ISSN:0017-3134    

DOI:10.1080/00173139809362644

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0017-3134    

DOI:10.1080/00173139809362645

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

In a palynological study of the Amaranthaceae, a peculiar type of reticulate pollen was found that is characterized by the presence of a porate aperture in each of the meshes of the reticulum. Previously, this type of pollen has been described as “reticulate”;. However, closer investigations show that the reticulum in pollen of Amaranthaceae is composed of mesoporia and pores. Consequently, this kind of reticulum represents a fundamentally different type, and is not homologous to the well known examples of pollen grains with a true reticulum (e.g. in Bromeliaceae, Lamiaceae). Therefore, the term “metareticulate”; is proposed (i.e., pantoporate pollen with a reticulum‐like structure of mesoporia and pores). The new term allows to distinguish between metareticulate and truely reticulate pollen, what is important in phylogenetic studies. Metareticulate pollen occurs only within lineages characterized by pantoporate pollen, and is found to be derived from pantoporate pollen in a cladistic analysis. Apart from the Amaranthaceae, metareticulate pollen evolved parallel in Vivianiaceae and Zygophyllaceae. In Caryophyllaceae and Convolvulaceae only a trend towards a metareticulation is observed. Metareticulate pollen is suggested as representing the highest developmental level in successiformy, which is one of the major patterns in pollen evolution leading from tricolpate to pantoporate grains.

ISSN:0017-3134    

DOI:10.1080/00173139809362646

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Pollen morphological studies of 19 species ofOryza(Poaceae) were carried out using LM and SEM. Eleven exine surface patterns are distinguished at x 20,000 magnification under SEM. These are categorised into three basic types: granulose, spinulose and insular.O. brachyantha‐a genomically unrelated species, and two species(O. granulataandO. meyeriana)comprising theO. meyerianacomplex have spinulose exine surfaces. TheO. ridleyicomplex which also contains two species(O. longiglumisandO. ridleyi)is characterised by a granulose exine pattern. In theO. officinaliscomplex and theO. sativacomplex, both granulose and insular exine patterns have been observed in different species. The largest pollen grains occur in theO. sativacomplex, which contains both cultivated species and their wild relatives.

ISSN:0017-3134    

DOI:10.1080/00173139809362647

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

L'étude de la morphologie du pollen deDacryodes edulisa montré qu'il est: isopolaire, tricolporé, longiaxe et possède une exine épaisse qui le prédispose à une conservation à long terme. La germinationin vitroest optimale sur le milieu de Brewbaker et Kwack additionné de 15 ou 20% de saccharose à pH 5,3. L'incubation se faisant à l'obscurité et à 30°C, la germination est rapide, près de 60% des pollens germent après une heure d'incubation, mais un temps supérieur à trois heures est nécessaire pour avoir une germination optimale et une élongation maximale du tube pollinique. Le pouvoir germinatif est de 8% après 24 mois de stockage à—20°C.

ISSN:0017-3134    

DOI:10.1080/00173139809362648

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

We report the use of anhydrous hydrogen fluoride as a new procedure to extract intact exine from a range of species. Pollen samples were incubated in anhydrous HF in pyridine for 5 hours at 40°C. Exines were recovered after several washes in water and ethanol. The quality of the exine obtained by this method has been followed by SEM micrographs and FT‐IR spectroscopy. The morphology of the pollen grains as determined by SEM was maintained after hydrogen fluoride treatment. FT‐IR spectra revealed that the chemical composition of the exine was not altered by this protocol. A comparison between this new protocol and the standard acetolysis method has been made. The new procedure presents two important advantages: it is short timing consuming and does not produce any chemical derivatization of the samples.

ISSN:0017-3134    

DOI:10.1080/00173139809362649

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Eleven samples of Brazilian propolis were analysed for their pollen content: seven from the state of Rio de Janeiro, three from Minas Gerais and one from Rio Grande do Sul. A standard methodology for the analysis of Brazilian samples of propolis in terms of their pollen content is proposed. The preparation of a sample of the sediment just prior to acetolysis is useful in order to examine plant hairs (trichomes) and other plant structures not resistant this procedure. The most important pollen types detected wereEupatorium‐type, Cecropia‐type andEucalyptus‐type each one certainly comprising more than one plant species with similar morphology.Mimosa caesalpiniaefoliatype dominated in a sample collected next to the city of Rio de Janeiro. It was possible to characterize a sample coming from the state of Rio Grande do Sul relative to the samples obtained from the two other states. The influence of the large city of Rio de Janeiro could be recognized in the pollen spectra of propolis collected in its vicinity. Pollen of plant species characteristic of the southeast Atlantic forest could be determined in some samples. The importance of pollen grains from anemophilous plant species is emphasized.

ISSN:0017-3134    

DOI:10.1080/00173139809362650

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The melissopalynological analysis of eight honey samples from five different apiaries on La Palma (Canary Islands) where avocado(Persea americana)pollen was found is presented. Avocado pollen was always found in low proportions except in one honey that proved to be unifloral.

ISSN:0017-3134    

DOI:10.1080/00173139809362651

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The relationship between the timing of olive pollination and some parameters which can influence this phenomenon was investigated. A model is presented which shows a strong relationship between timing of pollination, selected meteorological variables (temperature and precipitation) and annual pollen quantity. The most important correlations are with mean temperature in February, and precipitation in May. The positive correlation with annual pollen quantity confirms the relationship of this variable to the time of pollination.

ISSN:0017-3134    

DOI:10.1080/00173139809362652

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A Cour trap was used to sample the air of Seville of continuously from 1987 to 1996. The most important climatological feature recorded during that period was the drought that began in 1990 and which was at its most severe in the first half of 1995.

ISSN:0017-3134    

DOI:10.1080/00173139809362653

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor