scholarly journals Using of Taraxacum officinale (L.) pollens for the urban park bioindication

2020 ◽  
Vol 10 (5) ◽  
pp. 49-53
Author(s):  
M. Mazura ◽  
N. Miroshnyk ◽  
I. Teslenko
Keyword(s):  
General Trend ◽  
Gradual Increase ◽  
Pollen Grains ◽  
Sublethal Effect ◽  
Taraxacum Officinale ◽  
Urban Ecosystem ◽  
Pollen Sterility ◽  
Anthropogenic Load ◽  
Ecological Situation ◽  
Pollution Gradient

Palinoindication of 6 parks of the urban ecosystem of Kiev using Taraxacum officinale (L.) Weber ex F.H. Wigg. population, was carried out. There is a general trend towards an increase in the amount of nonviable pollen with an increase in anthropogenic load. In the example of T. officinale, this is manifested in a gradual increase to 27% of non-viable pollen on the pollution gradient. With the deterioration of the ecological situation in the studied test polygons, an increase in the number of teratomorphic pollen grains up to 41.10% in Babin Yar tract was recorded. According to the level of palynotoxic action (PE, %), only 2 gradations were revealed in the parks under study: initial and effective. The sublethal effect (highly toxic) has not been established, since the level of pollen sterility in our studies did not exceed 45,2%. The largest number of pollen grains with developmental pathologies (teratomorphic) – 41.10% – was recorded in the Babin Yar tract, the state of which, according to the anthropogenic load index (Jal), is characterized as poor. At the same time, the percentage of teratomorphic pollen grains in T. officinale plants in more favorable environmental conditions (control) does not exceed 16.50%. For the bioindication assessment of the park ecosystems state in the megalopolis, the most indicative were the index of sterility, palynotoxic effect and the content of teratomorphic pollen grains, which increases with the gradient of anthropogenic load.

scholarly journals Pollen and Spikelet Analysis in F1 Rice Hybrids and their Parents

2014 ◽  
Vol 8 ◽  
pp. 120-126 ◽  
Author(s):  
Bal K. Joshi ◽  
Laxmi P. Subedi ◽  
Santa B. Gurung ◽  
Ram C. Sharma
Keyword(s):  
Pollen Fertility ◽  
Practical Importance ◽  
Pollen Grains ◽  
Gene Interaction ◽  
Pollen Sterility ◽  
Spikelet Fertility ◽  
High Fertility ◽  
Male Sterile ◽  
Pollen Abortion ◽  
Spikelet Sterility

Pollen analysis can be used to discriminate between different species, identify possible  interspecies hybrids, identify restorer and maintainer lines, useful to study genetics of  restorer gene, interaction between chromosome and cytoplasm and relationship between  parents. Pollen abortion system of male sterility is an important tool in hybrid rice  production and spikelet is the major yield components. Nine improved cultivars, six  landraces and three wild aborted cytoplasmic-genetic male sterile (CMS) lines were used to  analyze pollen and spikelet in F1 rice hybrids and their parents. The frequency of pollen  categories and its relationship to spikelet fertility were investigated. Pollen sterility of the  F1s was determined by staining pollen grains in 1% potassium iodide-iodine (I-KI) solution.  Spikelet fertility was determined by counting the total number of seed set in proportion to  the total number of spikelets. Correlation and regression coefficients for some traits were  computed. In hybrids, pollen fertility ranged from 0.5 to 82% and spikelet fertility from 0 to  87%. Pollen fertility varied from 28 to 97%, while spikelet fertility from 73 to 91% in pollen  parents. The highest and the lowest percentages of pollen fertility were found in Chaite-6  and Chiunde cultivars respectively. Spikelet fertility percentage varied widely among  hybrids and many hybrids had lower spikelet fertility percentage than their parents.  Therefore, it is of practical importance to understand the causes of high spikelet sterility in  hybrids for possible increase in spikelet fertility. Highly significant positive correlation was  found between stained round fertile (SRF) pollen and spikelet fertility. The positive value of  correlation and regression coefficient on SRF and spikelet fertility were found between F1  and mid parent, and F1 and male parent. High fertility of cross may be due to the presence of  a wide compatibility gene or restorer genes in the cultivar. Lower pollen and spikelet  fertility of the crosses was attributed to effect of the genetic background of the tester parent. Nepal Agric. Res. J. Vol. 8, 2007, pp. 120-126 DOI: http://dx.doi.org/10.3126/narj.v8i0.11605  

Pollen Quality in Woody Plants in the City Parks of Dnipro, Ukraine

2016 ◽  
Vol 59 ◽  
pp. 29-37
Author(s):  
Olga Ivanchenko ◽  
Valentina Bessonova
Keyword(s):  
Woody Plants ◽  
Pollen Grains ◽  
Anthropogenic Pollution ◽  
Pollen Sterility ◽  
Industrial Complex ◽  
Acer Platanoides ◽  
Pollen Quality ◽  
City Parks ◽  
Sterile Pollen ◽  
The City

This research was conducted to study pollen quality in woody plants in the city parks of Dnipro, which are located at various distances from the sources of anthropogenic pollution. It has been revealed that sterile pollen in its greatest abundance was present in plant species in the Park of Memory and Reconciliation and Molodyozhny park, as both are situated within the range of emission transfer from the Western Industrial Complex, while the least abundant sterile pollen was detected in the park named after Yu. Gagarin and that named after V. Dubinin. According to sterility indices, the pollen inBetula pendulaRoth. and that inAcer platanoidesL. were most sensitive to environmental pollution. In the city parks, the amounts of shrunk and abnormally shaped pollen grains increases; giant forms with grain diameters exceeding standard, as well as dwarf forms are not rare in occurrence. The highest percentage of pollen grains of atypical shape and size was observed in the same parks where the pollen sterility index had its highest values.

scholarly journals The morphology of pollen presenter and polymorphism of pollen grains Taraxacum officinale F. H. Wigg.

2012 ◽  
Vol 59 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil
Keyword(s):  
Plant Material ◽  
Outer Part ◽  
Pollen Grains ◽  
Taraxacum Officinale ◽  
City Centre ◽  
Entire Surface ◽  
High Viability ◽  
Electron Scanning Microscopy ◽  
Pollen Release ◽  
The City

The study of the structure of the pollen presenter of <i>Taraxacum officinale</i> and morphology of pollen grains was conducted based on plant material sampled from three different sites. One of them was a forest meadow situated away from the city, and the other two were located in the city centre of Lublin. Light and electron scanning microscopy were used in the study. The pollen presenter in <i>Taraxacum officinale</i> occurs at the upper part of the style situated over the androecium and on the outer part of the stigma. Numerous unicellular trichomes are found on the entire surface of the epidermis of the presenter. The function of the presenter consists in transferring pollen grains above the androecium and corolla petals. Its activity does not stop after pollen release from anthers. <i>Taraxacum</i> pollen grains represent the <i>Crepis</i> - type. Most frequently, they are <i>tricolporate</i>, radially symmetric and isopolar. In terms of the size, they are included in medium-sized grains. In the material examined, many deformed and asymmetric grains were observed, though they were marked by high viability at the level of 96.5-99%. Grains with the largest average lengths of the equatorial and polar axes were found in plants sampled from the meadow situated out of town. In the plant material from all sites, grains with disturbances of the external structure occurred.

scholarly journals Thinning of the Ice Sheet Estimated from Total Gas Content of Ice Cores in Mizuho Plateau, East Antarctica

1990 ◽  
Vol 14 ◽  
pp. 131-135 ◽  
Author(s):  
Takao Kameda ◽  
Masayoshi Nakawo ◽  
Shinji Mae ◽  
Okitsugu Watanabe ◽  
Renji Naruse
Keyword(s):  
Linear Relation ◽  
Vertical Profile ◽  
General Trend ◽  
Gradual Increase ◽  
Ice Core ◽  
Ice Sheet ◽  
Ice Cores ◽  
Gas Content ◽  
Ice Formation ◽  
Slope Flow

A linear relation between total gas content in ice and the elevation of ice formation (i.e. pore close-off) was obtained from seven shallow ice cores in Mizuho Plateau, Antarctica. The derived relation was applied to the vertical profile of total gas content in a 700 m long ice core at Mizuho Station. A general trend of gradual increase in total gas content was observed from 600 to 200 m in depth, from which toward the upper layer it showed a steep increase. After eliminating the effect of down-slope flow of ice around Mizuho Station, it was estimated that the thickness of the ice sheet decreased by about 350 m at maximum during the last 2000 years. This tendency also appears in the δ18O profile of the same ice core.

scholarly journals Quantitative methods in microscopy to assess pollen viability in different plant taxa

2020 ◽  
Vol 33 (3-4) ◽  
pp. 205-219
Author(s):  
Lorenzo Ascari ◽  
Cristina Novara ◽  
Virginia Dusio ◽  
Ludovica Oddi ◽  
Consolata Siniscalco
Keyword(s):  
Statistical Power ◽  
Quantitative Methods ◽  
Pollen Viability ◽  
Crop Improvement ◽  
Pollen Grains ◽  
Pollen Sterility ◽  
Pollen Grain ◽  
Automated Image Analysis ◽  
Future Research ◽  
Sterile Pollen

AbstractHigh-quality pollen is a prerequisite for plant reproductive success. Pollen viability and sterility can be routinely assessed using common stains and manual microscope examination, but with low overall statistical power. Current automated methods are primarily directed towards the analysis of pollen sterility, and high throughput solutions for both pollen viability and sterility evaluation are needed that will be consistent with emerging biotechnological strategies for crop improvement. Our goal is to refine established labelling procedures for pollen, based on the combination of fluorescein (FDA) and propidium iodide (PI), and to develop automated solutions for accurately assessing pollen grain images and classifying them for quality. We used open-source software programs (CellProfiler, CellProfiler Analyst, Fiji and R) for analysis of images collected from 10 pollen taxa labelled using FDA/PI. After correcting for image background noise, pollen grain images were examined for quality employing thresholding and segmentation. Supervised and unsupervised classification of per-object features was employed for the identification of viable, dead and sterile pollen. The combination of FDA and PI dyes was able to differentiate between viable, dead and sterile pollen in all the analysed taxa. Automated image analysis and classification significantly increased the statistical power of the pollen viability assay, identifying more than 75,000 pollen grains with high accuracy (R2 = 0.99) when compared to classical manual counting. Overall, we provide a comprehensive set of methodologies as baseline for the automated assessment of pollen viability using fluorescence microscopy, which can be combined with manual and mechanized imaging systems in fundamental and applied research on plant biology. We also supply the complete set of pollen images (the FDA/PI pollen dataset) to the scientific community for future research.

Fertility and Viability of Pollen Grains of Taraxacum officinale Wigg. s.l. (Asteraceae, Magnoliopsida) in a Gradient of an Anthropogenically Transformed Environment

2020 ◽  
Vol 47 (10) ◽  
pp. 1351-1358
Author(s):  
T. V. Zhuikova ◽  
V. S. Bezel’ ◽  
I. E. Bergman ◽  
E. V. Meling ◽  
A. V. Krivosheeva
Keyword(s):  
Pollen Grains ◽  
Taraxacum Officinale

Impact of high temperature on pollen germination and spikelet sterility in rice: comparison between basmati and non-basmati varieties

2010 ◽  
Vol 61 (5) ◽  
pp. 363 ◽  
Author(s):  
Bidisha Chakrabarti ◽  
P. K. Aggarwal ◽  
S. D. Singh ◽  
S. Nagarajan ◽  
H. Pathak
Keyword(s):  
High Temperature ◽  
Pollen Germination ◽  
Rice Yield ◽  
Pollen Grains ◽  
Pollen Sterility ◽  
Basmati Rice ◽  
Pollen Deposition ◽  
Spikelet Sterility ◽  
Rice Varieties ◽  
Increased Temperature

Increased temperature due to global warming may reduce pollen germination and induce spikelet sterility in rice crops. Anthesis is the most sensitive stage in rice and exposure to high temperature during this period may cause reduction in floral reproduction. Increased temperature will have different effects on different rice varieties. In the present study the effect of high temperature on pollen as well as on spikelet sterility in basmati (aromatic) and non-basmati (non-aromatic) rice varieties was quantified. Rice varieties were grown at 11 different sowing dates, to see the effect of varying temperature on pollen and spikelet sterility. Rise in temperature increased pollen sterility and reduced germination of pollen grains on the stigma. Temperature above 33°C during anthesis gradually increased pollen sterility in all rice cultivars. At 35.5°C, variety Pusa Sugandh 2 (basmati) recorded a pollen sterility of 17% and 26% reduction in pollen germination. The principal cause of sterility was reduced anther dehiscence and less pollen deposition on the stigma at higher temperature. Increased temperature during the grain-filling period also increased spikelet sterility in rice and variety Pusa Sugandh 2 was most affected. Non-basmati rice varieties were less affected by increased temperature than basmati types. The study indicated that increasing temperature could limit rice yield by affecting pollen germination and grain formation. It also suggested that sensitivity of pollen grains to temperature damage could be taken as one of the most important parameters for predicting rice yield in warmer climates.

Microsporogenesis, pollen mitosis and pollen tube growth in Gagea villosa (Liliaceae)

Biologia ◽  
2014 ◽  
Vol 69 (10) ◽  
Author(s):  
Nuran Ekici
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Grains ◽  
Middle Layer ◽  
Pollen Sterility ◽  
Tube Growth ◽  
Anther Wall ◽  
Pollen Mitosis

AbstractIn this study, Gagea villosa (Bieb.) Duby was investigated by using light microscopy methods in cytological and cytoembryological respects. Anthers were tetrasporangiate. Anther wall was formed with an epidermis, endothecium, middle layer and tapetum. Tapetum was glandular type and it began to degenerate when microspores released from tetrads. Tapetum cells generally have one or two nuclei. Mitosis seen in tapetum cells was generally normal but micronuclei were found in some of them. Fibrous thickenings were determined in endothecium. Microsporogenesis and pollen mitosis were generally regular. Cytokinesis was successive type. Meiosis in pollen mother cells was asynchronous in one anther locus. Mature pollen grains were 2-celled. Pollen sterility was found to be 24%. Some of the fertile pollen grains, smaller than the normal were seen at the end of the pollen mitosis. Microgametophyte development was examined in vivo and in vitro. Germination ratio of pollen grains in vitro was 4%. Generally swollen pollen tube tips and weak development of some curled pollen tubes were seen. Callose plug formation was seen only in vivo pollen tube growth.

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