scholarly journals Fertility and Progeny Ploidy of Triploids in China Rosa Germplasm

2020 ◽  
Author(s):  
Hui Feng ◽  
Naizhe Ji ◽  
Yu Xie ◽  
Beibei Ge ◽  
Yanhua Bu ◽  
...  
Keyword(s):  
Ploidy Level ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Size ◽  
Rosa Multiflora ◽  
Viable Pollen ◽  
Wide Range ◽  
The Future ◽  
Interploidy Crosses ◽  
Species Evolution

Abstract Background Although triploid plants are often assumed to be sterile, in Rosa, triploids appear to have been important in both species evolution and breeding. A better understanding of the fertility of China Rosa triploids and their behavior when used in interploidy crosses will not only improve gene introgression from China triploid roses to modern roses, but also enhance our understanding of male and female fertility mechanism with triploids. The objective of this study was to evaluate the usefulness of five triploid China roses for breeding by measuring the pollen size, quantifying the fertility and following the ploidy transmission of interploidy crosses. Results In the five triploids, the pollen grain size of Rosa multiflora var. cathayensis Rehd ‘Fen Tuan Qiang Wei’ followed a normal distribution, suggesting that 1 mainly ploidy level pollen grain were produced, while the pollen size of other 4 triploids followed skewed, flattened, and slightly bimodal distributions, indicating a wide range of chromosome numbers. Although none of the 5 triploids produced hips as females, 3 gave good hip and seed production on the tetraploid mother plant when used as the pollen parents. Based on the ploidy level analysis of their progeny, ‘Fen Tuan Qiang Wei’ produced 1n viable pollen whereas ‘Chun Shui Lü Bo’ and ‘Yu Shi Zhuang’ produced 2n viable pollen. In the meiosis of triploids, the triads, pentads and microcyte in the meiosis products indicated the objective triploid production of euploid pollen grains. Conclusions In this study we reported 1 China triploid rose produces 1n viable pollen, and 2 China triploid roses produce 2n viable pollen, and no anueploid progeny was produced. Our results indicate that the triploids contribute significantly to tetraploids formation in the crossing system of Genus Rosa, and it is possible for breeders to create novel rose types with valuable triploids in the future. With the special triploid resources found in this experiment, Genus Rosa will be an excellent material to study the mechanism of triploids in the future.

scholarly journals Pollen grain traits of oil species from the Novi Sad collection

Genetika ◽  
2009 ◽  
Vol 41 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Jovanka Atlagic ◽  
Ana Marjanovic-Jeromela ◽  
Radovan Marinkovic ◽  
Sreten Terzic
Keyword(s):  
Staining Method ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Grain Morphology ◽  
Pollen Grain ◽  
Viable Pollen ◽  
Continuous Work ◽  
Novi Sad ◽  
Pollen Grain Morphology ◽  
Specific Number

The collection of oil species in Novi Sad contains 12 species represented with 1-4 cultivars or landraces. In the continuous work on this collection in the sense of breeding of some of those species and their usage as a source of 'desirable genes' we analyzed pollen grain morphology (shape and size), as well as pollen viability. To determine mentioned pollen traits we used Axiovert 40C microscope together with a software package (AxioVision LE; Rel.4.3.) for measurement of pollen length and width. Pollen viability was determined using a staining method (ALEXANDER, 1969). The results showed that species differ by pollen grain shape (round, egg-shaped, triangular and rod) as well as by shape of exine (thick and spiky, thick to thin). In some species there was a specific number of apertures present (1-11). The size of viable pollen grains ranged from 29,10/12,58? (coriander) to 176,63/169,94? (oil gourd), while non-viable pollen grains were always smaller (27,27/10,97? to 119,62/100,86?) at the same plant species. Pollen viability of most species was around 80%. Lowest pollen viability was found in white flax (56,98%), and the highest in oil pumpkin (91,43%).

scholarly journals Pollen Grain and Hybridization Studies in the Genus Capsicum

2016 ◽  
Vol 8 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Tomi Lois OLATUNJI ◽  
Joseph Akintade MORAKINYO
Keyword(s):  
Success Rate ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Interspecific Crosses ◽  
Putative Hybrid ◽  
Gene Exchange ◽  
Viable Pollen ◽  
Pollination Success ◽  
Capsicum Species

The current study aimed to evaluate the pollen viability of the commonly cultivated varieties of Capsicum species and assessed the potentials for gene exchange among the genotypes through hybridization studies. Capsicum annuum var. abbreviatum, C. annuum var. acuminatum, C. annuum var. grossum and C. frutescens var. baccatum were the species and varieties used in this study. The present findings indicated that the percentage of pollen viability varied in the studied Capsicum genotypes. The highest pollen viability was obtained in C. annuum var. abbreviatum (96.3%), followed by C. annuum var. grossum (95%), and C. annuum var. acuminatum (91.1%). The lowest pollen viability was recorded in C. frutescens var. baccatum (86.2%). The pollen viability was high in most varieties indicating that meiosis is normal, resulting in viable pollen grains. Several intraspecific and interspecific crosses were performed among the Capsicum genotypes and three putative hybrid fruits were produced. Percentage successes obtained in the crosses were low and comparable in both intra and inter-specific crosses. In the entire crosses pattern, pollination success of 10% was recorded for C. frutescens var. baccatum and C. annuum var. acuminatum. Knowing the nature and viability of pollen grains may help in predicting the success rate of hybridization and the successful crosses between C. frutescens var. baccatum and C. annuum var. acuminatum suggest that these two varieties are the closest genetically. 

scholarly journals Palynological Studies of Three Taxa and One F1 Hybrid in the Genus Talinum Adans

2018 ◽  
Vol 10 (2) ◽  
pp. 175-181
Author(s):  
Oluwabunmi Okerinmola AROGUNDADE ◽  
Hameedat O. LAWAL
Keyword(s):  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Size ◽  
Taxonomic Significance ◽  
F1 Hybrid ◽  
Pollen Shape ◽  
Distinct Features ◽  
Talinum Triangulare

Acetolysed pollen grains of Talinum paniculatum (Jacq.) Gaertn., Talinum triangulare (Jacq.) Willd. pink petals, Talinum triangulare (Jacq.) Willd. white petals and Talinum triangulare (Jacq.) Willd. pink and white petals F1 hybrid were studied in order to document their morphological structures and ascertain features of taxonomic significance among them. All the taxa have generic features which support their classification as a genus as well as distinct features which ascertain their individuality. Generic features include monad pollen unit, acolpate and monocolpate pollen grains as well as circular and ovate pollen shapes. The delimiting features include additional dyads pollen units in T. triangulare white petal and the F1 hybrid of T. triangulare pink and white petals, quadrangular pollen shape in T. paniculatum, bicolpate pollen grain in the F1 hybrid, tricolpate pollens in   T. triangulare white petal and T. paniculatum, tetracolpate pollens in T. triangulare pink petal and T. paniculatum and pentacolpate pollen grains in T. paniculatum only. The shape of the pores in T. paniculatum also separated it from the varieties and hybrid of T. triangulare. Based on the pollen size, the pollens of T. paniculatum are Media (25 - 50 µm) while those of the two varieties of T. triangulare and their F1 hybrid are Magna (50 - 100 µm). The taxa of Talinum in this study can be separated based on their palynological features.

Notes on the size and exine ornamentation of Avena pollen grains

1977 ◽  
Vol 55 (20) ◽  
pp. 2622-2629 ◽  
Author(s):  
R. J. Gornall
Keyword(s):  
Ploidy Level ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Data ◽  
Ploidy Levels ◽  
A Genome ◽  
Exine Ornamentation ◽  
Exine Sculpturing ◽  
Cultivated Species ◽  
Pollen Grain Size

Pollen grain size and exine ornamentation were examined in 13 species of Avena L. (Poaceae), including six A-genome diploids, four tetraploids, and three hexaploids. A cultivated species was represented at each ploidy level. It was found that both pollen size and exine sculpturing patterns showed some correlation with the cytogenetic, morphological, and biochemical evidence which has been used in elucidating the taxonomic relationships within both the A-genome diploids and the hexaploids. However, the pollen data shed less light on relationships within the tetraploids and on relationships between the different ploidy levels. It was observed that the cultivated species at each ploidy level tended to have larger pollen grains and a more complex mode of exine process patterning than their wild relatives. Possible explanations were discussed.

scholarly journals Pollen morphology and viability of some Indian mangroves

2008 ◽  
pp. 60-71 ◽  
Author(s):  
Suparna Gupta ◽  
Arunima Ghosh ◽  
Subrata Maity ◽  
Sauren Das
Keyword(s):  
Pollen Tube ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Tube Length ◽  
Strong Positive Correlation ◽  
Viable Pollen ◽  
The Family ◽  
Indian Mangroves ◽  
Pollen Tube Length

A study on pollen morphology of four common Indian mangroves from Sundarbans mangrove swamps, three species from the family Rhizophoraceae (Bruguiera sexangula Laur., Ceriops tagal Perr.and Rhizophora mucronata Lamk.) and one species from the family Avicenniaceae (Avicennia marina Forsk.) was carried out. Shape of the pollen grains were prolate, prolate spheroidal and subprolate with tricolporate apertures. Surface ornamentation of the studied taxa was reticulate, finely reticulate or scabrate. Pollen grain viability of the said taxa was determined by stain test (1% aceto-orcein) under in situ condition and percentage of viable pollen production was recorded. The result revealed that all the studied taxa produce a fairly good amount of viable pollen grains in natural condition, an indication that they are good propagule producer in the long run. Pollen grain germination and measurements of pollen tube length using different sucrose concentrations (0.2, 0.6, 1.0, 1.2, 1.6 and 2.0%). Maximum pollen fertility and pollen tube length occurred in 2% sucrose solution in case of A. marina and B. sexangula, whereas 1.6% in C. tagal and 1.0% in R. mucronata. A strong positive correlation exist between pollen germination and pollen tube length, but there was a hardly relation between sucrose concentration and pollen tube length.

Features of optative modality in Macedonian language (with emphasis on the functionalities of independent da-construction)

2020 ◽  
pp. 301-323
Author(s):  
Natalya I. Kikilo ◽  
Keyword(s):  
Detailed Analysis ◽  
Present Article ◽  
Literary Language ◽  
Natural Context ◽  
Wide Range ◽  
Verb Forms ◽  
Text Types ◽  
The Future ◽  
The Subject ◽  
Ritual Context

In the Macedonian literary language the analytic da-construction used in an independent clause has a wide range of possible modal meanings, the most common of which are imperative and optative. The present article offers a detailed analysis of the semantics and functions of the Macedonian optative da-construction based on fiction and journalistic texts. The first part of the article deals with the specificities of the optative as a category which primarily considers the subject of a wish. In accordance with the semantic characteristics of this category, optative constructions are used in those discourse text types where the speakers are explicitly designated (the most natural context for the optative is the dialogue). The analysis of the Macedonian material includes instances of atypical usage of the optative da-construction, in which the wish of the subject is not apparent and thereby produces new emotional tonalities perceptible to the reader of a fiction/journalistic text. The study describes Macedonian constructions involving two different verb forms: 1) present tense form (da + praes) and 2) imperfective form (da + impf). These constructions formally designate the hypothetical and counterfactual status of the optative situation, respectively. Thus, the examples in the analysis are ordered according to two types of constructions, which reflect the speaker’s view on the probability of the realisation of his/her wish. Unrealistic wishes can be communicated through the present da-construction, while the imperfective construction denotes situations in which the wish can be realised in the future. The second part of the article is devoted to performative optative da-constructions, which express formulas of speech etiquette, wishes and curses. The analysis demonstrates that these constructions lose their magical functions, when used outside of the ritual context, and begin to function as interjections.

Some influence of the hormonal components in nutrient medium onthe induction of novel structures when obtaining rapeseed haploids through in vitro culture

2018 ◽  
pp. 30-37
Keyword(s):  
Anther Culture ◽  
Hormonal Regulation ◽  
Control Plant ◽  
Pollen Grains ◽  
Control Treatment ◽  
Basic Medium ◽  
Nutrient Media ◽  
Oilseed Crops ◽  
Wide Range

Growth regulators, phytohormones, both natural and artificial, are the main means to control plant ontogenesis. They are involved in regulating the processes of cell differentiation and cell divisions, the formation of tissues and organs, the changes in the rate of growth and development, the duration of the certain stages of ontogenesis. The main classes of phytohormones used in plant biotechnology, in particular, in the induction of haploid structures, are auxins and cytokinins. The mechanism of action of phytohormones on a cell is rather complicated and may have a different character. Understanding the characteristics of the action of phytohormones is complicated by the fact that the system of hormonal regulation of plant life is multicomponent. This is manifested in the fact that the same physiological process is most often influenced not by one, but by several phytohormones, covering a wide range of aspects of cell metabolism. In connection with the foregoing, the purpose of our work was to test a set of nutrient media with different basic composition and different proportions of phytohormones to determine the patterns of their influence on the processes of haploid structure induction in rape anther culture using accessions, developed at the Institute of Oilseed Crops NAAS. The material used was two accessions of winter rapeseed (No. 1 and No. 2) and one sample of spring rapeseed, provided by the Rapeseed Breeding laboratory of the Institute of Oilseed Crops. Incised inflorescences were kept against the background of low temperature of 6–8 ° C for several days, and then, under aseptic conditions, anthers with unripe pollen grains were isolated and planted on nutrient media differing in both basic mineral composition and content of phytohormones. MS (Murashige & Skoog 1962) and B5 (Gamborg et al 1968) media were used as basic media. Phytohormones were added to the basic media in various combinations – BA, 2,4-D, NAA at the concentrations of 0.1-0.6 mg/l. In each treatment up to 300 anthers were cultivated. Differences between treatments were evaluated using standard t-test. Studies have shown that in the anther culture of rapeseed on the tested nutrient media, morphogenic structures of different types (embryoids and callus) were originated. Synthetic auxin 2,4-D, regardless of the composition of the basic medium, caused the formation of structures of both types, though with a low frequency. Phytohormone BA of the cytokinin type had a similar effect. In this case, the frequency of structures was slightly higher, and the developed structures were represented mainly by embryoids. The joint action of cytokinin and auxin was the most favorable for the initiation of morphogenic structures. Such combination of phytohormones caused the formation of these structures with a frequency of 24.5-14.7% in the studied genotypes of winter rape. A similar effect of phytohormones on the induction and development of morphogenic structures was also observed in spring rape. In this case, a single basic MS medium was used. The experiment included treatments where phytohormones were absent (control), as well as various combinations of auxin and cytokinin. In the control treatment, the formation of new structures was not noted. In treatments with phytohormones, in addition to the medium with the combination of auxin and cytokinin, the medium in which only cytokinin was present was also rather effective. The treatment in which the action of auxin 2,4-D was combined with the action of another auxin, NAA, turned out to be practically ineffective. Thus, it was found that for the induction of morphogenic structures from microspores in rape anther culture of the tested genotypes, the combination of cytokinin with auxin, or the use of only single cytokinin BA without other phytohormones, had the most positive effect.

scholarly journals Frequency Division Multiplexing of Terahertz Waves Realized by Diffractive Optical Elements

2021 ◽  
Vol 11 (14) ◽  
pp. 6246
Author(s):  
Paweł Komorowski ◽  
Patrycja Czerwińska ◽  
Mateusz Kaluza ◽  
Mateusz Surma ◽  
Przemysław Zagrajek ◽  
...  
Keyword(s):  
Frequency Division Multiplexing ◽  
Diffractive Optical Elements ◽  
Frequency Division ◽  
Terahertz Waves ◽  
Optical Elements ◽  
Telecommunication Systems ◽  
Wide Range ◽  
The Future ◽  
Wireless Telecommunication ◽  
Finite Distance

Recently, one of the most commonly discussed applications of terahertz radiation is wireless telecommunication. It is believed that the future 6G systems will utilize this frequency range. Although the exact technology of future telecommunication systems is not yet known, it is certain that methods for increasing their bandwidth should be investigated in advance. In this paper, we present the diffractive optical elements for the frequency division multiplexing of terahertz waves. The structures have been designed as a combination of a binary phase grating and a converging diffractive lens. The grating allows for differentiating the frequencies, while the lens assures separation and focusing at the finite distance. Designed structures have been manufactured from polyamide PA12 using the SLS 3D printer and verified experimentally. Simulations and experimental results are shown for different focal lengths. Moreover, parallel data transmission is shown for two channels of different carrier frequencies propagating in the same optical path. The designed structure allowed for detecting both signals independently without observable crosstalk. The proposed diffractive elements can work in a wide range of terahertz and sub-terahertz frequencies, depending on the design assumptions. Therefore, they can be considered as an appealing solution, regardless of the band finally used by the future telecommunication systems.

Digital Authoritarianism and the Future of Human Rights

2021 ◽  
pp. 1-27
Author(s):  
Tiberiu Dragu ◽  
Yonatan Lupu
Keyword(s):  
Human Rights ◽  
New Technologies ◽  
Theoretic Model ◽  
Human Rights Abuses ◽  
Human Rights Regime ◽  
Wide Range ◽  
The Future ◽  
Technological Developments ◽  
Game Theoretic ◽  
Strategic Context

Abstract How will advances in digital technology affect the future of human rights and authoritarian rule? Media figures, public intellectuals, and scholars have debated this relationship for decades, with some arguing that new technologies facilitate mobilization against the state and others countering that the same technologies allow authoritarians to strengthen their grip on power. We address this issue by analyzing the first game-theoretic model that accounts for the dual effects of technology within the strategic context of preventive repression. Our game-theoretical analysis suggests that technological developments may not be detrimental to authoritarian control and may, in fact, strengthen authoritarian control by facilitating a wide range of human rights abuses. We show that technological innovation leads to greater levels of abuses to prevent opposition groups from mobilizing and increases the likelihood that authoritarians will succeed in preventing such mobilization. These results have broad implications for the human rights regime, democratization efforts, and the interpretation of recent declines in violent human rights abuses.

Report on CLEF 2019

2019 ◽  
Vol 53 (2) ◽  
pp. 108-118
Author(s):  
Martin Braschler ◽  
Linda Cappellato ◽  
Fabio Crestani ◽  
Nicola Ferro ◽  
Gundula Heinatz Bürki ◽  
...  
Keyword(s):  
Standard Test ◽  
Future Perspectives ◽  
Research Papers ◽  
Test Collections ◽  
Lessons Learnt ◽  
Wide Range ◽  
The Future ◽  
20Th Anniversary

This is a report on the tenth edition of the Conference and Labs of the Evaluation Forum (CLEF 2019), held from September 9--12, 2019, in Lugano, Switzerland. CLEF was a four day event combining a Conference and an Evaluation Forum. The Conference featured keynotes by Bruce Croft, Yair Neuman, and Miguel Martínez, and presentation of peer reviewed research papers covering a wide range of topics in addition to many posters. The Evaluation Forum consisted to nine Labs: CENTRE, CheckThat, eHealth, eRisk, ImageCLEF, LifeCLEF, PAN, PIR-CLEF, and ProtestNews, addressing a wide range of tasks, media, languages, and ways to go beyond standard test collections. CLEF 2019 marked the 20th anniversary of CLEF, which was celebrated with a dedicated session and a book on the lessons learnt in twenty years of evaluation activities and the future perspectives for CLEF. CLEF 2019 also introduced the Industry Days to further extend the reach and impact of CLEF.

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