest threat to pollinosis sufferers. In the years 2012–2014, pollen concentrations equal or higher than threshold values, at which people with pollinosis show allergic symptoms, were recorded most frequently for birch, hazel, and alder (25, 19, and 14 days, respectively). The highest hourly alder pollen concentration was recorded at 16:00 and in the case of hazel at 15:00. The diurnal distribution of birch pollen concentrations does not show any distinct peaks.


Aerobiologia ◽  
2021 ◽  
Author(s):  
Katarzyna Dąbrowska-Zapart ◽  
Tadeusz Niedźwiedź

AbstractThe study's main objective was to specify the extent to which weather conditions were related to the course of birch pollen seasons in the years 1997–2020. The impact of atmospheric conditions on the daily concentrations of birch pollen grains, the Annual pollen integral (APIn), and the length of pollen seasons were studied. The dependency between each meteorological condition and various features of the birch pollen season was determined using Spearman’s rho correlation, the Kruskal–Wallis test, and cluster analysis with the k-means method. It has been shown that the duration of sunshine and average air temperature occurring within 14 days preceding the season has the most significant influence on the beginning of a birch pollen season. The value of daily birch pollen concentrations in Sosnowiec showed a statistically significant positive correlation with the duration of sunlight and the average and maximum wind speed. The daily concentration also depended on the synoptic situation: the mass airflow direction, the type of air mass inflow, and the type of weather front. The near-ground temperature influenced the APIn of birch pollen grains during the period of 14 days before the beginning of the season and the meteorological conditions occurring in the summer of the preceding year such as the maximum temperature, duration of sunlight, the maximum and average wind speed, and the relative air humidity. It was concluded that the length of birch pollen seasons decreased year by year.


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 702
Author(s):  
María Fernández-González ◽  
Estefanía González-Fernández ◽  
Helena Ribeiro ◽  
Ilda Abreu ◽  
F. Javier Rodríguez-Rajo

Natural forests are considered a reservoir of great biological diversity constituting one of the most important ecosystems in Europe. Quercus study is essential to assess ecological conservation of forests, and also of economic importance for different industries. In addition, oak pollen can cause high sensitization rates of respiratory allergies in pollen-allergy sufferers. This study sought to know the pollen production of six oak species in the transitional area between the Eurosiberian and Mediterranean Bioclimatic Regions, and to assess the impact of climate change on airborne oak pollen concentrations. The study was conducted in Ourense (NW Spain) over the 1993–2019 period. A Lanzoni VPPS 2000 volumetric trap monitored airborne pollen. A pollen production study was carried out in ten trees randomly selected in several Quercus forest around the Ourense city. Oak pollen represented around 14% of annual total pollen registered in the atmosphere of Ourense, showing an increasing trend during the last decade. Pollen production of the six studied oak species follow the proportions 1:1:2:5:90:276 for Q. ilex, Q. faginea, Q. rubra, Q. suber, Q. pyrenaica, and Q. robur respectively. We detected a significant trend to the increase of the annual maximum temperature, whereas a decrease of the maximum and mean temperatures during three previous months to oak flowering. This could be related with the detected trend to a delay of the oak Main Pollen Season onset of 0.47 days per year. We also found significant trends to an increase of the annual pollen integral of 7.9% pollen grains per year, and the pollen peak concentration of 7.5% pollen grains per year. Quercus airborne pollen monitoring as well as the knowledge of the reproductive behavior of the main oak species, bring us an important support tool offering a promising bio-indicator to detect ecological variations induced by climate change.


1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.


2013 ◽  
Vol 6 (6) ◽  
pp. 1961-1975 ◽  
Author(s):  
K. Zink ◽  
A. Pauling ◽  
M. W. Rotach ◽  
H. Vogel ◽  
P. Kaufmann ◽  
...  

Abstract. Simulating pollen concentrations with numerical weather prediction (NWP) systems requires a parameterization for pollen emission. We have developed a parameterization that is adaptable for different plant species. Both biological and physical processes of pollen emission are taken into account by parameterizing emission as a two-step process: (1) the release of the pollen from the flowers, and (2) their entrainment into the atmosphere. Key factors influencing emission are temperature, relative humidity, the turbulent kinetic energy and precipitation. We have simulated the birch pollen season of 2012 using the NWP system COSMO-ART (Consortium for Small-scale Modelling – Aerosols and Reactive Trace Gases), both with a parameterization already present in the model and with our new parameterization EMPOL. The statistical results show that the performance of the model can be enhanced by using EMPOL.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcel Polling ◽  
Chen Li ◽  
Lu Cao ◽  
Fons Verbeek ◽  
Letty A. de Weger ◽  
...  

AbstractMonitoring of airborne pollen concentrations provides an important source of information for the globally increasing number of hay fever patients. Airborne pollen is traditionally counted under the microscope, but with the latest developments in image recognition methods, automating this process has become feasible. A challenge that persists, however, is that many pollen grains cannot be distinguished beyond the genus or family level using a microscope. Here, we assess the use of Convolutional Neural Networks (CNNs) to increase taxonomic accuracy for airborne pollen. As a case study we use the nettle family (Urticaceae), which contains two main genera (Urtica and Parietaria) common in European landscapes which pollen cannot be separated by trained specialists. While pollen from Urtica species has very low allergenic relevance, pollen from several species of Parietaria is severely allergenic. We collect pollen from both fresh as well as from herbarium specimens and use these without the often used acetolysis step to train the CNN model. The models show that unacetolyzed Urticaceae pollen grains can be distinguished with > 98% accuracy. We then apply our model on before unseen Urticaceae pollen collected from aerobiological samples and show that the genera can be confidently distinguished, despite the more challenging input images that are often overlain by debris. Our method can also be applied to other pollen families in the future and will thus help to make allergenic pollen monitoring more specific.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yoon Kim ◽  
Sun-Ho Kim ◽  
Dong-Min Shin ◽  
Soo-Hwan Kim

ATBS1-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic-helix-loop-helix (bHLH) transcription factor. Here, we demonstrate that AIF2 negatively modulates brassinosteroid (BR)-induced, BRASSINAZOLE RESISTANT 1 (BZR1)-mediated pollen and seed formation. AIF2-overexpressing Arabidopsis plants (AIF2ox) showed defective pollen grains and seed production while two AIF2 knockout mutants, aif2-1 and aif2-1/aif4-1, displayed opposite phenotypes. Genes encoding BZR1-regulated positive factors of seed size determination (SHB1, IKU1, MINI3) were suppressed in AIF2ox and genes for negative factors (AP2 and ARF2) were enhanced. Surprisingly, BZR1-regulated pollen genes such as SPL, MS1, and TDF1 were aberrantly up-regulated in AIF2ox plants. This stage-independent abnormal expression may lead to a retarded and defective progression of microsporogenesis, producing abnormal tetrad microspores and pollen grains with less-effective pollen tube germination. Auxin plays important roles in proper development of flower and seeds: genes for auxin biosynthesis such as TCPs and YUCCAs as well as for positive auxin signalling such as ARFs were suppressed in AIF2ox flowers. Moreover, lipid biosynthesis- and sucrose transport-related genes were repressed, resulting in impaired starch accumulation. Contrarily, sucrose and BR repressed ectopic accumulation of AIF2, thereby increasing silique length and the number of seeds. Taken together, we propose that AIF2 is negatively involved in pollen development and seed formation, and that sucrose- and BR-induced repression of AIF2 positively promotes pollen production and seed formation in Arabidopsis.


2012 ◽  
Vol 63 (2) ◽  
pp. 97-103
Author(s):  
Małgorzata Malkiewicz ◽  
Kamilla Klaczak

This paper presents the results of an analysis of pollen season patterns for taxa which show the strongest allergenic activity (alder, birch, grasses, and mugwort) in 2008 in the air over Wrocław and Olszanica. The study was carried out using the volumetric method (Burkard trap). The results show variation in pollen seasons between the analyzed localities. An attempt was made to find out in which of the sites in question - the urban site or the rural one - there was a greater risk of allergens of the selected plants. The results of the present study show that the alder, birch and grass pollen seasons in 2008 started and ended earlier in Wrocław, and maximum pollen concentrations were definitely lower. But the mugwort pollen season started earlier and ended much later in Olszanica, while maximum pollen concentration of this taxon was more than twice lower than in Wrocław. In 2008 in the investigated localities, the highest pollen concentrations of the plants in question occurred in the following months: alder in February, birch in April, grasses in June, while mugwort in August. In 2008 alder and birch pollen allergen risk was comparable in the investigated urban and rural environment. However, grass and mugwort pollen allergens posed a significantly greater threat in the rural environment than in Wrocław.


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