摘要:

Pollen representing twenty-three species in all eleven genera of Styracaceae was examined by combined light, scanning and transmission electron microscopy. A comparative examination of the morphological features of the grains was conducted in an attempt to evaluate the importance of pollen morphology to the systematics of the family. Pollen morphology of the Styracaceae is rather uniform, with few variable features. Grains of nearly all examined species are solitary, mediumsized, radially symmetrical, tricolporate with lalongate endoapertures each with an equatorial bridge, and a tectate-perforate-columellate exine. The stratified exine has four consistent layers, including a well-developed tectum and an endexine that is often internally thinly fragmented along the mesocolpi and thickened under the colpi. Although the pollen of the family is relatively uniform, subtle variation is present, particularly in sculpturing type, where intertwined rugulate-reticulate, transitional fossulate-foveolate, finely rugulate, reticuloid, and weakly crotonoid exines occur. Outer tectal surfaces are smooth, granulose, microspinulose, beaded and banded. The large genusStyraxencompasses much of the pollen morphological variation observed within the family. Grains ofParastyraxare occasionally 4-aperturate and have especially thick exines. Pollen morphology of the Styracaceae is similar to that of Theaceae, with both families possessing basically tricolporate grains with a finely perforate or reticulate sculpturing pattern and a smooth outer tectal wall. It is suggested that within both families specialization has led to similar fossulate-finely rugulate and foveolate-fossulate sculpturing patterns with beaded or banded outer tectal walls.

ISSN:0017-3134    

DOI:10.1080/00173139209427822

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

InApium nodiflorumtwo kinds of exine-held material are observed: pollenkitt and residuals of the polysaccharidc primexine matrix. The latter is forming a loose texture inbetween the tectum elements, while pollenkitt exists in spaces between bacules as well as the outer exine surface. Furthermore the existance of an exinic outer membrane is discussed.

ISSN:0017-3134    

DOI:10.1080/00173139209427823

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The main stages of sporoderm ontogenesis in fertile Faba bean are at once shown like reference. In these plants, five running periods are recognized in the tapetum activity: 1) after the break-up of tetrads and the release of microspores in the anther cavity, theVicia fabatapetum presents an important secretory activity and its inner plasmalemma gets wavy. In the crypts thus formed and along the plasmalemma inner face a fibrillar network is developing, limited from the loculus by a thin pellicle with which it is in continuity. This whole structure constitutes the tapetum glycocalyx and reacts positively with ferric hydroxylammonium, PTA at low pH, PTA-acetone and PATAg; 2) at unpolarized microspore stage, many lipid droplets are accumulated in glycocalyx; 3) at polarized microspore stage, numerous membranous formations (F.M.), sometimes in continuity with the plasmalemma, are formed in the tapetum glycocalyx. In sixteen stamens on thirty, orbicules are not formed but the F.M. move in the anther cavity and are solely fixed on the ectoaperture edges of microspores. In fourteen stamens on thirty, membranous formations are embedded in a dense material and give rise to protoorbicules which move to the inner face of the tapetum pellicle; 4) during the microspore mitosis, the tapetum degenerates but keeps an undamaged plasmalemma with a normal glycocalyx on all its surface. F.M. and orbicules are increased; 5) in the course of pollen maturation, the tapetum decay is achieved and at anthesis are present only some broken membranes covered by a sporopollenin pellicle bearing orbicules.

ISSN:0017-3134    

DOI:10.1080/00173139209427824

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The suggestions that in the Lamiaceae 6-colpate pollen grains originate from 3-colpate ones and that this transition is connected with the transition from two-celled to three-celled male gametophytes have not been confirmed. 6-colpate pollen grains of the genusProstantheraare reported to be two-celled. It means that similar forms of 6-colpate pollen in systematic groups of Lamiaceae with two- and three-celled gametophytes originate independently.

ISSN:0017-3134    

DOI:10.1080/00173139209427825

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Rotorod samplers 1,2, and 3 m above ground level and O, 10, and 30 m downwind of a wheat canopy were used to measure dispersal and deposition ofPuccinia reconditaandP. graminisurediniospores, andErysiphe graminisandCladosporiumconidia under various meteorological conditions. Spore concentrations at 1 m decreased by 1.8% m-1over a 30 m distance downwind at canopy height with wind speeds above 12 km h-1and 2.7% m-1in winds of less than 10 km/hr. Spore concentrations at 1 m were significantly higher at the edge of the canopy than at 10 m and 30 m downwind. However, this was not true at 2 and 3 m above the ground, indicating that the decrease was due to spore deposition rather than upward movement of the spores. During sampling periods with winds greater than 10 km-h-1, spore impaction was reduced near the source and increased with increasing distance. However, wind velocities < 8 km h-1resulted in increased impaction near the source and decreased deposition with distance downwind from the source.

ISSN:0017-3134    

DOI:10.1080/00173139209427826

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A study of fungal airspora at Lucknow (26.55 N-80.59 E) in the University Campus, using a locally fabricated aeroscope for three consecutive years, starting from November 1982 to October 1984 resulted in the identification of 25 spore types. The genusAlternariarecorded highest spore count (15.30%) followed byCladosporium(10.02%),Fusarium(8.17%),Helminthosporium(7.35%) andCurvularia(7.03%) in decreasing order. The annual spore count ofAlternariain three consecutive years was 1788, 1897 and 1625, with a monthly range of 135–158 spores. The colonies ofAlternariaobtained in petridishes by gravity method during the same time, belonged to six species;Alternaria alternata, A. brassicae, A. brassicicola, A. citri, A. humicolaandA. pluriseptata. On the basis of their occurrence throughout the year, the species have been categorized in three groups. The three speciesA. alternata, A. humicolaandA. pluriseptata, which were reported as causal agents of onychomycosis were investigated for their allergenic manifestations also.

ISSN:0017-3134    

DOI:10.1080/00173139209427827

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The pattern and quantum of daily pollen release of thirty five plants of southern West Bengal were studied by counting their nature and time of anther dehiscence in one hour time interval in relation to meteorological condition. The results have been correlated with the atmospheric concentration of pollen grains in their surrounding environment by using rotorod sampler. The duration of pollen release varies from 2–12 h with a peak of 4–10 h. This result corroborates with the concentration of atmospheric pollen grains. It is noticed that pollen release intensity is high in short duration and vice versa. The variation of pollen release has also been observed in each species when meteorological condition gets changed abruptly.

ISSN:0017-3134    

DOI:10.1080/00173139209427828

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A continuous aeropalynological survey at Central Calcutta for two consecutive years (1985–1987) was done by using a Burkard Seven Day Recording Volumetric Spore Trap. A total of 65 pollen taxa was identified of which pollen ofTrema orientalisshowed a maximum frequency (about 68%) followed by Poaceae and Cyperaceae. A pollen calendar was prepared and seasonal periodicities were recorded. Some entomophilous pollen types (e.g.,Delonix regia, Bougainvillea spectabilis) were also observed. The presence of pollen ofPinus, Podocarpus, andAlnusin the air of Calcutta is probably due to long distance transport from Eastern Himalayas where these plants grow. Routine skin tests were performed by using the antigenic extracts of 22 pollen types where grass,Catharanthus roseus, Cocos nucifera, Azadirachta indica, Carica papaya, Albizia lebbek, Shorea robusta, Eucalyptussp.,Terminaliasp., were proved to be allergenically potent.

ISSN:0017-3134    

DOI:10.1080/00173139209427829

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Superoxid dismutase enzymes were isolated and identified in an aqueous extract of pollen and anthers ofZea maysand in two commercial products, Baxtin® and Polbax®, derived from the same kind of source material. Prior to analysis the samples were purified by adding soluble poly-Nvinylpyrrolidon and precipitated with ammonium sulphate,

ISSN:0017-3134    

DOI:10.1080/00173139209427830

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue

ISSN:0017-3134    

DOI:10.1080/00173139209427821

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor