scholarly journals The difference between pollen types and plant taxa: a plea for clarity and scientific freedom

2007 ◽  
Vol 56 (3) ◽  
pp. 162-171
Author(s):  
Pim De Klerk ◽  
Hans Joosten
Keyword(s):  
Pollen Type ◽  
Scientific Freedom ◽  
Pollen Types ◽  
Common Problems ◽  
The Difference ◽  
Unconventional Methods

Abstract. This paper discusses the character of pollen types. We argue that pollen types and plant taxa are completely different entities (morphological and taxonomical respectively) and therefore should be treated and displayed differently. Common problems in conventional pollen type nomenclature are illustrated with examples from present day European palynological practice. We plead for clarity in pollen type nomenclature and for the scientific freedom to use 'unconventional' methods to avoid confusion.

Sporoderm morphogenesis in Euphorbia obesa and Croton gratissimus

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 849-856 ◽  
Author(s):  
M. L. Frean
Keyword(s):  
Pollen Morphology ◽  
Pollen Grains ◽  
Physiological Adaptation ◽  
Structure Characteristic ◽  
Pollen Type ◽  
Electron Microscope Level ◽  
Pollen Characters ◽  
Pollen Types ◽  
Unisexual Flowers ◽  
Taxonomic Grouping

Pollen grains of the Euphorbiaceae show a number of pollen types which can be clearly distinguished. Generally different genera are characterized by a specific pollen type.  Euphorbia obesa Hook. f. and Croton gratissimus Burch, subsp.  subgratissimus (Prain) Burtt Davy, represent two genera within the Crotonoideae with different morphology, each type characteristic for the respective genus. Taxonomically, the genus Euphorbia with apetalous flowers consisting of a naked pistil surrounded by several staminate flowers within a cyathium, is considered more advanced than the genus  Croton. In  Croton the inflorescence is a raceme with unisexual flowers. The floral whorls of the male show numerous anthers and both calyx and a showy corolla are present. Both genera are insect pollinated. In both  Euphorbia obesa and  Croton gratissimus the pollen wall in section shows columellae, a structure characteristic of angiosperms. However the present ontogenetic studies show that the formation of the columellae differs entirely in the two pollen types. The final stratification of the wall as well as the morphology of the grains differ and evaluation of the exine structure indicates that phylogenetically Croton pollen shows more advanced characters than  Euphorbia — contradicting the floral phylogeny. This study conducted at light and electron microscope level compares the two pollen types morphologically and ontogenetically, concentrating mainly on the formation of the exine which is tectate-perforate in the prolate tricolpate grain of Euphorbia obesa and semi-tectate in the anaperturate, spheroidal grain of Croton gratissimus. The aim of the study was to evaluate the significance of pollen characters in taxonomic and phylogenetic relationships within the Euphorbiaceae. The differing pollen morphology which is related to the taxonomic grouping of tribes within the subfamily (Crotonoideae) emphasizes diversity, which may result from physiological adaptation. The study shows that the same functional end may well be achieved in different ways and this may be a factor underlying the diversity in the heterogeneous family Euphorbiaceae.

Comparative Study of Airborne Pollen from the Northern to the Southern of Tunisia

2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Hadj Hamda ◽  
A. Ben Dhiab ◽  
M. Msallem ◽  
A. Larbi
Keyword(s):  
Crop Production ◽  
Airborne Pollen ◽  
Flowering Phenology ◽  
Plant Distribution ◽  
The South ◽  
Pollen Type ◽  
The North ◽  
Flowering Season ◽  
Pollen Types ◽  
Study Sites

Aerobiology is a multidisciplinary science dealing with biological particles in the atmosphere generated by natural activities during flowering season. Airborne pollen is now the main studied biological structure which is used as a reliable tool to study plant phenology, plant distribution changes and prediction of crop production. The main aims of this work is to determine the distribution of the different spring flowering species from the North to the South of Tunisia and to establish the pollen spectrum of three regions Mornag (North), Menzel M’hiri (Centre) and Chaal (South) in 2017. Airborne pollen data were collected using three volumetric Hirst-type spore traps placed in Mornag (36°39N; 10°16E), Menzel M’hiri (35°38N; 10°41E) and Chaal (34°34N; 10°19E) during olive flowering season. The highest pollen index was recorded in the north (Mornag, 6487.1) corresponding mainly to 18 different pollen types emitted by anemophilous species with an important presence of Cupressus pollen type having the highest contribution. Lower pollen amounts were recorded in Menzel M’hiri (5983.8) and Chaal (925.3). Olea eurpoeae was the most presented pollen type in these regions. However comparing the different study sites we can note a large distribution of some taxa from north to the south. The main common taxa were Olea europaea, Cupressaceae, Poaceae and Amaranhaceae. Their atmospheric concentrations varied also between the regions. Individual pollen index showed a sharp heterogeneity between the taxa in the same region in one hand and between the study sites in the other hand, thus a statistical analysis was performed to define the main group of taxa according to their individual pollen index. Flowering phenology of the main common taxa was also established.

scholarly journals Pollen analysis in honey samples from the two main producing regions in the Brazilian northeast

2007 ◽  
Vol 79 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Geni da S. Sodré ◽  
Luís C. Marchini ◽  
Carlos A.L. de Carvalho ◽  
Augusta C. de C.C. Moreti
Keyword(s):  
Quantitative Analysis ◽  
Pollen Analysis ◽  
Sao Paulo ◽  
The State ◽  
São Paulo ◽  
Pollen Type ◽  
Northeastern Region ◽  
Pollen Types ◽  
Abundant Supply ◽  
Brazilian Northeast

Knowledge about the botanical source of honey is very important for the beekeeper while it indicates adequate and abundant supply sources of nectar and pollen for the bees, thus contributing toward improved yield. The present study means to identify the pollen types occurring in 58 samples of honey produced in two states of the northeastern region of Brazil, Piauí (38 samples) and Ceará (20 samples), and to verify the potential of the honey plants during the months of February to August. The samples were obtained directly from beekeepers in each state and analyzed at the Apiculture Laboratory of the Entomology Section of Escola Superior de Agricultura "Luiz de Queiroz", USP, Piracicaba, State of São Paulo, Brazil. The pollen analysis was performed using the acetolysis method. The samples were submitted to both a qualitative and a quantitative analysis. The dominant pollen in the State of Ceará is from Mimosa caesalpiniaefolia, M. verrucosa, Borreria verticillata, Serjania sp., and a Fabaceae pollen type, while in the State of Piauí it is from Piptadenia sp., M. caesalpiniaefolia, M. verrucosa, Croton urucurana and Tibouchina sp.

The Contrast between the Models’ in PSD-BPA and those in PSASP

2012 ◽  
Vol 614-615 ◽  
pp. 1055-1064
Author(s):  
Chang You Yan ◽  
Min Wang ◽  
Jing Jing Lu
Keyword(s):  
Power System ◽  
Power Flow ◽  
System Analysis ◽  
Transfer Functions ◽  
Research Work ◽  
Power Flow Calculation ◽  
Power System Analysis ◽  
The Common ◽  
Common Problems ◽  
The Difference

Both PSD-BPA and PSASP are all important power system analysis tools. The aim in this paper is the models’ contrast and studing the difference between PSD-BPA and PSASP. First by the models contrast, the experience will be summed up. The method of model contrast is to deduce the transfer functions in order to find the differences of transfer functions between PSD-BPA and PSASP, so as to analyze the difference. After the research work, the discussion and study on the common problems will be taken and the rational advice will be put forward in the power flow calculation. The common problems in the transient calculation will be expounded, and the result will be tabled in order that these contents are obvious at a glance. At last the conclusion will be brought forward and some pieces of advice will be summed up.

scholarly journals Melissopalynological analysis of honey produced by two species of stingless bees in Lombok Island, Indonesia

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Lalu Zulkan Jayadi ◽  
Ratna Susandarini
Keyword(s):  
Stingless Bees ◽  
Geographical Origin ◽  
Botanical Origin ◽  
Pollen Type ◽  
Pollen Content ◽  
Pollen Types ◽  
Unifloral Honey ◽  
Melissopalynological Analysis ◽  
Lombok Island ◽  
Number Of Plant Species

Abstract. Jayadi LZ, Susandarini R. 2020. Melissopalynological analysis of honey produced by two species of stingless bees in Lombok Island, Indonesia. Nusantara Bioscience 12: 97-108. Honey is a natural product with a variety of benefits that commonly used as food sweeteners, health supplements, and traditional medicine. There has been no comprehensive publication regarding the diversity of pollen contained in honey produced by stingless bee Tetragonula laeviceps and Heterotrogona itama from Lombok. This study aimed to reveal the diversity of pollen content in honey through melissopalynological analysis of honey samples produced by two species of stingless bees T. laeviceps and H. itama in Lombok Island. This melissopalynological study was performed on honey samples obtained from nine villages from nine sub-districts representing the three districts on Lombok Island. Pollen extraction from honey was carried out using standard methods for melissopalynological analysis. The diversity of pollen recovered from honey varied from 15 to 41 pollen types. Total number of plant species whose pollen was recovered from honey samples was 127 which consisted of 61 families. The occurrence of predominant pollen type in particular unifloral honey samples indicated their botanical origin and presumed geographical origin of honey. Results of this study are useful in confirming botanical origin of honey and generating information on plants potential as food source for sustainable beekeeping in Lombok Island.

scholarly journals Research of traditional village Conservation and Development Planning. Taking Liugou Village in Beijing as an example

2019 ◽  
Author(s):  
Zhengkun Gan ◽  
◽  
Lingege Long ◽  
Dayu Zhang ◽  
◽  
...  
Keyword(s):  
High Speed ◽  
Planning Process ◽  
Development Planning ◽  
Protection Measures ◽  
Conservation And Development ◽  
Planning Framework ◽  
Long Time ◽  
Common Problems ◽  
The Difference ◽  
Effective Conservation

As a primary material carrier of Chinese farming civilization, traditional villages have the dual attributes of villages and heritage. The traditional village cannot be regenerated if they were destroyed. Therefore, it is urgent to find a suitable development model and way out in the context of high-speed urbanization. The proper planning of traditional villages mainly covers two aspects of protection and development for a long time. The preparation and management of various types of planning are also intertwined and even contradictory. “Multiple-planning” is an effective way to solve the conflicts between different administrative departments and different types of planning in the current planning process, and also provides a practical planning idea and method for the future of traditional villages. Firstly, the research analyzes the existing planning types of traditional villages and points out that because of the difference of objectives, strategies, and executives, there come three common problems: The protection measures are not easy to implement; The development strategies are unsustainable; The planning and implementation are not connected. These problems directly affected the implementation of planning. They not only hinder the effective conservation of cultural heritage but also restrict the revitalization of the village's economic development. Furthermore, the research discusses the necessity and feasibility of “Multiple-planning” in the conservation and development of traditional villages and proposes a conservation and development planning framework for traditional villages from the perspective of “Multiple-planning.” Finally, the research is taking a traditional village conservation and development planning of Liugou in Yanqing District of Beijing as an example. Accomplished valuable planning in the perspective of “Multiple-planning” through objective and systematic status analyzing, exceptional and feasible conservation planning, scientific and sustainable development planning.

Morphologie pollinique des Cupressaceae de l'est du Canada et du nord-est des États-Unis appliquée à l'étude des sédiments quaternaires

1990 ◽  
Vol 68 (1) ◽  
pp. 79-89 ◽  
Author(s):  
Johanne Parent ◽  
Pierre J. H. Richard
Keyword(s):  
Pollen Morphology ◽  
Pollen Grains ◽  
Taxodium Distichum ◽  
Juniperus Virginiana ◽  
Eastern Canada ◽  
Pollen Type ◽  
Thuja Occidentalis ◽  
Chamaecyparis Thyoides ◽  
Identification Criterion ◽  
Pollen Types

The pollen morphology of seven species, varieties and forms of Cupressaceae from eastern Canada and northeastern United States was studied by light microscopy, following acetolysis, to improve the identification of these taxa in Quaternary fossil sediments. Taxodium distichum (Taxodiaceae), which is also present in the study area, was included for comparison. Four pollen types were defined: Juniperus communis – Thuja occidentalis, Chamaecyparis thyoides, Juniperus horizontalis – Juniperus virginiana, and Taxodium distichum. Five shapes of pollen grains exist: whole, slightly split, opened in a "V" shape, spindlelike, or split in halves. All shapes are found in all species, in varying proportions, and represent different stages of hydration in Cupressaceae pollen type. The absence or presence of these shapes cannot be used as an identification criterion for the different species. A pollen identification key, applicable to fossil sediments and combining characters based on shape, size and other morphological features of acetolysed grains, is proposed and allows to differentiate all the species from one another, with the exception of Juniperus horizontalis and Juniperus virginiana.

The systematic value of pollen morphology of Passiflora subgenus Astrophea (Passifloraceae)

Phytotaxa ◽  
2017 ◽  
Vol 298 (1) ◽  
pp. 1 ◽  
Author(s):  
ANA CAROLINA MEZZONATO-PIRES ◽  
CLÁUDIA BARBIERI FERREIRA MENDONÇA ◽  
MICHAELE ALVIM MILWARD-DE-AZEVEDO ◽  
VANIA GONÇALVES-ESTEVES
Keyword(s):  
Great Degree ◽  
Pollen Morphology ◽  
Multivariate Analyses ◽  
Type I ◽  
Pollen Type ◽  
Type Iv ◽  
Quantitative Characters ◽  
Pollen Characters ◽  
Pollen Types ◽  
Degree Of Similarity

This study investigates and reports the pollen morphology of a selected group of Passiflora species of the subgenus Astrophea. We found that species can be grouped into five pollen types, four of which had been previously documented. The fifth new pollen type was observed in P. macrophylla. This pollen type completely lacks muri, and possesses spines and bacula on a granulate surface. All of the species of the subgenus Astrophea studied have the same type of aperture: 6-colporate with 3 lalongate endoapertures, one for each pair of ectoapertures. Multivariate analyses performed with quantitative characters showed a great degree of similarity between type I, II and V pollen, and individual distinction of type III and type IV. The pollen characters observed do not support the currently accepted taxonomic classification for the Passiflora subgenus Astrophea, but are useful for delimiting species.

scholarly journals EL POLEN DE HELICTERES (STERCULIACEAE) y SU COMPARACIÓN CON GÉNEROS VECINOS

Bonplandia ◽  
2001 ◽  
Vol 11 (1-4) ◽  
pp. 207 ◽  
Author(s):  
Stella M. Piré ◽  
Carmen L. Cristóbal
Keyword(s):  
Pollen Grains ◽  
Pollen Grain ◽  
The Other ◽  
Type I ◽  
Evolutionary Trend ◽  
Equatorial Zone ◽  
Pollen Type ◽  
Type Viii ◽  
Exine Sculpture ◽  
Pollen Types

<p>Pollen grains of 41 species representing all seven sections of Helicteres were studied with light and scanning electron microscopy and described. In order to establish palynological affinities Neoregnellia cubensis, Kleinhovia hospita, Reevesia thyrsoidea, Veeresia clarkii, Ungeria floribunda and Pterospermum acerifolium were also examined. Helicteres is palynologically rather uniform with respect to the shape and size of the grains as well as the type and number of the apertures. The pollen grains are usually triporate, oblate or suboblate, amb triangular and medium sized. Nevertheless the exine surface shows great variability. Nine pollen types are recognized on the basis of the sculpture of the exine: Type 1, tectate-perforate, baculate, in sect. Helicteres; Type 11, tectate-perforate, psilate to weakly verrucate, in 4 species of sect. Orthocarpaea; Type 111, tectate-perforate, with the equatorial zone verrucate and the poles psilate, in sect. Stegogamos; Type IV, microreticulate, verrucate, in sect. Polyandria; Type V, tectate, scabrate, verrucate, in sect. Alicteres; Type VI, tectate-perforate, verrucate, in 2 species of sect. Orthocarpaeaand 4 species of sect. Orthothecium; Type VII, tectate-perforatefossulate, verrucate, the verrucae large, irregular in outline, often anastomosed, in 3 species of sect. Orthothecium; Type VIII, tectate to tectate-perforate-fossulate, perforations and fossulae as well as micro-verrugae and micro-echinae densely concentrated at the poles, the equatorial zone psilate or scabrate, in 3 species of sect. Orthothecium; Type IX, tectateperforate- fossulate, microechinate, the perforations and fossulae densely concentrated at the poles, the micro-echinae distributed throughout the surface but hardly differentiated on the poles, in 16 species of sect. Sacarolha and 5 species of sect. Orthothecium. The pollen types are ordered according to the complexity of the exine; with the types with uniform sculpture considered simpler and the types with polar and equatorial zones differentiated considered complex. Keys to identify the nine pollen types of Helicteres and the pollen types of related genera are presented. According to pollen morphology Neoregnellia is closely connected with Helicteres; this genus shares the same pollen type, IX, with sect. Sacarolha and some species of sect. Orthothecium. The pollens of Kleinhovia and Helicteres have many characters in common (shape, size, apertures), the only difference being the microreticulate surface of the former; they are rather close to each other. Reevesia thyrsoidea, Veeresia clarkii and Ungeria floribunda stand apart from Helicteres in having 3-5 brevi-colp(or)ate and suprareticulate grains. The very distinctive pollen of Pterospermum acerifolium (Iarge size, spheroidal, echinate) supports its segregation from the tribe Helictereae. In Helicteres the different patterns of exine sculpture have taxonomic and phylogenetic value. In the first place, they allow the recognition of the 4 monospecific sections (Helicteres, Stegogamos, Alicteres and Polyandria) and at the same time they reveal the coherence of the genus, since the other 3 sections which have many species (Orthocarpaea, Orthothecium and Sacarolha) are connected with each other not only by exomorphological characters but also by pollen characters. In the second place, they provide bases for interpreting infra-generic relationships and the possible origin of the genus.Two possible evolutionary trends of exine sculpture, which are representated in two diagrams, are proposed. The first possibility starts with the Type VI; from this pollen type the evolutionary trend would have diverged in several directions. On one side, a line would lead toward increasing complexity of the exine that would end in Type VIII. This kind of pollen grain would have given rise to Type IX. On the other side, several divergent lines might have taken place; modifications in the exine sculpture would have led toward a progressive simplicity that would culminate in the absence of sculptural elements of Type 11. From this kind of pollen grain Type I might have evolved. The second possibility starts from Type 11; in this case the evolutionary trend of the exine would have gone in only one direction; the exine would have acquired more and more complexity, giving rise to pollen types connected with each other by transitional forms.</p>

History of the family Malpighiaceae in Australia and its biogeographic implications: evidence from pollen

2002 ◽  
Vol 50 (2) ◽  
pp. 171 ◽  
Author(s):  
Helene A. Martin
Keyword(s):  
Fossil Record ◽  
Pollen Type ◽  
Tropical Regions ◽  
Centre Of Origin ◽  
Eastern Australia ◽  
Pollen Types ◽  
The Family ◽  
North Eastern ◽  
History Of ◽  
Northern South America

Three pollen types of the family Malpighiaceae have been identified in the Tertiary fossil record of south-eastern Australia. There are two species of the family native to Australia and they have the same pollen type. There was thus a greater diversity of malpighiaceous taxa during the Tertiary than there is today. The family is found mainly in tropical regions and it is thought that northern South America was the centre of origin. The restriction of the two species to coastal north-eastern Australia suggests recent migration into the area and gives no hint of the long history of the family in Australia.

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