摘要:

Herbarium pollen from four Acanthaceae species with caveate exines was rehydrated using a solution of tannic acid and glutaraldehyde (TAG), followed by fixation with osmium tetroxide. The results demonstrate the presence of lipoidal material contained in the caveae and columellar interstices. The nature, synthesis and possible function of this material are discussed. Aspects of endexine ultrastructure and deposition are also discussed.

ISSN:0017-3134    

DOI:10.1080/00173139509429027

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The 13 species ofAesculusrecognized in a revision by Hardin (1957, 1960) and two species ofBilliawere investigated by LM and SEM, and three species ofAesculusby TEM. In addition to the species recognized by Hardin four more species ofAesculus (A. bushii, A. megaphylla, A. rupicolaandA. polyneura) can be distinguished on the basis of their pollen characteristics. Four pollen groups ofAesculusspecies are described. The data of Hsiech (1979) on the polymorphism of the sect.Calothyrsuswere confirmed. In addition to a few pollen features which are discrete one, a continuum or more complicated regular varieties was observed with respect to many pollen characteristics. These patterns are not reflected in any typology or classification and are usually ignored in systematic investigations, and consequently also in the evolutional interpretation of the morphological data. This investigation of the regular pattern in the variety of pollen aperture arrangement allows an assumption about the mechanisms of pollen aperture determination and the origin of variety.

ISSN:0017-3134    

DOI:10.1080/00173139509429028

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The exomorphology of pollen grains of all North American species ofCoreopsishave been thoroughly studied under the SEM for the first time with a view to contributing data to the ongoing studies on generic delimitation betweenBidensandCoreopsis. The grains are echinate, tricolporate, isopolar, radially symmetrical, and spheroidal. The size of the pollen grain is between 16.3–31.7 ± 15.5–28.3 μm and the length of the spine ranges between 3.5 and 6.8 μm. No distinct differences in pollen morphological features between the sections of North AmericanCoreopsiswere found. These results are also compared with previous findings on the pollen grains of AfricanBidens(incl.Coreopsis) and only few quantitative and qualitative differences in exomorphology were detected.

ISSN:0017-3134    

DOI:10.1080/00173139509429029

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The pollen morphological structures of Turkish endemic species ofCentaurea armenaBoiss.,C. aucheranaD. C.,C. pyrrhoblepharaBoiss.,C. fenzliiReichardt.,C. hermanniiF. Hermann.,C. kilaeaBoiss.,C. kurdicaReichardt.,C. tchihatcheffiiFisch & Mey. have been studied in detail by means of light (LM) and transmission (TEM) microscopes for the first time. LM examinations show that the pollen grains of eight taxa are more or less spheroidal — subprolate, tricolporate, tectate — perforate, microechinate — scabrate, amb triangular and theJacea-iype is dominant. On the basis of their exine ultrastructureC. pyrrhoblephara, C. tchihatcheffiiandC. aucheranaseem to resemble the Anthermoid-type, but the other five taxa resemble the Helianthoid-type.

ISSN:0017-3134    

DOI:10.1080/00173139509429030

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The settling velocity in still air of natural and dyed spores and pollen of several species was measured using the method of McCubbin and was found to be as follows (in cm s-1): black spruce (Picea mariana), 3.19; jack pine (Pinus banksiana), 2.53;Lycopodium, 2.31; dyedLycopodium, 2.15; oil palm (Elaeis guineensis), 3.00; dyed oil palm, 2.16 and corn(Zea Mays), 30.95. The percentage of clustered spores and pollen was taken into account but was not found to significantly affect settling velocity except in the case of dyed oil palm. Comparisons of the measured settling velocities of clustred grains were made with the model of Ferrandino and Aylor. This was found to be accurate in general, but tended to over-estimate the settling velocity of clumped spores ofLycopodiumand of dyed pollen of oil palm.

ISSN:0017-3134    

DOI:10.1080/00173139509429031

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The existence of small particles emitted from the dehiscing anther at the time of pollen shedding is shown. We examined pollen samples of five plants causing pollinosis in Japan:Cryptomeria japonica, Alnus japonica, Quercus serrata, Dactylis glomerataandAmbrosia elatior. The pollen samples ofC. japonicacollected by hydroponic culture had two kinds of particles. The size of these particles was 0.46 to 1.4 μm and 29 to 40 μm (pollen grains) in diameter. The number of the small particles was about 8-fold greater than that of intact pollen grains.Alnus japonica, Quercus serrataandDactylis glomerataalso discharge small particles other than pollen grains although the number is not so large asCryptomeria japonica. We could not recognize any small particles in a pollen sample ofAmbrosia elatior.

ISSN:0017-3134    

DOI:10.1080/00173139509429032

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Long term observations of atmospheric pollen offer the possibility of studying patterns in fluctuations in the airborne pollen presence. In this study, birch pollen measured at five monitoring stations in Europe with records of 18 to 30 years, have been analysed comparatively on three aspects: trends and fluctuations of annual sums of daily concentrations, and starting dates of airborne presence. The results show weakly rising trends at all five stations. The observed fluctuations in airborne birch pollen quantities are suggestive of synchronous, alternatingly cyclic rhythms, beit with a-synchronous aberrant years and phase shifts. For the starting dates of the birch pollen season the air temperature during the preceding 4 decades-of-days are of decisive importance.

ISSN:0017-3134    

DOI:10.1080/00173139509429033

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Both the seasonal and diurnal incidence of grass pollen in the atmosphere of Melbourne have been established using data from seven pollen seasons (1975–1980 and 1991–1993). Grass pollen represented an average of 26% (ranging from 22 to 33.1%) of the total pollen count. November and December are the most important months with an average of 81% of the total grass pollen. There is marked variation in the total seasonal and daily grass pollen counts. The total seasonal grass pollen count varied from 2319 to 6798 grains, while the daily grass pollen count fluctuated from 0 to 549 grains m-3of air. In this study, we arbitrarily assigned days during the grass pollen season with > 100 grains m-3of air as extremely high, > 50 grains m-3of air as high, 21–50 grains m-3of air as moderate and < 20 grains m-3of air as low. The number of days with extremely high counts varied from 3 to 26. The number of days with high counts varied from 7 to 21, with the highest number of days occurring in seasons with more than 5500 grass pollen. This classification has been used in the dissemination of pollen counts to the media in order to provide information for allergy suffers.

ISSN:0017-3134    

DOI:10.1080/00173139509429034

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The hypothesis that gene flow northwards by long distance wind dispersal of pollen is a contributing factor in Scots pine (Pinus sylvestrisL.) seed crops in northern Scandinavia (Umeå) was examined. Pollen was observed in the air before local pollen shedding began. This pollen has been shown to germinate and is likely to be viable. This early pollen was probably not of local origin. Wind patterns and the geographic pattern of pollen shedding were such that it is likely that the origin of the early pollen was hundreds of km to the south. Since many of the female strobili are receptive to pollination before local pollen shedding occurred, early non-local pollen has an advantage over later local pollen. Thus, the gene flow caused by pollen migration is likely to be large enough to be of evolutionary significance.

ISSN:0017-3134    

DOI:10.1080/00173139509429035

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

As part of a national programme on the role of inhalant allergens in respiratory allergic disorders particularly bronchial asthma in the Kingdom of Saudi Arabia, a qualitative, volumetric and immunological study of outdoor aeroallergens was conducted. Among various pollen grains and fungal spores identified,Ulocladiumspp. emerged to be one of the major spore categories in the outdoor air spora.Ulocladiumdata using Burkard volumetric sampler from three different sites for 12 months each and for 3 continuous years from one site are presented. In addition, data for 12 months for two other sites in Riyadh City using personal volumetric sampler are also presented. The peak mean weekly concentration ofUlocladiumwas highest in the populated coastal (Jeddah) with > 120 spores m-3of air. The data displayed a trend at all sites in seasonal variations showing winter with higher concentration and summer with lower concentration. The maximum concentrations for all sites fluctuated and remained under 300 spores m-3except for Jeddah reaching over 1200 m-3in late winter. The percentage ofUlocladiumin the air also varied at all sites with highest composition being 7% of the total air spora using Burkard trap and 6% using personal volumetric sampler. However, at all sitesUlocladiumwas found to be among the most frequently encountered genera. Extracts ofUlocladiumwere prepared from local isolates and tested on 100 allergic patients attending allergy clinic at investigators hospital. 13% positive SPT result with various fungal extracts including 5% byUlocladiumwere recorded in these patients. The study suggets a possible role ofUlocladiumas an allergen in the region and necessitates further investigation of the genus by inclusion ofUlocladiumantigens in allin vivoandin vitroallergy diagnostic tests in the Kingdom.

ISSN:0017-3134    

DOI:10.1080/00173139509429036

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor