A preliminary survey of airborne pollen in Madras City

The atmospheric pollen of Madras city was surveyed during a 1-year period (January–December 1995) with a vertical cylinder trap. A total of 32 pollen types were identified, among which nine were present throughout the year. These belonged to Poaceae,Casuarina equisetifolia Foster and Foster f.,Prosopis juliflora (SW.) DC.,Acalypha indica L.,Parthenium hysterophorus L., Cyperaceae,Cocos nucifera L., Amaranthaceae, andTypha angustata Borry and Chaub. Among the identified pollen, 61.05% belonged to trees, 21.01% to grasses, 11.65% to herbs and 6.27% to shrubs. Anemophilous pollen contributed about 52.87% to the total while entomophilous and amphiphilous pollen contributed 38.89 and 8.22%, respectively. Pollen belonging to Poaceae were found to be most predominant in the air of Madras city followed byCasuarina equisetifolia andProsopis juliflora.     

Effects of pollen competitive environment on pollen performance in Mirabilis jalapa (Nyctaginaceae)

 We examined the influence of pollen competitive environment on pollen performance in Mirabilis jalapa. We used the number of pollen grains and the number of pollen tubes per pistil as measures of pollen competition. Pollen germination, pollen tube penetration into the style, and pollen tube growth rates were used as measures of pollen performance. All three measures of pollen performance were affected by the competitive environment. Pollen germination was greatest at intermediate pollen load sizes. The percentage of germinated pollen grains that penetrated the stigma and grew into the style decreased with pollen load size. Pollen tube growth rate in the style was greater and more variable with larger numbers of pollen tubes in the style. Controlling for the degree of selection at the stigma indicated that pollen-pollen or pollen-style interactions were the likely causes of increased growth rates. Received: 28 October 1996 / Revision accepted: 24 January 1997     

Evaluation of indoor passive pollen sedimentation over 1 year: a possible source of contamination?

The study aimed to evaluate the possible contamination by passive indoor pollen sedimentation in a laboratory where routine pollen analyses were conducted, but where no particular laboratory policies were adopted to limit contamination. Gravimetric pollen deposition was observed on traps (petri dishes soaked with glycerol) set in the palynology laboratory, under an extractor hood and on the bench beside it over 1 year (1995–1996), and in an air filtered room in a flow cabinet and on its roof over 1 month for comparison. Under the extractor hood, three types of airborne particles were deposited: pollen grains, spores and algae, representing 32.35, 67.28 and 0.37%, respectively, of the total sedimented particles over 1 year. The number of pollen grains deposited on the surface trap ranged from 0 (27 November to 4 December 1995) to 707 (10–18 April 1995). The highest number of taxa during a weekly collection was 23 (9–15 May 1995). The pollen flora represented by anemophilous pollen (>90% of the trapped pollen) was related to the vegetation next to the laboratory:Acer, Carpinus, Castanea, Corylus, Cupressaceae, Pinus, Quercus, Salix, Taxus for trees and shrubs andArtemisia, Brassicaceae, Plantago, Poaceae, andUrticaceae for grasses and weeds. Indoor pollen deposition corresponded to the period of the outdoor pollination (macroscopic field observation) which lasted from March to the beginning of August. However, some pollen were almost always present in the collection (Poaceae, Salix, Castanea, Betula), reflecting the occurrence of pollen grains in the atmosphere out of the pollination period. Moreover, about five times more entomophilous pollen was found under the extractor hood compared to the other area of the laboratory; even in the flow cabinet of the air filtered room, 237 particles were captured (versus only 15 on the roof). These data suggest a possible human contamination during operations under the extractor hood or in the flow cabinet. Although few airborne pollen were found, possible contamination has to be considered in investigations where even low pollen quantities are of interest.     

Airborne pollen calendar of the central region of Bursa (Turkey)

This report describes qualitatively and quantitatively the level of pollen in the atmosphere in the central region of Bursa. Turkey. In 1991, the season of maximum pollen concentration was from April to June, with a prevalence of arboreal pollen during the initial months, and of pollen from herbaceous plants in the latter months. During the year of research, 24 taxa of arboreal and 12 taxa of herbaceous pollen grains were collected and identified. In the region investigatedPinus, Cupressaceae/Taxaceae,Abies nordmanniana, Platanus orientalis, Olea europaea, Gramineae, Urticaceae, Chenopodiaceae/Amaranthaceae,Artemisia and Compositae were responsible for the greatest amounts of pollen. Some important allergenic pollens such asOlea europaea, Gramineae and Urticaceae were also found in high concentration. In this study, a pollen calendar for the region is presented.     

Vegetation changes and human occupation in the Patagonian steppe, Argentina, during the late Holocene

Vegetation changes during the late Holocene are interpreted from four fossil pollen sequences from two caves at the Los Toldos archaeological locality, Santa Cruz province, Argentina. Taphonomic processes are particularly taken into account in order to analyze the effects on the fossil pollen records of biotic factors such as human occupation and animals, and abiotic ones such as volcanic ash fall. Fossil pollen assemblages are interpreted using local modern pollen data. The main vegetation change occurred at ca. 3750 uncal b.p., when a shrub steppe of Asteraceae subf. Asteroideae with Schinus, Ephedra frustillata and a high proportion of grasses was replaced by a shrub steppe of Colliguaja integerrima and Asteraceae subf. Asteroideae. This change is synchronous with an archaeological record change and could be related either to moderate climatic variations or the effects of ash fall on the environment. Plant communities similar to the present-day ones were established in the Los Toldos area from ca. 3750 uncal b.p.     

胀果甘草花粉生活力测定及甘草的杂交育种

杂交育种是最为传统的选育新品种的方式之一,花粉生活力能够影响其中遗传物质的传递。胀果甘草是3种药典收录的甘草之一,具有许多特殊活性成分。通过TTC法和离体萌发法对2个胀果甘草(Glycyrrhiza inflata)种质资源GJJ-7和GJJ-9花朵开放5个时期(a~e)的花粉生活力进行测定。结果表明,GJJ-7花粉生活力趋势在5个时期呈现波浪型,在a、d时期达到最高;GJJ-9花粉生活力会随着花瓣展开度的变大而升高,在e时期达到最高。离体萌发结果表明GJJ-7和GJJ-9花粉生活力随花朵开放程度增大呈先升高后降低的趋势,萌发力均在c时期最高。杂交结荚率则与离体萌发结果一致,说明离体萌发法测定花粉生活力比TTC法更可靠。以光果甘草(G.glabra) S-7和S-12为母本的杂交组合结荚率低,但能够获得发芽率高的种子;以乌拉尔甘草(G.uralensis) GDN-16为母本的杂交组合结荚率高,但种子发芽率低,说明在甘草杂交中父母本的选择对结荚率有重要影响。     

Transport of airborne pollen into the city of Thessaloniki: the effects of wind direction, speed and persistence

We examined the effect of the wind vector analyzed into its three components (direction, speed and persistence), on the circulation of pollen from different plant taxa prominent in the Thessaloniki area for a 4-year period (1996–1999). These plant taxa were Ambrosia spp., Artemisia spp., Chenopodiaceae, Corylus spp., Cupressaceae, Olea europaea, Pinaceae, Platanus spp., Poaceae, Populus spp., Quercus spp., and Urticaceae. Airborne pollen of Cupressaceae, Urticaceae, Quercus spp. and O. europaea make up approximately 70% of the total average annual pollen counts. The set of data that we worked with represented days without precipitation and time intervals during which winds blew from the same direction for at least 4 consecutive hours. We did this in order to study the effect of the different wind components independently of precipitation, and to avoid secondary effects produced by pollen resuspension phenomena. Factorial regression analysis among the summed bi-hourly pollen counts for each taxon and the values of wind speed and persistence per wind direction gave significant results in 22 cases (combinations of plant taxa and wind directions). The pollen concentrations of all taxa correlated significantly with at least one of the three wind components. In seven out of the 22 taxon-wind direction combinations, the pollen counts correlated positively with wind persistence, whereas this was the case for only two of the taxon-wind speed combinations. In seven cases, pollen counts correlated with the interaction effect of wind speed and persistence. This shows the importance of wind persistence in pollen transport, particularly when weak winds prevail for a considerable part of the year, as is the case for Thessaloniki. Medium/long-distance pollen transport was evidenced for Olea (NW, SW directions), Corylus (NW, SW), Poaceae (SW) and Populus (NW).     

Stimulation of pollen tube growthin vitro by dicarboxylic acids

Summary Effect of eight dicarboxylic acids and three monocarboxylic acids on pollen growth ofCamellia japonica was tested. While monocarboxylic acids inhibited pollen germination and pollen tube elongation, dicarboxylic acids, namely oxalic, succinic, suberic, adipic, sebacic, traumatic cis-1,2-cyclohexane dicarboxylic, and 3,3-diethyl glutaric acids stimulated pollen tube elongation stronger than indoleacetic acid.     

A national survey of airborne pollen and grass flowering in New Zealand,with implications for respiratory disorder

Airborne pollen and spore levels were monitored at seven sites in New Zealand using the Intermittent Cycling Rotorod sampler during the summer of 1988/1989. Grasses formed the major component of atmospheric pollen levels during spring and summer at every locality. Peak levels of grass and total pollen occurred during December or late November, with a slight latitudinal lag apparent at the more southern sites. Highest levels were recorded at the smaller rural centres of Gore and Kaikohe and the lowest at the larger urban centres of Auckland, Christchurch and Wellington. We make a first approximation of the likely risk to hayfever and allergic asthma patients at each of the seven centres. For example, significantly higher grass pollen levels were experienced at Kaikohe on 44% and 65% of days during November and December, compared with just 15% and 8% at Auckland. By recording the flowering seasons of the principal allergenic grass species at each locality, we determined the potentially allergenic grasses contributing to peak pollen levels, the most ubiquitous being tall fescue (Festuca arundinacea Schreb.), ryegrass (Lolium perenne L.,L. multiflorum Lam.), cocksfoot (Dactylis glomerata L.), Yorkshire fog (Holcus lanatus L.) and sweet vernal (Anthoxanthum odoratum L.). Corresponding author. Deceased.     

Identification and characterization of PiORP1, a Petunia oxysterol-binding-protein related protein involved in receptor-kinase mediated signaling in pollen, and analysis of the ORP gene family in Arabidopsis

Oxysterol-binding proteins (OSBPs) and oxysterol-binding-protein related proteins (ORPs) are encoded by most eukaryotic genomes examined to date; however, they have not yet been characterized in plants. Here we report the identification and characterization of PiORP1, an ORP of Petunia inflata that interacts with the cytoplasmic kinase domain of a receptor-like kinase, named PRK1, of P. inflata. PiORP1 is phosphorylated by PRK1 in vitro and therefore may be involved in PRK1 signaling during pollen development and growth. RNA gel blot analysis showed that PiORP1 and PRK1 had very similar expression patterns in developing pollen, mature pollen and pollen tubes. GFP fusion proteins of PiORP1 localized in the plasma membrane of pollen tubes at distinct foci and its PH domain alone was sufficient to mediate this localization. The sequence for the oxysterol-binding domain of PiORP1 was used to search the genome of Arabidopsis; 12 ORPs were identified and phylogenetic analysis revealed that they fell into two distinct clades, consistent with the ORPs of other eukaryotes. RT-PCR analysis showed that all 12 Arabidopsis ORPs were expressed; 10 were expressed in most of the tissues examined under normal growth conditions, but only three were expressed in pollen. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users. GenBank accession number for PiORP1: DQ241801     

Seasonal distribution of pollen in the atmosphere of melbourne: an airborne pollen calendar

Environmental monitoring of pollen grains in the atmosphere of Melbourne has been achieved using Burkard volumetric traps. Twenty-two families of flowering plants and confiers were identified in the pollen counts. About 62% of these pollen grains belonged to trees, 20% to grasses and 9% to herbs and weedy plants. During spring and summer, the atmosphere contained about 70% of the total annual pollen count. Tree pollen, predominantly elm and cypress, occurred abundantly in late winter and spring, with grass pollen predominantly in spring and early summer. These three types of pollen grains occurred in significant amounts, together accounting for more than 60% of the total annual catch. A seasonal incidence chart (pollen calendar) for Melbourne based on 2 years observation has been constructed. This pollen calendar is useful in identifying sources of allergies against particular seasonal airborne pollen types. Comparison of the time of occurrence of a particular pollen type using the pollen calendar and the time of allergic symptoms, can lead to accurate diagnosis and preventive measures being taken. This study has confirmed that grass pollen is the major source of allergenic pollen in the external environment triggering hay fever and allergic asthma in spring and early summer in Melbourne, Australia.     

Monitoring of pollen rain in moss polsters and mats in view of their suitability as controls for determining the air-borne component of pollen spectra in herbivore faeces

Pollen has been extracted from six bryophyte and two lichen taxa, sampled from three habitats: upland heath, lowland bog and mixed woodland, in both west and east Scotland. The highest number of pollen taxa was recorded in bothSphagnum andThuidium; the lowest numbers of pollen taxa were recorded in two of the mosses and both lichens. For pollen rain control purposes in herbivore faecal studies, woodland species of bryophytes are not suitable due to the sheltering effects from rain provided by the overhead canopy. Open habitats such as moorland heath and bog provide polsters/mats which normally trap pollen rain more effectively for control purposes. The aim of this study was twofold: to observe the effectiveness of selected polsters and lichens as traps for pollen rain and to establish eventually, whether or not such vegetative traps could be used as controls in pollen spectra analyses of herbivore faeces for the determination of nutritional regime and habitat. From a comparison with recent studies in north west Spain of three taxa in common with Scottish samples,Polytrichum demonstrated a consistently higher number of pollen taxa trapped.Thuidium andCladonia all yielded between one and a half and three times the number of pollen taxa as in the same three bryophyte/lichen taxa sampled in Scotland. Investigation relating the pollen rain trapped in polsters to that in faecal material are continuing, and will be reported in due course.This paper is based on one given by E.C. at the 5th International Aerobiology Conference, held at Bangalore, India, August 1994.     

Monitoring of pollen rain in moss polsters and mats in view of their suitability as controls for determining the air-borne component of pollen spectra in herbivore faeces

Pollen has been extracted from six bryophyte and two lichen taxa, sampled from three habitats: upland heath, lowland bog and mixed woodland, in both west and east Scotland. The highest number of pollen taxa was recorded in bothSphagnum andThuidium; the lowest numbers of pollen taxa were recorded in two of the mosses and both lichens. For pollen rain control purposes in herbivore faecal studies, woodland species of bryophytes are not suitable due to the sheltering effects from rain provided by the overhead canopy. Open habitats such as moorland heath and bog provide polsters/mats which normally trap pollen rain more effectively for control purposes. The aim of this study was twofold: to observe the effectiveness of selected polsters and lichens as traps for pollen rain and to establish eventually, whether or not such vegetative traps could be used as controls in pollen spectra analyses of herbivore faeces for the determination of nutritional regime and habitat. From a comparison with recent studies in north west Spain of three taxa in common with Scottish samples,Polytrichum demonstrated a consistently higher number of pollen taxa trapped.Thuidium andCladonia all yielded between one and a half and three times the number of pollen taxa as in the same three bryophyte/lichen taxa sampled in Scotland. Investigation relating the pollen rain trapped in polsters to that in faecal material are continuing, and will be reported in due course. This paper is based on one given by E.C. at the 5th International Aerobiology Conference, held at Bangalore, India, August 1994.     

Pollen size evolution: correlation between pollen volume and pistil length in Asteraceae

Based on the assumptions that pollen tube length is predetermined by provisions in the pollen and that it is a function of pistil length, I hypothesise that species with longer pistils will have larger pollen grains than species with shorter pistils, and that pistil length and pollen size will be positively correlated in a linear manner. To test this hypothesis, the relationship between pollen grain volume and pistil length was compared in 43 Asteraceae species from Argentina. A positive linear correlation was found between pollen volume and pistil length. This correlation remained significant even after potential effects of phylogenetic relatedness were removed. The maintenance of this correlation suggests that in Asteraceae the association between pistil length and pollen volume may reflect a functional rather than a phyletic relationship. In addition, the pistil length: pollen volume ratio (PPR) was analysed in relation to the phylogenetic position of the species. High values of PPR would imply a reduction of the male gametophyte in relation to the minimal volume that a pollen grain must have to grow and fertilise an ovule. Thus, the general pattern of pollen volume reduction in relation to pistil length previously found among many angiosperm families will be also present within a family, i.e., PPR values of derived Asteraceae would be higher than those of basal species. Results indicated that reduction of pollen volume in derived Asteraceae was three times greater than the concomitant shortening of pistil length. Consequently, PPR increased with the phylogenetic position of the taxa. This work supports the correlation between pistil and pollen characters previously found for other plant families and confirms the influence of post-pollination processes on pollen size evolution. Received: 4 November 1999 / Revision accepted: 14 February 2000     

Effects of pollen-synthesized green fluorescent protein on pollen grain fitness

Genetically engineered pollen with a visible marker gene could be useful to monitor the movement of transgenic pollen provided there are no negative physiological or fitness effects of expressing such a gene. In this study, we measured the fitness of Nicotiana tabacum cv. Xanthi pollen expressing the marker gene green fluorescent protein (GFP). Average pollen tube germination frequencies and pollen tube growth rates in vitro were measured in three different types of plants: (1) plants producing GFP in pollen cells only (LAT59-GFP), (2) plants synthesizing GFP under the control of a constitutive promoter (CaMV 35S) in which no GFP was produced in pollen, and (3) non-transgenic plants. Pollen synthesizing the GFP protein did not differ significantly in average pollen germination frequencies from pollen without GFP (P=0.65). Average pollen tube growth rates over a 5-h period did not differ significantly between transgenic and non-transgenic types (R²=0.89, 0.98, and 0.95, respectively, for GFP-tagged, 35S-GFP, and wild type). Overall, GFP expression in pollen grains of tobacco was not found to have an effect on pollen fitness under the controlled experimental conditions of this study.     

Influence of the pH of the stigmatic exudate on male-female interaction in Rosa hybrida L

Summary The in vitro germination of rose pollen is influenced by the pH of the medium. Both germination percentage and length of emitted pollen tubes were maximal for in vitro germination and tube elongation at pH 5 and minimal at pH 3 and 9 (Rosa hybrida L. var P 30 pollen). Three varieties characterized by having a stigmatic exudate of pH = 5 and another three varieties having one of pH = 9 were pollinated with the same pollen. Pollination effectiveness, as indicated by hip set (number of hips/pollmated flowers × 100) and mean number of achenes per hip, were significantly different: it was much higher for the varieties with the stigmatic exudate of pH = 5. pH control on pollination efficiency and subsequent fecundation success is proposed and discussed.     

Airborne pollen of Betula,Corylus and Alnus in Zagreb,Croatia. A three‐year record

The aim of this study was to construct a picture of the influence of meteorological conditions on the start and duration of the airborne Betulaceae pollen season and the pollen concentrations in the atmosphere of Zagreb, Croatia. The study during three seasons (2002–2004) used a 7‐day Hirst‐type volumetric pollen and spore trap. Total annual airborne pollen of Alnus, Corylus and Betula greatly varied from year to year. The differences in the dates of onset of airborne pollen presence of Alnus, Corylus and Betula noted in Zagreb in 2002–2004 were controlled by weather conditions, particularly temperature and precipitation. In all years studied, airborne pollen peaks were recorded on days with temperature above 0°C and without or minimal precipitation. The mean number of days with airborne pollen concentrations exceeding levels which provoke symptoms of an allergic reaction was 15, 16 and 29 days for alder, hazel and birch, respectively. The results of the present study may provide useful data for allergologists to reach accurate diagnoses, and timely information on concentrations of airborne pollen types and concentrations for individuals with pollen hypersensitivity.     

Pollen proteins after two-dimensional gel electrophoresis and pollen morphology of the amphiploids Aegilops kotschyi and Ae. variabilis with Secale cereale

Proteins from pollen of parent forms and amphiploids Aegilops variabilis ×Secale cereale and Ae. kotschyi×S. cereale, obtained by in vitro propagation or colchicine treatment of F₁ hybrids, were subjected to a study by two-dimensional (2-D) electrophoresis. Qualitative and quantitative diversities of protein patterns were revealed for the amphiploid pollen. The majority of peptides found in the parent forms were also present in the patterns of the amphiploid pollen; however, some of the parent-form-peptides were not expressed and proteins characteristic only of the amphiploids appeared. In the 2-D combined protein pattern obtained for the parent forms, amphiploids Ae. variabilis × S. cereale produced pollen with a poorer spectrum of proteins. In amphiploid 408B, obtained from treated the F₁ generation with colchicine, the 2-D pattern revealed the presence of less than 50% of the proteins recorded for the parent forms. Pollen grain morphology was studied under a scanning microscope. The structure and shape of exines differed from those of the parents. In the parent forms the pollen grains had only one pore, while in amphiploid pollen, one, two or three pores were observed. Possible explanations for the differences in the 2-D patterns of amphiploids and their parent forms (impoverishment of the protein spectrum and appearance of new peptides) are (1) somaclonal variation and mutagenic activity of colchicine, (2) suppression of structural genes, (3) activity of regulators and (4) translocations. Pollen grains with two or even three pores could appear as a result of the independent activity of the genes from three amphiploidal genomes. Received: 6 March 2001 / Accepted: 26 June 2001     

CONSUMER DRIVEN POLLEN LIMITATION OF SEED PRODUCTION IN MARSH GRASSES

While flower predators can limit the sexual expression and seed production of salt marsh grasses, the relationship between these two effects of consumers has not been explored. At our study site, predation on Spartina patens, Spartina alterniflora, and Distichlis spicata was twice as high in 1985 (~70% ovule destruction) as in 1986 (~35% ovule destruction). In both years consumers destroyed flowers before maturity, reducing sexual expression, and particularly suppressed male sexual expression. Sexual suppression of males was much more pronounced in 1985 when flower predation was severe and the seed production of undamaged ovules was dramatically reduced. A number of lines of evidence suggest that predator limitation of male sexual expression and pollen supply contributed to low seed output in 1985. 1) Undamaged ovules of all three grasses protected from consumers but exposed to ambient windbome pollen set many more seeds in 1986 than in 1985, suggesting that pollen was more abundant in 1986; 2) Artificial pollinations revealed that marsh grasses are generally pollen-limited and that pollen limitation at our study site was more severe in 1985 than 1986; and 3) Caging stands of marsh grasses generally led to less predator damage, increased male densities and seed sets similar to those for hand-pollinated flowers. Our results support the hypothesis that flower predators can indirectly limit seed production by decreasing pollen availability.     

Uptake and metabolism of flavonols during in-vitro germination of Petunia hybrida (L.) pollen

Flavonol-deficient petunia pollen [conditionally male fertile (CMF) pollen] is unable to germinate but application of nanomolar concentrations of flavonol aglycones completely restores function (Mo et al. 1992). In this study a chemically synthesized radioactive flavonol, [4′-O-¹⁴C]kaempferide, was used as a model compound to study the metabolism of flavonols during the first few hours of pollen germination. [4′-O-¹⁴C] Kaempferide was as efficient at inducing CMF pollen germination as kaempferol and quercetin, the aglycone form of the endogenous flavonols in petunia pollen. Analysis by high-performance liquid chromatography (HPLC) of extracts from both in-vitro-germinated pollen and the germination medium showed that more than 95% of the applied radioactivity was recovered as three kaempferide 3-O-glycosides and unmetabolized kaempferide; no flavonol catabolites were detected. Only HPLC fractions that contained the aglycone, or produced it upon acid hydrolysis, could induce CMF pollen germination in vitro. Structurally diverse flavonols could be classified according to how efficiently the aglycone was internalized and glycosylated during pollen germination. The ability of an individual flavonol to restore germination correlated with the total uptake of flavonols but not with the amount of glycoside formed in the pollen. Thus this study reinforces the conclusion that flavonol aglycones are the active compound for inducing pollen germination. Received: 4 November 1996/Accepted: 4 December 1996